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Full-Text Articles in Cell Biology

Genome-Wide Crispr Screens For Shiga Toxins And Ricin Reveal Golgi Proteins Critical For Glycosylation, Songhai Tian, Khaja Muneeruddin, Mei Yuk Choi, Liang Tao, Robiul H. Bhuiyan, Yuhsuke Ohmi, Keiko Furukawa, Koichi Furukawa, Sebastian Boland, Scott A. Shaffer, Rosalyn M. Adam, Min Dong Nov 2018

Genome-Wide Crispr Screens For Shiga Toxins And Ricin Reveal Golgi Proteins Critical For Glycosylation, Songhai Tian, Khaja Muneeruddin, Mei Yuk Choi, Liang Tao, Robiul H. Bhuiyan, Yuhsuke Ohmi, Keiko Furukawa, Koichi Furukawa, Sebastian Boland, Scott A. Shaffer, Rosalyn M. Adam, Min Dong

Open Access Articles

Glycosylation is a fundamental modification of proteins and membrane lipids. Toxins that utilize glycans as their receptors have served as powerful tools to identify key players in glycosylation processes. Here, we carried out Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9-mediated genome-wide loss-of-function screens using two related bacterial toxins, Shiga-like toxins (Stxs) 1 and 2, which use a specific glycolipid, globotriaosylceramide (Gb3), as receptors, and the plant toxin ricin, which recognizes a broad range of glycans. The Stxs screens identified major glycosyltransferases (GTs) and transporters involved in Gb3 biosynthesis, while the ricin screen identified GTs and transporters involved in N-linked ...


The Nf-Kappab Factor Relish Regulates Atg1 Expression And Controls Autophagy, Anubhab Nandy, Lin Lin, Panagiotis D. Velentzas, Louisa P. Wu, Eric H. Baehrecke, Neal S. Silverman Nov 2018

The Nf-Kappab Factor Relish Regulates Atg1 Expression And Controls Autophagy, Anubhab Nandy, Lin Lin, Panagiotis D. Velentzas, Louisa P. Wu, Eric H. Baehrecke, Neal S. Silverman

Open Access Articles

Macroautophagy and cell death both contribute to innate immunity, but little is known about how these processes integrate. Drosophila larval salivary glands require autophagy for developmentally programmed cell death, and innate immune signaling factors increase in these dying cells. Here, we show that the nuclear factor kappaB (NF-kappaB) factor Relish, a component of the immune deficiency (Imd) pathway, is required for salivary gland degradation. Surprisingly, of the classic Imd pathway components, only Relish and the PGRP receptors were involved in salivary gland degradation. Significantly, Relish controls salivary gland degradation by regulating autophagy but not caspases. In addition, expression of either ...


Crispr-Delivery Particles Targeting Nuclear Receptor-Interacting Protein 1 (Nrip1) In Adipose Cells To Enhance Energy Expenditure, Yuefei Shen, Jessica L. Cohen, Sarah M. Nicoloro, Mark Kelly, Batuhan Yenilmez, Felipe Henriques, Emmanouela Tsagkaraki, Yvonne J. K. Edwards, Xiaodi Hu, Randall H. Friedline, Jason K. Kim, Michael P. Czech Nov 2018

Crispr-Delivery Particles Targeting Nuclear Receptor-Interacting Protein 1 (Nrip1) In Adipose Cells To Enhance Energy Expenditure, Yuefei Shen, Jessica L. Cohen, Sarah M. Nicoloro, Mark Kelly, Batuhan Yenilmez, Felipe Henriques, Emmanouela Tsagkaraki, Yvonne J. K. Edwards, Xiaodi Hu, Randall H. Friedline, Jason K. Kim, Michael P. Czech

Open Access Articles

RNA-guided, engineered nucleases derived from the prokaryotic adaptive immune system CRISPR-Cas represent a powerful platform for gene deletion and editing. When used as a therapeutic approach, direct delivery of Cas9 protein and single-guide RNA (sgRNA) could circumvent the safety issues associated with plasmid delivery and therefore represents an attractive tool for precision genome engineering. Gene deletion or editing in adipose tissue to enhance its energy expenditure, fatty acid oxidation, and secretion of bioactive factors through a "browning" process presents a potential therapeutic strategy to alleviate metabolic disease. Here, we developed "CRISPR-delivery particles," denoted CriPs, composed of nano-size complexes of Cas9 ...


