Academic literature on the topic 'Prednisone – Physiological effect'

Background:Cenerimod is a potent, selective, and orally active sphingosine 1-phosphate receptor 1 (S1P1) modulator that is currently being evaluated in a Phase 2b study in patients with systemic lupus erythematosus (SLE) (NCT03742037). S1P1 receptor modulators sequester circulating lymphocytes within lymph nodes, thereby reducing pathogenic autoimmune cells (including B lymphocytes) in the blood stream and in inflamed tissues. Extensive clinical experience has become available for the nonselective S1P receptor modulator fingolimod in relapsing forms of multiple sclerosis, supporting this therapeutic concept for the treatment of autoimmune disorders.Objectives:Although the effect of S1P-receptor modulators in reducing peripheral B cells is well documented1,2, the role of the S1P1 receptor on this cell type is only incompletely understood. In this study, the mode of action of cenerimod on primary human B cells was investigated in a series of in vitro experiments, including S1P1 receptor cell surface expression and chemotaxis towards S1P. Moreover, S1P1 expression following B cell activation in vitro was studied. As glucocorticoids (GC) are frequently used in the treatment of patients with autoimmune disorders including SLE, the potential influence of GC on the mode of action of cenerimod was evaluated.Methods:Primary human B lymphocytes from healthy donors were isolated from whole blood. In one set of experiments, cells were treated with different concentrations of cenerimod to measure S1P1 receptor internalization by flow cytometry. In a second set of experiments, isolated B cells were activated using different stimuli or left untreated. Cells were then analysed for S1P1 and CD69 cell surface expression and tested in a novel real-time S1P-mediated migration assay. In addition, the effect of physiological concentrations of GCs (prednisolone and prednisone) on cenerimod activity in preventing S1P mediated migration was tested.Results:In vitro, cenerimod led to a dose-dependent internalization of the S1P1 receptor on primary human B lymphocytes. Cenerimod also blocked migration of nonactivated and activated B lymphocytes towards S1P in a concentration-dependent manner, which is in line with the retention of lymphocytes in the lymph node and the reduction of circulating lymphocytes observed in the clinical setting. Upon B cell activation, which was monitored by CD69 upregulation, a simultaneous downregulation of S1P1 expression was detected, leading to less efficient S1P-directed cell migration. Importantly, physiological concentrations of GC did not affect the inhibitory activity of cenerimod on B cell migration.Conclusion:These results show that cenerimod, by modulating S1P1, blocks B lymphocyte migration towards its natural chemoattractant S1P and demonstrate compatibility of cenerimod with GC. These results are consistent with results of comparable experiments done previously using primary human T lymphocytes.References:[1]Nakamura M et al., Mult Scler. 2014 Sep; 20(10):1371-80.[2]Strasser DS et al., RMD Open 2020;6:e001261.Disclosure of Interests:None declared

