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Full-Text Articles in Life Sciences

A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima Sep 2019

A Critical Role Of Vmp1 In Lipoprotein Secretion, Hideaki Morishita, Yan G. Zhao, Norito Tamura, Taki Nishimura, Yuki Kanda, Yuriko Sakamaki, Mitsuyo Okazaki, Dongfang Li, Noboru Mizushima

Open Access Articles

Lipoproteins are lipid-protein complexes that are primarily generated and secreted from the intestine, liver, and visceral endoderm and delivered to peripheral tissues. Lipoproteins, which are assembled in the endoplasmic reticulum (ER) membrane, are released into the ER lumen for secretion, but its mechanism remains largely unknown. Here, we show that the release of lipoproteins from the ER membrane requires VMP1, an ER transmembrane protein essential for autophagy and certain types of secretion. Loss of vmp1, but not other autophagy-related genes, in zebrafish causes lipoprotein accumulation in the intestine and liver. Vmp1 deficiency in mice also leads to lipid accumulation in ...


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 ...


The Cjun Nh2-Terminal Kinase (Jnk) Signaling Pathway Promotes Genome Stability And Prevents Tumor Initiation, Nomeda A. Girnius, Yvonne J. K. Edwards, David S. Garlick, Roger J. Davis Jun 2018

The Cjun Nh2-Terminal Kinase (Jnk) Signaling Pathway Promotes Genome Stability And Prevents Tumor Initiation, Nomeda A. Girnius, Yvonne J. K. Edwards, David S. Garlick, Roger J. Davis

University of Massachusetts Medical School Faculty Publications

Breast cancer is the most commonly diagnosed malignancy in women. Analysis of breast cancer genomic DNA indicates frequent loss-of-function mutations in components of the cJUN NH2-terminal kinase (JNK) signaling pathway. Since JNK signaling can promote cell proliferation by activating the AP1 transcription factor, this apparent association of reduced JNK signaling with tumor development was unexpected. We examined the effect of JNK deficiency in the murine breast epithelium. Loss of JNK signaling caused genomic instability and the development of breast cancer. Moreover, JNK deficiency caused widespread early neoplasia and rapid tumor formation in a murine model of breast cancer. This tumor ...


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 ...


Crispr-Based Dna Imaging In Living Cells Reveals Cell Cycle-Dependent Chromosome Dynamics, Hanhui Ma, Li-Chun Tu, University Of Central Florida, Yu-Chieh Chung, David Grünwald, Shaojie Zhang, Thoru Pederson Sep 2017

Crispr-Based Dna Imaging In Living Cells Reveals Cell Cycle-Dependent Chromosome Dynamics, Hanhui Ma, Li-Chun Tu, University Of Central Florida, Yu-Chieh Chung, David Grünwald, Shaojie Zhang, Thoru Pederson

University of Massachusetts Medical School Faculty Publications

In contrast to the well-studied condensation and folding of chromosomes during mitosis, their dynamics in interphase are less understood. We developed a sensitive, multicolor system, CRISPR-Sirius, allowing the real-time tracking of the dynamics of chromosomal loci. We tracked loci kilobases to megabases apart and found significant variation in the inter-locus distances of each pair, indicating differing degrees of DNA contortion. We resolved two distinct modes of dynamics of loci: saltatory local movements as well as translational movements of the domain. The magnitude of both of these modes of movements increased from early to late G1, whereas the translational movements were ...


Glycolytic Reliance Promotes Anabolism In Photoreceptors, Yashodhan Chinchore, Tedi Begaj, David Wu, Eugene Drokhlyansky, Constance L. Cepko Jun 2017

Glycolytic Reliance Promotes Anabolism In Photoreceptors, Yashodhan Chinchore, Tedi Begaj, David Wu, Eugene Drokhlyansky, Constance L. Cepko

Senior Scholars Program

Vertebrate photoreceptors are among the most metabolically active cells, exhibiting a high rate of ATP consumption. This is coupled with a high anabolic demand, necessitated by the diurnal turnover of a specialized membrane-rich organelle, the outer segment, which is the primary site of phototransduction. How photoreceptors balance their catabolic and anabolic demands is poorly understood. Here, we show that rod photoreceptors in mice rely on glycolysis for their outer segment biogenesis. Genetic perturbations targeting allostery or key regulatory nodes in the glycolytic pathway impacted the size of the outer segments. Fibroblast growth factor signaling was found to regulate glycolysis, with ...