Emerging Roles Of The Membrane Potential: Action Beyond The Action Potential, Lina Abdul Kadir, Michael Stacey, Richard Barrett-Jolley Nov 2018

Emerging Roles Of The Membrane Potential: Action Beyond The Action Potential, Lina Abdul Kadir, Michael Stacey, Richard Barrett-Jolley

Bioelectrics Publications

Whilst the phenomenon of an electrical resting membrane potential (RMP) is a central tenet of biology, it is nearly always discussed as a phenomenon that facilitates the propagation of action potentials in excitable tissue, muscle, and nerve. However, as ion channel research shifts beyond these tissues, it became clear that the RMP is a feature of virtually all cells studied. The RMP is maintained by the cell's compliment of ion channels. Transcriptome sequencing is increasingly revealing that equally rich compliments of ion channels exist in both excitable and non-excitable tissue. In this review, we discuss a range of critical ...


Activation Of The Apoptotic Pathway During Prolonged Prometaphase Blocks Daughter Cell Proliferation, Yumi Uetake, Greenfield Sluder Nov 2018

Activation Of The Apoptotic Pathway During Prolonged Prometaphase Blocks Daughter Cell Proliferation, Yumi Uetake, Greenfield Sluder

Radiology Publications

When untransformed human cells spend >1.5 hr. in prometaphase under standard culture conditions, all daughters arrest in G1 despite normal division of their mothers. We investigate what happens during prolonged prometaphase that leads to daughter cell arrest in the absence of DNA damage. We find that progressive loss of anti-apoptotic MCL-1 activity and oxidative stress act in concert to partially activate the apoptosis pathway resulting in the delayed death of some daughters and senescence for the rest. At physiological oxygen levels, longer prometaphase durations are needed for all daughters to arrest. Partial activation of apoptosis during prolonged prometaphase leads ...


Inhibition Of Triggering Receptor Expressed On Myeloid Cells 1 Ameliorates Inflammation And Macrophage And Neutrophil Activation In Alcoholic Liver Disease In Mice, David Tornai, Istvan Furi, Zu T. Shen, Alexander B. Sigalov, Sahin Coban, Gyongyi Szabo Oct 2018

Inhibition Of Triggering Receptor Expressed On Myeloid Cells 1 Ameliorates Inflammation And Macrophage And Neutrophil Activation In Alcoholic Liver Disease In Mice, David Tornai, Istvan Furi, Zu T. Shen, Alexander B. Sigalov, Sahin Coban, Gyongyi Szabo

Open Access Articles

Alcoholic liver disease (ALD) is characterized by macrophage and neutrophil leukocyte recruitment and activation in the liver. Damage- and pathogen-associated molecular patterns contribute to a self-perpetuating proinflammatory state in ALD. Triggering receptor expressed on myeloid cells 1 (TREM-1) is a surface receptor that amplifies inflammation induced by toll-like receptors (TLRs) and is expressed on neutrophils and monocytes/macrophages. We hypothesized that TREM-1 signaling contributes to proinflammatory pathway activation in ALD. Using an in vivo ALD model in mice, we tested the effects of ligand-independent TREM-1 inhibitory peptides that were formulated into human high-density lipoprotein (HDL)-mimicking complexes GF9-HDL and GA ...


Modified Cantilever Arrays Improve Sensitivity And Reproducibility Of Nanomechanical Sensing In Living Cells, Samadhan B. Patil, Rajai M. Al-Jehani, Hashem Etayash, Valerian Turbe, Keren Jiang, Joe Bailey, Walid Al-Akkad, Rania Soudy, Kamaljit Kaur, Rachel A. Mckendry, Thomas Thundat, Joseph W. Ndieyira Oct 2018

Modified Cantilever Arrays Improve Sensitivity And Reproducibility Of Nanomechanical Sensing In Living Cells, Samadhan B. Patil, Rajai M. Al-Jehani, Hashem Etayash, Valerian Turbe, Keren Jiang, Joe Bailey, Walid Al-Akkad, Rania Soudy, Kamaljit Kaur, Rachel A. Mckendry, Thomas Thundat, Joseph W. Ndieyira

Pharmacy Faculty Articles and Research

Mechanical signaling involved in molecular interactions lies at the heart of materials science and biological systems, but the mechanisms involved are poorly understood. Here we use nanomechanical sensors and intact human cells to provide unique insights into the signaling pathways of connectivity networks, which deliver the ability to probe cells to produce biologically relevant, quantifiable and reproducible signals. We quantify the mechanical signals from malignant cancer cells, with 10 cells per ml in 1000-fold excess of non-neoplastic human epithelial cells. Moreover, we demonstrate that a direct link between cells and molecules creates a continuous connectivity which acts like a percolating ...


