Journal articles on the topic 'Reverse diabetes naturally'

The incidence of metabolic disorders like type 2 diabetes (T2D) and obesity continue to increase. Although it is evident that the increasing incidence of diabetes confers a global societal and economic burden, the mechanisms responsible for the increased incidence of T2D are not well understood. Extensive efforts to understand the association of early-life perturbations with later onset of metabolic diseases, the founding principle of developmental origins of health and disease, have been crucial in determining the mechanisms that may be driving the pathogenesis of T2D. As the programming of the epigenome occurs during critical periods of development, it has emerged as a potential molecular mechanism that could occur early in life and impact metabolic health decades later. In this review, we critically evaluate human and animal studies that illustrated an association of epigenetic processes with development of T2D as well as intervention strategies that have been employed to reverse the perturbed epigenetic modification or reprogram the naturally occurring epigenetic marks to favor improved metabolic outcome. We highlight that although our understanding of epigenetics and its contribution toward developmental origins of T2D continues to grow, whether epigenetics is a cause, consequence, or merely a correlation remains debatable due to the many limitations/challenges of the existing epigenetic studies. Finally, we discuss the potential of establishing collaborative research efforts between different disciplines, including physiology, epigenetics, and bioinformatics, to help advance the developmental origins field with great potential for understanding the pathogenesis of T2D and developing preventive strategies for T2D.

Spherical nucleic acid (SNA) gold nanoparticle conjugates (13-nm-diameter gold cores functionalized with densely packed and highly oriented nucleic acids) dispersed in Aquaphor have been shown to penetrate the epidermal barrier of both intact mouse and human skin, enter keratinocytes, and efficiently down-regulate gene targets. ganglioside-monosialic acid 3 synthase (GM3S) is a known target that is overexpressed in diabetic mice and responsible for causing insulin resistance and impeding wound healing. GM3S SNAs increase keratinocyte migration and proliferation as well as insulin and insulin-like growth factor-1 (IGF1) receptor activation under both normo- and hyperglycemic conditions. The topical application of GM3S SNAs (50 nM) to splinted 6-mm-diameter full-thickness wounds in diet-induced obese diabetic mice decreases local GM3S expression by >80% at the wound edge through an siRNA pathway and fully heals wounds clinically and histologically within 12 d, whereas control-treated wounds are only 50% closed. Granulation tissue area, vascularity, and IGF1 and EGF receptor phosphorylation are increased in GM3S SNA-treated wounds. These data capitalize on the unique ability of SNAs to naturally penetrate the skin and enter keratinocytes without the need for transfection agents. Moreover, the data further validate GM3 as a mediator of the delayed wound healing in type 2 diabetes and support regional GM3 depletion as a promising therapeutic direction.

Abstract Interleukin-1 (IL-1) is a multifunctional cytokine with profound effects on ovarian function. The effects of IL-1 on ovarian steroidogenesis have been demonstrated in several species. IL-1 mRNA levels are increased in the thecal layer of the ovulating follicle and IL-1β has been shown to induce ovulations in vitro. In this study we have investigated the presence and distribution of the mRNAs for type I IL-1 receptor (IL-1RtI) and for the naturally occurring IL-1 receptor antagonist (IL-1ra) in ovaries of adult cycling rats, to elucidate the target cells for IL-1 action. We have demonstrated the presence of mRNA for both substances by in situ hybridisation and reverse transcription PCR. mRNA for IL-1RtI was not found in primordial follicles but was abundant in the granulosa and thecal layer in developing follicles with stronger signals in the granulosa layer. In the preovulatory and ovulatory follicles, there was a further increase in the signal for IL-1RtI mRNA in the thecal layer compared with the granulosa layer. Corpora lutea were weakly positive at all stages and atretic follicles were largely negative. No mRNA was detected in oocytes of any stage. mRNA for IL-1ra showed a similar distribution to that of IL-1RtI. The changes in distribution suggest an action of IL-1 on rat granulosa cells during follicular development and on thecal cells during ovulation. Journal of Endocrinology (1997) 152, 11–17

PDE4 cyclic nucleotide phosphodiesterases regulate cAMP abundance in cells and therefore regulate numerous processes, including cell growth and differentiation. The rat PDE4A5 isoform (human homolog PDE4A4) interacts with the AIP protein (also called XAP2 or ARA-9). Germline mutations inAIPoccur in approximately 20% of patients with Familial Isolated Pituitary Adenoma (FIPA) and 20% of childhood-onset simplex somatotroph adenomas. We therefore examined the protein expression of PDE4A4 and the closely related isoform PDE4A8 in normal human pituitary tissue and in pituitary adenomas. PDE4A4 had low expression in normal pituitary but was significantly overexpressed in somatotroph, lactotroph, corticotroph and clinically nonfunctioning gonadotroph adenomas (P<0.0001 for all subtypes). Likewise, PDE4A8 was expressed in normal pituitary and was also significantly overexpressed in the adenoma subtypes (P<0.0001 for all). Among the different adenoma subtypes, corticotroph and lactotroph adenomas were the highest and lowest expressed for PDE4A4, respectively, whereas the opposite was observed for PDE4A8. Naturally occurring oncogenic variants in AIP were shown by a two-hybrid assay to disrupt the ability of AIP to interact with PDE4A5. A reverse two-hybrid screen identified numerous additional variants in the tetratricopeptide repeat (TPR) region of AIP that also disrupted its ability to interact with PDE4A5. The expression of PDE4A4 and PDE4A8 in normal pituitary, their increased expression in adenomatous pituitary cells where AIP is meant to participate, and the disruption of the PDE4A4–AIP interaction byAIPmutants may play a role in pituitary tumorigenesis.

The flowering plant genus Alisma, which belongs to the family Alismataceae, comprises 11 species, including Alisma orientale, Alisma canaliculatum, and Alisma plantago-aquatica. Alismatis rhizome (Ze xie in Chinese, Takusha in Japanese, and Taeksa in Korean, AR), the tubers of medicinal plants from Alisma species, have long been used to treat inflammatory diseases, hyperlipidemia, diabetes, bacterial infection, edema, oliguria, diarrhea, and dizziness. Recent evidence has demonstrated that its extract showed pharmacological activities to effectively reverse cancer-related molecular targets. In particular, triterpenes naturally isolated from AR have been found to exhibit antitumor activity. This study aimed to describe the biological activities and plausible signaling cascades of AR and its main compounds in experimental models representing cancer-related physiology and pathology. Available in vitro and in vivo studies revealed that AR extract possesses anticancer activity against various cancer cells, and the efficacy might be attributed to the cytotoxic and antimetastatic effects of its alisol compounds, such as alisol A, alisol B, and alisol B 23-acetate. Several beneficial functions of triterpenoids found in AR might be due to p38 activation and inhibition of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathways. Moreover, AR and its triterpenes inhibit the proliferation of cancer cells that are resistant to chemotherapy. Thus, AR and its triterpenes may play potential roles in tumor attack, as well as a therapeutic remedy alone and in combination with other chemotherapeutic drugs.

ObjectiveThe concept of using naturally occurring compounds such as polyenylphosphatidylcholine (PPC) as an adjunctive therapy to treat non-alcoholic fatty liver disease (NAFLD) and alleviate or reverse hepatic steatosis appears a very attractive option for liver protection. We aim to evaluate if PPC adjunctive therapy can effectively improve the ultrasonographic features of NAFLD in routine clinical practice in Russian patients with cardiometabolic comorbidities.DesignThis 24-week, observational, prospective study was carried out in 174 medical sites across 6 federal districts of Russia. A total of 2843 adult patients with newly diagnosed NAFLD, who had a least one of four comorbidities, namely overweight/obesity, hypertension, type 2 diabetes mellitus and hypercholesterolaemia, and who received PPC as an adjunctive treatment to standard care, were enrolled. The assessment of liver ultrasonography was qualitative.ResultsOverall, 2263 (79.6%) patients had at least two metabolic comorbidities associated with NAFLD, and overweight/obesity was the most common comorbidity reported in 2298 (80.8%) patients. Almost all study participants (2837/2843; 99.8%) were prescribed 1.8 g of PPC administered three times daily. At baseline, the most frequently identified abnormalities on ultrasound were liver hyperechogenicity (84.0% of patients) and heterogeneous liver structure (62.9%). At 24 weeks, a significant (p<0.05) improvement in liver echogenicity and in liver structure was observed in 1932/2827 (68.3%) patients (95% CI 66.6% to 70.1%) and in 1207/2827 (42.7%) patients (95% CI 40.9% to 44.5%), respectively. The analysis of ultrasonographic signs by number of comorbidities revealed similar findings—liver echogenicity improved in 67.2%–69.3% and liver structure in 35.6%–45.3% of patients depending on the number of comorbidities.ConclusionThis study showed that PPC adjunctive therapy may be useful in improving the ultrasonographic features of NAFLD in patients with associated cardiometabolic comorbidities. It also supports evidence regarding the role of PPC in the complex management of NAFLD.

Background. Refractory wound healing is a severe complication of diabetes with a significant socioeconomic burden. Whereas current therapies are insufficient to accelerate repair, stem cell-based therapy is increasingly recognized as an alternative that improves healing outcomes. The aim of the present study is to explore the role of cycloastragenol (CAG), a naturally occurring compound in Astragali Radix, in ameliorating refractory cutaneous wound healing in vitro, which may provide a new insight into therapeutic strategy for diabetic wounds. Methods. Human epidermal stem cells (EpSCs) obtained from nine patients were exposed to CAG, with or without DKK1 (a Wnt signaling inhibitor). A lentiviral short hairpin RNA (shRNA) system was used to establish the telomerase reverse transcriptase (TERT) and β-catenin knockdown cell line. Cell counting kit-8, scratch wound healing, and transwell migration assay were used to determine the effects of CAG in cell growth and migration. The activation of TERT, β-catenin, and c-Myc was determined using real-time qPCR and western blot analysis. Chromatin immunoprecipitation (ChIP) was performed to evaluate the associations among CAG, TERT, and Wnt/β-catenin signals. Results. CAG not only promoted the proliferation and migration ability of EpSCs but also increased the expression levels of TERT, β-catenin, c-Myc. These effects of CAG were most pronounced at a dose of 0.3 μM. Notably, the CAG-promoted proliferative and migratory abilities of EpSCs were abrogated in TERT and β-catenin-silenced cells. In addition, the ChIP results strongly suggested that CAG-modulated TERT was closely associated with the activation of Wnt/β-catenin signaling. Conclusion. Our data indicate that CAG is a TERT activator of EpSCs and is associated with their proliferation and migration, a role it may play through the activation of Wnt/β-catenin signaling.

