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Articles 1 - 30 of 3647

Full-Text Articles in Life Sciences

Principles For Enhancing Virus Capsid Capacity And Stability From A Thermophilic Virus Capsid Structure, Nicholas P. Stone, Gabriel Demo, Emily Agnello, Brian A. Kelch Jan 2019

Principles For Enhancing Virus Capsid Capacity And Stability From A Thermophilic Virus Capsid Structure, Nicholas P. Stone, Gabriel Demo, Emily Agnello, Brian A. Kelch

University of Massachusetts Medical School Faculty Publications

The capsids of double-stranded DNA viruses protect the viral genome from the harsh extracellular environment, while maintaining stability against the high internal pressure of packaged DNA. To elucidate how capsids maintain stability in an extreme environment, we used cryoelectron microscopy to determine the capsid structure of the thermostable phage P74-26. We find the P74-26 capsid exhibits an overall architecture that is very similar to those of other tailed bacteriophages, allowing us to directly compare structures to derive the structural basis for enhanced stability. Our structure reveals lasso-like interactions that appear to function like catch bonds. This architecture allows the capsid ...


Debrowser: Interactive Differential Expression Analysis And Visualization Tool For Count Data, Alper Kucukural, Onur Yukselen, Deniz M. Ozata, Melissa J. Moore, Manuel Garber Jan 2019

Debrowser: Interactive Differential Expression Analysis And Visualization Tool For Count Data, Alper Kucukural, Onur Yukselen, Deniz M. Ozata, Melissa J. Moore, Manuel Garber

Program in Bioinformatics and Integrative Biology Publications and Presentations

BACKGROUND: Sequencing data has become a standard measure of diverse cellular activities. For example, gene expression is accurately measured by RNA sequencing (RNA-Seq) libraries, protein-DNA interactions are captured by chromatin immunoprecipitation sequencing (ChIP-Seq), protein-RNA interactions by crosslinking immunoprecipitation sequencing (CLIP-Seq) or RNA immunoprecipitation (RIP-Seq) sequencing, DNA accessibility by assay for transposase-accessible chromatin (ATAC-Seq), DNase or MNase sequencing libraries. The processing of these sequencing techniques involves library-specific approaches. However, in all cases, once the sequencing libraries are processed, the result is a count table specifying the estimated number of reads originating from each genomic locus. Differential analysis to determine which loci ...


Human Islets Expressing Hnf1a Variant Have Defective Beta Cell Transcriptional Regulatory Networks, Rachana Haliyur, Sambra D. Redick, David M. Harlan, Alvin C. Powers Jan 2019

Human Islets Expressing Hnf1a Variant Have Defective Beta Cell Transcriptional Regulatory Networks, Rachana Haliyur, Sambra D. Redick, David M. Harlan, Alvin C. Powers

Open Access Articles

Using an integrated approach to characterize the pancreatic tissue and isolated islets from a 33-year-old with 17 years of type 1 diabetes (T1D), we found that donor islets contained beta cells without insulitis and lacked glucose-stimulated insulin secretion despite a normal insulin response to cAMP-evoked stimulation. With these unexpected findings for T1D, we sequenced the donor DNA and found a pathogenic heterozygous variant in the gene encoding hepatocyte nuclear factor-1alpha (HNF1A). In one of the first studies of human pancreatic islets with a disease-causing HNF1A variant associated with the most common form of monogenic diabetes, we found that HNF1A dysfunction ...


Toll-Like Receptor-4 Disruption Suppresses Adipose Tissue Remodeling And Increases Survival In Cancer Cachexia Syndrome, Felipe Henriques, Magno A. Lopes, Felipe O. Franco, Pamela Knobl, Kaltinaitis B. Santos, Luana L. Bueno, Victor A. Correa, Alexander H. Bedard, Adilson L. Guilherme, Alexander Birbrair, Sidney B. Peres, Stephen R. Farmer, Miguel L. Batista Jr. Dec 2018

Toll-Like Receptor-4 Disruption Suppresses Adipose Tissue Remodeling And Increases Survival In Cancer Cachexia Syndrome, Felipe Henriques, Magno A. Lopes, Felipe O. Franco, Pamela Knobl, Kaltinaitis B. Santos, Luana L. Bueno, Victor A. Correa, Alexander H. Bedard, Adilson L. Guilherme, Alexander Birbrair, Sidney B. Peres, Stephen R. Farmer, Miguel L. Batista Jr.

