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Articles 1 - 11 of 11

Full-Text Articles in Cell Biology

Exosome-Mediated Delivery Of Rna Interference And Mirna Mimic, Fatemeh Momen-Heravi, Shashi Bala, Terence N. Bukong, Gyongyi Szabo Nov 2014

Exosome-Mediated Delivery Of Rna Interference And Mirna Mimic, Fatemeh Momen-Heravi, Shashi Bala, Terence N. Bukong, Gyongyi Szabo

Gyongyi Szabo

Exosomes, membranous nanovesicles, naturally carry bio-macromolecules and play pivotal roles in both physiological intercellular crosstalk and disease pathogenesis. Here, we showed that B cell-derived exosomes can function as vehicles to deliver exogenous miRNA-155 mimic or inhibitor into hepatocytes or macrophages, respectively. Stimulation of B cells significantly increased exosome production. Unlike in parental cells, baseline level of miRNA-155 was very low in exosomes derived from stimulated B cells. Exosomes loaded with a miRNA-155 mimic significantly increased miRNA-155 levels in primary mouse hepatocytes and the liver of miRNA-155 knockout mice. Treatment of RAW macrophages with miRNA-155 inhibitor loaded exosomes resulted in statistically ...


Enteroendocrine Cells Support Intestinal Stem-Cell-Mediated Homeostasis In Drosophila, Alla Amcheslavsky, Wei Song, Qi Li, Yingchao Nie, Ivan Bragatto, Dominique Ferrandon, Norbert Perrimon, Y. Tony Ip Oct 2014

Enteroendocrine Cells Support Intestinal Stem-Cell-Mediated Homeostasis In Drosophila, Alla Amcheslavsky, Wei Song, Qi Li, Yingchao Nie, Ivan Bragatto, Dominique Ferrandon, Norbert Perrimon, Y. Tony Ip

UMass Center for Clinical and Translational Science Supported Publications

Intestinal stem cells in the adult Drosophila midgut are regulated by growth factors produced from the surrounding niche cells including enterocytes and visceral muscle. The role of the other major cell type, the secretory enteroendocrine cells, in regulating intestinal stem cells remains unclear. We show here that newly eclosed scute loss-of-function mutant flies are completely devoid of enteroendocrine cells. These enteroendocrine cell-less flies have normal ingestion and fecundity but shorter lifespan. Moreover, in these newly eclosed mutant flies, the diet-stimulated midgut growth that depends on the insulin-like peptide 3 expression in the surrounding muscle is defective. The depletion of Tachykinin-producing ...


Tlr Sorting By Rab11 Endosomes Maintains Intestinal Epithelial-Microbial Homeostasis, Shiyan Yu, Yingchao Nie, Y. Tony Ip, Nan Gao Sep 2014

Tlr Sorting By Rab11 Endosomes Maintains Intestinal Epithelial-Microbial Homeostasis, Shiyan Yu, Yingchao Nie, Y. Tony Ip, Nan Gao

UMass Center for Clinical and Translational Science Supported Publications

Compartmentalization of Toll-like receptors (TLRs) in intestinal epithelial cells (IECs) regulates distinct immune responses to microbes; however, the specific cellular machinery that controls this mechanism has not been fully identified. Here we provide genetic evidences that the recycling endosomal compartment in enterocytes maintains a homeostatic TLR9 intracellular distribution, supporting mucosal tolerance to normal microbiota. Genetic ablation of a recycling endosome resident small GTPase, Rab11a, a gene adjacent to a Crohn's disease risk locus, in mouse IECs and in Drosophila midgut caused epithelial cell-intrinsic cytokine production, inflammatory bowel phenotype, and early mortality. Unlike wild-type controls, germ-free Rab11a-deficient mouse intestines failed ...


Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Leo Tsuda, Michele Markstein, Y. Tony Ip Jul 2014

Gene Expression Profiling Identifies The Zinc-Finger Protein Charlatan As A Regulator Of Intestinal Stem Cells In Drosophila, Alla Amcheslavsky, Yingchao Nie, Qi Li, Feng He, Leo Tsuda, Michele Markstein, Y. Tony Ip

UMass Center for Clinical and Translational Science Supported Publications

Intestinal stem cells (ISCs) in the adult Drosophila midgut can respond to tissue damage and support repair. We used genetic manipulation to increase the number of ISC-like cells in the adult midgut and performed gene expression profiling to identify potential ISC regulators. A detailed analysis of one of these potential regulators, the zinc-finger protein Charlatan, was carried out. MARCM clonal analysis and RNAi in precursor cells showed that loss of Chn function caused severe ISC division defects, including loss of EdU incorporation, phosphorylated histone 3 staining and expression of the mitotic protein Cdc2. Loss of Charlatan also led to a ...


