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1
Sunaryo, Sagara Mahardika, Lukas Chrisantyo, and Yuan Lukito. "ANALISIS ALGORITMA MTF, MTF-1 DAN MTF-2 PADA BURROWS WHEELER COMPRESSION ALGORITHM." Jurnal Terapan Teknologi Informasi 3, no. 1 (July 1, 2019): 21–30. http://dx.doi.org/10.21460/jutei.2019.31.148.
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Kebutuhan kompresi data teks di era komputasi awan saat ini masih cukup tinggi. Data teks perlu dikompresi sekecil mungkin agar mudah dikirimkan. Burrows Wheeler Compression Algorithm (BWCA) adalah salah satu algoritma kompresi teks jenis block sorting yang bersifat non-proprietary dan cukup populer digunakan. Dalam prosesnya, BWCA menggunakan metode pemrosesan awal yang disebut Global Structure Transformation (GST) untuk menyusun karakter agar lebih baik hasil kompresinya. Penelitian ini membandingkan tiga metode pemrosesan awal Move-to-Front, yaitu MTF, MTF-1 dan MTF-2. Bahan uji kompresi berupa data Alkitab Bahasa Inggris, Indonesia dan Jawa, dan beberapa data yang berasal dari Calgary Corpus. Oleh karena kompresi teks adalah kompresi yang bersifat lossless dan reversibel, maka selain melakukan pengujian untuk pengompresian data, juga dilakukan pengujian untuk pendekompresian data dengan Inverse Burrows Wheeler Transform. Pengujian kompresi dan dekompresi pada data Alkitab maupun Calgary Corpus berhasil dilakukan dan menunjukkan MTF-1 mampu memberikan rasio kompresi yang lebih baik dikarenakan jumlah total tiap bit pada proses Huffman lebih sedikit dibandingkan dua metode lainnya.
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Sekyere, Eric O., Louise L. Dunn, Yohan Suryo Rahmanto, and Des R. Richardson. "Role of melanotransferrin in iron metabolism: studies using targeted gene disruption in vivo." Blood 107, no. 7 (April 1, 2006): 2599–601. http://dx.doi.org/10.1182/blood-2005-10-4174.
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AbstractMelanotransferrin (MTf) or tumor antigen p97 is a transferrin homolog that binds one iron (Fe) atom and has been suggested to play roles in a variety of processes, including Fe metabolism, eosinophil differentiation, and plasminogen activation. Considering the vital role of Fe in many metabolic pathways, such as DNA and heme synthesis, it is important to understand the function of MTf. To define this, a MTf knockout (MTf–/–) mouse was generated through targeted disruption of the MTf gene. The MTf–/– mice were viable and fertile and developed normally, with no morphologic or histologic abnormalities. Assessment of Fe indices, tissue Fe levels, hematology, and serum chemistry parameters demonstrated no differences between MTf–/– and wild-type (MTf+/+) mice, suggesting MTf was not essential for Fe metabolism.
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Meligi, Noha M., Amro K. F. Dyab, and Vesselin N. Paunov. "Sustained In Vitro and In Vivo Delivery of Metformin from Plant Pollen-Derived Composite Microcapsules." Pharmaceutics 13, no. 7 (July 9, 2021): 1048. http://dx.doi.org/10.3390/pharmaceutics13071048.
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We developed a dual microencapsulation platform for the type 2 diabetes drug metformin (MTF), which is aimed to increase its bioavailability. We report the use of Lycopodium clavatum sporopollenin (LCS), derived from their natural spores, and raw Phoenix dactylifera L. (date palm) pollens (DPP) for MTF microencapsulation. MTF was loaded into LCS and DPP via a vacuum and a novel method of hydration-induced swelling. The loading capacity (LC) and encapsulation efficiency (EE) percentages for MTF-loaded LCS and MTF-loaded DPP microcapsules were 14.9% ± 0.7, 29.8 ± 0.8, and 15.2% ± 0.7, 30.3 ± 1.0, respectively. The release of MTF from MTF-loaded LCS microcapsules was additionally controlled by re-encapsulating the loaded microcapsules into calcium alginate (ALG) microbeads via ionotropic gelation, where the release of MTF was found to be significantly slower and pH-dependent. The pharmacokinetic parameters, obtained from the in vivo study, revealed that the relative bioavailability of the MTF-loaded LCS-ALG beads was 1.215 times higher compared to pure MTF, following oral administration of a single dose equivalent to 25 mg/kg body weight MTF to streptozotocin (STZ)-induced diabetic male Sprague-Dawley rats. Significant hypoglycemic effect was obtained for STZ-induced diabetic rats orally treated with MTF-loaded LCS-ALG beads compared to control diabetic rats. Over a period of 29 days, the STZ-induced diabetic rats treated with MTF-loaded LCS-ALG beads showed a decrease in the aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglycerides, cholesterol, and low-density lipoprotein-cholesterol (LDL-C) levels, as well as an increase in glutathione peroxidase (GPx) and a recovery in the oxidative stress biomarker, lipid peroxidation (LPx). In addition, histopathological studies of liver, pancreas, kidney, and testes suggested that MTF-loaded LCS-ALG beads improved the degenerative changes in organs of diabetic rats. The LCS-ALG platform for dual encapsulation of MTF achieved sustained MTF delivery and enhancement of bioavailability, as well as the improved biochemical and histopathological characteristics in in vivo studies, opening many other intriguing applications in sustained drug delivery.
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LAROCHELLE, Olivier, Gale STEWART, Pierre MOFFATT, Véronique TREMBLAY, and Carl SÉGUIN. "Characterization of the mouse metal-regulatory-element-binding proteins, metal element protein-1 and metal regulatory transcription factor-1." Biochemical Journal 353, no. 3 (January 25, 2001): 591–601. http://dx.doi.org/10.1042/bj3530591.
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Metal activation of metallothionein gene transcription depends mainly on the presence of regulatory DNA sequences termed metal-regulatory elements (MREs) and involves MRE-binding transcription factor-1 (MTF-1) interacting with the MREs in a Zn2+-dependent manner. We previously identified and characterized a nuclear protein, termed metal element protein-1 (MEP-1), specifically binding with high affinity to MRE elements. The precise relationship between MTF-1 and MEP-1 was unclear, and to determine whether MEP-1 and MTF-1 were distinct protein species, we performed DNA binding analyses to characterize the binding properties of both proteins. Electrophoretic mobility-shift assays showed that MTF-1, produced in COS cells, produces a slower-migrating band compared with that obtained with purified MEP-1. Using an anti-MTF-1 antibody, we showed that both the MTF-1–MRE and the MEP-1–MRE complexes are supershifted by an anti-MTF-1 antibody, thus demonstrating that MEP-1 is antigenically related to MTF-1. RNase protection analyses carried out with RNA prepared from different tissues and cell lines failed to reveal the presence of MTF-1 splicing variants. This indicates that MEP-1 may be a proteolytic fragment of MTF-1. MTF-1 DNA-binding activity was rapidly activated in vivo by Zn2+ ions but not by Cd2+, UV irradiation or PMA, and occurred on ice as well as at 21°C. In control and Zn2+-treated cell extracts, DNA-binding activity was not enhanced in vitro following the addition of exogenous Zn2+ or a preincubation at 37°C. However, recombinant MTF-1 produced in vitro required Zn2+ activation for DNA binding. Interestingly, treatment of nuclear extracts with calf intestine phosphatase completely abrogated MTF-1 DNA-binding activity, thus suggesting that phosphorylation is involved in the regulation of MTF-1 activity.
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Anam, Choirul, Ariij Naufal, Heri Sutanto, and Geoff Dougherty. "Computational phantoms for investigating impact of noise magnitude on modulation transfer function." Indonesian Journal of Electrical Engineering and Computer Science 27, no. 3 (September 1, 2022): 1428. http://dx.doi.org/10.11591/ijeecs.v27.i3.pp1428-1437.
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Accurate measurement of spatial resolution in terms of modulation transfer function (MTF) is essential in computed tomography (CT) images. The purpose of this study was to developed a computational phantom that can be used to evaluate the effect of noise on the MTF in CT images. Our computational phantoms for measuring MTF in CT were developed with MATLAB software. The phantom image was blurred by a point spread function of a certain standard deviation. Subsequently, different noise levels were added to the phantoms. Next, an automatic MTF calculation was implemented. The first step of the MTF calculation was to determine the region of interest (ROI). Profile was generated from the ROI, and a line spread function (LSF) curve was formed. The LSF curve was Fourier transformed to produce a MTF curve. Greater noise added to phantom image, it yields greater effect of standard deviation on the measured MTF. The greater noise makes the MTF curve increases differently than MTF with 0 HU noise. The 10% MTF values at the 25% noise reach more than 2.0 cycle/mm. By the developed computational phantoms, the spatial resolution and the amount of noise can be determined independently.
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Jiang, Jehn-Ruey, and Cheng-Tai Yen. "Product Quality Prediction for Wire Electrical Discharge Machining with Markov Transition Fields and Convolutional Long Short-Term Memory Neural Networks." Applied Sciences 11, no. 13 (June 25, 2021): 5922. http://dx.doi.org/10.3390/app11135922.
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This paper proposes a wire electrical discharge machining (WEDM) product quality prediction method, called MTF-CLSTM, to integrate the Markov transition field (MTF) and the convolutional long short-term memory (CLSTM) neural network. The proposed MTF-CLSTM method can accurately predict WEDM workpiece surface roughness right after manufacturing by collecting and analyzing static machining parameters and dynamic manufacturing conditions. The highly accurate prediction is due to the following two reasons. First, MTF can transform data into images to extract data temporal information and state transition probability information. Second, the CLSTM neural network can extract image spacial features and temporal relationship of data that are separated far apart. In short, MTF-CLSTM predicts WEDM workpiece surface roughness with the MTF model and the CLSTM neural network using static machining parameters and dynamic manufacturing conditions. MTF-CLSTM is compared with 10 related research studies in many aspects. There is only one existing method that is like MTF-CLSTM to predict WEDM workpiece surface roughness by using static machining parameters and dynamic manufacturing conditions. Experiments are conducted to evaluate MTF-CLSTM performance to show that MTF-CLSTM significantly outperforms the existing method in terms of the prediction mean absolute percentage error.