ABSTRACT The chicken pituitary gland contains a number of naturally occurring, developmentally regulated forms of GH which have identical molecular weights but differ in their isoelectric points. In order to characterize their biological properties, each must be separated from non-GH proteins and other forms of GH. Chicken GH (cGH) was separated from other pituitary proteins by immunoaffinity chromatography using an anti-GH monoclonal antibody covalently linked to Sepharose 4B. The cGH eluted from this column as a single peak and migrated as a single band during sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), but showed multiple bands on isoelectric focussing. This material was chromatographed on a high-performance cation exchange column, and separation of charge isomers was monitored by a combination of isoelectric focussing and immunoblotting. Chicken GH eluted from this column in two distinct peaks. The minor peak (cGH P1) contained an isomer with an isoelectric point of 6·86 and the major peak (cGH P2) an isomer with an isoelectric point of 7·52. Each isomer migrated as a single band during isoelectric focussing and SDS-PAGE (Mr = 23 500), and as a single peak during high-performance gel permeation chromatography and reverse-phase high-performance liquid chromatography. Analysis of cGH P2 through 30 cycles in a gas-phase microsequencer gave an amino acid sequence identical to that predicted by translation of the GH complementary DNA nucleotide sequence. This single charge isomer increased the rate of lipolysis in chicken adipose tissue explants by about fourfold and was able to displace 125I-labelled cGH from binding sites in liver membranes with a dissociation constant of about 4 nmol/l. The output of insulin-like growth factor-I by hepatocytes in culture was increased from a basal rate of 50·4±11·6 (mean ± s.e.m.) to 787·9 ± 98·6 pg/6 × 106 cells per 48 h by two separate pulses of 1 μg cGH P2/ml. An i.v. injection of cGH P2 (15 μg/kg body weight) decreased the thyroxine:tri-iodothyronine ratio in serum of adult hens from 15·71 to 4·44, indicating an increase in 5′-monodeiodinase activity. These results demonstrate that the single most abundant charge isomer of chicken pituitary GH is likely to contain all the biological activity ascribed to the hormone. Journal of Endocrinology (1990) 125, 207–215

Non-alcoholic fatty liver (NAFL) disease (NAFLD) affects 30% of overweight adolescents and increases the risk of type 2 diabetes mellitus (T2D). Resveratrol is a naturally occurring compound with potential to reverse NAFL and its associated insulin resistance in adults. The use of resveratrol to reduce risk for T2D through its effect on NAFL has not been examined to date in youth. This paper provides a literature review and protocol for a 30 day proof of principle trial of resveratrol in a population of adolescents at risk for T2D. This randomized double-blind controlled trial is designed with the primary objective of evaluating a twice daily supplementation of 75 mg of resveratrol for safety and tolerability in overweight and obese adolescent subjects (13 to <18 years of age) with NAFL. Secondary objectives are to determine the effect size of the intervention on hepatic steatosis and whole body insulin sensitivity. Adolescents in the intervention arm (n = 10) will receive oral supplementation of resveratrol 75 mg twice daily (with breakfast and dinner) for a total daily dose of 150 mg for the duration of 30 days. The comparison group (n = 10) will receive a placebo twice daily for 30 days. Both cases and controls will receive a standardized lifestyle intervention program. Subjects in both groups will be followed for an additional 30 days post intervention for total study duration of approximately 60 days. Primary outcome measures include a primary side effect profile determined by participant interview, a side effect profile determined by serum biochemistry and vital signs. Secondary outcome measures include an oral glucose tolerance test, liver and cardiac fat content measured by magnetic resonance spectroscopy, anthropometric measures of overweight/obesity, inflammatory markers, and cardiac function and morphology measured with ultrasonography. Additional outcome measures include serum concentrations of resveratrol, compliance to protocol, physical activity, and nutritional assessment. This study will determine the safety and tolerability of resveratrol in an overweight adolescent population and inform the design of a larger randomized controlled trial.

Increased endothelin-1 (ET-1), vascular endothelial growth factor (VEGF) and activation of protein kinase C (PKC) are co-contributors to endothelial hyperpermeability in diabetes. Several lines of evidence have suggested a hypothesis that activation of specific PKC isoforms are the causative factor in ET-1 and VEGF mediated endothelial dysfunction. In the present study, we tested this hypothesis with hypocrellin A, a naturally occurring PKC inhibitor from a Chinese plant. Human umbilical vein endothelial cells (HUVECs) were incubated with 20 mM glucose in both the presence and absence of hypocrellin A, after which, the protein expression and release of VEGF and mRNA expression and release of ET-1 were measured. VEGF and ET-1 were released into the medium and expressions of VEGF protein and ET-1 mRNA were significantly increased in HUVECs incubated with 20 mM glucose. Hypocrellin A (150 nM) significantly decreased VEGF release (117 ± 3 vs. 180 ± 11 pg/mg, p < 0.05) and VEGF protein expression (from 130 ± 14% to 88 ± 18.5%, p < 0.05). ET-1 release was also reduced in hypocrellin A treated HUVECs (63.3 ± 9.9 vs. 75.2 ± 12.6 ng/mg). Hypocrellin A significantly reversed the effect of high glucose on ET-1 mRNA expression ( p < 0.05). The results revealed that PKC activation plays a pivotal role in VEGF and ET-1 mediated endothelial permeability. The naturally occurring compound hypocrellin A may be a potentially novel treatment for endothelial dysfunction in diabetes.

Background/Aims: The goal of this study was to determine the effect of dietary genistein (naturally occurring phytoestrogen) on jejunal secretory function in a clinically relevant model of diabetes and obesity, the leptin-defIcient ob/ob mouse. Methods: We measured transepithelial short circuit current (Isc), across freshly isolated segments of jejunum from 12-week old male and female ob/ob and lean C57Bl/6J mice fed a genistein diet (600 mg genistein/kg diet) for 4-weeks. Separate segments of jejunum were frozen for western blot determination of key proteins involved in secretory transport. Results: Basal Isc was signifIcantly decreased (by 33%, P<0.05) in ob/ob females versus leans, and genistein-diet reversed this. Similarly, in males, basal Isc was decreased (by 47%, P<0.05) in ob/ob mice versus leans, and genistein-diet reversed this. Inhibition with either clotrimazole (100 µM, bilateral) or ouabain (100 µM, basolateral) was signifIcantly reduced in ob/ob mice compared to leans (P<0.05), and genistein-diet reversed clotrimazole-sensitive inhibition in ob/ob females, and reversed the ouabain-sensitive inhibition in males (indicating sex-dependent mechanisms). Our data suggested that PDE3 levels were dysregulated in ob/ob females and genistein reversed this. Expression of total CFTR (normalized to actin) was signifIcantly decreased ∼80% (P<0.05) in all ob/ob mice compared to leans, and genistein-diet was without effect. Expression of total NKCC1 (normalized to actin) was signifIcantly decreased ∼80% (P<0.05) in ob/ob male mice versus leans, and genistein-diet reversed this. Conclusions: Our data suggests that the reduced basal jejunal Isc in ob/ob female mice is a consequence of reduced CFTR expression, decreased activities of the basolateral KCa channel and Na+/K+-ATPase, and in male mice reduced basal jejunal Isc is a consequence of reduced CFTR and NKCC1 expression, along with decreased activities of the basolateral KCa channel and Na+/K+-ATPase. Genistein-diet has beneficial effects on basal Isc mediated by sex-dependent mechanisms in diabetic mice: in females via increased KCa-sensitive Isc and in males via increased Na+/K+-ATPase activity and increased NKCC1 expression. Improved understanding of intestinal dysfunctions in the ob/ob jejunum, may allow for the development of novel drug targets to treat obesity and diabetes, and may also be of benefit in CF-related diabetes.

The prevalence of type 2 diabetes (T2D) has been rising dramatically in many countries around the world. The main signatures of T2D are insulin resistance and dysfunction of β-cells. While there are several pharmaceutical therapies for T2D, no effective treatment is available for reversing the functional decline of pancreatic β-cells in T2D patients. It has been well recognized that glucagon-like peptide-1 (GLP-1), which is an incretin hormone secreted from intestinal L-cells, plays a vital role in regulating glycemic homeostasis via potentiating glucose-stimulated insulin secretion and promoting β-cell function. We found that genipin, a natural compound from Elli, can directly target intestinal L-cells, leading to the secretion of GLP-1. Incubation of the cells with genipin elicited a rapid increase in intracellular Ca2+. Inhibition of PLC ablated genipin-stimulated Ca2+ increase and GLP-1 secretion, suggesting that genipin-induced GLP-1 release from cells is dependent on the PLC/Ca2+ pathway. In vivo, acute administration of genipin stimulated GLP-1 secretion in mice. Chronically, treatment with genipin via oral gavage at 50 mg/kg/day for 6 weeks reversed hyperglycemia and insulin resistance in high-fat-diet (HFD)-induced obese mice. Moreover, genipin alleviated the impaired lipid metabolism and decreased lipid accumulation in the liver of obese mice. These results suggest that naturally occurring genipin might potentially be a novel agent for the treatment of T2D and diet-induced fatty liver disease.

Abstract. Changes in plasma T4 levels were investigated in prepubertal and adult female goats during the course of an experimental Trypanosoma congolense infection. A significant decline in the T4 levels was observed within 1 week of trypanosome challenge. The levels remained low up to the end of the 7th weeks when prepubertal goats received a trypanocidal treatment, whereafter the values started to rise to normal pre-infection values. The post-infection plasma T4 values in the untreated adult goats did not return to normal except in one resistant goat which recovered naturally after 16 weeks of the infection. The thyroid glands of chronically infected and untreated adult goats revealed marked atrophy, fibrosis and colloidopathy. It is concluded that trypanosomiasis rapidly impairs thyroid gland function in susceptible animals, but these changes can be reversed by early trypanocidal treatment before marked degenerative changes become evident or following self cure in resistant animals.

Insulin resistance and a progressive decline in functionalβ-cell mass are hallmarks of developing type 2 diabetes (T2D). Thus, searching for natural, low-cost compounds to target these two defects could be a promising strategy to prevent the pathogenesis of T2D. Here, we show that dietary intake of flavonol kaempferol (0.05% in the diet) significantly ameliorated hyperglycemia, hyperinsulinemia, and circulating lipid profile, which were associated with the improved peripheral insulin sensitivity in middle-aged obese mice fed a high-fat (HF) diet. Kaempferol treatment reversed HF diet impaired glucose transport-4 (Glut4) and AMP-dependent protein kinase (AMPK) expression in both muscle and adipose tissues from obese mice.In vitro, kaempferol increased lipolysis and prevented high fatty acid-impaired glucose uptake, glycogen synthesis, AMPK activity, and Glut4 expression in skeletal muscle cells. Using another mouse model of T2D generated by HF diet feeding and low doses of streptozotocin injection, we found that kaempferol treatment significantly improved hyperglycemia, glucose tolerance, and blood insulin levels in obese diabetic mice, which are associated with the improved isletβ-cell mass. These results demonstrate that kaempferol may be a naturally occurring anti-diabetic agent by improving peripheral insulin sensitivity and protecting against pancreaticβ-cell dysfunction.