Identification Of A Novel Anoikis Signalling Pathway Using The Fungal Virulence Factor Gliotoxin, Florian Haun, Simon Neumann, Lukas Peintner, Katrin Wieland, Juri Habicht, Carsten Schwan, Kristine Ostevold, Maria Magdalena Koczorowska, Martin Biniossek, Matthias Kist, Hauke Busch, Melanie Boerries, Roger J. Davis, Ulrich Maurer, Oliver Schilling, Klaus Aktories, Christoph Borner Aug 2018

Identification Of A Novel Anoikis Signalling Pathway Using The Fungal Virulence Factor Gliotoxin, Florian Haun, Simon Neumann, Lukas Peintner, Katrin Wieland, Juri Habicht, Carsten Schwan, Kristine Ostevold, Maria Magdalena Koczorowska, Martin Biniossek, Matthias Kist, Hauke Busch, Melanie Boerries, Roger J. Davis, Ulrich Maurer, Oliver Schilling, Klaus Aktories, Christoph Borner

Open Access Articles

Anoikis is a form of apoptosis induced by cell detachment. Integrin inactivation plays a major role in the process but the exact signalling pathway is ill-defined. Here we identify an anoikis pathway using gliotoxin (GT), a virulence factor of the fungus Aspergillus fumigatus, which causes invasive aspergillosis in humans. GT prevents integrin binding to RGD-containing extracellular matrix components by covalently modifying cysteines in the binding pocket. As a consequence, focal adhesion kinase (FAK) is inhibited resulting in dephosphorylation of p190RhoGAP, allowing activation of RhoA. Sequential activation of ROCK, MKK4/MKK7 and JNK then triggers pro-apoptotic phosphorylation of Bim. Cells in ...


A Population Of Gut Epithelial Enterochromaffin Cells Is Mechanosensitive And Requires Piezo2 To Convert Force Into Serotonin Release, Constanza Alcaino, Kaitlyn R. Knutson, Anthony J. Treichel, Gulcan Yildiz, Peter R. Strege, David R. Linden, Joyce H. Li, Andrew B. Leiter, Joseph H. Szurszewski, Gianrico Farrugia, Arthur Beyder Aug 2018

A Population Of Gut Epithelial Enterochromaffin Cells Is Mechanosensitive And Requires Piezo2 To Convert Force Into Serotonin Release, Constanza Alcaino, Kaitlyn R. Knutson, Anthony J. Treichel, Gulcan Yildiz, Peter R. Strege, David R. Linden, Joyce H. Li, Andrew B. Leiter, Joseph H. Szurszewski, Gianrico Farrugia, Arthur Beyder

Open Access Articles

Enterochromaffin (EC) cells constitute the largest population of intestinal epithelial enteroendocrine (EE) cells. EC cells are proposed to be specialized mechanosensory cells that release serotonin in response to epithelial forces, and thereby regulate intestinal fluid secretion. However, it is unknown whether EE and EC cells are directly mechanosensitive, and if so, what the molecular mechanism of their mechanosensitivity is. Consequently, the role of EE and EC cells in gastrointestinal mechanobiology is unclear. Piezo2 mechanosensitive ion channels are important for some specialized epithelial mechanosensors, and they are expressed in mouse and human EC cells. Here, we use EC and EE cell ...


Are Membranes Non-Apoptotic Compartments For Apoptotic Caspases, Andreas Bergmann Aug 2018

Are Membranes Non-Apoptotic Compartments For Apoptotic Caspases, Andreas Bergmann

Open Access Articles

Critical mediators of apoptotic cell death are caspases, a highly specialized class of Cys-proteases that cleave substrates after Asp residues. Under normal conditions, caspases are cytosolic proteins. After their activation, they cleave a large number of cytosolic proteins and execute apoptosis (Figure 1, left). However, in addition to their well-studied role in apoptosis, caspases also have many non-apoptotic functions [1, 2]. It is not very well understood how cells escape the potential harmful action of caspases when they perform nonapoptotic functions. In our recent work, we now show that epithelial cells may prevent apoptosis by sequestration of caspases at the ...