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Yang, G., F. D. Coffman, and E. F. Wheelock. "Characterization and purification of a macrophage-triggering factor produced in Mycoplasma arginini-infected L5178Y cell cultures." Journal of Immunology 153, no. 6 (September 15, 1994): 2579–91. http://dx.doi.org/10.4049/jimmunol.153.6.2579.
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Abstract The supernatant of Mycoplasma arginini-infected murine L5178Y T lymphoma cell cultures (SN-L51) synergizes with small concentrations of IFN-gamma to activate murine peritoneal, thioglycollate-elicited macrophages (M phi) to exhibit cytostatic activity against tumor cells. Treatment of M phi with IFN-gamma and SN-L51 sequentially, but not in the reverse order, activates M phi, which indicates that SN-L51 contains a M phi-triggering factor (MTF). MTF activity could be inhibited by small concentrations of prostaglandin E2, but not by polymyxin B. M phi activated by IFN-gamma plus MTF produce cytostatic effects on tumor cells through a nitric oxide-dependent pathway. MTF activity in SN-L51 is associated with infection of L5178Y cells by M. arginini. Mycoplasma-free L5178Y cells do not produce MTF activity, infection of these L5178Y cells with M. arginini generates the activity, and supernatants of pure M. arginini cultures contain MTF activity. MTF activity is thermostable and resistant to acid, dilute alkali, proteases, and nucleases. MTF was partially purified by ammonium sulfate precipitation, chromatography, electrophoresis, and electroelution. On 12.5% SDS-urea gels, MTF activity migrated with a molecular mass of 2.5 to 4 kDa. MTF activity and the silver staining of this band was resistant to proteinase K; however, Coomassie staining of this band was abolished by proteinase K. The combined data suggest that MTF is either a stable peptide or a peptide linked to lipid or carbohydrate.
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Keum, Woong-Jin, Moo-geon Kim, Ju-Wan Hong, and Yung-Kyoon Kim. "A Study on Spatial Resolution according to Composition Material of ACR phantom in MDCT." Korean Society of Computed Tomographic Technology 24, no. 2 (September 30, 2022): 35–42. http://dx.doi.org/10.31320/jksct.2022.24.2.35.
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The modulation transfer function (MTF) is well known as a crucial parameter in quality assurance of computed tomography (CT) scanners that provides detailed information of both contrast and resolution of CT images. In this study, modulation transfer function (MTF) of multi-detector computed tomography (MDCT) was evaluated by changing the substance of phantom and the measurement parameters. The analysis of MTF gives following results: 1) Bone (the highest contrast material) and air (the lowest contrast material) exhibited variance by 0.030 lp/cm at MTF(50%). 2) In addition, slice thickness of 1.25-mm and 10.0-mm exhibited 0.110 lp/cm and 0.065 lp/cm at MTF(50%), respectively. 3) MTF (50%) showed 50.31% difference depending on the image reconstruction algorithm. Especially, bone algorithm showed higher MTF (50%) than standard algorithm by 26.69%. 4) In addition, the Full (360°) mode linear interpolation showed higher MTF (50%) than the Plus (540°) mode by 10.71%. For a accurate measurement of MTF while performing CT quality control, a phantom module which consists of diverse substance is required. Also, the optimal image which reflecting the size and shape of lesion can be obtained with a suitable scanning factor for diagnosis.
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Porta, Matteo G. Della, Vittorio Rosti, Anna Gallì, Erica Travaglino, Paolo Santambrogio, Carmela Marseglia, Valentina Matti, et al. "The Effects of Mitochondrial Ferritin Expression in Normal and Sideroblastic Erythropoiesis." Blood 114, no. 22 (November 20, 2009): 736. http://dx.doi.org/10.1182/blood.v114.22.736.736.
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Abstract Abstract 736 In erythroid cells from patients with refractory anemia with ringed sideroblasts (RARS), the expression of mitochondrial ferritin (MtF) - encoded by the nuclear FTMT gene located on chromosome 5q21.3 - occurs at a very early stage of differentiation and is closely related to the sideroblastic phenotype [Blood. 2003 Mar 1;101(5):1996-2000]. On the other hand, in extra-hematopoietic tissues MtF expression is associated with high cellular metabolic activity and oxygen consumption, suggesting a possible role of this protein in protecting mitochondria from iron-dependent oxidative damage. It is known that reactive oxygen species (ROS) act as second messengers in the JAK/STAT pathway, which is involved in the regulation of erythropoiesis, and that ROS scavengers inhibit STAT5 phosphorylation. It was the aim of this study to investigate the influence of experimentally induced MtF over-expression on erythroid differentiation in normal hematopoietic progenitors, and in addition to define the relationship between MtF expression and erythroid maturation, apoptosis, and JAK-STAT pathway activation in RARS. A liquid culture model was adopted to expand erythroid progenitors from CD34+ cells in the presence of IL-3, IL-6, stem cell factor and Epo [Blood. 2005 Jul 1;106(1):247-53]. To study the effect of MtF induction in normal hematopoiesis, CD34+ cells from 5 healthy donors were transduced using lentivirus carrying cDNA of FTMT downstream to the ubiquitous PGK promoter (transduction efficiency equal to 30-40%), and then cultured for 21 days. To assess the effect of MtF expression in myelodysplastic syndromes (MDS), CD34+ cells from 24 patients with RARS, as well as cells from 20 patients with refractory anemia (RA) and from 8 healthy donors (as control groups) were cultured. Cytospins were performed for MtF, H-ferritin (HF) and L-ferritin (LF) immunocytochemical analysis, and samples of cultured cells were removed at various days of culture for biological studies. Lentivirus-mediated FTMT transduction of normal CD34+ progenitors did not inhibit cell growth nor prevent the differentiation of erythroid progenitors. By flow cytometry analysis, MtF-positive erythroid progenitors showed significantly reduced levels of HF and increased expression of transferrin receptor (CD71) compared with MtF-negative progenitors (P = .004 and P = .01, respectively). In this model, induction of MtF resulted in increased cellular apoptosis (median number of apoptotic cells by TUNEL assay at day 21 equal to 83% in MtF-positive cells vs 18% in MtF-negative cells, P < .001). A significantly lower proliferation rate and higher apoptotic index were observed in cultures from patients with RARS and RA with respect to healthy controls. FTMT mRNA was detected by RT-PCR in CD34+ progenitor cells from patients with RARS, while protein expression was observed only from day 4 of culture, with a significant increase in the percentage of MtF-positive cells during culture (median value from 5% at day 4 to 24% at day 21, P = .002). No MtF expression was observed in RA patients. In MtF-positive cells from RARS patients, an inverse relationship between MtF and HF cellular content, and a direct relationship between MtF and CD71 expression were observed. In erythroid progenitors from RARS patients, the apoptotic rate was higher in MtF-positive than in MtF-negative cells (median number of apoptotic cells equal to 17% vs 6%, P < .001). Finally, we analyzed by flow cytometry the relationship between MtF expression and STAT5 phosphorylation in cultured cells following Epo stimulation. Preliminary data from three RARS patients showed that p-STAT5 expression was lower in MtF-positive than in MtF-negative cells (P = .02). In conclusion, experimental overexpression of MtF in normal erythroid progenitors may reduce mitochondrial iron availability thus inducing apoptosis. In erythroid progenitors from RARS patients, the pathological expression of MtF is associated with increased apoptosis of immature red cells (ineffective erythropoiesis), which may be at least in part determined by reduced activation of the JAK-STAT pathway in response to Epo. Disclosures: No relevant conflicts of interest to declare.
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Ilias, Ioannis, Manfredi Rizzo, and Lina Zabuliene. "Metformin: Sex/Gender Differences in Its Uses and Effects—Narrative Review." Medicina 58, no. 3 (March 16, 2022): 430. http://dx.doi.org/10.3390/medicina58030430.
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Metformin (MTF) occupies a major and fundamental position in the therapeutic management of type 2 diabetes mellitus (T2DM). Gender differences in some effects and actions of MTF have been reported. Women are usually prescribed lower MTF doses compared to men and report more gastrointestinal side effects. The incidence of cardiovascular events in women on MTF has been found to be lower to that of men on MTF. Despite some promising results with MTF regarding pregnancy rates in women with PCOS, the management of gestational diabetes, cancer prevention or adjunctive cancer treatment and COVID-19, most robust meta-analyses have yet to confirm such beneficial effects.
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Gentil, Paulo, Elke Oliveira, Keila Fontana, Guilherme Molina, Ricardo Jacó de Oliveira, and Martim Bottaro. "Efeitos agudos de vários métodos de treinamento de força no lactato sanguíneo e características de cargas em homens treinados recreacionalmente." Revista Brasileira de Medicina do Esporte 12, no. 6 (December 2006): 303–7. http://dx.doi.org/10.1590/s1517-86922006000600001.
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Diversos métodos de treinamento de força (MTF) foram desenvolvidos com o propósito de manipular os estímulos fisiológicos e obter melhores resultados com o treinamento. O propósito do presente estudo foi comparar as respostas metabólicas e mecânicas entre sete diferentes MTF descritos na literatura. Os MTF foram comparados com relação ao lactato sanguíneo, tempo sob tensão (TST) e sobrecarga total (TST x carga) em jovens treinados do sexo masculino. Os MTF testados foram 10RM, superlento, isométrico funcional, oclusão vascular adaptada, 6RM, repetições forçadas e séries descendentes. Todos os MTF produziram elevações significativas no lactato sanguíneo, sem diferenças entre eles. O método de séries descendentes produziu maior tempo sob tensão e sobrecarga total em comparação com os outros MTF testados.
