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

Cell Biology Commons

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

Articles 1 - 12 of 12

Full-Text Articles in Cell 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 ...


Rlim-Dependent And -Independent Pathways For X Chromosome Inactivation In Female Escs, Feng Wang, Kurtis N. Mccannell, Ana Boskovic, Xiaochun Zhu, Jongdae Shin, Jun Yu, Judith Gallant, Meg Byron, Jeanne B. Lawrence, Lihua Julie Zhu, Stephen N. Jones, Oliver J. Rando, Thomas G. Fazzio, Ingolf Bach Dec 2017

Rlim-Dependent And -Independent Pathways For X Chromosome Inactivation In Female Escs, Feng Wang, Kurtis N. Mccannell, Ana Boskovic, Xiaochun Zhu, Jongdae Shin, Jun Yu, Judith Gallant, Meg Byron, Jeanne B. Lawrence, Lihua Julie Zhu, Stephen N. Jones, Oliver J. Rando, Thomas G. Fazzio, Ingolf Bach

University of Massachusetts Medical School Faculty Publications

During female mouse embryogenesis, two forms of X chromosome inactivation (XCI) ensure dosage compensation from sex chromosomes. Beginning at the four-cell stage, imprinted XCI (iXCI) exclusively silences the paternal X (Xp), and this pattern is maintained in extraembryonic cell types. Epiblast cells, which give rise to the embryo proper, reactivate the Xp (XCR) and undergo a random form of XCI (rXCI) around implantation. Both iXCI and rXCI depend on the long non-coding RNA Xist. The ubiquitin ligase RLIM is required for iXCI in vivo and occupies a central role in current models of rXCI. Here, we demonstrate the existence of ...


The Fission Yeast S-Phase Cyclin Cig2 Can Drive Mitosis, Mira Magner, Daniel L. Keifenheim, Nicholas R. Rhind Nov 2017

The Fission Yeast S-Phase Cyclin Cig2 Can Drive Mitosis, Mira Magner, Daniel L. Keifenheim, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

Commitment to mitosis is regulated by cyclin-dependent kinase (CDK) activity. In the fission yeast Schizosaccharomyces pombe, the major B-type cyclin, Cdc13, is necessary and sufficient to drive mitotic entry. Furthermore, Cdc13 is also sufficient to drive S phase, demonstrating that a single cyclin can regulate alternating rounds of replication and mitosis and providing the foundation of the quantitative model of CDK function. It has been assumed that Cig2, a B-type cyclin expressed only during S-phase and incapable of driving mitosis in wild-type cells, was specialized for S-phase regulation. Here, we show that Cig2 is capable of driving mitosis. Cig2/CDK ...


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 ...


Rapid Isolation Of Functionally Intact Nuclei From The Yeast Saccharomyces, Mario Niepel, Julia Farr, Michael P. Rout, Caterina Strambio-De-Castilla Jul 2017

Rapid Isolation Of Functionally Intact Nuclei From The Yeast Saccharomyces, Mario Niepel, Julia Farr, Michael P. Rout, Caterina Strambio-De-Castilla

University of Massachusetts Medical School Faculty Publications

Most available methods for nuclear isolation entail lengthy procedures that are difficult to master and generally emphasize yield and enrichment over nuclear preservation, thus limiting their utility for further studies. Here we demonstrate a novel and robust method to rapidly isolate well-preserved yeast nuclei. The method can be easily adapted to multiple preparation scales depending on experimental need and it can readily be performed on multiple samples by a single researcher in one day. We show that the nuclei fraction is strongly enriched and that the resulting nuclei are free from contaminating endoplasmic reticulum and other cell debris. EM studies ...


Single-Molecule Fish In Drosophila Muscle Reveals Location Dependent Mrna Composition Of Megarnps, Akiko Noma, Carlas Smith, Maximiliaan Huisman, Robert M. Martin, Melissa J. Moore, David Grünwald Jun 2017

Single-Molecule Fish In Drosophila Muscle Reveals Location Dependent Mrna Composition Of Megarnps, Akiko Noma, Carlas Smith, Maximiliaan Huisman, Robert M. Martin, Melissa J. Moore, David Grünwald

University of Massachusetts Medical School Faculty Publications

Single-molecule fluorescence in-situ hybridization (smFISH) provides direct access to the spatial relationship between nucleic acids and specific subcellular locations. The ability to precisely localize a messenger RNA can reveal key information about its regulation. Although smFISH is well established in cell culture or thin sections, methods for its accurate application to tissues are lacking. The utility of smFISH in thick tissue sections must overcome several challenges, including probe penetration of fixed tissue, accessibility of target mRNAs for probe hybridization, high fluorescent background, spherical aberration along the optical axis, and image segmentation of organelles. Here we describe how we overcame these ...


Super-Resolution Microscopy Reveals That Disruption Of Ciliary Transition Zone Architecture Is A Cause Of Joubert Syndrome, Xiaoyu Shi, Galo Garcia Iii, Julie C. Van De Weghe, University Of California, San Francisco, Gregory J. Pazour, Dan Doherty, Bo Huang, Jeremy F. Reiter May 2017

Super-Resolution Microscopy Reveals That Disruption Of Ciliary Transition Zone Architecture Is A Cause Of Joubert Syndrome, Xiaoyu Shi, Galo Garcia Iii, Julie C. Van De Weghe, University Of California, San Francisco, Gregory J. Pazour, Dan Doherty, Bo Huang, Jeremy F. Reiter

University of Massachusetts Medical School Faculty Publications

Diverse human ciliopathies, including nephronophthisis (NPHP), Meckel syndrome (MKS) and Joubert syndrome (JBTS), can be caused by mutations affecting components of the transition zone, a ciliary domain near its base. The transition zone controls the protein composition of the ciliary membrane, but how it does so is unclear. To better understand the transition zone and its connection to ciliopathies, we defined the arrangement of key proteins in the transition zone using two-color stochastic optical reconstruction microscopy (STORM). This mapping revealed that NPHP and MKS complex components form nested rings comprised of nine-fold doublets. The NPHP complex component RPGRIP1L forms a ...