Activin Limits Progenitor Capability By Promoting Epithelial Cell Differentiation In The Mammary Gland, Karen A. Dunphy, Thiruppavai Chandrasekaran, Niraj Bhatt, Michelle Chen, Amy L. Roberts, Mary Hagen, D. Joseph Jerry May 2014

Activin Limits Progenitor Capability By Promoting Epithelial Cell Differentiation In The Mammary Gland, Karen A. Dunphy, Thiruppavai Chandrasekaran, Niraj Bhatt, Michelle Chen, Amy L. Roberts, Mary Hagen, D. Joseph Jerry

UMass Center for Clinical and Translational Science Research Retreat

Transforming growth factor beta (TGF-beta) and activin utilize common signaling pathways, via smad2/3 and smad4, to mediate tumor suppression by effecting cell cycle arrest and apoptosis. Differences in temporal expression patterns suggest that each cytokine has specific roles in mammary gland development. Activin is expressed during pregnancy and lactation and is required for branching and lactogenesis, implying a role in mammary gland maturation. In contrast, TGF-beta is expressed during involution during mammary gland regression and functions to re-organize the mammary epithelial content to the non-lactating state. Previously, we found that TGF-beta and activin do share common signaling pathways allowing ...


High Performance Amphiphilic Polymer/Hydroxyapatite Composite Tissue Scaffolds, Artem B. Kutikov, Jie Song May 2014

High Performance Amphiphilic Polymer/Hydroxyapatite Composite Tissue Scaffolds, Artem B. Kutikov, Jie Song

UMass Center for Clinical and Translational Science Research Retreat

There is a critical clinical need for alternatives to autograft and allograft bone for over 500,000 bone grafting operations performed each year in the United States. Current synthetic bone grafts suffer from poor handling characteristics, brittle mechanical properties, and inconsistent bioactivity. By blending a biodegradable amphiphilic polymer with hydroxyapatite (HA), the main mineral component in bone, we developed an improved synthetic bone graft. The polymer/HA composites were fabricated in both 2-D and 3-D forms by electrospinning and 3-D printing. These materials exhibited unique handling characteristics such as high tensile elasticity (>200% failure strain) and self-stiffening properties upon hydration ...


Pericyte Nf-Κb Activation Enhances Endothelial Cell Proliferation And Proangiogenic Cytokine Secretion, Katherine E. Labarbera, Robert D. Hyldahl, Sarah Witkowski May 2014

Pericyte Nf-Κb Activation Enhances Endothelial Cell Proliferation And Proangiogenic Cytokine Secretion, Katherine E. Labarbera, Robert D. Hyldahl, Sarah Witkowski

UMass Center for Clinical and Translational Science Research Retreat

Pericytes are skeletal muscle resident, multipotent stem cells that are localized to capillaries. They respond to damage through activation of nuclear-factor kappa-B (NF-κB), a transcription factor that regulates many cellular processes including inflammation. Research has shown that pericyte NF-κB activation positively affects myoblast proliferation. It is unknown how pericyte NF-κB affects signaling and proliferation of endothelial cells, an important component of muscle tissue microcirculation.

PURPOSE: To determine the effects of altered pericyte NF-κB activity on endothelial cell proliferation and identify inflammatory factors involved in this cell-cell signaling.

METHODS: Human primary pericytes were transfected with vectors designed to increase or decrease ...