ABSTRACT While intrasexual competition for mates is generally considered to be an androgen-dependent characteristic of reproductively active males, in the Wilson's phalarope (Phalaropus tricolor) it is the female that acquires the brighter nuptial plumage and aggressively competes for access to the less aggressive males. Despite this pronounced sex-role reversal, circulating sex steroid hormones of breeding phalaropes are similar to those of avian species displaying traditional male–female reproductive roles. To investigate whether these behavioural and morphological steroid-dependent differences may be due to differences in target organ metabolism of circulating androgen, [3H]androstenedione in the presence of an NADPH-generating system was incubated with homogenates of brain, pituitary and skin of male and female Wilson's phalaropes collected from a naturally breeding population. Oestrone, 5α-androstanedione and 5β-androstanedione were measured as endpoints of aromatization, 5α-reduction and 5β-reduction respectively. Aromatase activity in the anterior hypothalamus/preoptic area (AHPOA) and posterior hypothalamus was greater in breeding males with high circulating concentrations of testosterone than in females, and activity in the AHPOA was greater in breeding than in non-breeding males (with low circulating testosterone). Aromatase levels did not differ in septum, archistriatum, hyperstriatum or pituitary. 5α- and 5β-reductase were detected in all neuroendocrine tissues sampled and although there were no significant male–female differences, 5α-reductase was greater in the AHPOA of breeding than of non-breeding males. We infer from this that the behavioural sex-role reversal of phalaropes is unlikely to be accounted for by differences in androgen metabolism in neural targets, although the capacity to form greater quantities of oestrogenic and 5α-reduced metabolites in the AHPOA of breeding males may be linked to the expression of masculine copulatory behaviours. Aromatase activity was not detected in skin containing a sexually dimorphic feather tract; however, 5α- and 5β-reductase activities were significantly higher in females than in males and may account for the brighter nuptial plumage of females. These data suggest that alternate determinants of neural responsiveness such as sex-steroid receptor abundance or neural circuitry may underlie atypical sexual behaviours in phalaropes. Journal of Endocrinology (1989) 122, 573–581

3-Methoxypterostilbene is a naturally occurring stilbene with potential in the treatment of diabetes. The preclinical pharmacokinetics and pharmacodynamics of 3-methoxypterostilbene were evaluated in the present study. The right jugular veins of male Sprague-Dawley rats were cannulated. The rats were dosed 10 mg/kg or 100 mg/kg of 3-methoxypterostilbene intravenously (IV) or orally (PO), respectively. Serum and urine samples were analyzed using a previously validated reversed-phase HPLC method. Serum AUC, serumt1/2, urinet1/2,Cltotal, and Vd for IV dosing were48.1±23.8 μg/h/mL,18.9±10.9 h,9.54±1.51 h,47.8±23.7 L/h/kg, and5.11±0.38 L/kg, respectively (mean ± SEM,n=4) . Serum AUC, serumt1/2, urinet1/2,Cltotal, and Vd for PO dosing were229±44.6 μg/h/mL,73.3±8.91 h,20.6±3.01 h,0.48±0.008 L/h/kg, and52.0±10.5 L/kg, respectively (mean ± SEM,n=4). Bioavailability of the stilbene was determined to be 50.6% ± 10.0%. A 3-methoxypterostilbene glucuronidated metabolite was detected in both serum and urine. 3-Methoxypterostilbene exhibited antidiabetic activity includingα-glucosidase andα-amylase inhibition as well as concentration-dependent antioxidant capacity similar to resveratrol. 3-Methoxypterostilbene also exhibited anti-inflammatory activity. 3-Methoxypterostilbene appears to be a bioactive compound and may be useful in reducing postprandial hyperglycemia.

Hydrogen sulphide (H2S), a naturally occurring gas exerts physiological effects by opening KATP channels. Anti-diabetic drugs (e.g. glibenclamide) block KATP channels and abrogate H2S-mediated physiological responses which suggest that H2S may also regulate insulin secretion by pancreatic β-cells. To investigate this hypothesis, insulin-secreting (HIT-T15) cells were exposed to NaHS (100 μM) and the KATP channel-driven pathway of insulin secretion was tracked with various fluorescent probes. The concentration of insulin released from HIT-T15 cells decreased significantly after NaHS exposure and this effect was reversed by the addition of glibenclamide (10 μM). Cell viability and intracellular ATP and glutathione (GSH) levels remained unchanged, suggesting that changes in insulin secretion were not ATP linked or redox dependent. Through fluorescence imaging studies, it was found that K+ efflux occurs in cells exposed to NaHS. The hyperpolarised cell membrane, a result of K+ leaving the cell, prevents the opening of voltage-gated Ca2+ channels. This subsequently prevents Ca2+ influx and the release of insulin from HIT-T15 cells. This data suggest that H2S reduces insulin secretion by a KATP channel-dependent pathway in HIT-T15 cells. This study reports the molecular mechanism by which H2S reduces insulin secretion and provides further insight into a recent observation of increased pancreatic H2S production in streptozotocin-diabetic rats.

Accumulating evidence demonstrates that the risk of osteoporotic fractures increases in patients with diabetes mellitus. Thus, diabetes-induced bone fragility has recently been recognized as a diabetic complication. As the fracture risk is independent of the reduction in bone mineral density, deterioration in bone quality may be the main cause of bone fragility. Coumarin exists naturally in many plants as phenylpropanoids and is present in tonka beans in significantly high concentrations. This study investigated whether coumarin ameliorated the impaired bone turnover and remodeling under diabetic condition. The in vitro study employed murine macrophage Raw 264.7 cells differentiated to multinucleated osteoclasts with receptor activator of nuclear factor-κΒ ligand (RANKL) in the presence of 33 mM glucose and 1–20 μM coumarin for five days. In addition, osteoblastic MC3T3-E1 cells were exposed to 33 mM glucose for up to 21 days in the presence of 1–20 μM coumarin. High glucose diminished tartrate-resistant acid phosphatase activity and bone resorption in RANKL-differentiated osteoclasts, accompanying a reduction of cathepsin K induction and actin ring formation. In contrast, coumarin reversed the defective osteoclastogenesis in diabetic osteoclasts. Furthermore, high glucose diminished alkaline phosphatase activity and collagen type 1 induction of osteoblasts, which was strongly enhanced by submicromolar levels of coumarin to diabetic cells. Furthermore, coumarin restored the induction of RANK and osteoprotegerin in osteoclasts and osteoblasts under glucotoxic condition, indicating a tight coupling of osteoclastogenesis and osteoblastogenesis. Coumarin ameliorated the impaired bone turnover and remodeling in diabetic osteoblasts and osteoclasts by suppressing the interaction between advanced glycation end product (AGE) and its receptor (RAGE). Therefore, coumarin may restore optimal bone turnover of osteoclasts and osteoblasts by disrupting the hyperglycemia-mediated AGE–RAGE interaction.

In forensic toxicology, gamma-hydroxybutyrate (GHB) still represents one of the most challenging drugs of abuse in terms of analytical detection and interpretation. Given its rapid elimination, the detection window of GHB in common matrices is short (maximum 12 h in urine). Additionally, the differentiation from naturally occurring endogenous GHB, is challenging. Thus, novel biomarkers to extend the detection window of GHB are urgently needed. The present study aimed at searching new potential biomarkers of GHB use by means of mass spectrometry (MS) metabolomic profiling in serum (up to 16.5 h) and urine samples (up to 8 h after intake) collected during a placebo-controlled crossover study in healthy men. MS data acquired by different analytical methods (reversed phase and hydrophilic interaction liquid chromatography; positive and negative electrospray ionization each) were filtered for significantly changed features applying univariate and mixed-effect model statistics. Complementary to a former study, conjugates of GHB with glycine, glutamate, taurine, carnitine and pentose (ribose) were identified in urine, with particularly GHB-pentose being promising for longer detection. None of the conjugates were detectable in serum. Therein, mainly energy metabolic substrates were identified, which may be useful for more detailed interpretation of underlying pathways but are too unspecific as biomarkers.

Abstract A set of putative natural T regulatory epitopes (Tregitopes, derived from IgG) have been identified, which have suppressive effects both in vitro and in vivo. These Tregitopes are promiscuous, bind highly to MHC class II and are highly conserved in multiple species. In this study, we further investigated the mechanisms of suppression by Tregitopes. We first demonstrated that neither CFA nor IFA emulsified Tregitopes peptides per se are immunogenic in vivo. Administration of Tregitopes by IFA upregulated FoxP3+ T cells and reduced specific CD4+ T cell responses in OVA TCR transgenic and normal Balb/c mice. Interestingly, we found that Tregitopes activated natural, but not inducible Tregs. Furthermore, B cells that are pulsed with Tregitopes and a target antigen OVA in vitro acquired tolerogenic phenotypes. These B cells can suppress both T cell and antibody responses to OVA protein in vivo. In NOD mice, administration of Tregitopes resulted in delayed onset of type I diabetes and even reversed hyperglycemia in the majority of new onset diabetic mice. Together, our results suggest that Tregs induced by Tregitopes represents a new paradigm for treatment of autoimmune disease (Supported by NIH grants RO1 AI035622, RO1 DK068343 and R43 DK081261).

Diabetes-associated visual cycle impairment has been implicated in diabetic retinopathy, and chronic hyperglycemia causes detrimental effects on visual function. Chrysin, a naturally occurring flavonoid found in various herbs, has anti-inflammatory, antioxidant, and neuroprotective properties. The goal of the current study was to identify the retinoprotective role of chrysin in maintaining robust retinoid visual cycle-related components. The in vitro study employed human retinal pigment epithelial (RPE) cells exposed to 33 mM of glucose or advanced glycation end products (AGEs) in the presence of 1–20 μM chrysin for three days. In the in vivo study, 10 mg/kg of chrysin was orally administrated to db/db mice. Treating chrysin reversed the glucose-induced production of vascular endothelial growth factor, insulin-like growth factor-1, and pigment epithelium-derived factor (PEDF) in RPE cells. The outer nuclear layer thickness of chrysin-exposed retina was enhanced. The oral gavage of chrysin augmented the levels of the visual cycle enzymes of RPE65, lecithin retinol acyltransferase (LRAT), retinol dehydrogenase 5 (RDH5), and rhodopsin diminished in db/db mouse retina. The diabetic tissue levels of the retinoid binding proteins and the receptor of the cellular retinol-binding protein, cellular retinaldehyde-binding protein-1, interphotoreceptor retinoid-binding protein and stimulated by retinoic acid 6 were restored to those of normal mouse retina. The presence of chrysin demoted AGE secretion and AGE receptor (RAGE) induction in glucose-exposed RPE cells and diabetic eyes. Chrysin inhibited the reduction of PEDF, RPE 65, LRAT, and RDH5 in 100 μg/mL of AGE-bovine serum albumin-exposed RPE cells. The treatment of RPE cells with chrysin reduced the activation of endoplasmic reticulum (ER) stress. Chrysin inhibited the impairment of the retinoid visual cycle through blocking ER stress via the AGE-RAGE activation in glucose-stimulated RPE cells and diabetic eyes. This is the first study demonstrating the protective effects of chrysin on the diabetes-associated malfunctioned visual cycle.

