Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 64

Full-Text Articles in Life Sciences

The Effects Of Interleukin-10 On Skeletal Muscle Insulin Resistance And Myogenesis, Sezin Dagdeviren Dec 2016

The Effects Of Interleukin-10 On Skeletal Muscle Insulin Resistance And Myogenesis, Sezin Dagdeviren

GSBS Dissertations and Theses

Skeletal muscle insulin resistance is a major characteristic of obesity and type 2 diabetes. Although obesity-mediated inflammation is causally associated with insulin resistance, the underlying mechanism is unclear. Our lab and others have shown that a chronic low-grade inflammation takes place in skeletal muscles during diet-induced obesity, as evidenced by increased macrophage markers and pro-inflammatory cytokine levels. Interleukin (IL)-10 is a Th2-type cytokine that inhibits the synthesis and activity of pro-inflammatory cytokines and counteracts the Toll-like receptor-mediated inflammation. Our lab has previously demonstrated the preventive role of IL-10 against insulin resistance. Here, I have analyzed the effects ...


Phosphorylation Of The Mdm2 Oncoprotein By The C-Abl Tyrosine Kinase Regulates P53 Tumor Suppression And The Radiosensitivity Of Mice, Michael I. Carr, Justine E. Roderick, Hong Zhang, Bruce A. Woda, Michelle A. Kelliher, Stephen N. Jones Dec 2016

Phosphorylation Of The Mdm2 Oncoprotein By The C-Abl Tyrosine Kinase Regulates P53 Tumor Suppression And The Radiosensitivity Of Mice, Michael I. Carr, Justine E. Roderick, Hong Zhang, Bruce A. Woda, Michelle A. Kelliher, Stephen N. Jones

UMass Metabolic Network Publications

The p53 tumor suppressor acts as a guardian of the genome by preventing the propagation of DNA damage-induced breaks and mutations to subsequent generations of cells. We have previously shown that phosphorylation of the Mdm2 oncoprotein at Ser394 by the ATM kinase is required for robust p53 stabilization and activation in cells treated with ionizing radiation, and that loss of Mdm2 Ser394 phosphorylation leads to spontaneous tumorigenesis and radioresistance in Mdm2S394A mice. Previous in vitro data indicate that the c-Abl kinase phosphorylates Mdm2 at the neighboring residue (Tyr393) in response to DNA damage to regulate p53-dependent apoptosis. In this present ...


Wzb117 (2-Fluoro-6-(M-Hydroxybenzoyloxy) Phenyl M-Hydroxybenzoate) Inhibits Glut1-Mediated Sugar Transport By Binding Reversibly At The Exofacial Sugar Binding Site, Ogooluwa A. Ojelabi, Kenneth P. Lloyd, Andrew Simon, Julie K. De Zutter, Anthony Carruthers Dec 2016

Wzb117 (2-Fluoro-6-(M-Hydroxybenzoyloxy) Phenyl M-Hydroxybenzoate) Inhibits Glut1-Mediated Sugar Transport By Binding Reversibly At The Exofacial Sugar Binding Site, Ogooluwa A. Ojelabi, Kenneth P. Lloyd, Andrew Simon, Julie K. De Zutter, Anthony Carruthers

UMass Metabolic Network Publications

WZB117 (2-fluoro-6-(m-hydroxybenzoyloxy) phenyl m-hydroxybenzoate) inhibits passive sugar transport in human erythrocytes and cancer cell lines and, by limiting glycolysis, inhibits tumor growth in mice. This study explores how WZB117 inhibits the erythrocyte sugar transporter glucose transport protein 1 (GLUT1) and examines the transporter isoform specificity of inhibition. WZB117 reversibly and competitively inhibits erythrocyte 3-O-methylglucose (3MG) uptake with Ki(app) = 6 mum but is a noncompetitive inhibitor of sugar exit. Cytochalasin B (CB) is a reversible, noncompetitive inhibitor of 3MG uptake with Ki(app) = 0.3 mum but is a competitive inhibitor of sugar exit indicating that WZB117 and CB ...


Pgc-1alpha Dictates Endothelial Function Through Regulation Of Enos Expression, Siobhan M. Craige, Swenja Kroller-Schon, Chunying Li, Shashi Kant, Shenghe Cai, Kai Chen, Mayur M. Contractor, Yongmei Pei, Eberhard Schulz, John F. Keaney Jr. Dec 2016

Pgc-1alpha Dictates Endothelial Function Through Regulation Of Enos Expression, Siobhan M. Craige, Swenja Kroller-Schon, Chunying Li, Shashi Kant, Shenghe Cai, Kai Chen, Mayur M. Contractor, Yongmei Pei, Eberhard Schulz, John F. Keaney Jr.