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Carellas, Peter T., and Stephen D. Fantone. "Why measure MTF?" Optics and Photonics News 1, no. 6 (June 1, 1990): 27. http://dx.doi.org/10.1364/opn.1.6.000027.
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Lu, Lu, Carol Ho-Yan Fong, Anna Jinxia Zhang, Wai-Lan Wu, Iris Can Li, Andrew Chak-Yiu Lee, Thrimendra Kaushika Dissanayake, et al. "Repurposing of Miltefosine as an Adjuvant for Influenza Vaccine." Vaccines 8, no. 4 (December 11, 2020): 754. http://dx.doi.org/10.3390/vaccines8040754.
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We previously reported that topical imiquimod can improve the immunogenicity of the influenza vaccine. This study investigated another FDA-approved drug, miltefosine (MTF), as a vaccine adjuvant. Mice immunized with an influenza vaccine with or without MTF adjuvant were challenged by a lethal dose of influenza virus 3 or 7 days after vaccination. Survival, body weight, antibody response, histopathological changes, viral loads, cytokine levels, and T cell frequencies were compared. The MTF-adjuvanted vaccine (MTF-VAC) group had a significantly better survival rate than the vaccine-only (VAC) group, when administered 3 days (80% vs. 26.7%, p = 0.0063) or 7 days (96% vs. 65%, p = 0.0041) before influenza virus challenge. Lung damage was significantly ameliorated in the MTF-VAC group. Antibody response was significantly augmented in the MTF-VAC group against both homologous and heterologous influenza strains. There was a greater T follicular helper cell (TFH) response and an enhanced germinal center (GC) reaction in the MTF-VAC group. MTF-VAC also induced both TH1 and TH2 antigen-specific cytokine responses. MTF improved the efficacy of the influenza vaccine against homologous and heterologous viruses by improving the TFH and antibody responses. Miltefosine may also be used for other vaccines, including the upcoming vaccines for COVID-19.
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Andéol, Yannick, Jessica Bonneau, Laurence M. Gagné, Kevin Jacquet, Véronique Rivest, Marc-Étienne Huot, and Carl Séguin. "The phosphoinositide 3-kinase pathway and glycogen synthase kinase-3 positively regulate the activity of metal-responsive transcription factor-1 in response to zinc ions." Biochemistry and Cell Biology 96, no. 6 (December 2018): 726–33. http://dx.doi.org/10.1139/bcb-2018-0073.
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Metal-responsive transcription factor-1 (MTF-1) is a metal-regulatory transcription factor essential for induction of the genes encoding metallothioneins (MTs) in response to transition metal ions. Activation of MTF-1 is dependent on the interaction of zinc with the zinc fingers of the protein. In addition, phosphorylation is essential for MTF-1 transactivation. We previously showed that inhibition of phosphoinositide 3-kinase (PI3K) abrogated Mt expression and metal-induced MTF-1 activation in human hepatocellular carcinoma (HCC) HepG2 and mouse L cells, thus showing that the PI3K signaling pathway positively regulates MTF-1 activity and Mt gene expression. However, it has also been reported that inhibition of PI3K has no significant effects on Mt expression in immortalized epithelial cells and increases Mt expression in HCC cells. To further characterize the role of the PI3K pathway on the activity of MTF-1, transfection experiments were performed in HEK293 and HepG2 cells in presence of glycogen synthase kinase-3 (GSK-3), mTOR–C1, and mTOR–C2 inhibitors, as well as of siRNAs targeting Phosphatase and TENsin homolog (PTEN). We showed that inhibition of the mTOR–C2 complex inhibits the activity of MTF-1 in HepG2 and HEK293 cells, while inhibition of the mTOR–C1 complex or of PTEN stimulates MTF-1 activity in HEK293 cells. These results confirm that the PI3K pathway positively regulates MTF-1 activity. Finally, we showed that GSK-3 is required for MTF-1 activation in response to zinc ions.
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Ruiz-Robles, Dante, Edgar L. Moreno-Goytia, Vicente Venegas-Rebollar, and Nadia M. Salgado-Herrera. "Power Density Maximization in Medium Frequency Transformers by Using Their Maximum Flux Density for DC–DC Converters." Electronics 9, no. 3 (March 11, 2020): 470. http://dx.doi.org/10.3390/electronics9030470.
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The medium frequency transformer (MTF) is a key component of various new DC–DC converters that are designed for applications in modern electrical power grids at medium and high voltage. To attain the high performance that are necessary for targeting these applications, MFTs should have high power density and high efficiency as characteristics. For this endeavor, newly designed MFT procedures, which also take advantages of new core materials, are under investigation. Differently to other design proposals, most of which use conventional transformer design procedures based on equating core losses to copper conduction losses, in this paper, an MTF with a nanocrystalline (VITROPERM 500F) core is designed with a new procedure that is oriented in aiming the maximum flux density (Bmax). The characteristics of the MFTs that are obtained by using this procedure are compared with those of the MFTFs that are designed with a conventional procedure. The results show that by using the proposed technique, we get a 25% reduction in the winding size, a higher power density, and a lower MTF building cost while maintaining a high efficiency (>98%). The design methodology is developed through a rigorous mathematical analysis that is verified with computer simulations in Matlab-Simulink and validated with experimental results from two MTF laboratory prototypes designed at a flux density of 0.9 T (75% Bmax) and 1.2 T (Bmax).
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Panfoli, Isabella, Alessandra Puddu, Nadia Bertola, Silvia Ravera, and Davide Maggi. "The Hormetic Effect of Metformin: “Less Is More”?" International Journal of Molecular Sciences 22, no. 12 (June 11, 2021): 6297. http://dx.doi.org/10.3390/ijms22126297.
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Metformin (MTF) is the first-line therapy for type 2 diabetes (T2DM). The euglycemic effect of MTF is due to the inhibition of hepatic glucose production. Literature reports that the principal molecular mechanism of MTF is the activation of 5′-AMP-activated protein kinase (AMPK) due to the decrement of ATP intracellular content consequent to the inhibition of Complex I, although this effect is obtained only at millimolar concentrations. Conversely, micromolar MTF seems to activate the mitochondrial electron transport chain, increasing ATP production and limiting oxidative stress. This evidence sustains the idea that MTF exerts a hormetic effect based on its concentration in the target tissue. Therefore, in this review we describe the effects of MTF on T2DM on the principal target organs, such as liver, gut, adipose tissue, endothelium, heart, and skeletal muscle. In particular, data indicate that all organs, except the gut, accumulate MTF in the micromolar range when administered in therapeutic doses, unmasking molecular mechanisms that do not depend on Complex I inhibition.
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Wahyuni, S., I. Antasionasti, A. Khaeruni, P. A. Priscilla, M. Pitunani, and N. D. P. Dewi. "Modification of Tannia (Xanthoxoma sagittifolium) Starch using Lactic Acid Bacteria and Its Application for Cookies Products." Asian Journal of Chemistry 32, no. 4 (February 25, 2020): 753–58. http://dx.doi.org/10.14233/ajchem.2020.22336.
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This work was performed to evaluate the physico-chemical properties of modified tannia flour (MTF) with lactic acid bacteria. Physico-chemical properties of MTF by analyzing the degree of acidity, swelling power and solubility, functional group analysis by FTIR and XRD patterns, then determine proximate composition of MTF cookies. Modified tannia flour is indicated by intensity decreased of the FTIR and XRD patterns during fermentation. Proximate composition of MTF and cookies with moisture, ash, fat, protein and glucose content products approximately, respectively 7.63 ± 0.05 %, 2.94 ± 0.02 %, 0.01 ± 0.21 %, 0.86 ± 0.09 %, 43.00 ± 0.14 % and 8.76 ± 0.22 %, 2.67 ± 1.18 %, 48.07 ± 0.23 %, 16.52 ± 0.03 %, 9.08 ± 1.77 %. Physico-chemical properties of MTF with lactic acid bacteria had pH of MTF decreased but swelling power and solubility increased during fermentation and pasting characteristics were modified, so MTF can be applied for making cookies product, where the addition of anchovy meat as a source of protein can increase the protein content of cookies product.
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Thom, George, Mei-Mei Tian, Jon P. Hatcher, Natalia Rodrigo, Matthew Burrell, Ian Gurrell, Timothy Z. Vitalis, et al. "A peptide derived from melanotransferrin delivers a protein-based interleukin 1 receptor antagonist across the BBB and ameliorates neuropathic pain in a preclinical model." Journal of Cerebral Blood Flow & Metabolism 39, no. 10 (May 30, 2018): 2074–88. http://dx.doi.org/10.1177/0271678x18772998.
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Delivery of biologic drugs across the blood–brain barrier is becoming a reality. However, the solutions often involve the assembly of complex multi-specific antibody molecules. Here we utilize a simple 12 amino-acid peptide originating from the melanotransferrin (MTf) protein that has shown improved brain delivery properties. 3D confocal fluorescence microscopic analysis demonstrated brain parenchymal localisation of a fluorescently labelled antibody (NIP228) when chemically conjugated to either the MTf peptide or full-length MTf protein. Measurement of plasma kinetics demonstrated the MTf peptide fusions had very similar kinetics to an unmodified NIP228 control antibody, whereas the fusion to MTf protein had significantly reduced plasma exposure most likely due to a higher tissue distribution in the periphery. Brain exposure for the MTf peptide fusions was significantly increased for the duration of the study, exceeding that of the fusions to full length MTf protein. Using a neuropathic pain model, we have demonstrated that fusions to interleukin-1 receptor antagonist (IL-1RA) are able to induce significant and durable analgesia following peripheral administration. These data demonstrate that recombinant and chemically conjugated MTf-based brain delivery vectors can deliver therapeutic levels of drug to the central nervous system.