Jnk Regulates Muscle Remodeling Via Myostatin/Smad Inhibition, Sarah J. Lessard, Tara L. Macdonald, Prerana Pathak, Myoung Souk Han, Vernon G. Coffey, Johann Edge, Donato A. Rivas, Michael F. Hirshman, Roger J. Davis, Laurie J. Goodyear Aug 2018

Jnk Regulates Muscle Remodeling Via Myostatin/Smad Inhibition, Sarah J. Lessard, Tara L. Macdonald, Prerana Pathak, Myoung Souk Han, Vernon G. Coffey, Johann Edge, Donato A. Rivas, Michael F. Hirshman, Roger J. Davis, Laurie J. Goodyear

Open Access Articles

Skeletal muscle has a remarkable plasticity to adapt and remodel in response to environmental cues, such as physical exercise. Endurance exercise stimulates improvements in muscle oxidative capacity, while resistance exercise induces muscle growth. Here we show that the c-Jun N-terminal kinase (JNK) is a molecular switch that when active, stimulates muscle fibers to grow, resulting in increased muscle mass. Conversely, when muscle JNK activation is suppressed, an alternative remodeling program is initiated, resulting in smaller, more oxidative muscle fibers, and enhanced aerobic fitness. When muscle is exposed to mechanical stress, JNK initiates muscle growth via phosphorylation of the transcription factor ...


Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees Aug 2018

Effect Of Morinda Citrifolia (Noni)-Enriched Diet On Hepatic Heat Shock Protein And Lipid Metabolism-Related Genes In Heat Stressed Broiler Chickens, Joshua Flees

Theses and Dissertations

Heat stress (HS) has been reported to alter fat deposition in broilers, however the underlying molecular mechanisms are not well-defined; therefore, the objectives of the current study were to: (1) determine the effects of acute (2 h) and chronic (3 wk) HS on the expression of key molecular signatures involved in hepatic lipogenic and lipolytic programs; and (2) assess if diet supplementation with dried Noni medicinal plant (0.2% of the diet) modulates these effects. Broilers (n=480 males, 1 d) were randomly assigned to 12 environmental chambers, subjected to two environmental conditions (HS at 35°C vs. thermoneutral condition ...


Llc Tumor Cells-Derivated Factors Reduces Adipogenesis In Co-Culture System, Magno Alves Lopes, Felipe Oliveira Franco, Felipe Henriques, Sidney Barnabe Peres, Miguel Luiz Batista Jr. Jul 2018

Llc Tumor Cells-Derivated Factors Reduces Adipogenesis In Co-Culture System, Magno Alves Lopes, Felipe Oliveira Franco, Felipe Henriques, Sidney Barnabe Peres, Miguel Luiz Batista Jr.

Open Access Articles

Cancer cachexia (CC) is a multifactorial syndrome with an unknown etiology. The primary symptom is the progressive reduction of the body weight. Recently, down-regulation of adipogenic and lipogenic genes were demonstrated to be early affected during cachexia progression in adipose tissue (AT), resulting in AT remodeling. Thus, this study aimed to evaluate in a co-culture system the influence of the Lewis Lung Carcinoma (LLC) tumor cells (c/c-LLC) in an established pre-adipocyte cell line 3T3-L1 adipogenic capacity. c/c-LLC in the presence of 3T3-L1 caused a reduction in lipids accumulation, suggesting that secretory tumor cells products may affect adipogenesis. Interestingly ...


Effects Of Fatty Acids From Avocados On Expression Of The Hmg1 Gene In Tetrahymena Thermophila, Jasmine Phan, Connor Kane, Stefanie Otto-Hitt Jul 2018

Effects Of Fatty Acids From Avocados On Expression Of The Hmg1 Gene In Tetrahymena Thermophila, Jasmine Phan, Connor Kane, Stefanie Otto-Hitt

Life and Environmental Sciences Course-based Research Projects

The enzyme 3-Hydroxy-3-Methyl-Glutaryl-CoA Reductase (HMG) HMG catalyzes the ratelimiting step in the biosynthesis of cholesterol and is a common drug target for cholesterol reduction. Previous studies in rats have shown that avocado oil reduces cholesterol levels. We were interested in determining whether the healthy fatty acids in avocado oil would have an effect on the expression of HMG. In this study, Tetrahymena thermophila were treated with avocado oil to determine the effect of fatty acids on expression of the HMG1 gene that encodes HMG. Expression of HMG1 was monitored using reverse transcription and semi-quantitative PCR. We predicted that expression of ...