Open Access Articles

Cancer-induced cachexia, characterized by systemic inflammation, body weight loss, adipose tissue (AT) remodeling and muscle wasting, is a malignant metabolic syndrome with undefined etiology. Here, we show that both genetic ablation and pharmacological inhibition of TLR4 were able to attenuate the main clinical markers of cachexia in mice bearing Lewis lung carcinoma (LLC). AT remodelling was not found in LLC tumor-bearing (TB) TLR4(-/-) mice due to reduced macrophage infiltration and adipocyte atrophy. TLR4(-/-) mice were also resistant to cold-induced browning of subcutaneous AT (scAT). Importantly, pharmacological inhibition of TLR4 (Atorvastatin) reproduced the main protective effect against AT remodeling found in ...


The Trim-Nhl Protein Nhl-2 Is A Co-Factor In The Nuclear And Somatic Rnai Pathways In C. Elegans, Gregory M. Davis, Shikui Tu, Jacqueline A. Wilce, Julie M. Claycomb, Zhiping Weng, Peter R. Boag Dec 2018

The Trim-Nhl Protein Nhl-2 Is A Co-Factor In The Nuclear And Somatic Rnai Pathways In C. Elegans, Gregory M. Davis, Shikui Tu, Jacqueline A. Wilce, Julie M. Claycomb, Zhiping Weng, Peter R. Boag

Program in Bioinformatics and Integrative Biology Publications and Presentations

Proper regulation of germline gene expression is essential for fertility and maintaining species integrity. In the C. elegans germline, a diverse repertoire of regulatory pathways promote the expression of endogenous germline genes and limit the expression of deleterious transcripts to maintain genome homeostasis. Here we show that the conserved TRIM-NHL protein, NHL-2, plays an essential role in the C. elegans germline, modulating germline chromatin and meiotic chromosome organization. We uncover a role for NHL-2 as a co-factor in both positively (CSR-1) and negatively (HRDE-1) acting germline 22G-small RNA pathways and the somatic nuclear RNAi pathway. Furthermore, we demonstrate that NHL-2 ...


Behind Emammal’S Success: A Data Curator With A Data Standard, Jennifer Y. Zhao, William J. Mcshea Dec 2018

Behind Emammal’S Success: A Data Curator With A Data Standard, Jennifer Y. Zhao, William J. Mcshea

Journal of eScience Librarianship

This paper explores the data challenges of a major collection method in the field of ecology: using infrared-activated cameras to detect wildlife. One such solution, eMammal, is now available to address these struggles. We delineate the key reason behind its success: a data curator who manages an established data standard and communicates with eMammal’s users and stakeholders. We outline the tasks of this data curator, mention how they can work with data librarians, and demonstrate that the data curator position is already applicable in several biological science fields with a few examples. We end by emphasizing the growth of ...


Hla-Do Modulates The Diversity Of The Mhc-Ii Self-Peptidome, Padma P. Nanaware, Mollie M. Jurewicz, John D. Leszyk, Scott A. Shaffer, Lawrence J. Stern Dec 2018

Hla-Do Modulates The Diversity Of The Mhc-Ii Self-Peptidome, Padma P. Nanaware, Mollie M. Jurewicz, John D. Leszyk, Scott A. Shaffer, Lawrence J. Stern

Open Access Articles

Presentation of antigenic peptides on MHC-II molecules is essential for tolerance to self and for initiation of immune responses against foreign antigens. DO (HLA-DO in humans, H2-O in mice) is a non-classical MHC-II protein that has been implicated in control of autoimmunity and regulation of neutralizing antibody responses to viruses. These effects likely are related to a role of DO in selecting MHC-II epitopes, but previous studies examining the effect of DO on presentation of selected CD4 T cell epitopes have been contradictory. To understand how DO modulates MHC-II antigen presentation, we characterized the full spectrum of peptides presented by ...