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Othman, Shah Farez, Nizam Tamchek, Farah Diana Muhammad, and Mohd Hafidz Ithnin. "Modulation Transfer Function Analysis in Myopic Model Eye." ASM Science Journal 16 (July 15, 2021): 1–8. http://dx.doi.org/10.32802/asmscj.2021.688.
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Hitherto, the eye modelling is based on the emmetropic eye taken its ocular optical components value from the population-based studies. However, no studies have been done to study the effect of aberration of myopic refractive error by modelling the eye using the parameters from ocular biometrics and ray tracing method. This study aimed to determine the modulation transfer function (MTF) of myopic refractive error using eye modelling and ray tracing technique. Three eye models had been successfully modelled in Zemax software, namely, emmetropic Liou and Brennan, myopic Liou and Brennan, corrected myopic Liou and Brennan. The optical performance of the eye models were tested using the MTF. From the MTF analysis at 100 cycles/mm, the MTF value of both tangential and sagittal rays for myopic Liou and Brennan eye was the lowest compared to its emmetropic model. Also, the MTF value of the corrected myopic Liou and Brennan model was higher compared to the uncorrected myopic model. However, the corrected myopic model produced lower MTF values for both tangential and sagittal MTF compared with the emmetropic model of Liou and Brennan. In this study, the accuracy of the MTF for myopia correction and emmetropia were calculated. It was found that the accuracy of the MTF value for corrected myopia at tangential and sagittal rays was lower.
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Dubé, Annie, Jean-François Harrisson, Geneviève Saint-Gelais, and Carl Séguin. "Hypoxia acts through multiple signaling pathways to induce metallothionein transactivation by the metal-responsive transcription factor-1 (MTF-1)." Biochemistry and Cell Biology 89, no. 6 (December 2011): 562–77. http://dx.doi.org/10.1139/o11-063.
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Metal-responsive transcription factor-1 (MTF-1) is essential for the induction of genes encoding metallothionein by metals and hypoxia. Here, we studied the mechanism controlling the activation of MTF-1 by hypoxia. Hypoxia activation of Mt gene transcription is dependent on the presence of metal regulatory elements (MREs) in the promoter of Mt genes. We showed that MREa and MREd are the main elements controlling mouse Mt-1 gene induction by hypoxia. Transfection experiments in Mtf-1-null cells showed that MTF-1 is essential for induction by hypoxia. Chromatin immunoprecipitation analysis showed that MTF-1 DNA-binding activity was strongly enhanced in the presence of zinc but not by hypoxia. Notably, hypoxia inducible factor- (HIF) 1α was recruited to the Mt-1 promoter in response to hypoxia but not to zinc. MTF-1 activation was inhibited by PKC, JNK, and PI3K inhibitors and by the electron transport chain inhibitors rotenone and myxothiazol, but not by the antioxidant N-acetylcysteine. We showed that prolyl-hydroxylase inhibitors can activate MTF-1, but this activation requires the presence of HIF-1α. Finally, HIF-dependent transcription is enhanced in the presence of MTF-1 and induction of an MRE promoter is stimulated by HIF-1α, thus indicating cooperation between these 2 factors. However, coimmunoprecipitation experiments did not suggest direct interaction between MTF-1 and HIF-1α.
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Schake, Markus, and Michael Schulz. "Influence of camera temperature on MTF measurements with finite image distance." EPJ Web of Conferences 266 (2022): 10018. http://dx.doi.org/10.1051/epjconf/202226610018.
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Line Spread Function (LSF) based Modulation Transfer Function (MTF) measurements with finite image distance are sensitive to displacement errors in axial direction. Axial displacements between the sample and camera detector cause defocusing and thus, a MTF error proportional to the axial gradient of the sample’s MTF. This article demonstrates the influence of the camera temperature on the focus position in the MTF reference setup at PTB.
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Georgiev, Oleg, Viola Günther, Kurt Steiner, Katharina Schönrath, and Walter Schaffner. "The legless lizard Anguis fragilis (slow worm) has a potent metal-responsive transcription factor 1 (MTF-1)." Biological Chemistry 395, no. 4 (April 1, 2014): 425–31. http://dx.doi.org/10.1515/hsz-2013-0293.
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Abstract The metal-responsive transcription factor-1 (MTF-1) is a key regulator of heavy metal homeostasis and detoxification. Here we characterize the first MTF-1 from a reptile, the slow worm Anguis fragilis. The slow worm, or blind worm, is a legless lizard also known for its long lifespan of up to several decades. Anguis MTF-1 performs well and matches the strong zinc and cadmium response of its human ortholog, clearly surpassing the activity of rodent MTF-1s. Some amino acid positions critical for metal response are the same in humans and slow worm but not in rodent MTF-1. This points to a divergent evolution of rodent MTF-1, and we speculate that rodents can afford a less sophisticated metal handling than humans and (some) reptiles.
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FERREIRA, RULFE TAVARES, ALEXANDRE PIO VIANA, FERNANDO HIGINO DE LIMA E. SILVA, EILEEN AZEVEDO SANTOS, and JARDEL OLIVEIRA SANTOS. "SELEÇÃO RECORRENTE INTRAPOPULACIONAL EM MARACUJAZEIRO-AZEDO VIA MODELOS MISTOS." Revista Brasileira de Fruticultura 38, no. 1 (February 2016): 158–66. http://dx.doi.org/10.1590/0100-2945-260/14.
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RESUMO O maracujazeiro pertence ao gênero Passiflora, considerado o de maior importância econômica da família Passifloraceae. O objetivo do trabalho foi estimar para o maracujazeiro-azedo parâmetros e valores genotípicos pelo procedimento REML/BLUP em nível de progênie. Foram avaliadas 27 progênies de meios-irmãos oriundas do segundo ciclo de seleção recorrente conduzido na UENF, selecionadas via índice de seleção. As características avaliadas foram: número de frutos por parcela (NF); massa total de frutos por parcela (MTF) e massa média de frutos (MMF). Os valores genéticos foram estimados por meio do Software SELEGEN, utilizando o procedimento REML/BLUP. Nas estimativas dos parâmetros genéticos via REML, as duas características ligadas diretamente à produção e, portanto, consideradas as mais importantes, NF e MTF apresentaram estimativas de herdabilidade média de progênies de 0,395 e 0,439, respectivamente. Na seleção e nas estimativas dos ganhos via BLUP, o coeficiente de coincidência revelou concordância do resultado da seleção entre as progênies, mostrando que para as três características avaliadas, as mesmas 8 progênies são superiores para as três características simultaneamente. A metodologia REML/BLUP mostrou-se adequada para a avaliação, possibilitando obter estimativas dos parâmetros genéticos e fenotípicos que revelaram a possibilidade de sucesso com a seleção de progênies superiores, com ganhos simultaneamente de 18,02%, 23,08% e 9,65% para NF, MTF e MMF, respectivamente.
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Li, Yong, Tomoki Kimura, John H. Laity, and Glen K. Andrews. "The Zinc-Sensing Mechanism of Mouse MTF-1 Involves Linker Peptides between the Zinc Fingers." Molecular and Cellular Biology 26, no. 15 (August 1, 2006): 5580–87. http://dx.doi.org/10.1128/mcb.00471-06.
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ABSTRACT Mouse metal response element-binding transcription factor-1 (MTF-1) regulates the transcription of genes in response to a variety of stimuli, including exposure to zinc or cadmium, hypoxia, and oxidative stress. Each of these stresses may increase labile cellular zinc, leading to nuclear translocation, DNA binding, and transcriptional activation of metallothionein genes (MT genes) by MTF-1. Several lines of evidence suggest that the highly conserved six-zinc finger DNA-binding domain of MTF-1 also functions as a zinc-sensing domain. In this study, we investigated the potential role of the peptide linkers connecting the four N-terminal zinc fingers of MTF-1 in their zinc-sensing function. Each of these three linkers is unique, completely conserved among all known vertebrate MTF-1 orthologs, and different from the canonical Cys2His2 zinc finger TGEKP linker sequence. Replacing the RGEYT linker between zinc fingers 1 and 2 with TGEKP abolished the zinc-sensing function of MTF-1, resulting in constitutive DNA binding, nuclear translocation, and transcriptional activation of the MT-I gene. In contrast, swapping the TKEKP linker between fingers 2 and 3 with TGEKP had little effect on the metal-sensing functions of MTF-1, whereas swapping the canonical linker for the shorter TGKT linker between fingers 3 and 4 rendered MTF-1 less sensitive to zinc-dependent activation both in vivo and in vitro. These observations suggest a mechanism by which physiological concentrations of accessible cellular zinc affect MTF-1 activity. Zinc may modulate highly specific, linker-mediated zinc finger interactions in MTF-1, thus affecting its zinc- and DNA-binding activities, resulting in translocation to the nucleus and binding to the MT-I gene promoter.
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Nishimoto, Fumihito, Masahiro Sakata, Ryoko Minekawa, Yoko Okamoto, Asako Miyake, Aki Isobe, Toshiya Yamamoto, et al. "Metal Transcription Factor-1 Is Involved in Hypoxia-Dependent Regulation of Placenta Growth Factor in Trophoblast-Derived Cells." Endocrinology 150, no. 4 (November 20, 2008): 1801–8. http://dx.doi.org/10.1210/en.2008-0949.
