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2017

Cell Biology

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Articles 1 - 30 of 114

Full-Text Articles in Molecular Biology

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O'Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres Dec 2017

Serine-Dependent Sphingolipid Synthesis Is A Metabolic Liability Of Aneuploid Cells, Sunyoung Hwang, H. Tobias Gustafsson, Ciara O'Sullivan, Gianna Bisceglia, Xinhe Huang, Christian Klose, Andrej Schevchenko, Robert C. Dickson, Paola Cavaliere, Noah Dephoure, Eduardo M. Torres

University of Massachusetts Medical School Faculty Publications

Aneuploidy disrupts cellular homeostasis. However, the molecular mechanisms underlying the physiological responses and adaptation to aneuploidy are not well understood. Deciphering these mechanisms is important because aneuploidy is associated with diseases, including intellectual disability and cancer. Although tumors and mammalian aneuploid cells, including several cancer cell lines, show altered levels of sphingolipids, the role of sphingolipids in aneuploidy remains unknown. Here, we show that ceramides and long-chain bases, sphingolipid molecules that slow proliferation and promote survival, are increased by aneuploidy. Sphingolipid levels are tightly linked to serine synthesis, and inhibiting either serine or sphingolipid synthesis can specifically impair the fitness ...


Reconciling Contradictory Findings: Glucose Transporter 1 (Glut1) Functions As An Oligomer Of Allosteric, Alternating Access Transporters, Kenneth P. Lloyd, Ogooluwa A. Ojelabi, Julie K. De Zutter, Anthony Carruthers Dec 2017

Reconciling Contradictory Findings: Glucose Transporter 1 (Glut1) Functions As An Oligomer Of Allosteric, Alternating Access Transporters, Kenneth P. Lloyd, Ogooluwa A. Ojelabi, Julie K. De Zutter, Anthony Carruthers

UMass Metabolic Network Publications

Recent structural studies suggest that glucose transporter 1 (GLUT1)-mediated sugar transport is mediated by an alternating access transporter that successively presents exofacial (e2) and endofacial (e1) substrate-binding sites. Transport studies, however, indicate multiple, interacting (allosteric), and co-existent, exo- and endofacial GLUT1 ligand-binding sites. The present study asks whether these contradictory conclusions result from systematic analytical error or reveal a more fundamental relationship between transporter structure and function. Here, homology modeling supported the alternating access transporter model for sugar transport by confirming at least four GLUT1 conformations, the so-called outward, outward-occluded, inward-occluded, and inward GLUT1 conformations. Results from docking analysis ...


Role Of Ezrin In Colorectal Cancer Cell Survival Regulation, Premila Leiphrakpam Dec 2017

Role Of Ezrin In Colorectal Cancer Cell Survival Regulation, Premila Leiphrakpam

Theses & Dissertations

Colorectal cancer (CRC) is the second most common cause of cancer related deaths in the United States, mainly due to metastasis to the distant organ sites. However, the molecular basis of CRC metastasis is poorly understood. Therefore, identification and characterization of novel potential anti-cancer therapeutic targets CRC is of urgent need. Utilizing a 2D-DIGE proteomics approach ezrin was identified as a protein that is differentially expressed between primary colon tumors xenografts, orthotopically implanted in athymic nude mice, and corresponding and liver metastatic deposits. Ezrin, a cytoskeletal protein belonging to the ezrin–radixin–moesin (ERM) family plays important roles in cell ...


Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell Dec 2017

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.

Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the ...


The Alpha6beta4 Integrin Promotes Resistance To Ferroptosis, Caitlin W. Brown, John J. Amante, Hira Lal Goel, Arthur M. Mercurio Dec 2017

The Alpha6beta4 Integrin Promotes Resistance To Ferroptosis, Caitlin W. Brown, John J. Amante, Hira Lal Goel, Arthur M. Mercurio

UMass Metabolic Network Publications

Increases in lipid peroxidation can cause ferroptosis, a form of cell death triggered by inhibition of glutathione peroxidase 4 (GPX4), which catalyzes the reduction of lipid peroxides and is a target of ferroptosis inducers, such as erastin. The alpha6beta4 integrin protects adherent epithelial and carcinoma cells from ferroptosis induced by erastin. In addition, extracellular matrix (ECM) detachment is a physiologic trigger of ferroptosis, which is evaded by alpha6beta4. The mechanism that enables alpha6beta4 to evade ferroptosis involves its ability to protect changes in membrane lipids that are proferroptotic. Specifically, alpha6beta4-mediated activation of Src and STAT3 suppresses expression of ACSL4, an ...