Protective Versus Pathologic Pre-Exposure Cytokine Profiles In Dengue Virus Infection, Heather Friberg, Coreen M. Beaumier, Sangshin Park, Pamela P. Pazoles, Timothy P. Endy, Anuja Mathew, Jeffrey R. Currier, Richard G. Jarman, Kathryn B. Anderson, Steven Hatch, Stephen J. Thomas, Alan L. Rothman Dec 2018

Protective Versus Pathologic Pre-Exposure Cytokine Profiles In Dengue Virus Infection, Heather Friberg, Coreen M. Beaumier, Sangshin Park, Pamela P. Pazoles, Timothy P. Endy, Anuja Mathew, Jeffrey R. Currier, Richard G. Jarman, Kathryn B. Anderson, Steven Hatch, Stephen J. Thomas, Alan L. Rothman

Open Access Articles

BACKGROUND: Hyperendemic circulation of all four types of dengue virus (DENV-1-4) has expanded globally, fueling concern for increased incidence of severe dengue. While the majority of DENV infections are subclinical, epidemiologic studies suggest that type-cross-reactive immunity can influence disease outcome in subsequent infections. The mechanisms controlling these differential clinical outcomes remain poorly defined.

METHODOLOGY/PRINCIPAL FINDINGS: Blood samples were collected from a cohort of school-aged Thai children who subsequently experienced a subclinical DENV infection or developed dengue illness. PBMC collected prior to infection were stimulated in vitro with DENV and the secretion of 30 cytokines was measured using a multiplexed ...


Cpla2alpha-/- Sympathetic Neurons Exhibit Increased Membrane Excitability And Loss Of N-Type Ca2+ Current Inhibition By M1 Muscarinic Receptor Signaling, Liwang Liu, Joseph V. Bonventre, Ann R. Rittenhouse Dec 2018

Cpla2alpha-/- Sympathetic Neurons Exhibit Increased Membrane Excitability And Loss Of N-Type Ca2+ Current Inhibition By M1 Muscarinic Receptor Signaling, Liwang Liu, Joseph V. Bonventre, Ann R. Rittenhouse

Open Access Articles

Group IVa cytosolic phospholipase A2 (cPLA2alpha) mediates GPCR-stimulated arachidonic acid (AA) release from phosphatidylinositol 4,5-bisphosphate (PIP2) located in plasma membranes. We previously found in superior cervical ganglion (SCG) neurons that PLA2 activity is required for voltage-independent N-type Ca2+ (N-) current inhibition by M1 muscarinic receptors (M1Rs). These findings are at odds with an alternative model, previously observed for M-current inhibition, where PIP2 dissociation from channels and subsequent metabolism by phospholipase C suffices for current inhibition. To resolve cPLA2alpha's importance, we have investigated its role in mediating voltage-independent N-current inhibition (~40%) that follows application of the muscarinic agonist oxotremorine-M ...


Membrane Protein Nanoparticles: The Shape Of Things To Come, Kailene S. Simon, Naomi L. Pollock, Sarah C. Lee Dec 2018

Membrane Protein Nanoparticles: The Shape Of Things To Come, Kailene S. Simon, Naomi L. Pollock, Sarah C. Lee

Open Access Articles

The use of styrene-maleic acid (SMA) for the purification of a wide range of membrane proteins (MPs) from both prokaryotic and eukaryotic sources has begun to make an impact in the field of MP biology. This method is growing in popularity as a means to purify and thoroughly investigate the structure and function of MPs and biological membranes. The amphiphilic SMA copolymer can effectively extract MPs directly from a native lipid bilayer to form discs approximately 10 nm in diameter. The resulting lipid particles, or styrene-maleic acid lipid particles (SMALPs), contain SMA, protein and membrane lipid. MPs purified in SMALPs ...


Resistance From Afar: Distal Mutation V36m Allosterically Modulates The Active Site To Accentuate Drug Resistance In Hcv Ns3/4a Protease, Aysegul Ozen, Kuan-Hung Lin, Keith P. Romano, Davide Tavella, Alicia Newton, Christos J. Petropoulos, Wei Huang, Cihan Aydin, Celia A. Schiffer Dec 2018

Resistance From Afar: Distal Mutation V36m Allosterically Modulates The Active Site To Accentuate Drug Resistance In Hcv Ns3/4a Protease, Aysegul Ozen, Kuan-Hung Lin, Keith P. Romano, Davide Tavella, Alicia Newton, Christos J. Petropoulos, Wei Huang, Cihan Aydin, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Hepatitis C virus rapidly evolves, conferring resistance to direct acting antivirals. While resistance via active site mutations in the viral NS3/4A protease has been well characterized, the mechanism for resistance of non-active site mutations is unclear. R155K and V36M often co-evolve and while R155K alters the electrostatic network at the binding site, V36M is more than 13 Angstrom away. In this study the mechanism by which V36M confers resistance, in the context of R155K, is elucidated with drug susceptibility assays, crystal structures, and molecular dynamics (MD) simulations for three protease inhibitors: telaprevir, boceprevir and danoprevir. The R155K and R155K ...