UMass Metabolic Network Publications

Endothelial dysfunction is a characteristic of many vascular related diseases such as hypertension. Peroxisome proliferator activated receptor gamma, coactivator 1alpha (PGC-1alpha) is a unique stress sensor that largely acts to promote adaptive responses. Therefore, we sought to define the role of endothelial PGC-1alpha in vascular function using mice with endothelial specific loss of function (PGC-1alpha EC KO) and endothelial specific gain of function (PGC-1alpha EC TG). Here we report that endothelial PGC-1alpha is suppressed in angiotensin-II (ATII)-induced hypertension. Deletion of endothelial PGC-1alpha sensitized mice to endothelial dysfunction and hypertension in response to ATII, whereas PGC-1alpha EC TG mice were ...


Cancer Metabolism: Fueling More Than Just Growth, Namgyu Lee, Dohoon Kim Dec 2016

Cancer Metabolism: Fueling More Than Just Growth, Namgyu Lee, Dohoon Kim

UMass Metabolic Network Publications

The early landmark discoveries in cancer metabolism research have uncovered metabolic processes that support rapid proliferation, such as aerobic glycolysis (Warburg effect), glutaminolysis, and increased nucleotide biosynthesis. However, there are limitations to the effectiveness of specifically targeting the metabolic processes which support rapid proliferation. First, as other normal proliferative tissues also share similar metabolic features, they may also be affected by such treatments. Secondly, targeting proliferative metabolism may only target the highly proliferating "bulk tumor" cells and not the slower-growing, clinically relevant cancer stem cell subpopulations which may be required for an effective cure. An emerging body of research indicates ...


Adipose-Derived Human Stem/Stromal Cells: Comparative Organ Specific Mitochondrial Bioenergy Profiles, Alice S. Ferng, Katherine M. Marsh, Jamie M. Fleming, Renee F. Conway, David Schipper, Naing Bajaj, Alana M. Connell, Tia Pilikian, Kitsie Johnson, Ray Runyan, Stephen M. Black, John A. Szivek, Zain Khalpey Dec 2016

Adipose-Derived Human Stem/Stromal Cells: Comparative Organ Specific Mitochondrial Bioenergy Profiles, Alice S. Ferng, Katherine M. Marsh, Jamie M. Fleming, Renee F. Conway, David Schipper, Naing Bajaj, Alana M. Connell, Tia Pilikian, Kitsie Johnson, Ray Runyan, Stephen M. Black, John A. Szivek, Zain Khalpey

Open Access Articles

BACKGROUND: Adipose-derived stem/stromal cells (ASCs) isolated from the stromal vascular fraction are a source of mesenchymal stem cells that have been shown to be beneficial in many regenerative medicine applications. ASCs are an attractive source of stem cells in particular, due to their lack of immunogenicity. This study examines differences between mitochondrial bioenergetic profiles of ASCs isolated from adipose tissue of five peri-organ regions: pericardial, thymic, knee, shoulder, and abdomen.

RESULTS: Flow cytometry showed that the majority of each ASC population isolated from the adipose tissue of 12 donors, with an n = 3 for each tissue type, were positive ...


Identification Of Essential Metabolic And Genetic Adaptations To The Quiescent State In Mycobacterium Tuberculosis: A Dissertation, Emily S. C. Rittershaus Dec 2016

Identification Of Essential Metabolic And Genetic Adaptations To The Quiescent State In Mycobacterium Tuberculosis: A Dissertation, Emily S. C. Rittershaus

GSBS Dissertations and Theses

Mycobacterium tuberculosis stably adapts to respiratory limited environments by entering into a nongrowing but metabolically active state termed quiescence. This state is inherently tolerant to antibiotics due to a reduction in growth and activity of associated biosynthetic pathways. Understanding the physiology of the quiescent state, therefore, may be useful in developing new strategies to improve drug efficiency. Here, we used an established in vitro model of respiratory stress, hypoxia, to induce quiescence. We utilized metabolomic and genetic approaches to identify essential and active pathways associated with nongrowth. Our metabolomic profile of hypoxic M. tuberculosis revealed an increase in several free ...