Characterization Of Notch1 And Pi3k-Pten-Akt/Mtor Pathway Interaction In Head And Neck Squamous Cell Carcinoma, Kyriante' Henry Dec 2017

Characterization Of Notch1 And Pi3k-Pten-Akt/Mtor Pathway Interaction In Head And Neck Squamous Cell Carcinoma, Kyriante' Henry

UT GSBS Dissertations and Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) affects various mucosal sites of the upper aerodigestive tract, including the nasal and oral cavities, the nasopharynx, and the oropharynx. More than five hundred thousand new cases of HNSCC occurred in 2011 alone, with 50,000 reported cases in the United States. This trend made HNSCC the seventh most common non-skin cancer worldwide (Ferlay et al., 2015). Although significant epidemiological and pathological advancements have been made, survival rates have not improved much over the last 40 years, leaving a mortality rate that remains at approximately 50%. An unbiased drug screen demonstrated that HNSCC ...


Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon Dec 2017

Insights Into The Therapeutic Potential Of Salt Inducible Kinase 1: A Novel Mechanism Of Metabolic Control, Randi Fitzgibbon

UT GSBS Dissertations and Theses (Open Access)

Salt inducible kinase 1 (SIK1) has been considered a stress-inducible kinase since it was first cloned in 1999. Continued efforts since this time have been dedicated to characterizing the structure and function of SIK1. Such research has laid the ground work for our understanding of SIK1 action and regulation in tissue and stimuli dependent manners. The fundamental findings of this dissertation continue in this tradition and include investigations of SIK1 regulatory mechanisms in skeletal muscle cells, the cellular and physiological effects of SIK1 loss of function in vitro and in vivo, and intracellular metabolic and mitochondrial regulation by this kinase ...


Endocytic Trafficking Of The Amyloid Precursor Protein In Rat Cortical Neurons, Sahily Reyes Dec 2017

Endocytic Trafficking Of The Amyloid Precursor Protein In Rat Cortical Neurons, Sahily Reyes

UT GSBS Dissertations and Theses (Open Access)

Amyloid-beta (Aβ) aggregation and deposition into extracellular plaques is a hallmark of the most common forms of dementia, including Alzheimer’s disease. The Aβ-containing plaques result from pathogenic cleavage of amyloid precursor protein (APP) by secretases resulting in intracellular production of Aβ peptides that are secreted and accumulate extracellularly. Despite considerable progress towards understanding APP processing and Aβ aggregation, the mechanisms underlying endosomal production of Aβ peptides and their secretion remain unclear. Using endosomes isolated from cultured primary neurons, we determined that the trafficking of APP from the endosomal membrane into internal vesicles of late endosome/multivesicular bodies (MVB) is ...


Determination Of The Effects Of Different Maillard Reaction Products On The Taxonomic Composition Of The Gut Microbiota, Nesreen Hamdan Aljahdali Dec 2017

Determination Of The Effects Of Different Maillard Reaction Products On The Taxonomic Composition Of The Gut Microbiota, Nesreen Hamdan Aljahdali

Theses and Dissertations

The Maillard Reaction (MR) is a non-enzymatic chemical reaction which results in linkage between the amino group of amino acids and the carbonyl group of reduced sugars. This reaction generates Maillard reaction products (MRPs) which are not present naturally in foods, and are responsible for a range of colors, odors, flavors, and other sensory properties. Conflicting reports of MRPs impacts on human health are probably due to the fact that bioconversion of these digestible molecules by the gut microbiota has been marginally taken into account. This study aimed to determine the effects of different MRPs on rodent’s gut microbiota ...


Detection Of Survival And Proliferation Of Sulfate Reducers Under Simulated Martian Atmospheric And Soil Conditions, Sergio Mosquera Mora Dec 2017

Detection Of Survival And Proliferation Of Sulfate Reducers Under Simulated Martian Atmospheric And Soil Conditions, Sergio Mosquera Mora

Theses and Dissertations

Numerous studies have tried to determine the survivability and proliferation of microorganisms under simulated Martian conditions. Furthermore, most of them have been focused on the ability of these microbes to cope with high brines’ salt (NaCl) concentrations inherent of the Martian surface. However, there are not studies related to the ability of bacteria to survive on subsurface environments that have increasing concentrations of sulfate compounds. For this research, a group of microorganisms known as sulfate-reducing bacteria or simply sulfate reducers were chosen due to their ability to use sulfate compounds as terminal electron acceptors to produce metabolic energy, their tolerance ...