Intron-Containing Rna From The Hiv-1 Provirus Activates Type I Interferon And Inflammatory Cytokines, Sean M. Mccauley, Kyusik Kim, Anetta Nowosielska, Ann Dauphin, Leonid Yurkovetskiy, William E. Diehl, Jeremy Luban Dec 2018

Intron-Containing Rna From The Hiv-1 Provirus Activates Type I Interferon And Inflammatory Cytokines, Sean M. Mccauley, Kyusik Kim, Anetta Nowosielska, Ann Dauphin, Leonid Yurkovetskiy, William E. Diehl, Jeremy Luban

Open Access Articles

HIV-1-infected people who take drugs that suppress viremia to undetectable levels are protected from developing AIDS. Nonetheless, HIV-1 establishes proviruses in long-lived CD4(+) memory T cells, and perhaps other cell types, that preclude elimination of the virus even after years of continuous antiviral therapy. Here we show that the HIV-1 provirus activates innate immune signaling in isolated dendritic cells, macrophages, and CD4(+) T cells. Immune activation requires transcription from the HIV-1 provirus and expression of CRM1-dependent, Rev-dependent, RRE-containing, unspliced HIV-1 RNA. If rev is provided in trans, all HIV-1 coding sequences are dispensable for activation except those cis-acting sequences required ...


Manganese Influx And Expression Of Zip8 Is Essential In Primary Myoblasts And Contributes To Activation Of Sod2, Shellaina J. V. Gordon, Daniel E. Fenker, Katherine E. Vest, Teresita Padilla-Benavides Dec 2018

Manganese Influx And Expression Of Zip8 Is Essential In Primary Myoblasts And Contributes To Activation Of Sod2, Shellaina J. V. Gordon, Daniel E. Fenker, Katherine E. Vest, Teresita Padilla-Benavides

University of Massachusetts Medical School Faculty Publications

Trace elements such as copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) are enzyme cofactors and second messengers in cell signaling. Trace elements are emerging as key regulators of differentiation and development of mammalian tissues including blood, brain, and skeletal muscle. We previously reported an influx of Cu and dynamic expression of various metal transporters during differentiation of skeletal muscle cells. Here, we demonstrate that during differentiation of skeletal myoblasts an increase of additional trace elements such as Mn, Fe and Zn occurs. Interestingly the Mn increase is concomitant with increased Mn-dependent SOD2 levels. To better understand the Mn ...


Orbit: A New Paradigm For Genetic Engineering Of Mycobacterial Chromosomes, Kenan C. Murphy, Samantha J. Nelson, Subhalaxmi Nambi, Kadamba Papavinasasundaram, Christina E. Baer, Christopher M. Sassetti Dec 2018

Orbit: A New Paradigm For Genetic Engineering Of Mycobacterial Chromosomes, Kenan C. Murphy, Samantha J. Nelson, Subhalaxmi Nambi, Kadamba Papavinasasundaram, Christina E. Baer, Christopher M. Sassetti

Open Access Articles

Two efficient recombination systems were combined to produce a versatile method for chromosomal engineering that obviates the need to prepare double-stranded DNA (dsDNA) recombination substrates. A synthetic "targeting oligonucleotide" is incorporated into the chromosome via homologous recombination mediated by the phage Che9c RecT annealase. This oligonucleotide contains a site-specific recombination site for the directional Bxb1 integrase (Int), which allows the simultaneous integration of a "payload plasmid" that contains a cognate recombination site and a selectable marker. The targeting oligonucleotide and payload plasmid are cotransformed into a RecT- and Int-expressing strain, and drug-resistant homologous recombinants are selected in a single step ...