Background: Accumulating experimental data supports the capacity of natural compounds to intervene in complicated molecular pathways underlying the pathogenesis of certain human morbidities. Among them, diabetes is now a world’s epidemic associated with increased risk of death; thus, the detection of novel anti-diabetic agents and/or adjuvants is of vital importance. Alkaloids represent a diverse group of natural products with a range of therapeutic properties; during the last 20 years, published research on their anti-diabetic capacity has been tremendously increased. Purpose: To discuss current concepts on the anti-diabetic impact of certain alkaloids, with special reference to their molecular targets throughout the insulin-signaling pathway. Methodology: Upon in-depth search in the SCOPUS and PUBMED databases, the literature on alkaloids with insulin secretion/sensitization properties was critically reviewed. Results: In-vitro and in-vivo evidence supports the effect of berberine, trigonelline, piperine, oxymatrine, vindoneline, evodiamine and neferine on insulin-signaling and related cascades in beta-cells, myocytes, adipocytes, hepatocytes and other cells. Associated receptors, kinases, hormones and cytokines, are affected in terms of gene transcription, protein expression, activity and/or phosphorylation. Pathophysiological processes associated with insulin resistance, beta-cell failure, oxidative stress and inflammation, as well as clinical phenotype are also influenced. Discussion: Growing evidence suggests the ability of specific alkaloids to intervene in the insulin-signal transduction pathway, reverse molecular defects resulting in insulin resistance and glucose intolerance and improve disease complications, in-vitro and in-vivo. Future indepth molecular studies are expected to elucidate their exact mechanism of action, while large clinical trials are urgently needed to assess their potential as anti-diabetic agents.

An isocratic reverse phase HPLC method were described to determined chrysophanol contain in cassia tora meal powder obtained during the split manufacturing process of cassia tora seed husk and germs which are used as a valuable cattle feed and poultry feed as they are quite rich in protein. The method involves methanol: water (90:10) with 0.05% Ortho-Phosphoric acid as solvent system and chromatogram detection was done on 254 nm using photodiode array detector. Chrysophanol were extracted using methanol, 70% methanol, acid hydrolysis and Oxidative hydrolysis by different concentration of the Hydrochloric acid and ferric chloride respectively. An average chrysophanol content was observed in cassia tora meal powder was 0.066 percent. In an efforts to develop an improved method for the determination of content of chrysophanol which is important marker compound in cassia tora meal and also improve method of an extraction methods. The solvents for extraction of chrysophanol from cassia tora were examined in order to increase the chrysophanol contents in cassia tora meal powder. It was found that 70% methanol, 20% HCL (v/v) and 3% FeCl3 (v/v) was capable of increasing the chrysophanol contain up to 0.099 percent. Keywords: HPLC, Chrysophanol, Extraction, Cassia tora meal powder

Abstract Context Previous epidemiologic studies of per- and polyfluoroalkyl substances (PFASs) and menopausal timing conducted in cross-sectional settings were limited by reverse causation because PFAS serum concentrations increase after menopause. Objectives To investigate associations between perfluoroalkyl substances and incident natural menopause. Design and Setting A prospective cohort of midlife women, the Study of Women’s Health Across the Nation, 1999-2017. Participants 1120 multiracial/ethnic premenopausal women aged 45-56 years. Methods Serum concentrations of perfluoroalkyls were quantified by high-performance liquid chromatography isotope dilution tandem mass spectrometry. Natural menopause was defined as the bleeding episode prior to at least 12 months of amenorrhea not due to surgery or hormone use. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Results Participants contributed 5466 person-years of follow-up, and 578 had incident natural menopause. Compared with the lowest tertile, women at the highest tertile of baseline serum concentrations had adjusted HR for natural menopause of 1.26 (95% CI: 1.02-1.57) for n-perfluorooctane sulfonic acid (n-PFOS) (Ptrend = .03), 1.27 (95% CI: 1.01-1.59) for branched-PFOS (Ptrend = .03), and 1.31 (95% CI: 1.04-1.65) for n-perfluorooctanoic acid (Ptrend = .01). Women were classified into four clusters based on their overall PFAS concentrations as mixtures: low, low–medium, medium–high, and high. Compared with the low cluster, the high cluster had a HR of 1.63 (95% CI: 1.08-2.45), which is equivalent to 2.0 years earlier median time to natural menopause. Conclusion This study suggests that select PFAS serum concentrations are associated with earlier natural menopause, a risk factor for adverse health outcomes in later life.

Background: The study of the natural killer (NK) immune compartment could provide important findings to help in the understanding of some of the pathogenetic mechanisms related to autoimmune thyroid diseases (Graves’ disease (GD) and Hashimoto’s thyroiditis (HT)). Within this context, it was suggested that alterations in NK cell cytotoxicity (NKCC) and NK production of cytokines might occur in subjects with GD and HT, whereas the normalization of NK functions could potentially contribute to the prevention of the onset or the progression of both diseases. Objective: Due to the hypothesis of alterations in NK in autoimmune thyroid diseases, we were interested to evaluate NKCC in GD and HT patients and to modulate NK function and secretory activity with cytokines and dehydroepiandrosterone sulfate (DHEAS) in an attempt to normalize NK cell defect. Design: We studied 13 patients with recent onset Graves’ disease, 11 patients with Hashimoto’s thyroiditis at first diagnosis and 15 age-matched healthy subjects. Methods: NK cells were concentrated at a density of 7.75 × 106 cells/ml by negative immunomagnetic cell separation and validated by FACScan as CD16 + /CD56 + cells. NK cells were incubated with interleukin-2 (IL-2) and interferon-β (IFN-β) and co-incubated with DHEAS at different molar concentrations for measuring NKCC and the secretory pattern of tumor necrosis factor-α (TNF-α) from NK cells. Results: Lower spontaneous, IL-2- and IFN-β-modulated NKCC was demonstrated in GD and HT patients compared with healthy subjects (P < 0.001). A decrease in spontaneous and IL-2-modulated TNF-α release from NK cells was also found in both groups of patients (P < 0.001). The co-incubation of NK cells with IL-2/IFN-β + DHEAS at different molar concentrations (from 10−8 to 10−5 M/ml/NK cells) promptly normalized NKCC and TNF-α secretion in GD and HT patients. Conclusions: A functional defect of a subpopulation of NK immune cells, involving both NKCC and the secretory activity, was demonstrated in newly-diagnosed GD and HT patients. This defect can be reversed by a dose-dependent treatment with DHEAS. The impairment of NK cell activity in autoimmune thyroid diseases could potentially determine a critical expansion of T/B-cell immune compartments leading to the generation of autoantibodies and to the pathogenesis of thyroid autoimmunity.