Exosome-Mediated Delivery Of Rna Interference And Mirna Mimic, Fatemeh Momen-Heravi, Shashi Bala, Terence N. Bukong, Gyongyi Szabo May 2014

Exosome-Mediated Delivery Of Rna Interference And Mirna Mimic, Fatemeh Momen-Heravi, Shashi Bala, Terence N. Bukong, Gyongyi Szabo

UMass Center for Clinical and Translational Science Research Retreat

Exosomes, membranous nanovesicles, naturally carry bio-macromolecules and play pivotal roles in both physiological intercellular crosstalk and disease pathogenesis. Here, we showed that B cell-derived exosomes can function as vehicles to deliver exogenous miRNA-155 mimic or inhibitor into hepatocytes or macrophages, respectively. Stimulation of B cells significantly increased exosome production. Unlike in parental cells, baseline level of miRNA-155 was very low in exosomes derived from stimulated B cells. Exosomes loaded with a miRNA-155 mimic significantly increased miRNA-155 levels in primary mouse hepatocytes and the liver of miRNA-155 knockout mice. Treatment of RAW macrophages with miRNA-155 inhibitor loaded exosomes resulted in statistically ...


Anti-Ppkcθ (T538) Delivery Via Cell Penetrating Peptide Mimics As A Novel Treatment Of Aplastic Anemia, Emrah Ilker Ozay, Gabriela Gonzalez-Perez, Joe Torres, Gregory N. Tew, Lisa M. Minter May 2014

Anti-Ppkcθ (T538) Delivery Via Cell Penetrating Peptide Mimics As A Novel Treatment Of Aplastic Anemia, Emrah Ilker Ozay, Gabriela Gonzalez-Perez, Joe Torres, Gregory N. Tew, Lisa M. Minter

UMass Center for Clinical and Translational Science Research Retreat

The objective of this study is to deliver anti-pPKCθ (T538) into T cells (hPBMCs) by using cell penetrating peptide mimics (CPPMs) to neutralize PKCθ activity both in vitro and in vivo, with the eventual goal of treating aplastic anemia (AA). AA is an immune-mediated bone marrow failure disease caused by T helper type 1 (Th1) autoimmune responses, which destroy blood cell progenitors. It was previously reported that protein kinase C theta (PKCθ), expressed specifically in T cells, plays an important role in T cell signaling by mediating Th1 differentiation. Mice treated with Rottlerin, a pharmacological inhibitor of PKCθ, are rescued ...


Multiple Approaches To Determine Toxicity Of Micro And Nano-Sized Titanium Dioxide Materials When Exposed To Human Red Blood Cells, Aaron Stella, Shu-Feng Hsieh, Dhimiter Bello, Daniel Schmidt, Eugene Rodgers May 2014

Multiple Approaches To Determine Toxicity Of Micro And Nano-Sized Titanium Dioxide Materials When Exposed To Human Red Blood Cells, Aaron Stella, Shu-Feng Hsieh, Dhimiter Bello, Daniel Schmidt, Eugene Rodgers

UMass Center for Clinical and Translational Science Research Retreat

Introduction: The utility of engineered nanomaterials’ is growing, particularly the titanium dioxide (TiO2) polymorphs. TiO2 is very useful for brightening paints, and coloring foods. Nano-sized TiO2 is also useful for sunscreens, cosmetics, and can be utilized as a photocatalyst. However, the nanometer size and the large specific surface area of the TiO2 materials are physicochemical characteristics which may contribute to human red blood cell (RBC) damage. Using RBCs as a cellular model, we have evaluated the effects of TiO2 nanoparticle exposure to RBCs by quantifying oxidized glutathione, oxidized membrane vitamin E, hemolysis, hemoglobin adsorption, and cellular aggregation. Results: Red blood ...


Transdifferentiation Of Α- To Β-Cells Is Enhanced In Fstl3 Ko Mice, Alan Schneyer, Danielle Andrzejewski, Amy Burnside, Melissa Brown May 2014

Transdifferentiation Of Α- To Β-Cells Is Enhanced In Fstl3 Ko Mice, Alan Schneyer, Danielle Andrzejewski, Amy Burnside, Melissa Brown

UMass Center for Clinical and Translational Science Research Retreat

Both type 1 and type 2 diabetes involve loss of functional pancreatic B-cells which is driving research into potential replacement sources. Expansion of functional B-cell mass, such as through induction of B-cell neogenesis or through transdifferentiation of A-cells into functional B-cells represent appealing therapeutic solutions to restoring glucose control. To date, however, these processes have been induced through genetic manipulation or severe pancreatic injury. It remains to be determined whether transdifferentiation or neogenesis contribute to functional B-cell mass under normal physiological conditions and/or contribute to B-cell expansion and how these processes are regulated.

We have reported that inactivation of ...