The Caenorhabditis Elegans Oxidative Stress Response Requires The Nhr-49 Transcription Factor, Queenie Hu, Dayana R. D'Amora, Lesley T. Macneil, Albertha J. M. Walhout, Terrance J. Kubiseski Dec 2018

The Caenorhabditis Elegans Oxidative Stress Response Requires The Nhr-49 Transcription Factor, Queenie Hu, Dayana R. D'Amora, Lesley T. Macneil, Albertha J. M. Walhout, Terrance J. Kubiseski

Open Access Articles

The overproduction of reactive oxygen species (ROS) in cells can lead to the development of diseases associated with aging. We have previously shown that C. elegans BRAP-2 (Brca1 associated binding protein 2) regulates phase II detoxification genes such as gst-4, by increasing SKN-1 activity. Previously, a transcription factor (TF) RNAi screen was conducted to identify potential activators that are required to induce gst-4 expression in brap-2(ok1492) mutants. The lipid metabolism regulator NHR-49/HNF4 was among 18 TFs identified. Here, we show that knockdown of nhr-49 suppresses the activation of gst-4 caused by brap-2 inactivation and that gain-of-function alleles of ...


Conserved Mrna-Granule Component Scd6 Targets Dhh1 To Repress Translation Initiation And Activates Dcp2-Mediated Mrna Decay In Vivo, Quira Zeidan, Feng He, Fan Zhang, Hongen Zhang, Allan Jacobson, Alan G. Hinnebusch Dec 2018

Conserved Mrna-Granule Component Scd6 Targets Dhh1 To Repress Translation Initiation And Activates Dcp2-Mediated Mrna Decay In Vivo, Quira Zeidan, Feng He, Fan Zhang, Hongen Zhang, Allan Jacobson, Alan G. Hinnebusch

Open Access Articles

Scd6 protein family members are evolutionarily conserved components of translationally silent mRNA granules. Yeast Scd6 interacts with Dcp2 and Dhh1, respectively a subunit and a regulator of the mRNA decapping enzyme, and also associates with translation initiation factor eIF4G to inhibit translation in cell extracts. However, the role of Scd6 in mRNA turnover and translational repression in vivo is unclear. We demonstrate that tethering Scd6 to a GFP reporter mRNA reduces mRNA abundance via Dcp2 and suppresses reporter mRNA translation via Dhh1. Thus, in a dcp2Delta mutant, tethered Scd6 reduces GFP protein expression with little effect on mRNA abundance, whereas ...


Peptidylarginine Deiminases 2 And 4 Modulate Innate And Adaptive Immune Responses In Tlr-7-Dependent Lupus., Yudong Liu, Yaíma L Lightfoot, Nickie Seto, Santanu Mondal, Padmavathy Nandha Premnath, Paul R. Thompson Dec 2018

Peptidylarginine Deiminases 2 And 4 Modulate Innate And Adaptive Immune Responses In Tlr-7-Dependent Lupus., Yudong Liu, Yaíma L Lightfoot, Nickie Seto, Santanu Mondal, Padmavathy Nandha Premnath, Paul R. Thompson

University of Massachusetts Medical School Publications

The peptidylarginine deiminases PAD2 and PAD4 are implicated in the pathogenesis of several autoimmune diseases. PAD4 may be pathogenic in systemic lupus erythematosus (SLE) through its role in neutrophil extracellular trap (NET) formation that promotes autoantigen externalization, immune dysregulation, and organ damage. The role of this enzyme in mouse models of autoimmunity remains unclear, as pan-PAD chemical inhibitors improve clinical phenotype, whereas PAD4-KO models have given conflicting results. The role of PAD2 in SLE has not been investigated. The differential roles of PAD2 and PAD4 in TLR-7-dependent lupus autoimmunity were examined. Padi4-/- displayed decreased autoantibodies, type I IFN responses, immune ...


General Decapping Activators Target Different Subsets Of Inefficiently Translated Mrnas, Feng He, Alper Celik, Chan Wu, Allan Jacobson Dec 2018

General Decapping Activators Target Different Subsets Of Inefficiently Translated Mrnas, Feng He, Alper Celik, Chan Wu, Allan Jacobson

Open Access Articles

The Dcp1-Dcp2 decapping enzyme and the decapping activators Pat1, Dhh1, and Lsm1 regulate mRNA decapping, but their mechanistic integration is unknown. We analyzed the gene expression consequences of deleting PAT1, LSM1, or DHH1, or the DCP2 C-terminal domain, and found that: i) the Dcp2 C-terminal domain is an effector of both negative and positive regulation; ii) rather than being global activators of decapping, Pat1, Lsm1, and Dhh1 directly target specific subsets of yeast mRNAs and loss of the functions of each of these factors has substantial indirect consequences for genome-wide mRNA expression; and iii) transcripts targeted by Pat1, Lsm1, and ...