Introducción: La enfermedad renal crónica asociada a la obesidad (ERC-AO) es una enfermedad con aumento en la prevalencia en las últimas décadas. Se caracteriza por un exceso de desequilibrios hormonales adipocíticos (adipoquinas), desregulación del sistema de equilibrio energético y desequilibrios en la homeostasis metabólica. Propósito de la revisión: El objetivo de la revisión es delinear el papel de los diferentes mecanismos fisiopatológicos para el desarrollo de enfermedad renal funcional o anatómica en pacientes con obesidad. Buscamos reportes actualizados en donde se incluye los resultados de mejor supervivencia para los pacientes con ERC-AO. Recientes hallazgos: Actualmente sabemos la ERC-AO tiene un comportamiento pro inflamatorio crónico. La obesidad y sobrepeso se asocian alteraciones hemodinámicas, estructurales e histopatológicas en el riñón, así como alteraciones metabólicas y bioquímicas que predisponen a la enfermedad renal, aun cuando la función renal y las pruebas convencionales sean normales. Conclusiones: Clasificamos a la ERC-AO en Tipo 1: Obesidad y alteraciones funcionales potencialmente reversibles. Tipo 2: Obesidad y alteraciones estructurales histopatológicas potencialmente no reversibles (Incluye la Glomerulopatía asociada a obesidad y glomeruloesclerosis focal y segmentaria). Tipo 3: Obesidad en relacionada con enfermedades crónicas (Diabetes, Hipertensión, Hipertensión pulmonar. Insuficiencia Cardíaca). Tipo 4: Obesidad en el paciente con terapia sustitutiva de la función renal. Recibido: Agosto 03, 2022 Aceptado: Septiembre 30, 2022 Publicado: Septiembre 30, 2022 Editor: Dr. Franklin Mora Bravo. Introducción La obesidad es una enfermedad en crecimiento con un aumento en su prevalencia en las últimas décadas, asociándose a un elevada carga asistencial y económica para los sistemas sanitaros derivado de su relación con enfermedades cardiovasculares, endocrinas, psicológicas, renales entre otras [1, 2]. El incremento en las tasas de obesidad en distintos grupos etarios, desde niños hasta adultos jóvenes conlleva a asumir que en el futuro veremos más enfermedad renal relacionada con la obesidad (ERC-AO) en la población general, con implicaciones relevantes para los sistemas de atención [3]. Por ello el conocimiento y comprensión de esta interacción podría tener implicaciones en la prevención y tratamiento de las enfermedades renales. Dentro de la población general la obesidad se asocia a incremento en el riesgo de diversas condiciones patológicas, como la hipertensión arterial crónica (HTA), enfermedad renal crónica (ERC), artrosis, infecciones, síndrome de apnea hipopnea obstructiva del sueño (SAHOS) y diabetes mellitus (DM) entre otras [3]. No obstante, en el escenario de la ERC, la obesidad juega un rol dual y paralelo en el desarrollo de la enfermedad, tradicionalmente se ha denominado “paradoja de la obesidad”, donde por un lado actúa como un factor de riesgo modificable para el desarrollo de la enfermedad renal crónica (ERC) y por otro se ha asocia de manera consistente con mejores resultados de supervivencia en pacientes con enfermedad renal terminal [1]. Por lo anterior, en las próximas páginas describimos aspectos fisiopatológicos que involucran la obesidad en el desarrollo de la ERC. Definición y epidemiología La obesidad es una condición que se caracteriza por la acumulación anormal o excesiva de tejido adiposo con consecuencias patológicas adversas e incremento del riesgo cardiovascular [4]. Utilizando para su definición y diagnostico un indicador simple como es la relación entre el peso y la talla denominado índice de masa corporal (IMC), se calcula dividiendo el peso de una persona en kilos por el cuadrado de su talla en metros (kg/m2). Un IMC entre 18.5 y 25 kg/m2 es considerado por la Organización Mundial de la Salud (OMS) como peso normal, un IMC entre 25 y 30 kg/m2 como sobrepeso y un IMC > 30 kg/m2, como obesidad [5-7]. Además, la obesidad puede ser clasificada en tres niveles de severidad: clase I (IMC 30.0 – 34.9), clase II (IMC 35.0 – 39.9) y clase III (IMC > 40) [8]. Durante las últimas tres décadas, la prevalencia de adultos con sobrepeso y obesidad (IMC ≥ 25 kg/m2) en todo el mundo ha aumentado sustancialmente, convirtiendo a la obesidad en una epidemia y se prevé que su prevalencia crezca un 40% en la próxima década [6]. Actualmente, el problema de obesidad se ha visto en mayor aumento debido al incremento en la afectación en niños, lo que ocasiona una mayor prevalencia de patologías a edad temprana. En 2016, según las estimaciones de la OMS unos 41 millones de niños menores de cinco años tenían sobrepeso o eran obesos [7]. Esto afectando a todos los países, independiente de su nivel de ingresos [7]. La prevalencia del sobrepeso y la obesidad en niños y adolescentes (de 5 a 19 años) ha aumentado de forma espectacular, del 4% en 1975 a más del 18% en 2016. Este aumento ha sido similar en ambos sexos: un 18% de niñas y un 19% de niños con sobrepeso en 2016. Mientras que en 1975 había menos de un 1% de niños y adolescentes de 5 a 19 años con obesidad, en 2016 eran 124 millones (un 6% de las niñas y un 8% de los niños) [7]. La creciente prevalencia de la obesidad tiene implicaciones para las enfermedades cardiovasculares (ECV) y también para la ERC. Un IMC alto es uno de los factores de riesgo más fuertes para la ERC de nueva aparición [6]. Epidemiología de la enfermedad renal crónica asociada a obesidad (ERC-AO) La enfermedad renal crónica (ERC) es una condición de interés en salud pública, asociada a una elevada morbilidad y mortalidad a nivel mundial. Las guías KDIGO (Kidney Disease: Improving Global Outcomes), definen la ERC como la presencia de alteraciones en la estructura o función renal durante al menos tres meses y con implicaciones para la salud [9, 10]. Los principales elementos clasificatorios para definir la presencia de ERC son la tasa de filtración glomerular (TFG) estimada (G1 a G5) utilizando como umbral definitorio una TFG 60 ml/min/1,73m2 y la tasa de excreción de albúmina en orina (A1 a A3) según el cociente albúmina/creatinina en una muestra aislada de orina sea < 30, 30-300 o > 300 mg/g, respectivamente [9, 10]. Si bien inicialmente existía cierta controversia sobre el uso de la TFG para el diagnóstico de la ERC en fases iniciales, trabajos recientes han puesto en evidencia que tanto una TFG< 60 ml/min/1.73 m2 como un cociente albúmina/creatinina (CAC) ≥ 1.1 mg/mmol (10 mg/g) son predictores independientes del riesgo de mortalidad e insuficiencia renal terminal (IRT) en población general [11, 12]. En consecuencia, debido a estas categorías podemos determinar el pronóstico de cada paciente. Los datos globales sugieren que la prevalencia de la ERC se encuentra entre el 10 y el 16 %, pero la información sobre la prevalencia de la población por categoría de TFG y ACR es escasa [13]. La ERC es una afección asociada a una elevada carga de morbilidad, mortalidad y enfermedad cardiovascular (ECV). A medida que disminuye la función renal, surgen trastornos metabólicos y hemodinámicos que aumentan las tasas de hospitalización, ECV y muerte [4]. El conjunto de factores de riesgo conocidos para la progresión de la ERC es relativamente pequeño, y las terapias y estrategias efectivas para retrasar la progresión de la ERC son limitadas [14]. Por lo cual resulta necesario conocer y entender los diferentes factores de riesgo y su impacto en el daño renal, en aras de lograr minimizar la progresión del mismo, sobre todo en aquellos en los cuales se puede realizar intervenciones activas, evaluables, controlables y con seguimiento continuo como es la obesidad. A la fecha existe suficiente evidencia para asociar la obesidad con el desarrollo y progresión de la enfermedad renal crónica. Los datos granulares sobre la prevalencia de la obesidad en personas con ERC son limitados pero consistentes en todo el espectro de la enfermedad renal. En la Encuesta Nacional de Examen de Salud y Nutrición de 2011–2014, el 44.1 % de los pacientes con ERC en los Estados Unidos también tenían obesidad (21.9 % con obesidad de clase 1 y 11.1 % con clase 2 y obesidad clase 3, habiéndose incrementado el porcentaje global un 5% en los últimos 12 años [15]. La glomeruloesclerosis focal y segmentaria (GEFS) es el tipo de glomerulonefritis que se asocia con mayor frecuencia a la obesidad [16]. La enfermedad glomerular habitualmente asociada a la obesidad se denomina glomerulopatía relacionada con la obesidad (GRO). Esta condición suele presentarse con síndrome nefrótico y pérdida progresiva de la función renal. Con la epidemia mundial de obesidad, se produjo un aumento progresivo de la GRO del 0.2% entre 1986 y 1990 al 2% entre 1996 y 2000, y se ha convertido en un tema emergente en el ámbito de la nefrología [15]. Etiología y patogénesis de la ERC-AO La obesidad se caracteriza por un exceso de desequilibrios hormonales adipocíticos (adipoquinas), desregulación del sistema de equilibrio energético y desequilibrios en la homeostasis metabólica [12]. Hay dos tipos de tejido adiposo presentes en los humanos: tejido adiposo blanco (WAT) y tejido adiposo marrón (BAT) [17-19]. El depósito de grasa ectópica primariamente ocurre en lugares donde no se almacena fisiológicamente, como el hígado, el páncreas, el corazón y el músculo esquelético; secundariamente hay un cambio en la distribución del tejido adiposo visceral con almacenamiento de tejido adiposo en los espacios intraperitoneal y retroperitoneal; luego se presenta la desregulación inflamatoria y de adipoquinas; y por último la resistencia a la insulina [20]. Tejido adiposo blanco (WAT) El tejido adiposo blanco (WAT) se caracteriza por ser un tejido blanco o amarillo con menor vascularización e inervación que el tejido marrón. Las células grasas tienen un tamaño que oscila entre 20 y 200 µm y contienen una única vacuola lipídica (uniloculares). En dicha vacuola se almacenan lípidos para su uso cuando hay demanda energética. De la totalidad de los lípidos que abarca la vacuola lipídica del adipocito blanco, del 90 al 99% son triacilgliceroles. El tejido adiposo blanco genera una gran cantidad de adipocinas y lipocinas. Las adipocinas son péptidos que actúan como hormonas o mensajeros que regulan el metabolismo. El tejido adiposo blanco se localiza en el tejido omental, mesentérico, retroperitoneal, perirrenal, gonadal y pericárdico [19]. Este tejido al igual que el tejido adiposo de otros sitios, está compuesto por una variedad de células que incluyen macrófagos, neutrófilos, células T CD4 y CD8, células B, neutrófilos, mastocitos, células T reguladoras y células T asesinas naturales (NK) [21, 22]. El tejido adiposo es responsable de la secreción de muchas moléculas de señalización, incluidas adipocinas, hormonas, citocinas y factores de crecimiento, como leptina, adiponectina, resistina, factor de necrosis tumoral-α (TNF-α), interleucina 6 (IL-6), monocito, proteína quimioatrayente-1 (MCP-1), factor de crecimiento transformante-β (TGF-β) y angiotensina II [23]. Tejido adiposo marrón o pardo (BAT) La coloración marrón del tejido adiposo se debe a que está más vascularizado y tiene un alto contenido de mitocondrias, las células grasas que componen el tejido adiposo pardo son multiloculares o tienen varias vacuolas lipídicas. Estas células tienen forma poligonal y miden de 15 a 50 µm. A diferencia del tejido adiposo blanco, el tejido marrón no tiene la función de almacenar energía, sino que la disipa a través de la termogénesis. Para lograr la regulación de la temperatura corporal, el tejido adiposo pardo se localiza en sitios superficiales y profundos [18]. Clasificación de la ERC-AO Se ha establecido que la obesidad es una enfermedad con un comportamiento pro inflamatorio crónico con múltiples comorbilidades asociadas [19]. El tejido adiposo como se describió previamente funciona como un órgano con actividad endocrina y esta infiltrado por diferentes poblaciones celulares que incluyen macrófagos y otras células con actividad inmune como linfocitos T, B y células dendríticas [19]. La mayor parte de la grasa corporal total, se considera como un sistema de órganos endocrinos, la perturbación de este tejido tiene como resultado una respuesta patológica al balance calórico positivo en individuos susceptibles que directa e indirectamente contribuye a la enfermedad cardiovascular y metabólica, se tiene conocimiento de tres principales mecanismos de disfunción del tejido adiposo “adiposopatía” [20]. Estos mecanismos incluyen alteraciones hemodinámicas, metabólicas e inflamatorias, lo que es la base de la clasificación de la ERC-AO propuesta en esta revisión (Tabla 1). ERC-AO tipo 1 La obesidad produce un daño renal de forma directa a través de alteraciones hemodinámicas, inflamatorias, y desregulación de factores de crecimiento y adipocitoquinas, además de aumento de leptina y disminución de adiponectina, aun cuando la función renal y las pruebas convencionales sean normales [16]. La obesidad desencadena una serie de eventos, que incluyen resistencia a la insulina, intolerancia a la glucosa, hiperlipidemia, aterosclerosis e hipertensión, todos los cuales están asociados con un mayor riesgo cardiovascular [4, 16] (Figura 1). La obesidad conduce a un incremento en la reabsorción tubular de sodio, alterando la natriuresis y provocando una expansión de volumen extracelular debido a la activación del sistema nervioso simpático (SNS) y el sistema renina-angiotensina-aldosterona (SRAA)(16). El aumento en la reabsorción tubular de sodio y la consiguiente expansión de volumen extracelular es un evento central en el desarrollo de HTA en la obesidad [4, 16]. Algunos estudios sugieren que se produce un aumento de la reabsorción de sodio en algunos segmentos además del túbulo proximal, posiblemente en el asa de Henle. Además, hay un aumento del flujo sanguíneo renal, la tasa de filtración glomerular (TFG) y la fracción de filtración [16]. La hiperfiltración glomerular, asociada con el aumento de la presión arterial y otras alteraciones metabólicas como la resistencia a la insulina y la DM, finalmente resultan en daño renal y disminución del filtrado glomerular [16]. Por otro lado, la activación del SNS también contribuye a la hipertensión relacionada con la obesidad [4]. Hay evidencia de que la denervación renal reduce la retención de sodio y la hipertensión en la obesidad, lo que sugiere que la activación del SNS inducida por la obesidad aumenta la presión arterial principalmente debido al estímulo de retención de sodio, más que a la vasoconstricción [16]. Los mecanismos que conducen a la activación del SNS en la obesidad aún no se conocen por completo, pero se han propuesto varios factores como desencadenantes de este estímulo, entre ellos la hiperinsulinemia, la hiperleptinemia, el aumento de los niveles de ácidos grasos, los niveles de angiotensina II y las alteraciones del reflejo barorreceptor. El aumento de los niveles de leptina está asociado a la activación del SNS y su efecto sobre el aumento de los niveles de presión arterial incluye también la inhibición de la síntesis de óxido nítrico (potente vasodilatador) [16, 24, 25].También se ha descrito un aumento de la producción de endotelina-1 en sujetos obesos, lo que contribuye aún más a la elevación de los niveles de presión arterial y, en consecuencia, a la disfunción renal. Estudios recientes han demostrado que la endotelina-1 está aumentada en pacientes con hipertensión intradiálisis, lo que sugiere que esta sustancia juega un papel clave en la génesis de la hipertensión en pacientes con ERC y posiblemente esté asociada con la hipertensión en pacientes obesos [16, 25]. Por lo anterior, las alteraciones hemodinámicas en los pacientes con obesidad conllevan a progresión de la ERC e incremento del riesgo cardiovascular derivado del desarrollo de enfermedades adicionales como la HTA, potencialmente estos cambios son reversibles con el control de la obesidad. ERC-AO Tipo 2 Mantener el estado de obesidad más allá de los efectos renales funcionales produce cambios estructurales irreversibles a nivel glomerular [25]. El estudio de pacientes con ERC y obesidad ha permitido identificar la presencia de enfermedad glomerular asociada a la obesidad, denominada glomerulopatía relacionada con la obesidad (GRO). En esta condición la hipertrofia glomerular parece ser la lesión inicial que estimula el borramiento de los podocitos y desencadena la respuesta inflamatoria local [25, 26]. Es relevante mencionar que las señales profibrogénicas inducen la formación de depósitos en la matriz extracelular de las nefronas, que conduce al engrosamiento de la membrana basal glomeruloesclerosis y fibrosis tubulointersticial [26]. Dentro del curso patogénico de la enfermedad la expansión de la superficie glomerular conduce a que los podocitos sean incapaces de cubrirla, esto lleva a disfunción y borramiento de los mismos, generando ruptura de la barrera de filtración glomerular con sobrecarga de las células restantes, lo que finalmente conduce a hiperfiltración y proteinuria [25, 26]. No obstante, no todos los pacientes con obesidad o IMC aumentado desarrollan ERC, lo cual sugiere que el incremento del IMC por sí solo no genera aumento en la incidencia o progresión de la ERC, ameritando alteraciones metabólicas adicionales. En los siguientes apartados se describen algunas de estas vías fisiopatológicas comunes a todos los tipos de ERC-AO. ERC-AO Tipo 3 La obesidad produce daño renal de forma secundaria ya que aumenta el riesgo de diabetes mellitus, hipertensión y daño cardiovascular, estas patologías causan enfermedad renal diabética (ERD), nefroangioesclerosis, y glomerulopatía asociada a hipertensión pulmonar e insuficiencia cardíaca. La mortalidad no solo se ve afectada por la presencia de la obesidad sino por la presencia de diabetes tipo 2, hipertensión arterial, hipertensión pulmonar e insuficiencia cardíaca. Los peores resultados en supervivencia lo padecen los pacientes con falla cardíaca, obesidad e insuficiencia renal. ERC-AO Tipo 4 En pacientes en hemodiálisis los niveles más elevados de adiponectina se asocian paradójicamente con tres veces más riesgo de muerte [24]. La obesidad se asocia a niveles muy bajos adiponectina por lo que la obesidad en el grupo poblacional que se realiza hemodiálisis es un fuerte factor protector con mejores resultados de supervivencia a 3 años comparados con pacientes con índice de masa corporal normal o baja. Mecanismos fisiopatológicos comunes en la ERC-AO Lipotoxicidad derivada del tejido adiposo En pacientes obesos el exceso de energía conduce a un microambiente sometido a estrés crónico, lo cual resulta en hipertrofia del tejido adiposo hasta que los adipocitos alcanzan su límite de crecimiento [25]. En ese momento, el exceso de especies toxicas lipídicas se acumula ectópicamente en diferentes órganos, induciendo un efecto nocivo conocido como lipotoxicidad; especialmente a nivel renal [27]. La lipotoxicidad se asocia a cambios estructurales y funcionales de las células mesangiales, podocitos y células tubulares proximales [28]. En los podocitos, esto interferiría con la vía de la insulina, crítica para la supervivencia y el mantenimiento de la estructura de los podocitos, lo que conduciría a la apoptosis de los podocitos e induciría una respuesta hipertrófica compensatoria en los podocitos restantes [25]. En el riñón, los depósitos de lípidos ectópicos contribuyen tanto a la inflamación local como al estrés oxidativo [27]. En modelos de ERD, la dislipidemia puede favorecer la acumulación de lípidos ectópicos e intermediarios lipídicos, no solo en el riñón sino también en tejidos extrarrenales como hígado, páncreas y corazón [27]. La acumulación de lípidos en el parénquima renal, genera daño en varias poblaciones celulares, incluídos podocitos, células epiteliales tubulares proximales y el tejido tubulointersticial a través de distintos mecanismos descritos en las siguientes apartados, pudiendo general compromiso a largo plazo de la función renal [27]. El tejido adiposo es una fuente importante de producción de diferentes factores proteicos activos, conocidos como adipocitocinas, las cuales participan en diferentes procesos metabólicos. Alteraciones en la secreción y señalización de moléculas derivadas del tejido adiposo durante la obesidad en gran medida puede mediar en la patogenia de los trastornos metabólicos [25]. A continuaciones se describe el rol de las adipocinas en la patogenia de la ERC y obesidad. Adiponectina La adiponectina es una proteína secretada principalmente por los adipocitos WAT, las principales funciones biológicas de la adiponectina incluyen una mayor biosíntesis de ácidos grasos y la inhibición de la gluconeogénesis hepática [17]. Es probablemente la adipocina secretada más abundantemente, forma alrededor del 0.05 % de las proteínas séricas y mide de 3 a 30 mg/ml en humanos, para su activación utiliza dos isoformas del receptor (AdipoR1 y AdipoR2) son receptores de siete transmembranas y tienen una homología del 66.7 % en su estructura [17]. Sin embargo, AdipoR1 y AdipoR2 son estructural y funcionalmente distintos de los receptores acoplados a proteína G porque su terminal N es intracelular, mientras que el terminal C es extracelular [29, 30]. La señalización de adiponectina se basa principalmente en interacciones de tipo receptor-ligando, en las que la adiponectina se une a sus receptores afines e inicia la activación de varias cascadas de señalización intracelular a través de las vías AMPK, mTOR, NF-κB, STAT3 y JNK [17]. La adiponectina inicia la activación de la señalización de AMPK mediada por la proteína adaptadora APPL1, que se une al dominio intracelular de AdipoR. Eso produce la activación de la biosíntesis de moléculas, otras proteínas reguladoras e importantes factores de transcripción. AMPK es un regulador que participa principalmente en la proliferación celular [17]. Hay dos tipos de macrófagos, M1 participan en la estimulación de los factores pro inflamatorios e induce la resistencia a la insulina y M2 bloquean una respuesta inflamatoria y promueve el metabolismo oxidativo; En los macrófagos, la adiponectina promueve la diferenciación celular de monocitos a macrófagos M2 y suprime su diferenciación a macrófagos M1, lo que muestra efectos pro inflamatorios y antiinflamatorios. Además, también activa los factores antiinflamatorios IL-10 pero reduce las citoquinas pro inflamatorias como IFN-γ, IL-6 y TNF-α en los macrófagos humanos [17]. Los pacientes con ERC muestran niveles elevados de proteína C reactiva (PCR), IL-6 y TNF-α y tienen una activación aberrante de receptor tipo toll (TLR)-4 [25]; en un estudio realizado en el año 2005 en 29 pacientes con ERC no diabéticos en etapa 5 y 14 controles sanos, se identificó que los pacientes con ERC tenían una expresión elevada del gen y la proteína TLR4, la estimulación de TLR-4 in vitro indujo la activación de TNF-α y NF-κB en células C2C12. Esto sugiere indirectamente que la activación de TLR-4 podría promover la inflamación muscular de los pacientes con ERC [31]. Los niveles de adiponectina se consideran predictivos de ERC, dado que estos se encuentran aumentados en pacientes con etapa pre diálisis [17, 29, 32]. Adicionalmente, en un estudio prospectivo realizado en el año 2008 en pacientes con ERC primaria no diabética identificó niveles elevados de adiponectina como un predictor novedoso de progresión de la ERC en hombres [33]. En estudios realizados en animales (ratones) muestran que la deficiencia de adiponectina se relaciona con varias alteraciones histológicas, incluida la fusión segmentaria procesos podocitarios, albuminuria y aumento del estrés oxidativo en los riñones [34]. Por otro lado, en pacientes obesos la producción de adiponectina se encuentra disminuida por lo que se cree que puede generar una función protectora sobre el riñón [29]. No obstante, paradójicamente, algunos estudios muestran que los pacientes con ERC y enfermedad renal crónica en diálisis (ERCT) tienen altos niveles de adipocinas, las explicaciones a esta situación son controversiales, se ha planteado podrían corresponder a un mecanismo compensatorio, otras consideraciones sugieren una disminución de la sensibilidad a la adiponectina o una reducción en el aclaramiento de la misma [35]. Leptina En pacientes con ERC independiente de la presencia de obesidad o no, se asocian a niveles elevados de leptina sérica. La leptina es una proteína de 167 aminoácidos, con una masa molecular de aproximadamente 16 kDa que está codificada por el gen LEP [23] secretada principalmente por los adipocitos, es una adipocina pleiotrópica. La leptina circulante llega a los órganos diana, donde se une a receptores específicos (conocidos como ObR, LR o LEPR), se conocen cinco isoformas del receptor de leptina en humanos (ObRa, ObRb, ObRc, ObRd y ObRe), de estas solo la isoforma ObRb (isoforma larga) se considera un receptor completamente activo, ya que es capaz de transducir completamente una señal de activación en la célula. Esta isoforma se encuentra altamente expresada en el sistema nervioso central (SNC), especialmente en el hipotálamo, donde participa en la regulación de la actividad secretora de este órgano. Los efectos de la leptina están mediados por cinco vías principales de señalización. Estas vías incluyen las vías de señalización JAK-STAT, PI3K, MAPK, AMPK y mTOR [23]. Por esta razón la principal función fisiológica de la leptina es transmitir información al hipotálamo sobre la cantidad de energía almacenada, como la masa de tejido adiposo, e influir en el gasto de energía al reducir el apetito. Regula el metabolismo energético, tiene efecto sobre la ingesta de alimentos, procesos de coagulación, angiogénesis, funciones relacionadas con la insulina y la remodelación vascular, además funciona como un pro inflamatorio molecular [36]. La leptina tiene efectos sobre el apetito y se ha demostrado que la hiperleptinemia contribuye a la hipertensión asociada a la obesidad por sobre activación del sistema nervioso simpático [37]. En cuanto al curso de la ERC, la leptina puede modular diferentes vías de señalización en el riñón, debido a que las células endoteliales glomerulares y mesangiales expresan abundantes receptores de leptina [25]. La leptina inducirá un incremento en la expresión de genes profibróticos, como TGF-β1 y citocinas pro inflamatorias [25]. El aumento en la expresión de TGF-β1, también contribuirá al desarrollarlo de la fibrosis renal, al unirse a receptores específicos a nivel renal, estimulara la expresión de factores profibróticos en un ciclo de retroalimentación positiva. Además, TGF-β1 es un potente iniciador de proliferación de células mesangiales renales [25]. Debido a su tamaño relativamente pequeño, la leptina atraviesa libremente el filtro glomerular de los riñones y luego se reabsorbe en la parte proximal de los túbulos contorneados [23]. Por lo que el estado elevado de leptina puede indicar una función renal deficiente [36]. Promueve la inflamación y trastorno de los lípidos, que contribuyen al riesgo de ERC [36]; se considera como “toxina urémica”, estando implicada tanto en la progresión de la enfermedad renal a través de efectos pro-hipertensivos y profibróticos, como en el desarrollo de complicaciones relacionadas con la ERC (inflamación crónica, pérdida de proteínas) [38]. Como se mencionó previamente, la leptina estimula la proliferación de células endoteliales glomerulares renales y aumenta la expresión de TGF-β1, un mediador clave de la hidrogénesis en estas células, el aumento de los niveles de leptina también contribuye al aumento de la expresión de colágeno tipo IV en el riñón, induce la proliferación de células mesangiales glomerulares mediante la activación de la vía PI3K, la hipertrofia de las células mesangiales aumenta la cantidad de proteína filtrada y albúmina que llega a las células del túbulo proximal y, como resultado, activa las vías inflamatorias y la fibrosis [23]. Puede presentarse un aumento en la síntesis del receptor TGFβ-1 secretado por las células endoteliales, este actúa de manera parácrina sobre el mesangio uniéndose a su receptor y activando la síntesis de proteínas de la matriz extracelular (ECM), incluyendo colágeno, fibronectina, tenazina y proteoglicanos; consiguientemente, un aumento en el nivel de TGFβ-1 conduce a la acumulación de MEC y, en consecuencia, a fibrosis glomerular y glomeruloesclerosis. En los podocitos, la leptina contribuye a la disminución de la expresión de las proteínas responsables de la filtración glomerular adecuada, incluidas la podocina, la nefrina, la podoplanina y la podocalixina. En las células del túbulo contorneado proximal (PTC), la leptina reduce la actividad metabólica de las células al activar la vía de señalización de mTOR [23]. Por otro lado, la leptina inhibe el apetito y aumenta el gasto de energía conduciendo a anorexia y desnutrición en pacientes con ERC, particularmente en casos de hemodiálisis de mantenimiento [36]. Por ende, una elevación de la leptina no solo nos indicaría daño renal, sino que además nos indica mayor progresión de complicaciones secundarias [39]. La obesidad aumenta la carga sobre los riñones y es un factor de riesgo de lesión renal, además de contribuir en los trastornos metabólicos asociados. Por lo que, teniendo en cuenta los efectos inhibitorios de la leptina sobre la obesidad, se puede considerar que puede proteger contra la lesión renal [39, 40]. Un estudio experimental publicado en el año 2017 demostró que la leptina disminuyó la ingesta calórica y los niveles de glucosa en ratas diabéticas [41], ese mismo año se publicó un estudio retrospectivo donde demostraron que la metreleptina, una metionil leptina humana recombinante, reduce el peso corporal y la dosis diaria de insulina en la diabetes mellitus tipo 1 [42]. La metreleptina ejerce efectos terapéuticos en la lipodistrofia [43], lo que indica que es probable que la leptina se aplique en los trastornos metabólicos [36]. Otras adipocinas Las principales adipocinas corresponden a la adiponectina y leptina como se ha descrito previamente. Además de estas, se distinguen la actividad de la visfatina y resistina, las cuales muestran propiedades pro-inflamatorias y efectos aterogénicos [25]. La visfatina estimula la expresión de TGF-β1, inhibidor del activador del plasminógeno-1 (PAI-1) y colágeno tipo I, los cuales han demostrado un rol importante como agentes profibróticos. Por otro lado, la resistina estimula la producción de las moléculas de adhesión como la molécula de adhesión intracelular 1 (ICAM-1) y la proteína de adhesión celular vascular 1 (VCAM-1) y promueve la activación del sistema renal simpático. Los niveles de estas adipocinas están marcadamente elevados en la obesidad y ERC correlacionándose con parámetros proinflamatorios y disminución de la tasa de filtración glomerular (TFG) [25, 37]. Durante el curso de la obesidad se presenta una sobre activación del SRAA, el tejido adiposo también estaría involucrado en la producción o estimulación de algunos de los componentes del RAS. Por ello la sobre estimulación del SRAA en obesos, asociado a la glomerulomegalia y desregulación de la reabsorción de sodio/glucosa, generalmente conlleva a hipertensión glomerular e hiperfiltración [25]. Otra adipocina a considerar, es la actividad de la adipocina proinflamatoria lipocalina 2 (LCN2), también denominada lipocalina asociada con la gelatinasa de neutrófilo (NGAL), estudiada como biomarcador funcional tanto para la enfermedad renal aguda como ERC(25). LCN2 es conocido por su papel en la respuesta inmune innata a través de su unión a sideróforos derivados de una infección bacteriana. Sin embargo, LCN2 no es secretada únicamente por neutrófilos sino también por otros tejidos como hígado, pulmones y de interés para este artículo, a nivel renal [25]. Se han informado niveles elevados de LCN2 en suero y orina en la lesión renal, debido a una expresión aumentada de LCN2 en el túbulo distal renal y una reabsorción alterada en el túbulo proximal [44]. El tejido adiposo, también puede producir factores angiogénicos como el factor de crecimiento del endotelio vascular (VEGF). Este elemento podría inducir la formación de novo de capilares glomerulares en gran parte defectuosos dentro del riñón, lo que contribuye a la hipertrofia glomerular característica de GRO [25] (Figura 2). Conclusiones La obesidad y el sobrepeso se asocian a alteraciones hemodinámicas, estructurales e histopatológicas en el riñón, así como alteraciones metabólicas y bioquímicas que predisponen a la enfermedad renal, aun cuando la función renal y las pruebas convencionales sean normales. Por lo tanto, los efectos renales de la obesidad son estructurales y funcionales. Hay varios mecanismos actualmente descritos que involucran a la obesidad como generador de alteraciones renales. Teniendo en cuenta las bases fisiopatológicas, proponemos una clasificación de la ERC-AO basadas en 4 tipos. Abreviaturas ERC: enfermedad renal crónica. ERC-AO: enfermedad renal crónica-asociada a enfermedad. VEGF: factor de crecimiento del endotelio vascular. OR: Odds ratio. Información suplementaria Materiales suplementarios no han sido declarados. Agradecimientos No aplica. Contribuciones de los autores Jorge Rico-Fontalvo: Conceptualización, Curación de datos, Análisis formal, Adquisición de fondos, Investigación, Metodología, Administración de proyecto, Recursos, Software, Escritura – borrador original. Rodrigo Daza-Arnedo: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Tomás Rodríguez-Yanez: Metodología, validación, supervisión, redacción: Revisión y edición. Washington Osorio: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Beatriz Suarez-Romero: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Oscar Soto: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Juan Montejo-Hernandez: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. María Cardona-Blanco: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Juan Camilo Gutiérrez: Conceptualización, Supervisión, Validación, Visualización, Redacción: revisión y edición. Todos los autores leyeron y aprobaron la versión final del manuscrito. Financiamiento Los autores proveyeron los gastos de la investigación. Disponibilidad de datos o materiales Los conjuntos de datos generados y analizados durante el estudio actual no están disponibles públicamente debido a la confidencialidad de los participantes, pero están disponibles a través del autor correspondiente a pedido académico razonable. Declaraciones Aprobación del comité de ética y consentimiento para participar No aplica para revisiones narrativas. Consentimiento para publicación No aplica cuando no se publican imágenes o fotografías del examen físico o radiografías/tomografías/resonancias de pacientes. Conflictos de interés Los autores reportan no tener conflictos de interés. 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AbstractThe protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to the current vaccination or natural infection is a global concern. We aimed to investigate the rate of SARS-CoV-2 infection and its clinical features among infection-naïve, infected, vaccinated, and post-infection-vaccinated individuals. A cohort was designed among icddr,b staff registered for COVID-19 testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). Reinfection cases were confirmed by whole-genome sequencing. From 19 March 2020 to 31 March 2021, 1644 (mean age, 38.4 years and 57% male) participants were enrolled; where 1080 (65.7%) were tested negative and added to the negative cohort. The positive cohort included 750 positive patients (564 from baseline and 186 from negative cohort follow-up), of whom 27.6% were hospitalized and 2.5% died. Among hospitalized patients, 45.9% had severe to critical disease and 42.5% required oxygen support. Hypertension and diabetes mellitus were found significantly higher among the hospitalised patients compared to out-patients; risk ratio 1.3 and 1.6 respectively. The risk of infection among positive cohort was 80.2% lower than negative cohort (95% CI 72.6–85.7%; p < 0.001). Genome sequences showed that genetically distinct SARS-CoV-2 strains were responsible for reinfections. Naturally infected populations were less likely to be reinfected by SARS-CoV-2 than the infection-naïve and vaccinated individuals. Although, reinfected individuals did not suffer severe disease, a remarkable proportion of naturally infected or vaccinated individuals were (re)-infected by the emerging variants.