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Placenta growth factor (PlGF) is a placental angiogenic factor. Metal-responsive transcription factor (MTF)-1 was reported to take part in the hypoxic induction of PlGF in RAS-transformed mouse fibroblasts. We contrarily showed that PlGF mRNA and protein levels decreased under hypoxia in a choriocarcinoma BeWo cell line derived from trophoblast. In this report, we examined whether hypoxia-dependent regulation of the PlGF gene in these cells also depends on MTF-1. We analyzed the effect of hypoxia on MTF-1 expression, and it was revealed to be decreased. Moreover, MTF-1 small interfering RNA treatment decreased PlGF mRNA level. To investigate the transcription of PlGF under hypoxia, we cloned promoter region of the human PlGF. Promoter deletion analysis suggested that triple repeats of metal-responsive element located between −511 and −468 bp in the promoter are important for the hypoxic regulation of PlGF. Treatment with MTF-1 small interfering RNA resulted in the significant decreased luciferase activity in PlGF reporter constructs. Chromatin immunoprecipitation showed the binding of the MTF-1 protein to the promoter region. We examined MTF-1 immunoreactivity in trophoblasts of term placental tissue from patients with normal pregnancies and preeclampsia, which represents a condition of placental hypoxia. Immunoreactivity of the MTF-1 protein was decreased in placentas from pregnant women with preeclampsia when compared with those from normal pregnant women. Taken together, these findings suggest that MTF-1 is involved in hypoxia-dependent regulation of PlGF in trophoblast-derived cells.
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Lin, Meng-Chieh, Ya-Chuan Liu, Ming F. Tam, Yu-Ju Lu, Ya-Ting Hsieh, and Lih-Yuan Lin. "PTEN interacts with metal-responsive transcription factor 1 and stimulates its transcriptional activity." Biochemical Journal 441, no. 1 (December 14, 2011): 367–77. http://dx.doi.org/10.1042/bj20111257.
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MTF-1 (metal-responsive transcription factor 1) is an essential mammalian protein for embryonic development and modulates the expression of genes involving in zinc homoeostasis and responding to oxidative stress. We report in the present paper that PTEN (phosphatase and tensin homologue deleted on chromosome 10) associates with MTF-1 in the cells. These two proteins interact via the acidic domain of MTF-1 and the phosphatase/C2 domain of PTEN. Depletion of PTEN reduced MT (metallothionein) gene expression and increased cellular sensitivity to cadmium toxicity. PTEN did not alter the nuclear translocation, protein stability or DNA-binding activity of MTF-1. Zinc increased MTF-1–PTEN interaction in a dose-dependent manner. The interaction elevated within 2 h of zinc addition and declined afterwards in the cells. The enhanced binding activity occurred mainly in the cytoplasm and reduced after translocating the MTF-1 into the nucleus. Blocking signalling through the PI3K (phosphoinositide 3-kinase) pathway did not alter the zinc-induced MT expression. Analysis of enzymatically inactive PTEN mutants demonstrated that protein but not lipid phosphatase activity of PTEN was involved in the regulation of MTF-1 activity. The same regulatory role of PTEN was also noted in the regulation of ZnT1 (zinc transporter 1), another target gene of MTF-1.
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Cervantes, Jorge L., Angel Sanca, and Jose Barragan. "Metformin effect on human macrophage inflammatory response and phagocytosis of Mycobacterium tuberculosis." Journal of Immunology 204, no. 1_Supplement (May 1, 2020): 73.9. http://dx.doi.org/10.4049/jimmunol.204.supp.73.9.
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Abstract Metformin (MTF) has a well-documented ability to cfontrol hyperglycemia, which has been shown to have effects on macrophage and lymphocyte functions that are key to controlling tuberculosis (TB) infection. Here, we aimed to better understand the effects of MTF on the phagocytosis of Mycobacterium tuberculosis (Mtb) by human macrophages. PMA-differentiated THP-1 cells with two reporters for nuclear factor-κB (NF-κB), and interferon-regulatory factors (IRFs) were treated with 2mM of MTF for 4 hours, and then inoculated with Mtb from various lineages. Since MTF can also directly inhibit key metabolic processes of Mtb, we controlled this variable by using of gamma-irradiated mycobacteria. Phagocytosis was assessed by immunofluorescent assay. Phagocytosis of Mtb increased in MTF-treated macrophages. NF-κB activation after Mtb stimulation was lower in MTF-treated macrophages. The effect on IRF activation was minimal. Our results indicate that MTF improves phagocytosis of Mtb by macrophages, while it at the same time modulating their inflammatory response. Downregulation of type I IFN pathways, associated with active TB infection, could allow for improved activation of macrophages in the presence of TB infection. These results support the effects of MTF in keys steps TB infection control, and support its use as an additional treatment for TB.
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Xu, Yan, Gu, Li, and Li. "Analysis of Dynamic Modulation Transfer Function for Complex Image Motion." Applied Sciences 9, no. 23 (November 27, 2019): 5142. http://dx.doi.org/10.3390/app9235142.
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In remote-sensing imaging, the modulation transfer function (MTF) for image motion relevant to the mixing of multiple forms of motions is hard to calculate because of the complicated image motion expression. In this paper, a new method for calculating the MTF for complex image motion is proposed. The presented method makes it possible to obtain an analytical MTF expression derived from the mixing of linear motion and sinusoidal motion at an arbitrary frequency. On this basis, we used the summation of infinitely many terms involving the Bessel function to simplify the MTF expression. The truncation error obtained by the use of finite order sum approximations instead of infinite sums is investigated in detail. In order to verify the MTF calculation method, we proposed a simulation method to calculate the variation of MTF in an actual optical system caused by image motion. The mean value of the relative error between the calculation method and the simulation method is less than 5%. The experimental results are consistent with the MTF curve calculated by our method.
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Eskin, Fatih, and Duygu Tutan. "Is there a relationship between metformin-related gastrointestinal symptoms and vitamin B12 deficiency in patients with type 2 diabetes mellitus?" Medicine Science | International Medical Journal 12, no. 1 (2023): 324. http://dx.doi.org/10.5455/medscience.2023.02.025.
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Metformin (MTF) associated gastrointestinal symptoms are fairly common side effects that adversely affect patients' treatment adherence. However, the variability of gastrointestinal symptoms in MTF-using patients has not been fully explained. In our study, we aimed to investigate the relationship between vitamin B12 deficiency with MTF-related gastrointestinal symptoms. Patients with type 2 diabetes mellitus (T2DM) using MTF were included in the study sequentially. Demographic characteristics of the patients, duration of diabetes, MTF dose and duration used, and gastrointestinal symptoms were recorded. Afterward, a hemogram, HgbA1c, and vitamin B12 measurements were performed. Patients with and without vitamin B12 deficiency were divided into two groups. The two groups were compared with statistical methods. Twenty-five percent of patients had low serum vitamin B12 levels. Patients with vitamin B12 deficiency had a longer diabetes duration, and a longer MTF usage duration (p<0.001, p<0.001) than the patients without vitamin B12 deficiency. There was no correlation between B12 deficiency and MTF dosage (p=0.590). Gastrointestinal symptoms were seen more frequently in the B12 deficiency group (p=0.025). Bloating and constipation, nausea, abdominal pain, and vomiting were seen commonly in the B12 deficiency group (p=0.002, p<0.001, p=0.014, p=0.004, respectively). Three or more symptoms were frequently seen in B12-deficient patients (p<0.001). Patients with both a MTF usage duration of 10 years or higher and vitamin B12 deficiency are found to be 434% more likely to have active gastrointestinal symptoms than all other patient groups (OR:5.343, 95%CI (2.173-13.140), p<0.001). Study results have shown that gastrointestinal symptoms seen in patients with T2DM taking MTF may be associated with vitamin B12 deficiency. MTF-related gut microbiome changes may play a role in this relationship. In particular, we recommend that patients who have been using MTF for ≥10 years and have gastrointestinal complaints should be followed more closely for vitamin B12 deficiency.
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Schulten, Hans-Juergen. "Pleiotropic Effects of Metformin on Cancer." International Journal of Molecular Sciences 19, no. 10 (September 20, 2018): 2850. http://dx.doi.org/10.3390/ijms19102850.
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Metformin (MTF) is a natural compound derived from the legume Galega officinalis. It is the first line antidiabetic drug for type 2 diabetes (T2D) treatment. One of its main antidiabetic effects results from the reduction of hepatic glucose release. First scientific evidence for the anticancer effects of MTF was found in animal research, published in 2001, and some years later a retrospective observational study provided evidence that linked MTF to reduced cancer risk in T2D patients. Its pleiotropic anticancer effects were studied in numerous in vitro and in vivo studies at the molecular and cellular level. Although the majority of these studies demonstrated that MTF is associated with certain anticancer properties, clinical studies and trials provided a mixed view on its beneficial anticancer effects. This review emphasizes the pleiotropic effects of MTF and recent progress made in MTF applications in basic, preclinical, and clinical cancer research.
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Song, Yu Long. "A Precise MTF Measurement Method of Programmable Optical Systems." Key Engineering Materials 552 (May 2013): 497–501. http://dx.doi.org/10.4028/www.scientific.net/kem.552.497.
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The programmable coded aperture has been applied to the optical systems to enhance their functionality and performance. Therefore, the optical system is programmable. It means that the optical system could be changed momentarily. Conventionally, during MTF measurement, the optical system is fixed. The system under test and the test equipment have no relation of time- sequence. The image sensor sample of test equipment can be random. But In the programmable optical system, the aperture style and its duration in a frame period have a impact on the system MTF. Conventional MTF measurement methods can’t be used to test accurately the MTF of programmable optical system. In this paper, we propose a method and design a system which can test precisely MTF of the programmable optical system. In this method the sample of a sensor would be synchronized with the coded aperture program logic, which ensures the precision of MTF measurement.
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Garcia, Maria-Gabriela, Rudolf Wall, Benjamin Steinhilber, Thomas Läubli, and Bernard J. Martin. "Long-Lasting Changes in Muscle Twitch Force During Simulated Work While Standing or Walking." Human Factors: The Journal of the Human Factors and Ergonomics Society 58, no. 8 (September 27, 2016): 1117–27. http://dx.doi.org/10.1177/0018720816669444.