Intraflagellar Transport Protein Ift20 Is Essential For Male Fertility And Spermiogenesis In Mice, Zhengang Zhang, Wei Li, Yong Zhang, Ling Zhang, Maria E. Teves, Hong Liu, Jerome F. Strauss 3rd, Gregory J. Pazour, James A. Foster, Rex A. Hess, Zhibing Zhang Nov 2016

Intraflagellar Transport Protein Ift20 Is Essential For Male Fertility And Spermiogenesis In Mice, Zhengang Zhang, Wei Li, Yong Zhang, Ling Zhang, Maria E. Teves, Hong Liu, Jerome F. Strauss 3rd, Gregory J. Pazour, James A. Foster, Rex A. Hess, Zhibing Zhang

University of Massachusetts Medical School Faculty Publications

Intraflagellar transport (IFT) is a conserved mechanism thought to be essential for the assembly and maintenance of cilia and flagella. However, little is known about its role in mammalian sperm flagella formation. To fill this gap, we disrupted the Ift20 gene in male germ cells. Homozygous mutant mice were infertile with significantly reduced sperm counts and motility. In addition, abnormally shaped elongating spermatid heads and bulbous round spermatids were found in the lumen of the seminiferous tubules. Electron microscopy revealed increased cytoplasmic vesicles, fiber-like structures, abnormal accumulation of mitochondria and a decrease in mature lysosomes. The few developed sperm had ...


Altered Interleukin-10 Signaling In Skeletal Muscle Regulates Obesity-Mediated Inflammation And Insulin Resistance, Sezin Dagdeviren, Dae Young Jung, Eunjung Lee, Randall H. Friedline, Hye Lim Noh, Jong Hun. Kim, Payal R. Patel, Nicholas Tsitsilianos, Andrew V. Tsitsilianos, Duy A. Tran, George H. Tsougranis, Caitlyn C. Kearns, Cecilia P. Uong, Jung Yeon. Kwon, Werner Muller, Ki Won. Lee, Jason K. Kim Nov 2016

Altered Interleukin-10 Signaling In Skeletal Muscle Regulates Obesity-Mediated Inflammation And Insulin Resistance, Sezin Dagdeviren, Dae Young Jung, Eunjung Lee, Randall H. Friedline, Hye Lim Noh, Jong Hun. Kim, Payal R. Patel, Nicholas Tsitsilianos, Andrew V. Tsitsilianos, Duy A. Tran, George H. Tsougranis, Caitlyn C. Kearns, Cecilia P. Uong, Jung Yeon. Kwon, Werner Muller, Ki Won. Lee, Jason K. Kim

University of Massachusetts Medical School Faculty Publications

Skeletal muscle insulin resistance is a major characteristic of obesity and type 2 diabetes. Although obesity-mediated inflammation is causally associated with insulin resistance, the underlying mechanism is unclear. Here, we examined the effects of chronic obesity in mice with muscle-specific overexpression of interleukin-10 (MIL10). After 16 weeks of a high-fat diet (HFD), MIL10 mice became markedly obese but showed improved insulin action compared to that of wild-type mice, which was largely due to increased glucose metabolism and reduced inflammation in skeletal muscle. Since leptin regulates inflammation, the beneficial effects of interleukin-10 (IL-10) were further examined in leptin-deficient ob/ob mice ...


Targeting Drug Resistance In Chronic Myeloid Leukemia: A Dissertation, Leyuan Ma Nov 2016

Targeting Drug Resistance In Chronic Myeloid Leukemia: A Dissertation, Leyuan Ma

GSBS Dissertations and Theses

Inhibiting BCR-ABL kinase activity with tyrosine kinase inhibitors (TKIs) has been the frontline therapy for CML. Resistance to TKIs frequently occurs, but the mechanisms remain elusive.

First, to uncover survival pathways involved in TKI resistance in CML, I conducted a genome-wide RNAi screen in human CML cells to identify genes governing cellular sensitivity to the first generation TKI called IM (Gleevec). I identified genes converging on and activating the MEK/ERK pathway through transcriptional up-regulation of PRKCH. Combining IM with a MEK inhibitor synergistically kills TKI-resistant CML cells and CML stem cells.

Next, I performed single cell RNA-seq to compare ...