Abstract Aims The aging heart naturally incurs a progressive decline in function and perfusion that available treatments cannot halt. However, some exceptional individuals maintain good health until the very late stage of their life due to favourable gene-environment interaction. We have previously shown that carriers of a longevity-associated variant (LAV) of the BPIFB4 gene enjoy prolonged health spans and lesser cardiovascular complications. Moreover, supplementation of LAV-BPIFB4 via an adeno-associated viral vector improves cardiovascular performance in limb ischemia, atherosclerosis, and diabetes models. Here, we asked if the LAV-BPIFB4 gene could address the unmet therapeutic need to delay the heart’s spontaneous aging. Methods and Results Immunohistological studies showed a remarkable reduction in vessel coverage by pericytes in failing hearts explanted from elderly patients. This defect was attenuated in patients carrying the homozygous LAV-BPIFB4 genotype. Moreover, pericytes isolated from older hearts showed low levels of BPIFB4, depressed pro-angiogenic activity, and loss of ribosome biogenesis. LAV-BPIFB4 supplementation restored pericyte function and pericyte-endothelial cell interactions through a mechanism involving the nucleolar protein nucleolin. Conversely, BPIFB4 silencing in normal pericytes mimed the heart failure pericytes. Finally, gene therapy with LAV-BPIFB4 prevented cardiac deterioration in middle-aged mice and rescued cardiac function and myocardial perfusion in older mice by improving microvasculature density and pericyte coverage. Conclusions We report the success of the LAV-BPIFB4 gene/protein in improving homeostatic processes in the heart’s aging. These findings open to using LAV-BPIFB4 to reverse the decline of heart performance in older people.

