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Full-Text Articles in Medicine and Health Sciences
Genome-Scale Metabolic Modeling Reveals Sequential Dysregulation Of Glutathione Metabolism In Livers From Patients With Alcoholic Hepatitis, Alexandra Manchel, Radhakrishnan Mahadevan, Ramon Bataller, Jan B. Hoek, Rajanikanth Vadigepalli
Genome-Scale Metabolic Modeling Reveals Sequential Dysregulation Of Glutathione Metabolism In Livers From Patients With Alcoholic Hepatitis, Alexandra Manchel, Radhakrishnan Mahadevan, Ramon Bataller, Jan B. Hoek, Rajanikanth Vadigepalli
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Alcoholic hepatitis (AH) is the most severe form of alcoholic liver disease for which there is no efficacious treatment aiding most patients. AH manifests differently in individuals, with some patients showing debilitating symptoms more so than others. Previous studies showed significant metabolic dysregulation associated with AH. Therefore, we sought to analyze how the activity of metabolic pathways differed in the liver of patients with varying degrees of AH severity. We utilized a genome-scale metabolic modeling approach that allowed for integration of a generic human cellular metabolic model with specific RNA-seq data corresponding to healthy and multiple liver disease states to …
Arsenic Toxicity On Metabolism And Autophagy In Adipose And Muscle Tissues, Seung-Hyun Ro, Jiyoung Bae, Yura Jang, Jacob Myers, Soonkyu Chung, Jiujiu Yu, Sathish Kumar Natarajan, Rodrigo Franco, Hyun-Seob Song
Arsenic Toxicity On Metabolism And Autophagy In Adipose And Muscle Tissues, Seung-Hyun Ro, Jiyoung Bae, Yura Jang, Jacob Myers, Soonkyu Chung, Jiujiu Yu, Sathish Kumar Natarajan, Rodrigo Franco, Hyun-Seob Song
Department of Microbiology and Immunology Faculty Papers
Arsenic, a naturally occurring metalloid derived from the environment, has been studied worldwide for its causative effects in various cancers. However, the effects of arsenic toxicity on the development and progression of metabolic syndrome, including obesity and diabetes, has received less attention. Many studies suggest that metabolic dysfunction and autophagy dysregulation of adipose and muscle tissues are closely related to the development of metabolic disease. In the USA, arsenic contamination has been reported in some ground water, soil and grain samples in major agricultural regions, but the effects on adipose and muscle tissue metabolism and autophagy have not been investigated …
A Cancer Ubiquitome Landscape Identifies Metabolic Reprogramming As Target Of Parkin Tumor Suppression, Ekta Agarwal, Aaron R Goldman, Hsin-Yao Tang, Andrew V Kossenkov, Jagadish C Ghosh, Lucia Languino, Valentina Vaira, David W Speicher, Dario C Altieri
A Cancer Ubiquitome Landscape Identifies Metabolic Reprogramming As Target Of Parkin Tumor Suppression, Ekta Agarwal, Aaron R Goldman, Hsin-Yao Tang, Andrew V Kossenkov, Jagadish C Ghosh, Lucia Languino, Valentina Vaira, David W Speicher, Dario C Altieri
Department of Cancer Biology Faculty Papers
Changes in metabolism that affect mitochondrial and glycolytic networks are hallmarks of cancer, but their impact in disease is still elusive. Using global proteomics and ubiquitome screens, we now show that Parkin, an E3 ubiquitin ligase and key effector of mitophagy altered in Parkinson's disease, shuts off mitochondrial dynamics and inhibits the non-oxidative phase of the pentose phosphate pathway. This blocks tumor cell movements, creates metabolic and oxidative stress, and inhibits primary and metastatic tumor growth. Uniformly down-regulated in cancer patients, Parkin tumor suppression requires its E3 ligase function, is reversed by antioxidants, and is independent of mitophagy. These data …
Myc-Mediated Transcriptional Regulation Of The Mitochondrial Chaperone Trap1 Controls Primary And Metastatic Tumor Growth., Ekta Agarwal, Brian J. Altman, Jae Ho Seo, Jagadish C. Ghosh, Andrew V Kossenkov, Hsin-Yao Tang, Shiv Ram Krishn, Lucia R. Languino, Dmitry I. Gabrilovich, David W. Speicher, Chi V. Dang, Dario C. Altieri
Myc-Mediated Transcriptional Regulation Of The Mitochondrial Chaperone Trap1 Controls Primary And Metastatic Tumor Growth., Ekta Agarwal, Brian J. Altman, Jae Ho Seo, Jagadish C. Ghosh, Andrew V Kossenkov, Hsin-Yao Tang, Shiv Ram Krishn, Lucia R. Languino, Dmitry I. Gabrilovich, David W. Speicher, Chi V. Dang, Dario C. Altieri
Department of Cancer Biology Faculty Papers
The role of mitochondria in cancer continues to be debated, and whether exploitation of mitochondrial functions is a general hallmark of malignancy or a tumor- or context-specific response is still unknown. Using a variety of cancer cell lines and several technical approaches, including siRNA-mediated gene silencing, ChIP assays, global metabolomics and focused metabolite analyses, bioenergetics, and cell viability assays, we show that two oncogenic Myc proteins, c-Myc and N-Myc, transcriptionally control the expression of the mitochondrial chaperone TNFR-associated protein- 1 (TRAP1) in cancer. In turn, this Myc-mediated regulation preserved the folding and function of mitochondrial oxidative phosphorylation (OXPHOS) complex II …
Highly Efficient 5' Capping Of Mitochondrial Rna With Nad+ And Nadh By Yeast And Human Mitochondrial Rna Polymerase, Jeremy G Bird, Urmimala Basu, David Kuster, Aparna Ramachandran, Ewa Grudzien-Nogalska, Atif Towheed, Douglas C. Wallace, Megerditch Kiledjian, Dmitry Temiakov, Smita S. Patel, Richard H. Ebright, Bryce E. Nickels
Highly Efficient 5' Capping Of Mitochondrial Rna With Nad+ And Nadh By Yeast And Human Mitochondrial Rna Polymerase, Jeremy G Bird, Urmimala Basu, David Kuster, Aparna Ramachandran, Ewa Grudzien-Nogalska, Atif Towheed, Douglas C. Wallace, Megerditch Kiledjian, Dmitry Temiakov, Smita S. Patel, Richard H. Ebright, Bryce E. Nickels
Department of Biochemistry and Molecular Biology Faculty Papers
Bacterial and eukaryotic nuclear RNA polymerases (RNAPs) cap RNA with the oxidized and reduced forms of the metabolic effector nicotinamide adenine dinucleotide, NAD+ and NADH, using NAD+ and NADH as non-canonical initiating nucleotides for transcription initiation. Here, we show that mitochondrial RNAPs (mtRNAPs) cap RNA with NAD+ and NADH, and do so more efficiently than nuclear RNAPs. Direct quantitation of NAD+- and NADH-capped RNA demonstrates remarkably high levels of capping in vivo: up to ~60% NAD+ and NADH capping of yeast mitochondrial transcripts, and up to ~15% NAD+ capping of human mitochondrial transcripts. The capping efficiency is determined by promoter …
Bonded Cumomer Analysis Of Human Melanoma Metabolism Monitored By 13c Nmr Spectroscopy Of Perfused Tumor Cells., Alexander A Shestov, Anthony Mancuso, Seung-Cheol Lee, Lili Guo, David S Nelson, Jeffrey C Roman, Pierre-Gilles Henry, Dennis B. Leeper, Ian A Blair, Jerry D Glickson
Bonded Cumomer Analysis Of Human Melanoma Metabolism Monitored By 13c Nmr Spectroscopy Of Perfused Tumor Cells., Alexander A Shestov, Anthony Mancuso, Seung-Cheol Lee, Lili Guo, David S Nelson, Jeffrey C Roman, Pierre-Gilles Henry, Dennis B. Leeper, Ian A Blair, Jerry D Glickson
Department of Radiation Oncology Faculty Papers
A network model for the determination of tumor metabolic fluxes from (13)C NMR kinetic isotopomer data has been developed and validated with perfused human DB-1 melanoma cells carrying the BRAF V600E mutation, which promotes oxidative metabolism. The model generated in the bonded cumomer formalism describes key pathways of tumor intermediary metabolism and yields dynamic curves for positional isotopic enrichment and spin-spin multiplets. Cells attached to microcarrier beads were perfused with 26 mm [1,6-(13)C2]glucose under normoxic conditions at 37 °C and monitored by (13)C NMR spectroscopy. Excellent agreement between model-predicted and experimentally measured values of the rates of oxygen and glucose …
Regulation Of Lipogenesis By Cyclin-Dependent Kinase 8-Mediated Control Of Srebp-1., Xiaoping Zhao, Daorong Feng, Qun Wang, Arian Abdulla, Xiao-Jun Xie, Jie Zhou, Yan Sun, Ellen S Yang, Lu-Ping Liu, Bhavapriya Vaitheesvaran, Lauren Bridges, Irwin J Kurland, Randy Strich, Jian-Quan Ni, Chenguang Wang, Johan Ericsson, Jeffrey E Pessin, Jun-Yuan Ji, Fajun Yang
Regulation Of Lipogenesis By Cyclin-Dependent Kinase 8-Mediated Control Of Srebp-1., Xiaoping Zhao, Daorong Feng, Qun Wang, Arian Abdulla, Xiao-Jun Xie, Jie Zhou, Yan Sun, Ellen S Yang, Lu-Ping Liu, Bhavapriya Vaitheesvaran, Lauren Bridges, Irwin J Kurland, Randy Strich, Jian-Quan Ni, Chenguang Wang, Johan Ericsson, Jeffrey E Pessin, Jun-Yuan Ji, Fajun Yang
Department of Cancer Biology Faculty Papers
Altered lipid metabolism underlies several major human diseases, including obesity and type 2 diabetes. However, lipid metabolism pathophysiology remains poorly understood at the molecular level. Insulin is the primary stimulator of hepatic lipogenesis through activation of the SREBP-1c transcription factor. Here we identified cyclin-dependent kinase 8 (CDK8) and its regulatory partner cyclin C (CycC) as negative regulators of the lipogenic pathway in Drosophila, mammalian hepatocytes, and mouse liver. The inhibitory effect of CDK8 and CycC on de novo lipogenesis was mediated through CDK8 phosphorylation of nuclear SREBP-1c at a conserved threonine residue. Phosphorylation by CDK8 enhanced SREBP-1c ubiquitination and protein …
Molecular Processes That Handle — And Mishandle — Dietary Lipids, Kevin Jon Williams
Molecular Processes That Handle — And Mishandle — Dietary Lipids, Kevin Jon Williams
Department of Medicine Faculty Papers
Overconsumption of lipid-rich diets, in conjunction with physical inactivity, disables and kills staggering numbers of people worldwide. Recent advances in our molecular understanding of cholesterol and triglyceride transport from the small intestine to the rest of the body provide a detailed picture of the fed/fasted and active/sedentary states. Key surprises include the unexpected nature of many pivotal molecular mediators, as well as their dysregulation — but possible reversibility — in obesity, diabetes, inactivity, and related conditions. These mechanistic insights provide new opportunities to correct dyslipoproteinemia, accelerated atherosclerosis, insulin resistance, and other deadly sequelae of overnutrition and underexertion.
Beta3 Integrin Haplotype Influences Gene Regulation And Plasma Von Willebrand Factor Activity, Katie E. Payne, Paul F. Bray, Peter J. Grant, Angela M. Carter
Beta3 Integrin Haplotype Influences Gene Regulation And Plasma Von Willebrand Factor Activity, Katie E. Payne, Paul F. Bray, Peter J. Grant, Angela M. Carter
Department of Medicine Faculty Papers
The Leu33Pro polymorphism of the gene encoding beta(3) integrin (ITGB3) is associated with acute coronary syndromes and influences platelet aggregation. Three common promoter polymorphisms have also been identified. The aims of this study were to (1) investigate the influence of the ITGB3 -400C/A, -425A/C and -468G/A promoter polymorphisms on reporter gene expression and nuclear protein binding and (2) determine genotype and haplotype associations with platelet alpha(IIb)beta(3) receptor density. Promoter haplotypes were introduced into an ITGB3 promoter-pGL3 construct by site directed mutagenesis and luciferase reporter gene expression analysed in HEL and HMEC-1 cells. Binding of nuclear proteins was assessed by electrophoretic …
A Distinct Role For B1b Lymphocytes In T Cell-Independent Immunity, Kishore R. Alugupalli
A Distinct Role For B1b Lymphocytes In T Cell-Independent Immunity, Kishore R. Alugupalli
Department of Microbiology and Immunology Faculty Papers
Pathogenesis of infectious disease is not only determined by the virulence of the microbe but also by the immune status of the host. Vaccination is the most effective means to control infectious diseases. A hallmark of the adaptive immune system is the generation of B cell memory, which provides a long-lasting protective antibody response that is central to the concept of vaccination. Recent studies revealed a distinct function for B1b lymphocytes, a minor subset of mature B cells that closely resembles that of memory B cells in a number of aspects. In contrast to the development of conventional B cell …
Maternal Cocaine Administration In Mice Alters Dna Methylation And Gene Expression In Hippocampal Neurons Of Neonatal And Prepubertal Offspring, Svetlana I. Novikova, Fang He, Jie Bai, Nicholas J. Cutrufello, Michael S. Lidow, Ashiwel S. Undieh
Maternal Cocaine Administration In Mice Alters Dna Methylation And Gene Expression In Hippocampal Neurons Of Neonatal And Prepubertal Offspring, Svetlana I. Novikova, Fang He, Jie Bai, Nicholas J. Cutrufello, Michael S. Lidow, Ashiwel S. Undieh
College of Pharmacy Faculty Papers
Previous studies documented significant behavioral changes in the offspring of cocaine-exposed mothers. We now explore the hypothesis that maternal cocaine exposure could alter the fetal epigenetic machinery sufficiently to cause lasting neurochemical and functional changes in the offspring. Pregnant CD1 mice were administered either saline or 20 mg/kg cocaine twice daily on gestational days 8-19. Male pups from each of ten litters of the cocaine and control groups were analyzed at 3 (P3) or 30 (P30) days postnatum. Global DNA methylation, methylated DNA immunoprecipitation followed by CGI(2) microarray profiling and bisulfite sequencing, as well as quantitative real-time RT-PCR gene expression …
Diverse Antidepressants Increase Cdp-Diacylglycerol Production And Phosphatidylinositide Resynthesis In Depression-Relevant Regions Of The Rat Brain, Kimberly R. Tyeryar, Habiba O.U. Vongtau, Ashiwel S. Undieh
Diverse Antidepressants Increase Cdp-Diacylglycerol Production And Phosphatidylinositide Resynthesis In Depression-Relevant Regions Of The Rat Brain, Kimberly R. Tyeryar, Habiba O.U. Vongtau, Ashiwel S. Undieh
College of Pharmacy Faculty Papers
BACKGROUND: Major depression is a serious mood disorder affecting millions of adults and children worldwide. While the etiopathology of depression remains obscure, antidepressant medications increase synaptic levels of monoamine neurotransmitters in brain regions associated with the disease. Monoamine transmitters activate multiple signaling cascades some of which have been investigated as potential mediators of depression or antidepressant drug action. However, the diacylglycerol arm of phosphoinositide signaling cascades has not been systematically investigated, even though downstream targets of this cascade have been implicated in depression. With the ultimate goal of uncovering the primary postsynaptic actions that may initiate cellular antidepressive signaling, we …
Bladder Inflammatory Transcriptome In Response To Tachykinins: Neurokinin 1 Receptor-Dependent Genes And Transcription Regulatory Elements, Ricardo Saban, Cindy Simpson, Rajanikanth Vadigepalli, Sylvie Memet, Igor Dozmorov, Marcia R. Saban
Bladder Inflammatory Transcriptome In Response To Tachykinins: Neurokinin 1 Receptor-Dependent Genes And Transcription Regulatory Elements, Ricardo Saban, Cindy Simpson, Rajanikanth Vadigepalli, Sylvie Memet, Igor Dozmorov, Marcia R. Saban
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Background Tachykinins (TK), such as substance P, and their neurokinin receptors which are ubiquitously expressed in the human urinary tract, represent an endogenous system regulating bladder inflammatory, immune responses, and visceral hypersensitivity. Increasing evidence correlates alterations in the TK system with urinary tract diseases such as neurogenic bladders, outflow obstruction, idiopathic detrusor instability, and interstitial cystitis. However, despite promising effects in animal models, there seems to be no published clinical study showing that NK-receptor antagonists are an effective treatment of pain in general or urinary tract disorders, such as detrusor overactivity. In order to search for therapeutic targets that could …
Expression Of The Autoimmune Fcgr2b Nzw Allele Fails To Be Upregulated In Germinal Center B Cells And Is Associated With Increased Igg Production, S.M. Ziaur Rahman, H. Niu, D. Perry, Timothy L. Manser, L. Morel
Expression Of The Autoimmune Fcgr2b Nzw Allele Fails To Be Upregulated In Germinal Center B Cells And Is Associated With Increased Igg Production, S.M. Ziaur Rahman, H. Niu, D. Perry, Timothy L. Manser, L. Morel
Department of Microbiology and Immunology Faculty Papers
The inhibitory receptor FcγRIIb regulates B-cell functions. Genetic studies have associated Fcgr2b polymorphisms and lupus susceptibility in both humans and murine models, in which B cells express reduced FcγRIIb levels. Furthermore, FcγRIIb absence results in lupus on the appropriate genetic background, and lentiviral-mediated FcγRIIb overexpression prevents disease in the NZM2410 lupus mouse. The NZM2410/NZW allele Fcgr2b is, however, located in-between Sle1a and Sle1b, two potent susceptibility loci, making it difficult to evaluate Fcr2bNZW independent contribution. By using two congenic strains that each carries only Sle1a (B6.Sle1a(15–353)), or Fcr2bNZW in the absence of Sle1a or Sle1b (B6.Sle1(111–148)), we show that the …
Untangling The Signalling Wires, Boris N. Kholodenko Phd, Dsci
Untangling The Signalling Wires, Boris N. Kholodenko Phd, Dsci
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Mitogen-activated protein kinase (MAPK) cascades process myriads of stimuli, generating receptor-specific cellular outcomes. New work exploits emergent mathematics of network inference to reveal distinct feedback designs of the RAF/MEK/ERK cascade induced by two different growth factors. It shows that response specificity can arise from differential signal-induced wiring of overlapping protein networks.
Inhibition Of Antiassociation Activity Of Translation Initiation Factor 3 By Paromomycin, Go Hirokawa, Hideko Kaji, Akira Kaji
Inhibition Of Antiassociation Activity Of Translation Initiation Factor 3 By Paromomycin, Go Hirokawa, Hideko Kaji, Akira Kaji
Department of Biochemistry and Molecular Biology Faculty Papers
The effect of paromomycin on the interaction of ribosomal subunits was studied. Paromomycin inhibited the antiassociation activity of initiation factor 3 (IF3). Furthermore, ribosomal subunits were associated to form 70S ribosomes by paromomycin even in the presence of 1 mM Mg(2+). Paromomycin did not inhibit the binding of IF3 to the 30S ribosomal subunits. On the other hand, IF3 bound to the 30S subunits was expelled by paromomycin-induced subunit association (70S formation). These results indicate that the stabilization of 70S ribosomes by paromomycin may in part be responsible for its inhibitory effects on translocation and ribosome recycling.
Combined Effects Of Aldehyde Dehydrogenase Variants And Maternal Mitochondrial Genes On Alcohol Consumption, Yedy Israel, Maria E. Quintanilla, Amalia Sapag, Lutske Tampier
Combined Effects Of Aldehyde Dehydrogenase Variants And Maternal Mitochondrial Genes On Alcohol Consumption, Yedy Israel, Maria E. Quintanilla, Amalia Sapag, Lutske Tampier
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
Two lines of rats bred to differ in their voluntary alcohol consumption — the alcohol-abstaining UChA rats and the alcohol-drinking UChB rats — differ in how effectively toxic acetaldehyde is removed during alcohol metabolism. UChB animals carry efficient variants of the aldehyde dehydrogenase 2 (ALDH2) genes and have active mitochondria, resulting in fast removal of acetaldehyde. UChA animals, in contrast, carry less efficient ALDH2 variants and less active mitochondria, which result in transient elevations of acetaldehyde levels after alcohol ingestion. Cross-breeding studies have demonstrated that the presence of active mitochondria inherited from UChB females can fully abolish the reduction of …
Mixed Germ Cell Sex Cord-Stromal Tumors Of The Testis And Ovary. Morphological, Immunohistochemical, And Molecular Genetic Study Of Seven Cases, Michal Michal, Tomas Vanacek, Radek Sima, Petr Mukensnabl, Ondrej Hes, Dmitry V. Kazakov, Jozef Matoska, Anna Zuntova, Vladimir Dvorak, Alexander Talerman
Mixed Germ Cell Sex Cord-Stromal Tumors Of The Testis And Ovary. Morphological, Immunohistochemical, And Molecular Genetic Study Of Seven Cases, Michal Michal, Tomas Vanacek, Radek Sima, Petr Mukensnabl, Ondrej Hes, Dmitry V. Kazakov, Jozef Matoska, Anna Zuntova, Vladimir Dvorak, Alexander Talerman
Department of Pathology, Anatomy, and Cell Biology Faculty Papers
We present the morphological, immunohistochemical, and molecular genetic features of three cases of testicular and four cases of ovarian mixed germ cell sex cord-stromal tumors (MGSCT). The germ cells in the testicular MGSCTs morphologically differed from those in classical seminomas by lacking the typical "square off" quality of the nuclei. In contrast to the nuclei in classical seminomas, their size in testicular MGSCTs was smaller and nucleoli were inconspicuous and the cytoplasm was Periodic Acid-Schiff(PAS) negative. Quite on the contrary, the variability in the size of the nuclei of the germ cells in the testicular MGSCTs was more similar to …
The Nad(P)H Oxidase Homolog Nox4 Modulates Insulin-Stimulated Generation Of H202 And Plays An Integral Role In Insulin Signal Transduction, Kalyankar Mahadev, Hiroyuki Motoshima, Xiangdong Wu, Jean Marie Ruddy, Rebecca S. Arnold, Guangjie Cheng, J. David Lambeth, Barry J. Goldstein
The Nad(P)H Oxidase Homolog Nox4 Modulates Insulin-Stimulated Generation Of H202 And Plays An Integral Role In Insulin Signal Transduction, Kalyankar Mahadev, Hiroyuki Motoshima, Xiangdong Wu, Jean Marie Ruddy, Rebecca S. Arnold, Guangjie Cheng, J. David Lambeth, Barry J. Goldstein
Department of Medicine Faculty Papers
Insulin stimulation of target cells elicits a burst of H2O2 that enhances tyrosine phosphorylation of the insulin receptor and its cellular substrate proteins as well as distal signaling events in the insulin action cascade. The molecular mechanism coupling the insulin receptor with the cellular oxidant-generating apparatus has not been elucidated. Using reverse transcription-PCR and Northern blot analyses, we found that Nox4, a homolog of gp91phox, the phagocytic NAD(P)H oxidase catalytic subunit, is prominently expressed in insulin-sensitive adipose cells. Adenovirus-mediated expression of Nox4 deletion constructs lacking NAD(P)H or FAD/NAD(P)H cofactor binding domains acted in a dominant-negative …
Anti-Human Immunodeficiency Virus (Hiv) Activities Of Halogenated Gomisin J Derivatives, New Nonnucleoside Inhibitors Of Hiv Type 1 Reverse Transcriptase, Toshiaki Fujihashi, Hiroto Hara, Toshiya Sakata, Kazuya Mori, Hirotaka Higuchi, Akio Tanaka, Hideko Kaji, Akira Kaji
Anti-Human Immunodeficiency Virus (Hiv) Activities Of Halogenated Gomisin J Derivatives, New Nonnucleoside Inhibitors Of Hiv Type 1 Reverse Transcriptase, Toshiaki Fujihashi, Hiroto Hara, Toshiya Sakata, Kazuya Mori, Hirotaka Higuchi, Akio Tanaka, Hideko Kaji, Akira Kaji
Department of Biochemistry and Molecular Biology Faculty Papers
Halogenated gomisin J (a derivative of lignan compound), represented by the bromine derivative 1506 [(6R, 7S, S-biar)-4,9-dibromo-3,10-dihydroxy-1,2,11,12-tetramethoxy-6, 7-dimethyl-5,6,7,8- tetrahydrodibenzo[a,c]cyclo-octene], was found to be a potent inhibitor of the cytopathic effects of human immunodeficiency virus type 1 (HIV-1) on MT-4 human T cells (50% effective dose, 0.1 to 0.5 microM). Gomisin J derivatives were active in preventing p24 production from acutely HIV-1-infected H9 cells. The selective indices (toxic dose/effective dose) of these compounds were as high as > 300 in some systems. 1506 was active against 3'-azido-3'-deoxythymidine-resistant HIV-1 and acted synergistically with AZT and 2',3'-ddC. 1506 inhibited HIV-1 reverse transcriptase (RT) in …
Increased Abundance Of The Receptor-Type Protein-Tyrosine Phosphatase Lar Accounts For The Elevated Insulin Receptor Dephosphorylating Activity In Adipose Tissue Of Obese Human Subjects, Falyaz Ahmad, Robert V. Considine, Barry J. Goldstein
Increased Abundance Of The Receptor-Type Protein-Tyrosine Phosphatase Lar Accounts For The Elevated Insulin Receptor Dephosphorylating Activity In Adipose Tissue Of Obese Human Subjects, Falyaz Ahmad, Robert V. Considine, Barry J. Goldstein
Department of Medicine Faculty Papers
Protein-tyrosine phosphatases (PTPases) have an essential role in the regulation of the steady-state phosphorylation of the insulin receptor and other proteins in the insulin signalling pathway. To examine whether increased PTPase activity is associated with adipose tissue insulin resistance in human obesity we measured PTPase enzyme activity towards the insulin receptor in homogenates of subcutaneous adipose tissue from a series of six lean and six nondiabetic, obese (body mass index > 30) subjects. The obese subjects had a mean 1.74-fold increase in PTPase activity (P < 0.0001) with a striking positive correlation by linear regression analysis between PTPase activity and body mass index among all of the samples (R = 0.918; P < 0.0001). The abundance of three candidate insulin receptor PTPases in adipose tissue was also estimated by immunoblot analysis. The most prominent increase was a 2.03-fold rise in the transmembrane PTPase LAR (P < 0.001). Of the three PTPase examined, only immunodepletion of LAR protein from the homogenates with neutralizing antibodies resulted in normalization of the PTPase activity towards the insulin receptor, demonstrating that the increase in LAR was responsible for the enhanced PTPase activity in the adipose tissue from obese subjects. These studies suggest that increased PTPase activity towards the insulin receptor is a pathogenetic factor in the insulin resistance of adipose tissue in human obesity and provide evidence for a potential role of the LAR PTPase in the regulation of insulin signalling in disease states.
Identification Of Persistent Defects In Insulin Receptor Structure And Function In Capillary Endothelial Cells From Diabetic Rats, Ching Fai Kwok, Barry J. Goldstein, Dirk Muller-Wieland, Tian-Shing Lee, C. Ronald Kahn, George L. King
Identification Of Persistent Defects In Insulin Receptor Structure And Function In Capillary Endothelial Cells From Diabetic Rats, Ching Fai Kwok, Barry J. Goldstein, Dirk Muller-Wieland, Tian-Shing Lee, C. Ronald Kahn, George L. King
Department of Medicine Faculty Papers
Insulin actions and receptors were studied in capillary endothelial cells cultured from diabetic BB rats and their nondiabetic colony mates. The endothelial cells from diabetic rats of 2 mo duration had persistent biological and biochemical defects in culture. Compared with normal rats, endothelial cells from diabetic rats grew 44% more slowly. Binding studies of insulin and insulin-like growth factor I (IGF-I) showed that cells from diabetic rats had 50% decrease of insulin receptor binding (nondiabetic: 4.6 +/- 0.7; diabetic: 2.6 +/- 0.4% per milligram protein, P < 0.01), which was caused by a 50% decrease in the number of binding sites per milligram protein, whereas IGF-I binding was not changed. Insulin stimulation of 2-deoxy-glucose uptake and alpha-aminoisobutyric acid uptake were also severely impaired with a 80-90% decrease in maximal stimulation, in parallel with a 62% decrease in insulin-stimulated autophosphorylation (P < 0.05). 125I-insulin cross-linking revealed an 140-kD alpha subunit of the insulin receptor similar to …
Insulin Degradation By Adipose Tissue. Studies At Several Levels Of Cellular Organization, Barry J. Goldstein, James N. Livingston
Insulin Degradation By Adipose Tissue. Studies At Several Levels Of Cellular Organization, Barry J. Goldstein, James N. Livingston
Department of Medicine Faculty Papers
A systematic study of the degradation of physiological concentrations of 125I-labelled insulin was performed in intact fat-pads, isolated adipocytes and subcellular fractions of isolated adipocytes. The findings indicate that insulin is rapidly degraded to low-molecular-weight peptides and/or amino acids by the intact tissue and isolated cells. Of the total insulin-degradation products present after incubation with an intact fat-pad, 94% is recovered in the medium, indicating that these products are not retained by the cells or tissue. The plasma membranes do not degrade insulin significantly in the absence of reduced glutathione, and over 99% of the cellular degradative capacity is …