Effect Of Alcohol On Pfk1 Gene Expression And Feeding Activity In Tetrahymena Thermophila, Evelyn Sowers, Alex Skoulis, Stefanie Otto-Hitt Jul 2018

Effect Of Alcohol On Pfk1 Gene Expression And Feeding Activity In Tetrahymena Thermophila, Evelyn Sowers, Alex Skoulis, Stefanie Otto-Hitt

Life and Environmental Sciences Course-based Research Projects

The purpose of this experiment was to test whether alcohol induces starvation conditions in Tetrahymena thermophila. For this experiment, it was hypothesized that alcohol induces starvation due to a lack of energy available in the organism for feeding. This hypothesis was tested by monitoring food vacuole formation and expression of the PFK1 gene in Tetrahymena that were exposed to alcohol. The PFK-1 gene was chosen because its encoded protein plays an essential role in cellular metabolism. For the experiment, control and experimental cultures of Tetrahymena themophila were maintained in a nutrient rich media, with the media of the experimental group ...


Analysis Of Fbp1 Gene Expression In Uv Light-Exposed Tetrahymena Thermophila Cultures, Colby Henry, Stefanie Otto-Hitt Jul 2018

Analysis Of Fbp1 Gene Expression In Uv Light-Exposed Tetrahymena Thermophila Cultures, Colby Henry, Stefanie Otto-Hitt

Life and Environmental Sciences Course-based Research Projects

In this study, Tetrahymena thermophila cultures were exposed to an acute treatment of UV light and expression of the FBP1 gene was examined. The FBP1 gene encodes Fructose- 1,6-biphosphatase which plays an important role in the process of gluconeogenesis. It was hypothesized that exposure of Tetrahymena to UV light would cause an upregulation in DNA repair enzymes, thereby causing these cells to require higher levels of glucose. The higher demand for glucose would then result in the upregulation of gluconeogenesis and FBP1. Following acute exposure of Tetrahymena cultures to UV light, the expression of FBP1 was analyzed using reverse ...


Analyzing Atp Synthetase F1 Expression In Heat-Exposed Tetrahymena Thermophila, Kevin Gardner, Ian Lorang, Stefanie Otto-Hitt Jul 2018

Analyzing Atp Synthetase F1 Expression In Heat-Exposed Tetrahymena Thermophila, Kevin Gardner, Ian Lorang, Stefanie Otto-Hitt

Life and Environmental Sciences Course-based Research Projects

In this study, we investigated the effect of temperature on expression of the ATP1 gene in the organism Tetrahymena thermophila. We hypothesized that expression of the ATP1 gene would increase as we increased temperature. ATP1 is a highly conserved gene in Tetrahymena that codes for the alpha subunit of ATP Synthase, an enzyme that generates the energy molecule ATP. We decided to use heat treatment based on studies performed on ATP1 in Alaskan Cod showing increased expression in response to increased temperatures (Michael et al., 2015). We used reverse transcription and semi-quantitative PCR to analyze expression of ATP1 in our ...


Role Of The Mapk/Cjun Nh2-Terminal Kinase Signaling Pathway In Starvation-Induced Autophagy, Seda Barutcu, Nomeda Girnius, Santiago Vernia, Roger J. Davis Jun 2018

Role Of The Mapk/Cjun Nh2-Terminal Kinase Signaling Pathway In Starvation-Induced Autophagy, Seda Barutcu, Nomeda Girnius, Santiago Vernia, Roger J. Davis

Davis Lab Publications

Autophagy is required for cellular homeostasis and can determine cell viability in response to stress. It is established that MTOR is a master regulator of starvation-induced macroautophagy/autophagy, but recent studies have also implicated an essential role for the MAPK8/cJun NH2-terminal kinase 1 signal transduction pathway. We found that MAPK8/JNK1 and MAPK9/JNK2 were not required for autophagy caused by starvation or MTOR inhibition in murine fibroblasts and epithelial cells. These data demonstrate that MAPK8/9 has no required role in starvation-induced autophagy. We conclude that the role of MAPK8/9 in autophagy may be context-dependent and more ...