Transient Runx1 Expression During Early Mesendodermal Differentiation Of Hescs Promotes Epithelial To Mesenchymal Transition Through Tgfb2 Signaling, Jennifer J. Vanoudenhove, Ricardo F. Medina, Prachi N. Ghule University Of Vermont College Of Medicine, Jane B. Lian, Janet L. Stein, Sayyed K. Zaidi, Gary S. Stein Nov 2016

Transient Runx1 Expression During Early Mesendodermal Differentiation Of Hescs Promotes Epithelial To Mesenchymal Transition Through Tgfb2 Signaling, Jennifer J. Vanoudenhove, Ricardo F. Medina, Prachi N. Ghule University Of Vermont College Of Medicine, Jane B. Lian, Janet L. Stein, Sayyed K. Zaidi, Gary S. Stein

Open Access Articles

The transition of human embryonic stem cells (hESCs) from pluripotency to lineage commitment is not fully understood, and a role for phenotypic transcription factors in the initial stages of hESC differentiation remains to be explored. From a screen of candidate factors, we found that RUNX1 is selectively and transiently upregulated early in hESC differentiation to mesendodermal lineages. Transcriptome profiling and functional analyses upon RUNX1 depletion established a role for RUNX1 in promoting cell motility. In parallel, we discovered a loss of repression for several epithelial genes, indicating that loss of RUNX1 impaired an epithelial to mesenchymal transition during differentiation. Cell ...


Chrebp Regulates Fructose-Induced Glucose Production Independently Of Insulin Signaling, Mi-Sung Kim, Sarah A. Krawczyk, Ludivine Doridot, Alan J. Fowler, Jennifer X. Wang, Sunia A. Trauger, Hye Lim Noh, Hee Joon Kang, John K. Meissen, Matthew Blatnik, Jason K. Kim, Michelle Lai, Mark A. Herman Nov 2016

Chrebp Regulates Fructose-Induced Glucose Production Independently Of Insulin Signaling, Mi-Sung Kim, Sarah A. Krawczyk, Ludivine Doridot, Alan J. Fowler, Jennifer X. Wang, Sunia A. Trauger, Hye Lim Noh, Hee Joon Kang, John K. Meissen, Matthew Blatnik, Jason K. Kim, Michelle Lai, Mark A. Herman

University of Massachusetts Medical School Faculty Publications

Obese, insulin-resistant states are characterized by a paradoxical pathogenic condition in which the liver appears to be selectively insulin resistant. Specifically, insulin fails to suppress glucose production, yet successfully stimulates de novo lipogenesis. The mechanisms underlying this dysregulation remain controversial. Here, we hypothesized that carbohydrate-responsive element-binding protein (ChREBP), a transcriptional activator of glycolytic and lipogenic genes, plays a central role in this paradox. Administration of fructose increased hepatic hexose-phosphate levels, activated ChREBP, and caused glucose intolerance, hyperinsulinemia, hypertriglyceridemia, and hepatic steatosis in mice. Activation of ChREBP was required for the increased expression of glycolytic and lipogenic genes as well as ...


Structural And Genetic Analyses Of The Mycobacterium Tuberculosis Protein Kinase B Sensor Domain Identify A Potential Ligand-Binding Site, Daniil M. Prigozhin, Kadamba Papavinasasundaram, Christina E. Baer, Kenan C. Murphy, Alisa Moskaleva, Tony Y. Chen, Tom Alber, Christopher M. Sassetti Oct 2016

Structural And Genetic Analyses Of The Mycobacterium Tuberculosis Protein Kinase B Sensor Domain Identify A Potential Ligand-Binding Site, Daniil M. Prigozhin, Kadamba Papavinasasundaram, Christina E. Baer, Kenan C. Murphy, Alisa Moskaleva, Tony Y. Chen, Tom Alber, Christopher M. Sassetti

UMass Metabolic Network Publications

Monitoring the environment with serine/threonine protein kinases is critical for growth and survival of Mycobacterium tuberculosis, a devastating human pathogen. Protein kinase B (PknB) is a transmembrane serine/threonine protein kinase that acts as an essential regulator of mycobacterial growth and division. The PknB extracellular domain (ECD) consists of four repeats homologous to penicillin-binding protein and serine/threonine kinase associated (PASTA) domains, and binds fragments of peptidoglycan. These properties suggest that PknB activity is modulated by ECD binding to peptidoglycan substructures, however, the molecular mechanisms underpinning PknB regulation remain unclear. In this study, we report structural and genetic characterization ...


Macrophages Are Regulators Of Whole Body Metabolism: A Dissertation, Joseph C. Yawe Oct 2016

Macrophages Are Regulators Of Whole Body Metabolism: A Dissertation, Joseph C. Yawe

GSBS Dissertations and Theses

Obesity is the top risk factor for the development of type 2 diabetes mellitus in humans. Obese adipose tissue, particularly visceral depots, exhibits an increase in macrophage accumulation and is described as being in a state of chronic low-grade inflammation. It is characterized by the increased expression and secretion of inflammatory cytokines produced by both macrophages and adipocytes, and is associated with the development of insulin resistance. Based on these observations, we investigated the potential role of macrophage infiltration on whole body metabolism, using genetic and diet-induced mouse models of obesity.