Trisomy Silencing By Xist Normalizes Down Syndrome Cell Pathogenesis Demonstrated For Hematopoietic Defects In Vitro, Jen-Chieh Chiang, Jun Jiang, Peter E. Newburger, Jeanne B. Lawrence Dec 2018

Trisomy Silencing By Xist Normalizes Down Syndrome Cell Pathogenesis Demonstrated For Hematopoietic Defects In Vitro, Jen-Chieh Chiang, Jun Jiang, Peter E. Newburger, Jeanne B. Lawrence

Open Access Articles

We previously demonstrated that an integrated XIST transgene can broadly repress one chromosome 21 in Down syndrome (DS) pluripotent cells. Here we address whether trisomy-silencing can normalize cell function and development sufficiently to correct cell pathogenesis, tested in an in vitro model of human fetal hematopoiesis, for which DS cellular phenotypes are best known. XIST induction in four transgenic clones reproducibly corrected over-production of megakaryocytes and erythrocytes, key to DS myeloproliferative disorder and leukemia. A contrasting increase in neural stem and iPS cells shows cell-type specificity, supporting this approach successfully rebalances the hematopoietic developmental program. Given this, we next used ...


Nmecas9 Is An Intrinsically High-Fidelity Genome-Editing Platform, Nadia Amrani, Xin D. Gao, Pengpeng Liu, Alireza Edraki, Aamir Mir, Raed Ibraheim, Ankit Gupta, Kanae E. Sasaki, Tong Wu, Thomas G. Fazzio, Lihua Julie Zhu, Scot A. Wolfe, Erik J. Sontheimer Dec 2018

Nmecas9 Is An Intrinsically High-Fidelity Genome-Editing Platform, Nadia Amrani, Xin D. Gao, Pengpeng Liu, Alireza Edraki, Aamir Mir, Raed Ibraheim, Ankit Gupta, Kanae E. Sasaki, Tong Wu, Thomas G. Fazzio, Lihua Julie Zhu, Scot A. Wolfe, Erik J. Sontheimer

Open Access Articles

BACKGROUND: The development of CRISPR genome editing has transformed biomedical research. Most applications reported thus far rely upon the Cas9 protein from Streptococcus pyogenes SF370 (SpyCas9). With many RNA guides, wildtype SpyCas9 can induce significant levels of unintended mutations at near-cognate sites, necessitating substantial efforts toward the development of strategies to minimize off-target activity. Although the genome-editing potential of thousands of other Cas9 orthologs remains largely untapped, it is not known how many will require similarly extensive engineering to achieve single-site accuracy within large genomes. In addition to its off-targeting propensity, SpyCas9 is encoded by a relatively large open reading ...


Potent Cas9 Inhibition In Bacterial And Human Cells By Acriic4 And Acriic5 Anti-Crispr Proteins, Jooyoung Lee, Aamir Mir, Alireza Edraki, Bianca Garcia, Nadia Amrani, Hannah E. Lou, Ildar Gainetdinov, April Pawluk, Raed Ibraheim, Xin D. Gao, Pengpeng Liu, Alan R. Davidson, Karen L. Maxwell, Erik J. Sontheimer Dec 2018

Potent Cas9 Inhibition In Bacterial And Human Cells By Acriic4 And Acriic5 Anti-Crispr Proteins, Jooyoung Lee, Aamir Mir, Alireza Edraki, Bianca Garcia, Nadia Amrani, Hannah E. Lou, Ildar Gainetdinov, April Pawluk, Raed Ibraheim, Xin D. Gao, Pengpeng Liu, Alan R. Davidson, Karen L. Maxwell, Erik J. Sontheimer

Open Access Articles

In their natural settings, CRISPR-Cas systems play crucial roles in bacterial and archaeal adaptive immunity to protect against phages and other mobile genetic elements, and they are also widely used as genome engineering technologies. Previously we discovered bacteriophage-encoded Cas9-specific anti-CRISPR (Acr) proteins that serve as countermeasures against host bacterial immunity by inactivating their CRISPR-Cas systems (A. Pawluk, N. Amrani, Y. Zhang, B. Garcia, et al., Cell 167:1829-1838.e9, 2016, https://doi.org/10.1016/j.cell.2016.11.017). We hypothesized that the evolutionary advantages conferred by anti-CRISPRs would drive the widespread occurrence of these proteins in nature (K ...