BackgroundThyroid hormones (TH), T4 and T3, mediate pro-mitogenic effects in cancer cells through binding the membrane receptor αvβ3 integrin. The deaminated analogue tetrac effectively blocks TH binding to this receptor and prevents their action. While computational data on TH binding to the αvβ3 integrin was published, a comprehensive analysis of additional TH metabolites is lacking.MethodsIn-silico docking of 26 TH metabolites, including the biologically active thyroid hormones (T3 and T4) and an array of sulfated, deiodinated, deaminated or decarboxylated metabolites, to the αvβ3 receptor binding pocket was performed using DOCK6, based on the three-dimensional representation of the crystallographic structure of the integrin. As the TH binding site upon the integrin is at close proximity to the well-defined RGD binding site, linear and cyclic RGD were included as a reference. Binding energy was calculated for each receptor-ligand complex using Grid score and Amber score with distance movable region protocol.ResultsAll TH molecules demonstrated negative free energy, suggesting affinity to the αvβ3 integrin. Notably, based on both Grid and Amber scores sulfated forms of 3,3’ T2 (3,3’ T2S) and T4 (T4S) demonstrated the highest binding affinity to the integrin, compared to both cyclic RGD and an array of examined TH metabolites. The major thyroid hormones, T3 and T4, showed high affinity to the integrin, which was superior to that of linear RGD. For all hormone metabolites, decarboxylation led to decreased affinity. This corresponds with the observation that the carboxylic group mediates binding to the integrin pocket via divalent cations at the metal-ion-dependent adhesion (MIDAS) motif site. A similar reduced affinity was documented for deaminated forms of T3 (triac) and T4 (tetrac). Lastly, the reverse forms of T3, T3S, and T3AM showed higher Amber scores relative to their native form, indicating that iodination at position 5 is associated with increased binding affinity compared to position 5’.SummaryThree-dimensional docking of various TH metabolites uncovered a structural basis for a differential computational free energy to the αvβ3 integrin. These findings may suggest that naturally occurring endogenous TH metabolites may impact integrin-mediate intracellular pathways in physiology and cancer.