Abstract Abstract 814 The goal of this study was to find small molecules that stimulate erythropoiesis at an earlier stage than erythropoietin (Epo). We therefore studied the mechanisms by which glucocorticoids (GCs) promote erythroblast formation during stress erythropoiesis (SE). Since the target cell of GCs in SE was not known we first established a FACS-based method to purify burst-forming unit erythroid (BFU-E) and colony-forming unit of erythroid lineage (CFU-E) cells from mouse fetal liver. BFU-E and CFU-E cells were resolved by differences in CD71 or CD24a expression (BFU-E = CD71/CD24a10% low; CFU-E = CD71/CD24a20% high) from a population of cells positive for Kit, and negative for the cell surface markers Ter119, B220, Mac-1, CD3, Gr-1, Sca-1, FcGR, CD41 and CD34. Purified “BFU-E” cells formed 94% BFU-E colonies and “CFU-E” cells formed 95% CFU-E colonies at cloning efficiencies of 55–70%. Using pure CFU-E and BFU-E progenitors we demonstrated that while 100nM Dexamethasone (Dex) does not increase proliferation or self-renewal of CFU-E cells, Dex stimulates the earlier BFU-E progenitors to undergo limited self-renewal, which increases formation of CFU-E cells and erythroblasts >20-fold. After identifying BFU-E progenitors as the target cells of GCs during SE, we next determined how DEX changes miRNA and mRNA expression in BFU-Es by next generation sequencing. No miRNAs changed the level of expression more than 50%. Of the 10,000 most expressed mRNAs 83 were up-regulated and 112 mRNAs down-regulated more than 2-fold in response to Dex. Since previous studies show that dimerization (trans activation) of the GC receptor is necessary for GCs to induce erythroblast production, the most important GC target genes are likely up- rather than down-regulated. We hypothesized that other molecules that are able to enhance the expression of the 83 up-regulated genes could enhance or replace the stimulatory effect of Dex. We therefore computationally analyzed the promoter regions of the up-regulated genes using motif enrichment analysis. We found that Dex induces expression of genes in BFU-E cells that contain promoter regions highly enriched for hypoxia-induced factor 1 alpha (HIF1a) binding sites (p-value = 1e–27). Analysis of six published gene expression datasets, where the effect of GCs on gene expression had been determined in cell types other than BFU-E cells, showed very low or no enrichment of HIF1a targets among genes up-regulated by Dex. We confirmed the suggested overlapping effects of HIF1a and GCs on gene expression in BFU-E cells by comparing the effect of Dex with that of pharmacological HIF1a activation by the prolyl hydroxylase inhibitor (PHI) Dimethyloxalylglycine (DMOG). As determined by next generation mRNA sequencing, DMOG increased expression of 98 genes more than 50%, of which 28 were among 109 genes up-regulated >50% by Dex (p-value for overlap = 1e–26). Importantly the overlap in effects on gene expression also resulted in overlapping biological effects. Similar to Dex, DMOG had little effect on CFU-E cells (Figure A). In contrast DMOG synergized with Dexamethasone to promote BFU-E self-renewal and prevent BFU-E cell exhaustion, enhancing the production of CFU-E cells 170-fold and maximum erythroblast production 300-fold (Figure B). DMOG thus enhanced the stimulatory effect of 100nM Dex on erythroblast production 7-fold. In similar experiments where BFU-E cells were cultured in GCs levels corresponding to physiological cortisol levels (1 nM Dex), DMOG enhanced erythroblast production 10-fold. We further showed that DMOG and Dex also synergistically enhance proliferation of adult mouse and human erythroid progenitors. Our results support a physiological model of SE where increased systemic levels of free cortisol, in combination with local anoxia, induce BFU-E self-renewal and increase erythroblast production. This suggests that the therapeutic potential for PHIs in treatment for anemia goes beyond replacing recombinant Epo. Here we show that in addition to enhancing Epo production from the kidneys, PHIs have an intrinsic stimulatory effect on BFU-E progenitors, leading to increased production of Epo-responsive CFU-E cells. Thus PHIs provide a new window for treating Epo-resistant anemia. The synergistic effect of GCs and PHIs further suggests that PHIs may enhance or replace the effect of Prednisone in the treatment of Diamond-Blackfan Anemia and other bone marrow failure syndromes. Disclosures: No relevant conflicts of interest to declare.

The review considers the data on the physiological and pharmacological effects of glucocorticoids on the gastric mucosa and focuses on the gastroprotective role of stress-produced glucocorticoids as well as on the transformation of physiological gastroprotective effects of glucocorticoids to pathological proulcerogenic consequences. The results of experimental studies on the re-evaluation of the traditional notion that stress-produced glucocorticoids are ulcerogenic led us to the opposite conclusion suggested that these hormones play an important role in the maintenance of the gastric mucosal integrity. Exogenous glucocorticoids may exert both gastroprotective and proulcerogenic effects. Initially, gastroprotective effect of dexamethasone but not corticosterone, cortisol or prednisolone can be transformed into proulcerogenic one. The most significant factor for the transformation is the prolongation of its action rather the dose. Gastrointestinal injury can be accompanied by changes in somatic pain sensitivity and glucocorticoids contribute to these changes playing a physiological and pathological role.