Two Contrasting Classes Of Nucleolus-Associated Domains In Mouse Fibroblast Heterochromatin, Anastassiia Vertii, Jianhong Ou, Jun Yu, Aimin Yan, Hervé Pagès, Haibo Liu, Lihua Julie Zhu, Paul D. Kaufman Dec 2018

Two Contrasting Classes Of Nucleolus-Associated Domains In Mouse Fibroblast Heterochromatin, Anastassiia Vertii, Jianhong Ou, Jun Yu, Aimin Yan, Hervé Pagès, Haibo Liu, Lihua Julie Zhu, Paul D. Kaufman

University of Massachusetts Medical School Faculty Publications

In interphase eukaryotic cells, almost all heterochromatin is located adjacent to the nucleolus or to the nuclear lamina, thus defining Nucleolus Associated Domains (NADs) and Lamina Associated Domains (LADs), respectively. Here, we determined the first genome-scale map of murine NADs in mouse embryonic fibroblasts (MEFs) via deep sequencing of chromatin associated with purified nucleoli. We developed a Bioconductor package called NADfinder and demonstrated that it identifies NADs more accurately than other peak-calling tools, due to its critical feature of chromosome-level local baseline correction. We detected two distinct classes of NADs. Type I NADs associate frequently with both the nucleolar periphery ...


Molecular Mechanisms Directing Spine Outgrowth And Synaptic Partner Selection In Caenorhabditis Elegans, Devyn Oliver, Kellianne Alexander, Michael M. Francis Dec 2018

Molecular Mechanisms Directing Spine Outgrowth And Synaptic Partner Selection In Caenorhabditis Elegans, Devyn Oliver, Kellianne Alexander, Michael M. Francis

Open Access Articles

The development of the nervous system requires precise outgrowth, extension, and wiring of both axons and dendrites to generate properly functioning neural circuits. The molecular mechanisms that shape neurite development, in particular dendritic development, remain incompletely understood. Dendrites are often highly branched and coated with actin-filled, thorny protrusions, called dendritic spines, that allow for increased numbers of synaptic contacts with neighboring neurons. Disruptions in dendritic spine development have been implicated in many neurological disorders such as autism, schizophrenia, and Alzheimer's disease. Although the development of dendritic spines is vital for cognitive function, understanding the mechanisms driving their outgrowth and ...


Ectopic High Endothelial Venules In Pancreatic Ductal Adenocarcinoma: A Unique Site For Targeted Delivery, Baharak Bahmani, Mayuko Uehara, Farideh Ordikhani, Xiaofei Li, Liwei Jiang, Naima Banouni, Takaharu Ichimura, Vivek Kasinath, Siawosh K. Eskandari, Nasim Annabi, Jonathan S. Bromberg, Leonard D. Shultz, Dale L. Greiner, Reza Abdi Dec 2018

Ectopic High Endothelial Venules In Pancreatic Ductal Adenocarcinoma: A Unique Site For Targeted Delivery, Baharak Bahmani, Mayuko Uehara, Farideh Ordikhani, Xiaofei Li, Liwei Jiang, Naima Banouni, Takaharu Ichimura, Vivek Kasinath, Siawosh K. Eskandari, Nasim Annabi, Jonathan S. Bromberg, Leonard D. Shultz, Dale L. Greiner, Reza Abdi

Open Access Articles

BACKGROUND: Nanomedicine offers an excellent opportunity to tackle treatment-refractory malignancies by enhancing the delivery of therapeutics to the tumor site. High endothelial venules (HEVs) are found primarily in lymph nodes or formed de novo in peripheral tissues during inflammatory responses. They express peripheral node addressin (PNAd), which is recognized by the monoclonal antibody MECA79.

METHODS: Here, we demonstrated that HEVs form de novo in human pancreatic ductal adenocarcinoma (PDAC). We engineered MECA79 coated nanoparticles (MECA79-NPs) that recognize these ectopic HEVs in PDAC.

FINDINGS: The trafficking of MECA79-NPs following intravenous delivery to human PDAC implanted in a humanized mouse model was ...