AbstractCognitive impairment is considered as a typical feature of neurodegenerative diseases in diabetes mellitus (DM). However, the exact link between cognitive dysfunction and diabetes mellitus is still vague. This study aims to investigate some of the mechanisms underlying cognitive impairment that associates diabetes mellitus and insulin resistance. We investigated the role of resveratrol as well on cognitive function in experimentally induced type 2 diabetes highlighting on its influence on the expression of brain miRNA 21. Resveratrol is a naturally occurring, biologically active compound that has numerous significant impacts on the body. Type 2 diabetes mellitus was induced by high fat diet followed a single dose of streptozotocin. Diabetic rats were treated with resveratrol for four weeks. Rats were sacrificed after neurobehavioral testing. Hippocampal tissues were used to assess expression of miRNA 21, GSK and oxidative stress markers. Serum samples were obtained to determine glucose levels, lipid profile and insulin levels. Hippocampal and serum AGEs were measured as well and HOMA IR was calculated. We detected memory impairment and disturbed insulin signaling in diabetic rats. These derangements were reversed by resveratrol treatment partially due to increased expression of miRNA-21. Our study pins the role of miRNA-21 in modulating brain insulin signaling and hence alleviating cognitive dysfunction accompanying diabetes mellitus.

SARS-CoV-2 is closely related to the original SARS-CoV. It is thought to have animal based origin from Bats(Betacoronavirus) in subgenus (Sarbecoronavirus) together with two bat-derived strains The virus is mainly spread between people during physical contact, often through small droplets produced during coughing, sneezing, even talking to patient or infected people. It is primarily spread during close contact and via small droplets produced when infected people cough, sneeze or talk with close contact being within 1–3 m (3 ft 3 in–9 ft 10 in). Those infected with the virus may be asymptomatic (Appearance of No symptoms) or develop flu-like symptom which include fever, cough, fatigue, and shortness of breath. The exposure time to initial symptom is day five (5 days). Majority of cases result in mild symptoms, some progress to viral pneumonia and multiple organ failure. Two medicinal plants may be used for the treatment of SARS-CoV-2, the two medicinal plants are Aframomum melegueta and Spondis mombin (Linn). Both contains arrays of natural product that may be used for drug formulation to combat SARS-CoV-2, Aframomum melegueta medicinal plant belong to the family Zingiberaceae which can be used to detoxify liver and bronchitis during lungs infection. Aframomum melegueta contains 6-Gingerol, 8-Gingerol, Methyl-6-Gingerol, 6-Shogaol, 6-Rac-6-Dihydro paradol,6-Gingeredione, 2-(5 butylfuran-2-yl) ethyl}-2-methoxyphenol and 6-Paradol. Secondary metabolite(Phytochemical)investigations of Aframomum melegueta extracts revealed the presence of (-)-buplerol, (-)-arctigenin, (E)- 14-hydroxy-15-norlabda-8(17), 12-dien- 16-al, labda-8(17), 12-dien-15, 16- dial, 16-oxo-8(17), 12(E)-labdadien-15-oic acid, 5-hydroxy-7-methoxy flavone and apigenin, The combination of all this novel compound can be used for the treatment of SARS-CoV-2. Spondias mombin belongs to the family of Anacardiaceae medicinal plants and contains Catechin and Epigalocatechin, Epicatechin, Stigmasterol and Phytosterol, a very important flavonoid that can be used in drug formulation because of its extensive therapeutic properties which may inhibit specific enzymes, blocking the angiotensin-converting enzyme (ACE) that raises blood pressure of infected patient during elevated fever clinical symptoms of SARS-CoV-2 (COVID-19). Spondias monbin extract may act by blocking the “suicide” enzyme cyclooxygenase that breaks down prostaglandins, they also prevent platelet aggregation. Cancer-battling antioxidants, flavonoids, have been found in relative abundance in Aframomum melegueta and Spondias mombin. Epicatechin have been proven to have diverse benefits to human health. It reduces the risks of diabetes mellitus and cardiovascular diseases, EGC acts as a strong inhibitor of HIV replication in cultured peripheral blood cells and inhibition of HIV-1 reverse transcriptase in vitro. EGC binds directly to CD4 molecules with consequent inhibition of Gp 120 binding and inactivate viruses in vitro by deformation of phospholipids, Epicatechin and other polyphenols decreases the susceptibility of low density lipoprotein to oxidation which prevents the initiation of artherosclerosis, HIV protein (Tat) and gp120.In conclusion. SARS-CoV-2(COVID-19) pandemic infection should not be a death sentence, it should be an advancement into the scientific world especially the naturally occurring product that can be used in the formulation of new antimicrobial agents.

Elevated blood glucose levels, insulin resistance (IR), hyperinsulinemia and dyslipidemia the key aspects of type 2 diabetes mellitus (T2DM), contribute to the development of a certain form of cardiomyopathy. This cardiomyopathy, also known as diabetic cardiomyopathy (DMCM), typically occurs in the absence of overt coronary artery disease (CAD), hypertension or valvular disease. DMCM encompasses a variety of pathophysiological processes impacting the myocardium, hence increasing the risk for heart failure (HF) and significantly worsening outcomes in this population. Low fat (LF), calorie-restricted diets have been suggested as the preferred eating pattern for patients with HF. However, LF diets are naturally higher in carbohydrates (CHO). We argue that in an insulin resistant state, such as in DMCM, LF diets may worsen glycaemic control and promote further insulin resistance (IR), contributing to a physiological and functional decline in DMCM. We postulate that CHO restriction targeting hyperinsulinemia may be able to improve tissue and systemic IR. In recent years low carbohydrate diets (LC) including ketogenic diets (KD), have emerged as a safe and effective tool for the management of various clinical conditions such as T2DM and other metabolic disorders. CHO restriction achieves sustained glycaemic control, lower insulin levels and successfully reverses IR. In addition to this, its pleiotropic effects may present a metabolic stress defense and facilitate improvement to cardiac function in patients with HF. We therefore hypothesize that patients who adopt a LC diet may require less medications and experience improvements in HF-related symptom burden.

Encephalomyocarditis virus (EMCV) infects a wide range of hosts and can cause encephalitis, myocarditis, reproductive disorders and diabetes mellitus in selected mammalian species. As for humans, EMCV infection seems to occur by the contact with animals and can cause febrile illnesses in some infected patients. Here we isolated EMCV strain ZM12/14 from a natal multimammate mouse (Mastomys natalensis: M. natalensis) in Zambia. Pairwise sequence similarity of the ZM12/14 P1 region consisting of antigenic capsid proteins showed the highest similarity of nucleotide (80.7 %) and amino acid (96.2%) sequence with EMCV serotype 1 (EMCV-1). Phylogenetic analysis revealed that ZM12/14 clustered into EMCV-1 at the P1 and P3 regions but segregated from known EMCV strains at the P2 region, suggesting a unique evolutionary history. Reverse transcription PCR (RT-PCR) screening and neutralizing antibody assays for EMCV were performed using collected tissues and serum from various rodents (n=179) captured in different areas in Zambia. We detected the EMCV genome in 19 M. natalensis (19/179=10.6 %) and neutralizing antibody for EMCV in 33 M. natalensis (33/179=18.4 %). However, we did not detect either the genome or neutralizing antibody in other rodent species. High neutralizing antibody litres (≧320) were observed in both RT-PCR-negative and -positive animals. Inoculation of ZM12/14 caused asymptomatic persistent infection in BALB/c mice with high antibody titres and high viral loads in some organs, consistent with the above epidemiological results. This study is the first report of the isolation of EMCV in Zambia, suggesting that M. natalensis may play a role as a natural reservoir of infection.