Ki-67 Contributes To Normal Cell Cycle Progression And Inactive X Heterochromatin In P21 Checkpoint-Proficient Human Cells, Xiaoming Sun, Aizhan Bizhanova, Timothy D. Matheson, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman May 2017

Ki-67 Contributes To Normal Cell Cycle Progression And Inactive X Heterochromatin In P21 Checkpoint-Proficient Human Cells, Xiaoming Sun, Aizhan Bizhanova, Timothy D. Matheson, Jun Yu, Lihua Julie Zhu, Paul D. Kaufman

University of Massachusetts Medical School Faculty Publications

Ki-67 protein is widely used as a tumor proliferation marker. However, whether Ki-67 affects cell cycle progression has been controversial. Here, we demonstrate that depletion of Ki-67 in human hTERT-RPE1, WI-38, IMR90, hTERT-BJ cell lines and primary fibroblast cells slowed entry into S phase and coordinately downregulated genes related to DNA replication. Some gene expression changes were partially relieved in Ki-67-depleted hTERT-RPE1 cells by co-depletion of the Rb checkpoint protein, but more thorough suppression of the transcriptional and cell cycle defects was observed upon depletion of cell cycle inhibitor p21. Notably, induction of p21 upon depletion of Ki-67 was a ...


Alcohol-Related Changes In The Intestinal Microbiome Influence Neutrophil Infiltration, Inflammation And Steatosis In Early Alcoholic Hepatitis In Mice, Patrick Lowe, Benedek Gyongyosi, Abhishek Satishchandran, Arvin Iracheta-Vellve, Aditya Ambade, Karen Kodys, Donna Catalano, Doyle V. Ward, Gyongyi Szabo Mar 2017

Alcohol-Related Changes In The Intestinal Microbiome Influence Neutrophil Infiltration, Inflammation And Steatosis In Early Alcoholic Hepatitis In Mice, Patrick Lowe, Benedek Gyongyosi, Abhishek Satishchandran, Arvin Iracheta-Vellve, Aditya Ambade, Karen Kodys, Donna Catalano, Doyle V. Ward, Gyongyi Szabo

University of Massachusetts Medical School Faculty Publications

BACKGROUND: Alcohol-induced intestinal dysbiosis disrupts homeostatic gut-liver axis function and is essential in the development of alcoholic liver disease. Here, we investigate changes in enteric microbiome composition in a model of early alcoholic steatohepatitis and dissect the pathogenic role of intestinal microbes in alcohol-induced liver pathology.

MATERIALS AND METHODS: Wild type mice received a 10-day diet that was either 5% alcohol-containing or an isocaloric control diet plus a single binge. 16S rDNA sequencing defined the bacterial communities in the cecum of alcohol- and pair-fed animals. Some mice were treated with an antibiotic cocktail prior to and throughout alcohol feeding. Liver ...


Impaired Osteogenesis Of T1dm Bone Marrow-Derived Stromal Cells And Periosteum-Derived Cells And Their Differential In-Vitro Responses To Growth Factor Rescue, Tera M. Filion, Jordan D. Skelly, Henry Huang, Dale L. Greiner, David C. Ayers, Jie Song Mar 2017

Impaired Osteogenesis Of T1dm Bone Marrow-Derived Stromal Cells And Periosteum-Derived Cells And Their Differential In-Vitro Responses To Growth Factor Rescue, Tera M. Filion, Jordan D. Skelly, Henry Huang, Dale L. Greiner, David C. Ayers, Jie Song

University of Massachusetts Medical School Faculty Publications

BACKGROUND: Poor bone quality, increased fracture risks, and impaired bone healing are orthopedic comorbidities of type 1 diabetes (T1DM). Standard osteogenic growth factor treatments are inadequate in fully rescuing retarded healing of traumatic T1DM long bone injuries where both periosteal and bone marrow niches are disrupted. We test the hypotheses that osteogenesis of bone marrow-derived stromal cells (BMSCs) and periosteum-derived cells (PDCs), two critical skeletal progenitors in long bone healing, are both impaired in T1DM and that they respond differentially to osteogenic bone morphogenetic proteins (BMPs) and/or insulin-like growth factor-1 (IGF-1) rescue.

METHODS: BMSCs and PDCs were isolated from ...


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 Estradiol-Inducible Promoter Enables Fast, Graduated Control Of Gene Expression In Fission Yeast, Makoto J. Ohira, David G. Hendrickson, R. Scott Mcisaac, Nicholas R. Rhind Feb 2017

An Estradiol-Inducible Promoter Enables Fast, Graduated Control Of Gene Expression In Fission Yeast, Makoto J. Ohira, David G. Hendrickson, R. Scott Mcisaac, Nicholas R. Rhind

University of Massachusetts Medical School Faculty Publications

The fission yeast Schizosaccharomyces pombe lacks a diverse toolkit of inducible promoters for experimental manipulation. Available inducible promoters suffer from slow induction kinetics, limited control of expression levels and/or a requirement for defined growth medium. In particular, no S. pombe inducible promoter systems exhibit a linear dose response, which would allow expression to be tuned to specific levels. We have adapted a fast, orthogonal promoter system with a large dynamic range and a linear dose response, based on β-estradiol-regulated function of the human estrogen receptor, for use in S. pombe. We show that this promoter system, termed Z3 ...