Rna Polymerase Ii Transcription Attenuation At The Yeast Dna Repair Gene, Def1, Involves Sen1-Dependent And Polyadenylation Site-Dependent Termination, Courtney Whalen, Christine Tuohy, Thomas Tallo, James W. Kaufman, Claire Moore, Jason N. Kuehner May 2018

Rna Polymerase Ii Transcription Attenuation At The Yeast Dna Repair Gene, Def1, Involves Sen1-Dependent And Polyadenylation Site-Dependent Termination, Courtney Whalen, Christine Tuohy, Thomas Tallo, James W. Kaufman, Claire Moore, Jason N. Kuehner

Open Access Articles

Termination of RNA Polymerase II (Pol II) activity serves a vital cellular role by separating ubiquitous transcription units and influencing RNA fate and function. In the yeast Saccharomyces cerevisiae, Pol II termination is carried out by cleavage and polyadenylation factor (CPF-CF) and Nrd1-Nab3-Sen1 (NNS) complexes, which operate primarily at mRNA and non-coding RNA genes, respectively. Premature Pol II termination (attenuation) contributes to gene regulation, but there is limited knowledge of its prevalence and biological significance. In particular, it is unclear how much crosstalk occurs between CPF-CF and NNS complexes and how Pol II attenuation is modulated during stress adaptation. In ...


Syndromic Congenital Myelofibrosis Associated With A Loss-Of-Function Variant In Rbsn, Pilar L. Magoulas, Silvia Corvera, Luis M. Franco May 2018

Syndromic Congenital Myelofibrosis Associated With A Loss-Of-Function Variant In Rbsn, Pilar L. Magoulas, Silvia Corvera, Luis M. Franco

University of Massachusetts Medical School Faculty Publications

The human proteins rabenosyn-5 and VPS45 form a complex that plays a key role in early endocytosis. Pathogenic variants in VPS45 cause severe congenital neutropenia (SCN) with impaired neutrophil function, reticulin fibrosis of the bone marrow, and extramedullary hematopoiesis (OMIM: 615285). Patients with a specific VPS45 variant (p.Glu238Lys) also have intellectual disability and bilateral optic nerve hypoplasia. To date, the only evidence of a potential role for RBSN in human disease is the report of a homozygous missense variant (p.Gly425Arg) in a patient with intellectual disability, seizures, microcephaly, osteopenia, mild reticulin fibrosis of the bone marrow, and transient ...


Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech May 2018

Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech

University of Massachusetts Medical School Faculty Publications

White adipose tissue (WAT) secretes factors to communicate with other metabolic organs to maintain energy homeostasis. We previously reported that perturbation of adipocyte de novo lipogenesis (DNL) by deletion of fatty acid synthase (FASN) causes expansion of sympathetic neurons within white adipose tissue (WAT) and the appearance of beige adipocytes. Here we report evidence that white adipocyte DNL activity is also coupled to neuronal regulation and thermogenesis in brown adipose tissue (BAT). Induced deletion of FASN in all adipocytes in mature mice (iAdFASNKO) enhanced sympathetic innervation and neuronal activity as well as UCP1 expression in both WAT and BAT. In ...


A Microtubule-Dynein Tethering Complex Regulates The Axonemal Inner Dynein F (I1), Tomohiro Kubo, Yuqing Hou, Deborah A. Cochran, George B. Witman, Toshiyuki Oda May 2018

A Microtubule-Dynein Tethering Complex Regulates The Axonemal Inner Dynein F (I1), Tomohiro Kubo, Yuqing Hou, Deborah A. Cochran, George B. Witman, Toshiyuki Oda

Radiology Publications

Motility of cilia/flagella is generated by a coordinated activity of thousands of dyneins. Inner dynein arms (IDAs) are particularly important for the formation of ciliary/flagellar waveforms, but the molecular mechanism of IDA regulation is poorly understood. Here, we show using cryo-electron tomography and biochemical analyses of Chlamydomonas flagella that a conserved protein FAP44 forms a complex that tethers IDA f (I1 dynein) head domains to the A-tubule of the axonemal outer doublet microtubule. In wild-type flagella, IDA f showed little nucleotide-dependent movement except for a tilt in the fbeta head perpendicular to the microtubule-sliding direction. In the absence ...


