Muscle Cell News Volume 1.08 | May 2 2016

Effects of Matrix Metalloproteinases on the Performance of Platelet Fibrin Gel Spiked with Cardiac Stem Cells in Heart Repair
Investigators elucidated the effects of matrix metalloproteinase inhibition on the therapeutic benefits of intramyocardial injection of platelet fibrin gel spiked with cardiac stem cells in a rat model of acute myocardial infarction. [Stem Cells Transl Med] Abstract

Induction of Human iPSC-Derived Cardiomyocyte Proliferation Revealed by Combinatorial Screening in High Density Microbioreactor Arrays
Scientists used high-density microbioreactor arrays to combinatorially screen Wnt, Hedgehog, IGF and FGF pathway agonists. The Wnt activator CHIR99021 was identified as the most potent molecular inducer of human cardiomyocyte proliferation, inducing cell cycle activity marked by Ki67, and an increase in cardiomyocyte numbers compared to controls. [Sci Rep] Full Article

Cardiac Non-Myocyte Cells Show Enhanced Pharmacological Function Suggestive of Contractile Maturity in Stem Cell Derived Cardiomyocyte Microtissues
Researchers assessed the contribution of non-myocyte cells on the contractile function of co-cultured human embryonic stem cell derived cardiomyocytes in spheroid microtissue format. [Toxicol Sci]
Abstract | Full Article

Fibulin-2 Is Essential for Angiotensin II-Induced Myocardial Fibrosis Mediated by Transforming Growth Factor (TGF)-β
Researchers investigated the role of fibulin-2 in the development of myocardial hypertrophy and fibrosis induced by continuous pressor-dosage of angiotensin II (Ang II) infusion. To test whether fibulin-2 was sufficient for Ang II-induced TGF-β upregulation, isolated fibulin-2 null cardiac fibroblasts were treated with Ang II after transfecting with fibulin-2 expression vector or pretreating with recombinant fibulin-2 protein. [Lab Invest] Abstract

SKELETAL MUSCLE CELLS

NAD⁺ Repletion Improves Mitochondrial and Stem Cell Function and Enhances Life Span in Mice
Investigators demonstrated the importance of the amount of the oxidized form of cellular nicotinamide adenine dinucleotide (NAD⁺) and its impact on mitochondrial activity as a pivotal switch to modulate muscle stem cell senescence. [Science] Abstract | Press Release

β-Catenin Activation in Muscle Progenitor Cells Regulates Tissue Repair
The authors focus on the canonical Wnt signaling pathway and find that either conditional β-catenin disruption or activation in adult muscle stem cells results in perturbation of muscle regeneration. [Cell Rep]
Full Article | Graphical Abstract

Focal Adhesion Kinase and Paxillin Promote Migration and Adhesion to Fibronectin by Swine Skeletal Muscle Satellite Cells
Researchers compared the migration and adhesion of skeletal muscle satellite cells derived from two species of pig in vitro, and explored how focal adhesion kinase signaling modulates the two processes. [Oncotarget] Full Article

Lkb1 Deletion Upregulates Pax7 Expression through Activating Notch1 Signaling Pathway in Myoblasts
Scientists demonstrated that deletion of liver kinase b1 (Lkb1) upregulates paired-box transcription factor 7 (Pax7) expression in myoblasts and inhibits asymmetric divisions that generate differentiating progenies. [Int J Biochem Cell Biol] Abstract

Modeling Fibrosis Using Fibroblasts Isolated from Scarred Rat Vocal Folds
Scientists pursued detailed characterization of scar vocal fold fibroblasts (VFFs) obtained from surgically injured rat VF mucosae, compared with those obtained from experimentally naïve, age-matched tissue. Scar VFFs initially exhibited a myofibroblast phenotype characterized by increased proliferation, increased Col1a1 transcription and collagen, type I synthesis, increased Acta2 transcription and α-smooth muscle actin synthesis, and enhanced contractile function. [Lab Invest] Abstract

SMOOTH MUSCLE CELLS

MicroRNA-223 Attenuates Hypoxia-Induced Vascular Remodeling by Targeting RhoB/MLC2 in Pulmonary Arterial Smooth Muscle Cells
Researchers identified that miR-223 was significantly downregulated in chronically hypoxic mouse and rat lungs, as well as in pulmonary artery and pulmonary artery smooth muscle cells (PASMC) exposed to hypoxia. Knockdown of miR-223 increased PASMC proliferation. [Sci Rep] Full Article

Impaired Ca²⁺ Homeostasis and Decreased Orai1 Expression Modulates Arterial Hyporeactivity to Vasoconstrictors during Endotoxemia
Researchers hypothesized that SIRS/endotoxemia-associated hyporesponsiveness to vasoconstrictors is mediated by smaller increases in intracellular Ca²⁺ levels due to reduced signaling via the STIM/Orai. Cultured vascular smooth muscle cell treated with LPS resulted in increased TLR-4 expression, but Myd-88 and STIM-1 expression were not changed. [Inflammation] Abstract

Targeting BNIP3 in Inflammation-Mediated Heart Failure: A Novel Concept in Heart Failure Therapy
Investigators reviewed the changes in BCL-2/adenovirus E1B 19KD interacting protein 3 (BNIP3) protein expression levels during inflammatory response and postulated its role in inflammation-mediated heart failure. [Heart Fail Rev] Abstract

Visit our reviews page to see a complete list of reviews in the muscle cell research field.

Hemostemix Receives IRB Approval from the Houston Methodist Hospital Research Institute and the University of California Los Angeles
Hemostemix Inc. announced the approval of its lead product ACP-01 for critical limb ischemia for use in the company’s Phase II clinical trial by the Institutions Review Boards of the Houston Methodist Hospital Research Institute and University of California Los Angeles. [Hemostemix Inc.] Press Release

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Research Technologist – Myogenic and Progenitor Cell (STEMCELL Technologies Inc.)

PhD Positions – Molecular and Cellular Biology (IGBMC)

Research Technician – Myogenesis, Neurogenesis and Related Diseases (Fred Hutchinson Cancer Research Center)

Postdoctoral Fellow – Immuno-Metabolic Modulation of Skeletal Muscle Insulin Sensitivity (Karolinska Institutet)

PhD Position – Muscle Fiber Type Switch in Congenital Myopathies (King’s College London)

Postdoctoral Fellow – Pathogenesis of Heart and Vascular Injury (University of Alberta)

Postdoctoral Researcher – Stem Cell Biology Regenerative Medicine (NUI Galway)

Research Assistant – Skeletal Muscle Cell Biology (Nestlé)

Postdoctoral Positions – Tissue Repair/Inflammation (Institut Pasteur)

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