Using flow cytometry and immunofluorescence imaging we found that ...


A Gene-Centered C. Elegans Protein-Dna Interaction Network Provides A Framework For Functional Predictions, Juan Fuxman Bass, Carles Pons, Lucie Kozlowski, John S. Reece-Hoyes, Shaleen Shrestha, Amy D. Holdorf, Akihiro Mori, Chad L. Myers, Albertha J. M. Walhout Oct 2016

A Gene-Centered C. Elegans Protein-Dna Interaction Network Provides A Framework For Functional Predictions, Juan Fuxman Bass, Carles Pons, Lucie Kozlowski, John S. Reece-Hoyes, Shaleen Shrestha, Amy D. Holdorf, Akihiro Mori, Chad L. Myers, Albertha J. M. Walhout

Open Access Articles

Transcription factors (TFs) play a central role in controlling spatiotemporal gene expression and the response to environmental cues. A comprehensive understanding of gene regulation requires integrating physical protein-DNA interactions (PDIs) with TF regulatory activity, expression patterns, and phenotypic data. Although great progress has been made in mapping PDIs using chromatin immunoprecipitation, these studies have only characterized ~10% of TFs in any metazoan species. The nematode C. elegans has been widely used to study gene regulation due to its compact genome with short regulatory sequences. Here, we delineated the largest gene-centered metazoan PDI network to date by examining interactions between 90 ...


Mtorc2 Promotes Lipid Storage And Suppresses Thermogenesis In Brown Adipose Tissue In Part Through Akt-Independent Regulation Of Foxo1: A Dissertation, Chien-Min Hung Oct 2016

Mtorc2 Promotes Lipid Storage And Suppresses Thermogenesis In Brown Adipose Tissue In Part Through Akt-Independent Regulation Of Foxo1: A Dissertation, Chien-Min Hung

GSBS Dissertations and Theses

Recent studies suggest adipose tissue plays a critical role in regulating whole body energy homeostasis in both animals and humans. In particular, activating brown adipose tissue (BAT) activity is now appreciated as a potential therapeutic strategy against obesity and metabolic disease. However, the signaling circuits that coordinate nutrient uptake and BAT function are poorly understood. Here, I investigated the role of the nutrient-sensing mTOR signaling pathway in BAT by conditionally deleting Rictor, which encodes an essential component of mTOR Complex 2 (mTORC2) either in brown adipocyte precursors or mature brown adipocytes. In general, inhibiting BAT mTORC2 reduces glucose uptake and ...


Cxcr4 Identifies Transitional Bone Marrow Premonocytes That Replenish The Mature Monocyte Pool For Peripheral Responses, Shu Zhen Chong, John E. Harris, Lai Guan Ng Oct 2016

Cxcr4 Identifies Transitional Bone Marrow Premonocytes That Replenish The Mature Monocyte Pool For Peripheral Responses, Shu Zhen Chong, John E. Harris, Lai Guan Ng

UMass Metabolic Network Publications

It is well established that Ly6Chi monocytes develop from common monocyte progenitors (cMoPs) and reside in the bone marrow (BM) until they are mobilized into the circulation. In our study, we found that BM Ly6Chi monocytes are not a homogenous population, as current data would suggest. Using computational analysis approaches to interpret multidimensional datasets, we demonstrate that BM Ly6Chi monocytes consist of two distinct subpopulations (CXCR4hi and CXCR4lo subpopulations) in both mice and humans. Transcriptome studies and in vivo assays revealed functional differences between the two subpopulations. Notably, the CXCR4hi subset proliferates and is immobilized in the BM for the ...


Cxcr4 Identifies Transitional Bone Marrow Premonocytes That Replenish The Mature Monocyte Pool For Peripheral Responses, Shu Zhen Chong, Maximilien Evrard, John E. Harris, Lai Guan Ng Oct 2016

Cxcr4 Identifies Transitional Bone Marrow Premonocytes That Replenish The Mature Monocyte Pool For Peripheral Responses, Shu Zhen Chong, Maximilien Evrard, John E. Harris, Lai Guan Ng

UMass Metabolic Network Publications

It is well established that Ly6Chi monocytes develop from common monocyte progenitors (cMoPs) and reside in the bone marrow (BM) until they are mobilized into the circulation. In our study, we found that BM Ly6Chi monocytes are not a homogenous population, as current data would suggest. Using computational analysis approaches to interpret multidimensional datasets, we demonstrate that BM Ly6Chi monocytes consist of two distinct subpopulations (CXCR4hi and CXCR4lo subpopulations) in both mice and humans. Transcriptome studies and in vivo assays revealed functional differences between the two subpopulations. Notably, the CXCR4hi subset proliferates and is immobilized in the BM for the ...