Abstract. Previously, we reported elevated plasma immunoreactive ANP (irANP) levels from the 2nd to the 9th day of administering either prednisone, 50 mg/day, or 9α-fludrocortisone acetate (9αF), 0.6 mg/day, to normal humans. To investigate the course of plasma irANP levels during the first 48 h of corticosteroid adminstration, 9 healthy men (mean age ± sem, 24 ± 1 years) received in randomised sequence A) a 4-h iv infusion of prednisolone sodium tetrahydrophthalate followed by oral administration of prednisone for 2 days; or B) a 4-h infusion of aldosterone followed by oral administration of 9αF for 2 days. Basal supine plasma irANP levels averaged 32 ± 5 ng/l in study A and 30 ± 6 ng/l in study B; they were unchanged or even deceased up to 24 h of glucocorticoid or mineralocorticoid administration, but rose (P < 0.01) to 56 ± 9 and 62 ± 12 ng/l at 48 h, respectively, of the two interventions. During glucocorticoid treatment, blood pressure (BP) and indices of the sodium-fluid volume state were unchanged after 48 h. During 9αF administration, body weight increased (1.1 ± 0.3%, P < 0.001), whereas urinary sodium excretion (63 ±7%, P < 0.001), hematocrit (4.1 ± 1.1%, P < 0.001), and plasma renin activity (38 ± 4%, P < 0.001) decreased. Conclusions: The increase in circulating irANP at 48 h of administration of either a glucocorticoid or a mineralocorticoid demonstrates a distinct but slow response of the ANP system to these corticosteroids in normal humans. ANP may play a potential role in mediating and/or modulating physiological and pathophysiological effects of corticosteroids.

Abstract Abstract 3175 Introduction: Patients with multiple myeloma (MM) have an increasing risk of developing venous thromboembolism (VTE). The use of thalidomide or lenalidomide, two antimyeloma agents has been associated with an increased risk of VTE especially when associated with dexamethasone or melphalan-prednisone. This increased risk in less pronounced with the proteasome inhibitor bortezomib. The pharmacological effects of thalidomide, lenalidomide and bortezomib have never been studied on platelet aggregation or coagulation. These preliminary data are necessary to understand the differential effects of these drugs on thrombotic events. Aims: The aim of our study is to investigate the pharmacological effects of these drugs on primary hemostasis by light transmission agregometry (LTA) and on secondary hemostasis using thrombin generation test (TGT). Methods: LTA was performed with a Chrono-Log aggregometer (Kordia). Platelet-rich plasma (PRP) of healthy blood donors (n=3 to 10) was adjusted to 300,000 platelets/μl. Platelet-poor plasma (PPP) and PRP were used respectively to adjust the photometric measurement to the minimum and maximum optical density. The platelet reactivity of the healthy donors was previously checked by LTA. Thalidomide (racemic, enantiomer (+) and enantiomer (-)), lenalidomide and bortezomib were spiked at final concentration of 200 μM in PRP except for studying the influence of thalidomide on ADP-induced platelet aggregation where the maximal concentration usable was 100 μM. LTA was performed without (spontaneous aggregation) and with addition of 5μM ADP, 190μg/ml collagen, 600μM arachidonic acid (AA) and 10 μM PAR1-AP (final concentrations). Negative controls (physiological saline and DMSO at concentrations used to dissolve the drugs) were also included. TGT was performed both on PPP (from normal pool plasma (NPP)) and on PRP. We first validated the method on NPP and PRP with two anticoagulants: a thrombin direct inhibitor (i.e. argatroban) and a FXa direct inhibitor (i.e. ZK-807834). Thalidomide ((+/−), (+) and (-)), lenalidomide and bortezomid were tested at the final concentrations of 5, 10, 50, 100 and 200 μM. For the experiments on NPP, PPP reagent (5 pM TF + 4 μM PL in the final assays), PPP reagent low (1 pM TF + 4 μM PL in the final assays) and MP reagent (4 μM PL in the final assays) were used whereas for the experiments on PRP, PRP reagent (1 pM TF in the final assays) was used. Results: LTA Both three drugs did not induce spontaneous aggregation until 200 μM. Lenalidomide and bortezomib showed no effect on induced platelet aggregation until 200 μM, whatever the agonist used. On the contrary, for racemic thalidomide, platelet aggregation was reduced at 50 and 100 μM with 5 μM ADP and at 150 and 200 μM with 600 μM AA. These effects were more pronounced with thalidomide (+) than with thalidomide (-). So, the half maximal inhibitory concentrations (IC50) for platelet aggregation induced by 600 μM AA were 127, 143 and 221 μM for racemic, enantiomer (+) and enantiomer (-), respectively. When 190μg/ml collagen or 10 μM PAR1-AP were used as agonists, no effect was observed on platelet aggregation until 200 μM thalidomide. TGT. With argatroban and ZK-807834, we observed a concentration-dependent decrease and delay of the thrombin activity profiles in PRP and NPP, whatever the inducer used. No significant effect on thrombin activity in NPP or PRP has been observed for antimyeloma drugs at all concentrations tested, whatever the inducer used. Conclusions: Lenalidomide, thalidomide and bortezomid do not induce spontaneous platelet aggregation and do not affect platelet aggregation induced by collagen or PAR1-AP. Conversely to lenalidomide and bortezomib, thalidomide, and especially its enantiomer (+), moderately inhibits platelet aggregation induced by ADP and AA. Moreover, these antimyeloma agents have no effect on thrombin generation. The increased risk of VTE by thalidomide or lenalidomide in patients with multiple myeloma is thus not mediated by a direct impact on primary or secondary hemostasis at therapeutic concentrations. Disclosures: No relevant conflicts of interest to declare.