Deconvolution Of Subcellular Protrusion Heterogeneity And The Underlying Actin Regulator Dynamics From Live Cell Imaging, Chuangqi Wang, Hee June Choi, Sung-Jin Kim, Aesha Desai, Namgyu Lee, Dohoon Kim, Yongho Bae, Kwonmoo Lee Apr 2018

Deconvolution Of Subcellular Protrusion Heterogeneity And The Underlying Actin Regulator Dynamics From Live Cell Imaging, Chuangqi Wang, Hee June Choi, Sung-Jin Kim, Aesha Desai, Namgyu Lee, Dohoon Kim, Yongho Bae, Kwonmoo Lee

Open Access Articles

Cell protrusion is morphodynamically heterogeneous at the subcellular level. However, the mechanism of cell protrusion has been understood based on the ensemble average of actin regulator dynamics. Here, we establish a computational framework called HACKS (deconvolution of heterogeneous activity in coordination of cytoskeleton at the subcellular level) to deconvolve the subcellular heterogeneity of lamellipodial protrusion from live cell imaging. HACKS identifies distinct subcellular protrusion phenotypes based on machine-learning algorithms and reveals their underlying actin regulator dynamics at the leading edge. Using our method, we discover "accelerating protrusion", which is driven by the temporally ordered coordination of Arp2/3 and VASP ...


Reconstitution Of Gabaergic Postsynapses In Host Cells, Karthik Kanamalla Apr 2018

Reconstitution Of Gabaergic Postsynapses In Host Cells, Karthik Kanamalla

Honors Scholar Theses

Type A GABA receptors (GABAARs) can be found embedded in postsynaptic membranes or in a variety of extrasynaptic locations. Receptors with synaptic function are recruited to the postsynapse by submembranous scaffolds composed of gephyrin and collybistin (CB). This study was aimed at assessing whether the ability to interact with the scaffold differentiates synaptic from non-synaptic receptors. Using HEK293 cells as an expression system, and indirect immunofluorescence (IF), co-localization of extrasynaptic receptors α1β3δ and α4β3δ with the CB-gephyrin scaffold was assessed and compared with that of the synaptic receptor α1β3γ2. Results indicated that both extrasynaptic receptors were able to colocalize with ...


Cystic Fibrosis-Related Diabetes Is Caused By Islet Loss And Inflammation, Nathaniel J. Hart, Jenny Aurielle B. Babon, Megan E. Denicola, Sally C. Kent, Alvin C. Powers Apr 2018

Cystic Fibrosis-Related Diabetes Is Caused By Islet Loss And Inflammation, Nathaniel J. Hart, Jenny Aurielle B. Babon, Megan E. Denicola, Sally C. Kent, Alvin C. Powers

Open Access Articles

Cystic fibrosis-related (CF-related) diabetes (CFRD) is an increasingly common and devastating comorbidity of CF, affecting approximately 35% of adults with CF. However, the underlying causes of CFRD are unclear. Here, we examined cystic fibrosis transmembrane conductance regulator (CFTR) islet expression and whether the CFTR participates in islet endocrine cell function using murine models of beta cell CFTR deletion and normal and CF human pancreas and islets. Specific deletion of CFTR from murine beta cells did not affect beta cell function. In human islets, CFTR mRNA was minimally expressed, and CFTR protein and electrical activity were not detected. Isolated CF/CFRD ...


Jip1-Mediated Jnk Activation Negatively Regulates Synaptic Plasticity And Spatial Memory, Caroline Morel, Tessi Sherrin, Norman J. Kennedy, Kelly H. Forest, Seda Barutcu, Michael Robles, Ezekiel Carpenter-Hyland, Naghum Alfulaij, Claire L. Standen, Robert A. Nichols, Morris Benveniste, Roger J. Davis, Cedomir Todorovic Apr 2018

Jip1-Mediated Jnk Activation Negatively Regulates Synaptic Plasticity And Spatial Memory, Caroline Morel, Tessi Sherrin, Norman J. Kennedy, Kelly H. Forest, Seda Barutcu, Michael Robles, Ezekiel Carpenter-Hyland, Naghum Alfulaij, Claire L. Standen, Robert A. Nichols, Morris Benveniste, Roger J. Davis, Cedomir Todorovic

University of Massachusetts Medical School Faculty Publications

The c-Jun N-terminal kinase (JNK) signal transduction pathway is implicated in learning and memory. Here, we examined the role of JNK activation mediated by the JIP1 scaffold protein. We compared male wild-type mice with a mouse model harboring a point mutation in the Jip1 gene that selectively blocks JIP1-mediated JNK activation. These male mutant mice exhibited increased NMDA receptor currents, increased NMDA receptor-mediated gene expression, and a lower threshold for induction of hippocampal long-term potentiation. The JIP1 mutant mice also displayed improved hippocampus-dependent spatial memory and enhanced associative fear conditioning. These results were confirmed using a second JIP1 mutant mouse ...