Cellular Mechanisms Of Ionoregulation In The Gill Of Japanese Medaka And Rainbow Trout, Rebecca Jo Bollinger Dec 2017

Cellular Mechanisms Of Ionoregulation In The Gill Of Japanese Medaka And Rainbow Trout, Rebecca Jo Bollinger

Theses and Dissertations

Euryhaline fishes are capable of adapting to a wide range of salinities such as freshwater, brackish water or seawater. Through the combined effort of the gill, kidney and intestine, they are able to osmoregulate to maintain a constant internal hydromineral balance. As the gill is in direct contact with the external environment, it is continuously working to maintain ion and acid/base balance, gas exchange and eliminate nitrogenous waste. Fish in freshwater are subjected to osmotic water gain and diffusional ion loss across the gill and experience the opposite in seawater. Therefore, the gill exhibits extreme plasticity when experiencing a ...


Temporal Regulation Of Chromatin During Myoblast Differentiation, Akihito Harada, Yasuyuki Ohkawa, Anthony N. Imbalzano Dec 2017

Temporal Regulation Of Chromatin During Myoblast Differentiation, Akihito Harada, Yasuyuki Ohkawa, Anthony N. Imbalzano

UMass Metabolic Network Publications

The commitment to and execution of differentiation programmes involves a significant change in gene expression in the precursor cell to facilitate development of the mature cell type. In addition to being regulated by lineage-determining and auxiliary transcription factors that drive these changes, the structural status of the chromatin has a considerable impact on the transcriptional competence of differentiation-specific genes, which is clearly demonstrated by the large number of cofactors and the extraordinary complex mechanisms by which these genes become activated. The terminal differentiation of myoblasts to myotubes and mature skeletal muscle is an excellent system to illustrate these points. The ...


Role Of Heat Shock Transcription Factor 1 In Ovarian Cancer Epithelial-Mesenchymal Transition And Drug Sensitivity, Chase David Powell Nov 2017

Role Of Heat Shock Transcription Factor 1 In Ovarian Cancer Epithelial-Mesenchymal Transition And Drug Sensitivity, Chase David Powell

Graduate Theses and Dissertations

The heat shock response (HSR) is a robust cellular reaction to mitigate protein damage from heat and other challenges to the proteome. This protective molecular program in humans is controlled by heat shock transcription factor 1 (HSF1). Activation of HSF1 leads to the induction of an array of cytoprotective genes, many of which code for chaperones. These chaperones, known as heat shock proteins (HSPs), are responsible for maintaining the functional integrity of the proteome. HSPs achieve this by promoting proper folding and assembly of nascent proteins, refolding denatured proteins, and processing for degradation proteins and aggregates which cannot be returned ...


Jnk Promotes Epithelial Cell Anoikis By Transcriptional And Post-Translational Regulation Of Bh3-Only Proteins, Nomeda Girnius, Roger J. Davis Nov 2017

Jnk Promotes Epithelial Cell Anoikis By Transcriptional And Post-Translational Regulation Of Bh3-Only Proteins, Nomeda Girnius, Roger J. Davis

UMass Metabolic Network Publications

Developmental morphogenesis, tissue injury, and oncogenic transformation can cause the detachment of epithelial cells. These cells are eliminated by a specialized form of apoptosis (anoikis). While the processes that contribute to this form of cell death have been studied, the underlying mechanisms remain unclear. Here, we tested the role of the cJUN NH2-terminal kinase (JNK) signaling pathway using murine models with compound JNK deficiency in mammary and kidney epithelial cells. These studies demonstrated that JNK is required for efficient anoikis in vitro and in vivo. Moreover, JNK-promoted anoikis required pro-apoptotic members of the BCL2 family of proteins. We show that ...