Dynamic Balance Measurement And Quantitative Assessment Using Wearable Plantar-Pressure Insoles In A Pose-Sensed Virtual Environment, Cunguang Lou, Chenyao Pang, Congrui Jing, Shuo Wang, Xufeng He, Xiaoguang Liu, Lei Huang, Feng Lin, Xiuling Liu, Hongrui Wang Nov 2018

Dynamic Balance Measurement And Quantitative Assessment Using Wearable Plantar-Pressure Insoles In A Pose-Sensed Virtual Environment, Cunguang Lou, Chenyao Pang, Congrui Jing, Shuo Wang, Xufeng He, Xiaoguang Liu, Lei Huang, Feng Lin, Xiuling Liu, Hongrui Wang

Open Access Articles

The center of plantar pressure (COP) reflects the dynamic balance of subjects to a certain extent. In this study, wearable pressure insoles are designed, body pose measure is detected by the Kinect sensor, and a balance evaluation system is formulated. With the designed games for the interactive actions, the Kinect sensor reads the skeletal poses to judge whether the desired action is performed, and the pressure insoles simultaneously collect the plantar pressure data. The COP displacement and its speed are calculated to determine the body sway and the ability of balance control. Significant differences in the dispersion of the COP ...


Identification Of Deubiquitinating Enzymes That Control The Cell Cycle In Saccharomyces Cerevisiae, Claudine E. Mapa Nov 2018

Identification Of Deubiquitinating Enzymes That Control The Cell Cycle In Saccharomyces Cerevisiae, Claudine E. Mapa

GSBS Dissertations and Theses

A large fraction of the proteome displays cell cycle-dependent expression, which is important for cells to accurately grow and divide. Cyclical protein expression requires protein degradation via the ubiquitin proteasome system (UPS), and several ubiquitin ligases (E3) have established roles in this regulation. Less is understood about the roles of deubiquitinating enzymes (DUB), which antagonize E3 activity. A few DUBs have been shown to interact with and deubiquitinate cell cycle-regulatory E3s and their protein substrates, suggesting DUBs play key roles in cell cycle control. However, in vitro studies and characterization of individual DUB deletion strains in yeast suggest that these ...


Stress-Responsive And Metabolic Gene Regulation Are Altered In Low S-Adenosylmethionine, Wei Ding, Daniel P. Higgins, Dilip K. Yadav, Adwait A. Godbole, Read Pukkila-Worley, Amy K. Walker Nov 2018

Stress-Responsive And Metabolic Gene Regulation Are Altered In Low S-Adenosylmethionine, Wei Ding, Daniel P. Higgins, Dilip K. Yadav, Adwait A. Godbole, Read Pukkila-Worley, Amy K. Walker

Open Access Articles

S-adenosylmethionine (SAM) is a donor which provides the methyl groups for histone or nucleic acid modification and phosphatidylcholine production. SAM is hypothesized to link metabolism and chromatin modification, however, its role in acute gene regulation is poorly understood. We recently found that Caenorhabditis elegans with reduced SAM had deficiencies in H3K4 trimethylation (H3K4me3) at pathogen-response genes, decreasing their expression and limiting pathogen resistance. We hypothesized that SAM may be generally required for stress-responsive transcription. Here, using genetic assays, we show that transcriptional responses to bacterial or xenotoxic stress fail in C. elegans with low SAM, but that expression of heat ...


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 ...


Targeted Delivery Of Bioactive Molecules For Vascular Intervention And Tissue Engineering, Hannah A. Strobel, Elisabet I. Qendro, Eben Alsberg, Marsha W. Rolle Nov 2018

Targeted Delivery Of Bioactive Molecules For Vascular Intervention And Tissue Engineering, Hannah A. Strobel, Elisabet I. Qendro, Eben Alsberg, Marsha W. Rolle

Open Access Articles

Cardiovascular diseases are the leading cause of death in the United States. Treatment often requires surgical interventions to re-open occluded vessels, bypass severe occlusions, or stabilize aneurysms. Despite the short-term success of such interventions, many ultimately fail due to thrombosis or restenosis (following stent placement), or incomplete healing (such as after aneurysm coil placement). Bioactive molecules capable of modulating host tissue responses and preventing these complications have been identified, but systemic delivery is often harmful or ineffective. This review discusses the use of localized bioactive molecule delivery methods to enhance the long-term success of vascular interventions, such as drug-eluting stents ...


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 ...