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Objective: The aim of this study was to evaluate the long-lasting effects of prolonged standing work on a hard floor or floor mat and slow-pace walking on muscle twitch force (MTF) elicited by electrical stimulation. Background: Prolonged standing work may alter lower-leg muscle function, which can be quantified by changes in the MTF amplitude and duration related to muscle fatigue. Ergonomic interventions have been proposed to mitigate fatigue and discomfort; however, their influences remain controversial. Method: Ten men and eight women simulated standing work in 320-min experiments with three conditions: standing on a hard floor or an antifatigue mat and walking on a treadmill, each including three seated rest breaks. MTF in the gastrocnemius-soleus muscles was evaluated through changes in signal amplitude and duration. Results: The significant decrease of MTF amplitude and an increase of duration after standing work on a hard floor and on a mat persisted beyond 1 hr postwork. During walking, significant MTF metrics changes appeared 30 min postwork. MTF amplitude decrease was not significant after the first 110 min in any of the conditions; however, MTF duration was significantly higher than baseline in the standing conditions. Conclusion: Similar long-lasting weakening of MTF was induced by standing on a hard floor and on an antifatigue mat. However, walking partially attenuated this phenomenon. Application: Mostly static standing is likely to contribute to alterations of MTF in lower-leg muscles and potentially to musculoskeletal disorders regardless of the flooring characteristics. Occupational activities including slow-pace walking may reduce such deterioration in muscle function.
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Balamurugan, K., D. Egli, A. Selvaraj, B. Zhang, O. Georgiev, and W. Schaffner. "Metal-responsive transcription factor (MTF-1) and heavy metal stress response in Drosophila and mammalian cells: a functional comparison." Biological Chemistry 385, no. 7 (July 5, 2004): 597–603. http://dx.doi.org/10.1515/bc.2004.074.
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AbstractThe zinc finger transcription factor MTF-1 (metalresponsive transcription factor-1) is conserved from insects to vertebrates. Its major role in both organisms is to control the transcription of genes involved in the homeostasis and detoxification of heavy metal ions such as Cu[2+], Zn[2+] and Cd [2+]. In mammals, MTF-1 serves at least two additional roles. First, targeted disruption of the MTF-1 gene results in death at embryonic day 14 due to liver degeneration, revealing a stagespecific developmental role. Second, under hypoxicanoxic stress, MTF-1 helps to activate the transcription of the gene placental growth factor (PlGF), an angiogenic protein. Recently we characterized dMTF-1, theDrosophilahomolog of mammalian MTF-1. Here we present a series of studies to compare the metal response in mammals and insects, which reveal common features but also differences. A human MTF-1 transgene can restore to a large extent metal tolerance to flies lacking their own MTF-1 gene, both at low and high copper concentrations. Likewise,DrosophilaMTF-1 can substitute for human MTF-1 in mammalian cell culture, although both the basal and the metalinduced transcript levels are lower. Finally, a clear difference was revealed in the response to mercury, a highly toxic heavy metal: metallothioneintype promoters respond poorly, if at all, to Hg[2+] in mammalian cells but strongly inDrosophila, and this response is completely dependent on dMTF-1.
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Rodgers, J. R., R. Smith, and R. R. Rich. "Maternally transmitted antigens are codominantly expressed by mouse cells containing two kinds of mitochondrial DNA." Journal of Experimental Medicine 165, no. 2 (February 1, 1987): 560–65. http://dx.doi.org/10.1084/jem.165.2.560.
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Mtf, a cytoplasmic, probably mitochondrial factor, controls Mta polymorphism. We tested for dominance between two forms of Mtf to determine whether Mta is controlled by positive or negative genetic mechanisms. We fused Mtf-disparate cells containing distinct mtDNA markers and selected for hybrids containing both. Such mtDNA heteroplasmons codominantly and stably express alternative Mta antigens. Stable codominance excludes negative genetic mechanisms as well as a model of induced nuclear compensation, and implies Mtf controls Mta expression through a positive genetic mechanism.
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Yuan, Yuan, Yao Hua Yi, and Min Jing Miao. "An Automatic Calculation Method of MTF and the Application in Blurred Images Restoration." Applied Mechanics and Materials 731 (January 2015): 141–46. http://dx.doi.org/10.4028/www.scientific.net/amm.731.141.
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Modulation transfer function (MTF) is a comprehensive index for the objective reflection of the quality of the imaging systems. In the field of image processing, the slanted-edge method is usually adopted to compute MTF for images. However, the sub-images with slanted edges are extracted from original image by subjective judgment and manually operation, which is bound to lead to inefficiency of calculation, low accuracy and instability of results with the participation of humans. Aiming at the above problem, this paper presents an automatic MTF calculation method for blurred images and applies it to the process of image restoration by developing a two-dimensional MTF filter and utilizing it into conventional restoration methods such as the Wiener filtering, least squares filtering and Lucy-Richardson algorithm. Experiment results indicate the proposed method achieved an automatic, fast and accurate MTF computation for blurred images, and MTF-based restoration methods were superior to traditional ones in restoration effects.
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Oróstica, Maria Lorena, Isis Astorga, Francisca Plaza-Parrochia, Cristian Poblete, Rodrigo Carvajal, Víctor García, Carmen Romero, and Margarita Vega. "Metformin Treatment Regulates the Expression of Molecules Involved in Adiponectin and Insulin Signaling Pathways in Endometria from Women with Obesity-Associated Insulin Resistance and PCOS." International Journal of Molecular Sciences 23, no. 7 (April 1, 2022): 3922. http://dx.doi.org/10.3390/ijms23073922.
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Polycystic ovary syndrome (PCOS) is an endocrine/metabolic disorder associated with insulin resistance (IR) and obesity. Endometria from women with PCOS present failures in insulin action, glucose uptake and signaling of insulin-sensitizing molecules, such as adiponectin, with consequences for reproduction. Metformin (MTF) treatment improves insulin signaling in endometrial tissues, but its mechanism is not fully understood. This study addresses the MTF effect, as well as adiponectin agonist action, on levels of molecules associated with insulin and adiponectin signaling pathways in endometrial tissue and cells, as assessed by immunohistochemistry and immunocytochemistry, respectively. Endometrial tissues were obtained from women and divided into five groups: Normal Weight (control); Obesity + IR; Obesity + IR + PCOS; Obesity + IR + MTF; Obesity + IR + PCOS + MTF. Endometrial cells stimulated with TNFα (as obesity-marker) were also used to partially emulate an obesity environment. The results showed low levels of insulin/adiponectin signaling in the endometria from women with obesity, IR and PCOS compared with the control group. MTF re-established these levels, independently of PCOS. TNFα-associated molecules were elevated in pathologic endometria, whereas MTF diminished these levels. The low levels of insulin/adiponectin molecules in endometrial cells treated with TNFα were reverted by MTF, similar to what was observed in the case of the adiponectin agonist. Therefore, independently of PCOS, MTF can re-establish levels of molecules involved in insulin/adiponectin signaling in endometrial cells, suggesting an improvement in insulin action and reproductive failures observed in endometria from women with obesity/PCOS.
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Xiao, Luhua, Xiaoying Lu, Huilin Yang, Cuiqing Lin, Le Li, Chen Ni, Yuan Fang, Suifen Mo, Ruoting Zhan, and Ping Yan. "The Antioxidant and Hypolipidemic Effects of Mesona Chinensis Benth Extracts." Molecules 27, no. 11 (May 26, 2022): 3423. http://dx.doi.org/10.3390/molecules27113423.
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In this study, the antioxidant and hypolipidemic effects of Mesona Chinensis Benth (MCB) extracts were evaluated. Seven fractions (F0, F10, F20, F30, F40, F50 and MTF) were obtained from the MCB ethanol extracts. Compared to the commercial antioxidants (vitamin C), MTF and F30 exhibited higher antioxidant activities in the antiradical activity test and the FRAP assay. The half-inhibition concentration (IC50) for MTF and F30 were 5.323 µg/mL and 5.278 µg/mL, respectively. MTF at 200 µg/mL significantly decreased the accumulation of TG in oleic acid (OA)-induced HepG2 cells and reversed the inhibitory effect of Compound C on AMPK (MTF and F30 significantly increased the glucose utilization of insulin-induced HepG2 cells). In addition, the components of MTF were identified by HPLC-MS, which were caffeic acid, quercetin 3-O-galactoside, isoquercetin, astragalin, rosmarinic acid, aromadendrin-3-O-rutinoside, rosmarinic acid-3-O-glucoside and kaempferol-7-O-glucoside. Through statistical correlations by Simca P software, it was found that the main antioxidant and hypolipidemic components of MCB might be caffeic acid, kaempferol-7-O-glucoside, rosmarinic acid-3-O-glucoside and aromadendrin-3-O-rutinoside, which may play important roles in the AMPK pathway. MTF and F30 in MCB could be potential health products for the treatment of hyperlipidemia.
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Taek Lim, Woo, Ki Jeong Kim, Dong Hee Hong, Cheong Hwan Lim, and Hong Ryang Jung. "Measuring image sharpness using modulation transfer function in magnetic resonance imaging." International Journal of Engineering & Technology 7, no. 2.12 (April 3, 2018): 115. http://dx.doi.org/10.14419/ijet.v7i2.12.11104.
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Background/Objectives: The purpose of this study was to propose a method to maintain the objectivity and validity of measuring image sharpness by changes of ETL using MTF in MRI quantitatively and provide fundamental data for future evaluation and management of magnetic resource imaging quality.Methods/Statistical analysis: We conducted phantom test using ACR MRI phantom. ImageJ and OriginPro programs were used for MTF measurement. For MTF measurement using edge method, after achieving ESF by using ImageJ, LSF was calculated by differentiation in OriginPro. Finally, MTF value was obtained through conversion. Image sharpness was defined based on 50% of MTF value.Findings: Results of sharpness measurement by ETL increase revealed that MTF 50% was decreased when ETL was increased. Sharpness comparison between 1ch head coil and 8ch brain coil at 1.5T showed that it was higher for 1ch head coil, although the difference between the two was not statistically significant. However, sharpness of 1ch head coil at 3.0T MRI was found to be significantly higher than that of 8ch brain coil at 3.0T MRI.Improvements/Applications: This study confirms the theoretical concept that MTF measured by ACR standard phantom can be used as a quantitative evaluation method for spatial resolution in the magnetic resonance medical image quality management. It can be considered a meaningful objective evaluation method.