The Rna-Binding Protein Atx-2 Regulates Cytokinesis Through Par-5 And Zen-4, Megan M. Gnazzo, Eva-Maria E. Uhlemann, Alex R. Villarreal, Masaki Shirayama, Eddie G. Dominguez, Ahna R. Skop Oct 2016

The Rna-Binding Protein Atx-2 Regulates Cytokinesis Through Par-5 And Zen-4, Megan M. Gnazzo, Eva-Maria E. Uhlemann, Alex R. Villarreal, Masaki Shirayama, Eddie G. Dominguez, Ahna R. Skop

Open Access Articles

The spindle midzone harbors both microtubules and proteins necessary for furrow formation and the completion of cytokinesis. However, the mechanisms that mediate the temporal and spatial recruitment of cell division factors to the spindle midzone and midbody remain unclear. Here we describe a mechanism governed by the conserved RNA-binding protein ATX-2/Ataxin-2, which targets and maintains ZEN-4 at the spindle midzone. ATX-2 does this by regulating the amount of PAR-5 at mitotic structures, particularly the spindle, centrosomes, and midbody. Preventing ATX-2 function leads to elevated levels of PAR-5, enhanced chromatin and centrosome localization of PAR-5-GFP, and ultimately a reduction of ...


Sexual Dimorphism In Alcohol Induced Adipose Inflammation Relates To Liver Injury, Melissa A. Fulham, Pranoti Mandrekar Oct 2016

Sexual Dimorphism In Alcohol Induced Adipose Inflammation Relates To Liver Injury, Melissa A. Fulham, Pranoti Mandrekar

Open Access Articles

Alcoholic liver disease occurs due to chronic, heavy drinking and is driven both by metabolic alterations and immune cell activation. Women are at a higher risk than men for developing alcohol induced liver injury and this dimorphism is reflected in animal models of alcoholic liver disease. The importance of adipose tissue in alcoholic liver disease is emerging. Chronic alcohol consumption causes adipose tissue inflammation, which can influence liver injury. Sex differences in body fat composition are well known. However, it is still unclear if alcohol-induced adipose tissue inflammation occurs in a sex-dependent manner. Here we have employed the clinically relevant ...


Adipocyte-Specific Hypoxia-Inducible Gene 2 Promotes Fat Deposition And Diet-Induced Insulin Resistance, Marina Distefano, Rachel J. Roth Flach, Ozlem Senol-Cosar, Laura V. Danai, Joseph V. Virbasius, Sarah M. Nicoloro, Juerg R. Straubhaar, Sezin Dagdeviren, Martin Wabitsch, Olga T. Gupta, Jason K. Kim, Michael P. Czech Sep 2016

Adipocyte-Specific Hypoxia-Inducible Gene 2 Promotes Fat Deposition And Diet-Induced Insulin Resistance, Marina Distefano, Rachel J. Roth Flach, Ozlem Senol-Cosar, Laura V. Danai, Joseph V. Virbasius, Sarah M. Nicoloro, Juerg R. Straubhaar, Sezin Dagdeviren, Martin Wabitsch, Olga T. Gupta, Jason K. Kim, Michael P. Czech

Open Access Articles

OBJECTIVE: Adipose tissue relies on lipid droplet (LD) proteins in its role as a lipid-storing endocrine organ that controls whole body metabolism. Hypoxia-inducible Gene 2 (Hig2) is a recently identified LD-associated protein in hepatocytes that promotes hepatic lipid storage, but its role in the adipocyte had not been investigated. Here we tested the hypothesis that Hig2 localization to LDs in adipocytes promotes adipose tissue lipid deposition and systemic glucose homeostasis.

METHOD: White and brown adipocyte-deficient (Hig2fl/fl x Adiponection cre+) and selective brown/beige adipocyte-deficient (Hig2fl/fl x Ucp1 cre+) mice were generated to investigate the role of Hig2 in ...