The Role Of Sgs1 And Exo1 In The Maintenance Of Genome Stability., Lillian Campos-Doerfler Nov 2017

The Role Of Sgs1 And Exo1 In The Maintenance Of Genome Stability., Lillian Campos-Doerfler

Graduate Theses and Dissertations

Genome instability is a hallmark of human cancers. Patients with Bloom’s syndrome, a rare chromosome breakage syndrome caused by inactivation of the RecQ helicase BLM, result in phenotypes associated with accelerated aging and develop cancer at a very young age. Patients with Bloom’s syndrome exhibit hyper-recombination, but the role of BLM and increased genomic instability is not fully characterized. Sgs1, the only member of the RecQ family of DNA helicases in Saccharomyces cerevisiae, is known to act both in early and late stages of homology-dependent repair of DNA damage. Exo1, a 5′–3′ exonuclease, first discovered to play ...


Bivalent Epigenetic Control Of Oncofetal Gene Expression In Cancer, Sayyed K. Zaidi, Seth E. Frietze, Jonathan A. Gordon, Jessica L. Heath, Terri Messier, Deli Hong, Joseph R. Boyd, Mingu Kang, Anthony N. Imbalzano, Jane B. Lian, Janet L. Stein, Gary S. Stein Nov 2017

Bivalent Epigenetic Control Of Oncofetal Gene Expression In Cancer, Sayyed K. Zaidi, Seth E. Frietze, Jonathan A. Gordon, Jessica L. Heath, Terri Messier, Deli Hong, Joseph R. Boyd, Mingu Kang, Anthony N. Imbalzano, Jane B. Lian, Janet L. Stein, Gary S. Stein

UMass Metabolic Network Publications

Multiple mechanisms of epigenetic control that include DNA methylation, histone modification, noncoding RNAs, and mitotic gene bookmarking play pivotal roles in stringent gene regulation during lineage commitment and maintenance. Experimental evidence indicates that bivalent chromatin domains, i.e., genome regions that are marked by both H3K4me3 (activating) and H3K27me3 (repressive) histone modifications, are a key property of pluripotent stem cells. Bivalency of developmental genes during the G1 phase of the pluripotent stem cell cycle contributes to cell fate decisions. Recently, some cancer types have been shown to exhibit partial recapitulation of bivalent chromatin modifications that are lost along with pluripotency ...


Casein Kinase 2-Mediated Phosphorylation Of Brahma-Related Gene 1 Controls Myoblast Proliferation And Contributes To Swi/Snf Complex Composition, Teresita Padilla-Benavides, Brian T. Nasipak, Amanda L. Paskavitz, Dominic T. Haokip, Jake M. Schnabl, Jeffrey A. Nickerson, Anthony N. Imbalzano Nov 2017

Casein Kinase 2-Mediated Phosphorylation Of Brahma-Related Gene 1 Controls Myoblast Proliferation And Contributes To Swi/Snf Complex Composition, Teresita Padilla-Benavides, Brian T. Nasipak, Amanda L. Paskavitz, Dominic T. Haokip, Jake M. Schnabl, Jeffrey A. Nickerson, Anthony N. Imbalzano

UMass Metabolic Network Publications

Transcriptional regulation is modulated in part by chromatin-remodeling enzymes that control gene accessibility by altering chromatin compaction or nucleosome positioning. Brahma-related gene 1 (Brg1), a catalytic subunit of the mammalian SWI/SNF chromatin-remodeling enzymes, is required for both myoblast proliferation and differentiation, and the control of Brg1 phosphorylation by calcineurin, PKCbeta1, and p38 regulates the transition to differentiation. However, we hypothesized that Brg1 activity might be regulated by additional kinases. Here, we report that Brg1 is also a target of casein kinase 2 (CK2), a serine/threonine kinase, in proliferating myoblasts. We found that CK2 interacts with Brg1, and mutation ...


Mitochondrial Stress Restores The Heat Shock Response And Prevents Proteostasis Collapse During Aging, Johnathan Labbadia, Renee M. Brielmann, Mario F. Neto, Yi-Fan Lin, Cole M. Haynes, Richard I. Morimoto Nov 2017

Mitochondrial Stress Restores The Heat Shock Response And Prevents Proteostasis Collapse During Aging, Johnathan Labbadia, Renee M. Brielmann, Mario F. Neto, Yi-Fan Lin, Cole M. Haynes, Richard I. Morimoto

UMass Metabolic Network Publications

In Caenorhabditis elegans, the programmed repression of the heat shock response (HSR) accompanies the transition to reproductive maturity, leaving cells vulnerable to environmental stress and protein aggregation with age. To identify the factors driving this event, we performed an unbiased genetic screen for suppressors of stress resistance and identified the mitochondrial electron transport chain (ETC) as a central regulator of the age-related decline of the HSR and cytosolic proteostasis. Mild downregulation of ETC activity, either by genetic modulation or exposure to mitochondria-targeted xenobiotics, maintained the HSR in adulthood by increasing HSF-1 binding and RNA polymerase II recruitment at HSF-1 target ...


Decreasing Cb1 Receptor Signaling In Kupffer Cells Improves Insulin Sensitivity In Obese Mice, Tony Jourdan, Sarah M. Nicoloro, Zhou Zhou, Yuefei Shen, Jie Liu, Nathan J. Coffey, Resat Cinar, Grzegorz Godlewski, Bin Gao, Myriam Aouadi, Michael P. Czech, George Kunos Nov 2017

Decreasing Cb1 Receptor Signaling In Kupffer Cells Improves Insulin Sensitivity In Obese Mice, Tony Jourdan, Sarah M. Nicoloro, Zhou Zhou, Yuefei Shen, Jie Liu, Nathan J. Coffey, Resat Cinar, Grzegorz Godlewski, Bin Gao, Myriam Aouadi, Michael P. Czech, George Kunos

UMass Metabolic Network Publications

OBJECTIVE: Obesity-induced accumulation of ectopic fat in the liver is thought to contribute to the development of insulin resistance, and increased activity of hepatic CB1R has been shown to promote both processes. However, lipid accumulation in liver can be experimentally dissociated from insulin resistance under certain conditions, suggesting the involvement of additional mechanisms. Obesity is also associated with pro-inflammatory changes which, in turn, can promote insulin resistance. Kupffer cells (KCs), the liver's resident macrophages, are the major source of pro-inflammatory cytokines in the liver, such as TNF-alpha, which has been shown to inhibit insulin signaling in multiple cell types ...


Xist Rna: A Window Into The Broader Role Of Rna In Nuclear Chromosome Architecture, Kevin Creamer, Jeanne B. Lawrence Nov 2017

Xist Rna: A Window Into The Broader Role Of Rna In Nuclear Chromosome Architecture, Kevin Creamer, Jeanne B. Lawrence

Open Access Articles

XIST RNA triggers the transformation of an active X chromosome into a condensed, inactive Barr body and therefore provides a unique window into transitions of higher-order chromosome architecture. Despite recent progress, how XIST RNA localizes and interacts with the X chromosome remains poorly understood. Genetic engineering of XIST into a trisomic autosome demonstrates remarkable capacity of XIST RNA to localize and comprehensively silence that autosome. Thus, XIST does not require X chromosome-specific sequences but operates on mechanisms available genome-wide. Prior results suggested XIST localization is controlled by attachment to the insoluble nuclear scaffold. Our recent work affirms that scaffold attachment ...


Hdac3 Regulates Lymphovenous And Lymphatic Valve Formation, Harish P. Janardhan, Zachary J. Milstone, Masahiro Shin, Nathan D. Lawson, John F. Keaney Jr., Chinmay M. Trivedi Nov 2017

Hdac3 Regulates Lymphovenous And Lymphatic Valve Formation, Harish P. Janardhan, Zachary J. Milstone, Masahiro Shin, Nathan D. Lawson, John F. Keaney Jr., Chinmay M. Trivedi

UMass Metabolic Network Publications

Lymphedema, the most common lymphatic anomaly, involves defective lymphatic valve development; yet the epigenetic modifiers underlying lymphatic valve morphogenesis remain elusive. Here, we showed that during mouse development, the histone-modifying enzyme histone deacetylase 3 (Hdac3) regulates the formation of both lymphovenous valves, which maintain the separation of the blood and lymphatic vascular systems, and the lymphatic valves. Endothelium-specific ablation of Hdac3 in mice led to blood-filled lymphatic vessels, edema, defective lymphovenous valve morphogenesis, improper lymphatic drainage, defective lymphatic valve maturation, and complete lethality. Hdac3-deficient lymphovenous valves and lymphatic vessels exhibited reduced expression of the transcription factor Gata2 and its target ...


Association Of Multiorgan Computed Tomographic Phenomap With Adverse Cardiovascular Health Outcomes: The Framingham Heart Study, Ravi V. Shah, Ashish S. Yeri, Venkatesh L. Murthy, Joe M. Massaro, Ralph Sr. D'Agostino, Jane E. Freedman, Michelle T. Long, Caroline S. Fox, Saumya Das, Emelia J. Benjamin, Ramachandran S. Vasan, Christopher J. O'Donnell, Udo Hoffmann Nov 2017

Association Of Multiorgan Computed Tomographic Phenomap With Adverse Cardiovascular Health Outcomes: The Framingham Heart Study, Ravi V. Shah, Ashish S. Yeri, Venkatesh L. Murthy, Joe M. Massaro, Ralph Sr. D'Agostino, Jane E. Freedman, Michelle T. Long, Caroline S. Fox, Saumya Das, Emelia J. Benjamin, Ramachandran S. Vasan, Christopher J. O'Donnell, Udo Hoffmann

UMass Metabolic Network Publications

Importance: Increased ability to quantify anatomical phenotypes across multiple organs provides the opportunity to assess their cumulative ability to identify individuals at greatest susceptibility for adverse outcomes.

Objective: To apply unsupervised machine learning to define the distribution and prognostic importance of computed tomography-based multiorgan phenotypes associated with adverse health outcomes.

Design, Setting, and Participants: This asymptomatic community-based cohort study included 2924 Framingham Heart Study participants between July 2002 and April 2005 undergoing computed tomographic imaging of the chest and abdomen. Participants are from the offspring and third-generation cohorts.

Exposures: Eleven computed tomography-based measures of valvular/vascular calcification, adiposity, and muscle ...


Role Of Granulocyte-Macrophage Colony-Stimulating Factor Production By T Cells During Mycobacterium Tuberculosis Infection, Alissa C. Rothchild, Britni L. Stowell, Girija Goyal, Claudio Nunes-Alves, Qianting Yang, Kadamba Papavinasasundaram, Christopher M. Sassetti, Glenn Dranoff, Xinchun Chen, Jinhee Lee, Samuel M. Behar Oct 2017

Role Of Granulocyte-Macrophage Colony-Stimulating Factor Production By T Cells During Mycobacterium Tuberculosis Infection, Alissa C. Rothchild, Britni L. Stowell, Girija Goyal, Claudio Nunes-Alves, Qianting Yang, Kadamba Papavinasasundaram, Christopher M. Sassetti, Glenn Dranoff, Xinchun Chen, Jinhee Lee, Samuel M. Behar

UMass Metabolic Network Publications

Mice deficient for granulocyte-macrophage colony-stimulating factor (GM-CSF(-/-)) are highly susceptible to infection with Mycobacterium tuberculosis, and clinical data have shown that anti-GM-CSF neutralizing antibodies can lead to increased susceptibility to tuberculosis in otherwise healthy people. GM-CSF activates human and murine macrophages to inhibit intracellular M. tuberculosis growth. We have previously shown that GM-CSF produced by iNKT cells inhibits growth of M. tuberculosis However, the more general role of T cell-derived GM-CSF during infection has not been defined and how GM-CSF activates macrophages to inhibit bacterial growth is unknown. Here we demonstrate that, in addition to nonconventional T cells, conventional T ...


Age-Associated Microrna Expression In Human Peripheral Blood Is Associated With All-Cause Mortality And Age-Related Traits, Tianxiao Huan, George Chen, Chunyu Liu, Anindya Bhattacharya, Jian Rong, Brian H. Chen, Sudha Seshadri, Kahraman Tanriverdi, Jane E. Freedman, Martin G. Larson, Joanne M. Murabito, Daniel Levy Oct 2017

Age-Associated Microrna Expression In Human Peripheral Blood Is Associated With All-Cause Mortality And Age-Related Traits, Tianxiao Huan, George Chen, Chunyu Liu, Anindya Bhattacharya, Jian Rong, Brian H. Chen, Sudha Seshadri, Kahraman Tanriverdi, Jane E. Freedman, Martin G. Larson, Joanne M. Murabito, Daniel Levy

UMass Metabolic Network Publications

Recent studies provide evidence of correlations of DNA methylation and expression of protein-coding genes with human aging. The relations of microRNA expression with age and age-related clinical outcomes have not been characterized thoroughly. We explored associations of age with whole-blood microRNA expression in 5221 adults and identified 127 microRNAs that were differentially expressed by age at P < 3.3 x 10(-4) (Bonferroni-corrected). Most microRNAs were underexpressed in older individuals. Integrative analysis of microRNA and mRNA expression revealed changes in age-associated mRNA expression possibly driven by age-associated microRNAs in pathways that involve RNA processing, translation, and immune function. We fitted a linear model to predict 'microRNA age' that incorporated expression levels of 80 microRNAs. MicroRNA age correlated modestly with predicted age from DNA methylation (r = 0.3) and mRNA expression (r = 0.2), suggesting that microRNA age may complement mRNA and epigenetic age prediction models. We used the difference between microRNA age and chronological age as a biomarker of accelerated aging (Deltaage) and found that Deltaage was associated with all-cause mortality (hazards ratio 1.1 per year difference, P = 4.2 x 10(-5) adjusted for sex and chronological age). Additionally, Deltaage was associated with coronary heart disease, hypertension, blood pressure, and glucose levels. In conclusion, we constructed a microRNA age prediction model based on whole-blood microRNA expression profiling. Age-associated microRNAs and their targets have potential utility to detect accelerated aging and to predict risks for age-related diseases. Wiley and Sons Ltd.


A Role For Tau Protein In Maintaining Ribosomal Dna Stability And Cytidine Deaminase-Deficient Cell Survival, Elias Bou Samra, Geraldine Buhagiar-Labarchede, Christelle Machon, Jerome Guitton, Rosine Onclercq-Delic, Michael R. Green, Olivier Alibert, Claude Gazin, Xavier Veaute, Mounira Amor-Gueret Sep 2017

A Role For Tau Protein In Maintaining Ribosomal Dna Stability And Cytidine Deaminase-Deficient Cell Survival, Elias Bou Samra, Geraldine Buhagiar-Labarchede, Christelle Machon, Jerome Guitton, Rosine Onclercq-Delic, Michael R. Green, Olivier Alibert, Claude Gazin, Xavier Veaute, Mounira Amor-Gueret

Open Access Articles

Cells from Bloom's syndrome patients display genome instability due to a defective BLM and the downregulation of cytidine deaminase. Here, we use a genome-wide RNAi-synthetic lethal screen and transcriptomic profiling to identify genes enabling BLM-deficient and/or cytidine deaminase-deficient cells to tolerate constitutive DNA damage and replication stress. We found a synthetic lethal interaction between cytidine deaminase and microtubule-associated protein Tau deficiencies. Tau is overexpressed in cytidine deaminase-deficient cells, and its depletion worsens genome instability, compromising cell survival. Tau is recruited, along with upstream-binding factor, to ribosomal DNA loci. Tau downregulation decreases upstream binding factor recruitment, ribosomal RNA synthesis ...


A Protein Scaffold Coordinates Src-Mediated Jnk Activation In Response To Metabolic Stress, Shashi Kant, Claire L. Standen, Caroline Morel, Dae Young Jung, Jason K. Kim, Wojciech Swat, Richard A. Flavell, Roger J. Davis Sep 2017

A Protein Scaffold Coordinates Src-Mediated Jnk Activation In Response To Metabolic Stress, Shashi Kant, Claire L. Standen, Caroline Morel, Dae Young Jung, Jason K. Kim, Wojciech Swat, Richard A. Flavell, Roger J. Davis

UMass Metabolic Network Publications

Obesity is a major risk factor for the development of metabolic syndrome and type 2 diabetes. How obesity contributes to metabolic syndrome is unclear. Free fatty acid (FFA) activation of a non-receptor tyrosine kinase (SRC)-dependent cJun NH2-terminal kinase (JNK) signaling pathway is implicated in this process. However, the mechanism that mediates SRC-dependent JNK activation is unclear. Here, we identify a role for the scaffold protein JIP1 in SRC-dependent JNK activation. SRC phosphorylation of JIP1 creates phosphotyrosine interaction motifs that bind the SH2 domains of SRC and the guanine nucleotide exchange factor VAV. These interactions are required for SRC-induced activation ...


Exploring Biological Heterogeneity And Its Consequences At Tissue And Cellular Scales Through Mathematical And Computational Modeling, Romica Kerketta Sep 2017

Exploring Biological Heterogeneity And Its Consequences At Tissue And Cellular Scales Through Mathematical And Computational Modeling, Romica Kerketta

Biomedical Sciences ETDs

This dissertation explores the effects of heterogeneity across different biological scales in cancer as well as normal cells. At the tissue scale, we investigated the variability present in the tumor microenvironment and its effect on patient chemotherapeutic outcomes using a mathematical model of drug transport. We found that parameters such as tumor blood perfusion and radius of blood vessel had an impact on the tumor cytotoxicity. This indicated that the physical microenvironment of the tumor is an important regulator of the tumor response to chemotherapy. At the cellular scale, we investigated the heterogeneity present on the membrane landscape of ErbB2 ...


A Synthetic Biology Approach To Probing Nucleosome Symmetry, Yuichi Ichikawa, Caitlin M. Connolly, Hsin-Jung Chou, Yuanyuan Chen, Upasna Sharma, Hsuiyi V. Chen, Vineeta Bajaj, Daniel Na. Bolon, Oliver J. Rando, Paul D. Kaufman Sep 2017

A Synthetic Biology Approach To Probing Nucleosome Symmetry, Yuichi Ichikawa, Caitlin M. Connolly, Hsin-Jung Chou, Yuanyuan Chen, Upasna Sharma, Hsuiyi V. Chen, Vineeta Bajaj, Daniel Na. Bolon, Oliver J. Rando, Paul D. Kaufman

UMass Metabolic Network Publications

The repeating subunit of chromatin, the nucleosome, includes two copies of each of the four core histones, and several recent studies have reported that asymmetrically-modified nucleosomes occur at regulatory elements in vivo. To probe the mechanisms by which histone modifications are read out, we designed an obligate pair of H3 heterodimers, termed H3X and H3Y, which we extensively validated genetically and biochemically. Comparing the effects of asymmetric histone tail point mutants with those of symmetric double mutants revealed that a single methylated H3K36 per nucleosome was sufficient to silence cryptic transcription in vivo. We also demonstrate the utility of this ...


A Dual Role Of Caspase-8 In Triggering And Sensing Proliferation-Associated Dna Damage, A Key Determinant Of Liver Cancer Development, Yannick Boege, Roger J. Davis, Achim Weber Sep 2017

A Dual Role Of Caspase-8 In Triggering And Sensing Proliferation-Associated Dna Damage, A Key Determinant Of Liver Cancer Development, Yannick Boege, Roger J. Davis, Achim Weber

UMass Metabolic Network Publications

Concomitant hepatocyte apoptosis and regeneration is a hallmark of chronic liver diseases (CLDs) predisposing to hepatocellular carcinoma (HCC). Here, we mechanistically link caspase-8-dependent apoptosis to HCC development via proliferation- and replication-associated DNA damage. Proliferation-associated replication stress, DNA damage, and genetic instability are detectable in CLDs before any neoplastic changes occur. Accumulated levels of hepatocyte apoptosis determine and predict subsequent hepatocarcinogenesis. Proliferation-associated DNA damage is sensed by a complex comprising caspase-8, FADD, c-FLIP, and a kinase-dependent function of RIPK1. This platform requires a non-apoptotic function of caspase-8, but no caspase-3 or caspase-8 cleavage. It may represent a DNA damage-sensing mechanism in ...


The N-Terminus Of Ift46 Mediates Intraflagellar Transport Of Outer Arm Dynein And Its Cargo-Adaptor Oda16, Yuqing Hou, George B. Witman Sep 2017

The N-Terminus Of Ift46 Mediates Intraflagellar Transport Of Outer Arm Dynein And Its Cargo-Adaptor Oda16, Yuqing Hou, George B. Witman

Radiology Publications and Presentations

Cilia are assembled via intraflagellar transport (IFT). The IFT machinery is composed of motors and multi-subunit particles, termed IFT-A and IFT-B, that carry cargo into the cilium. Knowledge of how the IFT subunits interact with their cargo is of critical importance for understanding how the unique ciliary domain is established. We previously reported a Chlamydomonas mutant, ift46-1, that fails to express the IFT-B protein IFT46, has greatly reduced levels of other IFT-B proteins, and assembles only very short flagella. A spontaneous suppression of ift46-1 restored IFT-B levels and enabled growth of longer flagella, but the flagella lacked outer dynein arms ...