Ift Trains In Different Stages Of Assembly Queue At The Ciliary Base For Consecutive Release Into The Cilium, Jason M. Brown, Tyler Picariello, Deborah A. Cochran, George B. Witman, Karl Lechtreck May 2017

Ift Trains In Different Stages Of Assembly Queue At The Ciliary Base For Consecutive Release Into The Cilium, Jason M. Brown, Tyler Picariello, Deborah A. Cochran, George B. Witman, Karl Lechtreck

Radiology Publications and Presentations

Intraflagellar transport (IFT) trains, multimegadalton assemblies of IFT proteins and motors, traffic proteins in cilia. To study how trains assemble, we employed fluorescence protein-tagged IFT proteins in Chlamydomonas reinhardtii. IFT-A and motor proteins are recruited from the cell body to the basal body pool, assembled into trains, move through the cilium, and disperse back into the cell body. In contrast to this 'open' system, IFT-B proteins from retrograde trains reenter the pool and a portion is reused directly in anterograde trains indicating a 'semi-open' system. Similar IFT systems were also observed in Tetrahymena thermophila and IMCD3 cells. FRAP analysis indicated ...


Size-Dependent Expression Of The Mitotic Activator Cdc25 As A Mechanism Of Size Control In Fission Yeast, Daniel L. Keifenheim, Xi-Ming Sun, Edridge D'Souza, Makoto J. Ohira, Mira Magner, Lawrence Livermore National Laboratory, Samuel Marguerat, Nicholas R. Rhind Feb 2017

Size-Dependent Expression Of The Mitotic Activator Cdc25 As A Mechanism Of Size Control In Fission Yeast, Daniel L. Keifenheim, Xi-Ming Sun, Edridge D'Souza, Makoto J. Ohira, Mira Magner, Lawrence Livermore National Laboratory, Samuel Marguerat, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

Proper cell size is essential for cellular function (Hall et al., 2004). Nonetheless, despite more than 100 years of work on the subject, the mechanisms that maintain cell size homeostasis are largely mysterious (Marshall et al., 2012). Cells in growing populations maintain cell size within a narrow range by coordinating growth and division. Bacterial and eukaryotic cells both demonstrate homeostatic size control, which maintains population-level variation in cell size within a certain range, and returns the population average to that range if it is perturbed (Marshall et al., 2012; Turner et al., 2012; Amodeo and Skotheim, 2015). Recent work has ...


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 ...


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 ...


No Current Evidence For Widespread Dosage Compensation In S. Cerevisiae, Eduardo M. Torres, Michael Springer, Angelika Amon Mar 2016

No Current Evidence For Widespread Dosage Compensation In S. Cerevisiae, Eduardo M. Torres, Michael Springer, Angelika Amon

UMass Metabolic Network Publications

Previous studies of laboratory strains of budding yeast had shown that when gene copy number is altered experimentally, RNA levels generally scale accordingly. This is true when the copy number of individual genes or entire chromosomes is altered. In a recent study, Hose et al. (2015) reported that this tight correlation between gene copy number and RNA levels is not observed in recently isolated wild Saccharomyces cerevisiae variants. To understand the origins of this proposed difference in gene expression regulation between natural variants and laboratory strains of S. cerevisiae, we evaluated the karyotype and gene expression studies performed by Hose ...


Excitatory Transmission Onto Agrp Neurons Is Regulated By Cjun Nh2-Terminal Kinase 3 In Response To Metabolic Stress, Santiago Vernia, Caroline Morel, Joseph C. Madara, Julie Cavanagh-Kyros, Tamera Barrett, Kathryn O. Chase, Norman J. Kennedy, Dae Young Jung, Jason K. Kim, Neil Aronin, Richard A. Flavell, Bradford B. Lowell, Roger J. Davis Feb 2016

Excitatory Transmission Onto Agrp Neurons Is Regulated By Cjun Nh2-Terminal Kinase 3 In Response To Metabolic Stress, Santiago Vernia, Caroline Morel, Joseph C. Madara, Julie Cavanagh-Kyros, Tamera Barrett, Kathryn O. Chase, Norman J. Kennedy, Dae Young Jung, Jason K. Kim, Neil Aronin, Richard A. Flavell, Bradford B. Lowell, Roger J. Davis

Davis Lab Publications

The cJun NH2-terminal kinase (JNK) signaling pathway is implicated in the response to metabolic stress. Indeed, it is established that the ubiquitously expressed JNK1 and JNK2 isoforms regulate energy expenditure and insulin resistance. However, the role of the neuron-specific isoform JNK3 is unclear. Here we demonstrate that JNK3 deficiency causes hyperphagia selectively in high fat diet (HFD)-fed mice. JNK3 deficiency in neurons that express the leptin receptor LEPRb was sufficient to cause HFD-dependent hyperphagia. Studies of sub-groups of leptin-responsive neurons demonstrated that JNK3 deficiency in AgRP neurons, but not POMC neurons, was sufficient to cause the hyperphagic response. These ...