An Alternative Splicing Program Promotes Adipose Tissue Thermogenesis, Santiago Vernia, Yvonne J. K. Edwards, Myoung Souk Han, Julie Cavanagh-Kyros, Tamera Barrett, Jason K. Kim, Roger J. Davis Sep 2016

An Alternative Splicing Program Promotes Adipose Tissue Thermogenesis, Santiago Vernia, Yvonne J. K. Edwards, Myoung Souk Han, Julie Cavanagh-Kyros, Tamera Barrett, Jason K. Kim, Roger J. Davis

University of Massachusetts Medical School Faculty Publications

Alternative pre-mRNA splicing expands the complexity of the transcriptome and controls isoform-specific gene expression. Whether alternative splicing contributes to metabolic regulation is largely unknown. Here we investigated the contribution of alternative splicing to the development of diet-induced obesity. We found that obesity-induced changes in adipocyte gene expression include alternative pre-mRNA splicing. Bioinformatics analysis associated part of this alternative splicing program with sequence specific NOVA splicing factors. This conclusion was confirmed by studies of mice with NOVA deficiency in adipocytes. Phenotypic analysis of the NOVA-deficient mice demonstrated increased adipose tissue thermogenesis and improved glycemia. We show that NOVA proteins mediate a ...


Viral Proteases As Drug Targets And The Mechanisms Of Drug Resistance: A Dissertation, Kuan-Hung Lin Sep 2016

Viral Proteases As Drug Targets And The Mechanisms Of Drug Resistance: A Dissertation, Kuan-Hung Lin

GSBS Dissertations and Theses

Viral proteases have been shown to be effective targets of anti-viral therapies for human immunodeficiency virus (HIV) and hepatitis C virus (HCV). However, under the pressure of therapy including protease inhibitors, the virus evolves to select drug resistance mutations both in the protease and substrates. In my thesis study, I aimed to understand the mechanisms of how this protease−substrate co-evolution contributes to drug resistance. Currently, there are no approved drugs against dengue virus (DENV); I investigated substrate recognition by DENV protease and designed cyclic peptides as inhibitors targeting the prime site of dengue protease.

First, I used X-ray crystallography ...


Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis Aug 2016

Suppression Of Ischemia In Arterial Occlusive Disease By Jnk-Promoted Native Collateral Artery Development, Kasmir Ramo, Koichi Sugamura, Siobhan M. Craige, John F. Keaney Jr., Roger J. Davis

Davis Lab Publications

Arterial occlusive diseases are major causes of morbidity and mortality. Blood flow to the affected tissue must be restored quickly if viability and function are to be preserved. We report that disruption of the mixed-lineage protein kinase (MLK) - cJun NH2-terminal kinase (JNK) signaling pathway in endothelial cells causes severe blockade of blood flow and failure to recover in the murine femoral artery ligation model of hindlimb ischemia. We show that the MLK-JNK pathway is required for the formation of native collateral arteries that can restore circulation following arterial occlusion. Disruption of the MLK-JNK pathway causes decreased Dll4/Notch signaling, excessive ...


Exploiting Dna Repair And Er Stress Response Pathways To Induce Apoptosis In Glioblastoma Multiforme: A Dissertation, Jessica L. Weatherbee Aug 2016

Exploiting Dna Repair And Er Stress Response Pathways To Induce Apoptosis In Glioblastoma Multiforme: A Dissertation, Jessica L. Weatherbee

GSBS Dissertations and Theses

Glioblastoma multiforme (GBM) is a deadly grade IV brain tumor characterized by a heterogeneous population of cells that are drug resistant, aggressive, and infiltrative. The current standard of care, which has not changed in over a decade, only provides GBM patients with 12-14 months survival post diagnosis. We asked if the addition of a novel endoplasmic reticulum (ER) stress inducing agent, JLK1486, to the standard chemotherapy, temozolomide (TMZ), which induces DNA double strand breaks (DSBs), would enhance TMZ’s efficacy. Because GBMs rely on the ER to mitigate their hypoxic environment and DNA repair to fix TMZ induced DSBs, we ...


Roles Of The Mother Centriole Appendage Protein Cenexin In Microtubule Organization During Cell Migration And Cell Division: A Dissertation, Hui-Fang Hung Aug 2016

Roles Of The Mother Centriole Appendage Protein Cenexin In Microtubule Organization During Cell Migration And Cell Division: A Dissertation, Hui-Fang Hung

GSBS Dissertations and Theses

Epithelial cells are necessary building blocks of the organs they line. Their apicalbasolateral polarity, characterized by an asymmetric distribution of cell components along their apical-basal axis, is a requirement for normal organ function. Although the centrosome, also known as the microtubule organizing center, is important in establishing cell polarity the mechanisms through which it achieves this remain unclear. It has been suggested that the centrosome influences cell polarity through microtubule cytoskeleton organization and endosome trafficking. In the first chapter of this thesis, I summarize the current understanding of the mechanisms regulating cell polarity and review evidence for the role of ...


Advances In Gene Therapy For Diseases Of The Eye, Lolita Petit, Hemant Khanna, Claudio Punzo Aug 2016

Advances In Gene Therapy For Diseases Of The Eye, Lolita Petit, Hemant Khanna, Claudio Punzo

UMass Metabolic Network Publications

Over the last few years, huge progress has been made with regard to the understanding of molecular mechanisms underlying the pathogenesis of neurodegenerative diseases of the eye. Such knowledge has led to the development of gene therapy approaches to treat these devastating disorders. Challenges regarding the efficacy and efficiency of therapeutic gene delivery have driven the development of novel therapeutic approaches, which continue to evolve the field of ocular gene therapy. In this review article, we will discuss the evolution of preclinical and clinical strategies that have improved gene therapy in the eye, showing that treatment of vision loss has ...


Protein Kinase Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (Map4k4) Promotes Obesity-Induced Hyperinsulinemia, Rachel J. Roth Flach, Laura V. Danai, Marina Distefano, Mark Kelly, Lorena Garcia Menendez, Agata Jurczyk, Rohit B. Sharma, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Rita Bortell, Laura C. Alonso, Michael P. Czech Jul 2016

Protein Kinase Mitogen-Activated Protein Kinase Kinase Kinase Kinase 4 (Map4k4) Promotes Obesity-Induced Hyperinsulinemia, Rachel J. Roth Flach, Laura V. Danai, Marina Distefano, Mark Kelly, Lorena Garcia Menendez, Agata Jurczyk, Rohit B. Sharma, Dae Young Jung, Jong Hun Kim, Jason K. Kim, Rita Bortell, Laura C. Alonso, Michael P. Czech

Open Access Articles

Previous studies revealed a paradox whereby mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) acted as a negative regulator of insulin sensitivity in chronically obese mice, yet systemic deletion of Map4k4 did not improve glucose tolerance. Here, we report markedly reduced glucose-responsive plasma insulin and C-peptide levels in whole body Map4k4-depleted mice (M4K4 iKO) as well as an impaired first phase of insulin secretion from islets derived from M4K4 iKO mice ex vivo After long-term high fat diet (HFD), M4K4 iKO mice pancreata also displayed reduced beta cell mass, fewer proliferating beta cells and reduced islet-specific gene mRNA expression compared ...


A Role For Tnmd In Adipocyte Differentiation And Adipose Tissue Function: A Dissertation, Ozlem Senol-Cosar Jun 2016

A Role For Tnmd In Adipocyte Differentiation And Adipose Tissue Function: A Dissertation, Ozlem Senol-Cosar

GSBS Dissertations and Theses

Adipose tissue is one of the most dynamic tissues in the body and is vital for metabolic homeostasis. In the case of excess nutrient uptake, adipose tissue expands to store excess energy in the form of lipids, and in the case of reduced nutrient intake, adipose tissue can shrink and release this energy. Adipocytes are most functional when the balance between these two processes is intact. To understand the molecular mechanisms that drive insulin resistance or conversely preserve the metabolically healthy state in obese individuals, our laboratory performed a screen for differentially regulated adipocyte genes in insulin resistant versus insulin ...


Promoter-Enhancer Looping At The Pparγ2 Locus During Adipogenic Differentiation Requires The Prmt5 Methyltransferase, Scott E. Leblanc, Qiong Wu, Pallavi Lamba, Said Sif, Anthony N. Imbalzano Jun 2016

Promoter-Enhancer Looping At The Pparγ2 Locus During Adipogenic Differentiation Requires The Prmt5 Methyltransferase, Scott E. Leblanc, Qiong Wu, Pallavi Lamba, Said Sif, Anthony N. Imbalzano

Imbalzano Lab Publications

PPARγ2 is a critical lineage-determining transcription factor that is essential for adipogenic differentiation. Here we report characterization of the three-dimensional structure of the PPARγ2 locus after the onset of adipogenic differentiation and the mechanisms by which it forms. We identified a differentiation-dependent loop between the PPARγ2 promoter and an enhancer sequence 10 kb upstream that forms at the onset of PPARγ2 expression. The arginine methyltransferase Prmt5 was required for loop formation, and overexpression of Prmt5 resulted in premature loop formation and earlier onset of PPARγ2 expression. Kinetic studies of regulatory factor interactions at the PPARγ2 promoter and enhancer revealed enhanced ...