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Kim, Dong-Ho, Changkyoo Choi, Chulmin Lee, Rusnang Syamsul Adha, Thanh-Tin Nguyen, Sang-Jun Ahn, Hee-Jong Son, and In S. Kim. "An Improved Configuration of Vertical-Flow Mesh Tube Filters for Seawater Pretreatment: Performance, Cleaning, and Energy Consumption." Water 12, no. 10 (October 10, 2020): 2804. http://dx.doi.org/10.3390/w12102804.
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Roughing filters are types of porous media filter used in pretreatment systems where the raw water contains a large amount of suspended particles (SPs) and organic matter. Mesh tube filtration (MTF) media are roughing-filter media composed of low-density polyethylene used for SP removal during wastewater treatment. In this study, we present an improved MTF design—a porous filter bed (PFB), which exhibits superior SP removal performance compared to conventional MTF media. We then compare the applicability of MTF and PFB to both the primary pretreatment process for seawater desalination and the water reuse process. In bench-scale SP removal experiments, PFB shows removal rates of 46.7%, 68.0%, 67.6%, and 68.4% at hydraulic retention times of 15, 20, 30, and 60 min, respectively, which are better than those of MTF. The specific energy consumption (SEC) of batch dissolved air flotation (DAF) was known to range from 0.035 to 0.047 kWh/m3, whereas the SEC calculated for pilot-scale MTF and PFB is 0.027 kWh/m3 and minimum energy for influent supply, respectively. This suggests that PFB can compete with DAF as a primary pretreatment process. MTF predominantly removes SPs by sedimentation, whereas SP removal in PFB typically occurs via deposition of SPs on the mesh tube media.
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Gong, Guangming, Haipo Yuan, Ya Liu, and Luguang Qi. "Investigation of the Effects and Mechanisms of Mai Tong Formula on Lower Limb Macroangiopathy in a Spontaneous Diabetic Rat Model." Journal of Diabetes Research 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/8076796.
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A new Chinese herbal formula called Mai Tong Formulae (MTF) has recently been used to treat lower limb macroangiopathy in type 2 diabetes mellitus (T2DM) patients. In this study, we investigated the effect of MTF on lower limb macroangiopathy in a spontaneous diabetic rat model (GK rats). We found that MTF treatment significantly reduced serum fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), IL6, and VEGF and increased serum insulin in this model. Histological and ultrastructural observations showed that MTF treatment significantly reduced vascular endothelial cell shedding and improved endothelium injuries. We further detect proteome alteration following MTF treatment. 25 differential proteins (DPs) abnormally expressed in GK rats were normalized by MTF treatment. These DPs significantly are enriched in biological processes and pathways that regulate muscle contraction and cGMP-PKG signaling pathway and so on. Additional protein-protein interaction (PPI) network analyses of the DPs showed that Fasn and Prkar2a are involved in the AMPK signaling pathway, and Gnas, Myh11, and Myh6 are involved in vascular smooth muscle contraction; these 5 DPs were validated by Western blotting. These results indicate that MTF treatment effectively treats lower limb macroangiopathy by regulating key proteins involved in AMPK signaling pathway and vascular smooth muscle contraction.
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Lindert, Uschi, Mirjam Cramer, Michael Meuli, Oleg Georgiev, and Walter Schaffner. "Metal-Responsive Transcription Factor 1 (MTF-1) Activity Is Regulated by a Nonconventional Nuclear Localization Signal and a Metal-Responsive Transactivation Domain." Molecular and Cellular Biology 29, no. 23 (September 21, 2009): 6283–93. http://dx.doi.org/10.1128/mcb.00847-09.
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ABSTRACT Metal-responsive transcription factor 1 (MTF-1) mediates both basal and heavy metal-induced transcription of metallothionein genes and also regulates other genes involved in the cell stress response and in metal homeostasis. In resting cells, MTF-1 localizes to both the cytoplasm and the nucleus but quantitatively accumulates in the nucleus upon metal load and under other stress conditions. Here we show that within the DNA-binding domain, a region spanning zinc fingers 1 to 3 (amino acids [aa] 137 to 228 in human MTF-1) harbors a nonconventional nuclear localization signal. This protein segment confers constitutive nuclear localization to a cytoplasmic marker protein. The deletion of the three zinc fingers impairs nuclear localization. The export of MTF-1 to the cytoplasm is controlled by a classical nuclear export signal (NES) embedded in the acidic activation domain. We show that this activation domain confers metal inducibility in distinct cell types when fused to a heterologous DNA-binding domain. Furthermore, the cause of a previously described stronger inducibility of human versus mouse MTF-1 could be narrowed down to a 3-aa difference in the NES; “humanizing” mouse MTF-1 at these three positions enhanced its metal inducibility to the level of human MTF-1.
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Kumchenko, S., A. Tkhostov, and E. Rasskazova. "Salience of self-identification of transsexual people in different stages of medical transition." European Psychiatry 64, S1 (April 2021): S549. http://dx.doi.org/10.1192/j.eurpsy.2021.1463.
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IntroductionTranssexuals are considered to be stable in their identity (White Hughto et al., 2016). Meanwhile, the stages of medical transition affect the mental state of transsexuals differently.ObjectivesThe aim was to reveal relationships between salience of self-identification in transsexual people being on different stages of medical transition.Methods151 transsexual people: 55 pre-operated Female-to-Male (FtM I), 25 FtM on a hormonal therapy (FtM II), 25 FtM after some surgical operations (FtM III); 12 pre-operated Male-to-Female-Transsexual (MtF I), 16 MtF on a hormonal therapy (MtF II), 18 MtF after some surgical operations (MtF III). The participants filled the modificated Kuhn’s test “Who am I?” (Tkhostov et al., 2014). The modification includes a Likert scale for evaluating one’s self-identifications in terms of salience: “How often do You think or remember this answer?” (Stryker, 2007).ResultsThere were differences between identity salience and stages of medical transition (F = 7,177; P < 0,001; η2 = 0,108). Transsexuals before medical transition demonstrated higher levels of identity salience (average score is 7,62 in FtM I and 7,75 in MtF I). Transsexuals on a hormonal therapy demonstrated sharply decreased level of identity salience (6,97 in FtM II and 6,19 in MtF II). Transsexuals after surgical operations reported increased level of salience (7,81 in FtM III and 7,23 in MtF III). There were no statistically significant differences between the groups by gender assigned at birth.ConclusionsData suggest that medical transition could change the salience of self-identification. Hormone therapy is associated with a sharp revision of the salience of self-identifications for transsexuals.
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Li, Yong, Tomoki Kimura, Ryan W. Huyck, John H. Laity, and Glen K. Andrews. "Zinc-Induced Formation of a Coactivator Complex Containing the Zinc-Sensing Transcription Factor MTF-1, p300/CBP, and Sp1." Molecular and Cellular Biology 28, no. 13 (May 5, 2008): 4275–84. http://dx.doi.org/10.1128/mcb.00369-08.
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ABSTRACTHerein, the mechanisms of transactivation of gene expression by mouse metal response element-binding transcription factor 1 (MTF-1) were investigated. Evidence obtained from coimmunoprecipitation assays revealed that exposure of the cells to zinc resulted in the rapid formation of a multiprotein complex containing MTF-1, the histone acetyltransferase p300/CBP, and the transcription factor Sp1. Down-regulation of endogenous p300 expression by small interfering RNA transfection significantly decreased zinc-dependent metallothionein I (MT-I) gene transcription without altering induction of zinc transporter 1 (ZnT1). MTF-1 independently facilitated the recruitment of Sp1 and p300 to the protein complex in response to zinc. Mutagenesis demonstrated that the acidic domain, one of three transactivation domains of MTF-1, is required for recruitment of p300 but not Sp1 as well as for zinc-dependent activation ofMT-Igene transcription. Furthermore, mutation of leucine residues (L→A) within a nuclear exclusion signal in the MTF-1 acidic domain impaired recruitment of p300 and zinc-dependent activation of theMT-Igene. Nuclear magnetic resonance characterization of an isolated protein fragment corresponding to the MTF-1 acidic region demonstrated that this region is largely unstructured in the presence and absence of excess stoichiometric amounts of zinc. This suggests that the mechanism by which MTF-1 recruits p300 to this complex involves extrinsic-zinc-dependent steps. These studies reveal a novel zinc-responsive mechanism requiring an acidic region of MTF-1 that functions as a nuclear exclusion signal as well as participating in formation of a coactivator complex essential for transactivation ofMT-Igene expression.
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JIANG, Huimin, Kai FU, and Glen K. ANDREWS. "Gene- and cell-type-specific effects of signal transduction cascades on metal-regulated gene transcription appear to be independent of changes in the phosphorylation of metal-response-element-binding transcription factor-1." Biochemical Journal 382, no. 1 (August 10, 2004): 33–41. http://dx.doi.org/10.1042/bj20040504.
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Post-translational modification of MTF-1 (metal-response-element-binding transcription factor-1) was suggested to play a role in its metalloregulatory functions. In the present study, pulse labelling and two-dimensional electrophoresis–Western blotting were used to demonstrate that, although MTF-1 is highly modified in vivo, its phosphorylation level does not rapidly change in response to metals, nor does its overall modification pattern. Recombinant MTF-1 was found to serve as an in vitro substrate for casein kinase II, c-Jun N-terminal kinase and protein kinase C, but inhibition of these kinases in vivo did not significantly change the modification pattern of MTF-1. Northern blotting revealed that inhibitors of casein kinase II and c-Jun N-terminal kinase severely attenuate the metal-induced transcription of the native chromatin-packaged metallothionein-I and zinc transporter-1 genes, whereas protein kinase C inhibitors exerted gene- and cell-type-specific effects on the metal regulation and basal expression of these two genes. A chromatin immunoprecipitation assay was used to demonstrate that none of these inhibitors prevent the metal-dependent recruitment of MTF-1 to the MT-I promoter. In brief, results of the present study suggest that protein kinases may not alter the phosphorylation state of MTF-1 during the rapid-response phase to metals, nor do they regulate the metal-dependent formation of a stable MTF-1–chromatin complex. Instead, protein kinases may exert their interdependent effects on metal-induced gene expression by acting on cofactors that interact with MTF-1.
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Cazzola, Mario, Rosangela Invernizzi, Gaetano Bergamaschi, Sonia Levi, Barbara Corsi, Erica Travaglino, Valeria Rolandi, Giorgio Biasiotto, Jim Drysdale, and Paolo Arosio. "Mitochondrial ferritin expression in erythroid cells from patients with sideroblastic anemia." Blood 101, no. 5 (March 1, 2003): 1996–2000. http://dx.doi.org/10.1182/blood-2002-07-2006.
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The sideroblastic anemias are characterized by ring sideroblasts, that is, red cell precursors with mitochondrial iron accumulation. We therefore studied the expression of mitochondrial ferritin (MtF) in these conditions. Erythroid cells from 13 patients with refractory anemia with ring sideroblasts (RARS) and 3 patients with X-linked sideroblastic anemia (XLSA) were analyzed for the distribution of cytoplasmic H ferritin (HF) and MtF using immunocytochemical methods. We also studied 11 healthy controls, 5 patients with refractory anemia without ring sideroblasts (RA), and 7 patients with RA with excess of blasts (RAEB). About one fourth of normal immature red cells, mostly proerythroblasts and basophilic erythroblasts, showed diffuse cytoplasmic positivity for HF, but very few were positive for MtF (0%-10%). Similar patterns were found in anemic patients without ring sideroblasts. In contrast, many erythroblasts from patients with sideroblastic anemia (82%-90% in XLSA and 36%-84% in RARS) were positive for MtF, which regularly appeared as granules ringing the nucleus. Double immunocytochemical staining confirmed the different cellular distribution of HF and MtF. There was a highly significant relationship between the percentage of MtF+ erythroblasts and that of ring sideroblasts (SpearmanR = 0.90; P < .0001). Reverse transcription-polymerase chain reaction studies demonstrated the presence of MtF mRNA in circulating reticulocytes of 2 patients with XLSA but not in controls. These findings suggest that most of the iron deposited in perinuclear mitochondria of ring sideroblasts is present in the form of MtF and that this latter might be a specific marker of sideroblastic anemia.
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Peterson, Kenneth R., Flavia C. Costa, Halyna Fedosyuk, Renee Neades, Johana Bravo de los Rios, Andrea Fonteles, Lesya Zelenchuk, Prarthana Dalal, and Gabriella Maniscalco. "Induction of Fetal Hemoglobin by Transcriptional Co-Activators MTF-1 and TSPYL1." Blood 118, no. 21 (November 18, 2011): 353. http://dx.doi.org/10.1182/blood.v118.21.353.353.
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Abstract Abstract 353 Sickle cell disease (SCD) impacts one of 400 African-Americans born each year. Augmentation of fetal hemoglobin (HbF) levels is widely accepted as the most effective method for treating SCD, but hydroxyurea (HU) is currently the only approved drug that increases HbF. Thus, there is a need for the development of new therapies for this disease, including the identification of transcriptional activators that specifically up-regulate γ-globin (HbF). Developmental regulation of human β-like globin gene switching is controlled by several parameters, including cis- and trans-acting transcriptional determinants. Understanding the mechanisms underlying control of globin gene expression, particularly those involved in activation of γ-globin expression (HbF) is important for developing new treatments for SCD. Metal-responsive transcription factor-1 (MTF-1) is a key regulator of zinc metabolism in higher eukaryotes that controls the metal-inducible expression of metallothioneins and a number of other genes directly involved in the intracellular sequestration and efflux transport of zinc. Previous studies demonstrated that MTF-1 plays an essential role in liver development and that MTF-1-deficient mice display an anemic phenotype, suggesting a role for MTF-1 in hematopoiesis. In our study, when murine MTF-1 was expression was enforced, we observed a 5-fold increase in γ-globin expression in K562 cells. We also demonstrated increased γ-globin expression in adult blood from MTF-1 human β-globin locus yeast artificial chromosome (β-YAC) bi-transgenic (bigenic) mouse lines at the mRNA level by quantitative real-time RT-PCR (qPCR) and at the protein level by FACS analysis. Lastly, γ-globin gene expression was induced 12-fold in bone marrow cells (BMCs) derived from these bigenic mice compared to BMCs derived from β-YAC-only mice, and 3-fold after 6 hours of zinc treatment in β-YAC-only BMCs. Corroborative studies including zinc-deficient and zinc replete diets in β-YAC mice and erythroid-specific MTF-1 loss-of-function in loxP-flanked-MTF-1 LCR-β-globin promoter-Cre β-YAC mice further support a role for MTF-1 in g-globin gene expression. Chromatin immunoprecipitation (ChIP) analysis did not show recruitment of MTF-1 to any γ-globin gene-proximal metal response elements (MREs), the DNA motif that MTF-1 binds to control zinc metabolism genes. However, GATA-2 co-immunoprecipitated with MTF-1 in MTF-1 β-YAC BMCs, but not in β-YAC-only BMCs, suggesting that reactivation of γ-globin expression by MTF-1 might be mediated by a MTF-1-GATA-2 protein complex. ChIP experiments indicated that MTF-1 and GATA-2 co-occupy the same sites in the γ-globin promoter. Two of the stronger co-recruitment regions contain not only GATA sites, but also non-canonical MREs that vary by 1 or 2 bp from the canonical 7 bp MRE core. Interestingly, GATA-2 was induced 2-fold in adult blood of MTF-1 β-YAC mice, and also 3.5-fold in MTF-1 β-YAC BMCs treated with zinc for 6 hours. Our data suggest that activation of γ-globin by MTF-1 is mediated by protein-protein interaction with GATA-2 and that this multi-protein complex is targeted to GATA sites located in the γ-globin gene-promoters via binding of the GATA-2 protein. In a previous study we identified testis-specific protein Y-like 1 (TSPYL1) as a candidate gene involved in activation of γ-globin (de Andrade et al., 2006, Blood Cells, Mol. & Dis. 37:82). TSPYL1 mRNA level was increased 2–5 fold in deletional hereditary persistence of fetal hemoglobin (HPFH-2) subjects and decreased in a carrier of the Sicilian δβ-thalassemia trait. TSPYL1 is a transcription factor that is a member of the nucleosome assembly protein (NAP) family. TSPYL1 is not a DNA-binding protein; thus it exerts its effect through protein-protein interactions. When we enforced expression of human TSPYL1 in K562 cells an 11-fold induction of γ-globin expression was obtained. A reduction of γ-globin expression was observed following TSPYL1 knockdown in K562 cells. qPCR analysis of blood from TSPYL1 β-YAC bigenic mice showed that γ-globin expression was increased 4–12-fold. Taken together, our data strongly support the evidence that MTF-1 and TSPYL1 reactivate γ-globin expression in adult erythropoiesis. These two proteins represent potential new targets in strategies to reactivate γ-globin in hemoglobinopathies where higher levels of HbF would have beneficial effects. Disclosures: No relevant conflicts of interest to declare.
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Dalton, T. P., D. Bittel, and G. K. Andrews. "Reversible activation of mouse metal response element-binding transcription factor 1 DNA binding involves zinc interaction with the zinc finger domain." Molecular and Cellular Biology 17, no. 5 (May 1997): 2781–89. http://dx.doi.org/10.1128/mcb.17.5.2781.
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The DNA-binding activity of the Zn finger protein metal response element-binding transcription factor 1 (MTF-1) was rapidly induced both in vivo in mouse Hepa cells, canine MDCK, and human HeLa cells after incubation in medium containing zinc and in vitro in whole-cell extracts to which zinc was added. Acquisition of DNA-binding capacity in the presence of free zinc was temperature and time dependent and did not occur at 4 degrees C. In contrast, activated MTF-1 binding to the metal response element occurred at 4 degrees C. After Zn activation, mouse MTF-1 binding activity was more sensitive to EDTA and was stabilized by DNA binding relative to the Zn finger transcription factor Sp1. After dilution of nuclear or whole-cell extracts from Zn-treated cells and incubation at 37 degrees C, mouse MTF-1 DNA-binding activity was no longer detected but could be completely reconstituted by the subsequent readdition of zinc. In vitro-synthesized, recombinant mouse MTF-1 displayed a similar, reversible temperature- and Zn-dependent activation of DNA-binding activity. Analysis of deletion mutants of recombinant MTF-1 suggests that the Zn finger domain is important for the Zn-dependent activation of DNA-binding capacity. Thus, mouse MTF-1 functions as a reversibly activated sensor of free zinc pools in the cell.
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Jang, Woonyoung, and Jan Allebach. "Characterization of Printer MTF." Journal of Imaging Science and Technology 50, no. 3 (May 1, 2006): 264–75. http://dx.doi.org/10.2352/j.imagingsci.technol.(2006)50:3(264).
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Shcherback, I., and O. Yadid-Pecht. "CMOS APS MTF modeling." IEEE Transactions on Electron Devices 48, no. 12 (2001): 2710–15. http://dx.doi.org/10.1109/16.974694.
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Fallah, Hamid Reza, and Ayatollah Karimzadeh. "MTF of compound eye." Optics Express 18, no. 12 (May 26, 2010): 12304. http://dx.doi.org/10.1364/oe.18.012304.
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