The aim of this study was to investigate the effect of different doses of prednisolone in puppies experimentally induced with meconium aspiration syndrome (MAS). Meconium was collected from human babies in the first day of life and was released into the trachea of 11 newborn puppies to induce MAS. Puppies were treated with 2 mg/kg prednisolone (standard dose), 30 mg/kg prednisolone (megadose) or 0.9% saline, all administered intravenously. The study ended 20 h after meconium aspiration and the lungs were then scored for histopathology. Animals not treated with prednisolone deteriorated after 8 h while respiration rate, oxygenation, pH and partial pressure of carbon dioxide values were better in the prednisolone-treated groups. Histopathology scores were better in the treatment groups compared with the control group, with megadose giving the best result. At the end of the study, serum malondialdehyde levels were significantly higher in the megadose prednisolone group compared with the other two groups. In conclusion, we determined that prednisolone reduced physiological and histological changes in puppies with MAS and that a 30 mg/kg dose was more effective than 2 mg/kg.

e14587 Background: Immune checkpoint inhibitor (ICI) therapy has improved survival of patients with melanoma and other types of cancers. The effect of immunosuppresive corticosteroids on ICI efficacy is unknown, however treatment of immune-related adverse events with high-dose steroid therapy impairs neither efficacy nor time to failure of ICI. In certain clinical circumstances (for instance in the treatment of patients with symptomatic brain metastases) it may be advantageous to begin ICI therapy despite a requirement for steroid therapy. This study examined the effect of high-dose steroid therapy on lymphocyte proliferation/functionality after stimulation with anti-CD3 in the presence of pembrolizumab (PD-1 inhibitor) ex vivo. Methods: Peripheral blood mononuclear cells (PBMCs) were collected from patients with either chronic hepatitis C infection or active malignant melanoma. CD4+ and CD8+ T cells were isolated and subjected to flow cytometry stating for the expression of PD-1. Isolated PBMCs were then pre-treated with prednisone (1 nM - 1 mM) before anti-CD3 stimulation. Anti-CD3-stimulated cells were then incubated with pembrolizumab (5 µg/mL) and their proliferative capacity and IL-2 secretion ability were measured by carboxyfluorescein succinimidyl ester (CFSE) staining and ELISA, respectively. Results: A dose-dependent inhibition of both lymphocyte proliferation and IL-2 production was observed, but at physiologically relevant nanomolar prednisone concentration the steroid effect was negligible. Millimolar prednisone concentrations resulted in > 50% relative reduction in lymphocyte proliferation, however even at this steroid concentration treatment with pembrolizumab was able to further stimulate proliferation and IL-2 secretion versus anti-CD3stimulation alone. Conclusions: Despite heavily immunosuppressive treatment, CD4+ and CD8+ lymphocytes demonstrate proliferative capacity and immunological activity following treatment with pembrolizumab. This suggests that treatment with pembrolizumab may be efficacious despite a requirement for steroid therapy, a scenario often encountered in patients with brain metastases.

Context Patients with primary adrenal insufficiency (PAI) or congenital adrenal hyperplasia (CAH) receive life-long glucocorticoid (GC) therapy. Daily GC doses are often above the physiological cortisol production rate and can cause long-term morbidities such as osteoporosis. No prospective trial has investigated the long-term effect of different GC therapies on bone mineral density (BMD) in those patients. Objectives To determine if patients on hydrocortisone (HC) or prednisolone show changes in BMD after follow-up of 5.5 years. To investigate if BMD is altered after switching from immediate- to modified-release HC. Design and patients Prospective, observational, longitudinal study with evaluation of BMD by DXA at visit1, after 2.2 ± 0.4 (visit2) and after 5.5 ± 0.8 years (visit3) included 36 PAI and 8 CAH patients. Thirteen patients received prednisolone (age 52.5 ± 14.8 years; 8 women) and 31 patients received immediate-release HC (age 48.9 ± 15.8 years; 22 women). Twelve patients on immediate-release switched to modified-release HC at visit2. Results Prednisolone showed significantly lower Z-scores compared to HC at femoral neck (−0.85 ± 0.80 vs −0.25 ± 1.16, P < 0.05), trochanter (−0.96 ± 0.62 vs 0.51 ± 1.07, P < 0.05) and total hip (−0.78 ± 0.55 vs 0.36 ± 1.04, P < 0.05), but not at lumbar spine, throughout the study. Prednisolone dose decreased by 8% over study time, but no significant effect was seen on BMD. BMD did not change significantly after switching from immediate- to modified-release HC. Conclusions The use of prednisolone as hormone replacement therapy results in significantly lower BMD compared to HC. Patients on low-dose HC replacement therapy showed unchanged Z-scores within the normal reference range during the study period.

This study was performed to assess the clincotherapeutic effect of whole venom of honeybee (Apis mellifera) in adjuvant-induced arthritic rat. Ninety Sprague-Dawley male rats were injected with complete Freund's adjuvant (CFA). Adjuvant arthritis was produced by a single subcutaneous injection of 1 mg Mycobacterium butyricum suspended in 0.1 ml paraffin oil into the right hind paw. Righting reflex was uniformly lost and considered to be the point of arthritis development on day 14 after CFA injection. The experiments were divided into three groups. When arthritis was developed in the rat, tested groups were administered with prednisolone (10 mg/kg, p.o.) or honeybee venom (one bee, s.c.) every other day for another 14 days. Control group was injected with 0.1 ml of physiological saline solution subcutaneously. Clinical and hematological values with histopathological findings were observed during the drug administration. In treatment groups, the development of inflammatory edema and polyarthritis was suppressed. No significant differences of hind paw edema volume and lameness score between prednisolone and honeybee venom groups were observed during treatment. White blood cell counts of control group showed leucocytosis that was significantly different from the two treatment groups (p < 0.01). Erosions of articular cartilage and inflammatory cell infiltrations into interphalangeal joint were effectively suppressed in treated groups. In conclusion, whole honeybee venom was found to suppress arthritic inflammation in the rat. This may be an alternative treatment of arthritic agony in humans.