Multiple Molecular Mechanisms Rescue Mtdna Disease In C. Elegans, Suraiya Haroon, Annie Li, Jaye L. Weinert, Clark Fritsch, Nolan G. Ericson, Jasmine Alexander-Floyd, Bart P. Braeckman, Cole M. Haynes, Jason H. Bielas, Tali Gidalevitz, Marc Vermulst Mar 2018

Multiple Molecular Mechanisms Rescue Mtdna Disease In C. Elegans, Suraiya Haroon, Annie Li, Jaye L. Weinert, Clark Fritsch, Nolan G. Ericson, Jasmine Alexander-Floyd, Bart P. Braeckman, Cole M. Haynes, Jason H. Bielas, Tali Gidalevitz, Marc Vermulst

University of Massachusetts Medical School Faculty Publications

Genetic instability of the mitochondrial genome (mtDNA) plays an important role in human aging and disease. Thus far, it has proven difficult to develop successful treatment strategies for diseases that are caused by mtDNA instability. To address this issue, we developed a model of mtDNA disease in the nematode C. elegans, an animal model that can rapidly be screened for genes and biological pathways that reduce mitochondrial pathology. These worms recapitulate all the major hallmarks of mtDNA disease in humans, including increased mtDNA instability, loss of respiration, reduced neuromuscular function, and a shortened lifespan. We found that these phenotypes could ...


Cbx4 Sumoylates Prdm16 To Regulate Adipose Tissue Thermogenesis, Qingbo Chen, Lei Huang, Dongning Pan, Lihua (Julie) Zhu, Yong-Xu Wang Mar 2018

Cbx4 Sumoylates Prdm16 To Regulate Adipose Tissue Thermogenesis, Qingbo Chen, Lei Huang, Dongning Pan, Lihua (Julie) Zhu, Yong-Xu Wang

Open Access Articles

Transcriptional co-activator Prdm16 controls brown fat development and white fat browning, but how this thermogenic function is modulated post-translationally is poorly understood. Here, we report that Cbx4, a Polycomb group protein, is a SUMO E3 ligase for Prdm16 and that Cbx4-mediated sumoylation of Prdm16 is required for thermogenic gene expression. Cbx4 expression is enriched in brown fat and is induced in adipose tissue by acute cold exposure. Sumoylation of Prdm16 at lysine 917 by Cbx4 blocks its ubiquitination-mediated degradation, thereby augmenting its stability and thermogenic function. Moreover, this sumoylation event primes Prdm16 to be further stabilized by methyltransferase Ehmt1. Heterozygous ...


Alpha Cell Function And Gene Expression Are Compromised In Type 1 Diabetes, Marcela Brissova, David Blodgett, Dale L. Greiner, David M. Harlan, Alvin C. Powers Mar 2018

Alpha Cell Function And Gene Expression Are Compromised In Type 1 Diabetes, Marcela Brissova, David Blodgett, Dale L. Greiner, David M. Harlan, Alvin C. Powers

Open Access Articles

Many patients with type 1 diabetes (T1D) have residual beta cells producing small amounts of C-peptide long after disease onset but develop an inadequate glucagon response to hypoglycemia following T1D diagnosis. The features of these residual beta cells and alpha cells in the islet endocrine compartment are largely unknown, due to the difficulty of comprehensive investigation. By studying the T1D pancreas and isolated islets, we show that remnant beta cells appeared to maintain several aspects of regulated insulin secretion. However, the function of T1D alpha cells was markedly reduced, and these cells had alterations in transcription factors constituting alpha and ...


Molecular Mechanisms Of Cell Death: Recommendations Of The Nomenclature Committee On Cell Death 2018, Lorenzo Galluzzi, Eric H. Baehrecke, Francis Ka-Ming Chan, Guido Kroemer Mar 2018

Molecular Mechanisms Of Cell Death: Recommendations Of The Nomenclature Committee On Cell Death 2018, Lorenzo Galluzzi, Eric H. Baehrecke, Francis Ka-Ming Chan, Guido Kroemer

Open Access Articles

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell ...