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Sample records for h9c2 rat myoblasts

  1. Endocytosis‒Mediated Invasion and Pathogenicity of Streptococcus agalactiae in Rat Cardiomyocyte (H9C2.

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    Sharma Pooja

    Full Text Available Streptococcus agalactiae infection causes high mortality in cardiovascular disease (CVD patients, especially in case of setting prosthetic valve during cardiac surgery. However, the pathogenesis mechanism of S. agalactiae associate with CVD has not been well studied. Here, we have demonstrated the pathogenicity of S. agalactiae in rat cardiomyocytes (H9C2. Interestingly, both live and dead cells of S. agalactiae were uptaken by H9C2 cells. To further dissect the process of S. agalactiae internalization, we chemically inhibited discrete parts of cellular uptake system in H9C2 cells using genistein, chlorpromazine, nocodazole and cytochalasin B. Chemical inhibition of microtubule and actin formation by nocodazole and cytochalasin B impaired S. agalactiae internalization into H9C2 cells. Consistently, reverse‒ transcription PCR (RT‒PCR and quantitative real time‒PCR (RT-qPCR analyses also detected higher levels of transcripts for cytoskeleton forming genes, Acta1 and Tubb5 in S. agalactiae‒infected H9C2 cells, suggesting the requirement of functional cytoskeleton in pathogenesis. Host survival assay demonstrated that S. agalactiae internalization induced cytotoxicity in H9C2 cells. S. agalactiae cells grown with benzyl penicillin reduced its ability to internalize and induce cytotoxicity in H9C2 cells, which could be attributed with the removal of surface lipoteichoic acid (LTA from S. agalactiae. Further, the LTA extracted from S. agalactiae also exhibited dose‒dependent cytotoxicity in H9C2 cells. Taken together, our data suggest that S. agalactiae cells internalized H9C2 cells through energy‒dependent endocytic processes and the LTA of S. agalactiae play major role in host cell internalization and cytotoxicity induction.

  2. Sulforaphane prevents doxorubicin-induced oxidative stress and cell death in rat H9c2 cells.

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    Li, Bo; Kim, Do Sung; Yadav, Raj Kumar; Kim, Hyung Ryong; Chae, Han Jung

    2015-07-01

    Sulforaphane, a natural isothiocyanate compound found in cruciferous vegetables, has been shown to exert cardioprotective effects during ischemic heart injury. However, the effects of sulforaphane on cardiotoxicity induced by doxorubicin are unknown. Thus, in the present study, H9c2 rat myoblasts were pre-treated with sulforaphane and its effects on cardiotoxicity were then examined. The results revealed that the pre-treatment of H9c2 rat myoblasts with sulforaphane decreased the apoptotic cell number (as shown by trypan blue exclusion assay) and the expression of pro-apoptotic proteins (Bax, caspase-3 and cytochrome c; as shown by western blot analysis and immunostaining), as well as the doxorubicin-induced increase in mitochondrial membrane potential (measured by JC-1 assay). Furthermore, sulforaphane increased the mRNA and protein expression of heme oxygenase-1 (HO-1, measured by RT-qPCR), which consequently reduced the levels of reactive oxygen species (ROS, measured using MitoSOX Red reagent) in the mitochondria which were induced by doxorubicin. The cardioprotective effects of sulforaphane were found to be mediated by the activation of the Kelch-like ECH-associated protein 1 (Keap1)/NF-E2-related factor-2 (Nrf2)/antioxidant-responsive element (ARE) pathway, which in turn mediates the induction of HO-1. Taken together, the findings of this study demonstrate that sulforaphane prevents doxorubicin-induced oxidative stress and cell death in H9c2 cells through the induction of HO-1 expression.

  3. Cardiac Shock Wave Therapy Attenuates H9c2 Myoblast Apoptosis by Activating the AKT Signal Pathway

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    Weiwei Yu

    2014-04-01

    Full Text Available Background: Previous studies have demonstrated that Cardiac Shock Wave Therapy (CSWT improves myocardial perfusion and cardiac function in a porcine model of chronic myocardial ischemia and also ameliorates myocardial ischemia in patients with severe coronary artery disease (CAD. Apoptosis plays a key role in ischemic myocardial pathogenesis. However, it remains unclear whether CSWT is beneficial for ischemia/hypoxia (I/H-induced myocardial cell apoptosis and by which mechanism CSWT could improve heart function. We put forward the hypothesis that CSWT might protect heart function during ischemia/hypoxia by decreasing apoptosis. Methods: We generated ischemia/hypoxia (I/H-induced apoptosis in the H9c2 myoblast cell line to examine the CSWT function and possible mechanisms. H9c2 cells were treated under hypoxic serum-starved conditions for 24 h and then treated with or without CSWT (500 shots, 0.06, 0.09, 0.12mJ/mm2. The apoptotic cell rate was determined by flow cytometry assay, cell viability was examined by the MTT assay, nuclear fragmentation was detected by Hoechst 33342 staining, and the mitochondrial-mediated intrinsic pathway of apoptosis was assessed by the expression of Bax and Bcl-2 protein and Caspase3 activation. Results: First, apoptosis could be induced by ischemia/hypoxia in H9c2 cells. Second, CSWT attenuates the cell death and decreases the H9c2 cell apoptosis rate induced by ischemia and hypoxia. Third, CSWT suppresses the expression of apoptosis molecules that regulate the intrinsic pathway of apoptosis in H9c2 cells. Fourth, CSWT increases the phosphorylation of AKT, which indicates the activation of the PI3K-AKT pathway. Conclusions: These results indicate that CSWT exerts a protective effect against I/H-induced cell death, potentially by preventing the activation of components of the mitochondrial-dependent intrinsic apoptotic pathway. We also demonstrate that the PI3K-Akt pathway may be involved in the CSWT effects on

  4. Pro-survival effect of Dock180 overexpression on rat-derived H9C2 cardiomyocytes.

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    Yan, An; Li, Gang; Zhang, Xu; Zhu, Bingbao; Linghu, Hua

    2013-01-14

    Integrin â1 subunit and its downstream molecule, focal adhesion kinase (FAK), have been demonstrated to be indispensible to the promotion of cell proliferation and survival and anti-apoptosis in cardiomyocytes via activation of their downstream pro-survival signaling molecule, AKT. As a component of the integrin pathway, Dock180 (dedicator of cytokinesis 1) protein is also thought to be involved in the promotion of cell proliferation and survival and anti-apoptosis in the H9C2 cardiomyocytes. Rat-derived H9C2 cardiomyocytes were transfected with pCXN2-flag-hDock180, a human Dock180 overexpression eukaryotic recombinant plasmid. The rat and human Dock180 mRNA and protein expression, apoptosis and cell proliferation and survival were analyzed in the H9C2 cardiomyocytes treated with either hypoxia/reoxygenation (H/R) or not, respectively. Human Dock180 mRNA overexpression could significantly increase the Dock180 protein expression in the H9C2 cardiomyocytes, no matter whether treated with H/R or not. Dock180 overexpression could promote the cell proliferation and survival and anti-apoptosis, and relieve the cell proliferative and survival inhibition and apoptosis induced by H/R in the H9C2 cardiomyocytes via activation of its downstream pro-survival signaling molecule AKT. Dock180 could act as a pro-survival molecule in H9C2 cardiomyocytes via activation of its downstream pro-survival signaling molecule, AKT.

  5. Norepinephrine-induced apoptotic and hypertrophic responses in H9c2 cardiac myoblasts are characterized by different repertoire of reactive oxygen species generation

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    Anita Thakur

    2015-08-01

    Full Text Available Despite recent advances, the role of ROS in mediating hypertrophic and apoptotic responses in cardiac myocytes elicited by norepinephrine (NE is rather poorly understood. We demonstrate through our experiments that H9c2 cardiac myoblasts treated with 2 µM NE (hypertrophic dose generate DCFH-DA positive ROS only for 2 h; while those treated with 100 µM NE (apoptotic dose sustains generation for 48 h, followed by apoptosis. Though the levels of DCFH fluorescence were comparable at early time points in the two treatment sets, its quenching by DPI, catalase and MnTmPyP suggested the existence of a different repertoire of ROS. Both doses of NE also induced moderate levels of H2O2 but with different kinetics. Sustained but intermittent generation of highly reactive species detectable by HPF was seen in both treatment sets but no peroxynitrite was generated in either conditions. Sustained generation of hydroxyl radicals with no appreciable differences were noticed in both treatment sets. Nevertheless, despite similar profile of ROS generation between the two conditions, extensive DNA damage as evident from the increase in 8-OH-dG content, formation of γ-H2AX and PARP cleavage was seen only in cells treated with the higher dose of NE. We therefore conclude that hypertrophic and apoptotic doses of NE generate distinct but comparable repertoire of ROS/RNS leading to two very distinct downstream responses.

  6. Antihistamines modulate the integrin signaling pathway in h9c2 rat cardiomyocytes: Possible association with cardiotoxicity.

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    Yun, J S; Kim, S Y

    2015-08-01

    The identification of biomarkers for toxicity prediction is crucial for drug development and safety evaluation. The selective and specific biomarkers for antihistamines-induced cardiotoxicity is not well identified yet. In order to evaluate the mechanism of the life-threatening effects caused by antihistamines, we used DNA microarrays to analyze genomic profiles in H9C2 rat cardiomyocytes that were treated with antihistamines. The gene expression profiles from drug-treated cells revealed changes in the integrin signaling pathway, suggesting that cardiac arrhythmias induced by antihistamine treatment may be mediated by changes in integrin-mediated signaling. It has been reported that integrin plays a role in QT prolongation that may induce cardiac arrhythmia. These results indicate that the integrin-mediated signaling pathway induced by antihistamines is involved in various biological mechanisms that lead to cardiac QT prolongation. Therefore, we suggest that genomic profiling of antihistamine-treated cardiomyocytes has the potential to reveal the mechanism of adverse drug reactions, and this signal pathway is applicable to prediction of in vitro cardiotoxicity induced by antihistamines as a biomarker candidate. © The Author(s) 2014.

  7. PAF exerts a direct apoptotic effect on the rat H9c2 cardiomyocytes in Ca2+-dependent manner.

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    Zhao, Dan; Chu, Wen-Feng; Wu, Ling; Li, Jing; Liu, Qing-Mei; Lu, Yan-Jie; Qiao, Guo-Fen; Wang, Zhi-Guo; Zhang, Zhi-Ren; Yang, Bao-Feng

    2010-08-06

    Previous studies suggested that platelet-activating factor (PAF) plays an important role in ischemic diseases. Apoptosis has been implicated in myocardial infarction-related cell death. The present study was designed to determine whether PAF could induce apoptosis in cardiac myocytes and the underlying mechanisms by which PAF causes apoptosis. H9c2 cardiac myocytes were used to investigate the effect of PAF on intracellular calcium concentration, cell viability and cell apoptosis. Signaling pathway of caspase-3, cytochrome c and MAPK (ERK, JNK, p38) was determined during the PAF induced apoptosis. First, our results showed that treatment of H9c2 cardiomyocytes with PAF (0.2 to 20 microM) caused apoptosis in these cells and the apoptotic process was suppressed by either BN52021 (an antagonist of PAF receptor) or BAPTA/AM (an intracellular Ca2+ chelator), suggesting an involvement of PAF and its receptor mediated calcium-dependent signaling. Second, we found that activity of p38-MAPK (mitogen-activated protein kinase) and caspase-3 was elevated in the cells treated with PAF, without altering activity of ERK and JNK, and that PAF-induced enhancement of caspase-3 activity was attenuated by application of either BAPTA/AM or SB203580 (p38 inhibitor). Furthermore, PAF-induced apoptosis and release of cytochrome c from mitochondria was blunted by SB203580, and PAF-induced enhancement of p38 activity was also attenuated by BAPTA/AM. Our data implicate that a PAF and its receptor in triggering apoptosis occurs in cultured H9c2 cardiac myocytes via a calcium-dependent p38 MAPK activated cytochrome c/caspase-3 apoptosis signaling pathway. Crown Copyright (c) 2009. Published by Elsevier Ireland Ltd. All rights reserved.

  8. C3G overexpression promotes the survival of rat-derived H9C2 cardiomyocytes by p-ERK1/2.

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    Zhang, Xu; Li, Gang; Zhang, Lei; Yang, Dongyan; Zhang, Zhisheng; Yan, An; Linghu, Hua

    2013-10-01

    Integrin β1 subunit and its downstream molecules, such as integrin-linked kinase and focal adhesion kinase, are imperative for promotion of cell proliferation, survival and anti-apoptosis in cardiomyocytes by activation of their downstream pro-survival signalling molecules, such as the phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2). As a component of the integrin pathway, C3G (Crk-SH3 domain guanine nucleotide exchange factor) protein may be involved in the promotion of cell proliferation and survival and anti-apoptosis in the H9C2 cardiomyocytes. Rat-derived H9C2 cardiomyocytes were transfected with pCXN2-flag-hC3G, a human C3G overexpression eukaryotic recombinant plasmid. Apoptosis, cell proliferation and survival were analysed in the H9C2 cardiomyocytes either treated with hypoxia/reoxygenation (H/R). Human C3G mRNA overexpression significantly elevated C3G protein expression in H9C2 cardiomyocytes whether treated with H/R or not. C3G overexpression promoted proliferation and survival and anti-apoptosis, and attenuated the proliferative and survival inhibition, and apoptosis induced by H/R by activation of its downstream pro-survival signalling molecule, p-ERK1/2. The results suggest that C3G acts as a pro-survival molecule in H9C2 cardiomyocytes by activation of p-ERK1/2. © 2013 International Federation for Cell Biology.

  9. 4-Guanidino-n-butyl syringate (Leonurine, SCM 198) protects H9c2 rat ventricular cells from hypoxia-induced apoptosis.

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    Liu, Xin-hua; Chen, Pei-fang; Pan, Li-long; Silva, Ranil De; Zhu, Yi-zhun

    2009-11-01

    In the present study, we examined the ability of a chemically synthesized compound based on the structure of leonurine, a phytochemical component of Herba leonuri, to protect H9c2 rat ventricular cells from apoptosis induced by hypoxia and serum deprivation, as a model of ischemia. The results revealed a concentration-dependent increase in cell viability associated with leonurine treatment, accompanied by a consistent decline in lactate dehydrogenase leakage into the culture medium. The fraction of annexin V-fluorescein isothiocyanate-positive cells was increased by hypoxia but reduced by leonurine. These changes were associated with increased expression of the antiapoptotic gene, Bcl-2, and reduced expression of the proapoptotic gene, Bax. Leonurine also reduced the cytosolic Ca overload induced by hypoxia. These results suggest that leonurine elicits potent cardioprotective effects in H9c2 cells, and these effects may be mediated by inhibition of intracellular Ca overload and apoptosis during hypoxia.

  10. Plant Natural Product Formononetin Protects Rat Cardiomyocyte H9c2 Cells against Oxygen Glucose Deprivation and Reoxygenation via Inhibiting ROS Formation and Promoting GSK-3β Phosphorylation

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    Yuanyuan Cheng

    2016-01-01

    Full Text Available The opening of mitochondrial permeability transition pore (mPTP is a major cause of cell death in ischemia reperfusion injury. Based on our pilot experiments, plant natural product formononetin enhanced the survival of rat cardiomyocyte H9c2 cells during oxygen glucose deprivation (OGD and reoxygenation. For mechanistic studies, we focused on two major cellular factors, namely, reactive oxygen species (ROS and glycogen synthase kinase 3β (GSK-3β, in the regulation of mPTP opening. We found that formononetin suppressed the formation of ROS and superoxide in a concentration-dependent manner. Formononetin also rescued OGD/reoxygenation-induced loss of mitochondrial membrane integrity. Further studies suggested that formononetin induced Akt activation and GSK-3β (Ser9 phosphorylation, thereby reducing GSK-3β activity towards mPTP opening. PI3K and PKC inhibitors abolished the effects of formononetin on mPTP opening and GSK-3β phosphorylation. Immunoprecipitation experiments further revealed that formononetin increased the binding of phosphor-GSK-3β to adenine nucleotide translocase (ANT while it disrupted the complex of ANT with cyclophilin D. Moreover, immunofluorescence revealed that phospho-GSK-3β (Ser9 was mainly deposited in the space between mitochondria and cell nucleus. Collectively, these results indicated that formononetin protected cardiomyocytes from OGD/reoxygenation injury via inhibiting ROS formation and promoting GSK-3β phosphorylation.

  11. Allicin protects rat cardiomyoblasts (H9c2 cells) from hydrogen peroxide-induced oxidative injury through inhibiting the generation of intracellular reactive oxygen species.

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    Chan, Jackie Yan-Yan; Tsui, Hei-Tung; Chung, Ivan Ying-Ming; Chan, Robbie Yat-Kan; Kwan, Yiu-Wa; Chan, Shun-Wan

    2014-11-01

    Oxidative stress is considered an important factor that promotes cell death in response to a variety of pathophysiological conditions. This study investigated the antioxidant properties of allicin, the principle ingredient of garlic, on preventing oxidative stress-induced injury. The antioxidant capacities of allicin were measured by using 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay and hydrogen peroxide (H(2)O(2))-induced cell damage on H9c2 cardiomyoblasts. Allicin (0.3-10 μM) pre-incubation could concentration-dependently attenuate the intracellular reactive oxygen species (ROS) increase induced by H(2)O(2) on H9c2 cells. It could also protect H9c2 cells against H(2)O(2)-induced cell damage. However, the DPPH free radical scavenging activity of allicin was shown to be low. Therefore, it is believed that the protective effect of allicin on H9c2 cells could inhibit intracellular ROS production instead of scavenging extracellular H(2)O(2) or free radicals. For the observed protective effect on H9c2 cells, allicin might also be effective in reducing free radical-induced myocardial cell death in ischemic condition.

  12. β-Sitosterol enhances cellular glutathione redox cycling by reactive oxygen species generated from mitochondrial respiration: protection against oxidant injury in H9c2 cells and rat hearts.

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    Wong, Hoi Shan; Chen, Na; Leong, Pou Kuan; Ko, Kam Ming

    2014-07-01

    Herba Cistanches (Cistanche deserticola Y. C. Ma) is a 'Yang-invigorating' tonic herb in Chinese medicine. Preliminary chemical analysis indicated that β-sitosterol (BS) is one of the chemical constituents in an active fraction of Herba Cistanches. To investigate whether BS is an active ingredient of Herba Cistanches, the effects of BS on H9c2 cells and rat hearts were examined. The results indicated that BS stimulated the mitochondrial ATP generation capacity in H9c2 cells, which was associated with the increased production of mitochondrial reactive oxygen species. BS also stimulated mitochondrial state 3 and state 4 respiration, with the resultant decrease in coupling efficiency. BS produced an up-regulation of cellular glutathione redox cycling and protected against hypoxia/reoxygenation-induced apoptosis in H9c2 cells. However, the protective effect of BS against myocardial ischemia/reperfusion injury was seen in female but not male rats ex vivo. The cardioprotection afforded by BS was likely mediated by an up-regulation of mitochondrial glutathione redox cycling in female rat hearts. In conclusion, the ensemble of results suggests that BS is an active ingredient of Herba Cistanches. The gender-dependent effect of BS on myocardial protection will further be investigated. Copyright © 2013 John Wiley & Sons, Ltd.

  13. Effects of pomegranate seed oil on oxidant/antioxidant balance in heart and kidney homogenates and mitochondria of diabetic rats and high glucose-treated H9c2 cell line.

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    Mollazadeh, Hamid; Boroushaki, Mohammad Taher; Soukhtanloo, Mohammad; Afshari, Amir Reza; Vahedi, Mohammad Mahdi

    2017-01-01

    Oxidative stress is a major cause of diabetes complications. The present study aimed to investigate the beneficial effects of Pomegranate Seed Oil (PSO) on diabetes-induced changes in oxidant/antioxidant balance of the kidney, heart and mitochondria from rats and H9c2 cell line. In these in vivo and in vitro studies, male rats were divided into four groups (twelve each): group 1 served as control, group 2-4 received a single dose of streptozotocin (60 mg/kg, i.p), groups 3 and 4 received PSO (0.36 and 0.72 mg/kg/daily, gavage), respectively. After three weeks, six rats of each group and one week later the remaining animals were anaesthetized and the hearts and kidneys were removed and homogenized. Mitochondrial fractions were separated and enzyme activities were measured in each sample. H9c2 cells were pretreated with high levels of glucose (35 mM), and then, incubated with PSO. Finally, cell viability test, reactive oxygen species production and lipid peroxidation were evaluated. Significant reduction in enzymes activity (Superoxide dismutase, Glutathione S-transferase and Paraoxonase 1), compensatory elevation in Glutathione Reductase, Glutathione Peroxidase and Catalase activity followed by reduction after one week and significant elevation in Oxidative Stress Index (OSI) were observed in diabetic group. PSO treatment resulted in a significant increase in enzymes activity and decreased OSI values compared to diabetic group in both tissue and mitochondrial fractions. PSO remarkably decreased glucose-induced toxicity, ROS level and lipid peroxidation in H9c2 cells. Results suggested that PSO has a protective effect against diabetes-induced alterations in oxidant/antioxidant balance in tissues, mitochondrial and H9c2 cell line.

  14. NADPH oxidase/ROS-dependent PYK2 activation is involved in TNF-α-induced matrix metalloproteinase-9 expression in rat heart-derived H9c2 cells

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    Yang, Chuen-Mao, E-mail: chuenmao@mail.cgu.edu.tw [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital at Keelung, Keelung, Taiwan (China); Lee, I-Ta [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Department of Anesthetics, Chang Gung Memorial Hospital at Linkou and College of Medicine, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China); Hsu, Ru-Chun; Chi, Pei-Ling; Hsiao, Li-Der [Department of Physiology and Pharmacology and Health Aging Research Center, Chang Gung University, Kwei-San, Tao-Yuan, Taiwan (China)

    2013-10-15

    TNF-α plays a mediator role in the pathogenesis of chronic heart failure contributing to cardiac remodeling and peripheral vascular disturbances. The implication of TNF-α in inflammatory responses has been shown to be mediated through up-regulation of matrix metalloproteinase-9 (MMP-9). However, the detailed mechanisms of TNF-α-induced MMP-9 expression in rat embryonic-heart derived H9c2 cells are largely not defined. We demonstrated that in H9c2 cells, TNF-α induced MMP-9 mRNA and protein expression associated with an increase in the secretion of pro-MMP-9. TNF-α-mediated responses were attenuated by pretreatment with the inhibitor of ROS (N-acetyl-L-cysteine, NAC), NADPH oxidase [apocynin (APO) or diphenyleneiodonium chloride (DPI)], MEK1/2 (U0126), p38 MAPK (SB202190), JNK1/2 (SP600125), NF-κB (Bay11-7082), or PYK2 (PF-431396) and transfection with siRNA of TNFR1, p47{sup phox}, p42, p38, JNK1, p65, or PYK2. Moreover, TNF-α markedly induced NADPH oxidase-derived ROS generation in these cells. TNF-α-enhanced p42/p44 MAPK, p38 MAPK, JNK1/2, and NF-κB (p65) phosphorylation and in vivo binding of p65 to the MMP-9 promoter were inhibited by U0126, SB202190, SP600125, NAC, DPI, or APO. In addition, TNF-α-mediated PYK2 phosphorylation was inhibited by NAC, DPI, or APO. PYK2 inhibition could reduce TNF-α-stimulated MAPKs and NF-κB activation. Thus, in H9c2 cells, we are the first to show that TNF-α-induced MMP-9 expression is mediated through a TNFR1/NADPH oxidase/ROS/PYK2/MAPKs/NF-κB cascade. We demonstrated that NADPH oxidase-derived ROS generation is involved in TNF-α-induced PYK2 activation in these cells. Understanding the regulation of MMP-9 expression and NADPH oxidase activation by TNF-α on H9c2 cells may provide potential therapeutic targets of chronic heart failure. - Highlights: • TNF-α induces MMP-9 secretion and expression via a TNFR1-dependent pathway. • TNF-α induces ROS/PYK2-dependent MMP-9 expression in H9c2 cells. • TNF

  15. Feasibility of dual reporter gene in rat myoblast cell line using human sodium iodide symporter (hNIS) and enhanced green fluorescent protein (EGFP) gene

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    Lee, Yong Jin; Lee, You La; Ahn, Sohn Joo; Choi, Chang Ik; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae [School of Medicine, Kyungpook National University, Daegu (Korea, Republic of)

    2007-07-01

    To develop a non-invasive combined imaging method of gamma camera and optical imaging to assess rat myoblast cell line, H9c2, we constructed retrovirus containing hNIS and EGFP gene, and transfected to rat myoblast cell and monitored hNIS and EGFP expression. Rat myoblast cell line, H9C2, was transfected with hNIS and EGFP gene using retrovirus (H9C2-NG). The expression of hNIS and EGFP gene was determined by RT-PCR and fluorescence microscopy, respectively. The uptake and efflux of I-125 were measured in the transfected and wild type cell lines. Each cell line was injected to 4 flank sites (H9c2: 1X107 or 2X107, H9C2-NG: 1X107 or 2X107) in nude mouse. Scintigraphic image was performed at 3h, 1 day after H9C2 and H9C2-NG cell inoculation. We performed gamma camera and animal PET imaging to evaluate NIS expression. Also, GFP image obtained using optical imaging system. The expression of hNIS and EGFP gene was confirmed by RT-PCR. In iodide uptake, H9C2-NG cells accumulated 274.52.2 pmol/ mg protein at 30 min. But wild type cell line did not uptake iodide. In fluorescent microscopy, H9C2-NG cells were highly fluorescent than that of H9C2 cells. In iodide efflux study, 50% of radioactivity flowed out during the first 10min. Scintigraphy showed increased uptake of Tc-99m in H9c2-NG than in H9C2 for 1 day. Also, H9C2-NG cells showed high signal-to-background fluorescent spots in animal body. In this study, NIS and EGFP reporter gene were successfully transfected by a retrovirus in myoblast cell line, and the transfected cell can be easily visualized in vivo. These results suggest that NIS and EGFP gene has an excellent feasibility as a reporter gene, and it can be used to monitor cell trafficking for monitoring.

  16. Microfluidic system for monitoring of cardiac (H9C2) cell proliferation

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    Kobuszewska, A.; Cwik, P.; Jastrzebska, E.; Brzozka, Z.; Chudy, M.; Renaud, P.; Dybko, A.

    2017-05-01

    The paper presents the application of electrical impedance spectroscopy (EIS) analysis for investigation of cardiac cell (H9C2 - rat cardiomyoblast) proliferation after verapamil hydrochloride exposure. For this purpose, two different PDMS/glass microsystems with circular microchamber and longitudinal microchannel integrated with Pt/Al electrodes were used. The microchambers were fabricated in PDMS using photolithography and replica moulding techniques. Pt/Al electrodes were fabricated on a 4-inch glass substrate using Physical Vapor Deposition (PVD). Solution of verapamil hydrochloride was continuously introduced into the microsystems with H9C2 cell culture (a flow rate of 1 μl/min) for 72 h. The impedance spectra were recorded from 100 Hz to 1 MHz. We confirmed that impedance spectroscopy can be used for non-invasive, label-free and real-time analysis of cardiac cells proliferation based on cells dielectric properties and biological structure.

  17. Sulforaphane protects H9c2 cardiomyocytes from angiotensin II-induced hypertrophy.

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    Wu, Q-Q; Zong, J; Gao, L; Dai, J; Yang, Z; Xu, M; Fang, Y; Ma, Z-G; Tang, Q-Z

    2014-05-01

    Cardiac hypertrophy is an adaptive process of the heart in response to various stimuli, but sustained cardiac hypertrophy will finally lead to heart failure. Sulforaphane-extracted from cruciferous vegetables of the genus Brassica such as broccoli, brussels sprouts, and cabbage-has been evaluated for its anticarcinogenic and antioxidant effects. To investigate the effect of sulforaphane on angiotensin II (Ang II)-induced cardiac hypertrophy in vitro. Embryonic rat heart-derived H9c2 cells were co-incubated with sulforaphane and Ang II. The cell surface area and mRNA levels of hypertrophic markers were measured to clarify the effect of sulforaphane on cardiac hypertrophy. The underlying mechanism was further investigated by detecting the activation of Akt and NF-κB signaling pathways. We found that H9c2 cells pretreated with sulforaphane were protected from Ang II-induced hypertrophy. The increasing mRNA levels of ANP, BNP, and β-MHC in Ang II-stimulated cells were also down-regulated after sulforaphane treatment. Moreover, sulforaphane repressed the Ang II-induced phosphorylation of Akt, GSK3β, mTOR, eIF4e, as well as of IκBα and NF-κB. Based on our results, sulforaphane attenuates Ang II-induced hypertrophy of H9c2 cardiomyocytes mediated by the inhibition of intracellular signaling pathways including Akt and NF-κB.

  18. Early NADPH oxidase-2 activation is crucial in phenylephrine-induced hypertrophy of H9c2 cells.

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    Hahn, Nynke E; Musters, René J P; Fritz, Jan M; Pagano, Patrick J; Vonk, Alexander B A; Paulus, Walter J; van Rossum, Albert C; Meischl, Christof; Niessen, Hans W M; Krijnen, Paul A J

    2014-09-01

    Reactive oxygen species (ROS) produced by different NADPH oxidases (NOX) play a role in cardiomyocyte hypertrophy induced by different stimuli, such as angiotensin II and pressure overload. However, the role of the specific NOX isoforms in phenylephrine (PE)-induced cardiomyocyte hypertrophy is unknown. Therefore we aimed to determine the involvement of the NOX isoforms NOX1, NOX2 and NOX4 in PE-induced cardiomyocyte hypertrophy. Hereto rat neonatal cardiomyoblasts (H9c2 cells) were incubated with 100 μM PE to induce hypertrophy after 24 and 48h as determined via cell and nuclear size measurements using digital imaging microscopy, electron microscopy and an automated cell counter. Digital-imaging microscopy further revealed that in contrast to NOX1 and NOX4, NOX2 expression increased significantly up to 4h after PE stimulation, coinciding and co-localizing with ROS production in the cytoplasm as well as the nucleus. Furthermore, inhibition of NOX-mediated ROS production with apocynin, diphenylene iodonium (DPI) or NOX2 docking sequence (Nox2ds)-tat peptide during these first 4h of PE stimulation significantly inhibited PE-induced hypertrophy of H9c2 cells, both after 24 and 48h of PE stimulation. These data show that early NOX2-mediated ROS production is crucial in PE-induced hypertrophy of H9c2 cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Sodium Tanshinone IIA Sulfonate Prevents Radiation-Induced Toxicity in H9c2 Cardiomyocytes

    National Research Council Canada - National Science Library

    Wenjing Zhang; Yi Li; Rui Li; Yaya Wang; Mengwen Zhu; Bowen Wang; Yanling Li; Dongyun Li; Ping Xie; Bin Liu

    2017-01-01

    .... It was found that the cell viability of H9c2 cells exposed to X-ray radiation was significantly decreased in a dose-dependent manner and was associated with cell cycle arrest at the G0/G1 phase as well as apoptosis...

  20. Impaired ALDH2 activity decreases the mitochondrial respiration in H9C2 cardiomyocytes.

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    Mali, Vishal R; Deshpande, Mandar; Pan, Guodong; Thandavarayan, Rajarajan A; Palaniyandi, Suresh S

    2016-02-01

    Reactive oxygen species (ROS)-mediated reactive aldehydes induce cellular stress. In cardiovascular diseases such as ischemia-reperfusion injury, lipid-peroxidation derived reactive aldehydes such as 4-hydroxy-2-nonenal (4HNE) are known to contribute to the pathogenesis. 4HNE is involved in ROS formation, abnormal calcium handling and more importantly defective mitochondrial respiration. Aldehyde dehydrogenase (ALDH) superfamily contains NAD(P)(+)-dependent isozymes which can detoxify endogenous and exogenous aldehydes into non-toxic carboxylic acids. Therefore we hypothesize that 4HNE afflicts mitochondrial respiration and leads to cell death by impairing ALDH2 activity in cultured H9C2 cardiomyocyte cell lines. H9C2 cardiomyocytes were treated with 25, 50 and 75 μM 4HNE and its vehicle, ethanol as well as 25, 50 and 75 μM disulfiram (DSF), an inhibitor of ALDH2 and its vehicle (DMSO) for 4 h. 4HNE significantly decreased ALDH2 activity, ALDH2 protein levels, mitochondrial respiration and mitochondrial respiratory reserve capacity, and increased 4HNE adduct formation and cell death in cultured H9C2 cardiomyocytes. ALDH2 inhibition by DSF and ALDH2 siRNA attenuated ALDH2 activity besides reducing ALDH2 levels, mitochondrial respiration and mitochondrial respiratory reserve capacity and increased cell death. Our results indicate that ALDH2 impairment can lead to poor mitochondrial respiration and increased cell death in cultured H9C2 cardiomyocytes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Mitochondrial reactive oxygen species production mediates ursolic acid-induced mitochondrial uncoupling and glutathione redox cycling, with protection against oxidant injury in H9c2 cells.

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    Chen, Jihang; Wong, Hoi Shan; Ko, Kam Ming

    2015-02-01

    Ursolic acid (UA), a natural pentacyclic triterpenoid carboxylic acid, is a ubiquitous compound widely distributed in many plants, fruits and medicinal herbs worldwide. A previous study in our laboratory has shown that UA can increase the mitochondrial ATP generation capacity (ATP-GC) and a glutathione-dependent antioxidant response, thereby protecting against oxidant injury in H9c2 cells in vitro and rat hearts ex vivo. However, the mechanism underlying the cellular protective effects induced by UA remains largely unknown. The present study has shown that pre-incubation with UA produces a transient increase in the mitochondrial membrane potential in H9c2 cells, which was accompanied by increases in mitochondrial reactive oxygen species (ROS) production. Studies using an antioxidant (dimethylthiourea) indicated that the suppression of mitochondrial ROS completely abrogated the UA-induced enhancement of mitochondrial uncoupling and glutathione reductase (GR)-mediated glutathione redox cycling, as well as protection against menadione cytotoxicity in H9c2 cells. Co-incubation with specific inhibitors of uncoupling proteins and GR almost completely prevented the cytoprotection afforded by UA against menadione-induced cytotoxicity in H9c2 cells. The results obtained so far suggest that UA-induced mitochondrial ROS production can elicit mitochondrial uncoupling and glutathione-dependent antioxidant responses, which offer cytoprotection against oxidant injury in H9c2 cells.

  2. p21WAF1 and hypoxia/reoxygenation-induced premature senescence of H9c2 cardiomyocytes

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    Ming-Yong Cao

    2011-10-01

    Full Text Available We have previously reported on hypoxia/reoxygenation-induced premature senescence in neonatal rat cardiomyocytes. In this research, we investigated the effects of p21WAF1 (p21 in hypoxia/reoxygenation-induced senescence, using H9c2 cells. A plasmid overexpressing wild type p21WAF1 and a plasmid expressing small hairpin RNA (shRNA targeting p21WAF1 were constructed, and transfected into H9c2 cells to control the p21 expression. Hypoxia/reoxygenation conditions were 1% O2 and 5% CO2, balancing the incubator chamber with N2 for 6 h (hypoxia 6 h, then 21% oxygen for 8 h (reoxygenation 8 h. Cell cycle was examined using flow cytometry. Senescence was assessed using β-galactosidase staining. The expression of p53, p21, p16INK4a, and cyclin D1 was assayed using Western blotting. At hypoxia 6 h, cells overexpressing p21 had a larger G1 distribution, stronger β-galactosidase activity, and lower cyclin D1 expression compared to control cells, while the opposite results and higher p53 expression were obtained in p21-knockdown cells. At reoxygenation 8 h, p21-silenced cells had a smaller percentage of G1 cells, weaker β-galactosidase activity and lower 16INK4a expression, and higher cyclin D1 expression, but the overexpression group showed no difference. Taken together, this data implies that p21WAF1 is important for the hypoxia phase, but not the reoxygenation phase, in the H9c2 senescence process. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 445–451

  3. The Metabolic Effects of Traditional Chinese Medication Qiliqiangxin on H9C2 Cardiomyocytes

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    Shenghui Lin

    2015-11-01

    Full Text Available Background/Aims: A traditional Chinese medicine, Qiliqiangxin (QLQX has been identified to perform protective effects on myocardium energy metabolism in mice with acute myocardial infarction, though the effects of QLQX on myocardial mitochondrial biogenesis under physiological condition is still largely elusive. Methods: H9C2 cells were treated with different concentrations of QLQX (0.25, 0.5, and 1.0 µg/mL from 6 to 48 hours. Oxidative metabolism and glycolysis were measured by oxygen consumption and extracellular acidification with XF96 analyzer (SeaHorse. Mitochondrial content and ultrastructure were assessed by Mitotracker staining, confocal microscopy, flow cytometry, and transmission electron microscopy. Mitochondrial biogenesis-related genes were measured by qRT-PCR and Western blot. Results: H9C2 cells treated with QLQX exhibited increased glycolysis at earlier time points (6, 12, and 24 hours, while QLQX could enhance oxidative metabolism and mitochondrial uncoupling in H9C2 cells with longer duration of treatment (48 hours. QLQX also increased mitochondrial content and mitochondrial biogenesis-related gene expression levels, including 16sRNA, SSBP1, TWINKLE, TOP1MT and PLOG, with an activation of peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α and its downstream effectors. Silencing PGC-1α could abolish the increased mitochondrial content in H9C2 cells treated with QLQX. Conclusion: Our study is the first to document enhanced metabolism in cardiomyocytes treated with QLQX, which is linked to increased mitochondrial content and mitochondrial biogenesis via activation of PGC-1α.

  4. Sodium Ferulate Prevents Daunorubicin - Induced Apoptosis in H9c2 Cells via Inhibition of the ERKs Pathway

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    Zhi-Juan Wu

    2015-07-01

    Full Text Available Background: Daunorubicin (DNR-induced cardiotoxicity, which is closely associated with cardiomyocyte apoptosis, limits the drug's clinical application. The activation of the extracellular regulated protein kinases (ERKs pathway is responsible for the pro-apoptosis effect of DNR Sodium ferulate (SF has recently been found to attenuate both DNR-induced cardiotoxicity and mitochondrial apoptosis in juvenile rats. Nonetheless, the precise mechanism underlying SF-induced cardio-protection remains unclear. Methods: The DNR-injured H9c2 cell model was prepared by incubating the cells in 1 µM DNR for 24 h. Amounts of 15.6, 31.3 or 62.5 µM SF were simultaneously added to the cells. The effect of SF on the cytotoxic and apoptotic parameters of the cells was studied by monitoring apoptosis regulation via the ERKs pathway. Results: SF attenuated DNR-induced cell death (particularly apoptotic death, cTnI and β-tubulin degradation, and cellular morphological changes. SF reduced mitochondrial membrane potential depolarization, cytochrome c leakage, and caspase-9 and caspase-3 activation. SF also decreased ERK1/2, phospho-ERK1/2, p53 and Bax expression and increased Bcl-2 expression. These effects were similar to the results observed when using the pharmacological ERKs phosphorylation inhibitor, AZD6244. Conclusion: We determined that SF protects H9c2 cells from DNR-induced apoptosis through a mechanism that involves the interruption of the ERKs signaling pathway.

  5. Differential behaviour of epicardial adipose tissue-secretomes with high and low orosomucoid levels from patients with cardiovascular disease in H9C2 cells.

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    Lage, Ricardo; Moscoso, Isabel; Fernández-Trasancos, Ángel; Cebro, María; Couselo, Marinela; Fandiño-Vaquero, Rubén; Bravo, Susana B; Sierra, Juan; González-Juanatey, José Ramón; Eiras, Sonia

    2015-11-15

    Epicardial adipose tissue releases orosomucoid (ORM), an acute phase protein with multiple modulatory and protective properties. We aimed to identify the effect of EAT-supernatants according to their ORM levels on H9C2 cells. H9C2 were cultured with EAT-secretomes or ORM protein itself on a Real-Time Cell Analyser. Secretome proteins identification was performed by LC-mass spectrometry according to their ORM levels. Two of them were validated by ELISA in EAT-supernatants from 42 patients. ORM effect on H9C2 and neonatal rat cardiomyocytes apoptosis under hypoxia with or without fatty acid treatment was determined by Annexin-V flow cytometry measurement. Caspase-3 expression levels were determined by western blot in H9C2. Our results showed a differential effect of EAT-secretomes according their ORM levels. Although additional secreted proteins can contribute to their beneficial effects, ORM reduced hypoxia-induced apoptosis through caspase-3 inhibition. Our data showed the cardioprotective role of ORM and suggest that its quantification on EAT secretomes might help us to find new secreted factors with a cardioprotective role. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. BNC Protects H9c2 Cardiomyoblasts from H2O2-Induced Oxidative Injury through ERK1/2 Signaling Pathway

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    Fangbo Zhang

    2013-01-01

    Full Text Available Buchang naoxintong capsule (BNC is a traditional Chinese medicine approved for the treatment of cerebrovascular and cardiovascular diseases. However, little is known about the specific protective function or mechanism by which BNC protects against myocardial injury. This research was designed to investigate the cardioprotective effects of BNC in vitro model of hydrogen peroxide (H2O2-induced H9c2 rat cardiomyoblasts. BNC intestinal absorption liquid was used in this study instead of drug-containing serum or extracting solution. Our study revealed that BNC preconditioning enhanced antioxidant function by increasing the activities of total-antioxygen capacity, total-superoxide dismutase, and catalase and by decreasing the production of reactive oxygen species and malondialdehyde. BNC preconditioning also activated extracellular signal-regulated kinases (ERK1/2 and inhibited apoptosis-related proteins such as poly ADP-ribose polymerase (PARP and caspase-3. Additionally, preincubation with BNC reduced intracellular Ca2+ concentration, improved mitochondrial membrane potential, and decreased the apoptosis rate of H9c2 cells in a dose-dependent manner. These data demonstrated that BNC protects H9c2 cardiomyoblasts from H2O2-induced oxidative injury by increasing antioxidant abilities, activating ERK1/2, and blocking Ca2+-dependent and mitochondria-mediated apoptosis. Based on our results, the potency of BNC for protecting H9c2 cells from oxidative damage is comparable to that of trimetazidine.

  7. Antiapoptotic effect of novel compound from Herba leonuri - leonurine (SCM-198): a mechanism through inhibition of mitochondria dysfunction in H9c2 cells.

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    Liu, Xin Hua; Pan, Li Long; Gong, Qi Hai; Zhu, Yi Zhun

    2010-12-01

    Apoptosis of cardiomyocytes induced by oxidative stress play a critical role in cardiac dysfunction associated with ventricular remodeling and heart failure. We recently reported that leonurine attenuated hypoxia-induced cardiomyocyte damage. In this study, we investigated the mechanism of leonurine (originally from Herba leonuri but we synthesized it chemically it as also called SCM-198) (H₂O₂)-induced rat embryonic heart-derived H9c2 cells from apoptosis. Exposing H9c2 cells to H₂O₂ significantly decreased cell viability, and this was attenuated by pretreatment with leonurine for 4 h in a concentration-dependent manner. Meanwhile, leonurine was found to reduce intracellular reactive oxygen species (ROS) generation in H₂O₂-stimulated cell. Moreover, H9c2 cells stimulated by H₂O₂ was accompanied with apparent apoptotic characteristics, including fragmentation of DNA, apoptotic body formation, release of cytochrome c, translocation of Bax to mitochondria, loss of mitochondrial membrane potential (ΔΨ(m)) and activation of caspase 3. Furthermore, H₂O₂ also induced rapid and significant phosphorylation of the c-Jun-N-terminal kinase 1/2 (JNK1/2), which was inhibited SP600125 (a JNK1/2 inhibitor). All of these events were attenuated by leonurine pretreatment. Taken together, these results demonstrated that leonurine could protect H9c2 cells from H₂O₂-induced apoptosis via modulation of mitochondrial dysfunction associated with blocking the activation of JNK1/2.

  8. Glibenclamide Mimics Metabolic Effects of Metformin in H9c2 Cells

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    Barbara Salani

    2017-09-01

    Full Text Available Background: Sulfonylureas, such as glibenclamide, are antidiabetic drugs that stimulate beta-cell insulin secretion by binding to the sulfonylureas receptors (SURs of adenosine triphosphate-sensitive potassium channels (KATP. Glibenclamide may be also cardiotoxic, this effect being ascribed to interference with the protective function of cardiac KATP channels for which glibenclamide has high affinity. Prompted by recent evidence that glibenclamide impairs energy metabolism of renal cells, we investigated whether this drug also affects the metabolism of cardiac cells. Methods: The cardiomyoblast cell line H9c2 was treated for 24 h with glibenclamide or metformin, a known inhibitor of the mitochondrial respiratory chain. Cell viability was evaluated by sulforodhamine B assay. ATP and AMP were measured according to the enzyme coupling method and oxygen consumption by using an amperometric electrode, while Fo-F1 ATP synthase activity assay was evaluated by chemiluminescent method. Protein expression was measured by western blot. Results: Glibenclamide deregulated energy balance of H9c2 cardiomyoblasts in a way similar to that of metformin. It inhibited mitochondrial complexes I, II and III with ensuing impairment of oxygen consumption and ATP synthase activity, ATP depletion and increased AMPK phosphorylation. Furthermore, glibenclamide disrupted mitochondrial subcellular organization. The perturbation of mitochondrial energy balance was associated with enhanced anaerobic glycolysis, with increased activity of phosphofructo kinase, pyruvate kinase and lactic dehydrogenase. Interestingly, some additive effects of glibenclamide and metformin were observed. Conclusions: Glibenclamide deeply alters cell metabolism in cardiac cells by impairing mitochondrial organization and function. This may further explain the risk of cardiovascular events associated with the use of this drug, alone or in combination with metformin.

  9. Discovering Antioxidant Molecules in the Archaea Domain: Peroxiredoxin Bcp1 from Sulfolobus solfataricus Protects H9c2 Cardiomyoblasts from Oxidative Stress

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    Carmen Sarcinelli

    2016-01-01

    Full Text Available Peroxiredoxins (Prxs are ubiquitous thiol peroxidases that are involved in the reduction of peroxides. It has been reported that prokaryotic Prxs generally show greater structural robustness than their eukaryotic counterparts, making them less prone to inactivation by overoxidation. This difference has inspired the search for new antioxidants from prokaryotic sources that can be used as possible therapeutic biodrugs. Bacterioferritin comigratory proteins (Bcps of the hyperthermophilic archaeon Sulfolobus solfataricus that belong to the Prx family have recently been characterized. One of these proteins, Bcp1, was chosen to determine its antioxidant effects in H9c2 rat cardiomyoblast cells. Bcp1 activity was measured in vitro under physiological temperature and pH conditions that are typical of mammalian cells; the yeast thioredoxin reductase (yTrxR/thioredoxin (yTrx reducing system was used to evaluate enzyme activity. A TAT-Bcp1 fusion protein was constructed to allow its internalization and verify the effect of Bcp1 on H9c2 rat cardiomyoblasts subjected to oxidative stress. The results reveal that TAT-Bcp1 is not cytotoxic and inhibits H2O2-induced apoptosis in H9c2 cells by reducing the H2O2 content inside these cells.

  10. Methyl donor deficiency in H9c2 cardiomyoblasts induces ER stress as an important part of the proteome response.

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    Martinez, Emilie; Deval, Christiane; Jousse, Céline; Mazur, Andrzej; Brachet, Patrick; Comte, Blandine

    2015-02-01

    Deficiency of methyl donors (MDs, folate, vitamin B12, and choline) causes increased plasma level of Hcy, a risk factor for cardiovascular diseases. Previously, we showed that maternal MD deprivation altered the cardiac proteome of rat pups. To better understand its impact on cardiac cells, we exposed rat H9c2 cardiomyoblasts to selectively a synthetic folate- or MD-deficient (FD or MDD) medium. We found that a 4-day exposure to the FD medium, unlike the MDD one, did not cause an abnormal extracellular release of Hcy relatively to similar exposure to the control complete (C) medium. Comparative analyses of the proteomes of FD, MDD, and C cells identified 7 and 6 proteins up- or downregulated by either deficiency, respectively. Most proteins were found interrelated in a single network dealing with "post-translational modification, protein folding and cell death/survival" (FD cells) or "DNA replication/recombination/repair and cell morphology/compromise" (MDD cells). Both deficiencies altered the protein and mRNA levels of the chaperones α-crystallin B, protein disulfide-isomerase A4, and prohibitin. This was concurrent with rapid induction of several key genes of the ER stress response, notably gadd153/chop, and increased expression of the E3 ubiquitin ligases, Hrd1, and MAFbx. In conclusion, the effects of folate and MD deficiencies on the cardiomyoblast proteome display some dissimilarities possibly related to different cellular production of Hcy. In both cases activation of the ER stress could occur in response to accumulation of ubiquitinated misfolded proteins. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Myricitrin Attenuates High Glucose-Induced Apoptosis through Activating Akt-Nrf2 Signaling in H9c2 Cardiomyocytes

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    Bin Zhang

    2016-07-01

    Full Text Available Hyperglycemia, as well as diabetes mellitus, has been shown to trigger cardiac cell apoptosis. We have previously demonstrated that myricitrin prevents endothelial cell apoptosis. However, whether myricitrin can attenuate H9c2 cell apoptosis remains unknown. In this study, we established an experiment model in H9c2 cells exposed to high glucose. We tested the hypothesis that myricitrin may inhibit high glucose (HG-induced cardiac cell apoptosis as determined by TUNEL staining. Furthermore, myricitrin promoted antioxidative enzyme production, suppressed high glucose-induced reactive oxygen species (ROS production and decreased mitochondrial membrane potential (MMP in H9c2 cells. This agent significantly inhibited apoptotic protein expression, activated Akt and facilitated the transcription of NF-E2-related factor 2 (Nrf2-mediated protein (heme oxygenase-1 (HO-1 and quinone oxidoreductase 1 (NQO-1 expression as determined by Western blotting. Significantly, an Akt inhibitor (LY294002 or HO-1 inhibitor (ZnPP not only inhibited myricitrin-induced HO-1/NQO-1 upregulation but also alleviated its anti-apoptotic effects. In summary, these observations demonstrate that myricitrin activates Nrf2-mediated anti-oxidant signaling and attenuates H9c2 cell apoptosis induced by high glucose via activation of Akt signaling.

  12. Disruption of dopamine D1/D2 receptor complex is involved in the function of haloperidol in cardiac H9c2 cells.

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    Lencesova, L; Szadvari, I; Babula, P; Kubickova, J; Chovancova, B; Lopusna, K; Rezuchova, I; Novakova, Z; Krizanova, O; Novakova, M

    2017-12-15

    Haloperidol is an antipsychotic agent and acts as dopamine D2 receptor (D2R) antagonist, as a prototypical ligand of sigma1 receptors (Sig1R) and it increases expression of type 1 IP 3 receptors (IP 3 R1). However, precise mechanism of haloperidol action on cardiomyocytes through dopaminergic signaling was not described yet. This study investigated a role of dopamine receptors in haloperidol-induced increase in IP 3 R1 and Sig1R, and compared physiological effect of melperone and haloperidol on basic heart parameters in rats. We used differentiated NG-108 cells and H9c2 cells. Gene expression, Western blot and immunofluorescence were used to evaluate haloperidol-induced differences; proximity ligation assay (PLA) and immunoprecipitation to determine interactions of D1/D2 receptors. To evaluate cardiac parameters, Wistar albino male rats were used. We have shown that antagonism of D2R with either haloperidol or melperone results in upregulation of both, IP 3 R1 and Sig1R, which is associated with increased D2R, but reduced D1R expression. Immunofluorescence, immunoprecipitation and PLA support formation of heteromeric D1/D2 complexes in H9c2 cells. Treatment with haloperidol (but not melperone) caused decrease in systolic and diastolic blood pressure and significant increase in heart rate. Because D1R/D2R complexes can engage Gq-like signaling in other experimental systems, these results are consistent with the possibility that disruption of D1R/D2R complex in H9c2 cells might cause a decrease in IP 3 R1 activity, which in turn may account for the increase expression of IP 3 R and Sig1R. D2R is probably not responsible for changes in cardiac parameters, since melperone did not have any effect. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Polyphenol-rich apple (Malus domestica L.) peel extract attenuates arsenic trioxide induced cardiotoxicity in H9c2 cells via its antioxidant activity.

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    Vineetha, Vadavanath Prabhakaran; Girija, Seetharaman; Soumya, Rema Sreenivasan; Raghu, Kozhiparambil Gopalan

    2014-03-01

    Evidences suggest that apple peel has a wide range of polyphenols having antioxidant activity and its consumption has been linked with improved health benefits. Arsenic trioxide (ATO) is a very effective drug for the treatment of acute promyelocytic leukemia (APL) but it leads to cardiotoxicity mediated through alterations in various cardiac ion channels and by increasing the intracellular calcium level and reactive oxygen species (ROS). The aim of the present investigation was to study the effect of methanolic extract of apple peel (APME) and aqueous extract of apple peel (APAE) on ATO (5 μM) induced toxicity in the H9c2 cardiac myoblast cell line. We estimated the cellular status of innate antioxidant enzymes, level of ROS, mitochondrial superoxide, glutathione and intracellular calcium with ATO and apple peel extracts. Prior to the cell line based study, we had evaluated the antioxidant potential of apple peel extract by 1,1-diphenyl-2-picrylhydrazyl (DPPH), total reducing power (TRP), superoxide anion and hydroxyl radical scavenging activity, in addition to quantifying total phenolic and flavonoid content. Both the extracts showed considerable antioxidant activity in cell-free chemical assays. In addition, both APME and APAE prevented the alteration in antioxidant status induced by ATO in H9c2 cells. Significant differential alterations had been observed in the activity of lactate dehydrogenase, superoxide dismutase, catalase, glutathione, glutathione peroxidase, thioredoxin reductase, xanthine oxidase, calcium overload and caspase 3 activity with ATO. The overall result revealed the protective property of polyphenol-rich apple peel extract against ATO induced cardiac toxicity via its antioxidant activity.

  14. Thrombopoietin protects H9C2 cells from excessive autophagy and apoptosis in doxorubicin-induced cardiotoxicity

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    Wang, Han; Wang, Hua; Liang, En-Yu; Zhou, Li-Xia; Dong, Zhan-Ling; Liang, Ping; Weng, Qi-Fang; Yang, Mo

    2018-01-01

    Cardiac toxicity has been the major concern when using doxorubicin (DOX) in cancer therapy. Thrombopoietin (TPO) protects cardiac cells from DOX-induced cell damage; however, its molecular mechanism remains exclusive. The anti-autophagic and anti-apoptotic effects of TPO upon DOX treatment were studied in the cardiac H9C2 cell line, with bafilomycin A1 treatment as a positive control for autophagy inhibition. Cell viability was measured by Cell Counting Kit-8 assay in different treatment groups. The mRNA and/or protein levels of apoptotic markers and autophagy-associated factors were detected. The mean number of microtubule-associated protein 1A/1B-light chain 3 (LC3) puncta per cell was quantified to indicate autophagosomes and autolysosomes, of which the ones co-stained with lysosomal-associated membrane protein 1 were considered as autolysosomes. DOX treatment (5 µg/ml, 24 h) significantly impaired H9C2 cell viability compared with the control, while TPO pretreatment (10 ng/ml, 36 h) improved cell viability upon DOX treatment. DOX exposure markedly increased LC3 puncta in H9C2 cells, and TPO pretreatment reduced the number of autophagosomes, but showed no significant inhibitory effect on autolysosome formation. The autophagy inhibition by TPO upon DOX treatment was confirmed according to protein quantification of LC3-II and nucleoporin 62. TPO also suppressed autophagy-promoting protein Beclin-1, and elevated the anti-autophagic factors GATA-binding protein-4 and B cell lymphoma-2. Furthermore, TPO reduced DOX-induced apoptosis in H9C2 cells, as reflected by the amount changes of caspase-3. Taken together, these results revealed that TPO has a protective role in H9C2 cells from DOX-induced autophagy as well as apoptosis, and indicated that TPO may act as a cardioprotective drug in DOX-treated patients. PMID:29403560

  15. Acetylcholine Attenuates Hypoxia/ Reoxygenation-Induced Mitochondrial and Cytosolic ROS Formation in H9c2 Cells via M2 Acetylcholine Receptor

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    Yi Miao

    2013-02-01

    Full Text Available Background: The anti-infammatory and cardioprotective effect of acetylcholine (ACh has been reported; nevertheless, whether and how ACh exhibits an antioxidant property against ischemia/reperfusion (I/R-induced oxidative stress remains obscure. Methods: In the present study, H9c2 rat cardiomyocytes were exposed to hypoxia/reoxygenation (H/R to mimic I/R injury. We estimated intracellular different sources of reactive oxygen species (ROS by measuring mitochondrial ROS (mtROS, mitochondrial DNA (mtDNA copy number, xanthine oxidase (XO and NADPH oxidase (NOX activity and expression of rac 1. Cell injury was determined by lactate dehydrogenase (LDH release and cleaved caspase-3 expression. The siRNA transfection was performed to knockdown of M2 acetylcholine receptor (M2 AChR expression. Results: 12-h hypoxia followed by 2-h reoxygenation resulted in an abrupt burst of ROS in H9c2 cells. Administration of ACh reduced the levels of ROS in a concentration-dependent manner. Compared to the H/R group, ACh decreased mtROS, recovered mtDNA copy number, diminished XO and NOX activity, rac 1 expression as well as cell injury. Co- treatment with atropine rather than hexamethonium abolished the antioxidant and cardioprotective effect of ACh. Moreover, knockdown of M2 AChR by siRNA showed the similar trends as atropine co-treatment group. Conclusions: ACh inhibits mitochondria-, XO- and NOX-derived ROS production thus protecting H9c2 cells against H/R-induced oxidative stress, and these benefcial effects are mainly mediated by M2 AChR. Our findings suggested that increasing ACh release could be a potential therapeutic strategy for treatment and prevention of I/R injury.

  16. Chlorogenic acid analogues from Gynura nepalensis protect H9c2 cardiomyoblasts against H2O2-induced apoptosis.

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    Yu, Bang-Wei; Li, Jin-Long; Guo, Bin-Bin; Fan, Hui-Min; Zhao, Wei-Min; Wang, He-Yao

    2016-11-01

    Chlorogenic acid has shown protective effect on cardiomyocytes against oxidative stress-induced damage. Herein, we evaluated nine caffeoylquinic acid analogues (1-9) isolated from the leaves of Gynura nepalensis for their protective effect against H2O2-induced H9c2 cardiomyoblast damage and explored the underlying mechanisms. H9c2 cardiomyoblasts were exposed to H2O2 (0.3 mmol/L) for 3 h, and cell viability was detected with MTT assay. Hoechst 33342 staining was performed to evaluate cell apoptosis. MMPs (mitochondrial membrane potentials) were measured using a JC-1 assay kit, and ROS (reactive oxygen species) generation was measured using CM-H2 DCFDA. The expression levels of relevant proteins were detected using Western blot analysis. Exposure to H2O2 markedly decreased the viability of H9c2 cells and catalase activity, and increased LDH release and intracellular ROS production; accompanied by a loss of MMP and increased apoptotic rate. Among the 9 chlorogenic acid analogues as well as the positive control drug epigallocatechin gallate (EGCG) tested, compound 6 (3,5-dicaffeoylquinic acid ethyl ester) was the most effective in protecting H9c2 cells from H2O2-induced cell death. Pretreatment with compound 6 (1.56-100 μmol/L) dose-dependently alleviated all the H2O2-induced detrimental effects. Moreover, exposure to H2O2 significantly increased the levels of Bax, p53, cleaved caspase-8, and cleaved caspase-9, and decreased the level of Bcl-2, resulting in cell apoptosis. Exposure to H2O2 also significantly increased the phosphorylation of p38, JNK and ERK in the H9c2 cells. Pretreatment with compound 6 (12.5 and 25 μmol/L) dose-dependently inhibited the H2O2-induced increase in the level of cleaved caspase-9 but not of cleaved caspase-8. It also dose-dependently suppressed the H2O2-induced phosphorylation of JNK and ERK but not that of p38. Compound 6 isolated from the leaves of Gynura nepalensis potently protects H9c2 cardiomyoblasts against H2O2-induced

  17. p21WAF1 and hypoxia/reoxygenation-induced premature senescence of H9c2 cardiomyocytes

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    Dan Wang

    2011-10-01

    Full Text Available We have previously reported on hypoxia/reoxygenation-induced premature senescence in neonatalrat cardiomyocytes. In this research, we investigated the effects of p21WAF1 (p21 in hypoxia/reoxygenation-inducedsenescence, using H9c2 cells. A plasmid overexpressing wild type p21WAF1 and a plasmid expressing smallhairpin RNA (shRNA targeting p21WAF1 were constructed, and transfected into H9c2 cells to control the p21expression. Hypoxia/reoxygenation conditions were 1% O2 and 5% CO2, balancing the incubator chamber withN2 for 6 h (hypoxia 6 h, then 21% oxygen for 8 h (reoxygenation 8 h. Cell cycle was examined using flowcytometry. Senescence was assessed using b-galactosidase staining. The expression of p53, p21, p16INK4a, andcyclin D1 was assayed using Western blotting. At hypoxia 6 h, cells overexpressing p21 had a larger G1 distribution,stronger b-galactosidase activity, and lower cyclin D1 expression compared to control cells, while the oppositeresults and higher p53 expression were obtained in p21-knockdown cells. At reoxygenation 8 h, p21-silencedcells had a smaller percentage of G1 cells, weaker b-galactosidase activity and lower 16INK4a expression, andhigher cyclin D1 expression, but the overexpression group showed no difference. Taken together, this data impliesthat p21WAF1 is important for the hypoxia phase, but not the reoxygenation phase, in the H9c2 senescenceprocess. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 445–451

  18. Clematichinenoside (AR Attenuates Hypoxia/Reoxygenation-Induced H9c2 Cardiomyocyte Apoptosis via a Mitochondria-Mediated Signaling Pathway

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    Haiyan Ding

    2016-05-01

    Full Text Available Mitochondria-mediated cardiomyocyte apoptosis is involved in myocardial ischemia/reperfusion (MI/R injury. Clematichinenoside (AR is a triterpenoid saponin isolated from the roots of Clematis chinensis with antioxidant and anti-inflammatory cardioprotection effects against MI/R injury, yet the anti-apoptotic effect and underlying mechanisms of AR in MI/R injury remain unclear. We hypothesize that AR may improve mitochondrial function to inhibit MI/R-induced cardiomyocyte apoptosis. In this study, we replicated an in vitro H9c2 cardiomyocyte MI/R model by hypoxia/reoxygenation (H/R treatment. The viability of H9c2 cardiomyocytes was determined by MTT assay; apoptosis was evaluated by flow cytometry and TUNEL experiments; mitochondrial permeability transition pore (mPTP opening was analyzed by a calcein-cobalt quenching method; and mitochondrial membrane potential (ΔΨm was detected by JC-1. Moreover, we used western blots to determine the mitochondrial cytochrome c translocation to cytosolic and the expression of caspase-3, Bcl-2, and Bax proteins. These results showed that the application of AR decreased the ratio of apoptosis and the extent of mPTP opening, but increased ΔΨm. AR also inhibited H/R-induced release of mitochondrial cytochrome c and decreased the expression of the caspase-3, Bax proteins. Conversely, it remarkably increased the expression of Bcl-2 protein. Taken together, these results revealed that AR protects H9c2 cardiomyocytes against H/R-induced apoptosis through mitochondrial-mediated apoptotic signaling pathway.

  19. Hydrogen sulfide protects against apoptosis under oxidative stress through SIRT1 pathway in H9c2 cardiomyocytes.

    Science.gov (United States)

    Wu, Dan; Hu, Qingxun; Liu, Xinhua; Pan, Lilong; Xiong, Qinghui; Zhu, Yi Zhun

    2015-04-30

    Oxidative stress plays a great role in the pathogenesis of heart failure (HF). Oxidative stress results in apoptosis, which can cause the damage of cardiomyocytes. Hydrogen sulfide (H2S), the third gasotransmitter, is a good reactive oxygen species (ROS) scavenger, which has protective effect against HF. Sirtuin-1 (SIRT1) is a highly conserved nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase that plays a critical role in promoting cell survival under oxidative stress. The purpose of this article is to investigate the interaction between H2S and SIRT1 under oxidative stress in H9c2 cardiomyocytes. Oxidative stress was induced by hydrogen peroxide (H2O2). Treatment with NaSH (25-100 µmol/L) dose-dependently increased the cell viability and improved the cell apoptosis induced by H2O2 in H9c2 cardiomyocytes. The protective effect of NaSH against the apoptosis could be attenuated by SIRT1 inhibitor Ex 527 (10 µmol/L). Treatment with NaSH (100 µmol/L) could increase the expression of SIRT1 in time dependent manner, which decreased by different concentration of H2O2. NaSH (100 µmol/L) increased the cellular ATP level and the expression of ATPase. These effects were attenuated by Ex 527 (10 µmol/L). After NaSH (100 µmol/L) treatment, the decrease in ROS production and the enhancement in SOD, GPx and GST expression were observed. Ex 527 (10 µmol/L) reversed these effects. In conclusion, for the first time, this article can identify antioxidative effects of H2S under oxidative stress through SIRT1 pathway in H9c2 cardiomyocytes. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Protective effect of p-coumaric acid against doxorubicin induced toxicity in H9c2 cardiomyoblast cell lines

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    Sunitha M. Chacko

    2015-01-01

    Full Text Available Doxorubicin (Dox has been used for more than four decades to treat cancer, particularly solid tumours and haematological malignancies. However, the administration of this drug is a matter of concern in the clinical community, since Dox therapy is commonly associated with dose-dependent cardiotoxicity. Attempts at alleviating drug generated cardiac damage using naturally occurring compounds with radical scavenging property are a promising area of research. p-Coumaric acid (pCA is one such compound which has significant antiradical scavenging effect. This study aims to investigate the effect of pre and co-administration of pCA on mitigating or preventing Dox induced cardiotoxicity in vitro using H9c2 cardiomyoblast cell lines. Addition of pCA and Dox were performed for both treatment and control sets on H9c2 cells. Sulphorhodamine B assay was used to study the cytotoxic effect of pCA and Dox. The effect of the drug on cell morphology, cell viability and nuclear damage was studied using AO/EB and DAPI staining. ROS production was studied using DCFH-DA staining. Mitochondrial membrane potential and intracellular calcium levels were assessed by rhodamine 123 and Fura 2AM staining. pCA showed strong ABTS cation radical scavenging activity and FRAP activity in a dose dependent manner. The results showed that Dox has significant cytotoxic effect in a dose dependent manner while pCA, even at higher concentrations did not display any significant cytotoxicity on H9c2 cells. Both pre treatment and co- administration of pCA reduced the drug induced toxic effects on cell morphology and enhanced the number of viable cells in comparison to the Dox treated cells as evident from the AO/EB and DAPI staining images. The Dox induced ROS production was found to be significantly reduced in pCA pre-treated and co-administered cells. Dox induced changes in mitochondrial membrane potential and intracellular calcium levels were remarkably improved following pre and co

  1. Protective Effect of Hibiscus Sabdariffa on Doxorubicin-induced Cytotoxicity in H9c2 Cardiomyoblast Cells.

    Science.gov (United States)

    Hosseini, Azar; Bakhtiari, Elham; Mousavi, Seyed Hadi

    2017-01-01

    Doxorubicin (DOX) is an effective anticancer drug. But its clinical application is limited, because DOX induces apoptosis in cardiomyocytes and it leads to permanent degenerative cardiomyopathy and heart failure. Recent trainings showed that Hibiscus sabdariffa exhibit pharmacological actions such as potent antioxidant. So, in this study we explored the protective effect of H. sabdariffa extract on doxorubicin-induced cytotoxicity in H9c2 cells. Cell viability was quantified by MTT assay. Apoptotic cells were determined using PI staining of DNA fragmentation by flowcytometry (sub-G1 peak). Cells were cultured with 5 μM DOX for 24 h to create the cell damage. H9c2 cells were pretreated with different concentrations (7.81-500 μg/mL) of H. sabdariffa extract (HSE) for 2 h before DOX treatment in all trials. Pretreatment with HSE increased cell viability at concentration of 31.25-500 μg/mL. Compared to control cells, apoptosis was induced in DOX treated cells after 24 h, (sabdariffa could exert the cardioprotective effects on DOX-induced toxicity partly by antiapoptotic activity.

  2. Microvesicles derived from hypoxia/reoxygenation-treated human umbilical vein endothelial cells promote apoptosis and oxidative stress in H9c2 cardiomyocytes

    National Research Council Canada - National Science Library

    Zhang, Qi; Shang, Man; Zhang, Mengxiao; Wang, Yao; Chen, Yan; Wu, Yanna; Liu, Minglin; Song, Junqiu; Liu, Yanxia

    2016-01-01

    .... H9c2 cardiomyocytes were then incubated with 10, 30, 60 μg/mL H/R-EMVs for 6 h. We found that H9c2 cells treated by H/R-EMVs exhibited reduced cell viability, increased cell apoptosis and reactive oxygen species...

  3. Odanacatib Inhibits Resistin-induced Hypertrophic H9c2 Cardiomyoblast Cells Through LKB1/AMPK Pathway

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    Xian Zheng

    2017-08-01

    Full Text Available ABSTRACT Odanacatib (ODN is a selective inhibitor of cathepsin K. The cysteine protease cathepsin K has been implicated in cardiac hypertrophy. Resistine is an adipokine which is identified to promote cardiac hypertrophy. Here, we hypothesize that ODN mitigates resistin-induced myocyte hypertrophy. Cell surface area and protein synthesis were measured after treatment with resistin and ODN in H9c2 cells. The expression of cardiomyocyte hypertrophy marker BNP and β-MHC was detected by RT-qPCR. The expression and phosphorylation of AMPK and LKB1 were analyzed with Western blot. Resistin could significantly increase cardiomyocyte cell surface area, protein synthesis, and embryonic gene BNP and β-MHC expression, inhibit phosphorylation of AMPK and LKB1. ODN could significantly reverse the effects of resistin. Collectively, our data suggest that ODN can inhibit cardiomyocyte hypertrophy induced by resistin and the underlying mechanism may be involved in LKB1/AMPK pathway.

  4. The protective effect of lycopene on hypoxia/reoxygenation-induced endoplasmic reticulum stress in H9C2 cardiomyocytes.

    Science.gov (United States)

    Gao, Yang; Jia, Pengyu; Shu, WenQi; Jia, Dalin

    2016-03-05

    Nowadays, drugs protecting ischemia/reperfusion (I/R) myocardium become more suitable for clinic. It has been confirmed lycopene has various protections, but lacking the observation of its effect on endoplasmic reticulum stress (ERS)-mediated apoptosis caused by hypoxia/reoxygenation (H/R). This study aims to clarify the protective effect of lycopene on ERS induced by H/R in H9C2 cardiomyocytes. Detect the survival rate, lactic dehydrogenase (LDH) activity, apoptosis ratio, glucose-regulated proteins 78 (GRP78), C/EBP homologous protein (CHOP), c-Jun-N-terminal protein Kinase (JNK) and Caspase-12 mRNA and protein expression and phosphorylation of JNK (p-JNK) protein expression. LDH activity, apoptosis ratio and GRP78 protein expression increase in the H/R group, reduced by lycopene. The survival rate reduces in the H/R and thapsigargin (TG) groups; lycopene and 4-phenyl butyric acid (4-PBA) can improve it caused by H/R, lycopene also can improve it caused by TG. The apoptosis ratio, the expression of GRP78, CHOP and Caspase-12 mRNA and protein and p-JNK protein increase in the H/R and TG groups, weaken in the lycopene+H/R, 4-PBA+H/R and lycopene+TG groups. There is no obvious change in the expression of JNK mRNA or protein. Hence, our results provide the evidence that 10 μM lycopene plays an obviously protective effect on H/R H9C2 cardiomyocytes, realized through reducing ERS and apoptosis. The possible mechanism may be related to CHOP, p-JNK and Caspase-12 pathways. Copyright © 2016. Published by Elsevier B.V.

  5. TanshinoneIIA and cryptotanshinone protect against hypoxia-induced mitochondrial apoptosis in H9c2 cells.

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    Hyou-Ju Jin

    Full Text Available Mitochondrial apoptosis pathway is an important target of cardioprotective signalling. Tanshinones, a group of major bioactive compounds isolated from Salvia miltiorrhiza, have been reported with actions against inflammation, oxidative stress, and myocardial ischemia reperfusion injury. However, the actions of these compounds on the chronic hypoxia-related mitochondrial apoptosis pathway have not been investigated. In this study, we examined the effects and molecular mechanisms of two major tanshonones, tanshinone IIA (TIIA and cryptotanshinone (CT on hypoxia induced apoptosis in H9c2 cells. Cultured H9c2 cells were treated with TIIA and CT (0.3 and 3 μΜ 2 hr before and during an 8 hr hypoxic period. Chronic hypoxia caused a significant increase in hypoxia inducible factor 1α expression and the cell late apoptosis rate, which was accompanied with an increase in caspase 3 activity, cytochrome c release, mitochondria membrane potential and expression of pro-apoptosis proteins (Bax and Bak. TIIA and CT (0.3 and 3 μΜ, in concentrations without affecting the cell viability, significantly inhibited the late apoptosis and the changes of caspase 3 activity, cytochrome c release, and mitochondria membrane potential induced by chronic hypoxia. These compounds also suppressed the overexpression of Bax and reduced the ratio of Bax/Bcl-2. The results indicate that TIIA and CT protect against chronic hypoxia induced cell apoptosis by regulating the mitochondrial apoptosis signaling pathway, involving inhibitions of mitochondria hyperpolarization, cytochrome c release and caspase 3 activity, and balancing anti- and pro-apoptotic proteins in Bcl-2 family proteins.

  6. Knockdown of CkrL by shRNA deteriorates hypoxia/reoxygenation-induced H9C2 cardiomyocyte apoptosis and survival inhibition Via Bax and downregulation of P-Erk1/2.

    Science.gov (United States)

    Zhang, Zhi-Sheng; Yang, Dong-Yan; Fu, Yan-Bo; Zhang, Lei; Zhao, Qian-Ping; Li, Gang

    2015-03-01

    Integrin β1 subunit and its downstream molecule integrin-linked kinase and focal adhesion kinase have been confirmed to be essential to cell survival and inhibition of apoptosis and hypoxia/reoxygenation (H/R)-induced injuries in cardiomyocytes. However, it is still unclear whether CrkL [v-crk avian sarcoma virus CT-10 oncogene homolog (Crk)-like], which acts also as a component of the integrin pathway, could also affect H/R-induced injuries in the cardiomyocytes. The rat-derived H9C2 cardiomyocytes were infected with a CrkL small hairpin RNA interference recombinant lentivirus, which knockdowns the endogenous CrkL expression in the cardiomyocytes. Apoptosis, cell proliferation and survival were examined in the H9C2 cardiomyocytes treated with either H/R or not. Results showed that knockdown of CrkL could significantly increase apoptosis and inhibition of the cell proliferation and survival and deteriorate the previously mentioned injuries induced by H/R. In contrast, overexpression of human CrkL could relieve the exacerbation of the previously mentioned injuries induced by CrkL knockdown in the H9C2 cardiomyocytes via regulation of Bax and extracellular signal-regulated kinase1/2 (p-ERK1/2). In conclusion, these results confirmed that knockdown of CrkL could deteriorate H/R-induced apoptosis and cell survival inhibition in rat-derived H9C2 cardiomyocytes via Bax and downregulation of p-ERK1/2. It implies that CrkL could mitigate H/R-induced injuries in the cardiomyocytes. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Salidroside protects against hydrogen peroxide-induced injury in cardiac H9c2 cells via PI3K-Akt dependent pathway.

    Science.gov (United States)

    Zhu, Ye; Shi, Ya-Ping; Wu, Dan; Ji, Ya-Jing; Wang, Xue; Chen, Hua-Li; Wu, Si-Si; Huang, De-Jia; Jiang, Wei

    2011-10-01

    Oxidative stress induces serious tissue injury in cardiovascular diseases. Salidroside, with its strong antioxidative and cytoprotective actions, is of particular interest in the development of antioxidative therapies for oxidative injury in cardiac diseases. We examined the pharmacological effects of salidroside on H9c2 rat cardiomyoblast cells under conditions of oxidative stress induced by hydrogen peroxide (H2O2) challenge. Salidroside attenuated H2O2-impaired cell viability in a concentration-dependent manner, and effectively inhibited cellular malondialdehyde production, lethal sarcolemmal disruption, cell necrosis, and apoptosis induced by H2O2 insult. Salidroside significantly augmented Akt phosphorylation at Serine 473 in the absence or presence of H2O2 stimulation; wortmannin, a specific inhibitor of PI3K, abrogated salidroside protection. Salidroside increased the intracellular mRNA expression and activities of catalase and Mn-superoxide dismutases in a PI3K-dependent manner. Our results indicated that salidroside protected cardiomyocytes against oxidative injury through activating the PI3K/Akt pathway and increasing the expression and activities of endogenous PI3K dependent antioxidant enzymes.

  8. Salidroside inhibits oxygen glucose deprivation (OGD)/re-oxygenation-induced H9c2 cell necrosis through activating of Akt-Nrf2 signaling.

    Science.gov (United States)

    Zheng, Koulong; Sheng, Zhenqiang; Li, Yefei; Lu, Huihe

    2014-08-15

    Oxygen glucose deprivation (OGD)/re-oxygenation has been applied to cultured cardiomyocytes to create a cellular model of ischemic heart damage. In the current study, we explored the potential role of salidroside against OGD/re-oxygenation-induced damage in H9c2 cardiomyocytes, and studied the underlying mechanisms. We found that OGD/re-oxygenation primarily induced necrosis in H9c2 cells, which was inhibited by salidroside. Salidroside suppressed OGD/re-oxygenation-induced reactive oxygen species (ROS) production, p53 mitochondrial translocation and cyclophilin D (Cyp-D) association as well as mitochondrial membrane potential (MMP) decrease in H9c2 cells. Meanwhile, salidroside activated Akt and promoted transcription of NF-E2-related factor 2 (Nrf2)-regulated genes (heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO-1)). Significantly, Nrf2 shRNA knockdown or Akt inhibitors (LY 294002 and wortmannin) not only prevented salidroside-induced HO-1/NQO-1 transcription, but also alleviated salidroside-mediated cytoprotective effect against OGD/re-oxygenation in H9c2 cells. These observations suggest that salidroside activates Nrf2-regulated anti-oxidant signaling, and protects against OGD/re-oxygenation-induced H9c2 cell necrosis via activation of Akt signaling. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Smad4 mediated BMP2 signal is essential for the regulation of GATA4 and Nkx2.5 by affecting the histone H3 acetylation in H9c2 cells

    Energy Technology Data Exchange (ETDEWEB)

    Si, Lina; Shi, Jin; Gao, Wenqun [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Zheng, Min [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Liu, Lingjuan; Zhu, Jing [Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China); Tian, Jie, E-mail: jietian@cqmu.edu.cn [Heart Centre, Children’s Hospital of Chongqing Medical University, 136 Zhongshan 2nd Road, Yu Zhong District, Chongqing 400014 (China)

    2014-07-18

    Highlights: • BMP2 can upregulated cardiac related gene GATA4, Nkx2.5, MEF2c and Tbx5. • Inhibition of Smad4 decreased BMP2-induced hyperacetylation of histone H3. • Inhibition of Smad4 diminished BMP2-induced overexpression of GATA4 and Nkx2.5. • Inhibition of Smad4 decreased hyperacetylated H3 in the promoter of GATA4 and Nkx2.5. • Smad4 is essential for BMP2 induced hyperacetylated histone H3. - Abstract: BMP2 signaling pathway plays critical roles during heart development, Smad4 encodes the only common Smad protein in mammals, which is a pivotal nuclear mediator. Our previous studies showed that BMP2 enhanced the expression of cardiac transcription factors in part by increasing histone H3 acetylation. In the present study, we tested the hypothesis that Smad4 mediated BMP2 signaling pathway is essential for the expression of cardiac core transcription factors by affecting the histone H3 acetylation. We successfully constructed a lentivirus-mediated short hairpin RNA interference vector targeting Smad4 (Lv-Smad4) in rat H9c2 embryonic cardiac myocytes (H9c2 cells) and demonstrated that it suppressed the expression of the Smad4 gene. Cultured H9c2 cells were transfected with recombinant adenoviruses expressing human BMP2 (AdBMP2) with or without Lv-Smad4. Quantitative real-time RT-PCR analysis showed that knocking down of Smad4 substantially inhibited both AdBMP2-induced and basal expression levels of cardiac transcription factors GATA4 and Nkx2.5, but not MEF2c and Tbx5. Similarly, chromatin immunoprecipitation (ChIP) analysis showed that knocking down of Smad4 inhibited both AdBMP2-induced and basal histone H3 acetylation levels in the promoter regions of GATA4 and Nkx2.5, but not of Tbx5 and MEF2c. In addition, Lv-Smad4 selectively suppressed AdBMP2-induced expression of HAT p300, but not of HAT GCN5 in H9c2 cells. The data indicated that inhibition of Smad4 diminished both AdBMP2 induced and basal histone acetylation levels in the promoter regions of

  10. Eosinophil Cationic Protein Shows Survival Effect on H9c2 Cardiac Myoblast Cells with Enhanced Phosphorylation of ERK and Akt/GSK-3β under Oxidative Stress

    OpenAIRE

    Mikamo, Shoko; Nakatsuka, Mikiya

    2015-01-01

    To assess the knowledge and attitudes of pregnant Japanese women regarding non-invasive prenatal testing (NIPT). Between March and June 2013, 557 pregnant women in the Hyogo and Hiroshima Prefectures were surveyed using an anonymous, self-completed questionnaire. A total of 91.9オ respondents (512/557) stated that they “agree” or “conditionally agree” with NIPT implementation in Japan. Approximately 28.5オ of respondents stated that they knew that the accuracy of a positive NIPT result can be a...

  11. Globular adiponectin protects H9c2 cells from palmitate-induced apoptosis via Akt and ERK1/2 signaling pathways

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    Wei Chuan

    2012-10-01

    Full Text Available Abstract Background Cardiomyocytes apoptosis is an important contributor to myocardial dysfunction and heart failure. Adiponectin has cardioprotective effects, potential mechanisms behind it are not clear in cardiomyocytes. The purpose of the study was to investigate whether adiponectin can block palmitate-induced apoptosis and the underlying biochemical mechanism in H9c2 cells. Methods H9c2 cells were treated with palmitate presence or absence of 2.5 μg/mL globular adiponectin. The effect on the cell viability of H9c2 cells was evaluated using MTT assay, and cell apoptosis was determined by Hoechst 33342 staining. Protein expression was measured using the western blot method. Results Our results showed that the palmitate treatment induced apoptosis in H9c2 cells, which was associated with increasing the level of cleaved caspase-3 and cleaved PARP. Meanwhile, palmitate-induced apoptosis increased the protein level of p-ERK1/2, and decreased the protein level of p-Akt significantly. However, levels of both of these proteins were restored to the normal when pretreated with adiponectin, and followed with the decrease of cleaved caspase-3 and cleaved PARP. In line with these results, the protective effect of adiponectin can be blocked by PI3K/Akt inhibitor LY294002, and palmitate-induced apoptosis can be attenuated by ERK1/2 inhibitor U0126. Conclusions Taken together, the present study demonstrated that adiponectin protects H9c2 cells from palmitate-induced apoptosis via PI3K/Akt and ERK1/2 signaling pathways. Our results reveal a link between adiponectin and cardiomyocytes apoptosis, suggesting that adioponectin may be a promising therapeutic for the treatment of lipotoxicity cardiomyopathy.

  12. S-Propargyl-cysteine (SPRC) attenuated lipopolysaccharide-induced inflammatory response in H9c2 cells involved in a hydrogen sulfide-dependent mechanism.

    Science.gov (United States)

    Pan, Li-Long; Liu, Xin-Hua; Gong, Qi-Hai; Zhu, Yi-Zhun

    2011-06-01

    The present study attempts to investigate the effects of S-propargyl-cysteine (SPRC), a sulfur-containing amino acid, on lipopolysaccharide (LPS)-induced inflammatory response in H9c2 cardiac myocytes. We found that SPRC prevented nuclear factor-κB (NF-κB) activation assessed by NF-κB p65 phosphorylation and IκBα degradation, suppressed LPS-induced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and intracellular reactive oxygen species (ROS) production. Furthermore, incubation of H9c2 cells with SPRC induced phosphorylation of Akt in a time- and concentration-dependent manner. In addition, SPRC attenuated LPS-induced mRNA and protein expression of tumor necrosis factor-α (TNF-α), and mRNA expression of intercellular adhesion molecule-1 (ICAM-1) and inducible nitric oxide synthase (iNOS). The effects of SPRC were abolished by cystathionine γ-lyase [CSE-an enzyme that synthesizes hydrogen sulfide (H(2)S)] inhibitor, DL: -propargylglycine (PAG), SPRC-induced Akt phosphorylation and TNF-α release was also abolished by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Furthermore, SPRC also increased LPS-induced down-regulation expression of CSE and H(2)S level in H9c2 cells. PAG abolished SPRC-induced up-regulation of H(2)S level. Therefore, we concluded that SPRC produced an anti-inflammatory effect in LPS-stimulated H9c2 cells partly through the CSE/H(2)S pathway by impairing IκBα/NF-κB signaling and by activating PI3K/Akt signaling pathway.

  13. Protective effect of Boerhaavia diffusa L. against mitochondrial dysfunction in angiotensin II induced hypertrophy in H9c2 cardiomyoblast cells.

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    Ayyappan Prathapan

    Full Text Available Mitochondrial dysfunction plays a critical role in the development of cardiac hypertrophy and heart failure. So mitochondria are emerging as one of the important druggable targets in the management of cardiac hypertrophy and other associated complications. In the present study, effects of ethanolic extract of Boerhaavia diffusa (BDE, a green leafy vegetable against mitochondrial dysfunction in angiotensin II (Ang II induced hypertrophy in H9c2 cardiomyoblasts was evaluated. H9c2 cells challenged with Ang II exhibited pathological hypertrophic responses and mitochondrial dysfunction which was evident from increment in cell volume (49.09±1.13%, protein content (55.17±1.19%, LDH leakage (58.74±1.87%, increased intracellular ROS production (26.25±0.91%, mitochondrial superoxide generation (65.06±2.27%, alteration in mitochondrial transmembrane potential (ΔΨm, opening of mitochondrial permeability transition pore (mPTP and mitochondrial swelling. In addition, activities of mitochondrial respiratory chain complexes (I-IV, aconitase, NADPH oxidase, thioredoxin reductase, oxygen consumption rate and calcium homeostasis were evaluated. Treatment with BDE significantly prevented the generation of intracellular ROS and mitochondrial superoxide radicals and protected the mitochondria by preventing dissipation of ΔΨm, opening of mPTP, mitochondrial swelling and enhanced the activities of respiratory chain complexes and oxygen consumption rate in H9c2 cells. Activities of aconitase and thioredoxin reductase which was lowered (33.77±0.68% & 45.81±0.71% respectively due to hypertrophy, were increased in BDE treated cells (P≤0.05. Moreover, BDE also reduced the intracellular calcium overload in Ang II treated cells. Overall results revealed the protective effects of B. diffusa against mitochondrial dysfunction in hypertrophy in H9c2 cells and the present findings may shed new light on the therapeutic potential of B. diffusa in addition to its

  14. Rosmarinic Acid suppressed high glucose-induced apoptosis in H9c2 cells by ameliorating the mitochondrial function and activating STAT3.

    Science.gov (United States)

    Diao, Jiayu; Wei, Jin; Yan, Rui; Liu, Xin; Li, Qing; Lin, Lin; Zhu, Yanhe; Li, Hong

    2016-09-02

    Mitochondrial injury characterized by intracellular reactive oxygen species (ROS) accumulation plays a critical role in hyperglycemia-induced myocardium dysfunction. Previous studies have demonstrated that Rosmarinic Acid (RA) treatment and activating Signal transducer and activator of transcription 3 (STAT3) signaling pathway have protective effects on mitochondrial dysfunction in cardiomyocyte, but there is little data regarding cardiomyocyte under condition of high-glucose. The present study was undertaken to determine the relationship between RA and STAT3 activation, as well as their effects on high glucose-induced mitochondrial injury and apoptosis in H9c2 cardiomyocyte. Our results revealed that RA pretreatment suppressed high glucose-induced apoptosis in H9c2 cells. Moreover, the effect of RA on apoptosis was related with improved mitochondrial function, which was demonstrated by that RA attenuated high glucose-induced ROS generation, inhibited mitochondrial permeability transition pore (MPTP) activation, suppressed cytochrome c release and caspase-3 activation. In addition, the phosphorylation of STAT3 in H9c2 cells was inhibited under condition of high-glucose, but RA improved STAT3 phosphorylation. Importantly, inhibition of STAT3 expression by using STAT3-siRNA partly suppressed the effect of RA on high glucose-induced apoptosis. Taken together, pretreatment with RA suppressed high glucose-induced apoptosis in cardiomyocyte by ameliorating mitochondrial function and activating STAT3. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Jujuboside A Protects H9C2 Cells from Isoproterenol-Induced Injury via Activating PI3K/Akt/mTOR Signaling Pathway

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    Dandan Han

    2016-01-01

    Full Text Available Jujuboside A is a kind of the saponins isolated from the seeds of Ziziphus jujuba, which possesses multiple biological effects, such as antianxiety, antioxidant, and anti-inflammatory effects; however, its mediatory effect on isoproterenol-stimulated cardiomyocytes has not been investigated yet. In this study, we tried to detect the protective effect and potential mechanism of JUA on ISO-induced cardiomyocytes injury. H9C2 cells were treated with ISO to induce cell damage. Cells were pretreated with JUA to investigate the effects on the cell viability, morphological changes, light chain 3 conversion, and the activation of PI3K/Akt/mTOR signaling pathway. Results showed that ISO significantly inhibited the cell viability in a time- and dose-dependent manner. JUA pretreatment could reverse the reduction of cell viability and better the injury of H9C2 cells induced by ISO. Western blot analysis showed that JUA could accelerate the phosphorylation of PI3K, Akt, and mTOR. Results also indicated that JUA could significantly decrease the ratio of microtubule-associated protein LC3-II/I in H9C2 cells. Taken together, our research showed that JUA could notably reduce the damage cause by ISO via promoting the phosphorylation of PI3K, Akt, and mTOR and inhibiting LC3 conversion, which may be a potential choice for the treatment of heart diseases.

  16. hHGF overexpression in myoblast sheets enhances their angiogenic potential in rat chronic heart failure.

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    Antti Siltanen

    Full Text Available After severe myocardial infarction (MI, heart failure results from ischemia, fibrosis, and remodeling. A promising therapy to enhance cardiac function and induce therapeutic angiogenesis via a paracrine mechanism in MI is myoblast sheet transplantation. We hypothesized that in a rat model of MI-induced chronic heart failure, this therapy could be further improved by overexpression of the antiapoptotic, antifibrotic, and proangiogenic hepatocyte growth factor (HGF in the myoblast sheets. We studied the ability of wild type (L6-WT and human HGF-expressing (L6-HGF L6 myoblast sheet-derived paracrine factors to stimulate cardiomyocyte, endothelial cell, or smooth muscle cell migration in culture. Further, we studied the autocrine effect of hHGF-expression on myoblast gene expression profiles by use of microarray analysis. We induced MI in Wistar rats by left anterior descending coronary artery (LAD ligation and allowed heart failure to develop for 4 weeks. Thereafter, we administered L6-WT (n = 15 or L6-HGF (n = 16 myoblast sheet therapy. Control rats (n = 13 underwent LAD ligation and rethoracotomy without therapy, and five rats underwent a sham operation in both surgeries. We evaluated cardiac function with echocardiography at 2 and 4 weeks after therapy, and analyzed cardiac angiogenesis and left ventricular architecture from histological sections at 4 weeks. Paracrine mediators from L6-HGF myoblast sheets effectively induced migration of cardiac endothelial and smooth muscle cells but not cardiomyocytes. Microarray data revealed that hHGF-expression modulated myoblast gene expression. In vivo, L6-HGF sheet therapy effectively stimulated angiogenesis in the infarcted and non-infarcted areas. Both L6-WT and L6-HGF therapies enhanced cardiac function and inhibited remodeling in a similar fashion. In conclusion, L6-HGF therapy effectively induced angiogenesis in the chronically failing heart. Cardiac function, however, was not further

  17. Ultrasound-targeted microbubble destruction (UTMD assisted delivery of shRNA against PHD2 into H9C2 cells.

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    Li Zhang

    Full Text Available Gene therapy has great potential for human diseases. Development of efficient delivery systems is critical to its clinical translation. Recent studies have shown that microbubbles in combination with ultrasound (US can be used to facilitate gene delivery. An aim of this study is to investigate whether the combination of US-targeted microbubble destruction (UTMD and polyethylenimine (PEI (UTMD/PEI can mediate even greater gene transfection efficiency than UTMD alone and to optimize ultrasonic irradiation parameters. Another aim of this study is to investigate the biological effects of PHD2-shRNA after its transfection into H9C2 cells. pEGFP-N1 or eukaryotic shPHD2-EGFP plasmid was mixed with albumin-coated microbubbles and PEI to form complexes for transfection. After these were added into H9C2 cells, the cells were exposed to US with various sets of parameters. The cells were then harvested and analyzed for gene expression. UTMD/PEI was shown to be highly efficient in gene transfection. An US intensity of 1.5 W/cm2, a microbubble concentration of 300μl/ml, an exposure time of 45s, and a plasmid concentration of 15μg/ml were found to be optimal for transfection. UTMD/PEI-mediated PHD2-shRNA transfection in H9C2 cells significantly down regulated the expression of PHD2 and increased expression of HIF-1α and downstream angiogenesis factors VEGF, TGF-β and bFGF. UTMD/PEI, combined with albumin-coated microbubbles, warrants further investigation for therapeutic gene delivery.

  18. Alcohol exposure increases the expression of cardiac transcription factors through ERK1/2-mediated histone3 hyperacetylation in H9c2 cells.

    Science.gov (United States)

    Gao, Wenqun; Pan, Bo; Liu, Lingjuan; Huang, Xupei; Liu, Zhenguo; Tian, Jie

    2015-10-30

    Alcohol abuse during pregnancy may cause fetal cardiac developmental abnormalities. Our previous studies showed that alcohol could induce histone hyperacetylation and over-expression of cardiac transcription factors both in vivo and in vitro. The objective of the present study was to investigate the role of ERK1/2 signaling pathway in alcohol-induced histone hyperacetylation and up-regulation of cardiac transcription factors in H9c2 cells. The Cardiac cell line H9c2 was cultured with alcohol. U0126, a specific inhibitor of ERK1/2 pathway was employed to block the ERK1/2 signaling pathway. Western blotting analysis showed that alcohol significantly enhanced the levels of phosphorylated ERK1/2 and induced hyperacetylation of histone3, which were both effectively prevented with U0126. Real-time PCR showed that U0126 treatment significantly decreased alcohol-induced over-expression of GATA4 and MEF2c, and the basal expression level of GATA4, but did not affect MEF2c. ChIP assay showed that U0126 treatment significantly decreased alcohol-induced hyperacetylation of histone3 near the promoter regions of GATA4 and MEF2c. The basal acetylation level of histone3 near the promoter region of GATA4 was affected by U0126 as well, but not that near the promoter region of MEF2c. These data indicated that ERK1/2 signaling played an important role in mediating alcohol induced over-expression of GATA4 and MEF2c, which is possibly through the up-regulation of acetylation of histone3 near the gene promoters that affects the expression of GATA4 and MEF2c in H9c2 cells. ERK1/2 pathway might be a potential target for the intervention of alcohol induced congenital heart diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Valporic acid enhances the Atrial Natriuretic Peptide (ANP) mediated anti-hypertrophic activity by modulating the Npr1 gene transcription in H9c2 cells in vitro.

    Science.gov (United States)

    Manivasagam, Senthamizharasi; Velusamy, Tamilselvi; Sowndharajan, Boopathi; Chandrasekar, Navvi; Dhanusu, Suresh; Vellaichamy, Elangovan

    2017-10-15

    The present study was aimed to determine whether stimulating Npr1 gene activity using Valporic acid (VA), a small short chain fatty acid molecule can enhance ANP mediated anti-hypertrophic activity in isoproterenol (ISO) - treated H9c2 cells in vitro. H9c2 cells were treated with ISO (10 -5 M) and co-treated with VA (10 -5 M) in the presence and absence of ANP (10 -8 M), for 48h. ATRA (10 -5 M) was used as a positive inducer of Npr1 gene transcription. The mRNA expression of Npr1 and PKG-I genes, proto-oncogenes (c-fos, c-jun and c-myc) and hypertrophic markers (ANP, BNP, α-sk and β-MyHC), genes were determined by quantitative PCR (qPCR). The protein profiling of NPR-A, PKG-I and cGMP were evaluated by Western blot, immunofluorescence and ELISA respectively. A marked reduction in the level of expression of Npr1 (3- fold) and PKG-I (2.5-fold) genes and increased expression of proto-oncogenes (pANP mediated anti-hypertrophic activity was enhanced with either VA (pANP can be a novel therapeutical approach for the treatment and management of left ventricular cardiac hypertrophy. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Protective role of Brassica olerecea and Eugenia jambolana extracts against H₂O₂ induced cytotoxicity in H9C2 cells.

    Science.gov (United States)

    Devkar, Ranjitsinh V; Pandya, Apurv V; Shah, Nancy H

    2012-08-01

    This study assesses the efficacy of anthocyanin rich Brassica olerecea leaves (ARCE) and flavonoid rich Eugenia jambolana seed (EJSE) extracts as possible cardioprotective agents against hydrogen peroxide (H(2)O(2)) induced cytotoxicity in H9C2 cells. Presence of ARCE or EJSE resulted in a superior cell viability and cell integrity as revealed by cell viability and lactate dehydrogenase release assays and acridine orange and ethidium bromide staining of control and H(2)O(2) treated H9C2 cells. These extracts were also able to reduce the impact of H(2)O(2) induced lipid peroxidation and depletion of intracellular glutathione. Also, there was an increase in mitochondrial membrane potential and reduced generation of intracellular reactive oxygen species following ARCE or EJSE treatments. These results suggest that ARCE and EJSE are capable of cardioprotective activity due to the high number of anthocyanins and flavonoids in them that are instrumental in lowering intracellular oxidative stress, preventing depletion of cellular antioxidants and improving cell viability.

  1. Remote loading of doxorubicin into liposomes by transmembrane pH gradient to reduce toxicity toward H9c2 cells

    Directory of Open Access Journals (Sweden)

    Mohamed Alyane

    2016-03-01

    Full Text Available The use of doxorubicin (DOX is limited by its dose-dependent cardiotoxicity. Entrapped DOX in liposome has been shown to reduce cardiotoxicity. Results showed that about 92% of the total drug was encapsulated in liposome. The release experiments showed a weak DOX leakage in both culture medium and in PBS, more than 98% and 90% of the encapsulated DOX respectively was still retained in liposomes after 24 h of incubation. When the release experiments were carried out in phosphate buffer pH5.3, the leakage of DOX from liposomes reached 37% after 24 h of incubation. Evaluation of cellular uptake of the liposomal DOX indicated the possible endocytosis of liposomes because the majority of visible fluorescence of DOX was mainly in the cytoplasm, whereas the nuclear compartment showed a weak intensity. When using unloaded fluorescent-liposomes, the fluorescence was absent in nuclei suggests that liposomes cannot cross the nuclear membrane. MTT assay and measurement of LDH release suggest that necrosis is the form of cellular death predominates in H9c2 cells exposed to high doses of DOX, while for weak doses apoptosis could be the predominate form. Entrapped DOX reduced significantly DOX toxicity after 3 and 6 h of incubation, but after 20 h entrapped DOX is more toxic than free one.

  2. S-propranolol protected H9C2 cells from ischemia/reperfusion-induced apoptosis via downregultion of RACK1 Gene.

    Science.gov (United States)

    Jia, Xiongfei; Zhang, Li; Mao, Xiaoqin

    2015-01-01

    Ischemia-reperfusion (I/R) injury can lead to apoptotic death of heart cells and subsequently heart failure. Propranolol is widely used in the management of cardiovascular disorders, but the mechanism is still unclear. Our previous studies showed that activated protein kinase C1 (RACK1) was significantly down-regulated in human umbilical vein endothelial cells by S-propranolol. RACK1 may be a target protein of S-propranolol during I/R. At present, we constructed a lentiviral expression vector for RNA interference (RNAi) of RACK1. The interference efficiency of the lentivirus was confirmed by RT-PCR and western blot. H9C2 cells infected with Lv-RACK1-shRNA or control were subjected to simulate I/R in the presence and absence of S-propranolol. The release of cytokines and chemokines was determined by ELISA assay. Flow cytometry was employed to determine mitochondrial membrane potential (MMP), Ca(2+) concentration, reactive oxygen species (ROS) production, and cell apoptosis. We found that RACK1 RNAi and S-propranolol treatment remarkably protected I/R injured cells from apoptosis via attenuating the release of cytokines and chemokines, Ca(2+) overload, ROS concentration, and MMP. Furthermore, RACK1 RNAi and S-propranolol, separately and in combination, significantly reduced caspase-3 activity, cytochrome c release and JNK activation. RACK 1 can be considered as a target for drug development.

  3. TSA protects H9c2 cells against thapsigargin-induced apoptosis related to endoplasmic reticulum stress-mediated mitochondrial injury.

    Science.gov (United States)

    Li, Zhiping; Liu, Yan; Dai, Xinlun; Zhou, Qiangqiang; Liu, Xueli; Li, Zeyu; Chen, Xia

    2017-05-01

    Endoplasmic reticulum stress (ERS) activates an adaptive unfolded protein response (UPR) that facilitates cellular repair, however, under prolonged ER stress, the UPR can ultimately trigger apoptosis thereby terminating damaged cells. Recently, TSA has shown protective effects on ERS and its mechanisms related to ER pathway has been previously characterized. However, whether TSA exerts its protective role via metabolic events remain largely undefined. Objectives: To explore the possible involvement of the metabolic changes during ERS and to better understand how TSA influence mitochondrial function to facilitate cellular adaptation. Results: TSA is an inhibitor of histone deacetylase which could significantly inhibit H9c2 cell apoptosis induced by Thapsigargin (TG). It also intervene the decrease of mitochondrial membrane potential. By immunofluorescence staining, we have shown that GRP78 was concentrated in the perinuclear region and co-localized with ER. However, treatments with TG and TSA could let it overlap with the mitochondrial marker MitoTracker. Cellular fractionation also confirmed the location of GRP78 in mitochondrion. TSA decreases ERS-induced cell apoptosis and mitochondrial injury may related to enhance the location of GRP78 in mitochondrion.

  4. Short-Term Hypoxia Reverses Ox-LDL-Induced CD36 and GLUT4 Switching Metabolic Pathways in H9c2 Cardiomyoblast Cells.

    Science.gov (United States)

    Chen, Yeh-Peng; Hsu, Hsi-Hsien; Baskaran, Rathinasamy; Wen, Su-Ying; Shen, Chia-Yao; Day, Cecilia-Hsuan; Ho, Tsung-Jung; Vijaya Padma, Viswanadha; Kuo, Wei-Wen; Huang, Chih-Yang

    2017-11-01

    High levels of circulating low-density lipoproteins (LDL, plasma proteins that carry cholesterol and triglycerides) are associated with type 2 diabetes, arteriosclerosis, obesity, and hyperlipidemia. In the heart, the accumulation of oxidized low-density lipoprotein (Ox-LDL) has been proposed to play a role in the development of cardiovascular disease. We obtain cholesterol from animals and animal-derived foods such as milk, eggs, and cheese. In previous studies, the ratio of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) was shown to be important for our health. High levels of LDL cholesterol lead to atherosclerosis, increasing the risk of heart attack and ischemic stroke. In this study, we utilized Ox-LDL-treated H9c2 cardiomyoblast cells as a simulated hyperlipidemia model. CD36 metabolism pathway proteins (phospho-Akt, SIRT1, PGC1α, PPARα, CPT1β, and CD36) increased at low doses of Ox-LDL. However, high doses (150 and 200 mg/dL) of Ox-LDL reduced the levels of these proteins. Interestingly, expression of GLUT4 metabolism pathway proteins (phospho-PKCζ) were reduced at low doses, while the expression of phospho-AMPK, phospho-PI3K, phospho-PKCζ, GLUT4, and PDH proteins increased at high doses. Ox-LDL acute treatment induces apoptosis in cardiomyocytes as evidenced by apoptotic nuclei apparition, caspase-3 activation, and cytochrome c release from mitochondria. In our results, Ox-LDL induced lipotoxicity in cardiomyocytes, and subsequent exposure to short-term hypoxia or reversed the Ox-LDL-induced metabolic imbalance. The same result was obtained with the pharmacological activation of SIRT1 by resveratrol and si-PKCζ. The mechanism of metabolic switching during Ox-LDL lipotoxicity seems to be mediated by SIRT1 and PKC ζ. J. Cell. Biochem. 118: 3785-3795, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. The Transcription Profile Unveils the Cardioprotective Effect of Aspalathin against Lipid Toxicity in an In Vitro H9c2 Model

    Directory of Open Access Journals (Sweden)

    Rabia Johnson

    2017-01-01

    Full Text Available Aspalathin, a C-glucosyl dihydrochalcone, has previously been shown to protect cardiomyocytes against hyperglycemia-induced shifts in substrate preference and subsequent apoptosis. However, the precise gene regulatory network remains to be elucidated. To unravel the mechanism and provide insight into this supposition, the direct effect of aspalathin in an isolated cell-based system, without the influence of any variables, was tested using an H9c2 cardiomyocyte model. Cardiomyocytes were exposed to high glucose (33 mM for 48 h before post-treatment with or without aspalathin. Thereafter, RNA was extracted and RT2 PCR Profiler Arrays were used to profile the expression of 336 genes. Results showed that, 57 genes were differentially regulated in the high glucose or high glucose and aspalathin treated groups. Search Tool for the Retrieval of Interacting Genes/Proteins (STRING analysis revealed lipid metabolism and molecular transport as the biological processes altered after high glucose treatment, followed by inflammation and apoptosis. Aspalathin was able to modulate key regulators associated with lipid metabolism (Adipoq, Apob, CD36, Cpt1, Pparγ, Srebf1/2, Scd1 and Vldlr, insulin resistance (Igf1, Akt1, Pde3 and Map2k1, inflammation (Il3, Il6, Jak2, Lepr, Socs3, and Tnf13 and apoptosis (Bcl2 and Chuk. Collectively, our results suggest that aspalathin could reverse metabolic abnormalities by activating Adipoq while modulating the expression of Pparγ and Srebf1/2, decreasing inflammation via Il6/Jak2 pathway, which together with an observed increased expression of Bcl2 prevents myocardium apoptosis.

  6. Eicosapentaenoic acid ameliorates palmitate-induced lipotoxicity via the AMP kinase/dynamin-related protein-1 signaling pathway in differentiated H9c2 myocytes.

    Science.gov (United States)

    Sakamoto, Atsushi; Saotome, Masao; Hasan, Prottoy; Satoh, Terumori; Ohtani, Hayato; Urushida, Tsuyoshi; Katoh, Hideki; Satoh, Hiroshi; Hayashi, Hideharu

    2017-02-01

    Emerging evidence suggested the preferable effects of eicosapentaenoic acid (EPA; n-3 polyunsaturated fatty acid) against cardiac lipotoxicity, which worsens cardiac function by means of excessive serum free fatty acids due to chronic adrenergic stimulation under heart failure. Nonetheless, the precise molecular mechanisms remain elusive. In this study, we focused on dynamin-related protein-1 (Drp1) as a possible modulator of the EPA-mediated cardiac protection against cardiac lipotoxicity, and investigated the causal relation between AMP-activated protein kinase (AMPK) and Drp1. When differentiated H9c2 myocytes were exposed to palmitate (PAL; saturated fatty acid, 400µM) for 24h, these myocytes showed activation of caspases 3 and 7, enhanced caspase 3 cleavage, depolarized mitochondrial membrane potential, depleted intracellular ATP, and enhanced production of intracellular reactive oxygen species. These changes suggested lipotoxicity due to excessive PAL. PAL enhanced mitochondrial fragmentation with increased Drp1 expression, as well. EPA (50µM) restored the PAL-induced apoptosis, mitochondrial dysfunction, and mitochondrial fragmentation with increased Drp1 expression by PAL. EPA activated phosphorylation of AMPK, and pharmacological activation of AMPK by 5-aminoimidazole-4-carboxamide ribonucleotide ameliorated the PAL-induced apoptosis, mitochondrial dysfunction, and downregulated Drp1. An AMPK knockdown via RNA interference enhanced Drp1 expression and attenuated the protective effects of EPA against the PAL-induced lipotoxicity. EPA ameliorates the PAL-induced lipotoxicity via AMPK activation, which subsequently suppresses mitochondrial fragmentation and Drp1 expression. Our findings may provide new insights into the molecular mechanisms of EPA-mediated myocardial protection in heart failure. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. T3 peptide, an active fragment of tumstatin, inhibits H2O2-induced apoptosis in H9c2 cardiomyoblasts.

    Science.gov (United States)

    Yasuda, Jumpei; Okada, Muneyoshi; Yamawaki, Hideyuki

    2017-07-15

    Tumstatin, a cleaved fragment of α3 chain of type IV collagen, is an endogenous anti-angiogenetic peptide. Although the expression level of tumstatin changes in the heart tissues of certain experimental cardiac disease models, its effect on cardiomyocytes has not been clarified. In this study, we examined the effects of T3 peptide, an active subfragment of tumstatin, on hydrogen peroxide (H 2 O 2 )-induced cell death in H9c2 cardiomyoblasts. Cell viability was examined by a cell counting assay. Staining using 4', 6-diamidino-2-phenylindole was performed to observe nuclear morphology. Western blotting was performed to examine cleaved caspase-3 expression. Mitochondrial membrane potential and morphology were detected by a Mito Tracker Red staining. Intracellular reactive oxygen species production was examined by 2', 7'-dichlorodihydrofluorescein diacetate staining. T3 peptide (300, 1000ng/ml) suppressed H 2 O 2 (1mM)-induced cell death, apoptotic changes of nuclei and cleaved caspas-3 expression in a concentration-dependent manner. T3 peptide also inhibited H 2 O 2 -induced loss of mitochondrial membrane potential, mitochondrial fission and reactive oxygen species production. Cilengitide, an integrin α v β 3 /α v β 5 inhibitor, prevents the inhibitory effect of T3 peptide on H 2 O 2 -induced reactive oxygen species production. In conclusion, T3 peptide inhibits H 2 O 2 -induced apoptosis at least partly via the inhibition of intracellular reactive oxygen species production through the action on integrin. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Combination of Nigella sativa with Glycyrrhiza glabra and Zingiber officinale augments their protective effects on doxorubicin-induced toxicity in h9c2 cells.

    Science.gov (United States)

    Hosseini, Azar; Shafiee-Nick, Reza; Mousavi, Seyed Hadi

    2014-12-01

    The use of doxorubicin (DOX) is limited by its dose-dependent cardio toxicity in which reactive Oxygen Species (ROS) play an important role in the pathological process. The aim of this study was to evaluate the protective effect of three medicinal plants, Nigella sativa (N), Glycyrrhiza glabra (G) and Zingiber officinale (Z), and their combination (NGZ), against DOX-induced apoptosis and death in H9c2 cells. The cells were incubated with different concentrations of each extract or NGZ for 4 hr which continued in the presence or absence of 5µM doxorubicin for 24 hr. Cell viability and the apoptotic rate were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) and propidium iodide (PI) staining assays, respectively. The level of ROS and lipid peroxidation were measured by fluorimetric methods. Treatment with doxorubicin increased ROS generation, enhanced malondialdehyde (MDA) formation, and induced apoptosis. Co-treatment of the cells with each herb extract increased viability of cells dose-dependently with a maximum protection effect of about 30%, and their potencies were N>G>Z. The combination of the threshold dose of each extract (NGZ) produced a similar effect, which was increased dose-dependently to a maximum protection of 70%. These effects were correlated with the effects of NGZ on ROS and MDA. All of the extracts have some protective effects against DOX-induced toxicity in cardiomyocytes with similar efficacies, but with different potencies. However, NGZ produced much higher protective effect via reducing oxidative stress and inhibiting of apoptotic induction processes. Further investigations are needed to determine the effects of NGZ on DOX chemotherapy.

  9. Selective inhibition of cathepsin B with cell-permeable CA074Me negatively affects L6 rat myoblast differentiation.

    Science.gov (United States)

    Jane, Derek T; Morvay, Leslie C; Allen, Francis; Sloane, Bonnie F; Dufresne, Michael J

    2002-01-01

    Active cathepsin B, in concert with other cellular proteases, has been implicated in the catabolic restructuring associated with myotube formation during skeletal myoblast cell differentiation (i.e., myogenesis). We have examined this role in differentiating myoblasts using the cell-permeable, cathepsin B selective inhibitor CA074Me. Cathepsin B activity levels in differentiating L6 rat myoblasts treated with CA074Me were significantly lower than levels in control myoblasts. Inhibition of cathepsin B activity by CA074Me occurred at each stage of differentiation and was dose related. Myotube size and number and induced levels of fusion-related creatine phosphokinase activity and myosin heavy-chain protein were reduced from 30 to 50% in CA074Me-treated myoblasts. These reductions were also dose related. In contrast, CA074Me did not affect levels of myogenin, an early marker of myogenesis, or levels of cathepsin L type and myokinase activities, two nonspecific enzymes. The negative effects associated with CA074Me were reversed when the drug was removed. Collectively, these data suggest that active cathepsin B plays a role in myoblast-myoblast fusion and consequently may be necessary for the complete expression of those genes associated with the fusion process.

  10. The volatile oil of Nardostachyos Radix et Rhizoma inhibits the oxidative stress-induced cell injury via reactive oxygen species scavenging and Akt activation in H9c2 cardiomyocyte.

    Science.gov (United States)

    Maiwulanjiang, Maitinuer; Chen, Jianping; Xin, Guizhong; Gong, Amy G W; Miernisha, Abudureyimu; Du, Crystal Y Q; Lau, Kei M; Lee, Pinky S C; Chen, Jihang; Dong, Tina T X; Aisa, Haji A; Tsim, Karl W K

    2014-04-28

    Nardostachyos Radix et Rhizoma (NRR; the root and rhizome of Nardostachys jatamansi DC.) is a well-known medicinal herb widely used in Chinese, Uyghur and Ayurvedic medicines for the treatment of cardiovascular disorders. The oxidative stress-induced cardiomyocyte loss is the major pathogenesis of heart disorders. Here, the total volatile oil of NRR was isolated, and its function in preventing the cell death of cardiomyocyte was demonstrated. The cyto-protective effect of volatile oil of NRR against tBHP-induced H9c2 cardiomyocyte injury was measured by MTT assay. A promoter-report construct (pARE-Luc) containing four repeats of antioxidant response element (ARE) was applied to study the transcriptional activation of ARE. The amounts of phase ΙΙ antioxidant enzymes were analyzed by quantitative real-time polymer chain reaction (qPCR) upon the volatile oil treatment at 30 μg/mL for 24 h. The activation of Akt pathway was analyzed by western blot. In cultured H9c2 cardiomyocytes, application of NRR volatile oil exhibited strong potency in preventing tBHP-induced cell death and accumulation of intracellular reactive oxygen species (ROS) in a concentration-dependent manner. In addition, the application of NRR volatile oil in cultures stimulated the gene expressions of self-defense antioxidant enzymes, which was mediated by the transcriptional activation of antioxidant response element (ARE). The induced genes were glutathione S-transferase, NAD(P)H quinone oxidoreductase, glutamate-cysteine ligase catalytic and modulatory subunits. In addition, the volatile oil of NRR activated the phosphorylation of Akt in cultured H9c2 cells. The treatment of LY294002, an Akt inhibitor, significantly inhibited the volatile oil-mediated ARE transcriptional activity, as well as the cell protective effect of NRR oil. These results demonstrated that NRR volatile oil prevented the oxidative stress-induced cell death in H9c2 cells by (i) reducing intracellular ROS production, (ii

  11. Effects of bpV(pic) and bpV(phen) on H9c2 cardiomyoblasts during both hypoxia/reoxygenation and H2O2-induced injuries.

    Science.gov (United States)

    Tian, Youqing; Daoud, Abdelkader; Shang, Jing

    2012-03-01

    Reactive oxygen species (ROS) are involved in myocardial injury. ROS are known to inactivate lipid phosphatase and tension homolog on chromosome 10 (PTEN), an enzyme that increases apoptosis in neonatal cardiomyocytes. BpV(pic) and bpV(phen), two bisperoxovanadium molecules and PTEN inhibitors, may be involved in limiting myocardial infarction. To compare the protective effects of bpV(pic) and bpV(phen) on ROS-induced cardiomyocyte injury and their possible mechanisms, we selected two popular models of hypoxia/reoxygenation (H/R) and H2O2-induced injury in H9c2 cardiomyoblasts to investigate their effects against injury. We found that pre-treatment with bpV(pic) and bpV(phen) increased the viability and protected the morphology of H9c2 cells under the conditions of H/R and H2O2 by inhibiting LDH release, apoptosis and caspases 3/8/9 activities. However, their respective inhibitory abilities in the two models were different, suggesting that the quantity of ROS from the two models might be different. However, the conflict between ROS and PTEN may affect the action of bpV(pic) and bpV(phen). Taken together, the results demonstrate that bpV(pic) and bpV(phen) have inhibitory effects on oxidative stress-induced cardiomyocyte injury that may be partially modulated by the action of ROS on PTEN.

  12. Effect of atrophy and contractions on myogenin mRNA concentration in chick and rat myoblast omega muscle cells

    Science.gov (United States)

    Krebs, J. M.; Denney, R. M.

    1997-01-01

    The skeletal rat myoblast omega (RMo) cell line forms myotubes that exhibit spontaneous contractions under appropriate conditions in culture. We examined if the RMo cells would provide a model for studying atrophy and muscle contraction. To better understand how to obtain contractile cultures, we examined levels of contraction under different growing conditions. The proliferation medium and density of plating affected the subsequent proportion of spontaneously contracting myotubes. Using a ribonuclease protection assay, we found that exponentially growing RMo myoblasts contained no detectable myogenin or herculin mRNA, while differentiating myoblasts contained high levels of myogenin mRNA but no herculin mRNA. There was no increase in myogenin mRNA concentration in either primary chick or RMo myotubes whose contractions were inhibited by depolarizing concentrations of potassium (K+). Thus, altered myogenin mRNA concentrations are not involved in atrophy of chick myotubes. Depolarizing concentrations of potassium inhibited spontaneous contractions in both RMo cultures and primary chick myotube cultures. However, we found that the myosin concentration of 6-d-old contracting RMo cells fed medium plus AraC was 11 +/- 3 micrograms myosin/microgram DNA, not significantly different from 12 +/- 4 micrograms myosin/microgram DNA (n = 3), the myosin concentration of noncontracting RMo cells (treated with 12 mM K+ for 6 d). Resolving how RMo cells maintained their myosin content when contraction is inhibited may be important for understanding atrophy.

  13. Quantitative profiling of the rat heart myoblast secretome reveals differential responses to hypoxia and re-oxygenation stress.

    Science.gov (United States)

    Li, Xin; Ren, Yan; Sorokin, Vitaly; Poh, Kian Keong; Ho, Hee Hwa; Lee, Chuen Neng; de Kleijn, Dominique; Lim, Sai Kiang; Tam, James P; Sze, Siu Kwan

    2014-02-26

    Secretion of bioactive mediators regulates cell interactions with the microenvironment in tissue homeostasis and wound healing processes. We assessed the cardiomyocyte secretory response to hypoxia with the aim of identifying key mediators of tissue pathology and repair after ischemic heart attack. We profiled the secretome of rat H9C2 cardiomyoblast cells subjected to 16h hypoxia followed by 24h re-oxygenation using iTRAQ and label-free quantitative proteomics. A total of 860 and 2007 proteins were identified in the iTRAQ and label-free experiments respectively. Among these proteins, 1363 were identified as being secreted proteins, including mediators of critical cellular functions that were modulated by hypoxia/re-oxygenation stress (SerpinH1, Ppia, Attractin, EMC1, Postn, Thbs1, Timp1, Stip1, Robo2, Fat1). Further analysis indicated that hypoxia is associated with angiogenesis, inflammation, and remodeling of the extracellular matrix (ECM), whereas subsequent re-oxygenation was instead associated with modified secretion of proteins involved in suppression of inflammation, ECM modification, and decreased output of anti-apoptosis proteins. These data indicate that hypoxia and subsequent re-oxygenation modify the cardiomyocyte secretome in order to mitigate cellular injury and promote healing. The identified changes in cardiomyocyte secretome advance our current understanding of cardiac biology in ischemia/reperfusion injury and may lead to the identification of novel prognostic biomarker. Cardiovascular diseases (CVDs) are the leading cause of death globally. Myocardial infarction (MI) resulting from ischemic heart disease represents a substantial component of CVD-associated mortality, and is associated with obstruction of blood flow to the myocardium. Restoration of blood flow through the occluded coronary artery is the current most effective therapy to limit infarct size and preserve cardiac function after acute myocardial infarction. However, this treatment

  14. Biological Effect of Licochalcone C on the Regulation of PI3K/Akt/eNOS and NF-κB/iNOS/NO Signaling Pathways in H9c2 Cells in Response to LPS Stimulation.

    Science.gov (United States)

    Franceschelli, Sara; Pesce, Mirko; Ferrone, Alessio; Gatta, Daniela Maria Pia; Patruno, Antonia; Lutiis, Maria Anna De; Quiles, José Luis; Grilli, Alfredo; Felaco, Mario; Speranza, Lorenza

    2017-03-23

    Polyphenols compounds are a group molecules present in many plants. They have antioxidant properties and can also be helpful in the management of sepsis. Licochalcone C (LicoC), a constituent of Glycyrrhiza glabra, has various biological and pharmacological properties. In saying this, the effect of LicoC on the inflammatory response that characterizes septic myocardial dysfunction is poorly understood. The aim of this study was to determine whether LicoC exhibits anti-inflammatory properties on H9c2 cells that are stimulated with lipopolysaccharide. Our results have shown that LicoC treatment represses nuclear factor-κB (NF-κB) translocation and several downstream molecules, such as inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Moreover, LicoC has upregulated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/endothelial nitric oxide synthase (eNOS) signaling pathway. Finally, 2-(4-Morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002), a specific PI3K inhibitor, blocked the protective effects of LicoC. These findings indicate that LicoC plays a pivotal role in cardiac dysfunction in sepsis-induced inflammation.

  15. FIP2 and Rip11 specify Rab11a-mediated cellular distribution of GLUT4 and FAT/CD36 in H9c2-hIR cells.

    Science.gov (United States)

    Schwenk, Robert W; Luiken, Joost J F P; Eckel, Jürgen

    2007-11-09

    Rab11a has been shown to be involved in different vesicle trafficking processes. To further define the functional role of Rab11a in vesicle movement we knocked down gene expression of Rab11a and two of its effectors, Rip11 and FIP2, in H9c2-hIR cells and measured the cell surface abundance of GLUT4myc and FAT/CD36. We observed that by knocking down Rab11a, both GLUT4myc and FAT/CD36 abundance at the plasma membrane were substantially increased. In the case of GLUT4myc, the in vitro knockdown of FIP2 also increased the cell surface abundance of GLUT4myc. Knockdown of both FIP2 and Rip11 increase the abundance of FAT/CD36 at the plasma membrane. Stimulated translocation of GLUT4myc and FAT/CD36 is not altered after gene knockdown of Rab11a. These data therefore show that (i) Rab11a regulates cell surface abundance of both GLUT4 and FAT/CD36 and that (ii) both Rab11a-dependent processes are differently regulated by Rab11a effector proteins.

  16. Malonyl-CoA decarboxylase (MCD) is differentially regulated in subcellular compartments by 5'AMP-activated protein kinase (AMPK). Studies using H9c2 cells overexpressing MCD and AMPK by adenoviral gene transfer technique.

    Science.gov (United States)

    Sambandam, Nandakumar; Steinmetz, Michael; Chu, Angel; Altarejos, Judith Y; Dyck, Jason R B; Lopaschuk, Gary D

    2004-07-01

    Malonyl-CoA, a potent inhibitor of carnitine pamitoyl transferase-I (CPT-I), plays a pivotal role in fuel selection in cardiac muscle. Malonyl-CoA decarboxylase (MCD) catalyzes the degradation of malonyl-CoA, removes a potent allosteric inhibition on CPT-I and thereby increases fatty acid oxidation in the heart. Although MCD has several Ser/Thr phosphorylation sites, whether it is regulated by AMP-activated protein kinase (AMPK) has been controversial. We therefore overexpressed MCD (Ad.MCD) and constitutively active AMPK (Ad.CA-AMPK) in H9c2 cells, using an adenoviral gene delivery approach in order to examine if MCD is regulated by AMPK. Cells infected with Ad.CA-AMPK demonstrated a fourfold increase in AMPK activity as compared with control cells expressing green fluorescent protein (Ad.GFP). MCD activity increased 40- to 50-fold in Ad.MCD + Ad.GFP cells when compared with Ad.GFP control. Co-expressing AMPK with MCD further augmented MCD expression and activity in Ad.MCD + Ad.CA-AMPK cells compared with the Ad.MCD + Ad.GFP control. Subcellular fractionation further revealed that 54.7 kDa isoform of MCD expression was significantly higher in cytosolic fractions of Ad.MCD + Ad.CA-AMPK cells than of the Ad.MCD +Ad.GFP control. However, the MCD activities in cytosolic fractions were not different between the two groups. Interestingly, in the mitochondrial fractions, MCD activity significantly increased in Ad.MCD + Ad.CA-AMPK cells when compared with Ad.MCD + Ad.GFP cells. Using phosphoserine and phosphothreonine antibodies, no phosphorylation of MCD by AMPK was observed. The increase in MCD activity in mitochondria-rich fractions of Ad.MCD + Ad.CA-AMPK cells was accompanied by an increase in the level of the 50.7 kDa isoform of MCD protein in the mitochondria. This differential regulation of MCD expression and activity in the mitochondria by AMPK may potentially regulate malonyl-CoA levels at sites nearby CPT-I on the mitochondria.

  17. Myoblast-based cardiac repair: xenomyoblast versus allomyoblast transplantation.

    Science.gov (United States)

    Guo, Changfa; Haider, Husnain Kh; Shim, Winston S N; Tan, Ru-San; Ye, Lei; Jiang, Shujia; Law, Peter K; Wong, Philip; Sim, Eugene K W

    2007-11-01

    We sought to investigate immune cell kinetics in relation to skeletal myoblast survival and heart function improvement after nonautologous skeletal myoblast transplantation in a rat model of myocardial infarction. One week after myocardial infarction, 208 Wistar rats were grouped into group 1 (n = 24, receiving 150 muL of medium only), group 2 (n = 24, receiving 150 muL of medium and cyclosporine [INN: ciclosporin]), group 3 (n = 40, human skeletal myoblast transplantation), group 4 (n = 40, human skeletal myoblast transplantation with cyclosporine treatment), group 5 (n = 40, rat skeletal myoblast transplantation), and group 6 (n = 40, rat skeletal myoblast transplantation with cyclosporine treatment). The hearts were harvested at 10 minutes and 1, 4, 7, and 28 days after cell transplantation. Skeletal myoblast survival was confirmed by means of immunohistochemical studies and quantified by using real-time polymerase chain reaction. Host immune responses were assessed by immunostaining for macrophages and CD4+ and CD8+ lymphocytes. Heart function was evaluated by means of echocardiographic analysis. The majority of macrophages and lymphocytes infiltrated in the acute phase (from day 1 to day 7) and then subsided by day 28. The donor skeletal myoblasts survived and differentiated well in all skeletal myoblast transplantation groups. Allogeneic skeletal myoblasts showed a superior survival rate than xenogeneic skeletal myoblasts (P Cyclosporine inhibited the infiltration of the immunocytes, enhanced skeletal myoblast survival, and improved heart performance compared with that seen in the groups not receiving cyclosporine treatment (P transplantation into infarcted myocardium. After inhibition of immunocyte infiltration by means of immunosuppressive treatment, skeletal myoblast survival is enhanced, with improved heart performance. These findings suggest the feasibility of nonautologous myoblast transplantation with immunosuppressive treatment.

  18. Choice of cell-delivery route for skeletal myoblast transplantation for treating post-infarction chronic heart failure in rat.

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    Satsuki Fukushima

    2008-08-01

    Full Text Available Intramyocardial injection of skeletal myoblasts (SMB has been shown to be a promising strategy for treating post-infarction chronic heart failure. However, insufficient therapeutic benefit and occurrence of ventricular arrhythmias are concerns. We hypothesised that the use of a retrograde intracoronary route for SMB-delivery might favourably alter the behaviour of the grafted SMB, consequently modulating the therapeutic effects and arrhythmogenicity.Three weeks after coronary artery ligation in female wild-type rats, 5x10(6 GFP-expressing SMB or PBS only (control were injected via either the intramyocardial or retrograde intracoronary routes. Injection of SMB via either route similarly improved cardiac performance and physical activity, associated with reduced cardiomyocyte-hypertrophy and fibrosis. Grafted SMB via either route were only present in low numbers in the myocardium, analysed by real-time PCR for the Y-chromosome specific gene, Sry. Cardiomyogenic differentiation of grafted SMB was extremely rare. Continuous ECG monitoring by telemetry revealed that only intramyocardial injection of SMB produced spontaneous ventricular tachycardia up to 14 days, associated with local myocardial heterogeneity generated by clusters of injected SMB and accumulated inflammatory cells. A small number of ventricular premature contractions with latent ventricular tachycardia were detected in the late-phase of SMB injection regardless of the injection-route.Retrograde intracoronary injection of SMB provided significant therapeutic benefits with attenuated early-phase arrhythmogenicity in treating ischaemic cardiomyopathy, indicating the promising utility of this route for SMB-delivery. Late-phase arrhythmogenicity remains a concern, regardless of the delivery route.

  19. Effects of Ghrelin on Triglyceride Accumulation and Glucose Uptake in Primary Cultured Rat Myoblasts under Palmitic Acid-Induced High Fat Conditions

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    Lingling Han

    2015-01-01

    Full Text Available This study aimed to study the effects of acylated ghrelin on glucose and triglyceride metabolism in rat myoblasts under palmitic acid- (PA- induced high fat conditions. Rat myoblasts were treated with 0, 10−11, 10−9, or 10−7 M acylated ghrelin and 0.3 mM PA for 12 h. Triglyceride accumulation was determined by Oil-Red-O staining and the glycerol phosphate dehydrogenase-peroxidase enzymatic method, and glucose uptake was determined by isotope tracer. The glucose transporter 4 (GLUT4, AMP-activated protein kinase (AMPK, acetyl-CoA carboxylase (ACC, and uncoupling protein 3 (UCP3 were assessed by RT-PCR and western blot. Compared to 0.3 mM PA, ghrelin at 10−9 and 10−7 M reduced triglyceride content (5.855 ± 0.352 versus 5.030 ± 0.129 and 4.158 ± 0.254 mM, P<0.05 and prevented PA-induced reduction of glucose uptake (1.717 ± 0.264 versus 2.233 ± 0.333 and 2.333 ± 0.273 10−2 pmol/g/min, P<0.05. The relative protein expression of p-AMPKα/AMPKα, UCP3, and p-ACC under 0.3 mM PA was significantly reduced compared to controls (all P<0.05, but those in the 10−9 and 10−7 M ghrelin groups were significantly protected from 0.3 mM PA (all P<0.05. In conclusion, acylated ghrelin reduced PA-induced triglyceride accumulation and prevented the PA-induced decrease in glucose uptake in rat myoblasts. These effects may involve fatty acid oxidation.

  20. FGF-2 Transcriptionally Down-Regulates the Expression of BNIP3L via PI3K/Akt/FoxO3a Signaling and Inhibits Necrosis and Mitochondrial Dysfunction Induced by High Concentrations of Hydrogen Peroxide in H9c2 Cells

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    Qian Chen

    2016-12-01

    Full Text Available Background/Aims: Cardiovascular disease is a growing major global public health problem. Necrosis is one of the main forms of cardiomyocyte death in heart disease. Oxidative stress is regarded as one of the key regulators of cardiac necrosis, which eventually leads to cardiovascular disease. Many pharmacological and in vitro studies have suggested that FGF-2 can act directly on cardiomyocytes to maintain the integrity and function of the myocardium and prevent damage during oxidative stress. However, the mechanisms by which FGF-2 rescues the myocardium from oxidative stress damage in cardiovascular disease remain unclear. The present study explored the protective effects of FGF-2 in the H2O2-induced necrosis of H9C2 cardiomyocytes as well as the possible signaling pathways involved. Methods: Necrosis of H9c2 cardiomyocytes was induced by H2O2 and assessed using a Cell Counting Kit-8 (CCK8 assay and flow cytometry analysis. The cells were pretreated with the PI3K/Akt inhibitor Wortmannin to investigate the possible involvement of the PI3K/Akt pathway in the protection by FGF-2. The levels of Akt, p-Akt, FoxO3a, p-FoxO3a, and BNIP3L were detected by Western blot. Chromatin immuno-precipitation (ChIP analysis was used to test whether FoxO3a binds directly to the BNIP3L promoter region. A luciferase assay was used to study the effects of FoxO3a on BNIP3L gene promoter activity. Mitochondrial ΔΨM was quantified using tetramethylrhodamine methyl ester perchlorate (TMRM. The mitochondrial oxygen consumption rate (OCR was assessed with a Seahorse XF24 Analyzer. Results: Treatment with H2O2 decreased the phosphorylation of Akt and FoxO3a, and it induced the nuclear localization of FoxO3a and the necrosis of H9c2 cells. These effects of H2O2 were abrogated by pretreatment with FGF-2. Furthermore, the protective effects of FGF-2 were abolished by the PI3K/Akt inhibitor Wortmannin. ChIP analyses indicated that FoxO3a binds directly to the BNIP3L promoter

  1. Low-after-high glucose down-regulated Cx43 in H9c2 cells by autophagy activation via cross-regulation by the PI3K/Akt/mTOR and MEK/ERK1/2 signal pathways.

    Science.gov (United States)

    Bi, Yaguang; Wang, Guangyu; Liu, Xiangdong; Wei, Meng; Zhang, Qingyong

    2017-05-01

    Hypoglycemia in diabetes is a strong predictor of cardiovascular events. High-glucose have been reported to alter connexin43 expression and to promote autophagy in cardiomyocytes. We investigated whether low-after-high glucose would influence connexin43 expression and autophagy in H9c2 cells. H9c2 cells were incubated in 33.3 mM glucose for 24 h followed by 2.5 mM glucose for 2, 4, 6, or 12 h with or without chloroquine (autophagy inhibitor), U0126 (MEK1/2 inhibitor) or LY294002 (PI3K inhibitor). Cells incubated in 5.5, 33.3, or 2.5 mM glucose with or without inhibitors and in the presence of mannitol were used as controls. Protein expression was assayed by western blot, apoptosis was assayed by flow cytometry, cell proliferation was determined by MTT assays, and cytotoxicity was assayed by lactate dehydrogenase measurement. Cytotoxicity and early apoptosis were increased and cell proliferation was decreased after exposure to low-after-high glucose, and these results were reversed by chloroquine and U0126 but were aggravated by LY294002. Connexin43 expression was downregulated in a time-dependent manner and was accompanied by upregulated expression of LC3-II, Beclin-1, p62, p-Akt, p-mTOR, and p-ERK1/2. Chloroquine suppressed autophagy and reversed the downregulation of connexin43. U0126 inhibited ERK activation and decreased autophagy proteins expression but increased connexin43 expression. LY294002 suppressed p-Akt, activated autophagy, and decreased connexin43 expression. Interestingly, MEK1/2 inhibition also increased p-Akt expression, but inhibition of PI3K led to p-ERK downregulation. Culturing H9c2 cells under low-after-high glucose downregulated connexin43 by promoting autophagy through a mechanism involving the PI3K/Akt/mTOR and MEK/ERK1/2 signaling pathways.

  2. Keap1 redox-dependent regulation of doxorubicin-induced oxidative stress response in cardiac myoblasts

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    Nordgren, Kendra K.S., E-mail: knordgre@d.umn.edu; Wallace, Kendall B., E-mail: kwallace@d.umn.edu

    2014-01-01

    Doxorubicin (DOX) is a widely prescribed treatment for a broad scope of cancers, but clinical utility is limited by the cumulative, dose-dependent cardiomyopathy that occurs with repeated administration. DOX-induced cardiotoxicity is associated with the production of reactive oxygen species (ROS) and oxidation of lipids, DNA and proteins. A major cellular defense mechanism against such oxidative stress is activation of the Keap1/Nrf2-antioxidant response element (ARE) signaling pathway, which transcriptionally regulates expression of antioxidant genes such as Nqo1 and Gstp1. In the present study, we address the hypothesis that an initial event associated with DOX-induced oxidative stress is activation of the Keap1/Nrf2-dependent expression of antioxidant genes and that this is regulated through drug-induced changes in redox status of the Keap1 protein. Incubation of H9c2 rat cardiac myoblasts with DOX resulted in a time- and dose-dependent decrease in non-protein sulfhydryl groups. Associated with this was a near 2-fold increase in Nrf2 protein content and enhanced transcription of several of the Nrf2-regulated down-stream genes, including Gstp1, Ugt1a1, and Nqo1; the expression of Nfe2l2 (Nrf2) itself was unaltered. Furthermore, both the redox status and the total amount of Keap1 protein were significantly decreased by DOX, with the loss of Keap1 being due to both inhibited gene expression and increased autophagic, but not proteasomal, degradation. These findings identify the Keap1/Nrf2 pathway as a potentially important initial response to acute DOX-induced oxidative injury, with the primary regulatory events being the oxidation and autophagic degradation of the redox sensor Keap1 protein. - Highlights: • DOX caused a ∼2-fold increase in Nrf2 protein content. • DOX enhanced transcription of several Nrf2-regulated down-stream genes. • Redox status and total amount of Keap1 protein were significantly decreased by DOX. • Loss of Keap1 protein was due to

  3. Compatibility of hyaluronic acid hydrogel and skeletal muscle myoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wei; Zhang Li; Sun Liang; Wang Chengyue [Jinzhou Central Hospital, Jinzhou 121000 (China); Fan Ming; Liu Shuhong, E-mail: Weiwang_Ly@yahoo.com.c [Institute of Basic Medical Sciences, Academy of Military Medical Science, Beijing 100850 (China)

    2009-04-15

    Compatibility of hyaluronic acid hydrogel (HAH) and skeletal muscle myoblasts has been investigated for the first time in the present paper. Skeletal muscle myoblasts were separated from skeletons of rats and incubated with a HAH-containing culture medium. Cell morphology, hydrophilicity and cell adhesion of the HAH scaffold were investigated using optical microscopy, scanning electron microscopy, Hoechest33258 fluorescent staining, the immunocytochemistry method and water adsorption rate measurement. It was found that at a proper concentration (around 0.5%) of hyaluronic acid, the hydrogel possessed good compatibility with skeletal muscle myoblasts. The hydrogel can create a three-dimensional structure for the growth of skeletal muscle myoblasts and benefit cell attachment to provide a novel scaffold material for the tissue engineering of skeletal muscle.

  4. Myoblast transplantation for cardiac repair: from automyoblast to allomyoblast transplantation.

    Science.gov (United States)

    Guo, Changfa; Haider, Husnain Kh; Wang, Chunsheng; Tan, Ru-San; Shim, Winston S N; Wong, Philip; Sim, Eugene K W

    2008-12-01

    We sought to compare host immune cell kinetics, survival profile of donor skeletal myoblasts, and skeletal myoblast graft efficacy after autologous and allogeneic skeletal myoblast transplantation into a rat model of myocardial infarction. One week after myocardial infarction, 128 animals were divided into four groups: group 1 (n = 24, receiving medium only), group 2 (n = 24, receiving medium and cyclosporine), group 3 (n = 40, autologous skeletal myoblast transplantation), and group 4 (n = 40, allogeneic skeletal myoblast transplantation with cyclosporine treatment). Rats were euthanized 10 minutes, 1 day, and 4, 7, and 28 days later. Host immune cell kinetics were assessed by immunohistochemical studies for macrophages, and CD4+ and CD8+ lymphocytes. Donor skeletal myoblast survival was confirmed by tracking prelabeled signals, and quantified by beta-gal assay. Heart function was evaluated by echocardiography. A transient immune cell infiltration was demonstrated in group 3, with macrophage infiltration on day 1 and day 4, CD8+ cell infiltration on day 4 and day 7, and CD4+ cell infiltration on day 4. In group 4, immunocyte infiltration was slightly more severe than that in group 3. Automyoblasts and allomyoblasts showed no significant difference of survival from day 1 to day 7 (p > 0.10); however, on day 28, automyoblasts showed better survival than allomyoblasts (p Transplantation of allomyoblasts increased systolic heart function and limited heart dilation after myocardial injury to a similar degree as automyoblasts (p > 0.10). The use of allomyoblasts is feasible and effective for cardiac repair with immunosuppressive treatment as compared with automyoblasts.

  5. Syncytin-1 in differentiating human myoblasts

    DEFF Research Database (Denmark)

    Bjerregard, Bolette; Ziomkiewicz, Iwona; Schulz, Alexander

    2014-01-01

    Myoblasts fuse to form myotubes, which mature into skeletal muscle fibres. Recent studies indicate that an endogenous retroviral fusion gene, syncytin-1, is important for myoblast fusions in man. We have now expanded these data by examining the immunolocalization of syncytin in human myoblasts...... fusions. Thus, syncytin is involved in human myoblast fusions and is localized in areas of contact between fusing cells. Moreover, syncytin and caveolin-3 might interact at the level of the sarcolemma....

  6. Induction of c-myc and c-jun proto-oncogene expression in rat L6 myoblasts by cadmium is inhibited by zinc preinduction of the metallothionein gene

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    Abshire, M.K.; Buzard, G.S.; Shiraishi, Noriyuki; Waalkers, M.P. [National Cancer Institute, Fredrick, MD (United States)

    1996-07-01

    Certain proto-oncogenes transfer growth regulatory signals from the cell surface to the nucleus. These genes often show activation soon after cells are exposed to mitogenic stimulation but can also be activated as a nonmitogenic stress response. Cadmium (Cd) is a carcinogenic metal in humans and rodents and, though its mechanism of action is unknown, it could involve activation of such proto-oncogenes. Metallothionein (MT), a metal-inducible protein that binds Cd, can protect against many aspects of Cd toxicity, including genotoxicity and possibly carcinogenesis. Thus, the effects of Cd on expression of c-myc and c-jun in rat L6 myoblasts, and the effect of preactivation of the MT gene by Zn treatment on such oncogene expression, were studied. MT protein levels were measured using oligonucleotide hybridization and standardized to {beta}-actin levels. Cd (5 {mu}M CdCl{sub 2}, 0-30 h) stimulated both c-myc and c-jun mRNA expression. An initial peak of activation of c-myc expression occurred 2 h after initiation of Cd exposure, and levels remained elevated throughout the assessment period. Zn pretreatment markedly reduced the activation of c-myc expression by Cd compared to cells not receiving Zn pretreatment. Cd treatment increased c-jun mRNA levels by up to 3.5-fold. Again, Zn pretreatment markedly reduced. 10 refs., 8 figs.

  7. Polyurethane scaffolds seeded with genetically engineered skeletal myoblasts: a promising tool to regenerate myocardial function.

    Science.gov (United States)

    Blumenthal, Britta; Golsong, Peter; Poppe, Annika; Heilmann, Claudia; Schlensak, Christian; Beyersdorf, Friedhelm; Siepe, Matthias

    2010-02-01

    In animal models, intramyocardial injection of primary skeletal myoblasts is supposed to promote tissue regeneration and to improve cardiac function after myocardial infarction. The usage of genetically engineered myoblasts overexpressing the paracrine factors involved in tissue repair is believed to enhance these effects. However, cell therapy via injection is always accompanied by a high death rate of the injected cells. Here, we describe the construction of a growth factor-producing myoblast-seeded scaffold to overcome this limitation. Skeletal myoblasts were isolated and expanded from newborn Lewis rats. Cells were seeded on polyurethane (PU) scaffolds (Artelon) and transfected with DNA of VEGF-A, HGF, SDF-1, or Akt1 using the lipid-based Metafectene Pro method. Overexpression was verified by ELISA, RT-PCR (VEGF-A, HGF, and SDF-1) and Western blot analysis (Akt1). The seeded scaffolds were transplanted onto damaged myocardium of Lewis rats 2 weeks after myocardial infarction. Six weeks later, their therapeutic potential in vivo was analyzed by measurement of infarction size and capillary density. Primary rat skeletal myoblasts seeded on PU scaffolds were efficiently transfected, achieving transfection rates of 20%. In vitro, we noted a significant increase in expression of VEGF-A, HGF, SDF-1, and Akt1 after transfection. In vivo, transplantation of growth factor-producing myoblast-seeded scaffolds resulted in enhanced angiogenesis (VEGF-A, HGF, and Akt1) or a reduced infarction zone (SDF-1 and Akt1) in the ischemically damaged myocardium. In summary, we constructed a growth factor-producing myoblast-seeded scaffold which combines the beneficial potential of stem cell transplantation with the promising effects of gene-therapeutic approaches. Because this matrix also allows us to circumvent previous cell application drawbacks, it may represent a promising tool for tissue regeneration and the re-establishment of cardiac function after myocardial infarction.

  8. Cardioprotective effects of PKG activation by soluble GC activator, BAY 60-2770, in ischemia-reperfusion-injured rat hearts.

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    Kyung Hye Lee

    Full Text Available Soluble guanylate cyclase (sGC has been suggested as a therapeutic target for cardiac ischemia-reperfusion (IR injury. Until now, the molecular mechanism of BAY 60-2770, a sGC activator, in cardiac IR injury has not been assessed. To identify the cardioprotective effects of BAY 60-2770 in IR-injured rat hearts, IR injury was established by occlusion of LAD for 40 min and reperfusion for 7 days, and the effects of BAY 60-2770 on myocardial protection were assessed by echocardiography and TTC staining. 5 nM and 5 μM of BAY 60-2770 were perfused into isolated rat hearts in a Langendorff system. After 10- or 30-min reperfusion with BAY 60-2770, cGMP and cAMP concentrations and PKG activation status were examined. Hearts were also perfused with 1 μM KT5823 or 100 μM 5-HD in conjunction with 5 nM Bay 60-2770 to evaluate the protective role of PKG. Mitochondrial oxidative stress was investigated under hypoxia-reoxygenation in H9c2 cells. In IR-injured rat hearts, BAY 60-2770 oral administration reduced infarct size by TTC staining and improved left ventricular function by echocardiography. Tissue samples from BAY 60-2770-perfused hearts had approximately two-fold higher cGMP levels. BAY 60-2770 increased PKG activity in the myocardium, and the reduced infarct area by BAY 60-2770 was abrogated by KT-5823 in isolated myocardium. In H9c2 cardiac myoblasts, hypoxia-reoxygenation-mediated mitochondrial ROS generation was diminished with BAY 60-2770 treatment, but was recovered by pretreatment with KT-5823. BAY 60-2770 demonstrated a protective effect against cardiac IR injury via mitoKATP opening and decreased mitoROS by PKG activation. BAY 60-2770 has a protective effect against cardiac IR injury via mitoKATP opening and decreased mitoROS by PKG activation. These results demonstrated that BAY 60-2770 may be used as a therapeutic agent for cardiac IR injury.

  9. LKB1 destabilizes microtubules in myoblasts and contributes to myoblast differentiation.

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    Isma Mian

    Full Text Available BACKGROUND: Skeletal muscle myoblast differentiation and fusion into multinucleate myotubes is associated with dramatic cytoskeletal changes. We find that microtubules in differentiated myotubes are highly stabilized, but premature microtubule stabilization blocks differentiation. Factors responsible for microtubule destabilization in myoblasts have not been identified. FINDINGS: We find that a transient decrease in microtubule stabilization early during myoblast differentiation precedes the ultimate microtubule stabilization seen in differentiated myotubes. We report a role for the serine-threonine kinase LKB1 in both microtubule destabilization and myoblast differentiation. LKB1 overexpression reduced microtubule elongation in a Nocodazole washout assay, and LKB1 RNAi increased it, showing LKB1 destabilizes microtubule assembly in myoblasts. LKB1 levels and activity increased during myoblast differentiation, along with activation of the known LKB1 substrates AMP-activated protein kinase (AMPK and microtubule affinity regulating kinases (MARKs. LKB1 overexpression accelerated differentiation, whereas RNAi impaired it. CONCLUSIONS: Reduced microtubule stability precedes myoblast differentiation and the associated ultimate microtubule stabilization seen in myotubes. LKB1 plays a positive role in microtubule destabilization in myoblasts and in myoblast differentiation. This work suggests a model by which LKB1-induced microtubule destabilization facilitates the cytoskeletal changes required for differentiation. Transient destabilization of microtubules might be a useful strategy for enhancing and/or synchronizing myoblast differentiation.

  10. Oxygen Modulates the Glutathione Peroxidase Activity during the L6 Myoblast Early Differentiation Process

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    Magdalena Hidalgo

    2014-01-01

    Full Text Available Aim: This work aims to study the regulation of the glutathione peroxidase and catalase activities in myoblasts from the L6 line exposed to 21%, 5% and 1% O2 during the cell differentiation. Material and Methods: Rat L6 myoblasts were grown in 1%, 5% or 21% O2 in the presence or absence of N-acetyl cysteine. The cell proliferation was evaluated by determining the doubling time and kinetics of cultures by counting cells. The cell differentiation was analyzed by determining the myogenic fusion index using antibodies against the myosin heavy chain. The glutathione peroxidase and catalase activities were assayed. The p110-PI3K/Thr308-Akt pathway was studied using western blotting. The oxidative status of the cells was carried out by determining TBARS. Results: 5% O2 improves the glutathione peroxidase activity, p110-PI3K/Thr308-Akt pathway and differentiation while 1% O2 alters all these parameters compared to 21% O2. NAC (0.5 mM can prevent the deleterious effects of hypoxia (1% O2 on the L6 myoblast proliferation and enhances the myoblast differentiation when exposed to 21% O2. TBARS are reduced in 5% O2 compared to both 21% and 1% O2. Conclusion: The glutathione peroxidase activity and p110-PI3K/Thr308-Akt are both modulated in the same way by oxygen.

  11. Inducing myoblast re-entry into the cell cycle: a potential mechanism for laser-enhanced skeletal muscle regeneration

    Science.gov (United States)

    Liu, T.; Fang, Y.; Zhang, C. P.; Chen, P.; Wang, C. Z.; Kang, H. X.; Shen, B. J.; Liang, J.; Fu, X. B.

    2014-09-01

    This study investigated the effect of low-level laser irradiation (LLLI) on the cell cycle and proliferative activity of cultured myoblasts, and sought to elucidate the possible cellular mechanism by which LLLI promotes the regeneration of skeletal muscle in vivo. Primary myoblasts isolated from rat hindlegs were irradiated with helium-neon laser light at different energy densities. Distributions of cell-cycle subpopulations and the expression of cell-cycle regulatory proteins in myoblasts were assessed using flow cytometric analysis and western blot assay. It was found that laser irradiation stimulated cell-cycle entry; induced the expression of cyclin A and cyclin D; and increased cell proliferation index and bromodeoxyuridine incorporation as compared to the unirradiated control cells, indicating LLLI augmented the number of proliferative myoblasts in the S phase and G2/M phase of the cell cycle. These results suggest that LLLI at certain fluxes and wavelengths could activate quiescent myoblasts, leading to cell division and facilitating new myofiber formation. This could contribute to the improvement of skeletal muscle regeneration following trauma and myopathic diseases.

  12. Modulation of apoptosis by sulforaphane is associated with PGC-1α stimulation and decreased oxidative stress in cardiac myoblasts.

    Science.gov (United States)

    Fernandes, Rafael O; Bonetto, Jéssica H P; Baregzay, Boran; de Castro, Alexandre L; Puukila, Stephanie; Forsyth, Heidi; Schenkel, Paulo C; Llesuy, Susana F; Brum, Ilma Simoni; Araujo, Alex Sander R; Khaper, Neelam; Belló-Klein, Adriane

    2015-03-01

    Sulforaphane is a naturally occurring isothiocyanate capable of stimulating cellular antioxidant defenses and inducing phase 2 detoxifying enzymes, which can protect cells against oxidative damage. Oxidative stress and apoptosis are intimately involved in the pathophysiology of cardiac diseases. Although sulforaphane is known for its anticancer benefits, its role in cardiac cells is just emerging. The aim of the present study was to investigate whether sulforaphane can modulate oxidative stress, apoptosis, and correlate with PGC-1α, a transcriptional cofactor involved in energy metabolism. H9c2 cardiac myoblasts were incubated with R-sulforaphane 5 µmol/L for 24 h. Cell viability, ANP gene expression, oxidative stress and apoptosis markers, and protein expression of PGC-1α were studied. In cells treated with sulforaphane, cellular viability increased (12 %) and ANP gene expression decreased (46 %) compared to control cells. Moreover, sulforaphane induced a significant increase in superoxide dismutase (103 %), catalase (101 %), and glutathione S-transferase (72 %) activity, reduced reactive oxygen species levels (15 %) and lipid peroxidation (65 %), as well as stimulated the expression of the cytoprotective enzyme heme oxygenase-1 (4-fold). Sulforaphane also promoted an increase in the expression of the anti-apoptotic protein Bcl-2 (60 %), decreasing the Bax/Bcl-2 ratio. Active Caspase 3\\7 and p-JNK/JNK were also reduced by sulforaphane, suggesting a reduction in apoptotic signaling. This was associated with an increased protein expression of PGC-1α (42 %). These results suggest that sulforaphane offers cytoprotection to cardiac cells by activating PGC1-α, reducing oxidative stress, and decreasing apoptosis signaling.

  13. Effect of Low Power Laser Irradiation on the Ability of Cell Growth and Myogenic Differentiation of Myoblasts Cultured In Vitro

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    Cui-Ping Zhang

    2014-01-01

    Full Text Available As a therapeutic modality, low power laser irradiation (LPLI has been used clinically in the treatment of skeletal muscle injuries and other myopathic conditions, but the cellular and molecular mechanisms attributed to this therapy were still unclear. Myoblasts are a type of myogenic stem cells quiescence in mature skeletal muscle fibers and are considered as the source cells during the regenerating process. The purpose of this paper was to investigate the effects of LPLI on the proliferation and myogenic differentiation of the cultured myoblasts and to find out the major candidates responsible for LPLI-induced muscle regeneration in vivo. In this study, primary rat myoblasts were exposed to helium-neon (He-Ne laser. Cell proliferation, differentiation, and the cellular responses to LPLI were monitored by using morphological observation and molecular biological methods. It was found that LPLI at a certain fluence could increase the cell growth potential for myoblasts and further induce more cells entering into S phase of the mitotic cycle as indicated by high levels of bromodeoxyuridine (BrdU incorporation, while at the same time inhibiting their in vitro differentiation and decreasing the expression of myogenic regulatory genes to a certain extent. Taken together, these results provide experimental evidence for the clinical applications of LPLI in regenerating skeletal muscle.

  14. Micropatterning topology on soft substrates affects myoblast proliferation and differentiation.

    Science.gov (United States)

    Zatti, Susi; Zoso, Alice; Serena, Elena; Luni, Camilla; Cimetta, Elisa; Elvassore, Nicola

    2012-02-07

    Micropatterning techniques and substrate engineering are becoming useful tools to investigate several aspects of cell-cell interaction biology. In this work, we rationally study how different micropatterning geometries can affect myoblast behavior in the early stage of in vitro myogenesis. Soft hydrogels with physiological elastic modulus (E = 15 kPa) were micropatterned in parallel lanes (100, 300, and 500 μm width) resulting in different local and global myoblast densities. Proliferation and differentiation into multinucleated myotubes were evaluated for murine and human myoblasts. Wider lanes showed a decrease in murine myoblast proliferation: (69 ± 8)% in 100 μm wide lanes compared to (39 ± 7)% in 500 μm lanes. Conversely, fusion index increased in wider lanes: from (46 ± 7)% to (66 ± 7)% for murine myoblasts, and from (15 ± 3)% to (36 ± 2)% for human primary myoblasts, using a patterning width of 100 and 500 μm, respectively. These results are consistent with both computational modeling data and conditioned medium experiments, which demonstrated that wider lanes favor the accumulation of endogenous secreted factors. Interestingly, human primary myoblast proliferation is not affected by patterning width, which may be because the high serum content of their culture medium overrides the effect of secreted factors. These data highlight the role of micropatterning in shaping the cellular niche through secreted factor accumulation, and are of paramount importance in rationally understanding myogenesis in vitro for the correct design of in vitro skeletal muscle models.

  15. Mast cell tryptase stimulates myoblast proliferation; a mechanism relying on protease-activated receptor-2 and cyclooxygenase-2

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    Côté Claude H

    2011-10-01

    Full Text Available Abstract Background Mast cells contribute to tissue repair in fibrous tissues by stimulating proliferation of fibroblasts through the release of tryptase which activates protease-activated receptor-2 (PAR-2. The possibility that a tryptase/PAR-2 signaling pathway exists in skeletal muscle cell has never been investigated. The aim of this study was to evaluate whether tryptase can stimulate myoblast proliferation and determine the downstream cascade. Methods Proliferation of L6 rat skeletal myoblasts stimulated with PAR-2 agonists (tryptase, trypsin and SLIGKV was assessed. The specificity of the tryptase effect was evaluated with a specific inhibitor, APC-366. Western blot analyses were used to evaluate the expression and functionality of PAR-2 receptor and to assess the expression of COX-2. COX-2 activity was evaluated with a commercial activity assay kit and by measurement of PGF2α production. Proliferation assays were also performed in presence of different prostaglandins (PGs. Results Tryptase increased L6 myoblast proliferation by 35% above control group and this effect was completely inhibited by APC-366. We confirmed the expression of PAR-2 receptor in vivo in skeletal muscle cells and in satellite cells and in vitro in L6 cells, where PAR-2 was found to be functional. Trypsin and SLIGKV increased L6 cells proliferation by 76% and 26% above control, respectively. COX-2 activity was increased following stimulation with PAR-2 agonist but its expression remained unchanged. Inhibition of COX-2 activity by NS-398 abolished the stimulation of cell proliferation induced by tryptase and trypsin. Finally, 15-deoxy-Δ-12,14-prostaglandin J2 (15Δ-PGJ2, a product of COX-2-derived prostaglandin D2, stimulated myoblast proliferation, but not PGE2 and PGF2α. Conclusions Taken together, our data show that tryptase can stimulate myoblast proliferation and this effect is part of a signaling cascade dependent on PAR-2 activation and on the downstream

  16. Stimulative Effects of Low Intensity He-Ne Laser Irradiation on the Proliferative Potential and Cell-Cycle Progression of Myoblasts in Culture

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    Cui-Ping Zhang

    2014-01-01

    Full Text Available Low intensity laser irradiation (LILI was found to promote the regeneration of skeletal muscle in vivo but the cellular mechanisms are not fully understood. Myoblasts, normally quiescent and inactivated in adult skeletal muscle, are a type of myogenic progenitor cells and considered as the major candidates responsible for muscle regeneration. The aim of the present study was to study the effect of LILI on the growth potential and cell-cycle progression of the cultured myoblasts. Primary myoblasts isolated from rat hind legs were cultured in nutrient-deficient medium for 36 hours and then irradiated by helium-neon laser at a certain energy density. Immunohistochemical and flow cytometric analysis revealed that laser irradiation could increase the expression of cellular proliferation marker and the amount of cell subpopulations in the proliferative phase as compared with the nonirradiated control group. Meanwhile, the expressions of cell-cycle regulatory proteins in the laser-treated myoblasts were markedly upregulated as compared to the unirradiated cells, indicating that LILI could promote the reentry of quiescent myoblasts into the cell division cycle. These results suggest that LILI at certain fluences could promote their proliferation, thus contributing to the skeletal muscle regeneration following trauma and myopathic diseases.

  17. Reversal of Myoblast Aging by Tocotrienol Rich Fraction Posttreatment

    Directory of Open Access Journals (Sweden)

    Jing Jye Lim

    2013-01-01

    Full Text Available Skeletal muscle satellite cells are heavily involved in the regeneration of skeletal muscle in response to the aging-related deterioration of the skeletal muscle mass, strength, and regenerative capacity, termed as sarcopenia. This study focused on the effect of tocotrienol rich fraction (TRF on regenerative capacity of myoblasts in stress-induced premature senescence (SIPS. The myoblasts was grouped as young control, SIPS-induced, TRF control, TRF pretreatment, and TRF posttreatment. Optimum dose of TRF, morphological observation, activity of senescence-associated β-galactosidase (SA-β-galactosidase, and cell proliferation were determined. 50 μg/mL TRF treatment exhibited the highest cell proliferation capacity. SIPS-induced myoblasts exhibit large flattened cells and prominent intermediate filaments (senescent-like morphology. The activity of SA-β-galactosidase was significantly increased, but the proliferation capacity was significantly reduced as compared to young control. The activity of SA-β-galactosidase was significantly reduced and cell proliferation was significantly increased in the posttreatment group whereas there was no significant difference in SA-β-galactosidase activity and proliferation capacity of pretreatment group as compared to SIPS-induced myoblasts. Based on the data, we hypothesized that TRF may reverse the myoblasts aging through replenishing the regenerative capacity of the cells. However, further investigation on the mechanism of TRF in reversing the myoblast aging is needed.

  18. Mechanical stimuli on C2C12 myoblasts affect myoblast differentiation, focal adhesion kinase phosphorylation and galectin-1 expression

    DEFF Research Database (Denmark)

    Grossi, Alberto Blak; Lametsch, Rene; Karlsson, Anders H

    2011-01-01

    Mechanical forces are crucial in the regulation of cell morphology and function. At the cellular level, these forces influence myoblast differentiation and fusion. In this study we applied mechanical stimuli to embryonic muscle cells using magnetic microbeads, a method shown to apply stress...... by mechanical stimulation including Galectin-1, Annexin III, and RhoGDI. In this study we demonstrate how the combination of this method of mechanical stimuli and proteomic analysis can be a powerful tool to detect proteins that are potentially interacting in biochemical pathways or complex cellular mechanisms...... during the process of myoblast differentiation. We determined an increase in expression and changes in cellular localization of Galectin-1, in mechanically stimulated myoblasts. A potential involvement of Galectin-1 in myoblast differentiation is presented....

  19. Phosphatidylserine directly and positively regulates fusion of myoblasts into myotubes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jaemin, E-mail: jmj1103@kirams.re.kr [Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720-1762 (United States); Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Conboy, Irina M., E-mail: iconboy@berkeley.edu [Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720-1762 (United States)

    2011-10-14

    Highlights: {yields} PS broadly and persistently trans-locates to the outer leaflet of plasma membrane during myoblast fusion into myotubes. {yields} Robust myotubes are formed when PS liposomes are added exogenously. {yields} PS increases the width of de novo myotubes and the numbers of myonuclei, but not the myotube length. {yields} Annexin V or PS antibody inhibits myotube formation by masking exposed PS. -- Abstract: Cell membrane consists of various lipids such as phosphatidylserine (PS), phosphatidylcholine (PC), and phosphatidylethanolamine (PE). Among them, PS is a molecular marker of apoptosis, because it is located to the inner leaflet of plasma membrane generally but it is moved to the outer leaflet during programmed cell death. The process of apoptosis has been implicated in the fusion of muscle progenitor cells, myoblasts, into myotubes. However, it remained unclear whether PS regulates muscle cell differentiation directly. In this paper, localization of PS to the outer leaflet of plasma membrane in proliferating primary myoblasts and during fusion of these myoblasts into myotubes is validated using Annexin V. Moreover, we show the presence of PS clusters at the cell-cell contact points, suggesting the importance of membrane ruffling and PS exposure for the myogenic cell fusion. Confirming this conclusion, experimentally constructed PS, but not PC liposomes dramatically enhance the formation of myotubes from myoblasts, thus demonstrating a direct positive effect of PS on the muscle cell fusion. In contrast, myoblasts exposed to PC liposomes produce long myotubes with low numbers of myonuclei. Moreover, pharmacological masking of PS on the myoblast surface inhibits fusion of these cells into myotubes in a dose-dependent manner.

  20. Myoblast transplantation for heart failure – From bench to bedside

    Directory of Open Access Journals (Sweden)

    Eugene K.W. Sim

    2005-07-01

    Full Text Available Heart failure causes morbidity and mortality. Cell transplantation using skeletal muscle myoblast is promising for myocardial repair as it can regenerate and repair the injury. Skeletal myoblasts are unipotent progenitor cells that can be expanded and genetically modified to deliver angiogenic cytokines and growth factors to encourage angiomyogenesis. Myoblast transplantation inhibits ventricular remodelling, decreases left ventricular diastolic dimension, increases myocardial wall thickness and minimizes global ventricular dilatation in animals. Ongoing trials with skeletal myoblast transplantation show improvement in perfusion and metabolic activity. Time constraints and the problem of generating autologous skeletal myoblasts for every patient can be overcome if allogeneic skeletal myoblasts from healthy young donors can be made available. Myoblast transplantation is confronted with the problem of donor cell survival post-transplantation. Its safety and feasibility have been documented during animal and phase I studies. The only serious postoperative adverse event related to the procedure was ventricular arrhythmias. The results of phase I studies are still preliminary. Endpoint measurements highlight improvement in quality of life, reduced nitroglycerine consumption, enhanced exercise tolerance, improvement in NYHA Class and wall motion by echocardiography, and significantly reduced perfusion defects. Future directions include concerted collaborative efforts, strict inclusion and exclusion criteria, better establishment of target population. Further work needs to be done on the ideal cell type, optimal number of cells and route of administration. The most suitable time for cell transplantation after ischemic injury and optimal mode of cell delivery are evaluated. The use of cell-based techniques to assist with cardiac regeneration holds promise for the treatment of heart failure.

  1. Isolation of human foetal myoblasts and its application for microencapsulation.

    Science.gov (United States)

    Li, Anna Aihua; Bourgeois, Jacqueline; Potter, Murray; Chang, Patricia L

    2008-01-01

    Foetal cells secrete more growth factors, generate less immune response, grow and proliferate better than adult cells. These characteristics make them desirable for recombinant modification and use in microencapsulated cellular gene therapeutics. We have established a system in vitro to obtain a pure population of primary human foetal myoblasts under several rounds of selection with non-collagen coated plates and identified by desmin staining. These primary myoblasts presented good proliferation ability and better differentiation characteristics in monolayer and after microencapsulation compared to murine myoblast C2C12 cells based on creatine phosphokinase (CPK), major histocompatibility complex (MHC) and multi-nucleated myotubule determination. The lifespan of primary myoblasts was 70 population doublings before entering into senescent state, with a population time of 18-24 hrs. Hence, we have developed a protocol for isolating human foetal primary myoblasts with excellent differentiation potential and robust growth and longevity. They should be useful for cell-based therapy in human clinical applications with microencapsulation technology.

  2. Regulation of myoblast differentiation by metabolic perturbations induced by metformin.

    Directory of Open Access Journals (Sweden)

    Theodora Pavlidou

    Full Text Available The metabolic perturbation caused by calorie restriction enhances muscle repair by playing a critical role in regulating satellite cell availability and activity in the muscles of young and old mice. To clarify the underlying mechanisms we asked whether myoblast replication and differentiation are affected by metformin, a calorie restriction-mimicking drug. C2C12, a mouse myoblast cell line, readily differentiate in vitro and fuse to form myotubes. However, when incubated with metformin, C2C12 slow their replication and do not differentiate. Interestingly, lower doses of metformin promote myogenic differentiation. We observe that metformin treatment modulates the expression of cyclins and cyclin inhibitors thereby inducing a cell cycle perturbation that causes a delay in the G2/M transition. The effect of metformin treatment is reversible since after drug withdrawal, myoblasts can re-enter the cell cycle and/or differentiate, depending on culture conditions. Myoblasts cultured under metformin treatment fail to up-regulate MyoD and p21cip1, a key step in cell cycle exit and terminal differentiation. Although the details of the molecular mechanisms underlying the effect of the drug on myoblasts still need to be clarified, we propose that metformin negatively affects myogenic differentiation by inhibiting irreversible exit from the cell cycle through reduction of MyoD and p21cip1 levels.

  3. miR-145a-5p Promotes Myoblast Differentiation

    Directory of Open Access Journals (Sweden)

    Jingjing Du

    2016-01-01

    Full Text Available MicroRNAs are a class of 18–22-nucleotide noncoding RNAs that posttranscriptionally regulate gene expression and have been shown to play an important role during myoblast differentiation. In this study, we found that the expression of miR-145a-5p was gradually increased during C2C12 myoblast differentiation, and miR-145a-5p inhibitors or mimics significantly suppressed or promoted the relative expression of specific myogenesis related marker genes. Moreover, overexpression or inhibition of miR-145a-5p enhanced or repressed the expression of some special genes involved in the endogenous Wnt signaling pathway during C2C12 myoblast differentiation, including Wnt5a, LRP5, Axin2, and β-catenin. These results indicated that miR-145a-5p might be considered as a new myogenic differentiation-associated microRNA that can promote C2C12 myoblast differentiation by enhancing genes related to myoblasts differentiation.

  4. Isolation of human foetal myoblasts and its application for microencapsulation

    Science.gov (United States)

    Li, Anna Aihua; Bourgeois, Jacqueline; Potter, Murray; Chang, Patricia L

    2008-01-01

    Abstract Foetal cells secrete more growth factors, generate less immune response, grow and proliferate better than adult cells. These characteristics make them desirable for recombinant modification and use in microencapsulated cellular gene therapeutics. We have established a system in vitro to obtain a pure population of primary human foetal myoblasts under several rounds of selection with non-collagen coated plates and identified by desmin staining. These primary myoblasts presented good proliferation ability and better differentiation characteristics in monolayer and after microencapsulation compared to murine myoblast C2C12 cells based on creatine phosphokinase (CPK), major histocompatibility complex (MHC) and multi-nucleated myotubule determination. The lifespan of primary myoblasts was 70 population doublings before entering into senescent state, with a population time of 18–24 hrs. Hence, we have developed a protocol for isolating human foetal primary myoblasts with excellent differentiation potential and robust growth and longevity. They should be useful for cell-based therapy in human clinical applications with microencapsulation technology. PMID:18366454

  5. File list: InP.Myo.20.AllAg.Myoblasts [Chip-atlas[Archive

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  11. File list: Oth.Myo.10.AllAg.Myoblasts [Chip-atlas[Archive

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  12. File list: InP.Myo.50.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: Unc.Myo.10.AllAg.Myoblasts [Chip-atlas[Archive

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    Lifescience Database Archive (English)

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  16. File list: InP.Myo.20.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  18. File list: His.Myo.20.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  20. File list: InP.Myo.05.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. File list: InP.Myo.50.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  2. File list: ALL.Myo.05.AllAg.Myoblasts [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  3. The critical role of myostatin in differentiation of sheep myoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chenxi [College of Life Science and Technology, Xinjiang University, Urumqi (China); Xinjiang Laboratory of Animal Biotechnology, Urumqi (China); Li, Wenrong; Zhang, Xuemei; Zhang, Ning; He, Sangang; Huang, Juncheng [Xinjiang Laboratory of Animal Biotechnology, Urumqi (China); Laboratory of Grass-fed Animal Genetics, Breeding and Reproduction of Ministry of Agriculture, Urumqi (China); Animal Biotechnological Research Center, Xinjiang Academy of Animal Science, Urumqi (China); Ge, Yubin [The State Engineering Laboratory of AIDS Vaccine, College of Life Science, Jilin University, Changchun (China); Liu, Mingjun, E-mail: xjlmj2004@yahoo.com.cn [Xinjiang Laboratory of Animal Biotechnology, Urumqi (China); Laboratory of Grass-fed Animal Genetics, Breeding and Reproduction of Ministry of Agriculture, Urumqi (China); Animal Biotechnological Research Center, Xinjiang Academy of Animal Science, Urumqi (China)

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer Identification of the effective and specific shRNA to knockdown MSTN. Black-Right-Pointing-Pointer Overexpression of MSTN reversibly suppressed myogenic differentiation. Black-Right-Pointing-Pointer shRNA knockdown of endogenous MSTN promoted ovine myoblast differentiation. Black-Right-Pointing-Pointer MSTN inhibits myogenic differentiation through down-regulation of MyoD and Myogenin and up-regulation of Smad3. Black-Right-Pointing-Pointer Provides a promise for the generation of transgenic sheep to improve meat productivity. -- Abstract: Myostatin [MSTN, also known as growth differentiation factor 8 (GDF8)], is an inhibitor of skeletal muscle growth. Blockade of MSTN function has been reported to result in increased muscle mass in mice. However, its role in myoblast differentiation in farm animals has not been determined. In the present study, we sought to determine the role of MSTN in the differentiation of primary sheep myoblasts. We found that ectopic overexpression of MSTN resulted in lower fusion index in sheep myoblasts, which indicated the repression of myoblast differentiation. This phenotypic change was reversed by shRNA knockdown of the ectopically expressed MSTN in the cells. In contrast, shRNA knockdown of the endogenous MSTN resulted in induction of myogenic differentiation. Additional studies revealed that the induction of differentiation by knocking down the ectopically or endogenously expressed MSTN was accompanied by up-regulation of MyoD and myogenin, and down-regulation of Smad3. Our results demonstrate that MSTN plays critical role in myoblast differentiation in sheep, analogous to that in mice. This study also suggests that shRNA knockdown of MSTN could be a potentially promising approach to improve sheep muscle growth, so as to increase meat productivity.

  4. Nilotinib impairs skeletal myogenesis by increasing myoblast proliferation

    Directory of Open Access Journals (Sweden)

    Osvaldo Contreras

    2018-02-01

    Full Text Available Abstract Background Tyrosine kinase inhibitors (TKIs are effective therapies with demonstrated antineoplastic activity. Nilotinib is a second-generation FDA-approved TKI designed to overcome Imatinib resistance and intolerance in patients with chronic myelogenous leukemia (CML. Interestingly, TKIs have also been shown to be an efficient treatment for several non-malignant disorders such fibrotic diseases, including those affecting skeletal muscles. Methods We investigated the role of Nilotinib on skeletal myogenesis using the well-established C2C12 myoblast cell line. We evaluated the impact of Nilotinib during the time course of skeletal myogenesis. We compared the effect of Nilotinib with the well-known p38 MAPK inhibitor SB203580. MEK1/2 UO126 and PI3K/AKT LY294002 inhibitors were used to identify the signaling pathways involved in Nilotinib-related effects on myoblast. Adult primary myoblasts were also used to corroborate the inhibition of myoblasts fusion and myotube-nuclei positioning by Nilotinib. Results We found that Nilotinib inhibited myogenic differentiation, reducing the number of myogenin-positive myoblasts and decreasing myogenin and MyoD expression. Furthermore, Nilotinib-mediated anti-myogenic effects impair myotube formation, myosin heavy chain expression, and compromise myotube-nuclei positioning. In addition, we found that p38 MAPK is a new off-target protein of Nilotinib, which causes inhibition of p38 phosphorylation in a similar manner as the well-characterized p38 inhibitor SB203580. Nilotinib induces the activation of ERK1/2 and AKT on myoblasts but not in myotubes. We also found that Nilotinib stimulates myoblast proliferation, a process dependent on ERK1/2 and AKT activation. Conclusions Our findings suggest that Nilotinib may have important negative effects on muscle homeostasis, inhibiting myogenic differentiation but stimulating myoblasts proliferation. Additionally, we found that Nilotinib stimulates the activation

  5. Modelling human myoblasts survival upon xenotransplantation into immunodeficient mouse muscle.

    Science.gov (United States)

    Praud, Christophe; Vauchez, Karine; Zongo, Pascal; Vilquin, Jean-Thomas

    2018-03-15

    Cell transplantation has been challenged in several clinical indications of genetic or acquired muscular diseases, but therapeutic success were mitigated. To understand and improve the yields of tissue regeneration, we aimed at modelling the fate of CD56-positive human myoblasts after transplantation. Using immunodeficient severe combined immunodeficiency (SCID) mice as recipients, we assessed the survival, integration and satellite cell niche occupancy of human myoblasts by a triple immunohistochemical labelling of laminin, dystrophin and human lamin A/C. The counts were integrated into a classical mathematical decline equation. After injection, human cells were essentially located in the endomysium, then they disappeared progressively from D0 to D28. The final number of integrated human nuclei was grossly determined at D2 after injection, suggesting that no more efficient fusion between donor myoblasts and host fibers occurs after the resolution of the local damages created by needle insertion. Almost 1% of implanted human cells occupied a satellite-like cell niche. Our mathematical model validated by histological counting provided a reliable quantitative estimate of human myoblast survival and/or incorporation into SCID muscle fibers. Informations brought by histological labelling and this mathematical model are complementary. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Hepatocyte growth factor-transfected skeletal myoblasts to limit the development of postinfarction heart failure.

    Science.gov (United States)

    Poppe, Annika; Golsong, Peter; Blumenthal, Britta; von Wattenwyl, Robert; Blanke, Philipp; Beyersdorf, Friedhelm; Schlensak, Christian; Siepe, Matthias

    2012-03-01

    Stem cells transplanted to an injured heart affect the host myocardium indirectly. The cytokine hepatocyte growth factor (HGF) may play a key role in this paracrine activity. We hypothesized that HGF-overexpressing stem cells would restore cardiac function after myocardial infarction (MI). Because there is a high rate of cell death when injecting the cells intramyocardially, we used scaffold-based cell transfer. Skeletal myoblasts (SkMs) were isolated and expanded from newborn Lewis rats. Cells were transfected with pcDNA3-huHGF and seeded on polyurethane (PU) scaffolds or diluted in medium for cell injection. The seeded scaffolds were transplanted in rats two weeks after MI (group: PU-HGF-SkM) or the infection solution was intramyocardially injected (group: Inj-HGF-SkM). Two groups (Inj-SkM and PU-SkM) have been prepared with untransfected cells and sham group without any cell therapy served as control (n = 10 each group). At the beginning of treatment (baseline) and six weeks later, hemodynamic parameters were assessed. At the end of the study, histological analysis was employed. In sham animals we detected a decrease in systolic and diastolic function during the observation time. Treatment with untransfected myoblasts did not lead to any significant changes in hemodynamic parameters between the intervention and six weeks later. In group PU-HGF-SkM, systolic parameters like dP/dt(max), dP/dt(min) and isovolumic contraction improved significantly from baseline to study end. Some diastolic parameters were inferior as compared to baseline (SB-Ked, pressure half time [PHT], Tau). In group Inj-HGF-SkM, only PHT was impaired as compared to preinterventional values. Histological analysis showed significantly more capillaries in the infarction border zone in groups PU-HGF-SkM than in sham and Inj-SkM group. The infarction size was not affected by the therapy. Transplanting HGF-transfected myoblasts after MI can limit the development of ventricular dysfunction

  7. Marked heterogeneity in growth characteristics of myoblast clonal cultures and myoblast mixed cultures obtained from the same individual

    NARCIS (Netherlands)

    Maier, Andrea B.; Cohen, Ron; Blom, Joke; Van Heemst, Diana; Westendorp, Rudi G.J.

    Background: Sarcopenia is defined as an age-related decrease in skeletal muscle mass and function while adjacent satellite cells are unable to compensate for this loss. However, myoblast cultures can be established even in the presence of sarcopenia. Objective: It is yet unknown whether satellite

  8. Neural cell adhesion molecule is a cardioprotective factor up-regulated by metabolic stress.

    OpenAIRE

    Nagao, Kazuya; Ono, Koh; Iwanaga, Yoshitaka; Tamaki, Yodo; Kojima, Yoji; Horie, Takahiro; Nishi, Hitoo; Kinoshita, Minako; Kuwabara, Yasuhide; Hasegawa, Koji; Kita, Toru; KIMURA, TAKESHI

    2010-01-01

    Screening for cell surface proteins up-regulated under stress conditions may lead to the identification of new therapeutic targets. To search for genes whose expression was enhanced by treatment with oligomycin, a mitochondrial-F(0)F(1) ATP synthase inhibitor, signal sequence trapping was performed in H9C2 rat cardiac myoblasts. One of the genes identified was that for neural cell adhesion molecule (NCAM, CD56), a major regulator of development, cell survival, migration, and neurite outgrowth...

  9. Engineering skeletal muscle tissues from murine myoblast progenitor cells and application of electrical stimulation.

    Science.gov (United States)

    van der Schaft, Daisy W J; van Spreeuwel, Ariane C C; Boonen, Kristel J M; Langelaan, Marloes L P; Bouten, Carlijn V C; Baaijens, Frank P T

    2013-03-19

    Engineered muscle tissues can be used for several different purposes, which include the production of tissues for use as a disease model in vitro, e.g. to study pressure ulcers, for regenerative medicine and as a meat alternative (1). The first reported 3D muscle constructs have been made many years ago and pioneers in the field are Vandenburgh and colleagues (2,3). Advances made in muscle tissue engineering are not only the result from the vast gain in knowledge of biochemical factors, stem cells and progenitor cells, but are in particular based on insights gained by researchers that physical factors play essential roles in the control of cell behavior and tissue development. State-of-the-art engineered muscle constructs currently consist of cell-populated hydrogel constructs. In our lab these generally consist of murine myoblast progenitor cells, isolated from murine hind limb muscles or a murine myoblast cell line C2C12, mixed with a mixture of collagen/Matrigel and plated between two anchoring points, mimicking the muscle ligaments. Other cells may be considered as well, e.g. alternative cell lines such as L6 rat myoblasts (4), neonatal muscle derived progenitor cells (5), cells derived from adult muscle tissues from other species such as human (6) or even induced pluripotent stem cells (iPS cells) (7). Cell contractility causes alignment of the cells along the long axis of the construct (8,9) and differentiation of the muscle progenitor cells after approximately one week of culture. Moreover, the application of electrical stimulation can enhance the process of differentiation to some extent (8). Because of its limited size (8 x 2 x 0.5 mm) the complete tissue can be analyzed using confocal microscopy to monitor e.g. viability, differentiation and cell alignment. Depending on the specific application the requirements for the engineered muscle tissue will vary; e.g. use for regenerative medicine requires the up scaling of tissue size and vascularization, while

  10. CD36 is required for myoblast fusion during myogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung-Yoon [Department of Biochemistry, College of Medicine, Dongguk University and Medical Institute of Dongguk University, Gyeongju 780-714 (Korea, Republic of); Yun, Youngeun [Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Kim, In-San, E-mail: iskim@knu.ac.kr [Department of Biochemistry and Cell Biology, Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Biomedical Research Institute, Korea Institute Science and Technology, Seoul (Korea, Republic of)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer CD36 expression was induced during myogenic differentiation. Black-Right-Pointing-Pointer CD36 expression was localized in multinucleated myotubes. Black-Right-Pointing-Pointer The expression of myogenic markers is attenuated in CD36 knockdown C2C12 cells. Black-Right-Pointing-Pointer Knockdown of CD36 significantly inhibited myotube formation during differentiation. -- Abstract: Recently, CD36 has been found to be involved in the cytokine-induced fusion of macrophage. Myoblast fusion to form multinucleated myotubes is required for myogenesis and muscle regeneration. Because a search of gene expression database revealed the attenuation of CD36 expression in the muscles of muscular dystrophy patients, the possibility that CD36 could be required for myoblast fusion was investigated. CD36 expression was markedly up-regulated during myoblast differentiation and localized in multinucleated myotubes. Knockdown of endogenous CD36 significantly decreased the expression of myogenic markers as well as myotube formation. These results support the notion that CD36 plays an important role in cell fusion during myogenic differentiation. Our finding will aid the elucidation of the common mechanism governing cell-to-cell fusion in various fusion models.

  11. Interactions between Skeletal Muscle Myoblasts and their Extracellular Matrix Revealed by a Serum Free Culture System.

    Science.gov (United States)

    Chaturvedi, Vishal; Dye, Danielle E; Kinnear, Beverley F; van Kuppevelt, Toin H; Grounds, Miranda D; Coombe, Deirdre R

    2015-01-01

    Decellularisation of skeletal muscle provides a system to study the interactions of myoblasts with muscle extracellular matrix (ECM). This study describes the efficient decellularisation of quadriceps muscle with the retention of matrix components and the use of this matrix for myoblast proliferation and differentiation under serum free culture conditions. Three decellularisation approaches were examined; the most effective was phospholipase A2 treatment, which removed cellular material while maximizing the retention of ECM components. Decellularised muscle matrices were then solubilized and used as substrates for C2C12 mouse myoblast serum free cultures. The muscle matrix supported myoblast proliferation and differentiation equally as well as collagen and fibronectin. Immunofluorescence analyses revealed that myoblasts seeded on muscle matrix and fibronectin differentiated to form long, well-aligned myotubes, while myoblasts seeded on collagen were less organized. qPCR analyses showed a time dependent increase in genes involved in skeletal muscle differentiation and suggested that muscle-derived matrix may stimulate an increased rate of differentiation compared to collagen and fibronectin. Decellularized whole muscle three-dimensional scaffolds also supported cell adhesion and spreading, with myoblasts aligning along specific tracts of matrix proteins within the scaffolds. Thus, under serum free conditions, intact acellular muscle matrices provided cues to direct myoblast adhesion and migration. In addition, myoblasts were shown to rapidly secrete and organise their own matrix glycoproteins to create a localized ECM microenvironment. This serum free culture system has revealed that the correct muscle ECM facilitates more rapid cell organisation and differentiation than single matrix glycoprotein substrates.

  12. Transplanted myoblasts can migrate several millimeters to fuse with damaged myofibers in nonhuman primate skeletal muscle.

    Science.gov (United States)

    Skuk, Daniel; Goulet, Marlyne; Tremblay, Jacques P

    2011-09-01

    A major restriction of the intramuscular transplantation of myoblasts is that the grafted cells fuse mostly with myofibers along the injection trajectories. This has been attributed to a "lack of migration ability" of the grafted myoblasts. It has been assumed that grafted myoblasts remain motionless in the sites of delivery and fuse only with myofibers with which they come into contact. In the present study, we analyzed this phenomenon in 17 cynomolgus monkeys. We found that intramuscularly injected myoblasts within 1 hour after their injection are mainly located in the perimysium and not distributed along the injection trajectories. This suggested that the grafted myoblasts later migrate from the perimysium to fuse with myofibers that are damaged by the injections. Therefore, we analyzed whether β-galactosidase-labeled myoblasts injected subcutaneously over skeletal muscles migrate in needle-damaged and nondamaged muscle regions. We observed that grafted myoblasts migrated up to 1cm in depth from the muscle surface into the muscles, although they seemingly fused mainly with damaged myofibers. Our findings suggest that myoblast transplantation is not necessarily restricted bya "lack of migration ability" of the grafted cells but by the fact that myoblasts fuse with regenerating myofibers and not with undamaged myofibers.

  13. Combination of Nigella sativa with Glycyrrhiza glabra and Zingiber officinale augments their protective effects on doxorubicin-induced toxicity in h9c2 cells

    Directory of Open Access Journals (Sweden)

    Azar Hosseini

    2015-12-01

    Conclusion: All of the extracts have some protective effects against DOX-induced toxicity in cardiomyocytes with similar efficacies, but with different potencies. However, NGZ produced much higher protective effect via reducing oxidative stress and inhibiting of apoptotic induction processes. Further investigations are needed to determine the effects of NGZ on DOX chemotherapy.  

  14. Canstatin inhibits hypoxia-induced apoptosis through activation of integrin/focal adhesion kinase/Akt signaling pathway in H9c2 cardiomyoblasts

    National Research Council Canada - National Science Library

    Kanazawa, Hiroki; Imoto, Keisuke; Okada, Muneyoshi; Yamawaki, Hideyuki

    2017-01-01

    .... Cell counting assay was performed to determine a cell viability. Western blotting was performed to detect expression of cleaved casepase-3 and phosphorylation of focal adhesion kinase (FAK) and Akt...

  15. Acetylcholine Attenuated TNF-α-Induced Apoptosis in H9c2 Cells: Role of Calpain and the p38-MAPK Pathway

    Directory of Open Access Journals (Sweden)

    Ming Zhao

    2015-07-01

    Full Text Available Background: Previous studies have shown that inflammation is associated with excessive activation of calpains. Acetylcholine (ACh has been reported to inhibit pro-inflammatory cytokine release and protect against cardiomyocyte injury. However, there is no direct evidence regarding whether ACh can regulate calpains to exert cardioprotection. To this end, we investigated the effect of ACh on tumour necrosis factor alpha (TNF-α-induced cardiomyocyte injury and further explored the underlying mechanism. Methods: Flow cytometry and transmission electron microscopy were performed to evaluate apoptosis and cellular ultrastructure. Western blotting was performed to assess changes in protein expression. siRNA was employed to silence specific proteins. Results: TNF-α treatment increased the expression of cleaved caspase-3, calpain-1 and p38-mitogen-activated protein kinase (p38-MAPK. The calpain inhibitor PD150606 and the p38-MAPK inhibitor SB203580 inhibited apoptosis induced by TNF-α. Moreover, SB203580 decreased the expression and activity of calpain-1, possibly related to the up-regulation of calpastatin. ACh significantly inhibited TNF-α-induced cell apoptosis, as evidenced by decreases in caspase-3 cleavage, p38-MAPK phosphorylation, and calpain-1 expression and activity as well as increases in calpastatin expression. These beneficial effects of ACh were abolished by atropine or M2AChR siRNA. Conclusion: Our results suggest that ACh ameliorated TNF-α-induced calpain activation by decreasing p38-MAPK phosphorylation and enhancing calpastatin expression, indicating that calpain may be an important link between inflammatory factors and myocardial cell apoptosis.

  16. Sirtuin-3 (SIRT3) protein attenuates doxorubicin-induced oxidative stress and improves mitochondrial respiration in H9c2 cardiomyocytes

    Science.gov (United States)

    Doxorubicin (DOX) is a chemotherapeutic agent effective in the treatment of many cancers. However, cardiac dysfunction caused by DOX limits its clinical use. DOX is believed to be harmful to cardiomyocytes by interfering with the mitochondrial phospholipid cardiolipin and causing inefficient electro...

  17. Interactions between Skeletal Muscle Myoblasts and their Extracellular Matrix Revealed by a Serum Free Culture System

    NARCIS (Netherlands)

    Chaturvedi, V.; Dye, D.E.; Kinnear, B.F.; Kuppevelt, T.H. van; Grounds, M.D.; Coombe, D.R.

    2015-01-01

    Decellularisation of skeletal muscle provides a system to study the interactions of myoblasts with muscle extracellular matrix (ECM). This study describes the efficient decellularisation of quadriceps muscle with the retention of matrix components and the use of this matrix for myoblast

  18. Anti-inflammatory effects of triptolide improve left ventricular function in a rat model of diabetic cardiomyopathy

    Science.gov (United States)

    2013-01-01

    Aims Given the importance of inflammation in the onset and progression of diabetic cardiomyopathy, we investigated the potential protective effects of triptolide, an anti-inflammatory agent, in streptozotocin-induced diabetic rat model and in H9c2 rat cardiac cells exposed to high glucose. Methods and results Diabetic rats were treated with triptolide (100, 200, or 400 μg/kg/day respectively) for 6 weeks. At the end of this study, after cardiac function measurements were performed, rats were sacrificed and their hearts were harvested for further histologic and molecular biologic analysis. Enhanced activity and expression of nuclear factor-kappaB (NF-κB) p65 in diabetic hearts were associated with increased inflammatory response, as demonstrated by increased pro-inflammatory cytokines, cell adhesion molecules and invading inflammatory cells, as well as increased fibrosis, in line with impaired left ventricular function. Triptolide attenuated these morpho-functional alterations. Furthermore, triptolide (20 ng/ml) also attenuated high glucose-induced inflammation in H9c2 rat cardiac cells. Conclusion Our data demonstrate that anti-inflammatory effects of triptolide involving the NF-κB signaling pathway can improve left ventricular function under diabetic conditions, suggesting triptolide treatment might be beneficial in diabetic cardiomyopathy. PMID:23530831

  19. Genome-wide examination of myoblast cell cycle withdrawal duringdifferentiation

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xun; Collier, John Michael; Hlaing, Myint; Zhang, Leanne; Delshad, Elizabeth H.; Bristow, James; Bernstein, Harold S.

    2002-12-02

    Skeletal and cardiac myocytes cease division within weeks of birth. Although skeletal muscle retains limited capacity for regeneration through recruitment of satellite cells, resident populations of adult myocardial stem cells have not been identified. Because cell cycle withdrawal accompanies myocyte differentiation, we hypothesized that C2C12 cells, a mouse myoblast cell line previously used to characterize myocyte differentiation, also would provide a model for studying cell cycle withdrawal during differentiation. C2C12 cells were differentiated in culture medium containing horse serum and harvested at various time points to characterize the expression profiles of known cell cycle and myogenic regulatory factors by immunoblot analysis. BrdU incorporation decreased dramatically in confluent cultures 48 hr after addition of horse serum, as cells started to form myotubes. This finding was preceded by up-regulation of MyoD, followed by myogenin, and activation of Bcl-2. Cyclin D1 was expressed in proliferating cultures and became undetectable in cultures containing 40 percent fused myotubes, as levels of p21(WAF1/Cip1) increased and alpha-actin became detectable. Because C2C12 myoblasts withdraw from the cell cycle during myocyte differentiation following a course that recapitulates this process in vivo, we performed a genome-wide screen to identify other gene products involved in this process. Using microarrays containing approximately 10,000 minimally redundant mouse sequences that map to the UniGene database of the National Center for Biotechnology Information, we compared gene expression profiles between proliferating, differentiating, and differentiated C2C12 cells and verified candidate genes demonstrating differential expression by RT-PCR. Cluster analysis of differentially expressed genes revealed groups of gene products involved in cell cycle withdrawal, muscle differentiation, and apoptosis. In addition, we identified several genes, including DDAH2 and Ly

  20. Characterization of human myoblast cultures for tissue engineering.

    Science.gov (United States)

    Stern-Straeter, Jens; Bran, Gregor; Riedel, Frank; Sauter, Alexander; Hörmann, Karl; Goessler, Ulrich Reinhart

    2008-01-01

    Skeletal muscle tissue engineering, a promising specialty, aims at the reconstruction of skeletal muscle loss. In vitro tissue engineering attempts to achieve this goal by creating differentiated, functional muscle tissue through a process in which stem cells are extracted from the patient, e.g. by muscle biopsies, expanded and differentiated in a controlled environment, and subsequently re-implanted. A prerequisite for this undertaking is the ability to cultivate and differentiate human skeletal muscle cell cultures. Evidently, optimal culture conditions must be investigated for later clinical utilization. We therefore analysed the proliferation of human cells in different environments and evaluated the differentiation potential of different culture media. It was shown that human myoblasts have a higher rate of proliferation in the alamarBlue assay when cultured on gelatin-coated culture flasks rather than polystyrene-coated flasks. We also demonstrated that myoblasts treated with a culture medium with a high concentration of growth factors [growth medium (GM)] showed a higher proliferation compared to cultures treated with a culture medium with lower amounts of growth factors [differentiation medium (DM)]. Differentiation of human myoblast cell cultures treated with GM and DM was analysed until day 16 and myogenesis was verified by expression of MyoD, myogenin, alpha-sarcomeric actin and myosin heavy chain by semi-quantitative RT-PCR. Immunohistochemical staining for desmin, Myf-5 and alpha-sarcomeric actin was performed to verify the myogenic phenotype of extracted satellite cells and to prove the maturation of cells. Cultures treated with DM showed positive staining for alpha-sarcomeric actin. Notably, markers of differentiation were also detected in cultures treated with GM, but there was no formation of myotubes. In the enzymatic assay of creatine phosphokinase, cultures treated with DM showed a higher activity, evidencing a higher degree of differentiation

  1. Hypoxia induces adipogenic differentitation of myoblastic cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Itoigawa, Yoshiaki [Tohoku University School of Medicine, Sendai (Japan); Juntendo University School of Medicine, Tokyo (Japan); Kishimoto, Koshi N., E-mail: kishimoto@med.tohoku.ac.jp [Tohoku University School of Medicine, Sendai (Japan); Okuno, Hiroshi; Sano, Hirotaka [Tohoku University School of Medicine, Sendai (Japan); Kaneko, Kazuo [Juntendo University School of Medicine, Tokyo (Japan); Itoi, Eiji [Tohoku University School of Medicine, Sendai (Japan)

    2010-09-03

    Research highlights: {yields} C2C12 and G8 myogenic cell lines treated by hypoxia differentiate into adipocytes. {yields} The expression of C/EBP{beta}, {alpha} and PPAR{gamma} were increased under hypoxia. {yields} Myogenic differentiation of C2C12 was inhibited under hypoxia. -- Abstract: Muscle atrophy usually accompanies fat accumulation in the muscle. In such atrophic conditions as back muscles of kyphotic spine and the rotator cuff muscles with torn tendons, blood flow might be diminished. It is known that hypoxia causes trans-differentiation of mesenchymal stem cells derived from bone marrow into adipocytes. However, it has not been elucidated yet if hypoxia turned myoblasts into adipocytes. We investigated adipogenesis in C2C12 and G8 murine myogenic cell line treated by hypoxia. Cells were also treated with the cocktail of insulin, dexamethasone and IBMX (MDI), which has been known to inhibit Wnt signaling and promote adipogenesis. Adipogenic differentiation was seen in both hypoxia and MDI. Adipogenic marker gene expression was assessed in C2C12. CCAAT/enhancer-binding protein (C/EBP) {beta}, {alpha} and peroxisome proliferator activating receptor (PPAR) {gamma} were increased by both hypoxia and MDI. The expression profile of Wnt10b was different between hypoxia and MDI. The mechanism for adipogenesis of myoblasts in hypoxia might be regulated by different mechanism than the modification of Wnt signaling.

  2. Sulfur dioxide restores calcium homeostasis disturbance in rat with isoproterenol-induced myocardial injury.

    Science.gov (United States)

    Chen, Shanshan; Du, Junbao; Liang, Yinfang; Zhang, Rongyuan; Tang, Chaoshu; Jin, Hongfang

    2012-09-01

    sulfur dioxide (SO₂) could relieve isoproterenol (ISO)-induced myocardial injury, while the mechanism is unclear. This study aims to explore whether the protective effect of SO₂ on ISO-induced myocardial injury was mediated by the restoration of calcium homeostasis disturbance in cardiomyocyte. Rats were randomly divided into four groups: ISO group, ISO+SO₂ group, control group and SO₂ group. Content of Ca²⁺ in H9c2 cells was assayed using confocal microscope, and cardiac function parameters were measured by echocardiography. Plasma biochemical values and myocardial ultra-structure changes were measured. Meanwhile, the activity, protein and gene levels of sarcoplasmic reticulum Ca²⁺ ATPase (SERCA), and protein and phosphorylation of phospholamban (PLN) were detected. We found SO₂ derivatives could restore the decreased cardiac function, the abnormal lactate dehydrogenase, creatine kinase, alpha-hydroxybutyrate dehydrogenase, potassium, calcium, blood urea nitrogen and the damaged myocardial ultra-structure in rats, and regulate the increased Ca²⁺ content in H9c2 induced by ISO. In addition, compared with ISO group, the decreased activities, protein and mRNA level of SERCA, as well as the decreased protein phosphorylation level of PLN in myocardial tissues were increased in ISO+SO₂ group. SO₂ derivatives might relieve calcium overload in association with the upregulating expression of SERCA and p-PLN/PLN by myocardial tissues in rats with ISO-induced myocardial injury.

  3. Myoblast replication is reduced in the IUGR fetus despite maintained proliferative capacity in vitro.

    Science.gov (United States)

    Soto, Susan M; Blake, Amy C; Wesolowski, Stephanie R; Rozance, Paul J; Barthel, Kristen B; Gao, Bifeng; Hetrick, Byron; McCurdy, Carrie E; Garza, Natalia G; Hay, William W; Leinwand, Leslie A; Friedman, Jacob E; Brown, Laura D

    2017-03-01

    Adults who were affected by intrauterine growth restriction (IUGR) suffer from reductions in muscle mass and insulin resistance, suggesting muscle growth may be restricted by molecular events that occur during fetal development. To explore the basis of restricted fetal muscle growth, we used a sheep model of progressive placental insufficiency-induced IUGR to assess myoblast proliferation within intact skeletal muscle in vivo and isolated myoblasts stimulated with insulin in vitro Gastrocnemius and soleus muscle weights were reduced by 25% in IUGR fetuses compared to those in controls (CON). The ratio of PAX7+ nuclei (a marker of myoblasts) to total nuclei was maintained in IUGR muscle compared to CON, but the fraction of PAX7+ myoblasts that also expressed Ki-67 (a marker of cellular proliferation) was reduced by 23%. Despite reduced proliferation in vivo, fetal myoblasts isolated from IUGR biceps femoris and cultured in enriched media in vitro responded robustly to insulin in a dose- and time-dependent manner to increase proliferation. Similarly, insulin stimulation of IUGR myoblasts upregulated key cell cycle genes and DNA replication. There were no differences in the expression of myogenic regulatory transcription factors that drive commitment to muscle differentiation between CON and IUGR groups. These results demonstrate that the molecular machinery necessary for transcriptional control of proliferation remains intact in IUGR fetal myoblasts, indicating that in vivo factors such as reduced insulin and IGF1, hypoxia and/or elevated counter-regulatory hormones may be inhibiting muscle growth in IUGR fetuses. © 2017 Society for Endocrinology.

  4. S100B Engages RAGE or bFGF/FGFR1 in Myoblasts Depending on Its Own Concentration and Myoblast Density. Implications for Muscle Regeneration

    Science.gov (United States)

    Beccafico, Sara; Donato, Rosario

    2012-01-01

    In high-density myoblast cultures S100B enhances basic fibroblast growth factor (bFGF) receptor 1 (FGFR1) signaling via binding to bFGF and blocks its canonical receptor, receptor for advanced glycation end-products (RAGE), thereby stimulating proliferation and inhibiting differentiation. Here we show that upon skeletal muscle injury S100B is released from myofibers with maximum release at day 1 post-injury in coincidence with satellite cell activation and the beginning of the myoblast proliferation phase, and declining release thereafter in coincidence with reduced myoblast proliferation and enhanced differentiation. By contrast, levels of released bFGF are remarkably low at day 1 post-injury, peak around day 5 and decline thereafter. We also show that in low-density myoblast cultures S100B binds RAGE, but not bFGF/FGFR1 thereby simultaneously stimulating proliferation via ERK1/2 and activating the myogenic program via p38 MAPK. Clearance of S100B after a 24-h treatment of low-density myoblasts results in enhanced myotube formation compared with controls as a result of increased cell numbers and activated myogenic program, whereas chronic treatment with S100B results in stimulation of proliferation and inhibition of differentiation due to a switch of the initial low-density culture to a high-density culture. However, at relatively high doses, S100B stimulates the mitogenic bFGF/FGFR1 signaling in low-density myoblasts, provided bFGF is present. We propose that S100B is a danger signal released from injured muscles that participates in skeletal muscle regeneration by activating the promyogenic RAGE or the mitogenic bFGF/FGFR1 depending on its own concentration, the absence or presence of bFGF, and myoblast density. PMID:22276098

  5. Transthyretin is a key regulator of myoblast differentiation.

    Directory of Open Access Journals (Sweden)

    Eun Ju Lee

    Full Text Available Transthyretin (TTR is a known carrier protein for thyroxine (T4 and retinol-binding protein in the blood that is primarily synthesized in the liver and choroid plexus of the brain. Herein, we report that the TTR gene is expressed in skeletal muscle tissue and up-regulated during myotube formation in C2C12 cells. TTR silencing (TTRkd significantly reduced myogenin expression and myotube formation, whereas myogenin silencing (MYOGkd did not have any effect on TTR gene expression. Both TTRkd and MYOGkd led to a decrease in calcium channel related genes including Cav1.1, STIM1 and Orai1. A significant decrease in intracellular T4 uptake during myogenesis was observed in TTRkd cells. Taken together, the results of this study suggest that TTR initiates myoblast differentiation via affecting expression of the genes involved during early stage of myogenesis and the genes related to calcium channel.

  6. Effects of myasthenia gravis patient sera on human myoblast cultures.

    Science.gov (United States)

    Luckman, S P; Skeie, G O; Helgeland, G; Gilhus, N E

    2006-01-01

    To investigate the role of acetylcholine receptor (AChR) and other anti-muscle autoantibodies in myasthenia gravis (MG). Since many of these autoantibodies target proteins with structural or signalling functions, we examined the effect of MG sera on muscle cell morphology. Primary human myoblast cultures were exposed to MG sera and morphological changes observed by light and fluorescence microscopy. MG patient sera caused changes in cell shape (cell retraction) and led to the formation of inclusion bodies and intracellular vesicles. A disordered arrangement of actin microfilaments was also observed. The effects were not complement-mediated, were both dose- and time-dependent, and appeared to correlate with disease severity of the MG donor. The factors responsible for these effects in vitro may also play a role in the pathogenesis of MG in vivo. Further study of these factors may improve our understanding of MG pathogenesis.

  7. Differentiation-Associated Downregulation of Poly(ADP-Ribose Polymerase-1 Expression in Myoblasts Serves to Increase Their Resistance to Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Gábor Oláh

    Full Text Available Poly(ADP-ribose polymerase 1 (PARP-1, the major isoform of the poly (ADP-ribose polymerase family, is a constitutive nuclear and mitochondrial protein with well-recognized roles in various essential cellular functions such as DNA repair, signal transduction, apoptosis, as well as in a variety of pathophysiological conditions including sepsis, diabetes and cancer. Activation of PARP-1 in response to oxidative stress catalyzes the covalent attachment of the poly (ADP-ribose (PAR groups on itself and other acceptor proteins, utilizing NAD+ as a substrate. Overactivation of PARP-1 depletes intracellular NAD+ influencing mitochondrial electron transport, cellular ATP generation and, if persistent, can result in necrotic cell death. Due to their high metabolic activity, skeletal muscle cells are particularly exposed to constant oxidative stress insults. In this study, we investigated the role of PARP-1 in a well-defined model of murine skeletal muscle differentiation (C2C12 and compare the responses to oxidative stress of undifferentiated myoblasts and differentiated myotubes. We observed a marked reduction of PARP-1 expression as myoblasts differentiated into myotubes. This alteration correlated with an increased resistance to oxidative stress of the myotubes, as measured by MTT and LDH assays. Mitochondrial function, assessed by measuring mitochondrial membrane potential, was preserved under oxidative stress in myotubes compared to myoblasts. Moreover, basal respiration, ATP synthesis, and the maximal respiratory capacity of mitochondria were higher in myotubes than in myoblasts. Inhibition of the catalytic activity of PARP-1 by PJ34 (a phenanthridinone PARP inhibitor exerted greater protective effects in undifferentiated myoblasts than in differentiated myotubes. The above observations in C2C12 cells were also confirmed in a rat-derived skeletal muscle cell line (L6. Forced overexpression of PARP1 in C2C12 myotubes sensitized the cells to oxidant

  8. Myostatin acts as an autocrine/paracrine negative regulator in myoblast differentiation from human induced pluripotent stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Fei; Kishida, Tsunao; Ejima, Akika [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan); Gojo, Satoshi [Department of Cardiac Support, Kyoto Prefectural University of Medicine, Kyoto (Japan); Mazda, Osam, E-mail: mazda@koto.kpu-m.ac.jp [Department of Immunology, Kyoto Prefectural University of Medicine, Kyoto (Japan)

    2013-02-08

    Highlights: ► iPS-derived cells express myostatin and its receptor upon myoblast differentiation. ► Myostatin inhibits myoblast differentiation by inhibiting MyoD and Myo5a induction. ► Silencing of myostatin promotes differentiation of human iPS cells into myoblasts. -- Abstract: Myostatin, also known as growth differentiation factor (GDF-8), regulates proliferation of muscle satellite cells, and suppresses differentiation of myoblasts into myotubes via down-regulation of key myogenic differentiation factors including MyoD. Recent advances in stem cell biology have enabled generation of myoblasts from pluripotent stem cells, but it remains to be clarified whether myostatin is also involved in regulation of artificial differentiation of myoblasts from pluripotent stem cells. Here we show that the human induced pluripotent stem (iPS) cell-derived cells that were induced to differentiate into myoblasts expressed myostatin and its receptor during the differentiation. An addition of recombinant human myostatin (rhMyostatin) suppressed induction of MyoD and Myo5a, resulting in significant suppression of myoblast differentiation. The rhMyostatin treatment also inhibited proliferation of the cells at a later phase of differentiation. RNAi-mediated silencing of myostatin promoted differentiation of human iPS-derived embryoid body (EB) cells into myoblasts. These results strongly suggest that myostatin plays an important role in regulation of myoblast differentiation from iPS cells of human origin. The present findings also have significant implications for potential regenerative medicine for muscular diseases.

  9. An HMGA2-IGF2BP2 axis regulates myoblast proliferation and myogenesis.

    Science.gov (United States)

    Li, Zhizhong; Gilbert, Jason A; Zhang, Yunyu; Zhang, Minsi; Qiu, Qiong; Ramanujan, Krishnan; Shavlakadze, Tea; Eash, John K; Scaramozza, Annarita; Goddeeris, Matthew M; Kirsch, David G; Campbell, Kevin P; Brack, Andrew S; Glass, David J

    2012-12-11

    A group of genes that are highly and specifically expressed in proliferating skeletal myoblasts during myogenesis was identified. Expression of one of these genes, Hmga2, increases coincident with satellite cell activation, and later its expression significantly declines correlating with fusion of myoblasts into myotubes. Hmga2 knockout mice exhibit impaired muscle development and reduced myoblast proliferation, while overexpression of HMGA2 promotes myoblast growth. This perturbation in proliferation can be explained by the finding that HMGA2 directly regulates the RNA-binding protein IGF2BP2. Add-back of IGF2BP2 rescues the phenotype. IGF2BP2 in turn binds to and controls the translation of a set of mRNAs, including c-myc, Sp1, and Igf1r. These data demonstrate that the HMGA2-IGF2BP2 axis functions as a key regulator of satellite cell activation and therefore skeletal muscle development. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Myoblast Fusion in Fly and Vertebrates: New Genes, New Processes and New Perspectives

    OpenAIRE

    Richardson, Brian E.; Nowak, Scott J.; Baylies, Mary K.

    2008-01-01

    Muscle formation and repair depends critically on the fusion of myoblasts. Despite the importance of this process, little is known about the cellular and molecular mechanisms regulating fusion. Forward genetic screens in Drosophila melanogaster have uncovered genes that, when mutated, prevent myoblast fusion. Analyses of these gene products have indicated that the actin cytoskeleton and its regulation play a central role in the fusion process. In this review, we discuss recent advances in the...

  11. Phosphorylation of Lbx1 controls lateral myoblast migration into the limb.

    Science.gov (United States)

    Masselink, Wouter; Masaki, Megumi; Sieiro, Daniel; Marcelle, Christophe; Currie, Peter D

    2017-10-15

    The migration of limb myogenic precursors from limb level somites to their ultimate site of differentiation in the limb is a paradigmatic example of a set of dynamic and orchestrated migratory cell behaviours. The homeobox containing transcription factor ladybird homeobox 1 (Lbx1) is a central regulator of limb myoblast migration, null mutations of Lbx1 result in severe disruptions to limb muscle formation, particularly in the distal region of the limb in mice (Gross et al., 2000). As such Lbx1 has been hypothesized to control lateral migration of myoblasts into the distal limb anlage. It acts as a core regulator of the limb myoblast migration machinery, controlled by Pax3. A secondary role for Lbx1 in the differentiation and commitment of limb musculature has also been proposed (Brohmann et al., 2000; Uchiyama et al., 2000). Here we show that lateral migration, but not differentiation or commitment of limb myoblasts, is controlled by the phosphorylation of three adjacent serine residues of LBX1. Electroporation of limb level somites in the chick embryo with a dephosphomimetic form of Lbx1 results in a specific defect in the lateral migration of limb myoblasts. Although the initial delamination and migration of myoblasts is unaffected, migration into the distal limb bud is severely disrupted. Interestingly, myoblasts undergo normal differentiation independent of their migratory status, suggesting that the differentiation potential of hypaxial muscle is not regulated by the phosphorylation state of LBX1. Furthermore, we show that FGF8 and ERK mediated signal transduction, both critical regulators of the developing limb bud, have the capacity to induce the phosphorylation of LBX1 at these residues. Overall, this suggests a mechanism whereby the phosphorylation of LBX1, potentially through FGF8 and ERK signalling, controls the lateral migration of myoblasts into the distal limb bud. Copyright © 2017. Published by Elsevier Inc.

  12. Elastic hydrogel substrate supports robust expansion of murine myoblasts and enhances their engraftment

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Ke, E-mail: dk1118@yeah.net [Department of Pediatric Surgery, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Chengdu 610072 (China); Yang, Zhong [Department of Clinical Hematology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Xu, Jian-zhong, E-mail: xjzspine@163.com [Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Liu, Wen-ying; Zeng, Qiang; Hou, Fang [Department of Pediatric Surgery, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, Chengdu 610072 (China); Lin, Sen [Department of Anatomy and Histology & Embryology, Chengdu Medical College, Chengdu 610500 (China)

    2015-09-10

    The application of satellite cell-derived myoblasts in regenerative medicine has been restricted by the rapid loss of stemness during in vitro cell expansion using traditional culture systems. However, studies published in the past decade have highlighted the influence of substrate elasticity on stem cell fate and revealed that culture on a soft hydrogel substrate can promote self-renewal and prolong the regenerative potential of muscle stem cells. Whether hydrogel substrates have similar effects after long-term robust expansion remains to be determined. Herein we prepared an elastic chitosan/beta-glycerophosphate/collagen hydrogel mimicking the soft microenvironment of muscle tissues for use as the substrate for satellite cell culture and investigated its influence on long-term cell expansion. After 20 passages in culture, satellite cell-derived myoblasts cultured on our hydrogel substrate exhibited significant improvements in proliferation capability, cell viability, colony forming frequency, and potential for myogenic differentiation compared to those cultured on a routine rigid culture surface. Immunochemical staining and western blot analysis both confirmed that myoblasts cultured on the hydrogel substrate expressed higher levels of several differentiation-related markers, including Pax7, Pax3, and SSEA-1, and a lower level of MyoD compared to myoblasts cultured on rigid culture plates (all p<0.05). After transplantation into the tibialis anterior of nude mice, myoblasts that had been cultured on the hydrogel substrate demonstrated a significantly greater engraftment efficacy than those cultured on the traditional surface. Collectively, these results indicate that the elastic hydrogel substrate supported robust expansion of murine myoblasts and enhanced their engraftment in vivo. - Highlights: • An elastic hydrogel was designed to mimic the pliable muscle tissue microenvironment. • Myoblasts retained their stemness in long-term culture on the elastic

  13. Balance between S-nitrosylation and denitrosylation modulates myoblast proliferation independently of soluble guanylyl cyclase activation.

    Science.gov (United States)

    Yamashita, Aline M S; Ancillotti, Maryana T C; Rangel, Luciana P; Fontenele, Marcio; Figueiredo-Freitas, Cicero; Possidonio, Ana C; Soares, Carolina P; Sorenson, Martha M; Mermelstein, Claudia; Nogueira, Leonardo

    2017-07-01

    Nitric oxide (NO) contributes to myogenesis by regulating the transition between myoblast proliferation and fusion through cGMP signaling. NO can form S-nitrosothiols (RSNO), which control signaling pathways in many different cell types. However, neither the role of RSNO content nor its regulation by the denitrosylase activity of S-nitrosoglutathione reductase (GSNOR) during myogenesis is understood. Here, we used primary cultures of chick embryonic skeletal muscle cells to investigate whether changes in intracellular RSNO alter proliferation and fusion of myoblasts in the presence and absence of cGMP. Cultures were grown to fuse most of the myoblasts into myotubes, with and without S-nitrosocysteine (CysNO), 8-Br-cGMP, DETA-NO, or inhibitors for NO synthase (NOS), GSNOR, soluble guanylyl cyclase (sGC), or a combination of these, followed by analysis of GSNOR activity, protein expression, RSNO, cGMP, and cell morphology. Although the activity of GSNOR increased progressively over 72 h, inhibiting GSNOR (by GSNOR inhibitor - GSNORi - or by knocking down GSNOR with siRNA) produced an increase in RSNO and in the number of myoblasts and fibroblasts, accompanied by a decrease in myoblast fusion index. This was also detected with CysNO supplementation. Enhanced myoblast number was proportional to GSNOR inhibition. Effects of the GSNORi and GSNOR knockdown were blunted by NOS inhibition, suggesting their dependence on NO synthesis. Interestingly, GSNORi and GSNOR knockdown reversed the attenuated proliferation obtained with sGC inhibition in myoblasts, but not in fibroblasts. Hence myoblast proliferation is enhanced by increasing RSNO, and regulated by GSNOR activity, independently of cGMP production and signaling. Copyright © 2017 the American Physiological Society.

  14. Phospholipase D1 facilitates second-phase myoblast fusion and skeletal muscle regeneration.

    Science.gov (United States)

    Teng, Shuzhi; Stegner, David; Chen, Qin; Hongu, Tsunaki; Hasegawa, Hiroshi; Chen, Li; Kanaho, Yasunori; Nieswandt, Bernhard; Frohman, Michael A; Huang, Ping

    2015-02-01

    Myoblast differentiation and fusion is a well-orchestrated multistep process that is essential for skeletal muscle development and regeneration. Phospholipase D1 (PLD1) has been implicated in the initiation of myoblast differentiation in vitro. However, whether PLD1 plays additional roles in myoblast fusion and exerts a function in myogenesis in vivo remains unknown. Here we show that PLD1 expression is up-regulated in myogenic cells during muscle regeneration after cardiotoxin injury and that genetic ablation of PLD1 results in delayed myofiber regeneration. Myoblasts derived from PLD1-null mice or treated with PLD1-specific inhibitor are unable to form mature myotubes, indicating defects in second-phase myoblast fusion. Concomitantly, the PLD1 product phosphatidic acid is transiently detected on the plasma membrane of differentiating myocytes, and its production is inhibited by PLD1 knockdown. Exogenous lysophosphatidylcholine, a key membrane lipid for fusion pore formation, partially rescues fusion defect resulting from PLD1 inhibition. Thus these studies demonstrate a role for PLD1 in myoblast fusion during myogenesis in which PLD1 facilitates the fusion of mononuclear myocytes with nascent myotubes. © 2015 Teng et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  15. FSHD myoblasts fail to downregulate intermediate filament protein vimentin during myogenic differentiation.

    Directory of Open Access Journals (Sweden)

    Lipinski M.

    2011-10-01

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is an autosomal dominant hereditary neuromuscular disorder. The clinical features of FSHD include weakness of the facial and shoulder girdle muscles followed by wasting of skeletal muscles of the pelvic girdle and lower extremities. Although FSHD myoblasts grown in vitro can be induced to differentiate into myotubes by serum starvation, the resulting FSHD myotubes have been shown previously to be morphologically abnormal. Aim. In order to find the cause of morphological anomalies of FSHD myotubes we compared in vitro myogenic differentiation of normal and FSHD myoblasts at the protein level. Methods. We induced myogenic differentiation of normal and FSHD myoblasts by serum starvation. We then compared protein extracts from proliferating myoblasts and differentiated myotubes using SDS-PAGE followed by mass spectrometry identification of differentially expressed proteins. Results. We demonstrated that the expression of vimentin was elevated at the protein and mRNA levels in FSHD myotubes as compared to normal myotubes. Conclusions. We demonstrate for the first time that in contrast to normal myoblasts, FSHD myoblasts fail to downregulate vimentin after induction of in vitro myogenic differentiation. We suggest that vimentin could be an easily detectable marker of FSHD myotubes

  16. The small G-proteins Rac1 and Cdc42 are essential for myoblast fusion in the mouse

    DEFF Research Database (Denmark)

    Vasyutina, Elena; Martarelli, Benedetta; Brakebusch, Cord

    2009-01-01

    Rac1 and Cdc42 are small G-proteins that regulate actin dynamics and affect plasma membrane protrusion and vesicle traffic. We used conditional mutagenesis in mice to demonstrate that Rac1 and Cdc42 are essential for myoblast fusion in vivo and in vitro. The deficit in fusion of Rac1 or Cdc42...... mutant myoblasts correlates with a deficit in the recruitment of actin fibers and vinculin to myoblast contact sites. Comparison of the changes observed in mutant myogenic cells indicates that Rac1 and Cdc42 function in a nonredundant and not completely overlapping manner during the fusion process. Our...... genetic analysis demonstrates thus that the function of Rac in myoblast fusion is evolutionarily conserved from insects to mammals and that Cdc42, a molecule hitherto not implicated in myoblast fusion, is essential for the fusion of murine myoblasts....

  17. Automated high-content assay for compounds selectively toxic to Trypanosoma cruzi in a myoblastic cell line.

    Directory of Open Access Journals (Sweden)

    Julio Alonso-Padilla

    2015-01-01

    Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, represents a very important public health problem in Latin America where it is endemic. Although mostly asymptomatic at its initial stage, after the disease becomes chronic, about a third of the infected patients progress to a potentially fatal outcome due to severe damage of heart and gut tissues. There is an urgent need for new drugs against Chagas disease since there are only two drugs available, benznidazole and nifurtimox, and both show toxic side effects and variable efficacy against the chronic stage of the disease.Genetically engineered parasitic strains are used for high throughput screening (HTS of large chemical collections in the search for new anti-parasitic compounds. These assays, although successful, are limited to reporter transgenic parasites and do not cover the wide T. cruzi genetic background. With the aim to contribute to the early drug discovery process against Chagas disease we have developed an automated image-based 384-well plate HTS assay for T. cruzi amastigote replication in a rat myoblast host cell line. An image analysis script was designed to inform on three outputs: total number of host cells, ratio of T. cruzi amastigotes per cell and percentage of infected cells, which respectively provides one host cell toxicity and two T. cruzi toxicity readouts. The assay was statistically robust (Z´ values >0.6 and was validated against a series of known anti-trypanosomatid drugs.We have established a highly reproducible, high content HTS assay for screening of chemical compounds against T. cruzi infection of myoblasts that is amenable for use with any T. cruzi strain capable of in vitro infection. Our visual assay informs on both anti-parasitic and host cell toxicity readouts in a single experiment, allowing the direct identification of compounds selectively targeted to the parasite.

  18. The Mouse C2C12 Myoblast Cell Surface N-Linked Glycoproteome

    Science.gov (United States)

    Gundry, Rebekah L.; Raginski, Kimberly; Tarasova, Yelena; Tchernyshyov, Irina; Bausch-Fluck, Damaris; Elliott, Steven T.; Boheler, Kenneth R.; Van Eyk, Jennifer E.; Wollscheid, Bernd

    2009-01-01

    Endogenous regeneration and repair mechanisms are responsible for replacing dead and damaged cells to maintain or enhance tissue and organ function, and one of the best examples of endogenous repair mechanisms involves skeletal muscle. Although the molecular mechanisms that regulate the differentiation of satellite cells and myoblasts toward myofibers are not fully understood, cell surface proteins that sense and respond to their environment play an important role. The cell surface capturing technology was used here to uncover the cell surface N-linked glycoprotein subproteome of myoblasts and to identify potential markers of myoblast differentiation. 128 bona fide cell surface-exposed N-linked glycoproteins, including 117 transmembrane, four glycosylphosphatidylinositol-anchored, five extracellular matrix, and two membrane-associated proteins were identified from mouse C2C12 myoblasts. The data set revealed 36 cluster of differentiation-annotated proteins and confirmed the occupancy for 235 N-linked glycosylation sites. The identification of the N-glycosylation sites on the extracellular domain of the proteins allowed for the determination of the orientation of the identified proteins within the plasma membrane. One glycoprotein transmembrane orientation was found to be inconsistent with Swiss-Prot annotations, whereas ambiguous annotations for 14 other proteins were resolved. Several of the identified N-linked glycoproteins, including aquaporin-1 and β-sarcoglycan, were found in validation experiments to change in overall abundance as the myoblasts differentiate toward myotubes. Therefore, the strategy and data presented shed new light on the complexity of the myoblast cell surface subproteome and reveal new targets for the clinically important characterization of cell intermediates during myoblast differentiation into myotubes. PMID:19656770

  19. Thermal manipulation during embryogenesis affects myoblast proliferation and skeletal muscle growth in meat-type chickens.

    Science.gov (United States)

    Piestun, Yogev; Yahav, Shlomo; Halevy, Orna

    2015-10-01

    Thermal manipulation (TM) of 39.5°C applied during mid-embryogenesis (embryonic d 7 to 16) has been proven to promote muscle development and enhance muscle growth and meat production in meat-type chickens. This study aimed to elucidate the cellular basis for this effect. Continuous TM or intermittent TM (for 12 h/d) increased myoblast proliferation manifested by higher (25 to 48%) myoblast number in the pectoral muscles during embryonic development but also during the first week posthatch. Proliferation ability of the pectoral-muscle-derived myoblasts in vitro was significantly higher in the TM treatments until embryonic d 15 (intermittent TM) or 13 (continuous TM) compared to that of controls, suggesting increased myogenic progeny reservoir in the muscle. However, the proliferation ability of myoblasts was lower in the TM treatments vs. control during the last days of incubation. This coincided with higher levels of myogenin expression in the muscle, indicating enhanced cell differentiation in the TM muscle. A similar pattern was observed posthatch: Myoblast proliferation was significantly higher in the TM chicks relative to controls during the peak of posthatch cell proliferation until d 6, followed by lower cell number 2 wk posthatch as myoblast number sharply decreases. Higher myogenin expression was observed in the TM chicks on d 6. This resulted in increased muscle growth, manifested by significantly higher relative weight of breast muscle in the embryo and posthatch. It can be concluded that temperature elevation during mid-term embryogenesis promotes myoblast proliferation, thus increasing myogenic progeny reservoir in the muscle, resulting in enhanced muscle growth in the embryo and posthatch. © 2015 Poultry Science Association Inc.

  20. Culture Conditions Affect Expression of DUX4 in FSHD Myoblasts

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    Sachchida Nand Pandey

    2015-05-01

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is believed to be caused by aberrant expression of double homeobox 4 (DUX4 due to epigenetic changes of the D4Z4 region at chromosome 4q35. Detecting DUX4 is challenging due to its stochastic expression pattern and low transcription level. In this study, we examined different cDNA synthesis strategies and the sensitivity for DUX4 detection. In addition, we investigated the effects of dexamethasone and knockout serum replacement (KOSR on DUX4 expression in culture. Our data showed that DUX4 was consistently detected in cDNA samples synthesized using Superscript III. The sensitivity of DUX4 detection was higher in the samples synthesized using oligo(dT primers compared to random hexamers. Adding dexamethasone to the culture media significantly suppressed DUX4 expression in immortalized (1.3 fold, p < 0.01 and primary (4.7 fold, p < 0.01 FSHD myoblasts, respectively. Culture medium with KOSR increased DUX4 expression and the response is concentration dependent. The findings suggest that detection strategies and culture conditions should be carefully considered when studying DUX4 in cultured cells.

  1. Prosome cytodistribution relative to desmin and actin filaments in dividing C2.7 myoblasts and during myotube formation in vitro.

    Science.gov (United States)

    De Conto, F; Missorini, S; Arcangeletti, C; Pinardi, F; Montarras, D; Pinset, C; Vassy, J; Géraud, G; Chezzi, C; Scherrer, K

    1997-05-25

    Prosomes constitute the multicatalytic proteinase (MCP) core of the 26S proteasomes, but were first observed as subcomplexes of untranslated mRNP; this suggests that they play a putative role in the control of protein biosynthesis in addition to their catabolic enzymatic function. In previous investigations it was shown that some prosomes colocalize with the intermediate filaments (IF) of the cytoskeleton, of the cytokeratin type in epithelial cells, and of the vimentin type in fibroblasts. Studies on adult rat muscle carried out with prosome-specific monoclonal antibodies (p-mAbs) have shown, surprisingly, that specific types of prosomes predominantly occupy a particular zone in between the M and the Z lines of the sarcomeric structure. The data presented here show that the subunit composition of prosomes changes when the dividing C2.7 myoblasts fuse into myotubes. We show furthermore that, in dividing C2.7 myoblasts, prosomes colocalize with the desmin network as well as with that of actin, in a distribution that changes with the subunit pattern of the prosomes investigated by individual p-mAbs. Surprisingly, when myogenic fusion is induced, specific types of prosomes move first to the nuclei; later on, they reappear in the cytoplasm. There, superimposing initially onto the reorganizing desmin filaments that run from one pole of the prefusion myoblast to the other, prosomes gradually colocalize with the actin fibers in the fusing myotubes, finally forming a "pearl on a string" pattern. These results are discussed in relation to parallel observations of prosome distribution between the actin and IF networks not only in epithelial cells but also in fusing muscle satellite cells, which made it possible to monitor the complete buildup of the sarcomeric structure.

  2. The MARVEL domain protein, Singles Bar, is required for progression past the pre-fusion complex stage of myoblast fusion.

    Science.gov (United States)

    Estrada, Beatriz; Maeland, Anne D; Gisselbrecht, Stephen S; Bloor, James W; Brown, Nicholas H; Michelson, Alan M

    2007-07-15

    Multinucleated myotubes develop by the sequential fusion of individual myoblasts. Using a convergence of genomic and classical genetic approaches, we have discovered a novel gene, singles bar (sing), that is essential for myoblast fusion. sing encodes a small multipass transmembrane protein containing a MARVEL domain, which is found in vertebrate proteins involved in processes such as tight junction formation and vesicle trafficking where--as in myoblast fusion--membrane apposition occurs. sing is expressed in both founder cells and fusion competent myoblasts preceding and during myoblast fusion. Examination of embryos injected with double-stranded sing RNA or embryos homozygous for ethane methyl sulfonate-induced sing alleles revealed an identical phenotype: replacement of multinucleated myofibers by groups of single, myosin-expressing myoblasts at a stage when formation of the mature muscle pattern is complete in wild-type embryos. Unfused sing mutant myoblasts form clusters, suggesting that early recognition and adhesion of these cells are unimpaired. To further investigate this phenotype, we undertook electron microscopic ultrastructural studies of fusing myoblasts in both sing and wild-type embryos. These experiments revealed that more sing mutant myoblasts than wild-type contain pre-fusion complexes, which are characterized by electron-dense vesicles paired on either side of the fusing plasma membranes. In contrast, embryos mutant for another muscle fusion gene, blown fuse (blow), have a normal number of such complexes. Together, these results lead to the hypothesis that sing acts at a step distinct from that of blow, and that sing is required on both founder cell and fusion-competent myoblast membranes to allow progression past the pre-fusion complex stage of myoblast fusion, possibly by mediating fusion of the electron-dense vesicles to the plasma membrane.

  3. Isolation, Culturing, and Differentiation of Primary Myoblasts from Skeletal Muscle of Adult Mice.

    Science.gov (United States)

    Hindi, Lubna; McMillan, Joseph D; Afroze, Dil; Hindi, Sajedah M; Kumar, Ashok

    2017-05-05

    Myogenesis is a multi-step process that leads to the formation of skeletal muscle during embryonic development and repair of injured myofibers. In this process, myoblasts are the main effector cell type which fuse with each other or to injured myofibers leading to the formation of new myofibers or regeneration of skeletal muscle in adults. Many steps of myogenesis can be recapitulated through in vitro differentiation of myoblasts into myotubes. Most laboratories use immortalized myogenic cells lines that also differentiate into myotubes. Although these cell lines have been found quite useful to delineating the regulatory mechanisms of myogenesis, they often show a great degree of variability depending on the origin of the cells and culture conditions. Primary myoblasts have been suggested as the most physiologically relevant model for studying myogenesis in vitro. However, due to their low abundance in adult skeletal muscle, isolation of primary myoblasts is technically challenging. In this article, we describe an improved protocol for the isolation of primary myoblasts from adult skeletal muscle of mice. We also describe methods for their culturing and differentiation into myotubes.

  4. Live cell imaging reveals marked variability in myoblast proliferation and fate

    Science.gov (United States)

    2013-01-01

    Background During the process of muscle regeneration, activated stem cells termed satellite cells proliferate, and then differentiate to form new myofibers that restore the injured area. Yet not all satellite cells contribute to muscle repair. Some continue to proliferate, others die, and others become quiescent and are available for regeneration following subsequent injury. The mechanisms that regulate the adoption of different cell fates in a muscle cell precursor population remain unclear. Methods We have used live cell imaging and lineage tracing to study cell fate in the C2 myoblast line. Results Analyzing the behavior of individual myoblasts revealed marked variability in both cell cycle duration and viability, but similarities between cells derived from the same parental lineage. As a consequence, lineage sizes and outcomes differed dramatically, and individual lineages made uneven contributions toward the terminally differentiated population. Thus, the cohort of myoblasts undergoing differentiation at the end of an experiment differed dramatically from the lineages present at the beginning. Treatment with IGF-I increased myoblast number by maintaining viability and by stimulating a fraction of cells to complete one additional cell cycle in differentiation medium, and as a consequence reduced the variability of the terminal population compared with controls. Conclusion Our results reveal that heterogeneity of responses to external cues is an intrinsic property of cultured myoblasts that may be explained in part by parental lineage, and demonstrate the power of live cell imaging for understanding how muscle differentiation is regulated. PMID:23638706

  5. NANOG restores the impaired myogenic differentiation potential of skeletal myoblasts after multiple population doublings

    Directory of Open Access Journals (Sweden)

    Aref Shahini

    2018-01-01

    Full Text Available Adult skeletal muscle regeneration relies on the activity of satellite cells residing in the skeletal muscle niche. However, systemic and intrinsic factors decrease the myogenic differentiation potential of satellite cells thereby impairing muscle regeneration. Here we present data showing that late passage C2C12 myoblasts exhibited significantly impaired myogenic differentiation potential that was accompanied by impaired expression of myogenic regulatory factors (Myf5, MyoD, Myogenin, and MRF4 and members of myocyte enhancer factor 2 family. Notably, ectopic expression of NANOG preserved the morphology and restored the myogenic differentiation capacity of late passage myoblasts, possibly by restoring the expression level of these myogenic factors. Muscle regeneration was effective in 2D cultures and in 3D skeletal microtissues mimicking the skeletal muscle niche. The presence of NANOG was required for at least 15 days to reverse the impaired differentiation potential of myoblasts. However, it was critical to remove NANOG during the process of maturation, as it inhibited myotube formation. Finally, myoblasts that were primed by NANOG maintained their differentiation capacity for 20 days after NANOG withdrawal, suggesting potential epigenetic changes. In conclusion, these results shed light on the potential of NANOG to restore the myogenic differentiation potential of myoblasts, which is impaired after multiple rounds of cellular division, and to reverse the loss of muscle regeneration.

  6. Loss of MyoD Promotes Fate Transdifferentiation of Myoblasts Into Brown Adipocytes

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    Chao Wang

    2017-02-01

    Full Text Available Brown adipose tissue (BAT represents a promising agent to ameliorate obesity and other metabolic disorders. However, the abundance of BAT decreases with age and BAT paucity is a common feature of obese subjects. As brown adipocytes and myoblasts share a common Myf5 lineage origin, elucidating the molecular mechanisms underlying the fate choices of brown adipocytes versus myoblasts may lead to novel approaches to expand BAT mass. Here we identify MyoD as a key negative regulator of brown adipocyte development. CRISPR/CAS9-mediated deletion of MyoD in C2C12 myoblasts facilitates their adipogenic transdifferentiation. MyoD knockout downregulates miR-133 and upregulates the miR-133 target Igf1r, leading to amplification of PI3K–Akt signaling. Accordingly, inhibition of PI3K or Akt abolishes the adipogenic gene expression of MyoD null myoblasts. Strikingly, loss of MyoD converts satellite cell-derived primary myoblasts to brown adipocytes through upregulation of Prdm16, a target of miR-133 and key determinant of brown adipocyte fate. Conversely, forced expression of MyoD in brown preadipocytes blocks brown adipogenesis and upregulates the expression of myogenic genes. Importantly, miR-133a knockout significantly blunts the inhibitory effect of MyoD on brown adipogenesis. Our results establish MyoD as a negative regulator of brown adipocyte development by upregulating miR-133 to suppress Akt signaling and Prdm16.

  7. MyD88 promotes myoblast fusion in a cell-autonomous manner.

    Science.gov (United States)

    Hindi, Sajedah M; Shin, Jonghyun; Gallot, Yann S; Straughn, Alex R; Simionescu-Bankston, Adriana; Hindi, Lubna; Xiong, Guangyan; Friedland, Robert P; Kumar, Ashok

    2017-11-20

    Myoblast fusion is an indispensable step for skeletal muscle development, postnatal growth, and regeneration. Myeloid differentiation primary response gene 88 (MyD88) is an adaptor protein that mediates Toll-like receptors and interleukin-1 receptor signaling. Here we report a cell-autonomous role of MyD88 in the regulation of myoblast fusion. MyD88 protein levels are increased during in vitro myogenesis and in conditions that promote skeletal muscle growth in vivo. Deletion of MyD88 impairs fusion of myoblasts without affecting their survival, proliferation, or differentiation. MyD88 regulates non-canonical NF-κB and canonical Wnt signaling during myogenesis and promotes skeletal muscle growth and overload-induced myofiber hypertrophy in mice. Ablation of MyD88 reduces myofiber size during muscle regeneration, whereas its overexpression promotes fusion of exogenous myoblasts to injured myofibers. Our study shows that MyD88 modulates myoblast fusion and suggests that augmenting its levels may be a therapeutic approach to improve skeletal muscle formation in degenerative muscle disorders.

  8. AP-2{alpha} suppresses skeletal myoblast proliferation and represses fibroblast growth factor receptor 1 promoter activity

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Darrion L. [Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 (United States); DiMario, Joseph X., E-mail: joseph.dimario@rosalindfranklin.edu [Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 (United States)

    2010-01-15

    Skeletal muscle development is partly characterized by myoblast proliferation and subsequent differentiation into postmitotic muscle fibers. Developmental regulation of expression of the fibroblast growth factor receptor 1 (FGFR1) gene is required for normal myoblast proliferation and muscle formation. As a result, FGFR1 promoter activity is controlled by multiple transcriptional regulatory proteins during both proliferation and differentiation of myogenic cells. The transcription factor AP-2{alpha} is present in nuclei of skeletal muscle cells and suppresses myoblast proliferation in vitro. Since FGFR1 gene expression is tightly linked to myoblast proliferation versus differentiation, the FGFR1 promoter was examined for candidate AP-2{alpha} binding sites. Mutagenesis studies indicated that a candidate binding site located at - 1035 bp functioned as a repressor cis-regulatory element. Furthermore, mutation of this site alleviated AP-2{alpha}-mediated repression of FGFR1 promoter activity. Chromatin immunoprecipitation studies demonstrated that AP-2{alpha} interacted with the FGFR1 promoter in both proliferating myoblasts and differentiated myotubes. In total, these results indicate that AP-2{alpha} is a transcriptional repressor of FGFR1 gene expression during skeletal myogenesis.

  9. The real estate of myoblast cardiac transplantation: negative remodeling is associated with location.

    Science.gov (United States)

    McCue, Jonathan D; Swingen, Cory; Feldberg, Tanya; Caron, Gabe; Kolb, Adam; Denucci, Christopher; Prabhu, Somnath; Motilall, Randy; Breviu, Brian; Taylor, Doris A

    2008-01-01

    Skeletal myoblast transplantation has been proposed as a therapy for ischemic cardiomyopathy owing to its possible role in myogenesis. The relative safety and efficacy based on location within scar is not known. We hypothesized that skeletal myoblasts transplanted into peripheral scar (compared with central scar) would more effectively attenuate negative left ventricular (LV) remodeling but at the risk of arrhythmia. New Zealand White rabbits (n = 34) underwent mid-left anterior descending artery (LAD) ligation to produce a transmural LV infarction. One month after LAD ligation, skeletal myoblasts were injected either in the scar center (n = 13) or scar periphery (n = 10) and compared with saline injection (n = 11). Holter monitoring and magnetic resonance imaging (MRI) was performed pre-injection; Holter monitoring was continued until 2 weeks after injection, with follow-up MRI at 1 month. The centrally treated animals demonstrated increased LV end-systolic volume, end-diastolic volume, and mass that correlated with the number of injected cells. There was a trend toward attenuation of negative LV remodeling in peripherally treated animals compared with vehicle. Significant late ectopy was seen in several centrally injected animals, with no late ectopy seen in peripherally injected animals. We noted untoward effects with respect to negative LV remodeling after central injection, suggesting that transplanted cell location with respect to scar may be a key factor in the safety and efficacy of skeletal myoblast cardiac transplantation. Administration of skeletal myoblasts into peripheral scar appears safe, with a trend toward improved function in comparison with sham injection.

  10. CRYOPRESERVATION EFFECTS ON RECOMBINANT MYOBLASTS ENCAPSULATED IN ADHESIVE ALGINATE HYDROGELS

    Science.gov (United States)

    Ahmad, Hajira F.; Sambanis, Athanassios

    2013-01-01

    Cell encapsulation in hydrogels is widely used in tissue engineering applications, including encapsulation of islets or other insulin-secreting cells in pancreatic substitutes. Use of adhesive, bio-functionalized hydrogels is receiving increasing attention, as cell-matrix interactions in 3-D can be important for various cell processes. With pancreatic substitutes, studies have indicated benefits of 3-D adhesion on the viability and/or function of insulin-secreting cells. As long-term storage of microencapsulated cells is critical for their clinical translation, cryopreservation of cells in hydrogels is actively being investigated. Previous studies have examined the cryopreservation response of cells encapsulated in non-adhesive hydrogels using conventional freezing and/or vitrification (ice-free cryopreservation), however, none have systematically compared the two cryopreservation methods with cells encapsulated within an adhesive 3-D environment. The latter would be significant, as evidence suggests adhesion influences cellular response to cryopreservation. Thus, the objective of this study was to determine the response to conventional freezing and vitrification of insulin-secreting cells encapsulated in an adhesive biomimetic hydrogel. Recombinant insulin-secreting C2C12 myoblasts were encapsulated in oxidized RGD-alginate and cultured 1 or 4 days post-encapsulation, cryopreserved, and assessed up to 3 days post-warming for metabolic activity and insulin secretion, and one day post-warming for cell morphology. Besides certain transient differences of the vitrified group relative to the Fresh control, both conventional freezing and vitrification maintained metabolism, secretion and morphology of the recombinant C2C12 cells. Thus, due to a simpler procedure and slightly superior results, conventional freezing is recommended over vitrification for the cryopreservation of C2C12 cells in oxidized RGD-modified alginate. PMID:23499987

  11. Myoblasts from intrauterine growth-restricted sheep fetuses exhibit intrinsic deficiencies in proliferation that contribute to smaller semitendinosus myofibres

    Science.gov (United States)

    Yates, Dustin T; Clarke, Derek S; Macko, Antoni R; Anderson, Miranda J; Shelton, Leslie A; Nearing, Marie; Allen, Ronald E; Rhoads, Robert P; Limesand, Sean W

    2014-01-01

    Intrauterine growth restriction (IUGR) reduces skeletal muscle mass in fetuses and offspring. Our objective was to determine whether myoblast dysfunction due to intrinsic cellular deficiencies or serum factors reduces myofibre hypertrophy in IUGR fetal sheep. At 134 days, IUGR fetuses weighed 67% less (P IUGR semitendinosus muscles had similar percentages of pax7-positive nuclei and pax7 mRNA but lower (P IUGR fetuses had 34% fewer (P IUGR myoblasts also replicated less (P IUGR fetal sheep serum (FSS). Both myoblast types replicated less (P IUGR FSS-supplemented media compared to control FSS-supplemented media. In differentiation-promoting media (2% FBS), IUGR and control myoblasts had similar percentages of myogenin-positive nuclei after 5 days and formed similar-sized myotubes after 7 days. We conclude that intrinsic cellular deficiencies in IUGR myoblasts and factors in IUGR serum diminish myoblast proliferation and myofibre size in IUGR fetuses, but intrinsic myoblast deficiencies do not affect differentiation. Furthermore, the persistent reduction in IUGR myoblast replication shows adaptive deficiencies that explain poor muscle growth in IUGR newborn offspring. PMID:24860171

  12. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) activates promyogenic signaling pathways, thereby promoting myoblast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Jin; Go, Ga-Yeon; Yoo, Miran; Kim, Yong Kee [Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Seo, Dong-Wan [College of Pharmacy, Dankook University, Cheonan 330-714 (Korea, Republic of); Kang, Jong-Sun [Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Suwon 440-746 (Korea, Republic of); Bae, Gyu-Un, E-mail: gbae@sookmyung.ac.kr [Research Center for Cell Fate Control, College of Pharmacy, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of)

    2016-01-29

    Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) regulates postnatal myogenesis by alleviating myostatin activity, but the molecular mechanisms by which it regulates myogenesis are not fully understood. In this study, we investigate molecular mechanisms of PPARβ/δ in myoblast differentiation. C2C12 myoblasts treated with a PPARβ/δ agonist, GW0742 exhibit enhanced myotube formation and muscle-specific gene expression. GW0742 treatment dramatically activates promyogenic kinases, p38MAPK and Akt, in a dose-dependent manner. GW0742-stimulated myoblast differentiation is mediated by p38MAPK and Akt, since it failed to restore myoblast differentiation repressed by inhibition of p38MAPK and Akt. In addition, GW0742 treatment enhances MyoD-reporter activities. Consistently, overexpression of PPARβ/δ enhances myoblast differentiation accompanied by elevated activation of p38MAPK and Akt. Collectively, these results suggest that PPARβ/δ enhances myoblast differentiation through activation of promyogenic signaling pathways. - Highlights: • A PPARβ/δ agonist, GW0742 promotes myoblast differentiation. • GW0742 activates both p38MAPK and Akt activation in myogenic differentiation. • GW0742 enhances MyoD activity for myogenic differentiation. • Overexpression of PPARβ/δ enhances myoblast differentiation via activating promyogenic signaling pathways. • This is the first finding for agonistic mechanism of PPARβ/δ in myogenesis.

  13. Injectable scaffold materials differ in their cell instructive effects on primary human myoblasts

    DEFF Research Database (Denmark)

    Hejbøl, Eva Kildall; Sellathurai, Jeeva; Nair, Prabha Damodaran

    2017-01-01

    a minimally invasive technique. In this study, we examined in vitro the cell instructive effects of three types of injectable scaffolds, fibrin, alginate, and poly(lactic-co-glycolic acid)-based microparticles on primary human myoblasts. The myoblast morphology and progression in the myogenic program differed......, depending on the type of scaffold material. In alginate gel, the cells obtained a round morphology, they ceased to proliferate, and entered quiescence. In the fibrin gels, differentiation was promoted, and myotubes were observed within a few days in culture, while poly(lactic-co-glycolic acid......)-based microparticles supported prolonged proliferation. Myoblasts released from the alginate and fibrin gels were studied, and cells released from these scaffolds had retained the ability to proliferate and differentiate. Thus, the study shows that human myogenic cells combined with injectable scaffold materials...

  14. The physical interaction of myoblasts with the microenvironment during remodeling of the cytoarchitecture.

    Directory of Open Access Journals (Sweden)

    Daniel J Modulevsky

    Full Text Available Integrins, focal adhesions, the cytoskeleton and the extracellular matrix, form a structural continuum between the external and internal environment of the cell and mediate the pathways associated with cellular mechanosensitivity and mechanotransduction. This continuum is important for the onset of muscle tissue generation, as muscle precursor cells (myoblasts require a mechanical stimulus to initiate myogenesis. The ability to sense a mechanical cue requires an intact cytoskeleton and strong physical contact and adhesion to the microenvironment. Importantly, myoblasts also undergo reorientation, alignment and large scale remodeling of the cytoskeleton when they experience mechanical stretch and compression in muscle tissue. It remains unclear if such dramatic changes in cell architecture also inhibit physical contact and adhesion with the tissue microenvironment that are clearly important to myoblast physiology. In this study, we employed interference reflection microscopy to examine changes in the close physical contact of myoblasts with a substrate during induced remodeling of the cytoarchitecture (de-stabilization of the actin and microtubule cytoskeleton and inhibition of acto-myosin contractility. Our results demonstrate that while each remodeling pathway caused distinct effects on myoblast morphology and sub-cellular structure, we only observed a ~13% decrease in close physical contact with the substrate, regardless of the pathway inhibited. However, this decrease did not correlate well with changes in cell adhesion strength. On the other hand, there was a close correlation between cell adhesion and β1-integrin expression and the presence of cell-secreted fibronectin, but not with the presence of intact focal adhesions. In this study, we have shown that myoblasts are able to maintain a large degree of physical contact and adhesion to the microenvironment, even during shot periods (<60 min of large scale remodeling and physiological

  15. Bone marrow mesenchymal stromal cells stimulate skeletal myoblast proliferation through the paracrine release of VEGF.

    Directory of Open Access Journals (Sweden)

    Chiara Sassoli

    Full Text Available Mesenchymal stromal cells (MSCs are the leading cell candidates in the field of regenerative medicine. These cells have also been successfully used to improve skeletal muscle repair/regeneration; however, the mechanisms responsible for their beneficial effects remain to be clarified. On this basis, in the present study, we evaluated in a co-culture system, the ability of bone-marrow MSCs to influence C2C12 myoblast behavior and analyzed the cross-talk between the two cell types at the cellular and molecular level. We found that myoblast proliferation was greatly enhanced in the co-culture as judged by time lapse videomicroscopy, cyclin A expression and EdU incorporation. Moreover, myoblasts immunomagnetically separated from MSCs after co-culture expressed higher mRNA and protein levels of Notch-1, a key determinant of myoblast activation and proliferation, as compared with the single culture. Notch-1 intracellular domain and nuclear localization of Hes-1, a Notch-1 target gene, were also increased in the co-culture. Interestingly, the myoblastic response was mainly dependent on the paracrine release of vascular endothelial growth factor (VEGF by MSCs. Indeed, the addition of MSC-derived conditioned medium (CM to C2C12 cells yielded similar results as those observed in the co-culture and increased the phosphorylation and expression levels of VEGFR. The treatment with the selective pharmacological VEGFR inhibitor, KRN633, resulted in a marked attenuation of the receptor activation and concomitantly inhibited the effects of MSC-CM on C2C12 cell growth and Notch-1 signaling. In conclusion, this study provides novel evidence for a role of MSCs in stimulating myoblast cell proliferation and suggests that the functional interaction between the two cell types may be exploited for the development of new and more efficient cell-based skeletal muscle repair strategies.

  16. TAK-1/p38/nNFκB signaling inhibits myoblast differentiation by increasing levels of Activin A

    Directory of Open Access Journals (Sweden)

    Trendelenburg Anne

    2012-02-01

    Full Text Available Abstract Background Skeletal-muscle differentiation is required for the regeneration of myofibers after injury. The differentiation capacity of satellite cells is impaired in settings of old age, which is at least one factor in the onset of sarcopenia, the age-related loss of skeletal-muscle mass and major cause of frailty. One important cause of impaired regeneration is increased levels of transforming growth factor (TGF-β accompanied by reduced Notch signaling. Pro-inflammatory cytokines are also upregulated in aging, which led us hypothesize that they might potentially contribute to impaired regeneration in sarcopenia. Thus, in this study, we further analyzed the muscle differentiation-inhibition pathway mediated by pro-inflammatory cytokines in human skeletal muscle cells (HuSKMCs. Methods We studied the modulation of HuSKMC differentiation by the pro-inflammatory cytokines interleukin (IL-1α and tumor necrosis factor (TNF-α The grade of differentiation was determined by either imaging (fusion index or creatine kinase (CK activity, a marker of muscle differentiation. Secretion of TGF-β proteins during differentiation was assessed by using a TGF-β-responsive reporter-gene assay and further identified by means of pharmacological and genetic inhibitors. In addition, signaling events were monitored by western blotting and reverse transcription PCR, both in HuSKMC cultures and in samples from a rat sarcopenia study. Results The pro-inflammatory cytokines IL-1α and TNF-α block differentiation of human myoblasts into myotubes. This anti-differentiation effect requires activation of TGF-β-activated kinase (TAK-1. Using pharmacological and genetic inhibitors, the TAK-1 pathway could be traced to p38 and NFκB. Surprisingly, the anti-differentiation effect of the cytokines required the transcriptional upregulation of Activin A, which in turn acted through its established signaling pathway: ActRII/ALK/SMAD. Inhibition of Activin A signaling was

  17. HGF potentiates extracellular matrix-driven migration of human myoblasts: involvement of matrix metalloproteinases and MAPK/ERK pathway.

    Science.gov (United States)

    González, Mariela Natacha; de Mello, Wallace; Butler-Browne, Gillian S; Silva-Barbosa, Suse Dayse; Mouly, Vincent; Savino, Wilson; Riederer, Ingo

    2017-10-10

    The hepatocyte growth factor (HGF) is required for the activation of muscle progenitor cells called satellite cells (SC), plays a role in the migration of proliferating SC (myoblasts), and is present as a soluble factor during muscle regeneration, along with extracellular matrix (ECM) molecules. In this study, we aimed at determining whether HGF is able to interact with ECM proteins, particularly laminin 111 and fibronectin, and to modulate human myoblast migration. We evaluated the expression of the HGF-receptor c-Met, laminin, and fibronectin receptors by immunoblotting, flow cytometry, or immunofluorescence and used Transwell assays to analyze myoblast migration on laminin 111 and fibronectin in the absence or presence of HGF. Zymography was used to check whether HGF could modulate the production of matrix metalloproteinases by human myoblasts, and the activation of MAPK/ERK pathways was evaluated by immunoblotting. We demonstrated that human myoblasts express c-Met, together with laminin and fibronectin receptors. We observed that human laminin 111 and fibronectin have a chemotactic effect on myoblast migration, and this was synergistically increased when low doses of HGF were added. We detected an increase in MMP-2 activity in myoblasts treated with HGF. Conversely, MMP-2 inhibition decreased the HGF-associated stimulation of cell migration triggered by laminin or fibronectin. HGF treatment also induced in human myoblasts activation of MAPK/ERK pathways, whose specific inhibition decreased the HGF-associated stimulus of cell migration triggered by laminin 111 or fibronectin. We demonstrate that HGF induces ERK phosphorylation and MMP production, thus stimulating human myoblast migration on ECM molecules. Conceptually, these data state that the mechanisms involved in the migration of human myoblasts comprise both soluble and insoluble moieties. This should be taken into account to optimize the design of therapeutic cell transplantation strategies by improving

  18. Impact of static magnetic fields on human myoblast cell cultures.

    Science.gov (United States)

    Stern-Straeter, Jens; Bonaterra, Gabriel Alejandro; Kassner, Stefan S; Faber, Anne; Sauter, Alexander; Schulz, Johannes D; Hörmann, Karl; Kinscherf, Ralf; Goessler, Ulrich Reinhart

    2011-12-01

    Treatment of skeletal muscle loss due to trauma or tumor ablation therapy still lacks a suitable clinical approach. Creation of functional muscle tissue in vitro using the differentiation potential of human satellite cells (myoblasts) is a promising new research field called tissue engineering. Strong differentiation stimuli, which can induce formation of myofibers after cell expansion, have to be identified and evaluated in order to create sufficient amounts of neo-tissue. The objective of this study was to determine the influence of static magnetic fields (SMF) on human satellite cell cultures as one of the preferred stem cell sources in skeletal muscle tissue engineering. Experiments were performed using human satellite cells with and without SMF stimulation after incubation with a culture medium containing low [differentiation medium (DM)] or high [growth medium (GM)] concentrations of growth factors. Proliferation analysis using the alamarBlue assay revealed no significant influence of SMF on cell division. Real-time RT-PCR of the following marker genes was investigated: myogenic factor 5 (MYF5), myogenic differentiation antigen 1 (MYOD1), myogenin (MYOG), skeletal muscle α1 actin (ACTA1), and embryonic (MYH3), perinatal (MYH8) and adult (MYH1) skeletal muscle myosin heavy chain. We detected an influence on marker gene expression by SMF in terms of a down-regulation of the marker genes in cell cultures treated with SMF and DM, but not in cell cultures treated with SMF and GM. Immunocytochemical investigations using antibodies directed against the differentiation markers confirmed the gene expression results and showed an enhancement of maturation after stimulation with GM and SMF. Additional calculation of the fusion index also revealed an increase in myotube formation in cell cultures treated with SMF and GM. Our findings show that the effect of SMF on the process of differentiation depends on the growth factor concentration in the culture medium in human

  19. Black ginseng activates Akt signaling, thereby enhancing myoblast differentiation and myotube growth

    Directory of Open Access Journals (Sweden)

    Soo-Yeon Lee

    2018-01-01

    Conclusion: BG enhances myoblast differentiation and myotube hypertrophy by activating Akt/mTOR/p70S6k axis. Thus, our study demonstrates that BG has promising potential to treat or prevent muscle loss related to aging or other pathological conditions, such as diabetes.

  20. c-MET regulates myoblast motility and myocyte fusion during adult skeletal muscle regeneration.

    Science.gov (United States)

    Webster, Micah T; Fan, Chen-Ming

    2013-01-01

    Adult muscle stem cells, satellite cells (SCs), endow skeletal muscle with tremendous regenerative capacity. Upon injury, SCs activate, proliferate, and migrate as myoblasts to the injury site where they become myocytes that fuse to form new muscle. How migration is regulated, though, remains largely unknown. Additionally, how migration and fusion, which both require dynamic rearrangement of the cytoskeleton, might be related is not well understood. c-MET, a receptor tyrosine kinase, is required for myogenic precursor cell migration into the limb for muscle development during embryogenesis. Using a genetic system to eliminate c-MET function specifically in adult mouse SCs, we found that c-MET was required for muscle regeneration in response to acute muscle injury. c-MET mutant myoblasts were defective in lamellipodia formation, had shorter ranges of migration, and migrated slower compared to control myoblasts. Surprisingly, c-MET was also required for efficient myocyte fusion, implicating c-MET in dual functions of regulating myoblast migration and myocyte fusion.

  1. Novel lncRNAs in myogenesis: a miR-31 overlapping transcript controls myoblast differentiation.

    KAUST Repository

    Ballarino, Monica

    2014-12-15

    Transcriptome analysis allowed the identification of new long noncoding RNAs differentially expressed during murine myoblast differentiation. These transcripts were classified on the basis of their expression under proliferating versus differentiated conditions, muscle-restricted activation, and subcellular localization. Several species displayed preferential expression in dystrophic (mdx) versus wild-type muscles, indicating their possible link with regenerative processes. One of the identified transcripts, lnc-31, even if originating from the same nuclear precursor of miR-31, is produced by a pathway mutually exclusive. We show that lnc-31 and its human homologue hsa-lnc-31 are expressed in proliferating myoblasts, where they counteract differentiation. In line with this, both species are more abundant in mdx muscles and in human Duchenne muscular dystrophy (DMD) myoblasts, than in their normal counterparts. Altogether, these data suggest a crucial role for lnc-31 in controlling the differentiation commitment of precursor myoblasts and indicate that its function is maintained in evolution despite the poor sequence conservation with the human counterpart.

  2. A new level of plasticity: Drosophila smooth-like testes muscles compensate failure of myoblast fusion.

    Science.gov (United States)

    Kuckwa, Jessica; Fritzen, Katharina; Buttgereit, Detlev; Rothenbusch-Fender, Silke; Renkawitz-Pohl, Renate

    2016-01-15

    The testis of Drosophila resembles an individual testis tubule of mammals. Both are surrounded by a sheath of smooth muscles, which in Drosophila are multinuclear and originate from a pool of myoblasts that are set aside in the embryo and accumulate on the genital disc later in development. These muscle stem cells start to differentiate early during metamorphosis and give rise to all muscles of the inner male reproductive system. Shortly before the genital disc and the developing testes connect, multinuclear nascent myotubes appear on the anterior tips of the seminal vesicles. Here, we show that adhesion molecules are distinctly localized on the seminal vesicles; founder cell (FC)-like myoblasts express Dumbfounded (Duf) and Roughest (Rst), and fusion-competent myoblast (FCM)-like cells mainly express Sticks and stones (Sns). The smooth but multinuclear myotubes of the testes arose by myoblast fusion. RNAi-mediated attenuation of Sns or both Duf and Rst severely reduced the number of nuclei in the testes muscles. Duf and Rst probably act independently in this context. Despite reduced fusion in all of these RNAi-treated animals, myotubes migrated onto the testes, testes were shaped and coiled, muscle filaments were arranged as in the wild type and spermatogenesis proceeded normally. Hence, the testes muscles compensate for fusion defects so that the myofibres encircling the adult testes are indistinguishable from those of the wild type and male fertility is guaranteed. © 2016. Published by The Company of Biologists Ltd.

  3. DRAGON, a GPI-anchored membrane protein, inhibits BMP signaling in C2C12 myoblasts.

    Science.gov (United States)

    Kanomata, Kazuhiro; Kokabu, Shoichiro; Nojima, Junya; Fukuda, Toru; Katagiri, Takenobu

    2009-06-01

    Bone morphogenetic proteins (BMPs) induce osteoblastic differentiation of myoblasts via binding to cell surface receptors. Repulsive guidance molecules (RGMs) have been identified as BMP co-receptors. We report here that DRAGON/RGMb, a member of the RGM family, suppressed BMP signaling in C2C12 myoblasts via a novel mechanism. All RGMs were expressed in C2C12 cells that were differentiated into myocytes and osteoblastic cells, but RGMc was not detected in immature cells. In C2C12 cells, only DRAGON suppressed ALP and Id1 promoter activities induced by BMP-4 or by constitutively activated BMP type I receptors. This inhibition by DRAGON was dependent on the secretory form of the von Willbrand factor type D domain. DRAGON even suppressed BMP signaling induced by constitutively activated Smad1. Over-expression of neogenin did not alter the inhibitory capacity of DRAGON. Taken together, these findings indicate that DRAGON may be an inhibitor of BMP signaling in C2C12 myoblasts. We also suggest that a novel molecule(s) expressed on the cell membrane may mediate the signal transduction of DRAGON in order to suppress BMP signaling in C2C12 myoblasts.

  4. Electrotransfection and lipofection show comparable efficiency for in vitro gene delivery of primary human myoblasts.

    Science.gov (United States)

    Mars, Tomaz; Strazisar, Marusa; Mis, Katarina; Kotnik, Nejc; Pegan, Katarina; Lojk, Jasna; Grubic, Zoran; Pavlin, Mojca

    2015-04-01

    Transfection of primary human myoblasts offers the possibility to study mechanisms that are important for muscle regeneration and gene therapy of muscle disease. Cultured human myoblasts were selected here because muscle cells still proliferate at this developmental stage, which might have several advantages in gene therapy. Gene therapy is one of the most sought-after tools in modern medicine. Its progress is, however, limited due to the lack of suitable gene transfer techniques. To obtain better insight into the transfection potential of the presently used techniques, two non-viral transfection methods--lipofection and electroporation--were compared. The parameters that can influence transfection efficiency and cell viability were systematically approached and compared. Cultured myoblasts were transfected with the pEGFP-N1 plasmid either using Lipofectamine 2000 or with electroporation. Various combinations for the preparation of the lipoplexes and the electroporation media, and for the pulsing protocols, were tested and compared. Transfection efficiency and cell viability were inversely proportional for both approaches. The appropriate ratio of Lipofectamine and plasmid DNA provides optimal conditions for lipofection, while for electroporation, RPMI medium and a pulsing protocol using eight pulses of 2 ms at E = 0.8 kV/cm proved to be the optimal combination. The transfection efficiencies for the optimal lipofection and optimal electrotransfection protocols were similar (32 vs. 32.5%, respectively). Both of these methods are effective for transfection of primary human myoblasts; however, electroporation might be advantageous for in vivo application to skeletal muscle.

  5. Analysis of Mitochondrial Network Morphology in Cultured Myoblasts from Patients with Mitochondrial Disorders

    Czech Academy of Sciences Publication Activity Database

    Sládková, J.; Spáčilová, J.; Čapek, Martin; Tesařová, M.; Hansíková, H.; Honzík, T.; Martínek, J.; Zámečník, J.; Kostková, O.; Zeman, J.

    2015-01-01

    Roč. 39, č. 5 (2015), s. 340-350 ISSN 0191-3123 R&D Projects: GA ČR(CZ) GB14-36804G; GA MŠk(CZ) LH13028 Institutional support: RVO:67985823 Keywords : cristae * Fiji * image analysis * mitochondrial disorders * myoblasts * ultrastructure Subject RIV: EA - Cell Biology Impact factor: 0.828, year: 2015

  6. Developmental Programming in Response to Intrauterine Growth Restriction Impairs Myoblast Function and Skeletal Muscle Metabolism

    Directory of Open Access Journals (Sweden)

    D. T. Yates

    2012-01-01

    Full Text Available Fetal adaptations to placental insufficiency alter postnatal metabolic homeostasis in skeletal muscle by reducing glucose oxidation rates, impairing insulin action, and lowering the proportion of oxidative fibers. In animal models of intrauterine growth restriction (IUGR, skeletal muscle fibers have less myonuclei at birth. This means that myoblasts, the sole source for myonuclei accumulation in fibers, are compromised. Fetal hypoglycemia and hypoxemia are complications that result from placental insufficiency. Hypoxemia elevates circulating catecholamines, and chronic hypercatecholaminemia has been shown to reduce fetal muscle development and growth. We have found evidence for adaptations in adrenergic receptor expression profiles in myoblasts and skeletal muscle of IUGR sheep fetuses with placental insufficiency. The relationship of β-adrenergic receptors shifts in IUGR fetuses because Adrβ2 expression levels decline and Adrβ1 expression levels are unaffected in myofibers and increased in myoblasts. This adaptive response would suppress insulin signaling, myoblast incorporation, fiber hypertrophy, and glucose oxidation. Furthermore, this β-adrenergic receptor expression profile persists for at least the first month in IUGR lambs and lowers their fatty acid mobilization. Developmental programming of skeletal muscle adrenergic receptors partially explains metabolic and endocrine differences in IUGR offspring, and the impact on metabolism may result in differential nutrient utilization.

  7. Characterization of heterokaryons between skeletal myoblasts and somatic cells formed by fusion with HVJ (Sendai virus); effects on myogenic differentiation.

    Science.gov (United States)

    Hirayama, E; Udaka, Y; Kawai, T; Kim, J

    2001-02-01

    In skeletal myogenic differentiation, myoblasts fuse with myogenic cells spontaneously, but do not fuse with non-myogenic cells either in vivo or in vitro, suggesting that the fusion of myoblasts with non-myogenic cells is unsuitable for differentiation. To understand the inevitability of the fusion among myoblasts, we prepared heterokaryons in crosses between quail myoblasts transformed with a temperature-sensitive mutant of Rous sarcoma virus (QM-RSV cells) and rodent non-myogenic cells, such as tumor cells, fibroblasts, or neurogenic cells by HVJ (Sendai virus) and examined how myogenic differentiation was influenced in the prepared heterokaryons, focusing on myogenin expression and myofibril formation as markers of differentiation. When presumptive QM-RSV cells were fused with non-myogenic cells by HVJ and induced to differentiate, both myogenin expression and myofibril formation were suppressed. When myotubes of QM-RSV cells that had already expressed myogenin and formed myofibrils were fused with non-myogenic cells, both myogenin and myofibrils disappeared. Especially, fibrous structures of myofibrils were significantly lost and dots or aggregations of F-actin were formed within 24 hr after formation of heterokaryons. However, the fusion of presumptive or differentiated QM-RSV cells with rodent myoblasts did not disturb myogenin expression or myofibril formation. These results suggest that mutual fusion of myoblasts is indispensable for normal myogenic differentiation irrespective of the species, and that some factors inhibiting myogenic differentiation exist in the cytoplasm of non-myogenic cells, but not in myoblasts.

  8. Geigerin-induced cytotoxicity in a murine myoblast cell line (C2C12

    Directory of Open Access Journals (Sweden)

    Christo J. Botha

    2017-01-01

    Full Text Available Geigeria poisoning in sheep, locally known as ‘vermeersiekte’, is an economically important plant poisoning in southern Africa. The toxic principles contained by the toxic plants are believed to be several sesquiterpene lactones, such as geigerin, vermeeric acid and vermeerin, which cause striated muscle lesions in small stock. Because of ethical issues surrounding the use of live animals in toxicity studies, there is currently a dire need to establish an in vitro model that can be used to replace traditional animal experimentation. The objective of this study was to determine the cytotoxicity of geigerin in a murine myoblast cell line (C2C12 using methyl-thiazol-tetrazolium (MTT and lactate dehydrogenase (LDH assays, annexin V and propidium iodide (PI flow cytometry and transmission electron microscopy (TEM. Mouse myoblasts were exposed to 2.0 mM, 2.5 mM and 5.0 mM geigerin for 24, 48 and 72 h. A concentration-dependent cytotoxic response was observed. Apoptosis was detected by means of annexin V flow cytometry during the first 24 h and apoptotic bodies were also visible on TEM. According to the LDH and PI flow cytometry results, myoblast cell membranes were not injured. We concluded that the murine myoblast cell line (C2C12 is a suitable model for future studies planned to evaluate the cytotoxicity of other and combinations of sesquiterpene lactones, with and without metabolic activation, implicated in ‘vermeersiekte’ and to elucidate the subcellular effects of these myotoxins on cultured myoblasts.

  9. Laminin-Coated Poly(Methyl Methacrylate) (PMMA) Nanofiber Scaffold Facilitates the Enrichment of Skeletal Muscle Myoblast Population

    National Research Council Canada - National Science Library

    Nor Kamalia Zahari; Ruszymah Binti Haji Idrus; Shiplu Roy Chowdhury

    2017-01-01

    .... To overcome these limitations, this study was carried out to establish a 3D culture environment using nanofiber scaffolds to enrich the myoblast population during construct formation. Poly(methyl methacrylate) (PMMA) nanofiber (PM...

  10. Tocotrienol-Rich Fraction Ameliorates Antioxidant Defense Mechanisms and Improves Replicative Senescence-Associated Oxidative Stress in Human Myoblasts

    Directory of Open Access Journals (Sweden)

    Shy Cian Khor

    2017-01-01

    Full Text Available During aging, oxidative stress affects the normal function of satellite cells, with consequent regeneration defects that lead to sarcopenia. This study aimed to evaluate tocotrienol-rich fraction (TRF modulation in reestablishing the oxidative status of myoblasts during replicative senescence and to compare the effects of TRF with other antioxidants (α-tocopherol (ATF and N-acetyl-cysteine (NAC. Primary human myoblasts were cultured to young, presenescent, and senescent phases. The cells were treated with antioxidants for 24 h, followed by the assessment of free radical generation, lipid peroxidation, antioxidant enzyme mRNA expression and activities, and the ratio of reduced to oxidized glutathione. Our data showed that replicative senescence increased reactive oxygen species (ROS generation and lipid peroxidation in myoblasts. Treatment with TRF significantly diminished ROS production and decreased lipid peroxidation in senescent myoblasts. Moreover, the gene expression of superoxide dismutase (SOD2, catalase (CAT, and glutathione peroxidase (GPX1 was modulated by TRF treatment, with increased activity of superoxide dismutase and catalase and reduced glutathione peroxidase in senescent myoblasts. In comparison to ATF and NAC, TRF was more efficient in heightening the antioxidant capacity and reducing free radical insults. These results suggested that TRF is able to ameliorate antioxidant defense mechanisms and improves replicative senescence-associated oxidative stress in myoblasts.

  11. Cargo delivery to adhering myoblast cells from liposome-containing poly(dopamine) composite coatings

    DEFF Research Database (Denmark)

    Madsen, Martin Elias Lynge; Mian Teo, Boon; Laursen, Marie Bækgaard

    2013-01-01

    fluorescence over time reveals a decrease in both parameters over 48 h. Our results demonstrate the ability to affect the cell response depending on the properties of the films, opening up a variety of opportunities for biomedical applications in substrate-mediated drug delivery....... a quartz crystal microbalance with dissipation. We assess the response of adhering myoblast cells to these films containing fluorescent lipids in terms of uptake efficiency and cell mean fluorescence using flow cytometry. The viability of adhering myoblast cells, when the hydrophobic cytotoxic compound...... thiocoraline is entrapped in the lipid membrane, is assessed for different films. Coatings with one or two liposome deposition steps are considered. Further, the effect of the polymer separation layers between the liposome layers is determined. We found that it is possible to use the different nano...

  12. In vitro culture of primary human myoblasts by using the dextran microcarriers Cytodex3®.

    Science.gov (United States)

    Rozwadowska, Natalia; Malcher, Agnieszka; Baumann, Ewa; Kolanowski, Tomasz Jan; Rucinski, Marek; Mietkiewski, Tomasz; Fiedorowicz, Katarzyna; Kurpisz, Maciej

    2016-01-01

    Primary cells in vitro culture scale-up is a crucial issue in cell-based tissue and organ regeneration therapy. Reducing costs and space occupied by the cells cultured in vitro has been an important target. Cells cultured in vitro with the use of bioreactor with dextran microcarriers (Cytodex®) have potentially a chance to meet many of the cell therapy requirements. We used collagen-coated carriers (Cytodex3®) and a spinner flask bioreactor to develop environment suitable for human myoblast proliferation. In parallel, standard adherent in vitro culture conditions for myoblasts propagation (T-flask) were conducted. Cell cycle characterization, senescence, myogenic gene ex-pression and cell apoptosis were evaluated in order to find differences between two culture systems under study. The number of cells obtained in bioreactor per 106 of starting cells population was approximately ten times lower in comparison with T-flask culture system. The microcarriers cultured adult myoblasts in compari-son with the regular T-flask culture showed faster and more advanced replicative aging and lower proliferative potential. Moreover, the percentage of the cells that entailed an irreversible cell arrest (G0 phase) was also significantly (p < 0.0001) increased. Our results suggest that population of primary human myoblasts obtained from adult individuals and propagated on dextran microcarriers did not meet the requirements of the regenerative medicine regarding quantity and quality of the cells obtained. Nonetheless, further optimization of the cell scaling up process including both microcarriers and/or bioreactor program is still an important option.

  13. Protein kinase D2 is an essential regulator of murine myoblast differentiation.

    Directory of Open Access Journals (Sweden)

    Alexander Kleger

    Full Text Available Muscle differentiation is a highly conserved process that occurs through the activation of quiescent satellite cells whose progeny proliferate, differentiate, and fuse to generate new myofibers. A defined pattern of myogenic transcription factors is orchestrated during this process and is regulated via distinct signaling cascades involving various intracellular signaling pathways, including members of the protein kinase C (PKC family. The protein kinase D (PKD isoenzymes PKD1, -2, and -3, are prominent downstream targets of PKCs and phospholipase D in various biological systems including mouse and could hence play a role in muscle differentiation. In the present study, we used a mouse myoblast cell line (C2C12 as an in vitro model to investigate the role of PKDs, in particular PKD2, in muscle stem cell differentiation. We show that C2C12 cells express all PKD isoforms with PKD2 being highly expressed. Furthermore, we demonstrate that PKD2 is specifically phosphorylated/activated during the initiation of mouse myoblast differentiation. Selective inhibition of PKCs or PKDs by pharmacological inhibitors blocked myotube formation. Depletion of PKD2 by shRNAs resulted in a marked inhibition of myoblast cell fusion. PKD2-depleted cells exhibit impaired regulation of muscle development-associated genes while the proliferative capacity remains unaltered. Vice versa forced expression of PKD2 increases myoblast differentiation. These findings were confirmed in primary mouse satellite cells where myotube fusion was also decreased upon inhibition of PKDs. Active PKD2 induced transcriptional activation of myocyte enhancer factor 2D and repression of Pax3 transcriptional activity. In conclusion, we identify PKDs, in particular PKD2, as a major mediator of muscle cell differentiation in vitro and thereby as a potential novel target for the modulation of muscle regeneration.

  14. The Mouse C2C12 Myoblast Cell Surface N-Linked Glycoproteome

    OpenAIRE

    Gundry, Rebekah L.; Raginski, Kimberly; Tarasova, Yelena; Tchernyshyov, Irina; Bausch-Fluck, Damaris; Elliott, Steven T.; Boheler, Kenneth R.; Van Eyk, Jennifer E.; Wollscheid, Bernd

    2009-01-01

    Endogenous regeneration and repair mechanisms are responsible for replacing dead and damaged cells to maintain or enhance tissue and organ function, and one of the best examples of endogenous repair mechanisms involves skeletal muscle. Although the molecular mechanisms that regulate the differentiation of satellite cells and myoblasts toward myofibers are not fully understood, cell surface proteins that sense and respond to their environment play an important role. The cell surface capturing ...

  15. β‐Taxilin participates in differentiation of C2C12 myoblasts into myotubes

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, Hiroshi; Makiyama, Tomohiko; Nogami, Satoru; Horii, Yukimi [Department of Molecular and Cell Biology, Graduate school of Medicine, Dokkyo Medical University, 880 Kitakobayashi, Mibu-town, Tochigi 321-0293 (Japan); Akasaki, Kenji [Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Fukuyama, Hiroshima 729-0292 (Japan); Shirataki, Hiromichi, E-mail: hiro-sh@dokkyomed.ac.jp [Department of Molecular and Cell Biology, Graduate school of Medicine, Dokkyo Medical University, 880 Kitakobayashi, Mibu-town, Tochigi 321-0293 (Japan)

    2016-07-15

    Myogenesis is required for the development of skeletal muscle. Accumulating evidence indicates that the expression of several genes are upregulated during myogenesis and these genes play pivotal roles in myogenesis. However, the molecular mechanism underlying myogenesis is not fully understood. In this study, we found that β-taxilin, which is specifically expressed in the skeletal muscle and heart tissues, was progressively expressed during differentiation of C2C12 myoblasts into myotubes, prompting us to investigate the role of β-taxilin in myogenesis. In C2C12 cells, knockdown of β-taxilin impaired the fusion of myoblasts into myotubes, and decreased the diameter of myotubes. We also found that β-taxilin interacted with dysbindin, a coiled-coil-containing protein. Knockdown of dysbindin conversely promoted the fusion of myoblasts into myotubes and increased the diameter of myotubes in C2C12 cells. Furthermore, knockdown of dysbindin attenuated the inhibitory effect of β-taxilin depletion on myotube formation of C2C12 cells. These results demonstrate that β-taxilin participates in myogenesis through suppressing the function of dysbindin to inhibit the differentiation of C2C12 myoblasts into myotubes. - Highlights: • β‐Taxilin is progressively expressed during differentiation of C2C12 cell. • Knockdown of β-taxilin impaired C2C12 myotube formation. • β‐Taxilin interacted with dysbindin. • Knockdown of dysbindin promoted C2C12 myotube formation. • The function of β-taxilin in C2C12 myotube formation depends on dysbindin.

  16. Stimulated myoblast differentiation on graphene oxide-impregnated PLGA-collagen hybrid fibre matrices.

    Science.gov (United States)

    Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Kim, Yong-Joo; Hyun, Jung Keun; Jung, Tae-Gon; Hong, Suck Won; Han, Dong-Wook

    2015-03-12

    Electrospinning is a simple and effective method for fabricating micro- and nanofiber matrices. Electrospun fibre matrices have numerous advantages for use as tissue engineering scaffolds, such as high surface area-to-volume ratio, mass production capability and structural similarity to the natural extracellular matrix (ECM). Therefore, electrospun matrices, which are composed of biocompatible polymers and various biomaterials, have been developed as biomimetic scaffolds for the tissue engineering applications. In particular, graphene oxide (GO) has recently been considered as a novel biomaterial for skeletal muscle regeneration because it can promote the growth and differentiation of myoblasts. Therefore, the aim of the present study was to fabricate the hybrid fibre matrices that stimulate myoblasts differentiation for skeletal muscle regeneration. Hybrid fibre matrices composed of poly(lactic-co-glycolic acid, PLGA) and collagen (Col) impregnated with GO (GO-PLGA-Col) were successfully fabricated using an electrospinning process. Our results indicated that the GO-PLGA-Col hybrid matrices were comprised of randomly-oriented continuous fibres with a three-dimensional non-woven porous structure. Compositional analysis showed that GO was dispersed uniformly throughout the GO-PLGA-Col matrices. In addition, the hydrophilicity of the fabricated matrices was significantly increased by blending with a small amount of Col and GO. The attachment and proliferation of the C2C12 skeletal myoblasts were significantly enhanced on the GO-PLGA-Col hybrid matrices. Furthermore, the GO-PLGA-Col matrices stimulated the myogenic differentiation of C2C12 skeletal myoblasts, which was enhanced further under the culture conditions of the differentiation media. Taking our findings into consideration, it is suggested that the GO-PLGA-Col hybrid fibre matrices can be exploited as potential biomimetic scaffolds for skeletal tissue engineering and regeneration because these GO

  17. Leonurine (SCM-198) improves cardiac recovery in rat during chronic infarction.

    Science.gov (United States)

    Liu, XinHua; Pan, LiLong; Gong, QiHai; Zhu, YiZhun

    2010-12-15

    Leonurine, an alkaloid typically found in Herba leonuri, is known to have both antioxidant and cardioprotective properties. In the present study, we investigated the cardioprotective mechanism of leonurine the in vivo rat model of chronic myocardial ischemia and in vitro H9c2 cardiac myocyte model of oxidative stress. Myocardial ischemia was induced by ligating the left anterior descending coronary artery. Rats were divided into sham, myocardial ischemia+saline, and myocardial ischemia+leonurine (15 mg/kg/day). Cardiac function was recorded by catheterization. Apoptosis-related factor vascular endothelial growth factor (VEGF), survivin, Bcl-2 and Bax and pro-survival signaling pathways Akt, hypoxia inducible factor (HIF)-1α were measured by Western blotting or RT-PCR. Our results showed leonurine significantly improved myocardial function as evidenced by the decreased left ventricle end-diastolic pressure and the increased +dP/dt. Interestingly, leonurine increased the phosphorylation of Akt, the protein and gene expression of Bcl-2, but it reduced the protein and gene expression of Bax in vivo. Meanwhile leonurine significantly increased Akt phosphorylation in a concentration-dependent manner in H9c2 cardiac myocyte induced by oxidative stress in vitro, which was abolished by a phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. Furthermore, leonurine not only increased the expression of HIF-1α but also the expression of survivin and VEGF. The results of present study demonstrated, for the first time that leonurine has potent anti-apoptotic effects after chronic myocardial ischemia mediated by activating the PI3K/Akt signaling pathway. Angiogenic mechanisms may be partially responsible for such an effect, which needs to be studied further. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. PKC-Mediated ZYG1 Phosphorylation Induces Fusion of Myoblasts as well as of Dictyostelium Cells

    Science.gov (United States)

    Amagai, Aiko; MacWilliams, Harry; Isono, Takahiro; Omatsu-Kanbe, Mariko; Urano, Shinya; Yamamoto, Kazuo; Maeda, Yasuo

    2012-01-01

    We have previously demonstrated that a novel protein ZYG1 induces sexual cell fusion (zygote formation) of Dictyostelium cells. In the process of cell fusion, involvements of signal transduction pathways via Ca2+ and PKC (protein kinase C) have been suggested because zygote formation is greatly enhanced by PKC activators. In fact, there are several deduced sites phosphorylated by PKC in ZYG1 protein. Thereupon, we designed the present work to examine whether or not ZYG1 is actually phosphorylated by PKC and localized at the regions of cell-cell contacts where cell fusion occurs. These were ascertained, suggesting that ZYG1 might be the target protein for PKC. A humanized version of zyg1 cDNA (mzyg1) was introduced into myoblasts to know if ZYG1 is also effective in cell fusion of myoblasts. Quite interestingly, enforced expression of ZYG1 in myoblasts was found to induce markedly their cell fusion, thus strongly suggesting the existence of a common signaling pathway for cell fusion beyond the difference of species. PMID:22505931

  19. Heterogeneous activation of a slow myosin gene in proliferating myoblasts and differentiated single myofibers.

    Science.gov (United States)

    Wang, Jing-Hua; Wang, Qiao-Jing; Wang, Chao; Reinholt, Brad; Grant, Alan L; Gerrard, David E; Kuang, Shihuan

    2015-06-01

    Each skeletal muscle contains a fixed ratio of fast and slow myofibers that are distributed in a stereotyped pattern to achieve a specific motor function. How myofibers are specified during development and regeneration is poorly understood. Here we address this question using transgenic reporter mice that indelibly mark the myofiber lineages based on activation of fast or slow myosin. Lineage tracing indicates that during development all muscles have activated the fast myosin gene Myl1, but not the slow myosin gene Myh7, which is activated in all slow but a subset of fast myofibers. Similarly, most nascent myofibers do not activate Myh7 during fast muscle regeneration, but the ratio and pattern of fast and slow myofibers are restored at the completion of regeneration. At the single myofiber level, most mature fast myofibers are heterogeneous in nuclear composition, manifested by mosaic activation of Myh7. Strikingly, Myh7 is activated in a subpopulation of proliferating myoblasts that co-express the myogenic progenitor marker Pax7. When induced to differentiate, the Myh7-activated myoblasts differentiate more readily than the non-activated myoblasts, and have a higher tendency, but not restricted, to become slow myotubes. Together, our data reveal significant nuclear heterogeneity within a single myofiber, and challenge the conventional view that myosin genes are only expressed after myogenic differentiation. These results provide novel insights into the regulation of muscle fiber type specification. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Hes6 is required for actin cytoskeletal organization in differentiating C2C12 myoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Malone, Caroline M.P.; Domaschenz, Renae; Amagase, Yoko [MRC Cancer Cell Unit, Hutchison-MRC Research Centre, Addenbrooke' s Hospital, Cambridge CB2 0XZ (United Kingdom); Dunham, Ian [EMBL-European Bioinformatics Institute (EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD (United Kingdom); Murai, Kasumi [MRC Cancer Cell Unit, Hutchison-MRC Research Centre, Addenbrooke' s Hospital, Cambridge CB2 0XZ (United Kingdom); Jones, Philip H., E-mail: phj20@cam.ac.uk [MRC Cancer Cell Unit, Hutchison-MRC Research Centre, Addenbrooke' s Hospital, Cambridge CB2 0XZ (United Kingdom)

    2011-07-01

    Hes6 is a member of the hairy-enhancer-of-split family of transcription factors that regulate proliferating cell fate in development and is known to be expressed in developing muscle. Here we investigate its function in myogenesis in vitro. We show that Hes6 is a direct transcriptional target of the myogenic transcription factors MyoD and Myf5, indicating that it is integral to the myogenic transcriptional program. The localization of Hes6 protein changes during differentiation, becoming predominantly nuclear. Knockdown of Hes6 mRNA levels by siRNA has no effect on cell cycle exit or induction of myosin heavy chain expression in differentiating C2C12 myoblasts, but F-actin filament formation is disrupted and both cell motility and myoblast fusion are reduced. The knockdown phenotype is rescued by expression of Hes6 cDNA resistant to siRNA. These results define a novel role for Hes6 in actin cytoskeletal dynamics in post mitotic myoblasts.

  1. PKC-Mediated ZYG1 Phosphorylation Induces Fusion of Myoblasts as well as of Dictyostelium Cells

    Directory of Open Access Journals (Sweden)

    Aiko Amagai

    2012-01-01

    Full Text Available We have previously demonstrated that a novel protein ZYG1 induces sexual cell fusion (zygote formation of Dictyostelium cells. In the process of cell fusion, involvements of signal transduction pathways via Ca2+ and PKC (protein kinase C have been suggested because zygote formation is greatly enhanced by PKC activators. In fact, there are several deduced sites phosphorylated by PKC in ZYG1 protein. Thereupon, we designed the present work to examine whether or not ZYG1 is actually phosphorylated by PKC and localized at the regions of cell-cell contacts where cell fusion occurs. These were ascertained, suggesting that ZYG1 might be the target protein for PKC. A humanized version of zyg1 cDNA (mzyg1 was introduced into myoblasts to know if ZYG1 is also effective in cell fusion of myoblasts. Quite interestingly, enforced expression of ZYG1 in myoblasts was found to induce markedly their cell fusion, thus strongly suggesting the existence of a common signaling pathway for cell fusion beyond the difference of species.

  2. Targeted Gene Addition of Microdystrophin in Mice Skeletal Muscle via Human Myoblast Transplantation

    Directory of Open Access Journals (Sweden)

    Basma F Benabdallah

    2013-01-01

    Full Text Available Zinc finger nucleases (ZFN can facilitate targeted gene addition to the genome while minimizing the risks of insertional mutagenesis. Here, we used a previously characterized ZFN pair targeting the chemokine (C-C motif receptor 5 (CCR5 locus to introduce, as a proof of concept, the enhanced green fluorescent protein (eGFP or the microdystrophin genes into human myoblasts. Using integrase-defective lentiviral vectors (IDLVs and chimeric adenoviral vectors to transiently deliver template DNA and ZFN respectively, we achieved up to 40% targeted gene addition in human myoblasts. When the O6-methylguanine-DNA methyltransferaseP140K gene was co-introduced with eGFP, the frequency of cells with targeted integration could be increased to over 90% after drug selection. Importantly, gene-targeted myoblasts retained their mitogenic activity and potential to form myotubes both in vitro and in vivo when injected into the tibialis anterior of immune-deficient mice. Altogether, our results could lead to the development of improved cell therapy transplantation protocols for muscular diseases.

  3. The mouse C2C12 myoblast cell surface N-linked glycoproteome: identification, glycosite occupancy, and membrane orientation.

    Science.gov (United States)

    Gundry, Rebekah L; Raginski, Kimberly; Tarasova, Yelena; Tchernyshyov, Irina; Bausch-Fluck, Damaris; Elliott, Steven T; Boheler, Kenneth R; Van Eyk, Jennifer E; Wollscheid, Bernd

    2009-11-01

    Endogenous regeneration and repair mechanisms are responsible for replacing dead and damaged cells to maintain or enhance tissue and organ function, and one of the best examples of endogenous repair mechanisms involves skeletal muscle. Although the molecular mechanisms that regulate the differentiation of satellite cells and myoblasts toward myofibers are not fully understood, cell surface proteins that sense and respond to their environment play an important role. The cell surface capturing technology was used here to uncover the cell surface N-linked glycoprotein subproteome of myoblasts and to identify potential markers of myoblast differentiation. 128 bona fide cell surface-exposed N-linked glycoproteins, including 117 transmembrane, four glycosylphosphatidylinositol-anchored, five extracellular matrix, and two membrane-associated proteins were identified from mouse C2C12 myoblasts. The data set revealed 36 cluster of differentiation-annotated proteins and confirmed the occupancy for 235 N-linked glycosylation sites. The identification of the N-glycosylation sites on the extracellular domain of the proteins allowed for the determination of the orientation of the identified proteins within the plasma membrane. One glycoprotein transmembrane orientation was found to be inconsistent with Swiss-Prot annotations, whereas ambiguous annotations for 14 other proteins were resolved. Several of the identified N-linked glycoproteins, including aquaporin-1 and beta-sarcoglycan, were found in validation experiments to change in overall abundance as the myoblasts differentiate toward myotubes. Therefore, the strategy and data presented shed new light on the complexity of the myoblast cell surface subproteome and reveal new targets for the clinically important characterization of cell intermediates during myoblast differentiation into myotubes.

  4. Biological Effect of Licochalcone C on the Regulation of PI3K/Akt/eNOS and NF-?B/iNOS/NO Signaling Pathways in H9c2 Cells in Response to LPS Stimulation

    OpenAIRE

    Franceschelli, Sara; Pesce, Mirko; Ferrone, Alessio; Gatta, Daniela Maria Pia; Patruno, Antonia; de Lutiis, Maria Anna; Quiles, Jos? Luis; Grilli, Alfredo; Felaco, Mario; Speranza, Lorenza

    2017-01-01

    Polyphenols compounds are a group molecules present in many plants. They have antioxidant properties and can also be helpful in the management of sepsis. Licochalcone C (LicoC), a constituent of Glycyrrhiza glabra, has various biological and pharmacological properties. In saying this, the effect of LicoC on the inflammatory response that characterizes septic myocardial dysfunction is poorly understood. The aim of this study was to determine whether LicoC exhibits anti-inflammatory properties ...

  5. Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, K.K. [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP (Brazil); Monteiro, C.J.; Silva, W.; Silva, A.R. [Núcleo de Pesquisa em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG (Brazil); Santos, P.M. [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraíba, São José dos Campos, SP (Brazil); Lima, K.F. [Núcleo de Pesquisa em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG (Brazil); Moraes, K.C.M. [Instituto de Biociências, Departamento de Biologia, Universidade Estadual Paulista ‘‘Júlio de Mesquita Filho’’, Rio Claro, SP (Brazil)

    2013-11-29

    Cardiovascular disease is one of the leading causes of death worldwide, and evidence indicates a correlation between the inflammatory process and cardiac dysfunction. Selective inhibitors of cyclooxygenase-2 (COX-2) enzyme are not recommended for long-term use because of potentially severe side effects to the heart. Considering this and the frequent prescribing of commercial celecoxib, the present study analyzed cellular and molecular effects of 1 and 10 µM celecoxib in a cell culture model. After a 24-h incubation, celecoxib reduced cell viability in a dose-dependent manner as also demonstrated in MTT assays. Furthermore, reverse transcription-polymerase chain reaction analysis showed that the drug modulated the expression level of genes related to death pathways, and Western blot analyses demonstrated a modulatory effect of the drug on COX-2 protein levels in cardiac cells. In addition, the results demonstrated a downregulation of prostaglandin E2 production by the cardiac cells incubated with celecoxib, in a dose-specific manner. These results are consistent with the decrease in cell viability and the presence of necrotic processes shown by Fourier transform infrared analysis, suggesting a direct correlation of prostanoids in cellular homeostasis and survival.

  6. Cellular and molecular studies of the effects of a selective COX-2 inhibitor celecoxib in the cardiac cell line H9c2 and their correlation with death mechanisms

    Directory of Open Access Journals (Sweden)

    K.K. Sakane

    2014-01-01

    Full Text Available Cardiovascular disease is one of the leading causes of death worldwide, and evidence indicates a correlation between the inflammatory process and cardiac dysfunction. Selective inhibitors of cyclooxygenase-2 (COX-2 enzyme are not recommended for long-term use because of potentially severe side effects to the heart. Considering this and the frequent prescribing of commercial celecoxib, the present study analyzed cellular and molecular effects of 1 and 10 µM celecoxib in a cell culture model. After a 24-h incubation, celecoxib reduced cell viability in a dose-dependent manner as also demonstrated in MTT assays. Furthermore, reverse transcription-polymerase chain reaction analysis showed that the drug modulated the expression level of genes related to death pathways, and Western blot analyses demonstrated a modulatory effect of the drug on COX-2 protein levels in cardiac cells. In addition, the results demonstrated a downregulation of prostaglandin E2 production by the cardiac cells incubated with celecoxib, in a dose-specific manner. These results are consistent with the decrease in cell viability and the presence of necrotic processes shown by Fourier transform infrared analysis, suggesting a direct correlation of prostanoids in cellular homeostasis and survival.

  7. NecroX-7 prevents oxidative stress-induced cardiomyopathy by inhibition of NADPH oxidase activity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joonghoon; Park, Eok; Ahn, Bong-Hyun; Kim, Hyoung Jin [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of); Park, Ji-hoon [Department of Biochemistry, School of Medicine, Chungnam National University, Daejeon, 301-747 (Korea, Republic of); Koo, Sun Young; Kwak, Hyo-Shin; Park, Heui Sul; Kim, Dong Wook; Song, Myoungsub; Yim, Hyeon Joo; Seo, Dong Ook [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of); Kim, Soon Ha, E-mail: shakim@lgls.com [LG Life Sciences Ltd., R and D Park, Daejeon, 305-380 (Korea, Republic of)

    2012-08-15

    Oxidative stress is one of the causes of cardiomyopathy. In the present study, NecroXs, novel class of mitochondrial ROS/RNS scavengers, were evaluated for cardioprotection in in vitro and in vivo model, and the putative mechanism of the cardioprotection of NecroX-7 was investigated by global gene expression profiling and subsequent biochemical analysis. NecroX-7 prevented tert-butyl hydroperoxide (tBHP)-induced death of H9C2 rat cardiomyocytes at EC{sub 50} = 0.057 μM. In doxorubicin (DOX)-induced cardiomyopathy in rats, NecroX-7 significantly reduced the plasma levels of creatine kinase (CK-MB) and lactate dehydrogenase (LDH) which were increased by DOX treatment (p < 0.05). Microarray analysis revealed that 21 genes differentially expressed in tBHP-treated H9C2 cells were involved in ‘Production of reactive oxygen species’ (p = 0.022), and they were resolved by concurrent NecroX-7 treatment. Gene-to-gene networking also identified that NecroX-7 relieved cell death through Ncf1/p47phox and Rac2 modulation. In subsequent biochemical analysis, NecroX-7 inhibited NADPH oxidase (NOX) activity by 53.3% (p < 0.001). These findings demonstrate that NecroX-7, in part, provides substantial protection of cardiomyopathy induced by tBHP or DOX via NOX-mediated cell death. -- Highlights: ► NecroX-7 prevented tert-butyl hydroperoxide-induced in vitro cardiac cell death. ► NecroX-7 ameliorated doxorubicin-induced in vivo cardiomyopathy. ► NecroX-7 prevented oxidative stress and necrosis-enriched transcriptional changes. ► NecroX-7 effectively inhibited NADPH oxidase activation. ► Cardioprotection of Necro-7 was brought on by modulation of NADPH oxidase activity.

  8. Folic acid is necessary for proliferation and differentiation of C2C12 myoblasts.

    Science.gov (United States)

    Hwang, Seong Y; Kang, Yong J; Sung, Bokyung; Jang, Jung Y; Hwang, Na L; Oh, Hye J; Ahn, Yu R; Kim, Hong J; Shin, Jin H; Yoo, Mi-Ae; Kim, Cheol M; Chung, Hae Y; Kim, Nam D

    2017-05-04

    Folic acid, a water soluble B vitamin, plays an important role in cellular metabolic activities, such as functioning as a cofactor in one-carbon metabolism for DNA and RNA synthesis as well as nucleotide and amino acid biosynthesis in the body. A lack of dietary folic acid can lead to folic acid deficiency and result in several health problems, including macrocytic anemia, elevated plasma homocysteine, cardiovascular disease, birth defects, carcinogenesis, muscle weakness, and walking difficulty. However, the effect of folic acid deficiency on skeletal muscle development and its molecular mechanisms are unknown. We, therefore, investigated the effect of folic acid deficiency on myogenesis in skeletal muscle cells and found that folic acid deficiency induced proliferation inhibition and cell cycle breaking as well as cellular senescence in C2C12 myoblasts, implying that folic acid deficiency influences skeletal muscle development. Folic acid deficiency also inhibited differentiation of C2C12 myoblasts and induced deregulation of the cell cycle exit and many cell cycle regulatory genes. It inhibited expression of muscle-specific marker MyHC as well as myogenic regulatory factor (myogenin). Moreover, immunocytochemistry and Western blot analyses revealed that DNA damage was more increased in folic acid-deficient medium-treated differentiating C2C12 cells. Furthermore, we found that folic acid resupplementation reverses the effect on the cell cycle and senescence in folic acid-deficient C2C12 myoblasts but does not reverse the differentiation of C2C12 cells. Altogether, the study results suggest that folic acid is necessary for normal development of skeletal muscle cells. © 2017 Wiley Periodicals, Inc.

  9. Carbon-based hierarchical scaffolds for myoblast differentiation: Synergy between nano-functionalization and alignment.

    Science.gov (United States)

    Patel, Akhil; Mukundan, Shilpaa; Wang, Wenhu; Karumuri, Anil; Sant, Vinayak; Mukhopadhyay, Sharmila M; Sant, Shilpa

    2016-03-01

    While several scaffolds have been proposed for skeletal muscle regeneration, multiscale hierarchical scaffolds with the complexity of extracellular matrix (ECM) haven't been engineered successfully. By precise control over nano- and microscale features, comprehensive understanding of the effect of multiple factors on skeletal muscle regeneration can be derived. In this study, we engineered carbon-based scaffolds with hierarchical nano- and microscale architecture with controlled physico-chemical properties. More specifically, we built multiscale hierarchy by growing carbon nanotube (CNT) carpets on two types of scaffolds, namely, interconnected microporous carbon foams and aligned carbon fiber mats. Nanostructured CNT carpets offered fine control over nano-roughness and wettability facilitating myoblast adhesion, growth and differentiation into myocytes. However, microporous foam architecture failed to promote their fusion into multinucleated myotubes. On the other hand, aligned fibrous architecture stimulated formation of multinucleated myotubes. Most importantly, nanostructured CNT carpets interfaced with microscale aligned fibrous architecture significantly enhanced myocyte fusion into multinucleated mature myotubes highlighting synergy between nanoscale surface features and micro-/macroscale aligned fibrous architecture in the process of myogenesis. Due to limited regenerative potential of skeletal muscle, strategies stimulating regeneration of functional muscles are important. These strategies are aimed at promoting differentiation of progenitor cells (myoblasts) into multinucleated myotubes, a key initial step in functional muscle regeneration. Recent tissue engineering approaches utilize various scaffolds ranging from decellularized matrices to aligned biomaterial scaffolds. Although, majority of them have focused on nano- or microscale organization, a systematic approach to build the multiscale hierarchy into these scaffolds is lacking. Here, we engineered

  10. Propolis Ethanol Extract Stimulates Cytokine and Chemokine Production through NF-κB Activation in C2C12 Myoblasts

    Directory of Open Access Journals (Sweden)

    Kohei Washio

    2015-01-01

    Full Text Available Myoblast activation is a triggering event for muscle remodeling. We assessed the stimulatory effects of propolis, a beehive product, on myoblasts. After an 8 h treatment with 100 μg/mL of Brazilian propolis ethanol extract, expression of various chemokines, including CCL-2 and CCL-5, and cytokines, such as IL-6, increased. This propolis-induced cytokine production appears to depend on NF-κB activation, because the IKK inhibitor BMS-345541 repressed mRNA levels of CCL-2 by ~66%, CCL-5 by ~81%, and IL-6 by ~69% after propolis treatment. Supernatant from propolis-conditioned C2C12 cells upregulated RAW264 macrophage migration. The supernatant also stimulated RAW264 cells to produce angiogenic factors, including VEGF-A and MMP-12. Brazilian green propolis therefore causes myoblasts to secrete cytokines and chemokines, which might contribute to tissue remodeling of skeletal muscle.

  11. A novel in vitro model for studying quiescence and activation of primary isolated human myoblasts

    DEFF Research Database (Denmark)

    Sellathurai, Jeeva; Cheedipudi, Sirisha; Dhawan, Jyotsna

    2013-01-01

    term exponentially proliferating cultures normally used for in vitro studies. Human myoblasts cultured through many passages inevitably consist of a mixture of proliferating and non-proliferating cells, while cells activated from G0 are in a synchronously proliferating phase, and therefore may...... be a better model for in vivo proliferating satellite cells. Furthermore, the temporal propagation of proliferation in these synchronized cultures resembles the pattern seen in vivo during regeneration. We therefore present this culture model as a useful and novel condition for molecular analysis...

  12. Docosahexaenoyl ethanolamide improves glucose uptake and alters endocannabinoid system gene expression in proliferating and differentiating C2C12 myoblasts

    Directory of Open Access Journals (Sweden)

    Jeffrey eKim

    2014-03-01

    Full Text Available Skeletal muscle is a major storage site for glycogen and a focus for understanding insulin resistance and type-2-diabetes. New evidence indicates that overactivation of the peripheral endocannabinoid system (ECS in skeletal muscle diminishes insulin sensitivity. Specific n-6 and n-3 polyunsaturated fatty acids (PUFA are precursors for the biosynthesis of ligands that bind to and activate the cannabinoid receptors. The function of the ECS and action of PUFA in skeletal muscle glucose uptake was investigated in proliferating and differentiated C2C12 myoblasts treated with either 25µM of arachidonate (AA or docosahexaenoate (DHA, 25µM of EC [anandamide (AEA, 2-arachidonoylglycerol (2-AG, docosahexaenoylethanolamide (DHEA], 1µM of CB1 antagonist NESS0327, and CB2 antagonist AM630. Compared to the BSA vehicle control cell cultures in both proliferating and differentiated myoblasts those treated with DHEA, the EC derived from the n-3 PUFA DHA, had higher 24 h glucose uptake, while AEA and 2-AG, the EC derived from the n-6 PUFA AA, had lower basal glucose uptake. Adenylyl cyclase mRNA was higher in myoblasts treated with DHA in both proliferating and differentiated states while those treated with AEA or 2-AG were lower compared to the control cell cultures. Western blot and qPCR analysis showed higher expression of the cannabinoid receptors in differentiated myoblasts treated with DHA while the opposite was observed with AA. These findings indicate a compensatory effect of DHA and DHEA compared to AA-derived ligands on the ECS and associated ECS gene expression and higher glucose uptake in myoblasts.Key Words: endocannabinoid system •C2C12 myoblasts cannabinoid receptors glucose uptake gene expression DHEA • polyunsaturated fatty acids

  13. Laminin-Coated Poly(Methyl Methacrylate (PMMA Nanofiber Scaffold Facilitates the Enrichment of Skeletal Muscle Myoblast Population

    Directory of Open Access Journals (Sweden)

    Nor Kamalia Zahari

    2017-10-01

    Full Text Available Myoblasts, the contractile cells of skeletal muscle, have been invaluable for fundamental studies of muscle development and clinical applications for muscle loss. A major limitation to the myoblast-based therapeutic approach is contamination with non-contractile fibroblasts, which overgrow during cell expansion. To overcome these limitations, this study was carried out to establish a 3D culture environment using nanofiber scaffolds to enrich the myoblast population during construct formation. Poly(methyl methacrylate (PMMA nanofiber (PM scaffolds were fabricated using electrospinning techniques and coated with extracellular matrix (ECM proteins, such as collagen or laminin, in the presence or absence of genipin. A mixed population of myoblasts and fibroblasts was isolated from human skeletal muscle tissues and cultured on plain surfaces, as well as coated and non-coated PM scaffolds. PMMA can produce smooth fibers with an average diameter of 360 ± 50 nm. Adsorption of collagen and laminin on PM scaffolds is significantly enhanced in the presence of genipin, which introduces roughness to the nanofiber surface without affecting fiber diameter and mechanical properties. It was also demonstrated that laminin-coated PM scaffolds significantly enhance myoblast proliferation (0.0081 ± 0.0007 h−1 and migration (0.26 ± 0.04 μm/min, while collagen-coated PM scaffolds favors fibroblasts proliferation (0.0097 ± 0.0009 h−1 and migration (0.23 ± 0.03 μm/min. Consequently, the myoblast population was enriched on laminin-coated PM scaffolds throughout the culture process. Therefore, laminin coating of nanofiber scaffolds could be a potential scaffold for the development of a tissue-engineered muscle substitute.

  14. Laminin-Coated Poly(Methyl Methacrylate) (PMMA) Nanofiber Scaffold Facilitates the Enrichment of Skeletal Muscle Myoblast Population.

    Science.gov (United States)

    Zahari, Nor Kamalia; Idrus, Ruszymah Binti Haji; Chowdhury, Shiplu Roy

    2017-10-30

    Myoblasts, the contractile cells of skeletal muscle, have been invaluable for fundamental studies of muscle development and clinical applications for muscle loss. A major limitation to the myoblast-based therapeutic approach is contamination with non-contractile fibroblasts, which overgrow during cell expansion. To overcome these limitations, this study was carried out to establish a 3D culture environment using nanofiber scaffolds to enrich the myoblast population during construct formation. Poly(methyl methacrylate) (PMMA) nanofiber (PM) scaffolds were fabricated using electrospinning techniques and coated with extracellular matrix (ECM) proteins, such as collagen or laminin, in the presence or absence of genipin. A mixed population of myoblasts and fibroblasts was isolated from human skeletal muscle tissues and cultured on plain surfaces, as well as coated and non-coated PM scaffolds. PMMA can produce smooth fibers with an average diameter of 360 ± 50 nm. Adsorption of collagen and laminin on PM scaffolds is significantly enhanced in the presence of genipin, which introduces roughness to the nanofiber surface without affecting fiber diameter and mechanical properties. It was also demonstrated that laminin-coated PM scaffolds significantly enhance myoblast proliferation (0.0081 ± 0.0007 h-1) and migration (0.26 ± 0.04 μm/min), while collagen-coated PM scaffolds favors fibroblasts proliferation (0.0097 ± 0.0009 h-1) and migration (0.23 ± 0.03 μm/min). Consequently, the myoblast population was enriched on laminin-coated PM scaffolds throughout the culture process. Therefore, laminin coating of nanofiber scaffolds could be a potential scaffold for the development of a tissue-engineered muscle substitute.

  15. Rats

    Directory of Open Access Journals (Sweden)

    Alexey Kondrashov

    2012-01-01

    Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

  16. Fusion from myoblasts to myotubes is dependent on the rolling stone gene (rost) of Drosophila.

    Science.gov (United States)

    Paululat, A; Burchard, S; Renkawitz-Pohl, R

    1995-08-01

    The development and differentiation of the body wall musculature in Drosophila are accompanied by changes in gene expression and cellular architecture. We isolated a Drosophila gene, termed rolling stone (rost), which, when mutated, specifically blocks the fusion of mononucleated cells to myotubes in the body wall musculature. beta 3 tubulin, which is an early marker for the onset of mesoderm differentiation, is still expressed in these cells. Gastrulation and mesoderm formation, as well as the development of the epidermis and of the central and peripheral nervous systems, appear quite normal in homozygous rolling stone embryos. Embryonic development stops shortly before hatching in a P-element-induced mutant, as well as in 16 EMS-induced alleles. In mutant embryos, other mesodermal derivatives such as the visceral mesoderm and the dorsal vessel, develop fairly normally and defects are restricted to the body wall musculature. Myoblasts remain as single mononucleated cells, which express muscle myosin, showing that the developmental program of gene expression proceeds. These myoblasts occur at positions corresponding to the locations of dorsal, ventral and pleural muscles, showing that the gene rolling stone is involved in cell fusion, a process that is independent of cell migration in these mutants. This genetic analysis has set the stage for a molecular analysis to clarify where the rolling stone action is manifested in the fusion process and thus gives insight into the complex regulating network controlling the differentiation of the body wall musculature.

  17. Production of IL-6 by human myoblasts stimulated with Abeta: relevance in the pathogenesis of IBM.

    Science.gov (United States)

    Baron, P; Galimberti, D; Meda, L; Scarpini, E; Conti, G; Cogiamanian, F; Scarlato, G

    2001-11-13

    To determine whether amyloid-beta protein (Abeta) can induce the production of proinflammatory cytokines by cultured normal muscle cells. Sporadic inclusion body myositis (IBM) is characterized by the presence of rimmed vacuoles and fibrillary inclusions of Abeta in muscle fibers, and often inflammatory cells. Endomysial expression of proinflammatory molecules has suggested an ongoing immune process, but the site of sensitization and the mechanisms that trigger an inflammatory reaction is unknown. The authors used Northern blot analysis and specific immunoassays to study the expression and secretion in cell-free supernatants of tumor necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) by purified human myoblasts and C2C12 mouse skeletal muscle cells incubated with Abeta[1-42] or Abeta[25-35] peptides. Nonstimulated muscle cells produced detectable IL-6, whereas secretion of IL-1beta and TNFalpha was absent. Incubation with Abeta peptides increased IL-6 production, whereas TNFalpha and IL-1beta levels remained undetectable. Northern blot analysis of Abeta-stimulated human myoblasts revealed an increase in IL-6 mRNA expression. Cultured muscle cells increase the constitutive production of IL-6 in response to local deposition of Abeta in sporadic IBM. IL-6 could be a CD8(+) proliferation and differentiation agent, an autocrine proteolysis-inducing factor of damaged myotubes, and a proliferation-stimulating agent for satellite cells to replace the destroyed myofibers in IBM.

  18. α-Syntrophin stabilizes catalase to reduce endogenous reactive oxygen species levels during myoblast differentiation.

    Science.gov (United States)

    Moon, Jae Yun; Choi, Su Jin; Heo, Cheol Ho; Kim, Hwan Myung; Kim, Hye Sun

    2017-07-01

    α-Syntrophin is a component of the dystrophin-glycoprotein complex that interacts with various intracellular signaling proteins in muscle cells. The α-syntrophin knock-down C2 cell line (SNKD), established by infecting lentivirus particles with α-syntrophin shRNA, is characterized by a defect in terminal differentiation and increase in cell death. Since myoblast differentiation is accompanied by intensive mitochondrial biogenesis, the generation of intracellular reactive oxygen species (ROS) is also increased during myogenesis. Two-photon microscopy imaging showed that excessive intracellular ROS accumulated during the differentiation of SNKD cells as compared with control cells. The formation of 4-hydroxynonenal adduct, a byproduct of lipid peroxidation during oxidative stress, significantly increased in differentiated SNKD myotubes and was dramatically reduced by epigallocatechin-3-gallate, a well-known ROS scavenger. Among antioxidant enzymes, catalase was significantly decreased during differentiation of SNKD cells without changes at the mRNA level. Of interest was the finding that the degradation of catalase was rescued by MG132, a proteasome inhibitor, in the SNKD cells. This study demonstrates a novel function of α-syntrophin. This protein plays an important role in the regulation of oxidative stress from endogenously generated ROS during myoblast differentiation by modulating the protein stability of catalase. © 2017 Federation of European Biochemical Societies.

  19. Insulin upregulates GRIM-19 and protects cardiac mitochondrial morphology in type 1 diabetic rats partly through PI3K/AKT signaling pathway.

    Science.gov (United States)

    Li, Yong-Guang; Dong, Zhi-Feng; Chen, Kan-Kai; He, Ya-Ping; Dai, Xiao-Yan; Li, Shuai; Li, Jing-Bo; Zhu, Wei; Wei, Meng

    2017-11-04

    Insulin is involved in the development of diabetic heart disease and is important in the activities of mitochondrial complex I. However, the effect of insulin on cardiac mitochondrial nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) 1 subunit of retinoic-interferon-induced mortality 19 (GRIM-19) has not been characterized. The aim of this study was to investigate the effect of insulin on the mitochondrial GRIM-19 in the hearts of rats with streptozotocin (STZ)-induced type 1 diabetes. Protein changes of GRIM-19 were evaluated by western blotting and reverse transcription-quantitative polymerase chain reaction. Furthermore, the effects of insulin on mitochondrial complex I were detected in HeLa cells and H9C2 cardiac myocytes. During the development of diabetic heart disease, the cardiac function did not change within the 8 weeks, but the mitochondrial morphology was altered. The hearts from the rats with STZ-induced diabetes exhibited reduced expression of GRIM-19. Prior to the overt cardiac dilatation, mitochondrial alterations were already present. Following subcutaneous insulin injection, it was demonstrated that GRIM-19 protein was altered, as well as the mitochondrial morphology. The phosphoinositide 3-kinase inhibitor LY294002 had an effect on insulin signaling in H9C2 cardiacmyocytes, and decreased the level of GRIM-19 by half compared with that in the insulin group. The results indicate that insulin is essential for the control of cardiac mitochondrial morphology and the GRIM-19 expression partly via PI3K/AKT signaling pathways. Copyright © 2017. Published by Elsevier Inc.

  20. Mechanical stimuli activation of calpain is required for myoblast differentiation and occurs via an ERK/MAP kinase signaling pathway

    DEFF Research Database (Denmark)

    Grossi, Alberto; Karlsson, Anders H; Lawson, Moira Ann

    tissues. Stimulation due to stretch- or load-induced signaling is now beginning to be understood as a factor which affects various signal transduction pathways, gene sequences and protein synthesis. Evidence of the involvement of mitogen-activated protein kinase (MAPK) cascade activation in myoblast...

  1. Mesenchymal Stromal Cell Secreted Sphingosine 1-Phosphate (S1P) Exerts a Stimulatory Effect on Skeletal Myoblast Proliferation

    Science.gov (United States)

    Tani, Alessia; Anderloni, Giulia; Pierucci, Federica; Matteini, Francesca; Chellini, Flaminia; Zecchi Orlandini, Sandra; Meacci, Elisabetta

    2014-01-01

    Bone-marrow-derived mesenchymal stromal cells (MSCs) have the potential to significantly contribute to skeletal muscle healing through the secretion of paracrine factors that support proliferation and enhance participation of the endogenous muscle stem cells in the process of repair/regeneration. However, MSC-derived trophic molecules have been poorly characterized. The aim of this study was to investigate paracrine signaling effects of MSCs on skeletal myoblasts. It was found, using a biochemical and morphological approach that sphingosine 1-phosphate (S1P), a natural bioactive lipid exerting a broad range of muscle cell responses, is secreted by MSCs and represents an important factor by which these cells exert their stimulatory effects on C2C12 myoblast and satellite cell proliferation. Indeed, exposure to conditioned medium obtained from MSCs cultured in the presence of the selective sphingosine kinase inhibitor (iSK), blocked increased cell proliferation caused by the conditioned medium from untreated MSCs, and the addition of exogenous S1P in the conditioned medium from MSCs pre-treated with iSK further increased myoblast proliferation. Finally, we also demonstrated that the myoblast response to MSC-secreted vascular endothelial growth factor (VEGF) involves the release of S1P from C2C12 cells. Our data may have important implications in the optimization of cell-based strategies to promote skeletal muscle regeneration. PMID:25264785

  2. Low Oxygen Tension Enhances Expression of Myogenic Genes When Human Myoblasts Are Activated from G0 Arrest

    DEFF Research Database (Denmark)

    Sellathurai, Jeeva; Nielsen, Joachim; Hejbøl, Eva Kildall

    2016-01-01

    and Wnt signaling pathways were also up regulated in low oxygen tension. The differences in gene expression were most pronounced at day one after activation from G0-arrest, thus the initial activation of myoblasts seemed most sensitive to changes in oxygen tension. Protein expression of HES1 and β...

  3. Action of lovastatin, simvastatin, and pravastatin on sterol synthesis and their antiproliferative effect in cultured myoblasts from human striated muscle

    NARCIS (Netherlands)

    Vliet, A.K. van; Nègre-Arrariou, P.; Thiel, G.C.F. van; Bolhuis, P.A.; Cohen, L.H.

    1996-01-01

    Lovastatin, simvastatin, and pravastatin are fairly strong inhibitors of sterol synthesis in human myoblasts in culture. Lovastatin and simvastatin have IC50 values of 19 ± 6 nM and 4.0 ± 2.3 nM, respectively. Pravastatin is a weaker inhibitor of sterol synthesis (IC50 value of 110 ± 38 nM). Through

  4. Biodistribution studies of {sup 99m}Tc-labeled myoblasts in a murine model of muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, F.R. E-mail: colombof@policlinico.mi.it; Torrente, Y.; Casati, R.; Benti, R.; Corti, S.; Salani, S.; D' Angelo, M.G.; DeLiso, A.; Scarlato, G.; Bresolin, N.; Gerundini, P

    2001-11-01

    The purpose of this study was twofold: first, to evaluate the myoblast labeling of various {sup 99m}Tc complexes and to select the complex that best accomplishes this labeling, and second to evaluate the biodistribution of myoblasts labeled with this complex using mice with MDX muscular dystrophy (the murine homologue of Duchenne's muscular dystrophy). The following ligands were used to prepare the corresponding {sup 99m}Tc complexes: hexakis-methoxy-isobutyl-isonitrile (MIBI), bis(2-ethoxyethyl)diphosphinoethane (Tf), (RR,SS)-4,8-diaza-3,6,6,9-tetramethyl-undecane-2,10-dione-bisoxime (HM-PAO), bis(N-ethyl)dithiocarbamate (NEt), and bis(N-ethoxy, N-ethyl)dithiocarbamate (NOEt). One million murine myoblasts were incubated for 30-60 minutes with 5 mCi of each of the 99mTc complexes prepared from the above ligands. Viability was assessed by microscopic counting after trypan blue staining, and the radioactivity absorbed in the cells was measured after centrifugation. The compound with the highest uptake in cellular pellets was [{sup 99m}Tc]N-NOEt. The biodistribution of myoblasts labeled with this complex was evaluated after intraaortic injection in dystrophic mice. Such an approach has the potential of effecting widespread gene transfer through the bloodstream to muscles lacking dystrophin.

  5. Adipose Tissue-Derived Stem Cell Secreted IGF-1 Protects Myoblasts from the Negative Effect of Myostatin

    Directory of Open Access Journals (Sweden)

    Sebastian Gehmert

    2014-01-01

    Full Text Available Myostatin, a TGF-β family member, is associated with inhibition of muscle growth and differentiation and might interact with the IGF-1 signaling pathway. Since IGF-1 is secreted at a bioactive level by adipose tissue-derived mesenchymal stem cells (ASCs, these cells (ASCs provide a therapeutic option for Duchenne Muscular Dystrophy (DMD. But the protective effect of stem cell secreted IGF-1 on myoblast under high level of myostatin remains unclear. In the present study murine myoblasts were exposed to myostatin under presence of ASCs conditioned medium and investigated for proliferation and apoptosis. The protective effect of IGF-1 was further examined by using IGF-1 neutralizing and receptor antibodies as well as gene silencing RNAi technology. MyoD expression was detected to identify impact of IGF-1 on myoblasts differentiation when exposed to myostatin. IGF-1 was accountable for 43.6% of the antiapoptotic impact and 48.8% for the proliferative effect of ASCs conditioned medium. Furthermore, IGF-1 restored mRNA and protein MyoD expression of myoblasts under risk. Beside fusion and transdifferentiation the beneficial effect of ASCs is mediated by paracrine secreted cytokines, particularly IGF-1. The present study underlines the potential of ASCs as a therapeutic option for Duchenne muscular dystrophy and other dystrophic muscle diseases.

  6. Actin-associated protein palladin is required for migration behavior and differentiation potential of C2C12 myoblast cells

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ngoc Uyen Nhi; Liang, Vincent Roderick; Wang, Hao-Ven, E-mail: hvwang@mail.ncku.edu.tw

    2014-09-26

    Highlights: • Palladin is involved in myogenesis in vitro. • Palladin knockdown by siRNA increases myoblast proliferation, viability and differentiation. • Palladin knockdown decreases C2C12 myoblast migration ability. - Abstract: The actin-associated protein palladin has been shown to be involved in differentiation processes in non-muscle tissues. However, but its function in skeletal muscle has rarely been studied. Palladin plays important roles in the regulation of diverse actin-related signaling in a number of cell types. Since intact actin-cytoskeletal remodeling is necessary for myogenesis, in the present study, we pursue to investigate the role of actin-associated palladin in skeletal muscle differentiation. Palladin in C2C12 myoblasts is knocked-down using specific small interfering RNA (siRNA). The results show that down-regulation of palladin decreased migratory activity of mouse skeletal muscle C2C12 myoblasts. Furthermore, the depletion of palladin enhances C2C12 vitality and proliferation. Of note, the loss of palladin promotes C2C12 to express the myosin heavy chain, suggesting that palladin has a role in the modulation of C2C12 differentiation. It is thus proposed that palladin is required for normal C2C12 myogenesis in vitro.

  7. Myogenesis in the sea urchin embryo: the molecular fingerprint of the myoblast precursors

    Science.gov (United States)

    2013-01-01

    Background In sea urchin larvae the circumesophageal fibers form a prominent muscle system of mesodermal origin. Although the morphology and later development of this muscle system has been well-described, little is known about the molecular signature of these cells or their precise origin in the early embryo. As an invertebrate deuterostome that is more closely related to the vertebrates than other commonly used model systems in myogenesis, the sea urchin fills an important phylogenetic gap and provides a unique perspective on the evolution of muscle cell development. Results Here, we present a comprehensive description of the development of the sea urchin larval circumesophageal muscle lineage beginning with its mesodermal origin using high-resolution localization of the expression of several myogenic transcriptional regulators and differentiation genes. A few myoblasts are bilaterally distributed at the oral vegetal side of the tip of the archenteron and first appear at the late gastrula stage. The expression of the differentiation genes Myosin Heavy Chain, Tropomyosin I and II, as well as the regulatory genes MyoD2, FoxF, FoxC, FoxL1, Myocardin, Twist, and Tbx6 uniquely identify these cells. Interestingly, evolutionarily conserved myogenic factors such as Mef2, MyoR and Six1/2 are not expressed in sea urchin myoblasts but are found in other mesodermal domains of the tip of the archenteron. The regulatory states of these domains were characterized in detail. Moreover, using a combinatorial analysis of gene expression we followed the development of the FoxF/FoxC positive cells from the onset of expression to the end of gastrulation. Our data allowed us to build a complete map of the Non-Skeletogenic Mesoderm at the very early gastrula stage, in which specific molecular signatures identify the precursors of different cell types. Among them, a small group of cells within the FoxY domain, which also express FoxC and SoxE, have been identified as plausible myoblast

  8. Myogenesis in the sea urchin embryo: the molecular fingerprint of the myoblast precursors.

    Science.gov (United States)

    Andrikou, Carmen; Iovene, Edmondo; Rizzo, Francesca; Oliveri, Paola; Arnone, Maria Ina

    2013-12-02

    In sea urchin larvae the circumesophageal fibers form a prominent muscle system of mesodermal origin. Although the morphology and later development of this muscle system has been well-described, little is known about the molecular signature of these cells or their precise origin in the early embryo. As an invertebrate deuterostome that is more closely related to the vertebrates than other commonly used model systems in myogenesis, the sea urchin fills an important phylogenetic gap and provides a unique perspective on the evolution of muscle cell development. Here, we present a comprehensive description of the development of the sea urchin larval circumesophageal muscle lineage beginning with its mesodermal origin using high-resolution localization of the expression of several myogenic transcriptional regulators and differentiation genes. A few myoblasts are bilaterally distributed at the oral vegetal side of the tip of the archenteron and first appear at the late gastrula stage. The expression of the differentiation genes Myosin Heavy Chain, Tropomyosin I and II, as well as the regulatory genes MyoD2, FoxF, FoxC, FoxL1, Myocardin, Twist, and Tbx6 uniquely identify these cells. Interestingly, evolutionarily conserved myogenic factors such as Mef2, MyoR and Six1/2 are not expressed in sea urchin myoblasts but are found in other mesodermal domains of the tip of the archenteron. The regulatory states of these domains were characterized in detail. Moreover, using a combinatorial analysis of gene expression we followed the development of the FoxF/FoxC positive cells from the onset of expression to the end of gastrulation. Our data allowed us to build a complete map of the Non-Skeletogenic Mesoderm at the very early gastrula stage, in which specific molecular signatures identify the precursors of different cell types. Among them, a small group of cells within the FoxY domain, which also express FoxC and SoxE, have been identified as plausible myoblast precursors. Together

  9. Human myotubes from myoblast cultures undergoing senescence exhibit defects in glucose and lipid metabolism

    DEFF Research Database (Denmark)

    Nehlin, Jan O; Just, Marlene; Rustan, Arild C

    2011-01-01

    Adult stem cells are known to have a finite replication potential. Muscle biopsy-derived human satellite cells (SCs) were grown at different passages and differentiated to human myotubes in culture to analyze the functional state of various carbohydrate and lipid metabolic pathways...... number and could be explained by reduced incorporation into diacyl- and triacylglycerols. The levels of long-chain acyl-CoA esters decreased with increased passage number. Late-passage, non-proliferating, myoblast cultures showed strong senescence-associated β-galactosidase activity indicating...... that the observed metabolic defects accompany the induction of a senescent state. The main function of SCs is regeneration and skeletal muscle-build up. Thus, the metabolic defects observed during aging of SC-derived myotubes could have a role in sarcopenia, the gradual age-related loss of muscle mass and strength....

  10. Effect of oxygen tension on bioenergetics and proteostasis in young and old myoblast precursor cells

    Directory of Open Access Journals (Sweden)

    M. Konigsberg

    2013-01-01

    Full Text Available In the majority of studies using primary cultures of myoblasts, the cells are maintained at ambient oxygen tension (21% O2, despite the fact that physiological O2 at the tissue level in vivo is much lower (~1–5% O2. We hypothesized that the cellular response in presence of high oxygen concentration might be particularly important in studies comparing energetic function or oxidative stress in cells isolated from young versus old animals. To test this, we asked whether oxygen tension plays a role in mitochondrial bioenergetics (oxygen consumption, glycolysis and fatty acid oxidation or oxidative damage to proteins (protein disulfides, carbonyls and aggregates in myoblast precursor cells (MPCs isolated from young (3–4 m and old (29–30 m C57BL/6 mice. MPCs were grown under physiological (3% or ambient (21% O2 for two weeks prior to exposure to an acute oxidative insult (H2O2. Our results show significantly higher basal mitochondrial respiration in young versus old MPCs, an increase in basal respiration in young MPCs maintained at 3% O2 compared to cells maintained at 21% O2, and a shift toward glycolytic metabolism in old MPCs grown at 21% O2. H2O2 treatment significantly reduced respiration in old MPCs grown at 3% O2 but did not further repress respiration at 21% O2 in old MPCs. Oxidative damage to protein was higher in cells maintained at 21% O2 and increased in response to H2O2 in old MPCs. These data underscore the importance of understanding the effect of ambient oxygen tension in cell culture studies, in particular studies measuring oxidative damage and mitochondrial function.

  11. Binding of the chemokine CXCL12α to its natural extracellular matrix ligand heparan sulfate enables myoblast adhesion and facilitates cell motility.

    Science.gov (United States)

    Thakar, Dhruv; Dalonneau, Fabien; Migliorini, Elisa; Lortat-Jacob, Hugues; Boturyn, Didier; Albiges-Rizo, Corinne; Coche-Guerente, Liliane; Picart, Catherine; Richter, Ralf P

    2017-04-01

    The chemokine CXCL12α is a potent chemoattractant that guides the migration of muscle precursor cells (myoblasts) during myogenesis and muscle regeneration. To study how the molecular presentation of chemokines influences myoblast adhesion and motility, we designed multifunctional biomimetic surfaces as a tuneable signalling platform that enabled the response of myoblasts to selected extracellular cues to be studied in a well-defined environment. Using this platform, we demonstrate that CXCL12α, when presented by its natural extracellular matrix ligand heparan sulfate (HS), enables the adhesion and spreading of myoblasts and facilitates their active migration. In contrast, myoblasts also adhered and spread on CXCL12α that was quasi-irreversibly surface-bound in the absence of HS, but were essentially immotile. Moreover, co-presentation of the cyclic RGD peptide as integrin ligand along with HS-bound CXCL12α led to enhanced spreading and motility, in a way that indicates cooperation between CXCR4 (the CXCL12α receptor) and integrins (the RGD receptors). Our findings reveal the critical role of HS in CXCL12α induced myoblast adhesion and migration. The biomimetic surfaces developed here hold promise for mechanistic studies of cellular responses to different presentations of biomolecules. They may be broadly applicable for dissecting the signalling pathways underlying receptor cross-talks, and thus may guide the development of novel biomaterials that promote highly specific cellular responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Uniaxial cyclic strain of human adipose–derived mesenchymal stem cells and C2C12 myoblasts in coculture

    Directory of Open Access Journals (Sweden)

    James M Dugan

    2014-03-01

    Full Text Available Tissue engineering skeletal muscle in vitro is of great importance for the production of tissue-like constructs for treating tissue loss due to traumatic injury or surgery. However, it is essential to find new sources of cells for muscle engineering as efficient in vitro expansion and culture of primary myoblasts are problematic. Mesenchymal stem cells may be a promising source of myogenic progenitor cells and may be harvested in large numbers from adipose tissue. As skeletal muscle is a mechanically dynamic tissue, we have investigated the effect of cyclic mechanical strain on the myogenic differentiation of a coculture system of murine C2C12 myoblasts and human adipose–derived mesenchymal stem cells. Fusion of mesenchymal stem cells with nascent myotubes and expression of human sarcomeric proteins was observed, indicating the potential for myogenic differentiation of human mesenchymal stem cells. Cyclic mechanical strain did not affect the fusion of mesenchymal stem cells, but maturation of myotubes was perturbed.

  13. Options for tracking GFP-Labeled transplanted myoblasts using in vivo fluorescence imaging: implications for tracking stem cell fate.

    Science.gov (United States)

    Yang, Zhong; Wang, Yaming; Li, Yanan; Liu, Qiang; Zeng, Qing; Xu, Xiaoyin

    2014-06-12

    Green fluorescent protein (GFP) is a useful biomarker, widely used in biomedical research to track stem cells after transplantation and/or to assess therapeutic transgene expression. However, both GFP and therapeutic gene products themselves may be immunogenic to the recipient. The main aim of this study was to use animal models to evaluate potential impact of GFP on the cell engraftment and to optimize tracking strategies prior to transplantation. By using a fluorescent imaging (FLI) system, we investigated the dynamic cell behavior of GFP-transduced myoblasts in tibialis anterior (TA) muscles of immunocompetent mdx mice and immuno-compromised nude mice over a period of three months. The results suggested an apparent underlying host immunorejection in the mdx mice. Dystrophin immunostaining showed that the engraftment of wild type myoblasts was much more effective than that of the GFP-labeled counterparts in the mdx mice, further confirming an antigen role of GFP in this process. We tracked the GFP-transduced myoblasts in C57BL/6 mice and found GFP to be minimally immunogenic in these animals, as indicated by the GFP signal maintaining a much stronger level than that found in mdx and BALB/c mice at parallel time points. We also compared the in vivo cell behavior differences between myoblasts from virally GFP-transduced and GFP transgenic mice. The latter displayed much better engraftment, as determined both biomaging and histological observations. Our results not only demonstrated the immunogenicity of GFP in immunocompetent mice, but determined the optimized conditions for GFP-based in vivo stem cells tracking, that can potentially be extrapolated to human biomedical research.

  14. The Mesodermal Expression of rolling stone (rost) Is Essential for Myoblast Fusion in Drosophila and Encodes a Potential Transmembrane Protein

    OpenAIRE

    Paululat, Achim; Goubeaud, Anette; Damm, Christine; Knirr, Stefan; Burchard, Susanne; Renkawitz-Pohl, Renate

    1997-01-01

    In homozygous rolling stone embryos, the fusion of myoblasts to syncytial myotubes is diminished. Nevertheless, the visceral mesoderm, the heart mesoderm, and few somatic muscles are properly formed. Thus, we postulate a central role of rolling stone for the fusion process within the somatic mesoderm. We have cloned the rolling stone gene, and the deduced protein sequence is in accordance with a transmembrane protein, which agrees with the enrichment of Rost in the membrane fraction of Drosop...

  15. Six1 induces protein synthesis signaling expression in duck myoblasts mainly via up-regulation of mTOR

    Directory of Open Access Journals (Sweden)

    Haohan Wang

    2016-03-01

    Full Text Available Abstract As a critical transcription factor, Six1 plays an important role in the regulation of myogenesis and muscle development. However, little is known about its regulatory mechanism associated with muscular protein synthesis. The objective of this study was to investigate the effects of overexpression ofSix1 on the expression of key protein metabolism-related genes in duck myoblasts. Through an experimental model where duck myoblasts were transfected with a pEGFP-duSix1 construct, we found that overexpression of duckSix1 could enhance cell proliferation activity and increase mRNA expression levels of key genes involved in the PI3K/Akt/mTOR signaling pathway, while the expression of FOXO1, MuRF1and MAFbx was not significantly altered, indicating thatSix1 could promote protein synthesis in myoblasts through up-regulating the expression of several related genes. Additionally, in duck myoblasts treated with LY294002 and rapamycin, the specific inhibitors ofPI3K and mTOR, respectively, the overexpression of Six1 could significantly ameliorate inhibitive effects of these inhibitors on protein synthesis. Especially, the mRNA expression levels of mTOR and S6K1 were observed to undergo a visible change, and a significant increase in protein expression of S6K1 was seen. These data suggested that Six1plays an important role in protein synthesis, which may be mainly due to activation of the mTOR signaling pathway.

  16. Fatty acids increase glucose uptake and metabolism in C2C12 myoblasts stably transfected with human lipoprotein lipase.

    Science.gov (United States)

    Capell, Warren H; Schlaepfer, Isabel R; Wolfe, Pamela; Watson, Peter A; Bessesen, Daniel H; Pagliassotti, Michael J; Eckel, Robert H

    2010-10-01

    Cellular effects of FFA might differ from those of lipoprotein triglyceride (TG)-derived fatty acids (TGFA). The aim of the current study was to examine the relationship between lipoprotein lipase (LPL) expression, TGFA, or FFA availability and glucose metabolism in the absence of insulin in C2C12 myoblasts. Control myoblasts or myoblasts stably transfected with human lipoprotein lipase (C2/LPL; 15-fold greater LPL activity) were incubated for 12 h in fetal bovine serum-free medium in the absence or presence of Intralipid-20. Intracellular retention of labeled medium glucose was assessed in a subset of experiments. In the presence of Intralipid, medium glucose disappearance was increased in C2/LPL cells but not in control cells. In both cell types, glucose label retention in cellular TG was increased in the presence of Intralipid; incubation with albumin-bound oleate produced similar results. In the presence of Intralipid, the LPL hydrolytic inhibitor tetrahydrolipstatin blocked excess glucose retention in cellular TG but did not significantly decrease glucose disappearance in C2/LPL cells. Changes in glucose transport or hexokinase II did not explain the altered glucose disappearance in C2/LPL cells. Our results suggest that LPL overexpression in these cells leads to chronic metabolic adaptations that alter glucose uptake and retention.

  17. The mesodermal expression of rolling stone (rost) is essential for myoblast fusion in Drosophila and encodes a potential transmembrane protein.

    Science.gov (United States)

    Paululat, A; Goubeaud, A; Damm, C; Knirr, S; Burchard, S; Renkawitz-Pohl, R

    1997-07-28

    In homozygous rolling stone embryos, the fusion of myoblasts to syncytial myotubes is diminished. Nevertheless, the visceral mesoderm, the heart mesoderm, and few somatic muscles are properly formed. Thus, we postulate a central role of rolling stone for the fusion process within the somatic mesoderm. We have cloned the rolling stone gene, and the deduced protein sequence is in accordance with a transmembrane protein, which agrees with the enrichment of Rost in the membrane fraction of Drosophila embryos. No homologous genes have been described so far. rolling stone is expressed in the embryonic nervous system and cells of the somatic mesoderm, most notable in muscle founder cells. To elucidate the function of rolling stone for myoblast fusion, we applied a knock-out strategy. The expression of an antisense rolling stone transcript specifically within the mesoderm of wild-type embryos results in fusion defects of myoblasts, proving that the rolling stone expression in the mesoderm is responsible for the rolling stone phenotype. We suggest that rolling stone is a member of a group of genes that are necessary for the fusion process during myogenesis.

  18. siRNA delivery into cultured primary human myoblasts--optimization of electroporation parameters and theoretical analysis.

    Science.gov (United States)

    Lojk, Jasna; Mis, Katarina; Pirkmajer, Sergej; Pavlin, Mojca

    2015-12-01

    Introduction of genetic material into muscle tissue has been extensively researched, including isolation and in vitro expansion of primary myoblasts as a potential source of cells for skeletal and heart muscle tissue engineering applications. In this study, we optimized the electroporation protocol for introduction of short interfering ribonucleic acid (siRNA) against messenger RNA for Hypoxia Inducible Factor 1α (HIF-1α) into cultured primary human myoblasts. We established optimal pulsing protocol for siRNA electro transfection, and theoretically analyzed the effect of electric field and pulse duration on silencing efficiency and electrophoretic displacement of siRNA. Silencing of HIF-1α was determined with quantitative polymerase chain reaction and Western Blot. The most efficient silencing (71% knockdown) was achieved with 8 × 2 ms pulses, E = 0.6 kV/cm. Viability was determined immediately, 1 h and 48 h after electroporation. In general, there was a trade-off between efficient silencing and preserved viability. Electric field and pulse duration are crucial parameters for silencing, since both increase membrane permeabilization and electrophoretic transfer of siRNA. Short-term viability showed immediate toxicity of pulses due to membrane damage, while indirect effects on cell proliferation were observed after 48 h. Presented results are important for faster optimization of electroporation parameters for ex vivo electrotransfer of short RNA molecules into primary human myoblasts. © 2015 Wiley Periodicals, Inc.

  19. Identification of valid reference genes during the differentiation of human myoblasts

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    Hörmann Karl

    2009-07-01

    Full Text Available Abstract Background Analysis of RNA expression using real-time PCR (qRT-PCR traditionally includes reference genes (RG as an internal control. This practice is being questioned as it becomes increasingly clear that RG may vary considerably under certain experimental conditions. Thus, the validity of a particular RG must be determined for each experimental setting. We used qRT-PCR to measure the levels of six RG, which have been reported in the literature to be invariant. The RG were analyzed in human myoblast cultures under differentiation conditions. We examined the expression by qRT-PCR of mRNA encoding Beta-actin (ACTB, Beta-2-microglobulin (B2M, glyceraldehyde-3-phosphate dehydrogenase (GAPDH, peptidylprolyl isomerase A (PPIA, TATA box binding protein (TBP and ribosomal protein, large, P0 (RPLPO. The mRNA expression of the following genes of interest (GOI were analyzed: skeletal muscle alpha 1 actin (ACTA1, myogenin/myogenic factor 4 (MYOG, embryonic skeletal muscle myosin heavy chain 3 (MYH3 and the activity of creatine phosphokinase (CK. The geNorm, NormFinder and BestKeeper software programs were used to ascertain the most suitable RG to normalize the RNA input. Results Using the geNorm program, RPLPO and TBP were found to be the most stable genes, additionally a suitable normalization factor (NF was calculated. The NormFinder software showed that RPLPO was the most stable, whereas TBP ranked second. BestKeeper program also revealed that RPLPO and TBP as stable genes, but PPIA was the most stable reference gene, whereas GAPDH and ACTB were the worst ranked. Conclusion RNA expression analyses including three independent softwares revealed that RPLPO, TBP as reference genes or NF calculated by geNorm software, are suitable to normalize the mRNA expression in myoblast after culture under differentiation conditions. Significant correlations can be identified between the differentiations markers ACTA1, MYOG, MYH3 and creatine phosphokinase (CK

  20. The Tocotrienol-Rich Fraction Is Superior to Tocopherol in Promoting Myogenic Differentiation in the Prevention of Replicative Senescence of Myoblasts.

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    Shy Cian Khor

    Full Text Available Aging results in a loss of muscle mass and strength. Myoblasts play an important role in maintaining muscle mass through regenerative processes, which are impaired during aging. Vitamin E potentially ameliorates age-related phenotypes. Hence, this study aimed to determine the effects of the tocotrienol-rich fraction (TRF and α-tocopherol (ATF in protecting myoblasts from replicative senescence and promoting myogenic differentiation. Primary human myoblasts were cultured into young and senescent stages and were then treated with TRF or ATF for 24 h, followed by an analysis of cell proliferation, senescence biomarkers, cellular morphology and differentiation. Our data showed that replicative senescence impaired the normal regenerative processes of myoblasts, resulting in changes in cellular morphology, cell proliferation, senescence-associated β-galactosidase (SA-β-gal expression, myogenic differentiation and myogenic regulatory factors (MRFs expression. Treatment with both TRF and ATF was beneficial to senescent myoblasts in reclaiming the morphology of young cells, improved cell viability and decreased SA-β-gal expression. However, only TRF treatment increased BrdU incorporation in senescent myoblasts, as well as promoted myogenic differentiation through the modulation of MRFs at the mRNA and protein levels. MYOD1 and MYOG gene expression and myogenin protein expression were modulated in the early phases of myogenic differentiation. In conclusion, the tocotrienol-rich fraction is superior to α-tocopherol in ameliorating replicative senescence-related aberration and promoting differentiation via modulation of MRFs expression, indicating vitamin E potential in modulating replicative senescence of myoblasts.

  1. Disruption of myoblast alignment by highly motile rhabdomyosarcoma cell in tissue structure.

    Science.gov (United States)

    Li, Menglu; Nagamori, Eiji; Kino-Oka, Masahiro

    2017-02-01

    Rhabdomyosarcoma (RMS) is a highly malignant tumor type of skeletal muscle origin, hallmarked by local invasion. Interaction between invasive tumor cells and normal cells plays a major role in tumor invasion and metastasis. Culturing tumor cells in a three-dimensional (3D) model can translate tumor malignancy relevant cell-cell interaction. To mimic tumor heterogeneity in vitro, a co-culture system consisting of a malignant embryonal rhabdomyosarcoma (ERMS) cell line RD and a normal human skeletal muscle myoblast (HSMM) cell line was established by cell sheet technology. Various ratios of RDs to HSMMs were employed to understand the quantitative effect on intercellular interactions. Disruption of sheet structure was observed in heterogeneous cell sheets having a low ratio of RDs to HSMMs, whereas homogeneous HSMM or RD sheets maintained intact structure. Deeper exploration of dynamic tumor cell behavior inside HSMM sheets revealed that HSMM cell alignment was disrupted by highly motile RDs. This study demonstrated that RMS cells are capable of compromising their surrounding environment through induced decay of HSMMs alignment in a cell-based 3D system. This suggests that muscle disruption might be a major consequence of RMS cell invasion into muscles, which could be a promising target to preventing tumor invasion. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Edible Scaffolds Based on Non-Mammalian Biopolymers for Myoblast Growth

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    Javier Enrione

    2017-12-01

    Full Text Available In vitro meat has recently emerged as a new concept in food biotechnology. Methods to produce in vitro meat generally involve the growth of muscle cells that are cultured on scaffolds using bioreactors. Suitable scaffold design and manufacture are critical to downstream culture and meat production. Most current scaffolds are based on mammalian-derived biomaterials, the use of which is counter to the desire to obviate mammal slaughter in artificial meat production. Consequently, most of the knowledge is related to the design and control of scaffold properties based on these mammalian-sourced materials. To address this, four different scaffold materials were formulated using non-mammalian sources, namely, salmon gelatin, alginate, and additives including gelling agents and plasticizers. The scaffolds were produced using a freeze-drying process, and the physical, mechanical, and biological properties of the scaffolds were evaluated. The most promising scaffolds were produced from salmon gelatin, alginate, agarose, and glycerol, which exhibited relatively large pore sizes (~200 μm diameter and biocompatibility, permitting myoblast cell adhesion (~40% and growth (~24 h duplication time. The biodegradation profiles of the scaffolds were followed, and were observed to be less than 25% after 4 weeks. The scaffolds enabled suitable myogenic response, with high cell proliferation, viability, and adequate cell distribution throughout. This system composed of non-mammalian edible scaffold material and muscle-cells is promising for the production of in vitro meat.

  3. Graphene oxide increases the viability of C2C12 myoblasts microencapsulated in alginate.

    Science.gov (United States)

    Ciriza, J; Saenz del Burgo, L; Virumbrales-Muñoz, M; Ochoa, I; Fernandez, L J; Orive, G; Hernandez, R M; Pedraz, J L

    2015-09-30

    Cell microencapsulation represents a great promise for long-term drug delivery, but still several challenges need to be overcome before its translation into the clinic, such as the long term cell survival inside the capsules. On this regard, graphene oxide has shown to promote proliferation of different cell types either in two or three dimensions. Therefore, we planned to combine graphene oxide with the cell microencapsulation technology. We first studied the effect of this material on the stability of the capsules and next we analyzed the biocompatibility of this chemical compound with erythropoietin secreting C2C12 myoblasts within the microcapsule matrix. We produced 160 μm-diameter alginate microcapsules with increasing concentrations of graphene oxide and did not find modifications on the physicochemical parameters of traditional alginate microcapsules. Moreover, we observed that the viability of encapsulated cells within alginate microcapsules containing specific graphene oxide concentrations was enhanced. These results provide a relevant step for the future clinical application of graphene oxide on cell microencapsulation. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Effects of metal ions on proliferation of aortic smooth muscle cells and myoblastic cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Vorpahl, M.; Wiemann, M.; Bingmann, D. [Essen Univ. (Germany). Inst. fuer Physiologie; Brauer, H. [Werkstofftechnik, Univ. Essen (Germany)

    2001-12-01

    Metal ions released from implanted stents into the surrounding tissue may contribute to vascular reactions which cause restenosis in about 30%. This assumption prompted us to investigate short term effects of metal ions (Ag, Al, Cr, Fe, Mo, Ni, V, all applied as chloride salts) on proliferation of swine aortic smooth muscle cells (SMC) and a myoblastic cell line (C2C12). Cell confluence was 30 or 50% when metal ions were added and cell growth was monitored with the MTT-test after 2 days. A clear concentration dependence of acute toxicity of the different metal ions was found for both cell types. The order of toxicity indicated by IC50 values was V > Ni > Fe > Mo > Al > Cr. The nearly insoluble silverchloride exerted unclear effects. In experiments starting at high confluence, the apparent toxicity of Fe, Ni, and V was reduced. Al, which to our knowledge is not a major constituent in medical stents, was the only metal ion found here to cause a slightly increased proliferation, but this effect was restricted to the low concentration range (16-250 {mu}mol/l). In general, results for both cell types, C2C12 and SMC, were very similar. We conclude that short term effects of metal ions, which may be released in the interface of stent and vessel wall tissue, comprise a reduction rather than a stimulation of cell proliferation. However, restenosis may be initiated as a complex tissue reaction to primary toxic metal effects. (orig.)

  5. Edible Scaffolds Based on Non-Mammalian Biopolymers for Myoblast Growth.

    Science.gov (United States)

    Enrione, Javier; Blaker, Jonny J; Brown, Donald I; Weinstein-Oppenheimer, Caroline R; Pepczynska, Marzena; Olguín, Yusser; Sánchez, Elizabeth; Acevedo, Cristian A

    2017-12-08

    In vitro meat has recently emerged as a new concept in food biotechnology. Methods to produce in vitro meat generally involve the growth of muscle cells that are cultured on scaffolds using bioreactors. Suitable scaffold design and manufacture are critical to downstream culture and meat production. Most current scaffolds are based on mammalian-derived biomaterials, the use of which is counter to the desire to obviate mammal slaughter in artificial meat production. Consequently, most of the knowledge is related to the design and control of scaffold properties based on these mammalian-sourced materials. To address this, four different scaffold materials were formulated using non-mammalian sources, namely, salmon gelatin, alginate, and additives including gelling agents and plasticizers. The scaffolds were produced using a freeze-drying process, and the physical, mechanical, and biological properties of the scaffolds were evaluated. The most promising scaffolds were produced from salmon gelatin, alginate, agarose, and glycerol, which exhibited relatively large pore sizes (~200 μm diameter) and biocompatibility, permitting myoblast cell adhesion (~40%) and growth (~24 h duplication time). The biodegradation profiles of the scaffolds were followed, and were observed to be less than 25% after 4 weeks. The scaffolds enabled suitable myogenic response, with high cell proliferation, viability, and adequate cell distribution throughout. This system composed of non-mammalian edible scaffold material and muscle-cells is promising for the production of in vitro meat.

  6. Effect of IR Laser on Myoblasts: Prospects of Application for Counteracting Microgravity-Induced Muscle Atrophy

    Science.gov (United States)

    Monici, Monica; Cialdai, Francesca; Romano, Giovanni; Corsetto, Paola Antonia; Rizzo, Angela Maria; Caselli, Anna; Ranaldi, Francesco

    2013-02-01

    Microgravity-induced muscle atrophy is a problem of utmost importance for the impact it may have on the health and performance of astronauts. Therefore, appropriate countermeasures are needed to prevent disuse atrophy and favour muscle recovery. Muscle atrophy is characterized by loss of muscle mass and strength, and a shift in substrate utilization from fat to glucose, that leads to a reduced metabolic efficiency and enhanced fatigability. Laser therapy is already used in physical medicine and rehabilitation to accelerate muscle recovery and in sports medicine to prevent damages produced by metabolic disturbances and inflammatory reactions after heavy exercise. The aim of the research we present was to get insights on possible benefits deriving from the application of an advanced infrared laser system to counteract deficits of muscle energy metabolism and stimulate the recovery of the hypotrophic tissue. The source used was a Multiwave Locked System (MLS) laser, which combines continuous and pulsed emissions at 808 nm and 905 nm, respectively. We studied the effect of MLS treatment on morphology and energy metabolism of C2C12 cells, a widely accepted myoblast model, previously exposed to microgravity conditions modelled by a Random Positioning Machine. The MLS laser treatment was able to restore basal levels of serine/threonine protein phosphatase activity and to counteract cytoskeletal alterations and increase in glycolytic enzymes activity that occurred following the exposure to modelled microgravity. In conclusion, the results provide interesting insights for the application of infrared laser in the treatment of muscle atrophy.

  7. Protection by 6-aminonicotinamide against oxidative stress in cardiac cells

    DEFF Research Database (Denmark)

    Hofgaard, Johannes P; Sigurdardottir, Kristin Sigridur; Treiman, Marek

    2006-01-01

    Oxidative stress at the time of reperfusion is a major aspect of ischemia-reperfusion injury in heart as well as in other organs. There is a continuing interest in development of pharmacological approaches to alleviate this injury. 6-Aminonicotinamide (6AN) has been shown to diminish myocardial...... necrosis following global ischemia in an isolated rat heart, apparently by limiting the oxidative injury component. We therefore explored the antioxidative potential of 6AN in a model using H9C2(2-1) rat cardiac myoblasts exposed to H2O2 stress. Dependent on the specific protocol, 6AN pretreatment for 6....... The protective effect of 6AN was associated with a decrease in total cell content of the reduced glutathione (GSH) by 15-44%, indicative of an oxidative shift in the GSH/GSSG system redox potential. We propose that this redox shift caused an increased Ca2+ leak through ryanodine receptors, reflecting their known...

  8. The Use of Platelet-Rich and Platelet-Poor Plasma to Enhance Differentiation of Skeletal Myoblasts: Implications for the Use of Autologous Blood Products for Muscle Regeneration.

    Science.gov (United States)

    Miroshnychenko, Olga; Chang, Wen-Teh; Dragoo, Jason L

    2017-03-01

    Platelet-rich plasma (PRP) has been used to augment tissue repair and regeneration after musculoskeletal injury. However, there is increasing clinical evidence that PRP does not show a consistent clinical effect. Purpose/Hypothesis: This study aimed to compare the effects of the following non-neutrophil-containing (leukocyte-poor) plasma fractions on human skeletal muscle myoblast (HSMM) differentiation: (1) PRP, (2) modified PRP (Mod-PRP), in which transforming growth factor β1 (TGF-β1) and myostatin (MSTN) were depleted, and (3) platelet-poor plasma (PPP). The hypothesis was that leukocyte-poor PRP would lead to myoblast proliferation (not differentiation), whereas certain modifications of PRP preparations would increase myoblast differentiation, which is necessary for skeletal muscle regeneration. Controlled laboratory study. Blood from 7 human donors was individually processed to simultaneously create leukocyte-poor fractions: PRP, Mod-PRP, PPP, and secondarily spun PRP and Mod-PRP (PRPss and Mod-PRPss, respectively). Mod-PRP was produced by removing TGF-β1 and MSTN from PRP using antibodies attached to sterile beads, while a second-stage centrifugal spin of PRP was performed to remove platelets. The biologics were individually added to cell culture groups. Analysis for induction into myoblast differentiation pathways included Western blot analysis, reverse-transcription polymerase chain reaction, and immunohistochemistry, as well as confocal microscopy to assess polynucleated myotubule formation. HSMMs cultured with PRP showed an increase in proliferation but no evidence of differentiation. Western blot analysis confirmed that MSTN and TGF-β1 could be decreased in Mod-PRP using antibody-coated beads, but this modification mildly improved myoblast differentiation. However, cell culture with PPP, PRPss, and Mod-PRPss led to a decreased proliferation rate but a significant induction of myoblast differentiation verified by increased multinucleated myotubule

  9. Immortalized pathological human myoblasts: towards a universal tool for the study of neuromuscular disorders

    Directory of Open Access Journals (Sweden)

    Mamchaoui Kamel

    2011-11-01

    Full Text Available Abstract Background Investigations into both the pathophysiology and therapeutic targets in muscle dystrophies have been hampered by the limited proliferative capacity of human myoblasts. Isolation of reliable and stable immortalized cell lines from patient biopsies is a powerful tool for investigating pathological mechanisms, including those associated with muscle aging, and for developing innovative gene-based, cell-based or pharmacological biotherapies. Methods Using transduction with both telomerase-expressing and cyclin-dependent kinase 4-expressing vectors, we were able to generate a battery of immortalized human muscle stem-cell lines from patients with various neuromuscular disorders. Results The immortalized human cell lines from patients with Duchenne muscular dystrophy, facioscapulohumeral muscular dystrophy, oculopharyngeal muscular dystrophy, congenital muscular dystrophy, and limb-girdle muscular dystrophy type 2B had greatly increased proliferative capacity, and maintained their potential to differentiate both in vitro and in vivo after transplantation into regenerating muscle of immunodeficient mice. Conclusions Dystrophic cellular models are required as a supplement to animal models to assess cellular mechanisms, such as signaling defects, or to perform high-throughput screening for therapeutic molecules. These investigations have been conducted for many years on cells derived from animals, and would greatly benefit from having human cell models with prolonged proliferative capacity. Furthermore, the possibility to assess in vivo the regenerative capacity of these cells extends their potential use. The innovative cellular tools derived from several different neuromuscular diseases as described in this report will allow investigation of the pathophysiology of these disorders and assessment of new therapeutic strategies.

  10. Serum from human burn victims impairs myogenesis and protein synthesis in primary myoblasts

    Science.gov (United States)

    Corrick, Katie L.; Stec, Michael J.; Merritt, Edward K.; Windham, Samuel T.; Thomas, Steven J.; Cross, James M.; Bamman, Marcas M.

    2015-01-01

    The pathophysiological response to a severe burn injury involves a robust increase in circulating inflammatory/endocrine factors and a hypermetabolic state, both of which contribute to prolonged skeletal muscle atrophy. In order to characterize the role of circulating factors in muscle atrophy following a burn injury, human skeletal muscle satellite cells were grown in culture and differentiated to myoblasts/myotubes in media containing serum from burn patients or healthy, age, and sex-matched controls. While incubation in burn serum did not affect NFκB signaling, cells incubated in burn serum displayed a transient increase in STAT3 phosphorlyation (Tyr705) after 48 h of treatment with burn serum (≈ + 70%; P < 0.01), with these levels returning to normal by 96 h. Muscle cells differentiated in burn serum displayed reduced myogenic fusion signaling (phospho-STAT6 (Tyr641), ≈−75%; ADAM12, ≈-20%; both P < 0.01), and reduced levels of myogenin (≈−75%; P < 0.05). Concomitantly, myotubes differentiated in burn serum demonstrated impaired myogenesis (assessed by number of nuclei/myotube). Incubation in burn serum for 96 h did not increase proteolytic signaling (assessed via caspase-3 and ubiquitin levels), but reduced anabolic signaling [p-p70S6k (Ser421/Thr424), −30%; p-rpS6 (Ser240/244), ≈-50%] and impaired protein synthesis (−24%) (P < 0.05). This resulted in a loss of total protein content (−18%) and reduced cell size (−33%) (P < 0.05). Overall, incubation of human muscle cells in serum from burn patients results in impaired myogenesis and reduced myotube size, indicating that circulating factors may play a significant role in muscle loss and impaired muscle recovery following burn injury. PMID:26136691

  11. Plasma membrane characterization, by scanning electron microscopy, of multipotent myoblasts-derived populations sorted using dielectrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Muratore, Massimo, E-mail: M.Muratore@ed.ac.uk [Institute of Integrated Micro and Nano System, School of Engineering, The University of Edinburgh, Edinburgh EH9 3JF (United Kingdom); Mitchell, Steve [Institute of Molecular Plant Science, School of Biological Science, The University of Edinburgh, Edinburgh EH9 3JF (United Kingdom); Waterfall, Martin [Institute of Immunology and Infection Research, School of Biological Science, The University of Edinburgh, Edinburgh EH9 3JT (United Kingdom)

    2013-09-06

    Highlights: •Dielectrophoretic separation/sorting of multipotent cells. •Plasma membrane microvilli structure of C2C12 and fibroblasts by SEM microscopy. •Cell cycle determination by Ki-67 in DEP-sorted cells. •Plasma membrane differences responsible for changes in membrane capacitance. -- Abstract: Multipotent progenitor cells have shown promise for use in biomedical applications and regenerative medicine. The implementation of such cells for clinical application requires a synchronized, phenotypically and/or genotypically, homogenous cell population. Here we have demonstrated the implementation of a biological tag-free dielectrophoretic device used for discrimination of multipotent myoblastic C2C12 model. The multipotent capabilities in differentiation, for these cells, diminishes with higher passage number, so for cultures above 70 passages only a small percentage of cells is able to differentiate into terminal myotubes. In this work we demonstrated that we could recover, above 96% purity, specific cell types from a mixed population of cells at high passage number without any biological tag using dielectrophoresis. The purity of the samples was confirmed by cytometric analysis using the cell specific marker embryonic myosin. To further investigate the dielectric properties of the cell plasma membrane we co-culture C2C12 with similar size, when in suspension, GFP-positive fibroblast as feeder layer. The level of separation between the cell types was above 98% purity which was confirmed by flow cytometry. These levels of separation are assumed to account for cell size and for the plasma membrane morphological differences between C2C12 and fibroblast unrelated to the stages of the cell cycle which was assessed by immunofluorescence staining. Plasma membrane conformational differences were further confirmed by scanning electron microscopy.

  12. The Protective Effect of Silybin against Lasalocid Cytotoxic Exposure on Chicken and Rat Cell Lines

    Directory of Open Access Journals (Sweden)

    Lidia Radko

    2013-01-01

    Full Text Available Lasalocid, an ionophore coccidiostat, extensive use implies a risk of toxicological impacts. Protective effects of silybin, a herbal compound of Silybum marianum, are reported elsewhere. The aim of this study was to compare effects of the combined use of lasalocid and silybin in chicken hepatoma cells (LMH and rat myoblasts (L6 cell lines cultures. The cytoprotective effect resulting from an interaction of both pharmaceuticals was measured with the help of MTT reduction and, coomassie brilliant blue binding (CBB and LDH release assays. Isobolography and the combination index (CI estimated the nature and scale of interaction. In all performed tests, the lowest lasalocid EC50-values were obtained for chicken hepatocytes. In the rat myoblasts cultures, the lowest lasalocid EC50-values were found with LDH test. Simultaneously, a lack of silybin cytotoxic effect was proven for the studied cell lines. An interaction between both substances led to a considerable decrease of lasalocid cytotoxicity. The isobolograms and combination index showed a significant antagonistic nature of silybin effect in the course of lasalocid cytotoxicity. It is concluded that the mechanism of cytoprotection results from complex reaction at biochemical and biophysical endpoints during chicken hepatocytes and rat myoblasts cell lines exposure to silybin and lasalocid co-action.

  13. A novel whole-cell lysate kinase assay identifies substrates of the p38 MAPK in differentiating myoblasts

    Directory of Open Access Journals (Sweden)

    Knight James DR

    2012-03-01

    Full Text Available Abstract Background The p38α mitogen-activated protein kinase (MAPK is a critical mediator of myoblast differentiation, and does so in part through the phosphorylation and regulation of several transcription factors and chromatin remodelling proteins. However, whether p38α is involved in processes other than gene regulation during myogenesis is currently unknown, and why other p38 isoforms cannot compensate for its loss is unclear. Methods To further characterise the involvement of p38α during myoblast differentiation, we developed and applied a simple technique for identifying relevant in vivo kinase substrates and their phosphorylation sites. In addition to identifying substrates for one kinase, the technique can be used in vitro to compare multiple kinases in the same experiment, and we made use of this to study the substrate specificities of the p38α and β isoforms. Results Applying the technique to p38α resulted in the identification of seven in vivo phosphorylation sites on six proteins, four of which are cytoplasmic, in lysate derived from differentiating myoblasts. An in vitro comparison with p38β revealed that substrate specificity does not discriminate these two isoforms, but rather that their distinguishing characteristic appears to be cellular localisation. Conclusion Our results suggest p38α has a novel cytoplasmic role during myogenesis and that its unique cellular localisation may be why p38β and other isoforms cannot compensate for its absence. The substrate-finding approach presented here also provides a necessary tool for studying the hundreds of protein kinases that exist and for uncovering the deeper mechanisms of phosphorylation-dependent cell signalling.

  14. Myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese shorthorn cattle.

    Science.gov (United States)

    Takahashi, H; Sato, K; Yamaguchi, T; Miyake, M; Watanabe, H; Nagasawa, Y; Kitagawa, E; Terada, S; Urakawa, M; Rose, M T; McMahon, C D; Watanabe, K; Ohwada, S; Gotoh, T; Aso, H

    2014-07-01

    The purpose of this study was to determine whether myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese Shorthorn cattle. Plasma concentrations of glucose were lower in DM cattle than in NM cattle (P DM cattle than in NM cattle (P DM cattle did not differ with respect to skeletal muscle expression of GLUT1 and myocyte enhancer factor-2c (MEF2c), a transcription factor of GLUT4. In differentiated myoblasts, the expression of GLUT1, GLUT4, and MEF2c mRNAs was greater in DM cattle than in NM cattle (P DM cattle relative to that of NM cattle (P DM myoblasts (P DM cattle to produce muscle relative to the NM cattle may be due to their greater sensitivity to insulin and greater use of glucose. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. N-methyl D-aspartate receptor synaptonuclear signaling and neuronal migration factor (Nsmf) plays a novel role in myoblast proliferation.

    Science.gov (United States)

    Moon, Hyo Youl

    2015-01-01

    Myogenesis, the formation and regeneration of muscular tissue, is a fundamental factor in embryonic development. N-methyl D-aspartate (NMDA) receptor synaptonuclear signaling and neuronal migration factor (Nsmf) mediates NMDA receptor endocytosis in GnRH neuronal cells. NMDA receptor is involved in myoblast differentiation by regulating Ca2 (+) dependent fusion of myocytes. In this study, we investigated the role of Nsmf in myoblast proliferation and differentiation. Quantitative-PCR, immunoblotting, and immunohistochemistry results showed that the Nsmf expression levels increased during both the differentiation and proliferation of myocytes. Knockdown of Nsmf in myocytes by siRNA did not affect the myocyte differentiation marker myogenin. However, flow cytometry showed that the proliferation rate of the Nsmf-knockdown cells was reduced compared to the control cells. Therefore, our results indicate that Nsmf is a novel myogenic factor that can enhance myoblast proliferation. Furthermore, Nsmf may be an important therapeutic target in diseases associated with aging, muscular dystrophy, or cachexia.

  16. Insulin-like growth factor-1 (IGF-1) promotes myoblast proliferation and skeletal muscle growth of embryonic chickens via the PI3K/Akt signalling pathway.

    Science.gov (United States)

    Yu, Minli; Wang, Huan; Xu, Yali; Yu, Debing; Li, Dongfeng; Liu, Xiuhong; Du, Wenxing

    2015-08-01

    During embryonic development, IGF-1 fulfils crucial roles in skeletal myogenesis. However, the involvement of IGF-1-induced myoblast proliferation in muscle growth is still unclear. In the present study, we have characterised the role of IGF-1 in myoblast proliferation both in vitro and in vivo and have revealed novel details of how exogenous IGF-1 influences myogenic genes in chicken embryos. The results show that IGF-1 significantly induces the proliferation of cultured myoblasts in a dose-dependent manner. Additionally, the IGF-1 treatment significantly promoted myoblasts entering a new cell cycle and increasing the mRNA expression levels of cell cycle-dependent genes. However, these effects were inhibited by the PI3K inhibitor LY294002 and the Akt inhibitor KP372-1. These data indicated that the pro-proliferative effect of IGF-1 was mediated in response to the PI3K/Akt signalling pathway. Moreover, we also showed that exogenous IGF-1 stimulated myoblast proliferation in vivo. IGF-1 administration obviously promoted the incorporation of BrdU and remarkably increased the number of PAX7-positive cells in the skeletal muscle of chicken embryos. Administration of IGF-1 also significantly induced the upregulation of myogenic factors gene, the enhancement of c-Myc and the inhibition of myostatin (Mstn) expression. These findings demonstrate that IGF-1 has strong activity as a promoter of myoblast expansion and muscle fiber formation during early myogenesis. Therefore, this study offers insight into the mechanisms responsible for IGF-1-mediated stimulation of embryonic skeletal muscle development, which could have important implications for the improvement of chicken meat production. © 2015 International Federation for Cell Biology.

  17. Simultaneous transplantation of fetal ventral mesencephalic tissue and encapsulated genetically modified cells releasing GDNF in a hemi-parkinsonian rat model of Parkinson's disease

    DEFF Research Database (Denmark)

    Perez-Bouza, Alberto; Di Santo, Stefano; Seiler, Stefanie

    2017-01-01

    between groups were observed for the number of surviving TH-ir neurons or graft volume. In conclusion, our findings demonstrate that simultaneous transplantation of fetal VM tissue and encapsulated GDNF-releasing cells is feasible and support the graft survival and function. Pre-treatment of donor tissue......Transplantation of fetal ventral mesencephalic (VM) neurons for Parkinson's disease (PD) is limited by poor survival and suboptimal integration of grafted tissue into the host brain. In a 6-OHDA rat model of PD we investigated the feasibility of simultaneous transplantation of rat fetal VM tissue...... and polymer-encapsulated C2C12 myoblasts genetically modified to produce glial cell line-derived neurotrophic factor or mocktransfected myoblasts on graft function. Amphetamine-induced rotations were assessed prior and 2, 4, 6 and 9 weeks post-transplantation. We found that rats grafted with VM transplants...

  18. Pregnancy-associated Plasma Protein-A Regulates Myoblast Proliferation and Differentiation through an Insulin-like Growth Factor-dependent Mechanism*

    OpenAIRE

    Kumar, Ashok; Mohan, Subburaman; Newton, Jacqueline; Rehage, Mark; Tran, Kiet; Baylink, David J.; Qin, Xuezhong

    2005-01-01

    Pregnancy-associated plasma protein-A (PAPP-A), a member of the metalloproteinase superfamily, is an important regulator of mammalian growth and development. However, the role of PAPP-A and its mechanism of action in various cellular processes remain unknown. In this study, we have investigated the role of PAPP-A in skeletal myogenesis using C2C12 myoblasts. Recombinant PAPP-A was purified from the conditioned medium of HT1080 cells overexpressing PAPP-A. Treatment of C2C12 myoblasts with PAP...

  19. Myocyte-derived Tnfsf14 is a survival factor necessary for myoblast differentiation and skeletal muscle regeneration.

    Science.gov (United States)

    Waldemer-Streyer, R J; Chen, J

    2015-12-31

    Adult skeletal muscle tissue has a uniquely robust capacity for regeneration, which gradually declines with aging or is compromised in muscle diseases. The cellular mechanisms regulating adult myogenesis remain incompletely understood. Here we identify the cytokine tumor necrosis factor superfamily member 14 (Tnfsf14) as a positive regulator of myoblast differentiation in culture and muscle regeneration in vivo. We find that Tnfsf14, as well as its cognate receptors herpes virus entry mediator (HVEM) and lymphotoxin β receptor (LTβR), are expressed in both differentiating myocytes and regenerating myofibers. Depletion of Tnfsf14 or either receptor inhibits myoblast differentiation and promotes apoptosis. Our results also suggest that Tnfsf14 regulates myogenesis by supporting cell survival and maintaining a sufficient pool of cells for fusion. In addition, we show that Akt mediates the survival and myogenic function of Tnfsf14. Importantly, local knockdown of Tnfsf14 is found to impair injury-induced muscle regeneration in a mouse model, affirming an important physiological role for Tnfsf14 in myogenesis in vivo. Furthermore, we demonstrate that localized overexpression of Tnfsf14 potently enhances muscle regeneration, and that this regenerative capacity of Tnfsf14 is dependent on Akt signaling. Taken together, our findings reveal a novel regulator of skeletal myogenesis and implicate Tnfsf14 in future therapeutic development.

  20. Cyclic stretch facilitates myogenesis in C2C12 myoblasts and rescues thiazolidinedione-inhibited myotube formation

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    Ya-Ju eChang

    2016-03-01

    Full Text Available Thiazolidinedione (TZD, a specific peroxisome proliferator-activated receptor r (PPARr agonist, was developed to control blood glucose in diabetes patients. However, several side effects were reported that increased the risk of heart failure. We used C2C12 myoblasts to investigate the role of PPARs and their transcriptional activity during myotube formation. The role of mechanical stretch during myogenesis was also explored by applying cyclic stretch to the differentiating C2C12 myoblasts with 10% strain deformation at 1 Hz. The myogenesis medium (MM, composed of Dulbecco’s modified Eagle’s medium with 2% horse serum, facilitated myotube formation with increased myosin heavy chain and a-smooth muscle actin (a-SMA protein expression. The PPAR protein and PPAR response element (PPRE promoter activity decreased during MM induction. Cyclic stretch further facilitated the myogenesis in MM with increased a-SMA and decreased PPARr protein expression and inhibited PPRE promoter activity. Adding a PPARr agonist (TZD to the MM stopped the myogenesis and restored the PPRE promoter activity, whereas a PPARr antagonist (GW9662 significantly increased the myotube number and length. During the myogenesis induction, application of cyclic stretch rescued the inhibitory effects of TZD. These results provide novel perspectives for mechanical stretch to interplay and rescue the dysfunction of myogenesis with the involvement of PPARr and its target drugs.

  1. Efficient Restoration of the Dystrophin Gene Reading Frame and Protein Structure in DMD Myoblasts Using the CinDel Method

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    Jean-Paul Iyombe-Engembe

    2016-01-01

    Full Text Available The CRISPR/Cas9 system is a great revolution in biology. This technology allows the modification of genes in vitro and in vivo in a wide variety of living organisms. In most Duchenne muscular dystrophy (DMD patients, expression of dystrophin (DYS protein is disrupted because exon deletions result in a frame shift. We present here the CRISPR-induced deletion (CinDel, a new promising genome-editing technology to correct the DMD gene. This strategy is based on the use of two gRNAs targeting specifically exons that precede and follow the patient deletion in the DMD gene. This pair of gRNAs induced a precise large additional deletion leading to fusion of the targeted exons. Using an adequate pair of gRNAs, the deletion of parts of these exons and the intron separating them restored the DMD reading frame in 62% of the hybrid exons in vitro in DMD myoblasts and in vivo in electroporated hDMD/mdx mice. Moreover, adequate pairs of gRNAs also restored the normal spectrin-like repeat of the dystrophin rod domain; such restoration is not obtained by exon skipping or deletion of complete exons. The expression of an internally deleted DYS protein was detected following the formation of myotubes by the unselected, treated DMD myoblasts. Given that CinDel induces permanent reparation of the DMD gene, this treatment would not have to be repeated as it is the case for exon skipping induced by oligonucleotides.

  2. Efficient Restoration of the Dystrophin Gene Reading Frame and Protein Structure in DMD Myoblasts Using the CinDel Method.

    Science.gov (United States)

    Iyombe-Engembe, Jean-Paul; Ouellet, Dominique L; Barbeau, Xavier; Rousseau, Joël; Chapdelaine, Pierre; Lagüe, Patrick; Tremblay, Jacques P

    2016-01-26

    The CRISPR/Cas9 system is a great revolution in biology. This technology allows the modification of genes in vitro and in vivo in a wide variety of living organisms. In most Duchenne muscular dystrophy (DMD) patients, expression of dystrophin (DYS) protein is disrupted because exon deletions result in a frame shift. We present here the CRISPR-induced deletion (CinDel), a new promising genome-editing technology to correct the DMD gene. This strategy is based on the use of two gRNAs targeting specifically exons that precede and follow the patient deletion in the DMD gene. This pair of gRNAs induced a precise large additional deletion leading to fusion of the targeted exons. Using an adequate pair of gRNAs, the deletion of parts of these exons and the intron separating them restored the DMD reading frame in 62% of the hybrid exons in vitro in DMD myoblasts and in vivo in electroporated hDMD/mdx mice. Moreover, adequate pairs of gRNAs also restored the normal spectrin-like repeat of the dystrophin rod domain; such restoration is not obtained by exon skipping or deletion of complete exons. The expression of an internally deleted DYS protein was detected following the formation of myotubes by the unselected, treated DMD myoblasts. Given that CinDel induces permanent reparation of the DMD gene, this treatment would not have to be repeated as it is the case for exon skipping induced by oligonucleotides.

  3. In mouse myoblasts nuclear prosomes are associated with the nuclear matrix and accumulate preferentially in the perinucleolar areas.

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    De Conto, F; Pilotti, E; Razin, S V; Ferraglia, F; Géraud, G; Arcangeletti, C; Scherrer, K

    2000-07-01

    Prosomes are the core of 26S proteasomes, although they were originally observed as 20S particles associated with cytoplasmic mRNPs. Here we show for the first time that prosomes are also genuine constituents of the nuclear matrix, chromatin and the nuclear RNP networks. Using mouse myoblasts we tested three monoclonal antibodies recognising the prosomal subunits p23K, p27K and p30K, and found that the corresponding prosome subclasses are characterised by a variable distribution pattern within the nuclei. Their presence on the nuclear matrix, and most abundantly in the perinucleolar area, is of particular importance. When myoblasts fuse into myotubes, the distribution pattern of certain types of prosomes on the nuclear matrix changes drastically. Surprisingly, DNA strongly interferes with the detection of prosomal antigens by immunofluorescence methods, whereas RNA, histones and other proteins soluble in 2 M NaCl have no such effect. This 'masking' of prosomes can be completely overcome by extensive or even mild digestion with DNase I or restriction enzymes. Many nuclear prosomes can be solubilized by combined treatment with 0.5% Triton X-100 and 2 M NaCl, and others can be released by digestion of DNA and/or RNA, and about 10-20% of nuclear prosomes remain tightly bound to the protein-based nuclear matrix.

  4. Culture of skeletal myoblasts from human donors aged over 40 years: dynamics of cell growth and expression of differentiation markers

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    Cherubino Paolo

    2005-05-01

    Full Text Available Abstract Background Local myogenesis, neoangiogenesis and homing of progenitor cells from the bone marrow appear to contribute to repair of the infarcted myocardium. Implantation into heart tissues of autologous skeletal myoblasts has been associated with improved contractile function in animal models and in humans with acute myocardial ischemia. Since heart infarction is most prevalent in individuals of over 40 years of age, we tested whether culture methods available in our laboratory were adequate to obtain sufficient numbers of differentiated skeletal myoblasts from muscle biopsy specimens obtained from patients aged 41 to 91. Methods and results No matter of donor age, differentiated skeletal muscle cells could be produced in vitro in amounts adequate for cellular therapy (≥300 millions. Using desmin as a cytoplasmic marker, about 50% cultured cells were differentiated along myogenic lineages and expressed proteins proper of skeletal muscle (myosin type I and II, actin, actinin, spectrin and dystrophin. Cytogenetic alterations were not detected in cultured muscle cells that had undergone at least 10 population doublings. Molecular methods employed for the screening of persistent viral infections evidenced that HCV failed to replicate in muscle cells cultured from one patient with chronic HCV infection. Conclusion The proposed culture methods appear to hold promise for aged patients not only in the field of cardiovascular medicine, but also in the urologic and orthopedic fields.

  5. Rbfox2-coordinated alternative splicing of Mef2d and Rock2 controls myoblast fusion during myogenesis

    Science.gov (United States)

    Bland, Christopher S.; Kalsotra, Auinash; Scavuzzo, Marissa A.; Curk, Tomaz; Ule, Jernej; Li, Wei; Cooper, Thomas A.

    2014-01-01

    Summary Alternative splicing plays important regulatory roles during periods of physiological change. During development a large number of genes coordinately express protein isoform transitions regulated by alternative splicing, however, the mechanisms that coordinate splicing and the functional integration of the resultant tissue-specific protein isoforms are typically unknown. Here we show that the conserved Rbfox2 RNA binding protein regulates 30% of the splicing transitions observed during myogenesis and is required for the specific step of myoblast fusion. Integration of Rbfox2-dependent splicing outcomes from RNA-seq with Rbfox2 iCLIP data identified Mef2d and Rock2 as Rbfox2 splicing targets. Restored activities of Mef2d and Rock2 rescued myoblast fusion in Rbfox2 depleted cultures demonstrating functional cooperation of protein isoforms generated by coordinated alterative splicing. The results demonstrate that coordinated alternative splicing by a single RNA binding protein modulates transcription (Mef2d) and cell signaling (Rock2) programs to drive tissue-specific functions (cell fusion) to promote a developmental transition. PMID:25087874

  6. Melatonin attenuated brain death tissue extract-induced cardiac damage by suppressing DAMP signaling.

    Science.gov (United States)

    Sung, Pei-Hsun; Lee, Fan-Yen; Lin, Ling-Chun; Chen, Kuan-Hung; Lin, Hung-Sheng; Shao, Pei-Lin; Li, Yi-Chen; Chen, Yi-Ling; Lin, Kun-Chen; Yuen, Chun-Man; Chang, Hsueh-Wen; Lee, Mel S; Yip, Hon-Kan

    2018-01-09

    We tested the hypothesis that melatonin prevents brain death (BD) tissue extract (BDEX)-induced cardiac damage by suppressing inflammatory damage-associated molecular pattern (DAMP) signaling in rats. Six hours after BD induction, levels of a DAMP component (HMGB1) and inflammatory markers (TLR-2, TLR-4, MYD88, IκB, NF-κB, IL-1β, IFN-γ, TNF-α and IL-6) were higher in brain tissue from BD animals than controls. Levels of HMGB1 and inflammatory markers were higher in BDEX-treated H9C2 cardiac myoblasts than in cells treated with healthy brain tissue extract. These increases were attenuated by melatonin but re-induced with luzindole (all P DAMP inflammatory axis.

  7. Echinochrome A Increases Mitochondrial Mass and Function by Modulating Mitochondrial Biogenesis Regulatory Genes

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    Seung Hun Jeong

    2014-08-01

    Full Text Available Echinochrome A (Ech A is a natural pigment from sea urchins that has been reported to have antioxidant properties and a cardio protective effect against ischemia reperfusion injury. In this study, we ascertained whether Ech A enhances the mitochondrial biogenesis and oxidative phosphorylation in rat cardio myoblast H9c2 cells. To study the effects of Ech A on mitochondrial biogenesis, we measured mitochondrial mass, level of oxidative phosphorylation, and mitochondrial biogenesis regulatory gene expression. Ech A treatment did not induce cytotoxicity. However, Ech A treatment enhanced oxygen consumption rate and mitochondrial ATP level. Likewise, Ech A treatment increased mitochondrial contents in H9c2 cells. Furthermore, Ech A treatment up-regulated biogenesis of regulatory transcription genes, including proliferator-activated receptor gamma co-activator (PGC-1α, estrogen-related receptor (ERR-α, peroxisome proliferator-activator receptor (PPAR-γ, and nuclear respiratory factor (NRF-1 and such mitochondrial transcription regulatory genes as mitochondrial transcriptional factor A (TFAM, mitochondrial transcription factor B2 (TFB2M, mitochondrial DNA direct polymerase (POLMRT, single strand binding protein (SSBP and Tu translation elongation factor (TUFM. In conclusion, these data suggest that Ech A is a potentiated marine drug which enhances mitochondrial biogenesis.

  8. (-)-Epigallocatechin-3-gallate (EGCG) attenuates arsenic-induced cardiotoxicity in rats.

    Science.gov (United States)

    Sun, Tao-Li; Liu, Zhi; Qi, Zheng-Jun; Huang, Yong-Pan; Gao, Xiao-Qin; Zhang, Yan-Yan

    2016-07-01

    Chronic arsenic exposure in drinking water is associated with the abnormalities of cardiac tissue. Excessive generation of ROS induced by arsenic has a central role in arsenic-induced cardiotoxicity. (-)-Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, possesses a potent antioxidant capacity and exhibits extensive pharmacological activities. This study was aim to evaluate the effect of EGCG on arsenic-induced cardiotoxicity in vivo and in vitro. Treatment with NaAsO2 seriously affected the morphology and ultrastructure of myocardium, and induced cardiac injuries, oxidative stress, intracellular calcium accumulation and apoptosis in rats. In consistent with in vivo study, the injuries, oxidative stress and apoptosis were also observed in NaAsO2-treated H9c2 cells. All of these effects induced by NaAsO2 were attenuated by EGCG. These results suggest EGCG could attenuate NaAsO2-induced cardiotoxicity, and the mechanism may involve its potent antioxidant capacity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Nobiletin attenuates adverse cardiac remodeling after acute myocardial infarction in rats via restoring autophagy flux.

    Science.gov (United States)

    Wu, Xiaoqian; Zheng, Dechong; Qin, Yuyan; Liu, Zumei; Zhang, Guiping; Zhu, Xiaoyan; Zeng, Lihuan; Liang, Zhenye

    2017-10-14

    Our previous study showed that autophagy flux was impaired with sustained heart ischemia, which exacerbated adverse cardiac remodeling after acute myocardial infarction (AMI). Here we investigated whether Nobiletin, a citrus polymethoxylated flavonoids, could restore the autophagy flux and improve cardiac prognosis after AMI. AMI was induced by ligating left anterior descending (LAD) coronary artery in rats. Nobiletin improved the post-infarct cardiac dysfunction significantly and attenuated adverse cardiac remodeling. Meanwhile, Nobiletin protected H9C2 cells against oxygen glucose deprivation (OGD) in vitro. The impaired autophagy flux due to ischemia was ameliorated after Nobiletin treatment by testing the autophagy substrate, LC3BⅡ and P62 protein level both in vivo and in vitro. GFP-mRFP-LC3 adenovirus transfection also supported that Nobiletin restored the impaired autophagy flux. Specifically, the autophagy flux inhibitor, chloroquine, but not 3 MA, alleviated Nobiletin-mediated protection against OGD. Notably, Nobiletin does not affect the activation of classical upstream autophagy signaling pathways. However, Nobiletin increased the lysosome acidation which also supported that Nobiletin accelerated autophagy flux. Taken together, our findings suggested that Nobiletin restored impaired autophagy flux and protected against acute myocardial infarction, suggesting a potential role of autophagy flux in Nobiletin-mediated myocardial protection. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Concordant but Varied Phenotypes among Duchenne Muscular Dystrophy Patient-Specific Myoblasts Derived using a Human iPSC-Based Model

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    In Young Choi

    2016-06-01

    Full Text Available Duchenne muscular dystrophy (DMD remains an intractable genetic disease. Althogh there are several animal models of DMD, there is no human cell model that carries patient-specific DYSTROPHIN mutations. Here, we present a human DMD model using human induced pluripotent stem cells (hiPSCs. Our model reveals concordant disease-related phenotypes with patient-dependent variation, which are partially reversed by genetic and pharmacological approaches. Our “chemical-compound-based” strategy successfully directs hiPSCs into expandable myoblasts, which exhibit a myogenic transcriptional program, forming striated contractile myofibers and participating in muscle regeneration in vivo. DMD-hiPSC-derived myoblasts show disease-related phenotypes with patient-to-patient variability, including aberrant expression of inflammation or immune-response genes and collagens, increased BMP/TGFβ signaling, and reduced fusion competence. Furthermore, by genetic correction and pharmacological “dual-SMAD” inhibition, the DMD-hiPSC-derived myoblasts and genetically corrected isogenic myoblasts form “rescued” multi-nucleated myotubes. In conclusion, our findings demonstrate the feasibility of establishing a human “DMD-in-a-dish” model using hiPSC-based disease modeling.

  11. MiRNA-199a-3p Regulates C2C12 Myoblast Differentiation through IGF-1/AKT/mTOR Signal Pathway

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    Long Jia

    2013-12-01

    Full Text Available MicroRNAs constitute a class of ~22-nucleotide non-coding RNAs. They modulate gene expression by associating with the 3' untranslated regions (3' UTRs of messenger RNAs (mRNAs. Although multiple miRNAs are known to be regulated during myoblast differentiation, their individual roles in muscle development are still not fully understood. In this study, we showed that miR-199a-3p was highly expressed in skeletal muscle and was induced during C2C12 myoblasts differentiation. We also identified and confirmed several genes of the IGF-1/AKT/mTOR signal pathway, including IGF-1, mTOR, and RPS6KA6, as important cellular targets of miR-199a-3p in myoblasts. Overexpression of miR-199a-3p partially blocked C2C12 myoblast differentiation and the activation of AKT/mTOR signal pathway, while interference of miR-199a-3p by antisense oligonucleotides promoted C2C12 differentiation and myotube hypertrophy. Thus, our studies have established miR-199a-3p as a potential regulator of myogenesis through the suppression of IGF-1/AKT/mTOR signal pathway.

  12. Concordant but Varied Phenotypes among Duchenne Muscular Dystrophy Patient-Specific Myoblasts Derived using a Human iPSC-Based Model.

    Science.gov (United States)

    Choi, In Young; Lim, HoTae; Estrellas, Kenneth; Mula, Jyothi; Cohen, Tatiana V; Zhang, Yuanfan; Donnelly, Christopher J; Richard, Jean-Philippe; Kim, Yong Jun; Kim, Hyesoo; Kazuki, Yasuhiro; Oshimura, Mitsuo; Li, Hongmei Lisa; Hotta, Akitsu; Rothstein, Jeffrey; Maragakis, Nicholas; Wagner, Kathryn R; Lee, Gabsang

    2016-06-07

    Duchenne muscular dystrophy (DMD) remains an intractable genetic disease. Althogh there are several animal models of DMD, there is no human cell model that carries patient-specific DYSTROPHIN mutations. Here, we present a human DMD model using human induced pluripotent stem cells (hiPSCs). Our model reveals concordant disease-related phenotypes with patient-dependent variation, which are partially reversed by genetic and pharmacological approaches. Our "chemical-compound-based" strategy successfully directs hiPSCs into expandable myoblasts, which exhibit a myogenic transcriptional program, forming striated contractile myofibers and participating in muscle regeneration in vivo. DMD-hiPSC-derived myoblasts show disease-related phenotypes with patient-to-patient variability, including aberrant expression of inflammation or immune-response genes and collagens, increased BMP/TGFβ signaling, and reduced fusion competence. Furthermore, by genetic correction and pharmacological "dual-SMAD" inhibition, the DMD-hiPSC-derived myoblasts and genetically corrected isogenic myoblasts form "rescued" multi-nucleated myotubes. In conclusion, our findings demonstrate the feasibility of establishing a human "DMD-in-a-dish" model using hiPSC-based disease modeling. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. A double-blind, randomized, controlled, multicenter study to assess the safety and cardiovascular effects of skeletal myoblast implantation by catheter delivery in patients with chronic heart failure after myocardial infarction.

    Science.gov (United States)

    Povsic, Thomas J; O'Connor, Christopher M; Henry, Timothy; Taussig, Andrew; Kereiakes, Dean J; Fortuin, F David; Niederman, Alan; Schatz, Richard; Spencer, Richard; Owens, Douglas; Banks, Missy; Joseph, Diane; Roberts, Rhonda; Alexander, John H; Sherman, Warren

    2011-10-01

    We sought to determine the safety and preliminary efficacy of transcatheter intramyocardial administration of myoblasts in patients with heart failure (HF). MARVEL is a randomized placebo-controlled trial of image-guided, catheter-based intramyocardial injection of placebo or myoblasts (400 or 800 million) in patients with class II to IV HF and ejection fraction stopping the study for financial reasons. At 6 months, similar numbers of events occurred in each group: 8 (placebo), 7 (low dose), and 8 (high dose), without deaths. Ventricular tachycardia responsive to amiodarone was more frequent in myoblast-treated patients: 1 (placebo), 3 (low dose), and 4 (high dose). A trend toward improvement in functional capacity was noted in myoblast-treated groups (Δ6-minute walk test of -3.6 vs +95.6 vs +85.5 m [placebo vs low dose vs high dose; P = .50]) without significant changes in Minnesota Living With HF scores. In HF patients with chronic postinfarction cardiomyopathy, transcatheter administration of myoblasts in doses of 400 to 800 million cells is feasible and may lead to important clinical benefits. Ventricular tachycardia may be provoked by myoblast injection but appears to be a transient and treatable problem. A large-scale outcome trial of myoblast administration in HF patients with postinfarction cardiomyopathy is feasible and warranted. Copyright © 2011 Mosby, Inc. All rights reserved.

  14. Dock mediates Scar- and WASp-dependent actin polymerization through interaction with cell adhesion molecules in founder cells and fusion-competent myoblasts.

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    Kaipa, Balasankara Reddy; Shao, Huanjie; Schäfer, Gritt; Trinkewitz, Tatjana; Groth, Verena; Liu, Jianqi; Beck, Lothar; Bogdan, Sven; Abmayr, Susan M; Önel, Susanne-Filiz

    2013-01-01

    The formation of the larval body wall musculature of Drosophila depends on the asymmetric fusion of two myoblast types, founder cells (FCs) and fusion-competent myoblasts (FCMs). Recent studies have established an essential function of Arp2/3-based actin polymerization during myoblast fusion, formation of a dense actin focus at the site of fusion in FCMs, and a thin sheath of actin in FCs and/or growing muscles. The formation of these actin structures depends on recognition and adhesion of myoblasts that is mediated by cell surface receptors of the immunoglobulin superfamily. However, the connection of the cell surface receptors with Arp2/3-based actin polymerization is poorly understood. To date only the SH2-SH3 adaptor protein Crk has been suggested to link cell adhesion with Arp2/3-based actin polymerization in FCMs. Here, we propose that the SH2-SH3 adaptor protein Dock, like Crk, links cell adhesion with actin polymerization. We show that Dock is expressed in FCs and FCMs and colocalizes with the cell adhesion proteins Sns and Duf at cell-cell contact points. Biochemical data in this study indicate that different domains of Dock are involved in binding the cell adhesion molecules Duf, Rst, Sns and Hbs. We emphasize the importance of these interactions by quantifying the enhanced myoblast fusion defects in duf dock, sns dock and hbs dock double mutants. Additionally, we show that Dock interacts biochemically and genetically with Drosophila Scar, Vrp1 and WASp. Based on these data, we propose that Dock links cell adhesion in FCs and FCMs with either Scar- or Vrp1-WASp-dependent Arp2/3 activation.

  15. The cAMP Response Element Binding protein (CREB) is activated by Insulin-like Growth Factor-1 (IGF-1) and regulates myostatin gene expression in skeletal myoblast

    Energy Technology Data Exchange (ETDEWEB)

    Zuloaga, R. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Fuentes, E.N.; Molina, A. [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile); Valdés, J.A., E-mail: jvaldes@unab.cl [Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), Víctor Lamas 1290, PO Box 160-C, Concepción (Chile)

    2013-10-18

    Highlights: •IGF-1 induces the activation of CREB via IGF-1R/PI3K/PLC signaling pathway. •Calcium dependent signaling pathways regulate myostatin gene expression. •IGF-1 regulates myostatin gene expression via CREB transcription in skeletal myoblast. -- Abstract: Myostatin, a member of the Transforming Growth Factor beta (TGF-β) superfamily, plays an important role as a negative regulator of skeletal muscle growth and differentiation. We have previously reported that IGF-1 induces a transient myostatin mRNA expression, through the activation of the Nuclear Factor of Activated T cells (NFAT) in an IP{sub 3}/calcium-dependent manner. Here we examined the activation of CREB transcription factor as downstream targets of IGF-1 during myoblast differentiation and its role as a regulator of myostatin gene expression. In cultured skeletal myoblast, IGF-1 induced the phosphorylation and transcriptional activation of CREB via IGF-1 Receptor/Phosphatidylinositol 3-Kinase (PI3K)/Phospholipase C gamma (PLC γ), signaling pathways. Also, IGF-1 induced calcium-dependent molecules such as Calmodulin Kinase II (CaMK II), Extracellular signal-regulated Kinases (ERK), Protein Kinase C (PKC). Additionally, we examined myostatin mRNA levels and myostatin promoter activity in differentiated myoblasts stimulated with IGF-1. We found a significant increase in mRNA contents of myostatin and its reporter activity after treatment with IGF-1. The expression of myostatin in differentiated myoblast was downregulated by the transfection of siRNA–CREB and by pharmacological inhibitors of the signaling pathways involved in CREB activation. By using pharmacological and genetic approaches together these data demonstrate that IGF-1 regulates the myostatin gene expression via CREB transcription factor during muscle cell differentiation.

  16. Long-Term Endurance Exercise in Humans Stimulates Cell Fusion of Myoblasts along with Fusogenic Endogenous Retroviral Genes In Vivo.

    Science.gov (United States)

    Frese, Sebastian; Ruebner, Matthias; Suhr, Frank; Konou, Thierry M; Tappe, Kim A; Toigo, Marco; Jung, Hans H; Henke, Christine; Steigleder, Ruth; Strissel, Pamela L; Huebner, Hanna; Beckmann, Matthias W; van der Keylen, Piet; Schoser, Benedikt; Schiffer, Thorsten; Frese, Laura; Bloch, Wilhelm; Strick, Reiner

    2015-01-01

    Myogenesis is defined as growth, differentiation and repair of muscles where cell fusion of myoblasts to multinucleated myofibers is one major characteristic. Other cell fusion events in humans are found with bone resorbing osteoclasts and placental syncytiotrophoblasts. No unifying gene regulation for natural cell fusions has been found. We analyzed skeletal muscle biopsies of competitive cyclists for muscle-specific attributes and expression of human endogenous retrovirus (ERV) envelope genes due to their involvement in cell fusion of osteoclasts and syncytiotrophoblasts. Comparing muscle biopsies from post- with the pre-competitive seasons a significant 2.25-fold increase of myonuclei/mm fiber, a 2.38-fold decrease of fiber area/nucleus and a 3.1-fold decrease of satellite cells (SCs) occurred. We propose that during the pre-competitive season SC proliferation occurred following with increased cell fusion during the competitive season. Expression of twenty-two envelope genes of muscle biopsies demonstrated a significant increase of putative muscle-cell fusogenic genes Syncytin-1 and Syncytin-3, but also for the non-fusogenic erv3. Immunohistochemistry analyses showed that Syncytin-1 mainly localized to the sarcolemma of myofibers positive for myosin heavy-chain isotypes. Cellular receptors SLC1A4 and SLC1A5 of Syncytin-1 showed significant decrease of expression in post-competitive muscles compared with the pre-competitive season, but only SLC1A4 protein expression localized throughout the myofiber. Erv3 protein was strongly expressed throughout the myofiber, whereas envK1-7 localized to SC nuclei and myonuclei. Syncytin-1 transcription factors, PPARγ and RXRα, showed no protein expression in the myofiber, whereas the pCREB-Ser133 activator of Syncytin-1 was enriched to SC nuclei and myonuclei. Syncytin-1, Syncytin-3, SLC1A4 and PAX7 gene regulations along with MyoD1 and myogenin were verified during proliferating or actively-fusing human primary myoblast cell

  17. Long-Term Endurance Exercise in Humans Stimulates Cell Fusion of Myoblasts along with Fusogenic Endogenous Retroviral Genes In Vivo.

    Directory of Open Access Journals (Sweden)

    Sebastian Frese

    Full Text Available Myogenesis is defined as growth, differentiation and repair of muscles where cell fusion of myoblasts to multinucleated myofibers is one major characteristic. Other cell fusion events in humans are found with bone resorbing osteoclasts and placental syncytiotrophoblasts. No unifying gene regulation for natural cell fusions has been found. We analyzed skeletal muscle biopsies of competitive cyclists for muscle-specific attributes and expression of human endogenous retrovirus (ERV envelope genes due to their involvement in cell fusion of osteoclasts and syncytiotrophoblasts. Comparing muscle biopsies from post- with the pre-competitive seasons a significant 2.25-fold increase of myonuclei/mm fiber, a 2.38-fold decrease of fiber area/nucleus and a 3.1-fold decrease of satellite cells (SCs occurred. We propose that during the pre-competitive season SC proliferation occurred following with increased cell fusion during the competitive season. Expression of twenty-two envelope genes of muscle biopsies demonstrated a significant increase of putative muscle-cell fusogenic genes Syncytin-1 and Syncytin-3, but also for the non-fusogenic erv3. Immunohistochemistry analyses showed that Syncytin-1 mainly localized to the sarcolemma of myofibers positive for myosin heavy-chain isotypes. Cellular receptors SLC1A4 and SLC1A5 of Syncytin-1 showed significant decrease of expression in post-competitive muscles compared with the pre-competitive season, but only SLC1A4 protein expression localized throughout the myofiber. Erv3 protein was strongly expressed throughout the myofiber, whereas envK1-7 localized to SC nuclei and myonuclei. Syncytin-1 transcription factors, PPARγ and RXRα, showed no protein expression in the myofiber, whereas the pCREB-Ser133 activator of Syncytin-1 was enriched to SC nuclei and myonuclei. Syncytin-1, Syncytin-3, SLC1A4 and PAX7 gene regulations along with MyoD1 and myogenin were verified during proliferating or actively-fusing human

  18. Conessine Interferes with Oxidative Stress-Induced C2C12 Myoblast Cell Death through Inhibition of Autophagic Flux.

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    Hyunju Kim

    Full Text Available Conessine, a steroidal alkaloid isolated from Holarrhena floribunda, has anti-malarial activity and interacts with the histamine H3 receptor. However, the cellular effects of conessine are poorly understood. Accordingly, we evaluated the involvement of conessine in the regulation of autophagy. We searched natural compounds that modulate autophagy, and conessine was identified as an inhibitor of autophagic flux. Conessine treatment induced the formation of autophagosomes, and p62, an autophagic adapter, accumulated in the autophagosomes. Reactive oxygen species such as hydrogen peroxide (H2O2 result in muscle cell death by inducing excessive autophagic flux. Treatment with conessine inhibited H2O2-induced autophagic flux in C2C12 myoblast cells and also interfered with cell death. Our results indicate that conessine has the potential effect to inhibit muscle cell death by interfering with autophagic flux.

  19. Conessine Interferes with Oxidative Stress-Induced C2C12 Myoblast Cell Death through Inhibition of Autophagic Flux.

    Science.gov (United States)

    Kim, Hyunju; Lee, Kang Il; Jang, Minsu; Namkoong, Sim; Park, Rackhyun; Ju, Hyunwoo; Choi, Inho; Oh, Won Keun; Park, Junsoo

    2016-01-01

    Conessine, a steroidal alkaloid isolated from Holarrhena floribunda, has anti-malarial activity and interacts with the histamine H3 receptor. However, the cellular effects of conessine are poorly understood. Accordingly, we evaluated the involvement of conessine in the regulation of autophagy. We searched natural compounds that modulate autophagy, and conessine was identified as an inhibitor of autophagic flux. Conessine treatment induced the formation of autophagosomes, and p62, an autophagic adapter, accumulated in the autophagosomes. Reactive oxygen species such as hydrogen peroxide (H2O2) result in muscle cell death by inducing excessive autophagic flux. Treatment with conessine inhibited H2O2-induced autophagic flux in C2C12 myoblast cells and also interfered with cell death. Our results indicate that conessine has the potential effect to inhibit muscle cell death by interfering with autophagic flux.

  20. Glycogenome expression dynamics during mouse C2C12 myoblast differentiation suggests a sequential reorganization of membrane glycoconjugates

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    Dupuy Fabrice

    2009-10-01

    Full Text Available Abstract Background Several global transcriptomic and proteomic approaches have been applied in order to obtain new molecular insights on skeletal myogenesis, but none has generated any specific data on glycogenome expression, and thus on the role of glycan structures in this process, despite the involvement of glycoconjugates in various biological events including differentiation and development. In the present study, a quantitative real-time RT-PCR technology was used to profile the dynamic expression of 375 glycogenes during the differentiation of C2C12 myoblasts into myotubes. Results Of the 276 genes expressed, 95 exhibited altered mRNA expression when C2C12 cells differentiated and 37 displayed more than 4-fold up- or down-regulations. Principal Component Analysis and Hierarchical Component Analysis of the expression dynamics identified three groups of coordinately and sequentially regulated genes. The first group included 12 down-regulated genes, the second group four genes with an expression peak at 24 h of differentiation, and the last 21 up-regulated genes. These genes mainly encode cell adhesion molecules and key enzymes involved in the biosynthesis of glycosaminoglycans and glycolipids (neolactoseries, lactoseries and ganglioseries, providing a clearer indication of how the plasma membrane and extracellular matrix may be modified prior to cell fusion. In particular, an increase in the quantity of ganglioside GM3 at the cell surface of myoblasts is suggestive of its potential role during the initial steps of myogenic differentiation. Conclusion For the first time, these results provide a broad description of the expression dynamics of glycogenes during C2C12 differentiation. Among the 37 highly deregulated glycogenes, 29 had never been associated with myogenesis. Their biological functions suggest new roles for glycans in skeletal myogenesis.

  1. Functional analysis of SH3 domain containing ring finger 2 during the myogenic differentiation of quail myoblast cells

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    Si Won Kim

    2017-08-01

    Full Text Available Objective Owing to the public availability of complete genome sequences, including avian species, massive bioinformatics analyses may be conducted for computational gene prediction and the identification of gene regulatory networks through various informatics tools. However, to evaluate the biofunctional activity of a predicted target gene, in vivo and in vitro functional genomic analyses should be a prerequisite. Methods Due to a lack of quail genomic sequence information, we first identified the partial genomic structure and sequences of the quail SH3 domain containing ring finger 2 (SH3RF2 gene. Subsequently, SH3RF2 was knocked out using clustered regularly interspaced short palindromic repeat/Cas9 technology and single cell-derived SH3RF2 mutant sublines were established to study the biofunctional activity of SH3RF2 in quail myoblast (QM7 cells during muscle differentiation. Results Through a T7 endonuclease I assay and genotyping analysis, we established an SH3RF2 knockout (KO QM7#4 subline with 61 and 155 nucleotide deletion mutations in SH3RF2. After the induction of myotube differentiation, the expression profiles were analyzed and compared between regular QM7 and SH3RF2 KO QM7#4 cells by global RNA sequencing and bioinformatics analysis. Conclusion We did not detect any statistically significant role of SH3RF2 during myotube differentiation in QM7 myoblast cells. However, additional experiments are necessary to examine the biofunctional activity of SH3RF2 in cell proliferation and muscle growth.

  2. Detection of Pancreatic Cancer-Induced Cachexia Using a Fluorescent Myoblast Reporter System and Analysis of Metabolite Abundance.

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    Winnard, Paul T; Bharti, Santosh K; Penet, Marie-France; Marik, Radharani; Mironchik, Yelena; Wildes, Flonne; Maitra, Anirban; Bhujwalla, Zaver M

    2016-03-15

    The dire effects of cancer-induced cachexia undermine treatment and contribute to decreased survival rates. Therapeutic options for this syndrome are limited, and therefore efforts to identify signs of precachexia in cancer patients are necessary for early intervention. The applications of molecular and functional imaging that would enable a whole-body "holistic" approach to this problem may lead to new insights and advances for diagnosis and treatment of this syndrome. Here we have developed a myoblast optical reporter system with the purpose of identifying early cachectic events. We generated a myoblast cell line expressing a dual tdTomato:GFP construct that was grafted onto the muscle of mice-bearing human pancreatic cancer xenografts to provide noninvasive live imaging of events associated with cancer-induced cachexia (i.e., weight loss). Real-time optical imaging detected a strong tdTomato fluorescent signal from skeletal muscle grafts in mice with weight losses of only 1.2% to 2.7% and tumor burdens of only approximately 79 to 170 mm(3). Weight loss in cachectic animals was also associated with a depletion of lipid, cholesterol, valine, and alanine levels, which may provide informative biomarkers of cachexia. Taken together, our findings demonstrate the utility of a reporter system that is capable of tracking tumor-induced weight loss, an early marker of cachexia. Future studies incorporating resected tissue from human pancreatic ductal adenocarcinoma into a reporter-carrying mouse may be able to provide a risk assessment of cachexia, with possible implications for therapeutic development. ©2015 American Association for Cancer Research.

  3. A Pitx2-MicroRNA Pathway Modulates Cell Proliferation in Myoblasts and Skeletal-Muscle Satellite Cells and Promotes Their Commitment to a Myogenic Cell Fate

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    Lozano-Velasco, Estefanía; Vallejo, Daniel; Esteban, Francisco J.; Doherty, Chris; Hernández-Torres, Francisco; Franco, Diego

    2015-01-01

    The acquisition of a proliferating-cell status from a quiescent state as well as the shift between proliferation and differentiation are key developmental steps in skeletal-muscle stem cells (satellite cells) to provide proper muscle regeneration. However, how satellite cell proliferation is regulated is not fully understood. Here, we report that the c-isoform of the transcription factor Pitx2 increases cell proliferation in myoblasts by downregulating microRNA 15b (miR-15b), miR-23b, miR-106b, and miR-503. This Pitx2c-microRNA (miRNA) pathway also regulates cell proliferation in early-activated satellite cells, enhancing Myf5+ satellite cells and thereby promoting their commitment to a myogenic cell fate. This study reveals unknown functions of several miRNAs in myoblast and satellite cell behavior and thus may have future applications in regenerative medicine. PMID:26055324

  4. Static magnetic fields inhibit proliferation and disperse subcellular localization of gamma complex protein3 in cultured C2C12 myoblast cells.

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    Kim, SeungChan; Im, Wooseok

    2010-05-01

    Magnetic fields may delay the rate of cell cycle progression, and there are reports that magnetic fields induce neurite outgrowth in cultured neuronal cells. To demonstrate whether magnetic field also effects on myoblast cells in cell growth, C2C12 cell lines were cultured and 2000G static magnetic field was applied. After 48 h of incubation, both the WST-1 assay (0.01 magnetic fields inhibit the proliferation of cultured C2C12 cells. Immunocytochemistry for alpha and tubulin gamma complex protein (TUBA and GCP3) was made and applying a static magnetic field-dispersed tubulin GCP3 formation, a intracellular apparatus for tubulin structuring in cell division. This protein expression was not altered by western blot. This study indicates that applying a static magnetic field alters the subcellular localizing of GCP3, and may delay the cell growth in cultured C2C12 myoblast cells.

  5. Myosin heavy chain-like localizes at cell contact sites during Drosophila myoblast fusion and interacts in vitro with Rolling pebbles 7

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    Bonn, Bettina R.; Rudolf, Anja; Hornbruch-Freitag, Christina; Daum, Gabor; Kuckwa, Jessica; Kastl, Lena; Buttgereit, Detlev [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany); Renkawitz-Pohl, Renate, E-mail: renkawit@biologie.uni-marburg.de [Developmental Biology, Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Strasse 8, 35037 Marburg (Germany)

    2013-02-15

    Besides representing the sarcomeric thick filaments, myosins are involved in many cellular transport and motility processes. Myosin heavy chains are grouped into 18 classes. Here we show that in Drosophila, the unconventional group XVIII myosin heavy chain-like (Mhcl) is transcribed in the mesoderm of embryos, most prominently in founder cells (FCs). An ectopically expressed GFP-tagged Mhcl localizes in the growing muscle at cell–cell contacts towards the attached fusion competent myoblast (FCM). We further show that Mhcl interacts in vitro with the essential fusion protein Rolling pebbles 7 (Rols7), which is part of a protein complex established at cell contact sites (Fusion-restricted Myogenic-Adhesive Structure or FuRMAS). Here, branched F-actin is likely needed to widen the fusion pore and to integrate the myoblast into the growing muscle. We show that the localization of Mhcl is dependent on the presence of Rols7, and we postulate that Mhcl acts at the FuRMAS as an actin motor protein. We further show that Mhcl deficient embryos develop a wild-type musculature. We thus propose that Mhcl functions redundantly to other myosin heavy chains in myoblasts. Lastly, we found that the protein is detectable adjacent to the sarcomeric Z-discs, suggesting an additional function in mature muscles. - Highlights: ► The class XVIII myosin encoding gene Mhcl is transcribed in the mesoderm. ► Mhcl localization at contact sites of fusing myoblasts depends on Rols7. ► Mhcl interacts in vitro with Rols7 which is essential for myogenesis. ► Functional redundancy with other myosins is likely as mutants show no muscle defects. ► Mhcl localizes adjacent to Z-discs of sarcomeres and might support muscle integrity.

  6. Mechano-growth factor peptide, the COOH terminus of unprocessed insulin-like growth factor 1, has no apparent effect on myoblasts or primary muscle stem cells.

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    Fornaro, Mara; Hinken, Aaron C; Needle, Saul; Hu, Erding; Trendelenburg, Anne-Ulrike; Mayer, Angelika; Rosenstiel, Antonia; Chang, Calvin; Meier, Viktor; Billin, Andrew N; Becherer, J David; Brace, Arthur D; Evans, William J; Glass, David J; Russell, Alan J

    2014-01-15

    A splice form of IGF-1, IGF-1Eb, is upregulated after exercise or injury. Physiological responses have been ascribed to the 24-amino acid COOH-terminal peptide that is cleaved from the NH3-terminal 70-amino acid mature IGF-1 protein. This COOH-terminal peptide was termed "mechano-growth factor" (MGF). Activities claimed for the MGF peptide included enhancing muscle satellite cell proliferation and delaying myoblast fusion. As such, MGF could represent a promising strategy to improve muscle regeneration. Thus, at our two pharmaceutical companies, we attempted to reproduce the claimed effect of MGF peptides on human and mouse muscle myoblast proliferation and differentiation in vitro. Concentrations of peptide up to 500 ng/ml failed to increase the proliferation of C2C12 cells or primary human skeletal muscle myoblasts. In contrast, all cell types exhibited a proliferative response to mature IGF-1 or full-length IGF-1Eb. MGF also failed to inhibit the differentiation of myoblasts into myotubes. To address whether the response to MGF was lost in these tissue culture lines, we measured proliferation and differentiation of primary mouse skeletal muscle stem cells exposed to MGF. This, too, failed to demonstrate a significant effect. Finally, we tested whether MGF could alter a separate documented in vitro effect of the peptide, activation of p-ERK, but not p-Akt, in cardiac myocytes. Although a robust response to IGF-1 was observed, there were no demonstrated activating responses from the native or a stabilized MGF peptide. These results call in to question whether there is a physiological role for MGF.

  7. Mouse C2 myoblast cells resist HVJ (Sendai virus)-mediated cell fusion in the proliferating stage but become capable of fusion after differentiation.

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    Hirayama, E; Nakanishi, M; Honda, N; Kim, J

    1999-05-01

    To investigate the mechanism of myoblast fusion, we attempted to prepare artificial myotubes of mouse C2 myoblast cells using the hemagglutinating virus of Japan (HVJ, Sendai virus). Proliferating C2 cells showed strong resistance to HVJ-mediated cell fusion and remained morphologically unchanged even though massive numbers of virions adsorbed onto their surface. They showed no membrane disruption, which occurs in the early stage of cell fusion induced by HVJ. These observations suggest that proliferating C2 cells are resistant to HVJ-mediated cell fusion. However, upon induction of differentiation, C2 cells gradually became capable of fusion induced by HVJ and then even generated heterokaryons with Ehrlich ascites tumor cells. When differentiated C2 cells that had become fusion-sensitive were treated with HVJ in the presence of EDTA, they did not fuse but degenerated, suggesting that their cell membranes were transiently disrupted by interaction with HVJ. These results suggest that the cell membranes of myoblasts change to a fusion-capable state during the process of differentiation.

  8. DNA replication timing is maintained genome-wide in primary human myoblasts independent of D4Z4 contraction in FSH muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Benjamin D Pope

    Full Text Available Facioscapulohumeral muscular dystrophy (FSHD is linked to contraction of an array of tandem 3.3-kb repeats (D4Z4 at 4q35.2 from 11-100 copies to 1-10 copies. The extent to which D4Z4 contraction at 4q35.2 affects overall 4q35.2 chromatin organization remains unclear. Because DNA replication timing is highly predictive of long-range chromatin interactions, we generated genome-wide replication-timing profiles for FSHD and control myogenic precursor cells. We compared non-immortalized myoblasts from four FSHD patients and three control individuals to each other and to a variety of other human cell types. This study also represents the first genome-wide comparison of replication timing profiles in non-immortalized human cell cultures. Myoblasts from both control and FSHD individuals all shared a myoblast-specific replication profile. In contrast, male and female individuals were readily distinguished by monoallelic differences in replication timing at DXZ4 and other regions across the X chromosome affected by X inactivation. We conclude that replication timing is a robust cell-type specific feature that is unaffected by FSHD-related D4Z4 contraction.

  9. Stimulating effect of graphene oxide on myogenesis of C2C12 myoblasts on RGD peptide-decorated PLGA nanofiber matrices.

    Science.gov (United States)

    Shin, Yong Cheol; Lee, Jong Ho; Kim, Min Jeong; Hong, Suck Won; Kim, Bongju; Hyun, Jung Keun; Choi, Yu Suk; Park, Jong-Chul; Han, Dong-Wook

    2015-01-01

    In the field of biomedical engineering, many studies have focused on the possible applications of graphene and related nanomaterials due to their potential for use as scaffolds, coating materials and delivery carriers. On the other hand, electrospun nanofiber matrices composed of diverse biocompatible polymers have attracted tremendous attention for tissue engineering and regenerative medicine. However, their combination is intriguing and still challenging. In the present study, we fabricated nanofiber matrices composed of M13 bacteriophage with RGD peptide displayed on its surface (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) and characterized their physicochemical properties. In addition, the effect of graphene oxide (GO) on the cellular behaviors of C2C12 myoblasts, which were cultured on PLGA decorated with RGD-M13 phage (RGD/PLGA) nanofiber matrices, was investigated. Our results revealed that the RGD/PLGA nanofiber matrices have suitable physicochemical properties as a tissue engineering scaffold and the growth of C2C12 myoblasts were significantly enhanced on the matrices. Moreover, the myogenic differentiation of C2C12 myoblasts was substantially stimulated when they were cultured on the RGD/PLGA matrices in the presence of GO. In conclusion, these findings propose that the combination of RGD/PLGA nanofiber matrices and GO can be used as a promising strategy for skeletal tissue engineering and regeneration.

  10. L6E9 Myoblasts Are Deficient of Myostatin and Additional TGF- Members Are Candidates to Developmentally Control Their Fiber Formation

    Directory of Open Access Journals (Sweden)

    Stefania Rossi

    2010-01-01

    Full Text Available This work provides evidence that the robust myoblast differentiation observed in L6E9 cells is causally linked to deficiency of myostatin, which, conversely, has been found to be expressed in C2C12 cells. However, despite the absence of endogenous myostatin, L6E9 myoblasts expressed functional Activin receptors type II (ActRIIs and follistatin as well as the highly related TGF- members Activins and GDF11, suggesting that in this cell line the regulation of fiber size might be under the control of multiple regulators regardless of myostatin. In line with this hypothesis, delivery of a dominant-negative ActRIIb form or the increase of follistatin, as obtained via Trichostatin treatment or stable transfection of a short human follistatin form, enhanced the L6E9 cell differentiation and further increased the size of myotubes, suggesting that L6E9 myoblasts provide a spontaneous myostatin knock-out in vitro model to study TGF- ligands involved in developmental regulation of fiber size.

  11. Internalization and fate of silica nanoparticles in C2C12 skeletal muscle cells: evidence of a beneficial effect on myoblast fusion.

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    Poussard, Sylvie; Decossas, Marion; Le Bihan, Olivier; Mornet, Stéphane; Naudin, Grégoire; Lambert, Olivier

    2015-01-01

    The use of silica nanoparticles for their cellular uptake capability opens up new fields in biomedical research. Among the toxicological effects associated with their internalization, silica nanoparticles induce apoptosis that has been recently reported as a biochemical cue required for muscle regeneration. To assess whether silica nanoparticles could affect muscle regeneration, we used the C2C12 muscle cell line to study the uptake of fluorescently labeled NPs and their cellular trafficking over a long period. Using inhibitors of endocytosis, we determined that the NP uptake was an energy-dependent process mainly involving macropinocytosis and clathrin-mediated pathway. NPs were eventually clustered in lysosomal structures. Myoblasts containing NPs were capable of differentiation into myotubes, and after 7 days, electron microscopy revealed that the NPs remained primarily within lysosomes. The presence of NPs stimulated the formation of myotubes in a dose-dependent manner. NP internalization induced an increase of apoptotic myoblasts required for myoblast fusion. At noncytotoxic doses, the NP uptake by skeletal muscle cells did not prevent their differentiation into myotubes but, instead, enhanced the cell fusion.

  12. Acute insulin resistance mediated by advanced glycation endproducts in severely burned rats.

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    Zhang, Xing; Xu, Jie; Cai, Xiaoqing; Ji, Lele; Li, Jia; Cao, Bing; Li, Jun; Hu, Dahai; Li, Yan; Wang, Haichang; Xiong, Lize; Xiao, Ruiping; Gao, Feng

    2014-06-01

    Hyperglycemia often occurs in severe burns; however, the underlying mechanisms and importance of managing postburn hyperglycemia are not well recognized. This study was designed to investigate the dynamic changes of postburn hyperglycemia and the underlying mechanisms and to evaluate whether early glycemic control is beneficial in severe burns. Prospective, randomized experimental study. Animal research laboratory. Sprague-Dawley rats. Anesthetized rats were subjected to a full-thickness burn injury comprising 40% of the total body surface area and were randomized to receive vehicle, insulin, and a soluble form of receptor for advanced glycation endproducts treatments. An in vitro study was performed on cultured H9C2 cells subjected to vehicle or carboxymethyllysine treatment. We found that blood glucose change presented a distinct pattern with two occurrences of hyperglycemia at 0.5- and 3-hour postburn, respectively. Acute insulin resistance evidenced by impaired insulin signaling and glucose uptake occurred at 3-hour postburn, which was associated with the second hyperglycemia and positively correlated with mortality. Mechanistically, we found that serum carboxymethyllysine, a dominant species of advanced glycation endproducts, increased within 1-hour postburn, preceding the occurrence of insulin resistance. More importantly, treatment of animals with soluble form of receptor for advanced glycation endproducts, blockade of advanced glycation endproducts signaling, alleviated severe burn-induced insulin resistance. In addition, early hyperglycemic control with insulin not only reduced serum carboxymethyllysine but also blunted postburn insulin resistance and reduced mortality. These findings suggest that severe burn-induced insulin resistance is partly at least mediated by serum advanced glycation endproducts and positively correlated with mortality. Early glycemic control with insulin or inhibition of advanced glycation endproducts with soluble form of receptor

  13. 4,4'-Dichlorodiphenyltrichloroethane (DDT) and 4,4'-dichlorodiphenyldichloroethylene (DDE) inhibit myogenesis in C2C12 myoblasts.

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    Kim, Jonggun; Park, Min Young; Kim, Yoo; Yoon, Kyong Sup; Clark, John Marshall; Park, Yeonhwa; Whang, Kwang-Youn

    2017-12-01

    Most countries have banned the use of 4,4'-dichlorodiphenyltrichloroethane (DDT). However, owing to its extremely high lipophilic characteristics, DDT and its metabolite 4,4'-dichlorodiphenyldichloroethylene (DDE) are ubiquitous in the environment and in many types of food. The positive correlation between exposure to insecticides, including DDT and DDE, and weight gain, resulting in impaired energy metabolism in offspring following perinatal DDT and DDE exposure, was previously reported. Therefore the influence of DDT and DDE on myogenesis using C2C12 myoblasts was investigated in this study. DDT and DDE decreased myotube formation dose- and time-dependently. Among myogenic regulatory factors, DDT and DDE mainly decreased MyoD1 and Myf5 expression. DDT and DDE treatment also altered Myostatin expression, phosphorylation of protein kinase B, p70 ribosomal protein S6 kinase, forkhead box O protein 3 and mammalian target of rapamycin, resulting in attenuation of myotube formation. These results may have significant implications for understanding the effects of developmental exposure of DDT and DDE on myogenesis and development of obesity and type 2 diabetes later in life. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Hybrid Alginate-Protein-Coated Graphene Oxide Microcapsules Enhance the Functionality of Erythropoietin Secreting C2C12 Myoblasts.

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    Saenz Del Burgo, Laura; Ciriza, Jesús; Acarregui, Argia; Gurruchaga, Haritz; Blanco, Francisco Javier; Orive, Gorka; Hernández, Rosa María; Pedraz, Jose Luis

    2017-03-06

    The beneficial effect of combining alginate hydrogel with graphene oxide (GO) on microencapsulated C2C12-myoblast viability has recently been described. However, the commercially available GO lacks homogeneity in size, this parameter being of high relevance for the cell fate in two-dimensional studies. In three-dimensional applications the capacity of this material for binding different kinds of proteins can result in the reduction of de novo released protein that can effectively reach the vicinity of the microcapsules. Undoubtedly, this could be an important hurdle in its clinical use when combined with alginate-PLL microcapsules. Here, we demonstrate that the homogenization of GO nanoparticles is not a mandatory preparation step in order to get the best of this material upon cell microencapsulation. In fact, when the superficial area of these particles is increased, higher amounts of the therapeutic protein erythropoietin (EPO) are adsorbed on their surface. On the other hand, we have been able to improve even more the favorable effects of this graphene derivative on microencapsulated cell viability by forming a protein biocorona. These proteins block the potential binding sites of EPO and, therefore, enhance the amount of therapeutic drug that is released. Finally, we prove that these hybrid alginate-protein-coated GO-microcapsules are functional in vivo.

  15. Necdin enhances myoblasts survival by facilitating the degradation of the mediator of apoptosis CCAR1/CARP1.

    Directory of Open Access Journals (Sweden)

    Stephanie François

    Full Text Available Regeneration of muscle fibers, lost during pathological muscle degeneration or after injuries, is sustained by the production of new myofibers by means of the satellite cells. Survival of the satellite cells is a critical requirement for efficient muscle reconstitution. Necdin, a member of the MAGE proteins family, is expressed in satellite cell-derived myogenic precursors during perinatal growth and in the adult upon activation during muscle regeneration, where it plays an important role both in myoblast differentiation and survival. We show here that necdin exerts its pro-survival activity by counteracting the action of the pro-apoptotic protein Cell Cycle Apoptosis Regulatory Protein (CCAR1/CARP1 that we have identified as a new molecular interactor of necdin by two-hybrid screening. Necdin is responsible for the maintenance of CCAR1 protein levels, by implementing its ubiquitination and degradation through the proteasome. Taken together, these data shed new light on the molecular mechanism of necdin anti-apoptotic activity in myogenesis.

  16. The Dlx5-FGF10 signaling cascade controls cranial neural crest and myoblast interaction during oropharyngeal patterning and development.

    Science.gov (United States)

    Sugii, Hideki; Grimaldi, Alexandre; Li, Jingyuan; Parada, Carolina; Vu-Ho, Thach; Feng, Jifan; Jing, Junjun; Yuan, Yuan; Guo, Yuxing; Maeda, Hidefumi; Chai, Yang

    2017-11-01

    Craniofacial development depends on cell-cell interactions, coordinated cellular movement and differentiation under the control of regulatory gene networks, which include the distal-less (Dlx) gene family. However, the functional significance of Dlx5 in patterning the oropharyngeal region has remained unknown. Here, we show that loss of Dlx5 leads to a shortened soft palate and an absence of the levator veli palatini, palatopharyngeus and palatoglossus muscles that are derived from the 4th pharyngeal arch (PA); however, the tensor veli palatini, derived from the 1st PA, is unaffected. Dlx5-positive cranial neural crest (CNC) cells are in direct contact with myoblasts derived from the pharyngeal mesoderm, and Dlx5 disruption leads to altered proliferation and apoptosis of CNC and muscle progenitor cells. Moreover, the FGF10 pathway is downregulated in Dlx5-/- mice, and activation of FGF10 signaling rescues CNC cell proliferation and myogenic differentiation in these mutant mice. Collectively, our results indicate that Dlx5 plays crucial roles in the patterning of the oropharyngeal region and development of muscles derived from the 4th PA mesoderm in the soft palate, likely via interactions between CNC-derived and myogenic progenitor cells. © 2017. Published by The Company of Biologists Ltd.

  17. Signal mingle: Micropatterns of BMP-2 and fibronectin on soft biopolymeric films regulate myoblast shape and SMAD signaling

    Science.gov (United States)

    Fitzpatrick, Vincent; Fourel, Laure; Destaing, Olivier; Gilde, Flora; Albigès-Rizo, Corinne; Picart, Catherine; Boudou, Thomas

    2017-01-01

    In vivo, bone morphogenetic protein 2 (BMP-2) exists both in solution and bound to the extracellular matrix (ECM). While these two modes of presentation are known to influence cell behavior distinctly, their role in the niche microenvironment and their functional relevance in the genesis of a biological response has sparsely been investigated at a cellular level. Here we used the natural affinity of BMP-2 for fibronectin (FN) to engineer cell-sized micropatterns of BMP-2. This technique allowed the simultaneous control of the spatial presentation of fibronectin-bound BMP-2 and cell spreading. These micropatterns induced a specific actin and adhesion organization around the nucleus, and triggered the phosphorylation and nuclear translocation of SMAD1/5/8 in C2C12 myoblasts and mesenchymal stem cells, an early indicator of their osteoblastic trans-differentiation. We found that cell spreading itself potentiated a BMP-2-dependent phosphorylation of SMAD1/5/8. Finally, we demonstrated that FN/BMP-2-mediated early SMAD signaling depended on LIM kinase 2 and ROCK, rather than myosin II activation. Altogether, our results show that FN/BMP-2 micropatterns are a useful tool to study the mechanisms underlying BMP-2-mediated mechanotransduction. More broadly, our approach could be adapted to other combinations of ECM proteins and growth factors, opening an exciting avenue to recreate tissue-specific niches in vitro.

  18. PI(4,5)P2 regulates myoblast fusion through Arp2/3 regulator localization at the fusion site

    Science.gov (United States)

    Bothe, Ingo; Deng, Su; Baylies, Mary

    2014-01-01

    Cell-cell fusion is a regulated process that requires merging of the opposing membranes and underlying cytoskeletons. However, the integration between membrane and cytoskeleton signaling during fusion is not known. Using Drosophila, we demonstrate that the membrane phosphoinositide PI(4,5)P2 is a crucial regulator of F-actin dynamics during myoblast fusion. PI(4,5)P2 is locally enriched and colocalizes spatially and temporally with the F-actin focus that defines the fusion site. PI(4,5)P2 enrichment depends on receptor engagement but is upstream or parallel to actin remodeling. Regulators of actin branching via Arp2/3 colocalize with PI(4,5)P2 in vivo and bind PI(4,5)P2 in vitro. Manipulation of PI(4,5)P2 availability leads to impaired fusion, with a reduction in the F-actin focus size and altered focus morphology. Mechanistically, the changes in the actin focus are due to a failure in the enrichment of actin regulators at the fusion site. Moreover, improper localization of these regulators hinders expansion of the fusion interface. Thus, PI(4,5)P2 enrichment at the fusion site encodes spatial and temporal information that regulates fusion progression through the localization of activators of actin polymerization. PMID:24821989

  19. Standardized Chinese Formula Xin-Ke-Shu inhibits the myocardium Ca2+ overloading and metabolic alternations in isoproterenol-induced myocardial infarction rats

    Science.gov (United States)

    Liu, Yue-Tao; Zhou, Chao; Jia, Hong-Mei; Chang, Xing; Zou, Zhong-Mei

    2016-01-01

    Xin-Ke-Shu (XKS) is a traditional Chinese patent medicine used for treatment of coronary heart diseases in China. However, its mechanism of action is still unclear. In this paper, the mediation of XKS on the isoproterenol (ISO)-induced myocardial infarction (MI) rat were evaluated based on a tissue-targeted metabonomics in vitro/vivo. The result indicated that twelve metabolic pathways were involved in the therapeutic effect of XKS in vivo, where seven pathways were associated with the Ca2+ overloading mechanism. In agreement with regulation on metabolic variations, XKS markedly reversed the over-expressions of three involved proteins including phospholipase A2 IIA (PLA2 IIA), calcium/calmodulin-dependent protein kinase II (CaMK II) and Pro-Caspase-3. The metabolic regulations of XKS on H9c2 cell also partially confirmed its metabolic effect. These metabolic characteristics in vitro/vivo and western blotting analysis suggested that XKS protected from MI metabolic perturbation major via inhibition of Ca2+ overloading mechanism. Furthermore, 11 active ingredients of XKS exerted steady affinity with the three proteins through the molecular docking study. Our findings indicate that the metabonomics in vitro/vivo combined with western blotting analysis offers the opportunity to gain insight into the comprehensive efficacy of TCMs on the whole metabolic network. PMID:27457884

  20. Neural cell adhesion molecule is a cardioprotective factor up-regulated by metabolic stress.

    Science.gov (United States)

    Nagao, Kazuya; Ono, Koh; Iwanaga, Yoshitaka; Tamaki, Yodo; Kojima, Yoji; Horie, Takahiro; Nishi, Hitoo; Kinoshita, Minako; Kuwabara, Yasuhide; Hasegawa, Koji; Kita, Toru; Kimura, Takeshi

    2010-06-01

    Screening for cell surface proteins up-regulated under stress conditions may lead to the identification of new therapeutic targets. To search for genes whose expression was enhanced by treatment with oligomycin, a mitochondrial-F(0)F(1) ATP synthase inhibitor, signal sequence trapping was performed in H9C2 rat cardiac myoblasts. One of the genes identified was that for neural cell adhesion molecule (NCAM, CD56), a major regulator of development, cell survival, migration, and neurite outgrowth in the nervous system. Immunohistochemical analyses in a mouse myocardial infarction model revealed that NCAM was strongly expressed in residual cardiac myocytes in the infarcted region. Increased expression of NCAM was also found during the remodeling period in a rat model of hypertension-induced heart failure. Lentivirus-mediated knockdown of NCAM decreased the cell growth and survival following oligomycin treatment in H9C2 cells. In primary rat neonatal cardiac myocytes, NCAM was also found to be up-regulated and played a protective role following oligomycin treatment. Analyses of downstream signaling revealed that knockdown of NCAM significantly decreased the basal AKT phosphorylation level. In contrast, NCAM mimetic peptide P2d activated AKT and significantly reduced oligomycin-induced cardiomyocyte death, which was abolished by treatment with the PI3K inhibitor LY-294002 as well as overexpression of the dominant-negative AKT mutant. These findings demonstrate that NCAM is a cardioprotective factor up-regulated under metabolic stress in cardiomyocytes and augmentation of this signal improved survival. (c) 2009 Elsevier Ltd. All rights reserved.

  1. Extracellular creatine regulates creatine transport in rat and human muscle cells.

    OpenAIRE

    Loike, J D; Zalutsky, D L; Kaback, E; Miranda, A F; Silverstein, S C

    1988-01-01

    Muscle cells do not synthesize creatine; they take up exogenous creatine by specific Na+-dependent plasma membrane transporters. We found that extracellular creatine regulates the level of expression of these creatine transporters in L6 rat muscle cells. L6 myoblasts maintained for 24 hr in medium containing 1 mM creatine exhibited 1/3rd of the creatine transport activity of cells maintained for 24 hr in medium without creatine. Down-regulation of creatine transport was partially reversed whe...

  2. Efficient non-viral reprogramming of myoblasts to stemness with a single small molecule to generate cardiac progenitor cells.

    Directory of Open Access Journals (Sweden)

    Zeeshan Pasha

    Full Text Available The current protocols for generation of induced pluripotent stem (iPS cells involve genome integrating viral vectors which may induce tumorgenesis. The aim of this study was to develop and optimize a non-viral method without genetic manipulation for reprogramming of skeletal myoblasts (SMs using small molecules.SMs from young male Oct3/4-GFP(+ transgenic mouse were treated with DNA methyltransferase (DNMT inhibitor, RG108. Two weeks later, GFP(+ colonies of SM derived iPS cells (SiPS expressing GFP and with morphological similarity of mouse embryonic stem (ESCs were formed and propagated in vitro. SiPS were positive for alkaline phosphatase activity, expressed SSEA1, displayed ES cell specific pluripotency markers and formed teratoma in nude mice. Optimization of culture conditions for embryoid body (EBs formation yielded spontaneously contracting EBs having morphological, molecular, and ultra-structural similarities with cardiomyocytes and expressed early and late cardiac markers. miR profiling showed abrogation of let-7 family and upregulation of ESCs specific miR-290-295 cluster thus indicating that SiPS were similar to ESCs in miR profile. Four weeks after transplantation into the immunocompetent mice model of acute myocardial infarction (n = 12 per group, extensive myogenesis was observed in SiPS transplanted hearts as compared to DMEM controls (n = 6 per group. A significant reduction in fibrosis and improvement in global heart function in the hearts transplanted with SiPS derived cardiac progenitor cells were observed.Reprogramming of SMs by DNMT inhibitor is a simple, reproducible and efficient technique more likely to generate transgene integration-free iPS cells. Cardiac progenitors derived from iPS cells propagated extensively in the infarcted myocardium without tumorgenesis and improved cardiac function.

  3. RNA/MBNL1-containing foci in myoblast nuclei from patients affected by myotonic dystrophy type 2: an immunocytochemical study

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    C. Pellicciari

    2009-09-01

    Full Text Available Myotonic dystrophy type 2 (DM2 is a dominantly inherited autosomal disease with multi-systemic clinical features and it is caused by expansion of a CCTG tetranucleotide repeat in the first intron of the zinc finger protein 9 (ZNF9 gene in 3q21.The expanded-CCUG-containing transcripts are retained in the cell nucleus and accumulate in the form of focal aggregates which specifically sequester the muscleblind-like 1 (MBNL1 protein, a RNA binding factor involved in the regulation of alternative splicing. The structural organization and composition of the foci are still incompletely known. In this study, the nuclear foci occurring in cultured myoblasts from DM2 patients were characterised at fluorescence and transmission electron microscopy by using a panel of antibodies recognizing transcription and processing factors of pre-mRNAs. MBNL1 proved to co-locate in the nuclear foci with snRNPs and hnRNPs, whereas no co-location was observed with RNA polymerase II, the non-RNP splicing factor SC35, the cleavage factor CStF and the PML protein. At electron microscopy the MBNL1-containing nuclear foci appeared as roundish domains showing a rather homogeneous structure and proved to contain snRNPs and hnRNPs. The sequestration of splicing factors involved in early phases of pre-mRNA processing supports the hypothesis of a general alteration in the maturation of several mRNAs, which could lead to the multiple pathological dysfunctions observed in dystrophic patients.

  4. Myotube differentiation in clustered regularly interspaced short palindromic repeat/Cas9-mediated MyoD knockout quail myoblast cells

    Directory of Open Access Journals (Sweden)

    Si Won Kim

    2017-07-01

    Full Text Available Objective In the livestock industry, the regulatory mechanisms of muscle proliferation and differentiation can be applied to improve traits such as growth and meat production. We investigated the regulatory pathway of MyoD and its role in muscle differentiation in quail myoblast cells. Methods The MyoD gene was mutated by the clustered regularly interspaced short palindromic repeat (CRISPR/Cas9 technology and single cell-derived MyoD mutant sublines were identified to investigate the global regulatory mechanism responsible for muscle differentiation. Results The mutation efficiency was 73.3% in the mixed population, and from this population we were able to establish two QM7 MyoD knockout subline (MyoD KO QM7#4 through single cell pick-up and expansion. In the undifferentiated condition, paired box 7 expression in MyoD KO QM7#4 cells was not significantly different from regular QM7 (rQM7 cells. During differentiation, however, myotube formation was dramatically repressed in MyoD KO QM7#4 cells. Moreover, myogenic differentiation-specific transcripts and proteins were not expressed in MyoD KO QM7#4 cells even after an extended differentiation period. These results indicate that MyoD is critical for muscle differentiation. Furthermore, we analyzed the global regulatory interactions by RNA sequencing during muscle differentiation. Conclusion With CRISPR/Cas9-mediated genomic editing, single cell-derived sublines with a specific knockout gene can be adapted to various aspects of basic research as well as in functional genomics studies.

  5. Serotonin and Histamine Therapy Increases Tetanic Forces of Myoblasts, Reduces Muscle Injury, and Improves Grip Strength Performance of Dmdmdx Mice

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    Volkan Gurel

    2015-11-01

    Full Text Available Duchenne muscular dystrophy (DMD is a recessive X-linked fatal disorder caused by a mutation in the dystrophin gene. Although several therapeutic approaches have been studied, none has led to substantial long-term effects in patients. The aim of this study was to test a serotonin and histamine (S&H combination on human skeletal myoblasts and Dmdmdx mice for its effects on muscle strength and injury. Normal human bioartificial muscles (BAMs were treated, and muscle tetanic forces and muscle injury tests were performed using the MyoForce Analysis System. Dmdmdx mice, the murine model of DMD, were administered serotonin, histamine, or S&H combination twice daily for 6 weeks, and functional performance tests were conducted once a week. The S&H combination treatment caused significant increases in tetanic forces at all time points and concentrations tested as compared to the saline controls. Dose response of the BAMs to the treatment demonstrated a significant increase in force generation at all concentrations compared to the controls after 3 to 4 days of drug treatment. The highest 3 concentrations had a significant effect on lowering contractile-induced injury as measured by a reduction in the release of adenylate kinase. Histamine-only and S&H treatments improved grip strength of Dmdmdx mice, whereas serotonin-only treatment resulted in no significant improvement in muscle strength. The results of this study indicate that S&H therapy might be a promising new strategy for muscular dystrophies and that the mechanism should be further investigated.

  6. Effective myotube formation in human adipose tissue-derived stem cells expressing dystrophin and myosin heavy chain by cellular fusion with mouse C2C12 myoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Young Woo [Cell Therapy and Tissue Engineering Center, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Biomedical Research Institute, Lifeliver Co., Ltd., Suwon (Korea, Republic of); Lee, Jong Eun; Yang, Mal Sook; Jang, In Keun; Kim, Hyo Eun; Lee, Doo Hoon; Kim, Young Jin [Biomedical Research Institute, Lifeliver Co., Ltd., Suwon (Korea, Republic of); Park, Won Jin [Dr. Park' s Aesthetic Clinic, Seoul (Korea, Republic of); Kong, Jee Hyun; Shim, Kwang Yong [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Lee, Jong In, E-mail: oncochem@yonsei.ac.kr [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of); Kim, Hyun Soo, E-mail: khsmd@unitel.co.kr [Department of Hematology-Oncology, Wonju College of Medicine, Yonsei Univ., Wonju (Korea, Republic of)

    2011-04-29

    Highlights: {yields} hASCs were differentiated into skeletal muscle cells by treatment with 5-azacytidine, FGF-2, and the supernatant of cultured hASCs. {yields} Dystrophin and MyHC were expressed in late differentiation step by treatment with the supernatant of cultured hASCs. {yields} hASCs expressing dystrophin and MyHC contributed to myotube formation during co-culture with mouse myoblast C2C12 cells. -- Abstract: Stem cell therapy for muscular dystrophies requires stem cells that are able to participate in the formation of new muscle fibers. However, the differentiation steps that are the most critical for this process are not clear. We investigated the myogenic phases of human adipose tissue-derived stem cells (hASCs) step by step and the capability of myotube formation according to the differentiation phase by cellular fusion with mouse myoblast C2C12 cells. In hASCs treated with 5-azacytidine and fibroblast growth factor-2 (FGF-2) for 1 day, the early differentiation step to express MyoD and myogenin was induced by FGF-2 treatment for 6 days. Dystrophin and myosin heavy chain (MyHC) expression was induced by hASC conditioned medium in the late differentiation step. Myotubes were observed only in hASCs undergoing the late differentiation step by cellular fusion with C2C12 cells. In contrast, hASCs that were normal or in the early stage were not involved in myotube formation. Our results indicate that stem cells expressing dystrophin and MyHC are more suitable for myotube formation by co-culture with myoblasts than normal or early differentiated stem cells expressing MyoD and myogenin.

  7. Modeling of the human alveolar rhabdomyosarcoma Pax3-Foxo1 chromosome translocation in mouse myoblasts using CRISPR-Cas9 nuclease.

    Directory of Open Access Journals (Sweden)

    Irina V Lagutina

    Full Text Available Many recurrent chromosome translocations in cancer result in the generation of fusion genes that are directly implicated in the tumorigenic process. Precise modeling of the effects of cancer fusion genes in mice has been inaccurate, as constructs of fusion genes often completely or partially lack the correct regulatory sequences. The reciprocal t(2;13(q36.1;q14.1 in human alveolar rhabdomyosarcoma (A-RMS creates a pathognomonic PAX3-FOXO1 fusion gene. In vivo mimicking of this translocation in mice is complicated by the fact that Pax3 and Foxo1 are in opposite orientation on their respective chromosomes, precluding formation of a functional Pax3-Foxo1 fusion via a simple translocation. To circumvent this problem, we irreversibly inverted the orientation of a 4.9 Mb syntenic fragment on chromosome 3, encompassing Foxo1, by using Cre-mediated recombination of two pairs of unrelated oppositely oriented LoxP sites situated at the borders of the syntenic region. We tested if spatial proximity of the Pax3 and Foxo1 loci in myoblasts of mice homozygous for the inversion facilitated Pax3-Foxo1 fusion gene formation upon induction of targeted CRISPR-Cas9 nuclease-induced DNA double strand breaks in Pax3 and Foxo1. Fluorescent in situ hybridization indicated that fore limb myoblasts show a higher frequency of Pax3/Foxo1 co-localization than hind limb myoblasts. Indeed, more fusion genes were generated in fore limb myoblasts via a reciprocal t(1;3, which expressed correctly spliced Pax3-Foxo1 mRNA encoding Pax3-Foxo1 fusion protein. We conclude that locus proximity facilitates chromosome translocation upon induction of DNA double strand breaks. Given that the Pax3-Foxo1 fusion gene will contain all the regulatory sequences necessary for precise regulation of its expression, we propose that CRISPR-Cas9 provides a novel means to faithfully model human diseases caused by chromosome translocation in mice.

  8. Trichocyalides A and B, new inhibitors of alkaline phosphatase activity in bone morphogenetic protein-stimulated myoblasts, produced by Trichoderma sp. FKI-5513.

    Science.gov (United States)

    Fukuda, Takashi; Uchida, Ryuji; Ohte, Satoshi; Inoue, Hiroyo; Yamazaki, Hiroyuki; Matsuda, Daisuke; Nonaka, Kenichi; Masuma, Rokurou; Katagiri, Takenobu; Tomoda, Hiroshi

    2012-11-01

    Two new butenolides, designated trichocyalides A and B, were isolated along with the known compound harzianolide, from the culture broth of Trichoderma sp. FKI-5513 by solvent extraction, ODS column chromatography and HPLC. Their structures were elucidated by several spectral analyses, showing that they have the common skeleton of butenofuranone. Trichocyalides A and B inhibited alkaline phosphatase (ALP) activity, a typical marker enzyme of osteoblastic differentiation (IC(50): 83.0 and 187 μM, respectively), in bone morphogenetic protein (BMP)-stimulated C2C12 myoblasts mutant cells, which stably express BMP receptor activity, whereas harzianolide showed no inhibitory activity against ALP even at 500 μM.

  9. Salvianolic acid A, a novel matrix metalloproteinase-9 inhibitor, prevents cardiac remodeling in spontaneously hypertensive rats.

    Science.gov (United States)

    Jiang, Baohong; Li, Defang; Deng, Yanping; Teng, Fukang; Chen, Jing; Xue, Song; Kong, Xiangqian; Luo, Cheng; Shen, Xu; Jiang, Hualiang; Xu, Feng; Yang, Wengang; Yin, Jun; Wang, Yanhui; Chen, Hui; Wu, Wanying; Liu, Xuan; Guo, De-an

    2013-01-01

    Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted.

  10. α-linolenic acid reduces TNF-induced apoptosis in C2C12 myoblasts by regulating expression of apoptotic proteins

    Directory of Open Access Journals (Sweden)

    Felicia Carotenuto

    2016-11-01

    Full Text Available Impaired regeneration and consequent muscle wasting is a major feature of muscle degenerative diseases. Nutritional interventions as adjuvant strategy for preventing such conditions are recently gaining increasing attention. Ingestion of n3-polyunsaturated fatty acids has been suggested to have a positive impact on muscle diseases. We recently demonstrated that the dietary n3-fatty acid, alpha-linolenic acid (ALA, exerts potent beneficial effects in preserving skeletal muscle regeneration in models of muscle dystrophy. To better elucidate the underlying mechanism we investigate here on the expression level of the anti- and pro-apototic proteins, as well as caspase-3 activity, in C2C12 myoblasts challenged with pathological levels of TNF. The results demonstrated that ALA protective effect on C2C12 myoblasts was associated to an increased Bcl-2/Bax ratio. Indeed, the effect of ALA was directed to rescue Bcl-2 expression and decrease Bax expression both affected in an opposite way by TNF treatment. This effect was associated with a decrease in caspase-3 activity by ALA. TNF is a major pro-inflammatory cytokine that is expressed in damaged skeletal muscle, therefore, counteract inflammatory signals in the muscle microenvironment represents a critical strategy to ameliorate skeletal muscle pathologies

  11. Extremely Low-Frequency Electromagnetic Fields Affect Myogenic Processes in C2C12 Myoblasts: Role of Gap-Junction-Mediated Intercellular Communication

    Directory of Open Access Journals (Sweden)

    Caterina Morabito

    2017-01-01

    Full Text Available Extremely low-frequency electromagnetic fields (ELF-EMFs can interact with biological systems. Although they are successfully used as therapeutic agents in physiatrics and rehabilitative practice, they might represent environmental pollutants and pose a risk to human health. Due to the lack of evidence of their mechanism of action, the effects of ELF-EMFs on differentiation processes in skeletal muscle were investigated. C2C12 myoblasts were exposed to ELF-EMFs generated by a solenoid. The effects of ELF-EMFs on cell viability and on growth and differentiation rates were studied using colorimetric and vital dye assays, cytomorphology, and molecular analysis of MyoD and myogenin expression, respectively. The establishment of functional gap junctions was investigated analyzing connexin 43 expression levels and measuring cell permeability, using microinjection/dye-transfer assays. The ELF-EMFs did not affect C2C12 myoblast viability or proliferation rate. Conversely, at ELF-EMF intensity in the mT range, the myogenic process was accelerated, through increased expression of MyoD, myogenin, and connexin 43. The increase in gap-junction function suggests promoting cell fusion and myotube differentiation. These data provide the first evidence of the mechanism through which ELF-EMFs may provide therapeutic benefits and can resolve, at least in part, some conditions of muscle dysfunction.

  12. Extremely Low-Frequency Electromagnetic Fields Affect Myogenic Processes in C2C12 Myoblasts: Role of Gap-Junction-Mediated Intercellular Communication.

    Science.gov (United States)

    Morabito, Caterina; Steimberg, Nathalie; Rovetta, Francesca; Boniotti, Jennifer; Guarnieri, Simone; Mazzoleni, Giovanna; Mariggiò, Maria A

    2017-01-01

    Extremely low-frequency electromagnetic fields (ELF-EMFs) can interact with biological systems. Although they are successfully used as therapeutic agents in physiatrics and rehabilitative practice, they might represent environmental pollutants and pose a risk to human health. Due to the lack of evidence of their mechanism of action, the effects of ELF-EMFs on differentiation processes in skeletal muscle were investigated. C2C12 myoblasts were exposed to ELF-EMFs generated by a solenoid. The effects of ELF-EMFs on cell viability and on growth and differentiation rates were studied using colorimetric and vital dye assays, cytomorphology, and molecular analysis of MyoD and myogenin expression, respectively. The establishment of functional gap junctions was investigated analyzing connexin 43 expression levels and measuring cell permeability, using microinjection/dye-transfer assays. The ELF-EMFs did not affect C2C12 myoblast viability or proliferation rate. Conversely, at ELF-EMF intensity in the mT range, the myogenic process was accelerated, through increased expression of MyoD, myogenin, and connexin 43. The increase in gap-junction function suggests promoting cell fusion and myotube differentiation. These data provide the first evidence of the mechanism through which ELF-EMFs may provide therapeutic benefits and can resolve, at least in part, some conditions of muscle dysfunction.

  13. The anatomy of the cremaster muscle during inguinoscrotal testicular descent in the rat.

    Science.gov (United States)

    Harnaen, Efrant J; Na, Angelika F; Shenker, Natalie S; Sourial, Magdy; Farmer, Pamela J; Southwell, Bridget R; Hutson, John M

    2007-12-01

    Extrapolation of rat testicular descent studies to humans has been criticized because of anatomical differences of the cremaster muscle. Human cremaster is described as a thin strip rather than a large, complete sac as in rats, which is proposed to be more important in propelling the testis during descent. This study investigated cremaster muscle anatomy and ontogeny in both normal and cryptorchid rat models. Gubernacula from 4 groups of neonatal rats were sectioned longitudinally and transversely: normal Sprague-Dawley, capsaicin pretreated, flutamide pretreated, and congenital cryptorchid rats. Gubernacula were stained with hematoxylin-eosin, Masson trichrome, and desmin immunohistochemistry to study muscle development. Myoblasts are more numerous at the gubernacular tip, whereas the most differentiated muscle is proximal. Rat cremaster develops as an elongated strip rather than a complete sac derived from abdominal wall muscles. Flutamide and capsaicin pretreatment disrupts development. Rat cremaster muscle develops as a strip, bearing close resemblance to human cremaster muscle, permitting extrapolation of cremaster function to human testicular descent. The cremaster muscle appears to differentiate from the gubernacular tip during elongation to the scrotum, and requires intact sensory innervation and androgen.

  14. Cultured senescent myoblasts derived from human vastus lateralis exhibit normal mitochondrial ATP synthesis capacities with correlating concomitant ROS production while whole cell ATP production is decreased

    DEFF Research Database (Denmark)

    Minet, Ariane D; Gaster, Michael

    2012-01-01

    satellite cells at early and late passage numbers. We show that cultured muscle satellite cells undergoing senescence express a reduced mitochondrial mass, decreased whole cell ATP level, normal to increased mitochondrial ATP production under ATP utilization, increased mitochondrial membrane potential......The free radical theory of aging says that increased oxidative stress and mitochondrial dysfunction are associated with old age. In the present study we have investigated the effects of cellular senescence on muscle energetic by comparing mitochondrial content and function in cultured muscle...... and increased superoxide/mitochondrial mass and hydrogen peroxide/mitochondrial mass ratios. Moreover, the increased ROS production correlates with the corresponding mitochondrial ATP production. Thus, myotubes differentiated from human myoblasts undergoing senescence have a reduced mitochondrial content...

  15. MicroRNA, miR-374b, directly targets Myf6 and negatively regulates C2C12 myoblasts differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhiyuan; Sun, Xiaorui; Xu, Dequan; Xiong, Yuanzhu; Zuo, Bo, E-mail: zuobo@mail.hzau.edu.cn

    2015-11-27

    Myogenesis is a complex process including myoblast proliferation, differentiation and myotube formation and is controlled by myogenic regulatory factors (MRFs), MyoD, MyoG, Myf5 and Myf6 (also known as MRF4). MicroRNA is a kind of ∼22 nt-long non-coding small RNAs, and act as key transcriptional or post-transcriptional regulators of gene expression. Identification of miRNAs involved in the regulation of muscle genes could improve our understanding of myogenesis process. In this study, we investigated the regulation of Myf6 gene by miRNAs. We showed that miR-374b specifically bound to the 3'untranslated region (UTR) of Myf6 and down-regulated the expression of Myf6 gene at both mRNA and protein level. Furthermore, miR-374b is ubiquitously expressed in the tissues of adult C57BL6 mouse, and the mRNA abundance increases first and then decreases during C2C12 myoblasts differentiation. Over-expression of miR-374b impaired C2C12 cell differentiation, while inhibiting miR-374b expression by 2′-O-methyl antisense oligonucleotides promoted C2C12 cell differentiation. Taken together, our findings identified miR-374b directly targets Myf6 and negatively regulates myogenesis. - Highlights: • MiR-374b directly targets 3′UTR of Myf6. • MiR-374b negatively regulates Myf6 in C2C12 cells. • MiR-374b abundance significiently changes during C2C12 cells differentiation. • MiR-374b negatively regulates C2C12 cells differentiation.

  16. Hybrid Randomly Electrospun Poly(lactic-co-glycolic acid):Poly(ethylene oxide) (PLGA:PEO) Fibrous Scaffolds Enhancing Myoblast Differentiation and Alignment.

    Science.gov (United States)

    Evrova, Olivera; Hosseini, Vahid; Milleret, Vincent; Palazzolo, Gemma; Zenobi-Wong, Marcy; Sulser, Tullio; Buschmann, Johanna; Eberli, Daniel

    2016-11-23

    Cellular responses are regulated by their microenvironments, and engineered synthetic scaffolds can offer control over different microenvironment properties. This important relationship can be used as a tool to manipulate cell fate and cell responses for different biomedical applications. We show for the first time in this study how blending of poly(ethylene oxide) (PEO) to poly(lactic-co-glycolic acid) (PLGA) fibers to yield hybrid scaffolds changes the physical and mechanical properties of PLGA fibrous scaffolds and in turn affects cellular response. For this purpose we employed electrospinning to create fibrous scaffolds mimicking the basic structural properties of the native extracellular matrix. We introduced PEO to PLGA electrospun fibers by spinning a blend of PLGA:PEO polymer solutions in different ratios. PEO served as a sacrificial component within the fibers upon hydration, leading to pore formation in the fibers, fiber twisting, increased scaffold disintegration, and hydrophilicity, decreased Young's modulus, and significantly improved strain at break of initially electrospun scaffolds. We observed that the blended PLGA:PEO fibrous scaffolds supported myoblast adhesion and proliferation and resulted in increased myotube formation and self-alignment, when compared to PLGA-only scaffolds, even though the scaffolds were randomly oriented. The 50:50 PLGA:PEO blended scaffold showed the most promising results in terms of mechanical properties, myotube formation, and alignment, suggesting an optimal microenvironment for myoblast differentiation from the PLGA:PEO blends tested. The explored approach for tuning fiber properties can easily extend to other polymeric scaffolds and provides a valuable tool to engineer fibrillar microenvironments for several biomedical applications.

  17. Cell-Adhesive Matrices Composed of RGD Peptide-Displaying M13 Bacteriophage/Poly(lactic-co-glycolic acid) Nanofibers Beneficial to Myoblast Differentiation.

    Science.gov (United States)

    Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Kim, Chuntae; Hong, Suck Won; Oh, Jin Woo; Han, Dong-Wook

    2015-10-01

    Recently, there has been considerable effort to develop suitable scaffolds for tissue engineering applications. Cell adhesion is a prerequisite for cells to survive. In nature, the extracellular matrix (ECM) plays this role. Therefore, an ideal scaffold should be structurally similar to the natural ECM and have biocompatibility and biodegradability. In addition, the scaffold should have biofunctionality, which provides the potent ability to enhance the cellular behaviors, such as adhesion, proliferation and differentiation. This study concentrates on fabricating cell-adhesive matrices composed of RGD peptide-displaying M13 bacteriophage (RGD-M13 phage) and poly(lactic-co-glycolic acid, PLGA) nanofibers. Long rod-shaped M13 bacteriophages are non-toxic and can express many desired proteins on their surface. A genetically engineered M13 phage was constructed to display RGD peptides on its surface. PLGA is a biodegradable polymer with excellent biocompatibility and suitable physicochemical property for adhesive matrices. In this study, RGD-M13 phage/PLGA hybrid nanofiber matrices were fabricated by electrospinning. The physicochemical properties of these matrices were characterized by scanning electron microscopy, atomic force microscopy, Raman spectroscopy, and contact angle measurement. In addition, the cellular behaviors, such as the initial attachment, proliferation and differentiation, were analyzed by a CCK-8 assay and immunofluorescence staining to evaluate the potential application of these matrices to tissue engineering scaffolds. The RGD-M13 phage/PLGA nanofiber matrices could enhance the cellular behaviors and promote the differentiation of C2C12 myoblasts. These results suggest that the RGD-M13 phage/PLGA nanofiber matrices are beneficial to myoblast differentiation and can serve as effective tissue engineering scaffolds.

  18. The protective effects of silybin on the cytotoxicity of thiram in human, rat and chicken cell cultures.

    Science.gov (United States)

    Radko, Lidia; Cybulski, Wojciech; Rzeski, Wojciech

    2017-11-01

    The study objective was a determination of thiram cytotoxicity and silybin cytoprotective activity in course of the fungicide impact on cell metabolism and membrane integrity. Firstly, human, rat, chicken hepatoma cells and rat myoblasts cultures were incubated with thiram. The results showed higher sensitivity of myoblasts on thiram exposure than the hepatoma cells. Among hepatoma cells, the chicken cultures were the most sensitive on the fungicide endangering. The mitochondrial activity was the most thiram affected function within all types the cell lines used. When silybin co-acted with thiram, an increase of the cell viability was recorded. The EC50-values were higher for thiram subjected to interaction with silybin than the effect of alone thiram action. The interaction mode between the studied compounds shown by combination index (CI) represented an antagonistic or an additive nature and was depended on thiram concentration, type of the cells and the assay used. Moreover, the morphology changes were dependent on silybin presence in the cell cultures subjected to thiram impact at the same time. Staining with Hoechst 33342 and propidium ioidium revealed the apoptosis cell death in the incubation cultures. Definitely, the results have shown a potential of silybin to protect the cultured cells in course of cytotoxicity induced by thiram. However, future studies taking into account other endpoints of thiram cytotoxicity pathways including species differences and the cytoprotection efficacy could be of interest. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The cardioprotective effect of melatonin and exendin-4 treatment in a rat model of cardiorenal syndrome.

    Science.gov (United States)

    Chua, Sarah; Lee, Fan-Yen; Chiang, Hsin-Ju; Chen, Kuan-Hung; Lu, Hung-I; Chen, Yen-Ta; Yang, Chih-Chao; Lin, Kun-Chen; Chen, Yi-Ling; Kao, Gour-Shenq; Chen, Chih-Hung; Chang, Hsueh-Wen; Yip, Hon-Kan

    2016-11-01

    We investigated the cardioprotective effect of melatonin (Mel) and exendin-4 (Ex4) treatment in a rat model of cardiorenal syndrome (CRS). Adult male SD rats (n=48) were randomly and equally divided into sham control (SC), dilated cardiomyopathy (DCM) (doxorubicin 7 mg/kg i.p. every five days/4 doses), CRS (defined as DCM+CKD) only, CRS-Mel (20 mg/kg/d), CRS-Ex4 (10 μg/kg/d), and CRS-Mel-Ex4 groups. In vitro results showed protein expressions of oxidative stress (NOX-1/NOX-2/oxidized protein), DNA/mitochondrial damage (γ-H2AX/cytosolic cytochrome c), apoptosis (cleaved caspase-3/PARP), and senescence (β-galactosidase cells) biomarkers were upregulated, whereas mitochondrial ATP level was decreased in doxorubicin/p-cresol-treated H9c2 cells that were revised by Mel and Ex4 treatments (all P<.001). By day 60, LVEF was highest in the SC and lowest in the CRS, significantly lower in the DCM than in other treatment groups, lower in the CRS-Mel and CRS-Ex4 than in the CRS-Mel-Ex4, and lower in the CRS-Mel than in the CRS-Ex4, whereas LV chamber size and histopathology score showed a pattern opposite to that of LVEF among all groups (all P<.001). Plasma creatinine level was highest in the CRS and lowest in the SC and progressively decreased from the CRS-Mel, CRS-Ex4, CRS-Mel-Ex4 to DCM (P<.0001). Protein expressions of inflammation (TNF-α/NF-κB/MMP-2/MMP-9/IL-1β), apoptosis/DNA damage (Bax/c-caspase-3/c-PARP/γ-H2AX), fibrosis (Smad3/TGF-β), oxidative stress (NOX-1/NOX-2/NOX-4/oxidized protein), cardiac hypertrophy/pressure overload (BNP/β-MHC), and cardiac integrity (Cx43/α-MHC) biomarkers in LV myocardium showed an opposite pattern compared to that of LVEF among all groups (all P<.001). Fibrotic area, DNA damage (γ-H2AX(+) /53BP1(+) CD90(+) /XRCC1(+) CD90(+) ), and inflammation (CD14(+) /CD68(+) ) biomarkers in LV myocardium displayed a pattern opposite to that of LVEF among all groups (all P<.001). Combined melatonin and exendin-4 treatment suppressed CRS

  20. The inhibition of cultured myoblast differentiation by the simian virus 40 large T antigen occurs after myogenin expression and Rb up-regulation and is not exerted by transformation-competent cytoplasmic mutants.

    OpenAIRE

    Tedesco, D; Caruso, M; Fischer-Fantuzzi, L; Vesco, C

    1995-01-01

    We have investigated the mechanism by which the simian virus 40 large T antigen (SVLT) interferes with the differentiation of C2 myoblasts. SVLT mutants, defective either in the Rb binding site, near the N-terminal end, in a region that affects binding to p53, or in the nuclear transport signal, were also employed to determine whether the interference was especially dependent on these functional domains. It was found that wild-type (wt) SVLT strongly inhibited the terminal differentiation of ...

  1. Induction of cyclins E and A in response to mitogen removal: a basic alteration associated with the arrest of differentiation of C2 myoblasts transformed by simian virus 40 large T antigen.

    OpenAIRE

    Tedesco, D; Baron, L; Fischer-Fantuzzi, L; Vesco, C

    1997-01-01

    We previously showed that C2 myoblasts transformed by simian virus 40 large T antigen (SVLT) stop the myogenic process after the induction of myogenin and of high Rb levels; the induced Rb, however, becomes notably phosphorylated. We have analyzed the protein levels and activities of cyclin-dependent kinases (cdks) in untransformed C2 cells and in transformants of either SVLT or the cytoplasmic mutant NKT1 (which permits differentiation) upon a shift from growth medium (GM) to mitogen-poor di...

  2. Sodium arsenite represses the expression of myogenin in C2C12 mouse myoblast cells through histone modifications and altered expression of Ezh2, Glp, and Igf-1

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gia-Ming [Environmental Toxicology Graduate Program, Clemson University, 132 Long Hall, Clemson, SC 29634 (United States); Present address: The University of Chicago, Section of Hematology/Oncology, 900 E. 57th Street, Room 7134, Chicago, IL 60637 (United States); Bain, Lisa J., E-mail: lbain@clemson.edu [Environmental Toxicology Graduate Program, Clemson University, 132 Long Hall, Clemson, SC 29634 (United States); Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634 (United States)

    2012-05-01

    Arsenic is a toxicant commonly found in water systems and chronic exposure can result in adverse developmental effects including increased neonatal death, stillbirths, and miscarriages, low birth weight, and altered locomotor activity. Previous studies indicate that 20 nM sodium arsenite exposure to C2C12 mouse myocyte cells delayed myoblast differentiation due to reduced myogenin expression, the transcription factor that differentiates myoblasts into myotubes. In this study, several mechanisms by which arsenic could alter myogenin expression were examined. Exposing differentiating C2C12 cells to 20 nM arsenic increased H3K9 dimethylation (H3K9me2) and H3K9 trimethylation (H3K9me3) by 3-fold near the transcription start site of myogenin, which is indicative of increased repressive marks, and reduced H3K9 acetylation (H3K9Ac) by 0.5-fold, indicative of reduced permissive marks. Protein expression of Glp or Ehmt1, a H3-K9 methyltransferase, was also increased by 1.6-fold in arsenic-exposed cells. In addition to the altered histone remodeling status on the myogenin promoter, protein and mRNA levels of Igf-1, a myogenic growth factor, were significantly repressed by arsenic exposure. Moreover, a 2-fold induction of Ezh2 expression, and an increased recruitment of Ezh2 (3.3-fold) and Dnmt3a (∼ 2-fold) to the myogenin promoter at the transcription start site (− 40 to + 42), were detected in the arsenic-treated cells. Together, we conclude that the repressed myogenin expression in arsenic-exposed C2C12 cells was likely due to a combination of reduced expression of Igf-1, enhanced nuclear expression and promoter recruitment of Ezh2, and altered histone remodeling status on myogenin promoter (− 40 to + 42). -- Highlights: ► Igf-1 expression is decreased in C2C12 cells after 20 nM arsenite exposure. ► Arsenic exposure alters histone remodeling on the myogenin promoter. ► Glp expression, a H3–K9 methyltransferase, was increased in arsenic-exposed cells. ► Ezh2

  3. Echinochrome A Protects Mitochondrial Function in Cardiomyocytes against Cardiotoxic Drugs

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    Seung Hun Jeong

    2014-05-01

    Full Text Available Echinochrome A (Ech A is a naphthoquinoid pigment from sea urchins that possesses antioxidant, antimicrobial, anti-inflammatory and chelating abilities. Although Ech A is the active substance in the ophthalmic and cardiac drug Histochrome®, its underlying cardioprotective mechanisms are not well understood. In this study, we investigated the protective role of Ech A against toxic agents that induce death of rat cardiac myoblast H9c2 cells and isolated rat cardiomyocytes. We found that the cardiotoxic agents tert-Butyl hydroperoxide (tBHP, organic reactive oxygen species (ROS inducer, sodium nitroprusside (SNP; anti-hypertension drug, and doxorubicin (anti-cancer drug caused mitochondrial dysfunction such as increased ROS level and decreased mitochondrial membrane potential. Co-treatment with Ech A, however, prevented this decrease in membrane potential and increase in ROS level. Co-treatment of Ech A also reduced the effects of these cardiotoxic agents on mitochondrial oxidative phosphorylation and adenosine triphosphate level. These findings indicate the therapeutic potential of Ech A for reducing cardiotoxic agent-induced damage.

  4. Development and Growth of the Avian Pectoralis Major (Breast Muscle: Function of Syndecan-4 and Glypican-1 in Adult Myoblast Proliferation and Differentiation

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    Sandra G. Velleman

    2017-08-01

    Full Text Available Muscle fiber number is determined around the time hatch with continued posthatch muscle growth being mediated by the adult myoblast, satellite cell, population of cells. Satellite cells are dynamic in their expression of proteins including the cell membrane associated proteoglycans, syndecan-4 and glypican-1. These proteoglycans play roles in organizing the extracellular environment in the satellite cell niche, cytoskeletal structure, cell-to-cell adhesion, satellite cell migration, and signal transduction. This review article focuses on syndecan-4 and glypican-1 as both are capable of regulating satellite cell responsiveness to fibroblast growth factor 2. Fibroblast growth factor 2 is a potent stimulator of muscle cell proliferation and a strong inhibitor of differentiation. Proteoglycans are composed of a central core protein defined functional domains, and covalently attached glycosaminoglycans and N-glycosylation chains. The functional association of these components with satellite cell function is discussed as well as an emerging role for microRNA regulation of syndecan-4 and glypican-1.

  5. PEO-PPO Diblock Copolymers Protect Myoblasts from Hypo-Osmotic Stress In Vitro Dependent on Copolymer Size, Composition, and Architecture.

    Science.gov (United States)

    Kim, Mihee; Haman, Karen J; Houang, Evelyne M; Zhang, Wenjia; Yannopoulos, Demetris; Metzger, Joseph M; Bates, Frank S; Hackel, Benjamin J

    2017-07-10

    Poloxamer 188, a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), protects cellular membranes from various stresses. Though numerous block copolymer variants exist, evaluation of alternative architecture, composition, and size has been minimal. Herein, cultured murine myoblasts are exposed to the stresses of hypotonic shock and isotonic recovery, and membrane integrity was evaluated by quantifying release of lactate dehydrogenase. Comparative evaluation of a systematic set of PEO-PPO diblock and PEO-PPO-PEO triblock copolymers demonstrates that the diblock architecture can be protective in vitro. Short PPO blocks hinder protection with >9 PPO units needed for protection at 150 μM and >16 units needed at 14 μM. Addition of a tert-butyl end group enhances protection at reduced concentration. When the end group and PPO length are fixed, increasing the PEO length improves protection. This systematic evaluation establishes a new in vitro screening tool for evaluating membrane-sealing amphiphiles and provides mechanistic insight to guide future copolymer design for membrane stabilization in vivo.

  6. In Situ Real-Time Chemiluminescence Imaging of Reactive Oxygen Species Formation from Cardiomyocytes

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    Yunbo Li

    2008-01-01

    Full Text Available We have applied the highly sensitive chemiluminescence (CL imaging technique to investigate the in situ ROS formation in cultured monolayers of rat H9c2 cardiomyocytes. Photon emission was detected via an innovative imaging system after incubation of H9c2 cells in culture with luminol and horseradish peroxidase (HRP, suggesting constitutive formation of ROS by the cardiomyocytes. Addition of benzo(apyrene-1,6-quinone (BPQ to cultured H9c2 cells resulted in a 4-5-fold increase in the formation of ROS, as detected by the CL imaging. Both constitutive and BPQ-stimulated CL responses in cultured H9c2 cells were sustained for up to 1 hour. The CL responses were completely abolished in the presence of superoxide dismutase and catalase, suggesting the primary involvement of superoxide and hydrogen peroxide (H2O2. In contrast to BPQ-mediated redox cycling, blockage of mitochondrial electron transport chain by either antimycin A or rotenone exerted marginal effects on the ROS formation by cultured H9c2 cells. Upregulation of cellular antioxidants for detoxifying both superoxide and H2O2 by 3H-1,2-dithiole-3-thione resulted in marked inhibition of both constitutive and BPQ-augmented ROS formation in cultured H9c2 cells. Taken together, we demonstrate the sensitive detection of ROS by CL imaging in cultured cardiomyocytes.

  7. Ethanol extract of Prunus mume fruit attenuates hydrogen peroxide-induced oxidative stress and apoptosis involving Nrf2/HO-1 activation in C2C12 myoblasts

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    Ji Sook Kang

    Full Text Available ABSTRACT The fruit of the Prunus mume (Siebold Siebold & Zucc., Rosaceae (Korean name: Maesil has long been used as a health food or valuable medicinal material in traditional herb medicine in Southeast Asian countries. In this study, we determined the potential therapeutic efficacy of the ethanol extract of P. mume fruits (EEPM against H2O2-induced oxidative stress and apoptosis in the murine skeletal muscle myoblast cell line C2C12, and sought to understand the associated molecular mechanisms. The results indicated that exposure of C2C12 cells to H2O2 caused a reduction in cell viability by increasing the generation of intracellular reactive oxygen species and by disrupting mitochondrial membrane permeability, leading to DNA damage and apoptosis. However, pretreatment of the cells with EEPM before H2O2 exposure effectively attenuated these changes, suggesting that EEPM prevented H2O2-induced mitochondria-dependent apoptosis. Furthermore, the increased ex-pression and phosphorylation of nuclear factor erythroid 2-related factor 2 (Nrf2 and up-regulation of heme oxygenase-1 (HO-1, a phase II antioxidant enzyme, were detected in EEPM-treated C2C12 cells. We also found that zinc protoporphyrin IX, an HO-1 inhibitor, attenuated the protective effects of EEPM against H2O2-induced reactive oxygen species accumulation and cytotoxicity. Therefore, these results indicate that the activation of the Nrf2/HO-1 pathway might be involved in the protection of EEPM against H2O2-induced cellular oxidative damage. In conclusion, these results show that EEPM contributes to the prevention of oxidative damage and could be used as a nutritional agent for oxidative stress-related diseases.

  8. Serotonin and Histamine Therapy Increases Tetanic Forces of Myoblasts, Reduces Muscle Injury, and Improves Grip Strength Performance of Dmd(mdx) Mice.

    Science.gov (United States)

    Gurel, Volkan; Lins, Jeremy; Lambert, Kristyn; Lazauski, Joan; Spaulding, James; McMichael, John

    2015-01-01

    Duchenne muscular dystrophy (DMD) is a recessive X-linked fatal disorder caused by a mutation in the dystrophin gene. Although several therapeutic approaches have been studied, none has led to substantial long-term effects in patients. The aim of this study was to test a serotonin and histamine (S&H) combination on human skeletal myoblasts and Dmd(mdx) mice for its effects on muscle strength and injury. Normal human bioartificial muscles (BAMs) were treated, and muscle tetanic forces and muscle injury tests were performed using the MyoForce Analysis System. Dmd(mdx) mice, the murine model of DMD, were administered serotonin, histamine, or S&H combination twice daily for 6 weeks, and functional performance tests were conducted once a week. The S&H combination treatment caused significant increases in tetanic forces at all time points and concentrations tested as compared to the saline controls. Dose response of the BAMs to the treatment demonstrated a significant increase in force generation at all concentrations compared to the controls after 3 to 4 days of drug treatment. The highest 3 concentrations had a significant effect on lowering contractile-induced injury as measured by a reduction in the release of adenylate kinase. Histamine-only and S&H treatments improved grip strength of Dmd(mdx) mice, whereas serotonin-only treatment resulted in no significant improvement in muscle strength. The results of this study indicate that S&H therapy might be a promising new strategy for muscular dystrophies and that the mechanism should be further investigated.

  9. Retinoid acid-induced microRNA-27b-3p impairs C2C12 myoblast proliferation and differentiation by suppressing α-dystrobrevin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan; Tang, Yi; Liu, Bo; Cong, Wei; Liu, Chao, E-mail: liuchao_19760711@yahoo.com; Xiao, Jing, E-mail: xiaoj@dmu.edu.cn

    2017-01-15

    We previously reported that excess retinoic acid (RA) resulted in hypoplastic and derangement of myofilaments in embryonic tongue by inhibiting myogenic proliferation and differentiation through CamKIID pathway. Our further studies revealed that the expression of a series of miRNAs was altered by RA administration in embryonic tongue as well as in C2C12 cells. Thus, if excess RA impairs myogenic proliferation and differentiation through miRNAs is taken into account. In present study, miR-27b-3p was found up-regulated in RA-treated C2C12 cells as in embryonic tongue, and predicted to target the 3′UTR of α-dystrobrevin (DTNA). Luciferase reporter assays confirmed the direct interaction between miR-27b-3p and the 3′UTR of DTNA. MiR-27b-3p mimics recapitulated the RA repression on DTNA expression, C2C12 proliferation and differentiation, while the miR-27b-3p inhibitor circumvented these defects resulting from excess RA. As expected, the effects of siDTNA on C2C12 were coincided with those by RA treatment or miR-27b-3p mimics. Therefore, these findings indicated that excess RA inhibited the myoblast proliferation and differentiation by up-regulating miR-27b-3p to target DTNA, which implied a new mechanism in myogenic hypoplasia. - Highlights: • A mechanism that RA results in tongue deformity by disrupting the myogenesis. • A non-muscle specific miR mediating the RA suppression on tongue myogenesis. • A target gene of non-muscle specific miR involved in RA induced tongue deformity.

  10. Transforming growth factor type-β inhibits Mas receptor expression in fibroblasts but not in myoblasts or differentiated myotubes; Relevance to fibrosis associated to muscular dystrophies.

    Science.gov (United States)

    Cofre, Catalina; Acuña, María José; Contreras, Osvaldo; Morales, María Gabriela; Riquelme, Cecilia; Cabello-Verrugio, Claudio; Brandan, Enrique

    2015-01-01

    Duchenne muscular dystrophy is a genetic disorder characterized by myofiber degeneration, muscle weakness, and increased fibrosis. Transforming growth factor type-β (TGF-β), a central mediator of fibrosis, is upregulated in fibrotic diseases. Angiotensin-(1-7) [Ang-(1-7)] is a peptide with actions that oppose those of angiotensin-II (Ang II). Ang-(1-7) effects are mediated by the Mas receptor. Treatment with Ang-(1-7) produce positive effects in the mdx mouse, normalizing skeletal muscle architecture, decreasing local fibrosis, and fibroblasts, and improving muscle function. Mdx mice deficient for the Mas receptor showed the opposite effects. To identify the cell type(s) responsible for Mas receptor expression, and to characterize whether profibrotic effectors had any effect on its expression, we determined the effect of profibrotic agents on Mas expression. TGF-β, but not connective tissue growth factor or Ang-II, reduced the expression of Mas receptor in fibroblasts isolated from skeletal muscle cells and fibroblasts from two established cell lines. In contrast, no effects were observed in myoblasts and differentiated myotubes. This inhibition was mediated by the Smad-dependent (canonical) and the PI3K and MEK1/2 (noncanonical) TGF-β signaling pathways. When both canonical and noncanonical inhibitors of the TGF-β-dependent pathways were added together, the inhibitory effect of TGF-β on Mas expression was lost. The decrease in Mas receptor induced by TGF-β in fibroblasts reduced the Ang-(1-7) mediated stimulation of phosphorylation of AKT pathway proteins. These results suggest that reduction of Mas receptor in fibroblasts, by TGF-β, could increase the fibrotic phenotype observed in dystrophic skeletal muscle decreasing the beneficial effect of Ang-(1-7). © 2015 International Union of Biochemistry and Molecular Biology.

  11. Global N-linked Glycosylation is Not Significantly Impaired in Myoblasts in Congenital Myasthenic Syndromes Caused by Defective Glutamine-Fructose-6-Phosphate Transaminase 1 (GFPT1

    Directory of Open Access Journals (Sweden)

    Qiushi Chen

    2015-10-01

    Full Text Available Glutamine-fructose-6-phosphate transaminase 1 (GFPT1 is the first enzyme of the hexosamine biosynthetic pathway. It transfers an amino group from glutamine to fructose-6-phosphate to yield glucosamine-6-phosphate, thus providing the precursor for uridine diphosphate N-acetylglucosamine (UDP-GlcNAc synthesis. UDP-GlcNAc is an essential substrate for all mammalian glycosylation biosynthetic pathways and N-glycan branching is especially sensitive to alterations in the concentration of this sugar nucleotide. It has been reported that GFPT1 mutations lead to a distinct sub-class of congenital myasthenic syndromes (CMS termed “limb-girdle CMS with tubular aggregates”. CMS are hereditary neuromuscular transmission disorders in which neuromuscular junctions are impaired. To investigate whether alterations in protein glycosylation at the neuromuscular junction might be involved in this impairment, we have employed mass spectrometric strategies to study the N-glycomes of myoblasts and myotubes derived from two healthy controls, three GFPT1 patients, and four patients with other muscular diseases, namely CMS caused by mutations in DOK7, myopathy caused by mutations in MTND5, limb girdle muscular dystrophy type 2A (LGMD2A, and Pompe disease. A comparison of the relative abundances of bi-, tri-, and tetra-antennary N-glycans in each of the cell preparations revealed that all samples exhibited broadly similar levels of branching. Moreover, although some differences were observed in the relative abundances of some of the N-glycan constituents, these variations were modest and were not confined to the GFPT1 samples. Therefore, GFPT1 mutations in CMS patients do not appear to compromise global N-glycosylation in muscle cells.

  12. G-protein coupled receptor 56 promotes myoblast fusion through serum response factor- and nuclear factor of activated T-cell-mediated signalling but is not essential for muscle development in vivo.

    Science.gov (United States)

    Wu, Melissa P; Doyle, Jamie R; Barry, Brenda; Beauvais, Ariane; Rozkalne, Anete; Piao, Xianhua; Lawlor, Michael W; Kopin, Alan S; Walsh, Christopher A; Gussoni, Emanuela

    2013-12-01

    Mammalian muscle cell differentiation is a complex process of multiple steps for which many of the factors involved have not yet been defined. In a screen to identify the regulators of myogenic cell fusion, we found that the gene for G-protein coupled receptor 56 (GPR56) was transiently up-regulated during the early fusion of human myoblasts. Human mutations in the gene for GPR56 cause the disease bilateral frontoparietal polymicrogyria; however, the consequences of receptor dysfunction on muscle development have not been explored. Using knockout mice, we defined the role of GPR56 in skeletal muscle. GPR56(-/-) myoblasts have decreased fusion and smaller myotube sizes in culture. In addition, a loss of GPR56 expression in muscle cells results in decreases or delays in the expression of myogenic differentiation 1, myogenin and nuclear factor of activated T-cell (NFAT)c2. Our data suggest that these abnormalities result from decreased GPR56-mediated serum response element and NFAT signalling. Despite these changes, no overt differences in phenotype were identified in the muscle of GPR56 knockout mice, which presented only a mild but statistically significant elevation of serum creatine kinase compared to wild-type. In agreement with these findings, clinical data from 13 bilateral frontoparietal polymicrogyria patients revealed mild serum creatine kinase increase in only two patients. In summary, targeted disruption of GPR56 in mice results in myoblast abnormalities. The absence of a severe muscle phenotype in GPR56 knockout mice and human patients suggests that other factors may compensate for the lack of this G-protein coupled receptor during muscle development and that the motor delay observed in these patients is likely not a result of primary muscle abnormalities. © 2013 FEBS.

  13. Assessing bacterial invasion of cardiac cells in culture and heart colonization in infected mice using Listeria monocytogenes.

    Science.gov (United States)

    McMullen, P David; Freitag, Nancy E

    2015-05-27

    Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that is capable of causing serious invasive infections in immunocompromised patients, the elderly, and pregnant women. The most common manifestations of listeriosis in humans include meningitis, encephalitis, and fetal abortion. A significant but much less documented sequelae of invasive L. monocytogenes infection involves the heart. The death rate from cardiac illness can be up to 35% despite treatment, however very little is known regarding L. monocytogenes colonization of cardiac tissue and its resultant pathologies. In addition, it has recently become apparent that subpopulations of L. monocytogenes have an enhanced capacity to invade and grow within cardiac tissue. This protocol describes in detail in vitro and in vivo methods that can be used for assessing cardiotropism of L. monocytogenes isolates. Methods are presented for the infection of H9c2 rat cardiac myoblasts in tissue culture as well as for the determination of bacterial colonization of the hearts of infected mice. These methods are useful not only for identifying strains with the potential to colonize cardiac tissue in infected animals, but may also facilitate the identification of bacterial gene products that serve to enhance cardiac cell invasion and/or drive changes in heart pathology. These methods also provide for the direct comparison of cardiotropism between multiple L. monocytogenes strains.

  14. Azidothymidine-triphosphate impairs mitochondrial dynamics by disrupting the quality control system

    Directory of Open Access Journals (Sweden)

    Ryosuke Nomura

    2017-10-01

    Full Text Available Highly active anti-retrovirus therapy (HAART has been used to block the progression and symptoms of human immunodeficiency virus infection. Although it decreases morbidity and mortality, clinical use of HAART has also been linked to various adverse effects such as severe cardiomyopathy resulting from compromised mitochondrial functioning. However, the mechanistic basis for these effects remains unclear. Here, we demonstrate that a key component of HAART, 3ꞌ-azido-3ꞌ-deoxythymidine (AZT, particularly, its active metabolite AZT-triphosphate (AZT-TP, caused mitochondrial dysfunction, leading to induction of cell death in H9c2 cells derived from rat embryonic myoblasts, which serve as a model for cardiomyopathy. Specifically, treatment with 100 µM AZT for 48 h disrupted the mitochondrial tubular network via accumulation of AZT-TP. The mRNA expression of dynamin-related protein (Drp1 and the Drp1 receptor mitochondrial fission factor (Mff was upregulated whereas that of optic atrophy 1 (Opa1 was downregulated following AZT treatment. Increased mitochondrial translocation of Drp1, Mff upregulation, and decreased functional Opa1 expression induced by AZT impaired the balance of mitochondrial fission vs. fusion. These data demonstrate that AZT-TP causes cell death by altering mitochondrial dynamics.

  15. A novel role for the RNA-binding protein FXR1P in myoblasts cell-cycle progression by modulating p21/Cdkn1a/Cip1/Waf1 mRNA stability.

    Directory of Open Access Journals (Sweden)

    Laetitia Davidovic

    2013-03-01

    Full Text Available The Fragile X-Related 1 gene (FXR1 is a paralog of the Fragile X Mental Retardation 1 gene (FMR1, whose absence causes the Fragile X syndrome, the most common form of inherited intellectual disability. FXR1P plays an important role in normal muscle development, and its absence causes muscular abnormalities in mice, frog, and zebrafish. Seven alternatively spliced FXR1 transcripts have been identified and two of them are skeletal muscle-specific. A reduction of these isoforms is found in myoblasts from Facio-Scapulo Humeral Dystrophy (FSHD patients. FXR1P is an RNA-binding protein involved in translational control; however, so far, no mRNA target of FXR1P has been linked to the drastic muscular phenotypes caused by its absence. In this study, gene expression profiling of C2C12 myoblasts reveals that transcripts involved in cell cycle and muscular development pathways are modulated by Fxr1-depletion. We observed an increase of p21--a regulator of cell-cycle progression--in Fxr1-knocked-down mouse C2C12 and FSHD human myoblasts. Rescue of this molecular phenotype is possible by re-expressing human FXR1P in Fxr1-depleted C2C12 cells. FXR1P muscle-specific isoforms bind p21 mRNA via direct interaction with a conserved G-quadruplex located in its 3' untranslated region. The FXR1P/G-quadruplex complex reduces the half-life of p21 mRNA. In the absence of FXR1P, the upregulation of p21 mRNA determines the elevated level of its protein product that affects cell-cycle progression inducing a premature cell-cycle exit and generating a pool of cells blocked at G0. Our study describes a novel role of FXR1P that has crucial implications for the understanding of its role during myogenesis and muscle development, since we show here that in its absence a reduced number of myoblasts will be available for muscle formation/regeneration, shedding new light into the pathophysiology of FSHD.

  16. Simultaneous Transplantation of Fetal Ventral Mesencephalic Tissue and Encapsulated Genetically Modified Cells Releasing GDNF in a Hemi-Parkinsonian Rat Model of Parkinson's Disease.

    Science.gov (United States)

    Perez-Bouza, Alberto; Di Santo, Stefano; Seiler, Stefanie; Meyer, Morten; Andereggen, Lukas; Huber, Alexander; Guzman, Raphael; Widmer, Hans R

    2017-09-01

    Transplantation of fetal ventral mesencephalic (VM) neurons for Parkinson's disease (PD) is limited by poor survival and suboptimal integration of grafted tissue into the host brain. In a 6-hydroxydopamine rat model of PD, we investigated the feasibility of simultaneous transplantation of rat fetal VM tissue and polymer-encapsulated C2C12 myoblasts genetically modified to produce glial cell line-derived neurotrophic factor (GDNF) or mock-transfected myoblasts on graft function. Amphetamine-induced rotations were assessed prior to transplantation and 2, 4, 6 and 9 wk posttransplantation. We found that rats grafted with VM transplants and GDNF capsules showed a significant functional recovery 4 wk after implantation. In contrast, rats from the VM transplant and mock-capsule group did not improve at any time point analyzed. Moreover, we detected a significantly higher number of tyrosine hydroxylase immunoreactive (TH-ir) cells per graft (2-fold), a tendency for a larger graft volume and an overall higher TH-ir fiber outgrowth into the host brain (1.7-fold) in the group with VM transplants and GDNF capsules as compared to the VM transplant and mock-capsule group. Most prominent was the TH-ir fiber outgrowth toward the capsule (9-fold). Grafting of GDNF-pretreated VM transplants in combination with the implantation of GDNF capsules resulted in a tendency for a higher TH-ir fiber outgrowth into the host brain (1.7-fold) as compared to the group transplanted with untreated VM transplants and GDNF capsules. No differences between groups were observed for the number of surviving TH-ir neurons or graft volume. In conclusion, our findings demonstrate that simultaneous transplantation of fetal VM tissue and encapsulated GDNF-releasing cells is feasible and support the graft survival and function. Pretreatment of donor tissue with GDNF may offer a way to further improve cell transplantation approaches for PD.

  17. Novel and potent anti-tumor and anti-metastatic di-2-pyridylketone thiosemicarbazones demonstrate marked differences in pharmacology between the first and second generation lead agents.

    Science.gov (United States)

    Sestak, Vit; Stariat, Jan; Cermanova, Jolana; Potuckova, Eliska; Chladek, Jaroslav; Roh, Jaroslav; Bures, Jan; Jansova, Hana; Prusa, Petr; Sterba, Martin; Micuda, Stanislav; Simunek, Tomas; Kalinowski, Danuta S; Richardson, Des R; Kovarikova, Petra

    2015-12-15

    Di(2-pyridyl)ketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di(2-pyridyl)ketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) are novel, highly potent and selective anti-tumor and anti-metastatic drugs. Despite their structural similarity, these agents differ in their efficacy and toxicity in-vivo. Considering this, a comparison of their pharmacokinetic and pharmaco/toxico-dynamic properties was conducted to reveal if these factors are involved in their differential activity. Both compounds were administered to Wistar rats intravenously (2 mg/kg) and their metabolism and disposition were studied using UHPLC-MS/MS. The cytotoxicity of both thiosemicarbazones and their metabolites was also examined using MCF-7, HL-60 and HCT116 tumor cells and 3T3 fibroblasts and H9c2 cardiac myoblasts. Their intracellular iron-binding ability was characterized by the Calcein-AM assay and their iron mobilization efficacy was evaluated. In contrast to DpC, Dp44mT undergoes rapid demethylation in-vivo, which may be related to its markedly faster elimination (T1/2 = 1.7 h for Dp44mT vs. 10.7 h for DpC) and lower exposure. Incubation of these compounds with cancer cells or cardiac myoblasts did not result in any significant metabolism in-vitro. The metabolism of Dp44mT in-vivo resulted in decreased anti-cancer activity and toxicity. In conclusion, marked differences in the pharmacology of Dp44mT and DpC were observed and highlight the favorable pharmacokinetics of DpC for cancer treatment.

  18. Cytotoxicity and hemolytic activity of jellyfish Nemopilema nomurai (Scyphozoa: Rhizostomeae) venom.

    Science.gov (United States)

    Kang, Changkeun; Munawir, Al; Cha, Mijin; Sohn, Eun-Tae; Lee, Hyunkyoung; Kim, Jong-Shu; Yoon, Won Duk; Lim, Donghyun; Kim, Euikyung

    2009-07-01

    The recent bloom of a giant jellyfish Nemopilema nomurai has caused a danger to sea bathers and fishery damages in the waters of China, Korea, and Japan. The present study investigated the cytotoxic and hemolytic activities of crude venom extract of N. nomurai using a number of in vitro assays. The jellyfish venom showed a much higher cytotoxic activity in H9C2 heart myoblast than in C2C12 skeletal myoblast (LC(50)=2 microg/mL vs. 12 microg/mL, respectively), suggesting its possible in vivo selective toxicity on cardiac tissue. This result is consistent with our previous finding that cardiovascular function is a target of the venom. In order to determine the stability of N. nomurai venom, its cytotoxicity was examined under the various temperature and pH conditions. The activity was relatively well retained at low environmental temperature (or=60 degrees C). In pH stability test, the venom has abruptly lost its activity at low pH environment (pHrat. Venom concentration-dependent hemolysis could be observed from 10 microg/mL of protein equivalents or higher with variable potencies in different species, among which dog erythrocyte was the most susceptible to the venom (EC(50)=151 microg/mL). SDS-PAGE analysis of N. nomurai venom showed the molecules of 20-40 kDa and 10-15 kDa appeared to be the major protein components of the venom.

  19. ANKRD1 modulates inflammatory responses in C2C12 myoblasts through feedback inhibition of NF-κB signaling activity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin-Hua [National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States); Bauman, William A. [National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States); Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States); Cardozo, Christopher, E-mail: chris.cardozo@va.gov [National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peter VA Medical Center, Bronx, NY 10468 (United States); Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States); Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States); Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY 10029 (United States)

    2015-08-14

    Transcription factors of the nuclear factor-kappa B (NF-κB) family play a pivotal role in inflammation, immunity and cell survival responses. Recent studies revealed that NF-κB also regulates the processes of muscle atrophy. NF-κB activity is regulated by various factors, including ankyrin repeat domain 2 (AnkrD2), which belongs to the muscle ankyrin repeat protein family. Another member of this family, AnkrD1 is also a transcriptional effector. The expression levels of AnkrD1 are highly upregulated in denervated skeletal muscle, suggesting an involvement of AnkrD1 in NF-κB mediated cellular responses to paralysis. However, the molecular mechanism underlying the interactive role of AnkrD1 in NF-κB mediated cellular responses is not well understood. In the current study, we examined the effect of AnkrD1 on NF-κB activity and determined the interactions between AnkrD1 expression and NF-κB signaling induced by TNFα in differentiating C2C12 myoblasts. TNFα upregulated AnkrD1 mRNA and protein levels. AnkrD1-siRNA significantly increased TNFα-induced transcriptional activation of NF-κB, whereas overexpression of AnkrD1 inhibited TNFα-induced NF-κB activity. Co-immunoprecipitation studies demonstrated that AnkrD1 was able to bind p50 subunit of NF-κB and vice versa. Finally, CHIP assays revealed that AnkrD1 bound chromatin at a NF-κB binding site in the AnrkD2 promoter and required NF-κB to do so. These results provide evidence of signaling integration between AnkrD1 and NF-κB pathways, and suggest a novel anti-inflammatory role of AnkrD1 through feedback inhibition of NF-κB transcriptional activity by which AnkrD1 modulates the balance between physiological and pathological inflammatory responses in skeletal muscle. - Highlights: • AnkrD1 is upregulated by TNFα and represses NF-κB-induced transcriptional activity. • AnkrD1 binds to p50 subunit of NF-κB and is recruited to NF-κB bound to chromatin. • AnkrD1 mediates a feed-back inhibitory loop

  20. Methanolic extract of onion (Allium cepa) attenuates ischemia/hypoxia-induced apoptosis in cardiomyocytes via antioxidant effect.

    Science.gov (United States)

    Park, Sok; Kim, Mi-Young; Lee, Dong Ha; Lee, Soo Hwan; Baik, Eun Joo; Moon, Chang-Hyun; Park, Se Won; Ko, Eun Young; Oh, Sei-Ryang; Jung, Yi-Sook

    2009-06-01

    Although there is growing awareness of the beneficial potential of onion intake to lower the risk of cardiovascular disease, there is little information about the effect of onion on ischemic heart injury, one of the most common cardiovascular diseases. This study investigates the effect of the methanol-soluble extract of onion on ischemic injury in heart-derived H9c2 cells in vitro and in rat hearts in vivo. The underlying mechanism is also investigated. To evaluate the effect of onion on ischemia-induced cell death, LDH release and TUNEL-positivity were assessed in H9c2 cells, and the infarct size was measured in a myocardial infarct model. To investigate the mechanism of the cardioprotection by onion, the reactive oxygen species (ROS) level and the mitochondrial membrane potential (DeltaPsi(m)) were measured using an imaging technique; the caspase-3 activity was assayed, and Western blotting was performed to examine cytochrome c release in H9c2 cells. The methanolic extract of onion had a preventive effect on ischemia/hypoxia-induced apoptotic death in H9c2 cells in vitro and in rat heart in vivo. The onion extract (0.05 g/ml) inhibited the elevation of the ROS, mitochondrial membrane depolarization, cytochrome c release and caspase-3 activation during hypoxia in H9c2 cells. In the in vivo rat myocardial infarction model, onion extract (10 g/kg) significantly reduced the infarct size, the apoptotic cell death of the heart and the plasma MDA level. In conclusion, the results of this study suggest that the methanolic extract of onion attenuates ischemia/hypoxia-induced apoptosis in heart-derived H9c2 cells in vitro and in rat hearts in vivo, through, at least in part, an antioxidant effect.

  1. Testosterone enables growth and hypertrophy in fusion impaired myoblasts that display myotube atrophy: deciphering the role of androgen and IGF-I receptors.

    Science.gov (United States)

    Hughes, David C; Stewart, Claire E; Sculthorpe, Nicholas; Dugdale, Hannah F; Yousefian, Farzad; Lewis, Mark P; Sharples, Adam P

    2016-06-01

    We have previously highlighted the ability of testosterone (T) to improve differentiation and myotube hypertrophy in fusion impaired myoblasts that display reduced myotube hypertrophy via multiple population doublings (PD) versus their parental controls (CON); an observation which is abrogated via PI3K/Akt inhibition (Deane et al. 2013). However, whether the most predominant molecular mechanism responsible for T induced hypertrophy occurs directly via androgen receptor or indirectly via IGF-IR/PI3K/Akt pathway is currently debated. PD and CON C2C12 muscle cells were exposed to low serum conditions in the presence or absence of T (100 nM) ± inhibitors of AR (flutamide/F, 40 μm) and IGF-IR (picropodophyllin/PPP, 150 nM) for 72 h and 7 days (early/late muscle differentiation respectively). T increased AR and Akt abundance, myogenin gene expression, and myotube hypertrophy, but not ERK1/2 activity in both CON and PD cell types. Akt activity was not increased significantly in either cell type with T. Testosterone was also unable to promote early differentiation in the presence of IGF-IR inhibitor (PPP) yet still able to promote appropriate later increases in myotube hypertrophy and AR abundance despite IGF-IR inhibition. The addition of the AR inhibitor powerfully attenuated all T induced increases in differentiation and myotube hypertrophy with corresponding reductions in AR abundance, phosphorylated Akt, ERK1/2 and gene expression of IGF-IR, myoD and myogenin with increases in myostatin mRNA in both cell types. Interestingly, despite basally reduced differentiation and myotube hypertrophy, PD cells showed larger T induced increases in AR abundance vs. CON cells, a response abrogated in the presence of AR but not IGF-IR inhibitors. Furthermore, T induced increases in Akt abundance were sustained despite the presence of IGF-IR inhibition in PD cells only. Importantly, flutamide alone reduced IGF-IR mRNA in both cell types across time points, with an observed

  2. Bone morphogenetic protein-2 functions as a negative regulator in the differentiation of myoblasts, but not as an inducer for the formations of cartilage and bone in mouse embryonic tongue

    Directory of Open Access Journals (Sweden)

    Suzuki Erika

    2011-07-01

    Full Text Available Abstract Background In vitro studies using the myogenic cell line C2C12 demonstrate that bone morphogenetic protein-2 (BMP-2 converts the developmental pathway of C2C12 from a myogenic cell lineage to an osteoblastic cell lineage. Further, in vivo studies using null mutation mice demonstrate that BMPs inhibit the specification of the developmental fate of myogenic progenitor cells. However, the roles of BMPs in the phases of differentiation and maturation in skeletal muscles have yet to be determined. The present study attempts to define the function of BMP-2 in the final stage of differentiation of mouse tongue myoblast. Results Recombinant BMP-2 inhibited the expressions of markers for the differentiation of skeletal muscle cells, such as myogenin, muscle creatine kinase (MCK, and fast myosin heavy chain (fMyHC, whereas BMP-2 siRNA stimulated such markers. Neither the recombinant BMP-2 nor BMP-2 siRNA altered the expressions of markers for the formation of cartilage and bone, such as osteocalcin, alkaline phosphatase (ALP, collagen II, and collagen X. Further, no formation of cartilage and bone was observed in the recombinant BMP-2-treated tongues based on Alizarin red and Alcian blue stainings. Neither recombinant BMP-2 nor BMP-2 siRNA affected the expression of inhibitor of DNA binding/differentiation 1 (Id1. The ratios of chondrogenic and osteogenic markers relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH, a house keeping gene were approximately 1000-fold lower than those of myogenic markers in the cultured tongue. Conclusions BMP-2 functions as a negative regulator for the final differentiation of tongue myoblasts, but not as an inducer for the formation of cartilage and bone in cultured tongue, probably because the genes related to myogenesis are in an activation mode, while the genes related to chondrogenesis and osteogenesis are in a silencing mode.

  3. The inhibition of cultured myoblast differentiation by the simian virus 40 large T antigen occurs after myogenin expression and Rb up-regulation and is not exerted by transformation-competent cytoplasmic mutants.

    Science.gov (United States)

    Tedesco, D; Caruso, M; Fischer-Fantuzzi, L; Vesco, C

    1995-11-01

    We have investigated the mechanism by which the simian virus 40 large T antigen (SVLT) interferes with the differentiation of C2 myoblasts. SVLT mutants, defective either in the Rb binding site, near the N-terminal end, in a region that affects binding to p53, or in the nuclear transport signal, were also employed to determine whether the interference was especially dependent on these functional domains. It was found that wild-type (wt) SVLT strongly inhibited the terminal differentiation of mouse C2 myoblasts, but this arrest occurred only after the synthesis of myogenin, an initial step in biochemical differentiation. Neither the synthesis nor some basic activities of MyoD appeared to be affected by wt SVLT. In these transformants, mitogen depletion elicited an increase in the Rb level comparable to that in normal C2 cells; wt SVLT, however, promoted the phosphorylation of a large part of the induced Rb. Mutations affecting nuclear transport were far more critical for the ability to interfere with myogenic differentiation than were those affecting the transforming potential; cytoplasmic SVLT expression was fully compatible with the terminal differentiation of C2 cells, despite enabling them to grow in semisolid medium, thus showing that the myogenesis-inhibiting property can be dissociated from transforming competence. The remaining SVLT mutants presented different degrees of ability to inhibit differentiation (as shown by the expression of tissue-specific markers in transformants). The inhibiting mutants, including the Rb binding site mutant, were able to promote a higher state of Rb phosphorylation than that observed in either normal cells or cytoplasmic-SVLT transformants.

  4. Isolation and characterization of a novel gene sfig in rat skeletal muscle up-regulated by spaceflight (STS-90)

    Science.gov (United States)

    Kano, Mihoko; Kitano, Takako; Ikemoto, Madoka; Hirasaka, Katsuya; Asanoma, Yuki; Ogawa, Takayuki; Takeda, Shinichi; Nonaka, Ikuya; Adams, Gregory R.; Baldwin, Kenneth M.; hide

    2003-01-01

    We obtained the skeletal muscle of rats exposed to weightless conditions during a 16-day-spaceflight (STS-90). By using a differential display technique, we identified 6 up-regulated and 3 down-regulated genes in the gastrocnemius muscle of the spaceflight rats, as compared to the ground control. The up-regulated genes included those coding Casitas B-lineage lymphoma-b, insulin growth factor binding protein-1, titin and mitochondrial gene 16 S rRNA and two novel genes (function unknown). The down-regulated genes included those encoding RNA polymerase II elongation factor-like protein, NADH dehydrogenase and one novel gene (function unknown). In the present study, we isolated and characterized one of two novel muscle genes that were remarkably up-regulated by spaceflight. The deduced amino acid sequence of the spaceflight-induced gene (sfig) comprises 86 amino acid residues and is well conserved from Drosophila to Homo sapiens. A putative leucine-zipper structure located at the N-terminal region of sfig suggests that this gene may encode a transcription factor. The up-regulated expression of this gene, confirmed by Northern blot analysis, was observed not only in the muscles of spaceflight rats but also in the muscles of tail-suspended rats, especially in the early stage of tail-suspension when gastrocnemius muscle atrophy initiated. The gene was predominantly expressed in the kidney, liver, small intestine and heart. When rat myoblastic L6 cells were grown to 100% confluence in the cell culture system, the expression of sfig was detected regardless of the cell differentiation state. These results suggest that spaceflight has many genetic effects on rat skeletal muscle.

  5. Clonal derivation of a rat muscle cell strain that forms contraction-competent myotubes.

    Science.gov (United States)

    Merrill, G F

    1989-05-01

    A muscle cell strain capable of forming contracting myotubes was isolated from an established rat embryo cell line. The myogenic cells, termed rat myoblast omega or RMo cells, have a diploid complement of chromosomes (n = 42). In the presence of mitogen-containing growth medium, RMo cells proliferated with a cell generation time of about 12 hours. In mitogen-depleted medium, RMo cells withdrew from the cell cycle and formed myotubes that spontaneously contracted. Differentiated RMo cells produced creatine kinase isozymes in a ratio characteristic of skeletal muscle cells. RMo cells were easy to cultivate. Cells proliferated and differentiated equally well on gelatin-coated or noncoated culture dishes, at clonal or mass culture densities, and in all basal media tested. In most experiments, growth medium consisted of horse serum-containing medium supplemented with either chicken embryo extract or FGF activity; cells proliferated equally well in medium containing unsupplemented calf serum. RMo cells differentiated if growth medium was not replenished regularly. Alternatively, differentiation was induceable by incubation in mitogen-depleted medium consisting of basal medium supplemented either with 10(-6) M insulin, 0.5% serum, or 50% conditioned growth medium. RMo cells were competently transformed with cloned exogenous genes. Because it forms functional myofibrils, the RMo cell line constitutes a useful model system for studying the cell biology and biochemistry of proteins involved in contractile apparatus assembly and muscle disease.

  6. Small activating RNA induces myogenic differentiation of rat adipose-derived stem cells by upregulating MyoD

    Directory of Open Access Journals (Sweden)

    Chenghe Wang

    2015-08-01

    Full Text Available ABSTRACTPurpose:RNA activation (RNAa is a mechanism of gene activation triggered by promoter-targeted small double stranded RNAs (dsRNAs, also known as small activating RNAs (saRNAs. Myogenic regulatory factor MyoD is regarded as the master activator of myogenic differentiation cascade by binding to enhancer of muscle specific genes. Stress urinary incontinence (SUI is a condition primarily resulted from urethral sphincter deficiency. It is thus expected that by promoting differentiation of adipose-derived stem cells (ADSCs into myoblasts by activating MyoD gene through RNAa may offer benefits to SUI.Materials and Methods:Rats ADSCs were isolated, proliferated in vitro, and identified by flow cytometry. Purified ADSCs were then transfected with a MyoD saRNA or control transfected. Real-time polymerase chain reaction (RT-PCR and western blotting were used to detect MyoD mRNA and protein expression, respectively. Immunocytochemical staining was applied to determine the expression of desmin protein in transfected cells. Cell viability was measured by using CellTiter 96® AQueous One Solution Cell Proliferation Assay kit.Results:Transfection of a MyoD saRNA (dsMyoD into ADSCs significantly induced the expression of MyoD at both the mRNA and protein levels, and inhibited cell proliferation. Desmin protein expression was detected in dsMyoD treated ADSCs 2 weeks later.Conclusion:Our findings show that RNAa mediated overexpression of MyoD can promote transdifferentiation of ADSCs into myoblasts and may help treat stress urinary incontinence (SUI–a condition primarily resulted from urethral sphincter deficiency.

  7. Reducible poly(amido ethylenediamine) for hypoxia-inducible VEGF delivery

    NARCIS (Netherlands)

    Christensen, Lane V.; Christensen, L.; Chang, Chien-Wen; Yockman, James W.; Conners, Rafe; Jackson, Heidi; Zhong, Zhiyuan; Feijen, Jan; Bull, David A.; Kim, Sung Wan

    2007-01-01

    Delivery of the hypoxia-inducible vascular endothelial growth factor (RTP-VEGF) plasmid using a novel reducible disulfide poly(amido ethylenediamine) (SS-PAED) polymer carrier was studied in vitro and in vivo. In vitro transfection of primary rat cardiomyoblasts (H9C2) showed SS-PAED at a weighted

  8. Application of direct HPTLC-MALDI for the qualitative and quantitative profiling of neutral and acidic glycosphingolipids: the case of NEU3 overexpressing C2C12 murine myoblasts.

    Science.gov (United States)

    Torretta, Enrica; Vasso, Michele; Fania, Chiara; Capitanio, Daniele; Bergante, Sonia; Piccoli, Marco; Tettamanti, Guido; Anastasia, Luigi; Gelfi, Cecilia

    2014-05-01

    Glycosphingolipids (GSLs) are a class of ubiquitous lipids characterized by a wide structural repertoire and a variety of functional implications. Importantly, altered levels have been correlated with different diseases, suggesting their crucial role in health. Conventional methods for the characterization and quantification are based on high-performance TLC (HPTLC) separation and comparison with the migration distance of standard samples or on MS. We set up and herein report the application of an ImagePrep method for glycosphingolipids qualitative and quantitative profiling through direct HPTLC-MALDI with particular application to wild-type and NEU3 sialidase-overexpressing C2C12 myoblasts. Lipids were analyzed by HPTLC, coupled with MALDI-TOF, and the resulting GSLs profiles were compared to the [³H]sphingolipids HPTLC patterns obtained after metabolic radiolabeling. GSLs detection by HPTLC-MALDI was optimized by testing different methods for matrix delivery and by performing quantitative analyses using serial dilutions of GSLs standards. Through this approach an accurate analysis of each variant of neutral and acidic GSLs, including the detection of different fatty-acid chain variants for each GSL, was provided and these results demonstrated that HPTLC-MALDI is an easy and high-throughput analytical method for GSLs profiling, suggesting its use for an early detection of markers in different diseases, including cancer and heart ischemia. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Rat-bite fever

    Science.gov (United States)

    ... dwellings may help prevent rat-bite fever. Taking antibiotics by mouth after a rat bite may also help prevent this illness. Alternative Names Streptobacillary fever; Streptobacillosis; Haverhill fever; Epidemic arthritic ...

  10. Rat Genome Database (RGD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Rat Genome Database (RGD) is a collaborative effort between leading research institutions involved in rat genetic and genomic research to collect, consolidate,...

  11. A novel fission-independent role of dynamin-related protein 1 in cardiac mitochondrial respiration.

    Science.gov (United States)

    Zhang, Huiliang; Wang, Pei; Bisetto, Sara; Yoon, Yisang; Chen, Quan; Sheu, Shey-Shing; Wang, Wang

    2017-02-01

    Mitochondria in adult cardiomyocytes exhibit static morphology and infrequent dynamic changes, despite the high abundance of fission and fusion regulatory proteins in the heart. Previous reports have indicated that fusion proteins may bear functions beyond morphology regulation. Here, we investigated the role of fission protein, dynamin-related protein 1 (DRP1), on mitochondrial respiration regulation in adult cardiomyocytes. By using genetic or pharmacological approaches, we manipulated the activity or protein level of fission and fusion proteins and found they mildly influenced mitochondrial morphology in adult rodent cardiomyocytes, which is in contrast to their significant effect in H9C2 cardiac myoblasts. Intriguingly, inhibiting endogenous DRP1 by dominant-negative DRP1 mutation (K38A), shRNA, or Mdivi-1 suppressed maximal respiration and respiratory control ratio in isolated mitochondria from adult mouse heart or in adult cardiomyocytes from rat. Meanwhile, basal respiration was increased due to increased proton leak. Facilitating mitofusin-mediated fusion by S3 compound, however, failed to inhibit mitochondrial respiration in adult cardiomyocytes. Mechanistically, DRP1 inhibition did not affect the maximal activity of individual respiratory chain complexes or the assembly of supercomplexes. Knocking out cyclophilin D, a regulator of mitochondrial permeability transition pore (mPTP), abolished the effect of DRP1 inhibition on respiration. Finally, DRP1 inhibition decreased transient mPTP-mediated mitochondrial flashes, delayed laser-induced mPTP opening and suppressed mitochondrial reactive oxygen species (ROS). These results uncover a novel non-canonical function of the fission protein, DRP1 in maintaining or positively stimulating mitochondrial respiration, bioenergetics and ROS signalling in adult cardiomyocyte, which is likely independent of morphological changes. Published on behalf of the European Society of Cardiology. All rights reserved. © The

  12. Impaired ergosterol biosynthesis mediated fungicidal activity of Co(II) complex with ligand derived from cinnamaldehyde.

    Science.gov (United States)

    Shreaz, Sheikh; Shiekh, Rayees A; Raja, Vaseem; Wani, Waseem A; Behbehani, Jawad M

    2016-03-05

    In this study, we have used aldehyde function of cinnamaldehyde to synthesize N, N'-Bis (cinnamaldehyde) ethylenediimine [C20H20N2] and Co(II) complex of the type [Co(C40H40N4)Cl2]. The structures of the synthesized compounds were determined on the basis of physiochemical analysis and spectroscopic data ((1)H NMR, FTIR, UV-visible and mass spectra) along with molar conductivity measurements. Anticandidal activity of cinnamaldehyde its ligand [L] and Co(II) complex was investigated by determining MIC80, time-kill kinetics, disc diffusion assay and ergosterol extraction and estimation assay. Ligand [L] and Co(II) complex are found to be 4.55 and 21.0 folds more efficient than cinnamaldehyde in a liquid medium. MIC80 of Co(II) complex correlated well with ergosterol inhibition suggesting ergosterol biosynthesis to be the primary site of action. In comparison to fluconazole, the test compounds showed limited toxicity against H9c2 rat cardiac myoblasts. In confocal microscopy propidium iodide (PI) penetrates the yeast cells when treated with MIC of metal complex, indicating a disruption of cell membrane that results in imbibition of dye. TEM analysis of metal complex treated cells exhibited notable alterations or damage to the cell membrane and the cell wall. The structural disorganization within the cell cytoplasm was noted. It was concluded that fungicidal activity of Co(II) complex originated from loss of membrane integrity and a decrease in ergosterol content is only one consequence of this. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Rat Bite Fever

    Science.gov (United States)

    ... Issues Listen Español Text Size Email Print Share Rat Bite Fever Page Content Article Body Rat-bite fever is a disease that occurs in humans who have been bitten by an infected rat or, in some cases, squirrels, mice, cats, and ...

  14. Effects of Chitosan Coatings on Polypropylene Mesh for Implantation in a Rat Abdominal Wall Model

    Science.gov (United States)

    Udpa, Natasha; Iyer, Shama R.; Rajoria, Rohit; Breyer, Kate E.; Valentine, Helen; Singh, Bhupinder; McDonough, Sean P.; Brown, Bryan N.; Bonassar, Lawrence J.

    2013-01-01

    Hernia repair and pelvic floor reconstruction are usually accompanied with the implantation of a surgical mesh, which frequently results in a foreign body response with associated complications. An ideal surgical mesh that allows force generation of muscle tissues without significant granulation tissue and/or fibrosis is of significant clinical interest. The objective of the present study was to evaluate the in vitro and in vivo responses of a chitosan coating on polypropylene mesh (Ch-PPM) in comparison with commercially available meshes. We found that application of a 0.5% (w/v) Ch-PPM elicited preferential attachment of myoblasts over fibroblast attachment in vitro. Therefore, we test the hypothesis that 0.5% Ch-PPM will encourage skeletal muscle tissue ingrowth and decrease fibrosis formation in vivo. We implanted 0.5% Ch-PPM, collagen-coated polypropylene mesh (Pelvitex™; C.R. Bard), and polypropylene (Avaulta Solo®; C.R. Bard) alone using a rat abdominal defect model. Force generation capacity and inflammatory response of each mesh were evaluated 2, 4, and 12 weeks postimplantation. We found that chitosan coating is associated with the restoration of functional skeletal muscle with histomorphologic characteristics that resemble native muscle and an early macrophage phenotypic response that has previously been shown to lead to more functional outcomes. PMID:23859182

  15. Induction of cyclins E and A in response to mitogen removal: a basic alteration associated with the arrest of differentiation of C2 myoblasts transformed by simian virus 40 large T antigen.

    Science.gov (United States)

    Tedesco, D; Baron, L; Fischer-Fantuzzi, L; Vesco, C

    1997-03-01

    We previously showed that C2 myoblasts transformed by simian virus 40 large T antigen (SVLT) stop the myogenic process after the induction of myogenin and of high Rb levels; the induced Rb, however, becomes notably phosphorylated. We have analyzed the protein levels and activities of cyclin-dependent kinases (cdks) in untransformed C2 cells and in transformants of either SVLT or the cytoplasmic mutant NKT1 (which permits differentiation) upon a shift from growth medium (GM) to mitogen-poor differentiation medium (DM). After the shift, cdk4 levels remained constant and cdk6 levels decreased in all cell types; cdk2 minimally increased only in SVLT cells. Cyclin D1 was downregulated in DM in all cell types, and cyclin D3 was upregulated (albeit less strongly in SVLT cells than in the others). In contrast, a dramatic difference between SVLT cells and the other cells was observed for cyclins E and A, which essentially disappeared (as protein and RNA) in normal C2 and NKT1 cells upon the shift from GM to DM, whereas they increased in SVLT cells. Concurrently, cdk2 activity ceased in C2 and NKT1 cells in DM, whereas it persisted at 20% of the GM level in SVLT cells. cdk4 activity was detectable in all cells only in GM. Cyclin E and A induction thus appeared to sustain enough Rb phosphorylation to interfere with tissue-specific expression, with cdk activity not high enough to activate cyclin self-regulation. In DM, cdk2 complexed to D3 was underphosphorylated in all cells, and SVLT allowed strong inductions of p21 and p27 without affecting their complexes with cdks.

  16. Histological analysis of heart after domoic acid administration in rats

    Directory of Open Access Journals (Sweden)

    Andrés Crespo Vieira

    2014-06-01

    All data were analysed with GraphPad Prism 5.0 by a one-way analysis of variance (ANOVA. Dunnett’s Multiple Comparison test was used for post hoc comparisons between control and treatment groups. Results were expressed as means ± SEM, with a P value of Zalophus californianus (Gulland et al. 2002; Zabka et al. 2009, although these effects were no studied under experimental conditions due to that they were natural intoxications. In vitro studies showed that DOM produced alterations in the metabolism of rat cardiac myoblasts (Nijjar et al. 1999; Vranyac-Tramoundanas et al. 2008, but few in vivo observations are reduced to a previous report by Vranyac-Tramoundanas (Vranyac-Tramoundanas et al. 2011, where heart lesions were seen 3 days i.p. administration. The early onset of the heart lesions, characteristic of acute damage, led us to realize the present assay, where we expected to observe some kind of heart damage or collagen alterations. The possible observed damage would be correlated with the presence of DOM by IHQ assays. The experimental dose (2.5 mg/kg and the antibody concentration (1:5000 were determined by previous experiments (Vieira et al., in press. Our previous observations showed an important presence of DOM only in hippocampus 6h and 10h after toxin i.p. administration (Vieira et al., in press. Neuropathological studies in rodents concluded that hippocampus constitutes the principal target of DOM, due to the high concentration of KA receptors in this area (Wisden 1993. In spite of the presence of GluRs in rat heart (Gill et al. 1998, the DOM affinity for these GluRs or the concentration of GluRs might not be high enough to detect DOM presence 6h, 10h or 24h after i.p. administration. The mild collagen alterations and the lack of observable damage in the first 24 h after toxin administration concluded that DOM seems to need several days in order to produce observable damage. Further experiments with long-time expositions to DOM will be done.

  17. MiR-21 Protected Cardiomyocytes against Doxorubicin-Induced Apoptosis by Targeting BTG2

    Directory of Open Access Journals (Sweden)

    Zhongyi Tong

    2015-06-01

    Full Text Available Doxorubicin (DOX is an anthracycline drug with a wide spectrum of antineoplastic activities. However, it causes cardiac cytotoxicity, and this limits its clinical applications. MicroRNA-21 (miR-21 plays a vital role in regulating cell proliferation and apoptosis. While miR-21 is preferentially expressed in adult cardiomyocytes and involved in cardiac development and heart disease, little is known regarding its biological functions in responding to DOX-induced cardiac cytotoxicity. In this study, the effects of DOX on mouse cardiac function and the expression of miR-21 were examined in both mouse heart tissues and rat H9C2 cardiomyocytes. The results showed that the cardiac functions were more aggravated in chronic DOX injury mice compared with acute DOX-injury mice; DOX treatment significantly increased miR-21 expression in both mouse heart tissue and H9C2 cells. Over-expression of miR-21 attenuated DOX-induced apoptosis in cardiamyocytes whereas knocking down its expression increased DOX-induced apoptosis. These gain- and loss- of function experiments showed that B cell translocation gene 2 (BTG2 was a target of miR-21. The expression of BTG2 was significantly decreased both in myocardium and H9C2 cells treated with DOX. The present study has revealed that miR-21 protects mouse myocardium and H9C2 cells against DOX-induced cardiotoxicity probably by targeting BTG2.

  18. Oleanolic acid: a novel cardioprotective agent that blunts hyperglycemia-induced contractile dysfunction.

    Directory of Open Access Journals (Sweden)

    Rudo F Mapanga

    Full Text Available Diabetes constitutes a major health challenge. Since cardiovascular complications are common in diabetic patients this will further increase the overall burden of disease. Furthermore, stress-induced hyperglycemia in non-diabetic patients with acute myocardial infarction is associated with higher in-hospital mortality. Previous studies implicate oxidative stress, excessive flux through the hexosamine biosynthetic pathway (HBP and a dysfunctional ubiquitin-proteasome system (UPS as potential mediators of this process. Since oleanolic acid (OA; a clove extract possesses antioxidant properties, we hypothesized that it attenuates acute and chronic hyperglycemia-mediated pathophysiologic molecular events (oxidative stress, apoptosis, HBP, UPS and thereby improves contractile function in response to ischemia-reperfusion. We employed several experimental systems: 1 H9c2 cardiac myoblasts were exposed to 33 mM glucose for 48 hr vs. controls (5 mM glucose; and subsequently treated with two OA doses (20 and 50 µM for 6 and 24 hr, respectively; 2 Isolated rat hearts were perfused ex vivo with Krebs-Henseleit buffer containing 33 mM glucose vs. controls (11 mM glucose for 60 min, followed by 20 min global ischemia and 60 min reperfusion ± OA treatment; 3 In vivo coronary ligations were performed on streptozotocin treated rats ± OA administration during reperfusion; and 4 Effects of long-term OA treatment (2 weeks on heart function was assessed in streptozotocin-treated rats. Our data demonstrate that OA treatment blunted high glucose-induced oxidative stress and apoptosis in heart cells. OA therapy also resulted in cardioprotection, i.e. for ex vivo and in vivo rat hearts exposed to ischemia-reperfusion under hyperglycemic conditions. In parallel, we found decreased oxidative stress, apoptosis, HBP flux and proteasomal activity following ischemia-reperfusion. Long-term OA treatment also improved heart function in streptozotocin-diabetic rats. These

  19. SWEEP Project RAT

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Madsen, Søren; Petersen, L. B.

    This report presents the results from the design analyses made for the clustered suction caisson used as foundation for a Riser Access Tower (RAT). The RAT is intended built next to the K15-FA-1 Platform in the Dutch Sector of the North Sea....

  20. [Comparative investigation of antigens associated with plasmatic membranes of rat hepatoma and myogenic cells using anti-kidney serum].

    Science.gov (United States)

    Teriukova, N P; Desheva, A S; Blinova, G I; Mirgorodskaia, O A; Ivanov, V A

    2007-01-01

    The investigation of antigenic diversion of tumor cells resulting from the expression of heteroorganic antigens has been continued. Tumor-associated heteroorganic antigens with mol. weight 200-210 kDa (identified before as laminin), 105-130, 75-80 and 43 kDa were detected by anti-kidney serum in fractions of plasmatic membranes of cells of rat ascitic Zajdela hepatoma and cultured HTC hepatoma; the antigen 43 kDa was isolated on immunosorbent and identified by mass spectrometry as beta-actin. Anti-kidney serum revealed laminin in fractions of plasmatic membranes of cultured L8 and L6J1 myoblasts, and L6J1 myotubes; apparently, synthesis of laminin by hepatoma and myogenic cells is not connected with their proliferative activity. Besides, anti-kidney serum detected components 38, 42, 44, 48, 62, 78 and 120 kDa, expression of which on myogenic cells surface might be consequence of active cell proliferation and (or) differentiation.

  1. No Evidence of Rat Hepatitis E Virus Excretion in Urine Samples of Rats.

    Science.gov (United States)

    Li, Tian-Cheng; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Johne, Reimar; Wakita, Takaji

    2017-05-24

    To investigate whether rat hepatitis E virus (rat HEV) is excreted in the urine of HEV-infected rats, we infected 3 Wistar and 6 nude rats with rat HEV and examined the rat-HEV RNA in serum, fecal, and urine samples. We detected rat-HEV RNA in the serum and fecal samples of all 9 rats but not in any of the urine samples. Our results suggest that in rats, rat HEV is not transmitted via urine.

  2. Longtransplantatie bij de rat

    NARCIS (Netherlands)

    Marck, Klaas Willem

    1983-01-01

    Op grond van de resultaten van het hierboven beschreven onderzoek en de eraan gewijde beschouwingen zijn de volgende conclasies getrokken: 1. Orthotope linkszijdige longtransplantatie bij de rat is operatietechnisch mogelijk. 2. Longpercusiescintigrafie met radioactief ,,gelabelde" microbolletjes is

  3. Shikonin increases glucose uptake in skeletal muscle cells and improves plasma glucose levels in diabetic Goto-Kakizaki rats.

    Directory of Open Access Journals (Sweden)

    Anette I Öberg

    Full Text Available BACKGROUND: There is considerable interest in identifying compounds that can improve glucose homeostasis. Skeletal muscle, due to its large mass, is the principal organ for glucose disposal in the body and we have investigated here if shikonin, a naphthoquinone derived from the Chinese plant Lithospermum erythrorhizon, increases glucose uptake in skeletal muscle cells. METHODOLOGY/PRINCIPAL FINDINGS: Shikonin increases glucose uptake in L6 skeletal muscle myotubes, but does not phosphorylate Akt, indicating that in skeletal muscle cells its effect is medaited via a pathway distinct from that used for insulin-stimulated uptake. Furthermore we find no evidence for the involvement of AMP-activated protein kinase in shikonin induced glucose uptake. Shikonin increases the intracellular levels of calcium in these cells and this increase is necessary for shikonin-mediated glucose uptake. Furthermore, we found that shikonin stimulated the translocation of GLUT4 from intracellular vesicles to the cell surface in L6 myoblasts. The beneficial effect of shikonin on glucose uptake was investigated in vivo by measuring plasma glucose levels and insulin sensitivity in spontaneously diabetic Goto-Kakizaki rats. Treatment with shikonin (10 mg/kg intraperitoneally once daily for 4 days significantly decreased plasma glucose levels. In an insulin sensitivity test (s.c. injection of 0.5 U/kg insulin, plasma glucose levels were significantly lower in the shikonin-treated rats. In conclusion, shikonin increases glucose uptake in muscle cells via an insulin-independent pathway dependent on calcium. CONCLUSIONS/SIGNIFICANCE: Shikonin increases glucose uptake in skeletal muscle cells via an insulin-independent pathway dependent on calcium. The beneficial effects of shikonin on glucose metabolism, both in vitro and in vivo, show that the compound possesses properties that make it of considerable interest for developing novel treatment of type 2 diabetes.

  4. Calpain 3 Expression Pattern during Gastrocnemius Muscle Atrophy and Regeneration Following Sciatic Nerve Injury in Rats

    Directory of Open Access Journals (Sweden)

    Ronghua Wu

    2015-11-01

    Full Text Available Calpain 3 (CAPN3, also known as p94, is a skeletal muscle-specific member of the calpain family that is involved in muscular dystrophy; however, the roles of CAPN3 in muscular atrophy and regeneration are yet to be understood. In the present study, we attempted to explain the effect of CAPN3 in muscle atrophy by evaluating CAPN3 expression in rat gastrocnemius muscle following reversible sciatic nerve injury. After nerve injury, the wet weight ratio and cross sectional area (CSA of gastrocnemius muscle were decreased gradually from 1–14 days and then recovery from 14–28 days. The active form of CAPN3 (~62 kDa protein decreased slightly on day 3 and then increased from day 7 to 14 before a decrease from day 14 to 28. The result of linear correlation analysis showed that expression of the active CAPN3 protein level was negatively correlated with muscle wet weight ratio. CAPN3 knockdown by short interfering RNA (siRNA injection improved muscle recovery on days 7 and 14 after injury as compared to that observed with control siRNA treatment. Depletion of CAPN3 gene expression could promote myoblast differentiation in L6 cells. Based on these findings, we conclude that the expression pattern of the active CAPN3 protein is linked to muscle atrophy and regeneration following denervation: its upregulation during early stages may promote satellite cell renewal by inhibiting differentiation, whereas in later stages, CAPN3 expression may be downregulated to stimulate myogenic differentiation and enhance recovery. These results provide a novel mechanistic insight into the role of CAPN3 protein in muscle regeneration after peripheral nerve injury.

  5. in albino rats

    African Journals Online (AJOL)

    hope&shola

    2010-09-23

    Sep 23, 2010 ... cell carcinoma, malignant fibrous histiocytoma, atrophy, fibro- sarcoma, chronic inflammation, squamous cell carcinoma in situ and osteoma at the end of the experiment. The lesions were then diagnosed according to the histopathological changes by using ether to anesthetize the rats. All the animals were ...

  6. CAMALDULENSIS IN RATS

    African Journals Online (AJOL)

    DR. AMIN

    ABSTRACT. Sub – acute toxicity study of the aqueous leaf extract of Eucalyptus camaldulensis was carried out on albino rats. Doses of 250mg, 500mg, 750mg and 1000mg per kilogram body weight of the extract were administered orally for 21 days. The activities of Alanine Aminotransferase (ALT),. Aspartate ...

  7. The academic rat race

    DEFF Research Database (Denmark)

    Landes, Xavier; Andersen, Martin Marchman; Nielsen, Morten Ebbe Juul

    2012-01-01

    : an increased pressure to produce articles (in peer-reviewed journals) has created an unbalanced emphasis on the research criterion at the expense of the latter two. More fatally, this pressure has turned academia into a rat race, leading to a deep change in the fundamental structure of academic behaviour...

  8. Running the rat race

    African Journals Online (AJOL)

    SASA Refresher Course Texts: Running the rat race. 74. 2014;20(1) ... and feelings of existential despair which characterise the human condition, to emerge as they are today: whole, satisfied, well .... Pure efficiency only exists on paper. In the ...

  9. Rat on Mars

    Science.gov (United States)

    2004-01-01

    This image taken on Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's rock abrasion tool, also known as 'rat' (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  10. Behavior modulation of rats to a robotic rat in multi-rat interaction.

    Science.gov (United States)

    Shi, Qing; Ishii, Hiroyuki; Tanaka, Katsuaki; Sugahara, Yusuke; Takanishi, Atsuo; Okabayashi, Satoshi; Huang, Qiang; Fukuda, Toshio

    2015-09-28

    In this paper, we study the behavioral response of rats to a robotic rat during multi-rat interaction. Experiments are conducted in an open-field where a robotic rat called WR-5 is put together with three laboratory rats. WR-5 is following one rat (target), while avoiding the other two rats (outside observers) during interaction. The behavioral characteristics of each target rat is evaluated by scoring its locomotor activity and frequencies of performing rearing, body grooming and mounting actions. Additionally, the frequency of being mounted by other rats is also measured. Experimental results show that the target becomes more active after interaction. The rat species, with more active behavioral characteristics, is more susceptible to being adjusted by the robot. The increased time spent by the outside observers in the vicinity of the robot indicates that a biomimetic robot has the promise for modulating rat behavior even without direct interaction. Thus, this study provide a novel approach to shaping the sociality of animals living in groups.

  11. Dexamethasone effects on creatine kinase activity and insulin-like growth factor receptors in cultured muscle cells

    Science.gov (United States)

    Whitson, Peggy A.; Stuart, Charles A.; Huls, M. H.; Sams, Clarence F.; Cintron, Nitza M.

    1989-01-01

    The effect of dexamethasone on the activity of creatine kinase (CK) and the insulin-like growth factor I (IGF-I) binding were investigated using skeletal- and cardiac-muscle-derived cultured cell lines (mouse, C2C12; rat, L6 and H9c2). It was found that, in skeletal muscle cells, dexamethasone treatment during differentiation of skeletal-muscle cells caused dose-dependent increases in CK activity and increases in the degree of myotube formation, whereas cardiac cells (H9c2) exhibited very low CK activity during culture or dexamethasone treatment. Results for IGF-I binding were similar in all three cell lines. The IGF-I binding to dexamethasone-treated cells (50 nM for 24 hr on the day prior to confluence) resulted in an increased number of available binding sites, with no effect on the binding affinities.

  12. MicroRNAs overexpressed in growth-restricted rat skeletal muscles regulate the glucose transport in cell culture targeting central TGF-β factor SMAD4.

    Science.gov (United States)

    Raychaudhuri, Santanu

    2012-01-01

    The micro-array profiling of micro-RNA has been performed in rat skeletal muscle tissues, isolated from male adult offspring of intrauterine plus postnatal growth restricted model (IPGR). Apparently, the GLUT4 mRNA expression in male sk. muscle was found to be unaltered in contrast to females. The over-expression of miR-29a and miR-23a in the experimental group of SMSP (Starved Mother Starved Pups) have been found to regulate the glucose transport activity with respect to their control counterparts CMCP (Control Mother Control Pups) as confirmed in rat L6 myoblast-myocyte cell culture system. The ex-vivo experimentation demonstrates an aberration in insulin signaling pathway in male sk. muscle that leads to the localization of the membrane-bound Glut4 protein. We have identified through a series of experiments one important protein factor SMAD4, a co-SMAD critical to the TGF-beta signaling pathway. This factor is targeted by miR-29a, as identified in an in vitro reporter-assay system in cell-culture experiment. The other micro-RNA, miR-23a, targets SMAD4 indirectly that seems to be critical in regulating insulin-dependent glucose transport activity. MicroRNA mimics, inhibitors and siRNA studies indicate the role of SMAD4 as inhibitory for glucose transport activities in normal physiological condition. The data demonstrate for the first time a critical function of microRNAs in fine-tuning the regulation of glucose transport in skeletal muscle. Chronic starved conditions (IPGR) in sk. muscle up-regulates microRNA changing the target protein expression patterns, such as SMAD4, to alter the glucose transport pathways for the survival. The innovative outcome of this paper identifies a critical pathway (TGF-beta) that may act negatively for the mammalian glucose transport machinery.

  13. MicroRNA-206 colocalizes with ribosome-rich regions in both the nucleolus and cytoplasm of rat myogenic cells.

    Science.gov (United States)

    Politz, Joan C Ritland; Zhang, Fan; Pederson, Thoru

    2006-12-12

    MicroRNAs are small, approximately 21- to 24-nt RNAs that have been found to regulate gene expression. miR-206 is a microRNA that is expressed at high levels in Drosophila, zebrafish, and mouse skeletal muscle and is thought to be involved in the attainment and/or maintenance of the differentiated state. We used locked nucleic acid probes for in situ hybridization analysis of the intracellular localization of miR-206 during differentiation of rat myogenic cells. Like most microRNAs, which are presumed to suppress translation of target mRNAs, we found that miR-206 occupies a cytoplasmic location in cultured myoblasts and differentiated myotubes and that its level increases in myotubes over the course of differentiation, consistent with previous findings in muscle tissue in vivo. However, to our surprise, we also observed miR-206 to be concentrated in nucleoli. A probe designed to be complementary to the precursor forms of miR-206 gave no nucleolar signal. We characterized the intracellular localization of miR-206 at higher spatial resolution and found that a substantial fraction colocalizes with 28S rRNA in both the cytoplasm and the nucleolus. miR-206 is not concentrated in either the fibrillar centers of the nucleolus or the dense fibrillar component, where ribosomal RNA transcription and early processing occur, but rather is localized in the granular component, the region of the nucleolus where final ribosome assembly takes place. These results suggest that miR-206 may associate both with nascent ribosomes in the nucleolus and with exported, functional ribosomes in the cytoplasm.

  14. Laughing rats are optimistic.

    Directory of Open Access Journals (Sweden)

    Rafal Rygula

    Full Text Available Emotions can bias human decisions- for example depressed or anxious people tend to make pessimistic judgements while those in positive affective states are often more optimistic. Several studies have reported that affect contingent judgement biases can also be produced in animals. The animals, however, cannot self-report; therefore, the valence of their emotions, to date, could only be assumed. Here we present the results of an experiment where the affect-contingent judgement bias has been produced by objectively measured positive emotions. We trained rats in operant Skinner boxes to press one lever in response to one tone to receive a food reward and to press another lever in response to a different tone to avoid punishment by electric foot shock. After attaining a stable level of discrimination performance, the animals were subjected to either handling or playful, experimenter-administered manual stimulation - tickling. This procedure has been confirmed to induce a positive affective state in rats, and the 50-kHz ultrasonic vocalisations (rat laughter emitted by animals in response to tickling have been postulated to index positive emotions akin to human joy. During the tickling and handling sessions, the numbers of emitted high-frequency 50-kHz calls were scored. Immediately after tickling or handling, the animals were tested for their responses to a tone of intermediate frequency, and the pattern of their responses to this ambiguous cue was taken as an indicator of the animals' optimism. Our findings indicate that tickling induced positive emotions which are directly indexed in rats by laughter, can make animals more optimistic. We demonstrate for the first time a link between the directly measured positive affective state and decision making under uncertainty in an animal model. We also introduce innovative tandem-approach for studying emotional-cognitive interplay in animals, which may be of great value for understanding the emotional

  15. Electroejaculation of chimeric rats

    OpenAIRE

    McCoy, Marina R.; Montonye, Daniel; Bryda, Elizabeth C.

    2013-01-01

    With the advent of genetic engineering of rodents came the need to assess fertility and germline competency, especially in chimeric rodents generated using embryonic stem cells. Traditional methods rely on natural mating and progeny testing, which is time- and cost-intensive. Electroejaculation is a faster method of collecting sperm for genetic analysis and offers the additional benefit of using fewer animals. This column describes a refined electroejaculation technique for chimeric rats usin...

  16. Gravitational Biology: The Rat Model

    Science.gov (United States)

    1997-01-01

    In this session, Session JP3, the discussion focuses on the following topics: Morphology of brain, pituitary and thyroid in the rats exposed to altered gravity; Biochemical Properties of B Adrenoceptors After Spaceflight (LMS-STS78) or Hindlimb Suspension in Rats; Influence of Hypergravity on the Development of Monoaminergic Systems in the Rat Spinal Cord; A Vestibular Evoked Potentials (VsEPs) Study of the Function of the Otolith Organs in Different Head Orientations with respect to Earth Gravity Vector in the Rat; Quantitative Observations on the Structure of Selected Proprioceptive Components in Adult Rats that Underwent About Half of their Fetal Development in Space; Effects of a Nine-Day Shuttle Mission on the Development of the Neonatal Rat Nervous System, A Behavioral Study; Muscle Atrophy Associated to Microgravity in Rat, Basic Data For Countermeasures; Simulated Weightlessness by Unloading in the Rat, Results of a Time Course Study of Biochemical Events Occurring During Unloading and Lack of Effect of a rhBNP-2 Treatment on Bone Formation and Bone Mineral Content in Unloading Rats; and Cytological Mechanism of the Osteogenesis Under Microgravity Conditions.

  17. Generation of Hprt-disrupted rat through mouse←rat ES chimeras

    OpenAIRE

    Ayako Isotani; Kazuo Yamagata; Masaru Okabe; Masahito Ikawa

    2016-01-01

    We established rat embryonic stem (ES) cell lines from a double transgenic rat line which harbours CAG-GFP for ubiquitous expression of GFP in somatic cells and Acr3-EGFP for expression in sperm (green body and green sperm: GBGS rat). By injecting the GBGS rat ES cells into mouse blastocysts and transplanting them into pseudopregnant mice, rat spermatozoa were produced in mouse?rat ES chimeras. Rat spermatozoa from the chimeric testis were able to fertilize eggs by testicular sperm extraction...

  18. model in female wistar rats

    African Journals Online (AJOL)

    2013-12-31

    Dec 31, 2013 ... cyclodextrin on wister rats : histopathologic analoges. Fundan Clin. Pharmacol.; 23(6) :747-755. Sandor, V., Cuparencu, B., Dumitrascu, L.D., Birt, A.M. and Krausz, L.T. (2006). Protective effects of amphetamine on gastric ulcerations induced by indomethacin in rats. World J. Gastroenterol.; 12(44): ...

  19. Do rats have orgasms?

    Directory of Open Access Journals (Sweden)

    James G. Pfaus

    2016-10-01

    Full Text Available Background: Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method: Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs in other species: 1 physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2 short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3 long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results: Both male and female rats display behavioral patterns consistent with OLRs. Conclusions: The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research.

  20. Do rats have orgasms?

    Science.gov (United States)

    Pfaus, James G; Scardochio, Tina; Parada, Mayte; Gerson, Christine; Quintana, Gonzalo R; Coria-Avila, Genaro A

    2016-01-01

    Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs) in other species: 1) physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2) short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3) long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Both male and female rats display behavioral patterns consistent with OLRs. The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research.

  1. Do rats have orgasms?

    Science.gov (United States)

    Pfaus, James G.; Scardochio, Tina; Parada, Mayte; Gerson, Christine; Quintana, Gonzalo R.; Coria-Avila, Genaro A.

    2016-01-01

    Background Although humans experience orgasms with a degree of statistical regularity, they remain among the most enigmatic of sexual responses; difficult to define and even more difficult to study empirically. The question of whether animals experience orgasms is hampered by similar lack of definition and the additional necessity of making inferences from behavioral responses. Method Here we define three behavioral criteria, based on dimensions of the subjective experience of human orgasms described by Mah and Binik, to infer orgasm-like responses (OLRs) in other species: 1) physiological criteria that include pelvic floor and anal muscle contractions that stimulate seminal emission and/or ejaculation in the male, or that stimulate uterine and cervical contractions in the female; 2) short-term behavioral changes that reflect immediate awareness of a pleasurable hedonic reward state during copulation; and 3) long-term behavioral changes that depend on the reward state induced by the OLR, including sexual satiety, the strengthening of patterns of sexual arousal and desire in subsequent copulations, and the generation of conditioned place and partner preferences for contextual and partner-related cues associated with the reward state. We then examine whether physiological and behavioral data from observations of male and female rats during copulation, and in sexually-conditioned place- and partner-preference paradigms, are consistent with these criteria. Results Both male and female rats display behavioral patterns consistent with OLRs. Conclusions The ability to infer OLRs in rats offers new possibilities to study the phenomenon in neurobiological and molecular detail, and to provide both comparative and translational perspectives that would be useful for both basic and clinical research. PMID:27799081

  2. Electroejaculation of chimeric rats.

    Science.gov (United States)

    McCoy, Marina R; Montonye, Daniel; Bryda, Elizabeth C

    2013-06-01

    With the advent of genetic engineering of rodents came the need to assess fertility and germline competency, especially in chimeric rodents generated using embryonic stem cells. Traditional methods rely on natural mating and progeny testing, which is time- and cost-intensive. Electroejaculation is a faster method of collecting sperm for genetic analysis and offers the additional benefit of using fewer animals. This column describes a refined electroejaculation technique for chimeric rats using light gas anesthesia and a custom-made platform for sperm collection.

  3. Serum testosterone concentration in chloroquine- treated rats ...

    African Journals Online (AJOL)

    ONOS

    2010-07-05

    Jul 5, 2010 ... The effects of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) were studied on serum testosterone concentration in chloroquine-treated rats. Thirty five (35) adult male rats weighing 160 - 200 g were divided into seven groups of five (5) rats each. Group I rats served as the control and received 2.

  4. Serum testosterone concentration in chloroquinetreated rats: effects ...

    African Journals Online (AJOL)

    The effects of ascorbic acid (vitamin C) and alpha-tocopherol (vitamin E) were studied on serum testosterone concentration in chloroquine-treated rats. Thirty five (35) adult male rats weighing 160 - 200 g were divided into seven groups of five (5) rats each. Group I rats served as the control and received 2 ml/kg of normal ...

  5. Down-regulation of microRNA-184 contributes to the development of cyanotic congenital heart diseases.

    Science.gov (United States)

    Huang, Jiancheng; Li, Xiaobing; Li, Hongying; Su, Zhenyu; Wang, Jun; Zhang, Huijun

    2015-01-01

    We aimed to investigate the roles of miR-184 in adaptation of hypoxic cardiomyocytes, as well as to elucidate the possible mechanisms of miR-184 in the development of cyanotic congenital heart diseases (CHD). We conducted quantitative real-time polymerase chain reaction (qRT-PCR) to determine the expression of miR-184 in patients with cyanotic cardiac defects. The embryonic rat ventricular myocardial H9c2 cells were transfected with miR-184 inhibitor and negative scramble RNA. Mock group was untreated by anything. We then used MTT assay and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) to determine whether inhibition of miR-184 in vitro affect cell proliferation and apoptosis under hypoxic conditions. Besides, the expression levels of caspase-3 and caspase-9 in hypoxic H9c2 cells were determined by western blot. MiR-184 was significantly down-regulated in CHD patients with cyanotic cardiac defects. In addition, miR-184 was successfully inhibited in hypoxic H9c2 cells. Moreover, inhibition of miR-184 markedly decreased cell viability and obviously induced apoptosis under hypoxic conditions in vitro. Besides, the expression levels of caspase-3 and caspase-9 in hypoxic H9c2 were significantly increased after miR-184 inhibition. Our findings indicate that inhibition of microRNA-184 may contribute to the development of cyanotic CHD via decreasing proliferation and inducing apoptosis of cardiomyocytes. Moreover, miR-184 inhibition may promote hypoxia-induced apoptosis via activation of caspase-3 and caspase-9. Congenital down-regulation of miR-184 may be a mechanism leading to CHD development.

  6. PENICILLIN EPILEPSY IN RATS

    Directory of Open Access Journals (Sweden)

    Voja Pavlović

    2004-12-01

    Full Text Available The purpose of this study is to test, in a model of experimental penicillin epilepsy, a hypothesis of primary and dominant role of cortex in genesis of epileptic discharges, by using recordings of electrocorticograms (EcoG. The experiments were made with around two and a half old male rats. The rats were divided into four groups of five animals each. In the case of the first group, antibiotics were applied intraperitoneally (i.p.. Epileptic generalized discharges of this group were not registered until administering a dosage of antibiotics higher than 1.8 x 106 IU/kg. In the second group, application of a dosage of 1.2 x 106 IU/kg resulted in individual discharges. In the third group, antibiotics were applied intracortically (i.c. in a dosage of 50 IU and caused individual discharges without big seizures. The fourth group needed a dosage of 100 IU/kg of penicillin applied i.c. to develop a big seizure. Discharges in the first three groups were registered first as unilateral with a subsequent development of bilateral synchrony. In the case of the fourth group, immediately and abruptly after the application of penicillin big seizures developed violently and repeated several times. We consider that the very implantation of electrodes provokes occurrence of discharging.

  7. The Rat Race

    CERN Multimedia

    Stephen Haywood

    Dear Muriel, Being an animal, you are probably more familiar with rats than most of us. Yet it seems to me that our Community (not just ATLAS) is stuck in a huge "rat race". I am somewhat mystified as to how we have got ourselves into this and I wonder whether you or your readers could explain this - I give my own observations below. In HEP and ATLAS specifically, we are all working long hours and we are all becoming exhausted. There are people at Point 1 who are working day and night, every day of the week; there are people writing software who send emails round the clock, including weekends. It is one thing to have bursts of activity which require us to put in some longer hours, but in ATLAS, the bursts last months or years. I have been on ATLAS 14 years and it has felt like one endless rush. Why do we do this? We are all highly motivated, we love our work and want to succeed individually and collectively. We are parts of various teams, and we do not want to let the side down. We worked hard at school an...

  8. Postural development in rats.

    Science.gov (United States)

    Lelard, T; Jamon, M; Gasc, J-P; Vidal, P-P

    2006-11-01

    Mammals adopt a limited number of postures during their day-to-day activities. These stereotyped skeletal configurations are functionally adequate and limit the number of degrees of freedom to be controlled by the central nervous system. The temporal pattern of emergence of these configurations in altricial mammals is unknown. We therefore carried out an X-ray study in unrestrained rats from birth (P0) until postnatal day 23 (P23). The X-rays showed that many of the skeletal configurations described in adult rodents were already present at birth. By contrast, limb placement changed abruptly at around P10. These skeletal configurations, observed in anesthetized pups, required the maintenance of precise motor control. On the other hand, motor control continued to mature, as shown by progressive changes in resting posture and head movements from P0 to P23. We suggest that a few innate skeletal configurations provide the necessary frames of reference for the gradual construction of an adult motor repertoire in altricial mammals, such as the rat. The apparent absence of a requirement for external sensorial cues in the maturation of this repertoire may account for the maturation of postural and motor control in utero in precocial mammals (Muir et al., 2000 for a review on the locomotor behavior of altricial and precocial animals).

  9. Oxidative Stress in Aged Rats

    Directory of Open Access Journals (Sweden)

    Damisela Ramírez Ramírez

    2013-12-01

    Full Text Available Background: aging is one of the major problems that the world is facing today due to its impact on all areas of society. Objective: to determine the concentrations of advanced oxidation protein products and malondialdehyde as indicators of oxidative damage and to determine the antioxidant defense capacity of the enzymes superoxide dismutase, catalase and the reduced glutathione concentration in aged rats. Methods: a total of 20 male Wistar rats with a body weight of approximately 200 to 250 grams were selected to form two groups with 10 young adult rats and 10 old rats. 2 ml of blood was drawn from the paranasal sinus. The sample was collected in 5 ml vials and after being homogenized, it was sent to the Biomedical Research Center, where it was used to assess the following oxidative stress variables: degree of oxidative damage and antioxidant defense level. An analysis of variance was performed to study the behavior of the different groups. Differences were considered significant when P value was less than 0.05. Results: no significant changes were found in the concentrations of malondialdehyde and glutathione, as well as in the superoxide dismutase and catalase activity in aged rats compared to young. Concentration of advanced oxidation protein products increased significantly in aged rats. Conclusions: aged rats showed an increase in oxidative damage to proteins. Antioxidant defense capacity of the enzymes superoxide dismutase and catalase and reduced glutathione concentration showed no changes.

  10. Rat traps: filling the toolbox for manipulating the rat genome

    NARCIS (Netherlands)

    van Boxtel, R.; Cuppen, E.

    2010-01-01

    The laboratory rat is rapidly gaining momentum as a mammalian genetic model organism. Although traditional forward genetic approaches are well established, recent technological developments have enabled efficient gene targeting and mutant generation. Here we outline the current status, possibilities

  11. Population Structure of Rat-Derived Pneumocystis carinii in Danish Wild Rats

    DEFF Research Database (Denmark)

    Palmer, Robert J.; Settnes, Osvald P.; Lodal, Jens

    2000-01-01

    The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P. cari...

  12. TRANSFER OF A RESPONSE TO NAIVE RATS BY INJECTION OF RIBONUCLEIC ACID EXTRACTED FROM TRAINED RATS.

    Science.gov (United States)

    BABICH, F R; JACOBSON, A L; BUBASH, S; JACOBSON, A

    1965-08-06

    Rats were trained in a Skinner box to approach the food cup when a distinct click was sounded. Ribonucleic acid was extracted from the brains of these rats and injected into untrained rats. The untrained rats then manifested a significant tendency (as compared with controls) to approach the food cup when the click, unaccompanied by food, was presented.

  13. Whey Protein Concentrate and Dexamethasone Protected Rat ...

    African Journals Online (AJOL)

    Dr Olaleye

    ABSTRACT. The possible radioprotective effect of Immunocal® (whey protein]) supplement and dexamethasone on gamma-irradiated cerebellar tissue of Wistar rat was investigated in this study. Forty male albino rats were acclimatized and randomized into four groups of 10 animals each. Group I rats served as control; ...

  14. seed on haematological parameters of albino rats

    African Journals Online (AJOL)

    Dr Ejere

    2015-06-23

    Jun 23, 2015 ... albino rats (Rattus novergicus). Ejere, Vincent C.*, Ugwu, Godwin C., Chukwuka, Christian O. and Nnamonu, Emmanuel I. ... Similarly, lectin from M. sloanei has been reported as an effective and suitable cell ... male albino rats were then assigned into four groups (A, B, C, and. D) of 12 rats per group.

  15. The serotonin transporter knockout rat : A review

    NARCIS (Netherlands)

    Olivier, Jocelien; Cools, Alexander; Ellenbroek, Bart A.; Cuppen, E.; Homberg, Judith; Kalueff, Allan V.; LaPorte, Justin L.

    2010-01-01

    This chapter dicusses the most recent data on the serotonin transporter knock-out rat, a unique rat model that has been generated by target-selected N-ethyl-N-nitrosourea (ENU) driven mutagenesis. The knock-out rat is the result of a premature stopcodon in the serotonin transporter gene, and the

  16. Tuberculosis Detection by Giant African Pouched Rats

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

    2011-01-01

    In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

  17. Whey protein concentrate and dexamethasone protected rat ...

    African Journals Online (AJOL)

    The possible radioprotective effect of Immunocal® (whey protein]) supplement and dexamethasone on gamma-irradiated cerebellar tissue of Wistar rat was investigated in this study. Forty male albino rats were acclimatized and randomized into four groups of 10 animals each. Group I rats served as control; Group II: ...

  18. Chronic study on BHT in rats

    DEFF Research Database (Denmark)

    Würtzen, G.; Olsen, P.

    1986-01-01

    Groups of 40, 29, 39 and 44 F0 rats of each sex were fed a semi-synthetic diet containing butylated hydroxytoluene (BHT) in concentrations to provide intakes of 0, 25, 100 or 500 mg/kg body weight/day, respectively. The F0 rats were mated, and groups of 100, 80, 80 and 100 F1 rats of each sex wer...

  19. Rat penis as a replantation model.

    Science.gov (United States)

    Karamürsel, Sebat; Karamürsel, Tamer; Celebioğlu, Selim

    2005-11-01

    The aim of this study is to assess the feasibility of rat penile replantation as a new microsurgical training model. The study was performed in 2 parts. ANATOMIC STUDIES: Fifteen Wistar albino rats were used to study and document the penile vascular anatomy. In 5 rats, dissections were performed after colored silicone injections, while 5 rats were operated under anesthesia to develop the strategy of flap elevation. In the remaining 5 rats, microangiographic study was performed with silicone-lead oxide mixture. FLAP STUDIES: As flap studies in 5 rats, penis were elevated based on right-side internal pudendal artery and internal pudendal vein and resutured. In 6 rats, penis were elevated as free flaps, and in 3 rats the penis were implanted in right thigh of the rats being the femoral artery and vein recipient. In the remaining 3 rats, penis were resutured in their original place, with saphenous artery and vein being the recipient and rerouted to the pubic region. At postoperative fifth day, the penis were examined for viability, and selected ones were histologically examined. Rat penis has a dual blood supply from bilateral internal pudendal arteries. Venous drainage is via both crural veins and dorsal vein. One side of the internal pudendal artery and anastomotic vein (branch of pudendal plexus) may be used as the vascular pedicle of the flap. Rat penis may be successfully elevated as a free flap and also may be replanted in its original place.

  20. Sleep in spontaneous dwarf rats.

    Science.gov (United States)

    Peterfi, Zoltan; Obal, Ferenc; Taishi, Ping; Gardi, Janos; Kacsoh, Balint; Unterman, Terry; Krueger, James M

    2006-09-07

    Spontaneous dwarf rats (SDRs) display growth hormone (GH) deficiency due to a mutation in the GH gene. This study investigated sleep in SDRs and their somatotropic axis and compared to Sprague-Dawley rats. SDRs had almost undetectable levels of plasma GH. Hypothalamic GH-releasing hormone (GHRH) mRNA was increased, whereas GHRH-receptor (GHRH-R) and somatostatin mRNAs were decreased in SDRs. Hypothalamic GHRH and somatostatin peptide content decreased in SDRs. Quantitative immunohistochemistry for GHRH and GHRH-R corroborated and extended these findings. In the arcuate nucleus, the number of GHRH-positive cells was significantly higher, whereas GHRH-R-positive perikarya were diminished in SDRs. Cortical GHRH and GHRH-R measurements showed similar expression characteristics as those found in the hypothalamus. SDRs had less rapid eye movement sleep (REMS) and more non-REMS (NREMS) than the control rats during the light period. The electroencephalogram (EEG) delta and theta power decreased during NREMS in the SDRs. After 4-h of sleep deprivation, SDRs had a significantly reduced REMS rebound compared to the controls, whereas NREMS rebound was normal in SDRs. The enhancement in delta power was significantly less than in the control group during recovery sleep. Intracerebroventricular (icv) administration of GHRH promoted NREMS in both strains of rats; however, increased REMS and EEG delta activity was observed only in control rats. Icv injection of insulin-like growth factor 1 increased NREMS in control rats, but not in the SDRs. These results support the ideas that GHRH is involved in NREMS regulation and that GH is involved in the regulation of REMS and in EEG slow wave activity regulation during NREMS.

  1. Voluntary Sleep Loss in Rats

    Science.gov (United States)

    Oonk, Marcella; Krueger, James M.; Davis, Christopher J.

    2016-01-01

    Study Objectives: Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Methods: Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. Results: After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. Conclusions: We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. Citation: Oonk M, Krueger JM, Davis CJ. Voluntary sleep loss in rats. SLEEP 2016;39(7):1467–1479. PMID:27166236

  2. A Focused Microarray for Screening Rat Embryonic Stem Cell Lines

    OpenAIRE

    Hong, James; He, Hong; Bui, Phuoc; Ryba-White, Ben; Rumi, Mohammad A.K.; Soares, Michael J.; Dutta, Debasree; Paul, Soumen; Kawamata, Masaki; Ochiya, Takahiro; Ying, Qi-Long; Rajanahalli, Pavan; Mark L. Weiss

    2012-01-01

    Here, we describe a focused microarray for screening rat embryonic stem cells (ESCs) and provide validation data that this array can distinguish undifferentiated rat ESCs from rat trophoblast stem (TS) cells, rat extraembryonic endoderm cells, mouse embryonic fibroblast feeder cells, and differentiated rat ESCs. Using this tool, genuine rat ESC lines, which have been expanded in a conventional rat ESC medium containing two inhibitors (2i), for example, glycogen synthase kinase 3 (GSK3) and mi...

  3. Swimming-based pica in rats.

    Science.gov (United States)

    Nakajima, Sadahiko

    2016-09-01

    We have recently demonstrated that voluntary or forced running in activity wheels yields pica behavior (kaolin clay intake) in rats (Nakajima, 2016; Nakajima and Katayama, 2014). The present study provides experimental evidence that a single 40-min session of swimming in water also generates pica in rats, while showering rats with water does not produce such behavior. Because kaolin intake has been regarded as a measure of nausea in rats, this finding suggests that swimming activity, as well as voluntary or forced running, induces nausea in rats. Copyright © 2016. Published by Elsevier B.V.

  4. Susceptibility of laboratory rats against genotypes 1, 3, 4, and rat hepatitis E viruses.

    Science.gov (United States)

    Li, Tian-Cheng; Yoshizaki, Sayaka; Ami, Yasushi; Suzaki, Yuriko; Yasuda, Shumpei P; Yoshimatsu, Kumiko; Arikawa, Jiro; Takeda, Naokazu; Wakita, Takaji

    2013-04-12

    To determine whether or not rats are susceptible to hepatitis E virus (HEV) infection, each of group containing three laboratory rats (Wistar) were experimentally inoculated with genotypes 1, 3, 4 and rat HEV by intravenous injection. Serum and stool samples were collected and used to detect HEV RNA and anti-HEV antibodies by RT-PCR and ELISA, respectively. The virus infection was monitored up to 3 months after inoculation. None of the serum or stool samples collected from the rats inoculated with G1, G3, or G4 HEV indicated positive sign for virus replication. Although no alteration was observed in ALT level, rat HEV RNA was detected in stools from both of the rats inoculated with rat HEV, and both rats were positive for anti-rat HEV IgG and IgM from 3 weeks after inoculation. These results demonstrated that rats are susceptible to rat HEV but not to G1, G3, and G4 HEV. We also confirm that the nude rats were useful for obtaining a large amount of rat HEV and that the rat HEV was transmitted by the fecal-oral route. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Immunochemistry of Rat Lung Tumorigenesis

    Science.gov (United States)

    1983-01-01

    3 * f.*. b; 3 - .’ • ~ -•. -. 3 *. 3 . , . 3• • . .• . • used in this set of experiments. Animals were anesthetized with methoxyflurane and...by supplying methoxyflurane to the rats’ noses in a small plastic funnel. The surgery consisted of making a small slit in the neck and injecting the

  6. wheat flour (dubbie) in rats

    African Journals Online (AJOL)

    2 Central Food Technological Research Institute. Mysore 570013, Mysore, India. ABSTRACT: Anaemic rats were fed on diets containing sour dough bread. (Di/'0 dabbo) or porridge prepared from soy-fortified wheat flour (Dubbie) as the source of nonheme iron. The criteria used to determine the relative biological.

  7. CCl4 cirrhosis in rats

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

    1991-01-01

    Cirrhosis of the rat liver was induced by a 12 week individualized CCl4/phenobarbital treatment. After treatment, all surviving animals (81%) showed cirrhosis of the liver. The cirrhosis induced was irreversible when evaluated 24 weeks after cessation of treatment. Quantitative liver function...

  8. Tubuloglomerular feedback in Dahl rats

    DEFF Research Database (Denmark)

    Karlsen, F M; Leyssac, P P; Holstein-Rathlou, N H

    1998-01-01

    We have previously demonstrated a loss of autoregulation in Dahl salt-sensitive (Dahl-S) rats rendered hypertensive on a high-salt diet. To determine whether this was due to a decreased activity of either the myogenic or the tubuloglomerular feedback (TGF) response, we tested the TGF response...

  9. The rat GPRC6A

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Burhenne, Nicole; Christiansen, Bolette

    2007-01-01

    GPRC6A is a novel member of family C of G protein-coupled receptors with so far elusive biological function. GPRC6A has been described in human and mouse as a promiscuous l-alpha-amino acid receptor. We now report the cloning, expression analysis and, functional characterization of the rat orthol...

  10. induced hepatic injury in rats

    African Journals Online (AJOL)

    Toxicological evaluation of Thymelaea hirsuta and protective effect against CCl 4 -induced hepatic injury in rats. ... There were no significant differences in red blood cells count (p<0.05), in Hemoglobin and Hematocrit serum levels but a significant increase in white blood cells count (p<0.001) and in platelets (p< 0.05) for all ...

  11. ideal hepatotoxicity model in rats using carbon tetrachloride (ccl4)

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. A study to produce ideal Hepatotoxicity rats' models using varying concentrations of carbon tetrachloride (CCl4) was carried out. A total of seventy five rats were divided into five (5) groups of twenty five (25) rats each; rats in group I are negative control, were not induced with lipid peroxidation. Rats in groups II, ...

  12. Voluntary Sleep Loss in Rats.

    Science.gov (United States)

    Oonk, Marcella; Krueger, James M; Davis, Christopher J

    2016-07-01

    Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. © 2016 Associated Professional Sleep Societies, LLC.

  13. Kangaroo rat bone compared to white rat bone after short-term disuse and exercise

    Science.gov (United States)

    Muths, E.; Reichman, O. J.

    1996-01-01

    Kangaroo rats (Dipodomys ordii) were used to study the effects of confinement on mechanical properties of bone with a long range objective of proposing an alternative to the white rat model for the study of disuse osteoporosis. Kangaroo rats exhibit bipedal locomotion, which subjects their limbs to substantial accelerative forces in addition to the normal stress of weight bearing. We subjected groups of kangaroo rats and white rats (Rattus norvegicus) to one of two confinement treatments or to an exercise regime; animals were exercised at a rate calculated to replicate their (respective) daily exercise patterns. White laboratory rats were used as the comparison because they are currently the accepted model used in the study of disuse osteoporosis. After 6 weeks of treatment, rats were killed and the long bones of their hind limbs were tested mechanically and examined for histomorphometric changes. We found that kangaroo rats held in confinement had less ash content in their hind limbs than exercised kangaroo rats. In general, treated kangaroo rats showed morphometric and mechanical bone deterioration compared to controls and exercised kangaroo rats appeared to have slightly “stronger” bones than confined animals. White rats exhibited no significant differences between treatments. These preliminary results suggest that kangaroo rats may be an effective model in the study of disuse osteoporosis.

  14. Advances on genetic rat models of epilepsy

    Science.gov (United States)

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoto, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2014-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: ‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies. PMID:25312505

  15. Advances on genetic rat models of epilepsy.

    Science.gov (United States)

    Serikawa, Tadao; Mashimo, Tomoji; Kuramoro, Takashi; Voigt, Birger; Ohno, Yukihiro; Sasa, Masashi

    2015-01-01

    Considering the suitability of laboratory rats in epilepsy research, we and other groups have been developing genetic models of epilepsy in this species. After epileptic rats or seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits were usually genetically-fixed by selective breeding. So far, the absence seizure models GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER have been established. Dissection of the genetic bases including causative genes in these epileptic rat models would be a significant step toward understanding epileptogenesis. N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type 1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea (MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2 (EA2) model rats. Thus, epileptic rat models have been established on the two paths: 'phenotype to gene' and 'gene to phenotype'. In the near future, development of novel epileptic rat models will be extensively promoted by the use of sophisticated genome editing technologies.

  16. Sevoflurane-induced pica in female rats.

    Science.gov (United States)

    Yamamoto, Kouichi; Yamamoto, Emiri; Sugimoto, Toru; Sagakami, Takuya; Yamatodani, Atsushi

    2016-05-01

    We examined the effects of volatile anesthetics on pica, which can be used to assess nausea and vomiting in rats. We found that inhalation anesthesia with sevoflurane significantly induced pica in female but not male rats. Among the female rats, young rats (8 weeks old) were more susceptible to its induction than adult rats (20 weeks old) with ovariectomy or sham-surgery. Anti-emetic drugs that are used to prevent postoperative nausea and vomiting (PONV) inhibited the pica. These results suggest that sevoflurane-induced pica in young female rats has the potential to be an animal model of PONV in humans. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  17. Cardiovascular end-organ damage in Ren-2 transgenic rats compared to spontaneously hypertensive rats

    NARCIS (Netherlands)

    Pinto, YM; Buikema, H; vanGilst, WH; vanGeel, PP; deGraeff, PA; Wagner, J; Paul, M

    To compare hypertensive end-organ damage in two genetic forms of hypertension we assessed cardiovascular function in two rat strains of generic hypertension: transgenic rats overexpressing the mouse Ren-2 gene [(TGR(mREN2)27]) and blood pressure matched spontaneously hypertensive rats (SHR). Despite

  18. Unraveling the Obesity of OLETF Rats

    OpenAIRE

    Moran, Timothy H.

    2007-01-01

    Cholecystokinin (CCK) is a brain gut peptide that plays an important role in satiety. CCK inhibits food intake by reducing meal size. CCK’s satiety actions are mediating through its interaction with CCK1 receptors. Otsuka Long Evans Tokushima Fatty (OLETF) rats are a CCK1 receptor knockout model that allows the study of multiple CCK functions. OLETF rats are hyperphagic with the hyperphagia expressed as a significant increase in the size of meals. OLETF rat obesity is secondary to the hyperph...

  19. The thymus reconstituted nude rat

    DEFF Research Database (Denmark)

    Hougen, H P; Klausen, B

    1987-01-01

    The monoclonal antibodies OX6, OX19, W3/13, OX7, OX8, and W3/25 were used to gain information about the distribution of different lymphocyte subpopulations in peripheral lymphoid organs of neonatally isogeneic and allogeneic thymus reconstituted nude rats. Splenic mitogen responsiveness, xenogeneic...... skin rejection, and antibody titers were also measured in the same groups of animals. The experiments showed that both allogeneic and isogeneic thymus grafting cause a significant amplification of cells in the different T lymphocyte subpopulations. The functional tests, however, indicate that the T...... cell response is far better following isografting. We, therefore, conclude that isogeneic thymus grafting is an easy method of reconstituting the nude rat immunologically....

  20. Isolation of rat adrenocortical mitochondria

    Energy Technology Data Exchange (ETDEWEB)

    Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

  1. Phosphodiesterases in the rat ovary

    DEFF Research Database (Denmark)

    Petersen, Tonny Studsgaard; Stahlhut, Martin; Andersen, Claus Yding

    2015-01-01

    Phosphodiesterases (PDEs) are important regulators of the intracellular cAMP concentration, which is a central second messenger that affects a multitude of intracellular functions. In the ovaries, cAMP exerts diverse functions, including regulation of ovulation and it has been suggested...... that augmented cAMP levels stimulate primordial follicle growth. The present study examined the gene expression, enzyme activity and immunolocalization of the different cAMP hydrolysing PDEs families in the rat ovary. Further, the effect of PDE4 inhibition on primordial follicle activation in cultured neonatal...... rat ovaries was also evaluated. We found varied expression of all eight families in the ovary with Pde7b and Pde8a having the highest expression each accounting for more than 20% of the total PDE mRNA. PDE4 accounted for 15-26% of the total PDE activity. Immunoreactive PDE11A was found in the oocytes...

  2. Dynamics of the skeletal muscle secretome during myoblast differentiation

    DEFF Research Database (Denmark)

    Henningsen, Jeanette; Rigbolt, Kristoffer T G; Blagoev, Blagoy

    2010-01-01

    of protein secretion. We identified and quantitatively analyzed 635 secreted proteins, including 35 growth factors, 40 cytokines, and 36 metallopeptidases. The extensive presence of these proteins that can act as potent signaling mediators to other cells and tissues strongly highlights the important role...... of the intracellular levels of members of the semaphorin family and their corresponding secretion dynamics demonstrated that the release of secreted proteins is tightly regulated by the secretory pathway, the stability of the protein, and/or the processing of secreted proteins. Finally, we provide 299 unique...

  3. Cellular Proteome Dynamics during Differentiation of Human Primary Myoblasts

    DEFF Research Database (Denmark)

    Le Bihan, Marie-Catherine; Barrio, Inigo; Mortensen, Tenna Pavia

    2015-01-01

    Muscle stem cells, or satellite cells, play an important role in the maintenance and repair of muscle tissue and have the capacity to proliferate and differentiate in response to physiological or environmental changes. Although they have been extensively studied, the key regulatory steps and the ......Muscle stem cells, or satellite cells, play an important role in the maintenance and repair of muscle tissue and have the capacity to proliferate and differentiate in response to physiological or environmental changes. Although they have been extensively studied, the key regulatory steps...... and the complex temporal protein dynamics accompanying the differentiation of primary human muscle cells remain poorly understood. Here, we demonstrate the advantages of applying a MS-based quantitative approach, stable isotope labeling by amino acids in cell culture (SILAC), for studying human myogenesis...... in vitro and characterize the fine-tuned changes in protein expression underlying the dramatic phenotypic conversion of primary mononucleated human muscle cells during in vitro differentiation to form multinucleated myotubes. Using an exclusively optimized triple encoding SILAC procedure, we generated...

  4. LIEER OF WISTAR RAT MODELS

    African Journals Online (AJOL)

    homeostasis synthesised in the liver, has been raised in cases of impaired liver. fimcflun. ... Bil rats served as co:|rtrols, while Eflmts more test animals. The .... between 13D-15tJg were used. These anin1alswe1'edividedlntotwo[2]n1eiJ1 groups: the control group and the test animals. Each group comprised sixty [60].

  5. Renal function in streptozotocin-diabetic rats

    DEFF Research Database (Denmark)

    Jensen, P K; Christiansen, J S; Steven, K

    1981-01-01

    Renal function was examined with micropuncture methods in the insulin-treated streptozotocin-diabetic rat. Kidney glomerular filtration rate was significantly higher in the diabetic rats (1.21 ml/min) than in the control group (0.84 ml/min) Nephron glomerular filtration rate increased in proportion...... to the rise in kidney glomerular filtration rate (diabetic rats: 37.0 nl/min; control rats: 27.9 nl/min). Likewise renal plasma flow was significantly higher in the diabetic rats (4.1 ml/min) than in the control group (3.0 ml/min). Glomerular capillary pressure was identical in both groups (56.0 and 56.0 mm......-1mmHg-1). Kidney weight was significantly higher in the diabetic rats (1.15 g; control rats: 0.96 g) while body weight was similar in both groups (diabetic rats: 232 g; control rats: 238 g). Calculations indicate that the increases in transglomerular hydraulic pressure, renal plasma flow...

  6. Automatic Training of Rat Cyborgs for Navigation

    Science.gov (United States)

    Yu, Yipeng; Wu, Zhaohui; Xu, Kedi; Gong, Yongyue; Zheng, Nenggan; Zheng, Xiaoxiang; Pan, Gang

    2016-01-01

    A rat cyborg system refers to a biological rat implanted with microelectrodes in its brain, via which the outer electrical stimuli can be delivered into the brain in vivo to control its behaviors. Rat cyborgs have various applications in emergency, such as search and rescue in disasters. Prior to a rat cyborg becoming controllable, a lot of effort is required to train it to adapt to the electrical stimuli. In this paper, we build a vision-based automatic training system for rat cyborgs to replace the time-consuming manual training procedure. A hierarchical framework is proposed to facilitate the colearning between rats and machines. In the framework, the behavioral states of a rat cyborg are visually sensed by a camera, a parameterized state machine is employed to model the training action transitions triggered by rat's behavioral states, and an adaptive adjustment policy is developed to adaptively adjust the stimulation intensity. The experimental results of three rat cyborgs prove the effectiveness of our system. To the best of our knowledge, this study is the first to tackle automatic training of animal cyborgs. PMID:27436999

  7. Hyperparathyroidism is augmented by ovariectomy in Nagase analbuminemic rats.

    Science.gov (United States)

    Inaba, M; Morii, H; Katsumata, T; Goto, H; Ishimura, E; Kawagishi, T; Kamao, M; Okano, T; Nishizawa, Y

    2000-06-01

    The role of albumin in bone metabolism was studied in Nagase analbuminemic (NA) rats. Serum calcium (Ca), inorganic phosphate (Pi) and magnesium (Mg) concentrations did not differ between female NA and control Sprague-Dawley (SD) rats at the time of ovariectomy (ovx), although serum ionized Ca was significantly lower in NA rats than in SD rats. Serum parathyroid hormone (PTH) and osteocalcin (OC) concentrations and urinary Ca excretion were significantly greater in NA rats than in SD rats, suggesting hyperparathyroidism and the resultant enhanced bone turnover in NA rats. Paradoxically, ovx increased serum PTH and OC in NA rats but not in SD rats. Ovx-induced exacerbation of hyperparathyroidism was confirmed by significantly greater conversion of 25-hydroxyvitamin D to 1, 25-dihydroxyvitamin D in ovx NA rats even after normalization to vitamin D-binding protein. Bone mineral density (BMD) in proximal tibia increased similarly in a time-dependent manner in sham-operated NA and SD rats. However, ovx ablated the time-dependent increase of BMD in SD rats and significantly decreased BMD in NA rats by 2 wk after ovx, resulting in a significantly lower BMD in ovx NA rats than in ovx SD rats. In summary, NA rats, which are analbuminemic with compensatory increases in lipid and protein synthesis, developed hyperparathyroidism, possibly due to an increase in serum Pi and a reduction of ionized Ca, and ovx induced a greater BMD reduction in NA rats than in SD rats, probably by exacerbating hyperparathyroidism.

  8. Stevia preferences in Wistar rats.

    Science.gov (United States)

    Núñez Martínez, Paula; Argüelles Luis, Juan; Perillán Méndez, Carmen

    2016-11-01

    The Stevia rebaudiana plant is likely to become a major source of high-potency sweetener for the growing natural-food market. S. rebaudiana is the source of a number of sweet diterpenoid glycosides, but the major sweet constituents are rebaudioside A and stevioside. These two constituents have similar pharmacokinetic and metabolic profiles in rats and humans, and thus, studies carried out with either steviol glycoside are relevant to both. Other studies illustrate the diversity of voluntary sweet intake in mammals. This study was done using a series of two-bottle tests that compared a wide range of sweetener concentrations versus saccharin concentrations and versus water. Wistar rats displayed preferences for stevia extract and pure rebaudioside A solutions over water at a range of concentrations (0.001% to 0.3%), and their intake peak occurred at 0.1% concentration. They also preferred solutions prepared with a commercial rebaudioside A plus erythritol mixture to water, and their peak was at 2% concentration. The present study provides new information about the responses of Wistar rats to stevia compounds and commercial stevia products such as Truvia. These results could help with the appropriate dosage selection for focused behavioral and physiological studies on stevia.

  9. Pathophysiology of the Belgrade Rat

    Directory of Open Access Journals (Sweden)

    Tania eVeuthey

    2014-04-01

    Full Text Available The Belgrade rat is an animal model of Divalent Metal Transporter-1 (DMT1 deficiency. This strain originates from an X-irradiation experiment first reported in 1966. Since then, the Belgrade rat’s pathophysiology has helped to reveal the importance of iron balance and the role of DMT1. This review discusses our current understanding of iron transport homeostasis and summarizes molecular details of DMT1 function. We describe how studies of the Belgrade rat have revealed key roles for DMT1 in iron distribution to red blood cells as well as duodenal iron absorption. The Belgrade rat’s pathology has extended our knowledge of hepatic iron handling, pulmonary and olfactory iron transport as well as brain iron uptake and renal iron handling. For example, relationships between iron and manganese metabolism have been discerned since both are essential metals transported by DMT1. Pathophysiologic features of the Belgrade rat provide us with a unique and interesting animal model to understand iron homeostasis.

  10. Microtubular stability affects pVHL-mediated regulation of HIF-1alpha via the p38/MAPK pathway in hypoxic cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Miao Teng

    Full Text Available BACKGROUND: Our previous research found that structural changes of the microtubule network influence glycolysis in cardiomyocytes by regulating the hypoxia-inducible factor (HIF-1α during the early stages of hypoxia. However, little is known about the underlying regulatory mechanism of the changes of HIF-1α caused by microtubule network alternation. The von Hippel-Lindau tumor suppressor protein (pVHL, as a ubiquitin ligase, is best understood as a negative regulator of HIF-1α. METHODOLOGY/PRINCIPAL FINDINGS: In primary rat cardiomyocytes and H9c2 cardiac cells, microtubule-stabilization was achieved by pretreating with paclitaxel or transfection of microtubule-associated protein 4 (MAP4 overexpression plasmids and microtubule-depolymerization was achieved by pretreating with colchicine or transfection of MAP4 siRNA before hypoxia treatment. Recombinant adenovirus vectors for overexpressing pVHL or silencing of pVHL expression were constructed and transfected in primary rat cardiomyocytes and H9c2 cells. With different microtubule-stabilizing and -depolymerizing treaments, we demonstrated that the protein levels of HIF-1α were down-regulated through overexpression of pVHL and were up-regulated through knockdown of pVHL in hypoxic cardiomyocytes. Importantly, microtubular structure breakdown activated p38/MAPK pathway, accompanied with the upregulation of pVHL. In coincidence, we found that SB203580, a p38/MAPK inhibitor decreased pVHL while MKK6 (Glu overexpression increased pVHL in the microtubule network altered-hypoxic cardiomyocytes and H9c2 cells. CONCLUSIONS/SIGNIFICANCE: This study suggests that pVHL plays an important role in the regulation of HIF-1α caused by the changes of microtubular structure and the p38/MAPK pathway participates in the process of pVHL change following microtubule network alteration in hypoxic cardiomyocytes.

  11. Costimulation and autoimmune diabetes in BB rats

    NARCIS (Netherlands)

    Beaudette-Zlatanova, BC; Whalen, B; Zipris, D; Yagita, H; Rozing, J; Groen, H; Benjamin, CD; Hunig, T; Drexhage, HA; Ansari, MJ; Leif, J; Mordes, JP; Greiner, DL; Sayegh, MH; Rossini, AA

    Costimulatory signals regulate T-cell activation. To investigate the role of costimulation in autoimmunity and transplantation, we studied the BB rat model of type 1 diabetes. Diabetes-prone BB (BBDP) rats spontaneously develop disease when 55-120 days of age. We observed that two anti-CD28

  12. THE GREATER CANE RATS (THRYONOMIS SWINDERIANUS,

    African Journals Online (AJOL)

    2017-01-12

    Jan 12, 2017 ... ABSTRACT. The adrenal glands of domesticated greater cane rats (Thryonomys swinderianus), were studied using histological and ultrastructural techniques. A total of seven (7) adult male greater cane rats, aged from 10-14 months, with an average weight of 1.89 kg (range: 1.6 -2.2 kg) were used in this ...

  13. Same-Different Categorization in Rats

    Science.gov (United States)

    Wasserman, Edward A.; Castro, Leyre; Freeman, John H.

    2012-01-01

    Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

  14. Experimental Salmonella typhimurium infections in rats. I

    DEFF Research Database (Denmark)

    Hougen, H P; Jensen, E T; Klausen, B

    1989-01-01

    The course of experimentally induced Salmonella typhimurium infection was studied in three groups of inbred LEW rats: homozygous +/+, athymic rnu/rnu and isogeneic thymus-grafted rnu/rnu rats. In the first experiment the animals were inoculated intraperitoneally with 10(8) bacteria and all animals...

  15. Bromsulphalein (BSP) clearance in ageing rats

    NARCIS (Netherlands)

    Hollander, C.F.; Leeuw-Israel, F.R. de; Arp-Neefjes, J.M.

    1968-01-01

    Liver function in ageing rats was studied, using the bromsulphalein (BSP) clearance test. The test was done on ultramicro scale. This made it possible to repeat the test several times in the same animal and to start a longitudinal study. In 3-month-old rats the BSP retentions, measured 15, 30 and 45

  16. Attachment in rat pups, an experimental approach

    NARCIS (Netherlands)

    Gispen, W.H.; Sigling, H.; Engeland, H. van; Spruijt, B.M.

    1998-01-01

    John Bowlby's attachment theory states that attachment behavior has been strengthened throughout evolution as a consequence of its adaptive value. We investigated the presence of attachment-like behavior in rat pups, by offering a choice between the home nest and a same aged other nest. Rat pups

  17. in Cardiac Muscles of Hemorrhagic Shocked Rats

    African Journals Online (AJOL)

    Purpose: To investigate the protective effects of various resuscitating fluids on severe hemorrhagic shocked (HS) rats by comparing the expression changes of hsp90α in cardiac muscles and survival of rats. Methods: Western-blot and immunohistochemistry methods were performed to determine hsp90á expressions in ...

  18. growing African giant rats Cricetomys gambianus

    African Journals Online (AJOL)

    Thermoregulation and evaporative water loss in growing African giant rats Cricetomys gambianus. M.H. Knight. Mammal Research Institute, University of Pretoria, Pretoria. With an increase in mass, weaned giant rat pups. Cricetomys gambianus, showed a corresponding decline in mass specific metabolism, conductance ...

  19. Training pouched rats to find people.

    Science.gov (United States)

    La Londe, Kate B; Mahoney, Amanda; Edwards, Timothy L; Cox, Christophe; Weetjens, Bart; Durgin, Amy; Poling, Alan

    2015-01-01

    Giant African pouched rats equipped with video cameras may be a tenable option for locating living humans trapped under debris from collapsed structures. In the present study, 5 pouched rats were trained to contact human targets in a simulated collapsed building and to return to the release point after hearing a signal to do so. During test sessions, each rat located human targets more often than it located similar-sized inanimate targets on which it had not previously been trained and spent more time within 1 m of the human target than within 1 m of the other targets. Overall, the rats found humans, plastic bags containing clothes, and plastic bags without clothes on 83%, 37%, and 11% of trials, respectively. These findings suggest that using pouched rats to search for survivors in collapsed structures merits further attention. © Society for the Experimental Analysis of Behavior.

  20. FoxO1 regulates myocardial glucose oxidation rates via transcriptional control of pyruvate dehydrogenase kinase 4 expression.

    Science.gov (United States)

    Gopal, Keshav; Saleme, Bruno; Al Batran, Rami; Aburasayn, Hanin; Eshreif, Amina; Ho, Kim L; Ma, Wayne K; Almutairi, Malak; Eaton, Farah; Gandhi, Manoj; Park, Edwards A; Sutendra, Gopinath; Ussher, John R

    2017-09-01

    Pyruvate dehydrogenase (PDH) is the rate-limiting enzyme for glucose oxidation and a critical regulator of metabolic flexibility during the fasting to feeding transition. PDH is regulated via both PDH kinases (PDHK) and PDH phosphatases, which phosphorylate/inactivate and dephosphorylate/activate PDH, respectively. Our goal was to determine whether the transcription factor forkhead box O1 (FoxO1) regulates PDH activity and glucose oxidation in the heart via increasing the expression of Pdk4 , the gene encoding PDHK4. To address this question, we differentiated H9c2 myoblasts into cardiac myocytes and modulated FoxO1 activity, after which Pdk4 /PDHK4 expression and PDH phosphorylation/activity were assessed. We assessed binding of FoxO1 to the Pdk4 promoter in cardiac myocytes in conjunction with measuring the role of FoxO1 on glucose oxidation in the isolated working heart. Both pharmacological (1 µM AS1842856) and genetic (siRNA mediated) inhibition of FoxO1 decreased Pdk4 /PDHK4 expression and subsequent PDH phosphorylation in H9c2 cardiac myocytes, whereas 10 µM dexamethasone-induced Pdk4 /PDHK4 expression was abolished via pretreatment with 1 µM AS1842856. Furthermore, transfection of H9c2 cardiac myocytes with a vector expressing FoxO1 increased luciferase activity driven by a Pdk4 promoter construct containing the FoxO1 DNA-binding element region, but not in a Pdk4 promoter construct lacking this region. Finally, AS1842856 treatment in fasted mice enhanced glucose oxidation rates during aerobic isolated working heart perfusions. Taken together, FoxO1 directly regulates Pdk4 transcription in the heart, thereby controlling PDH activity and subsequent glucose oxidation rates. NEW & NOTEWORTHY Although studies have shown an association between FoxO1 activity and pyruvate dehydrogenase kinase 4 expression, our study demonstrated that pyruvate dehydrogenase kinase 4 is a direct transcriptional target of FoxO1 (but not FoxO3/FoxO4) in the heart. Furthermore, we

  1. blood pressure reducing effect of bitter kola in wistar rats

    African Journals Online (AJOL)

    DEAN'S OFFICE

    ABSTRACT: In this study the effect of Garcinia kola (GK) on blood pressure was investigated. Albino wistar rats were divided into three groups. Groups A rats had normal rat chow and water ad-libitum while groups B and C rats had Garcinia kola diet of 10% w/w and 15% w/w respectively, their blood pressures were ...

  2. Liver function of Streptozotocin- Induced Diabetic Rats Orally ...

    African Journals Online (AJOL)

    This study evaluated the liver status of STZ- induced diabetic rats treated with aqueous root-bark extract of T. tetraptera for 35 days. Twenty-four (24) rats in four groups (normal control, diabetic control, T. tetraptera treated STZ induced diabetic rats at 150 mg/kg b. w. and T. tetraptera treated STZ-diabetic rats at 300 mg/kg ...

  3. Comparative bone marrow responses of albino rats experimentally ...

    African Journals Online (AJOL)

    It involved laboratory based experimental infection of albino rats as research models. A total of 32 adult albino rats of mixed sexes were used for this investigation. The rats were randomly grouped into three groups, A, B, C made up of 8 rats each, and infected with T. congolense, T brucei and mixed infection of these species ...

  4. Social exclusion intensifies anxiety-like behavior in adolescent rats.

    Science.gov (United States)

    Lee, Hyunchan; Noh, Jihyun

    2015-05-01

    Social connection reduces the physiological reactivity to stressors, while social exclusion causes emotional distress. Stressful experiences in rats result in the facilitation of aversive memory and induction of anxiety. To determine the effect of social interaction, such as social connection, social exclusion and equality or inequality, on emotional change in adolescent distressed rats, the emotional alteration induced by restraint stress in individual rats following exposure to various social interaction circumstances was examined. Rats were assigned to one of the following groups: all freely moving rats, all rats restrained, rats restrained in the presence of freely moving rats and freely moving rats with a restrained rat. No significant difference in fear-memory and sucrose consumption between all groups was found. Change in body weight significantly increased in freely moving rats with a restrained rat, suggesting that those rats seems to share the stressful experience of the restrained rat. Interestingly, examination of the anxiety-like behavior revealed only rats restrained in the presence of freely moving rats to have a significant increase, suggesting that emotional distress intensifies in positions of social exclusion. These results demonstrate that unequally excluded social interaction circumstances could cause the amplification of distressed status and anxiety-related emotional alteration. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Correlation of histological and histometric changes in rats testes ...

    African Journals Online (AJOL)

    Histological and histometric changes in the testes of albino Wistar rats were correlated. Wistar rats weighing between 180-240g were randomly divided into three groups of ten rats each. One group served as control and the rats were given normal saline. The second and third groups received 2mg/kg and 4mg/kg body ...

  6. Anxiolytic Treatment Impairs Helping Behavior in Rats.

    Science.gov (United States)

    Ben-Ami Bartal, Inbal; Shan, Haozhe; Molasky, Nora M R; Murray, Teresa M; Williams, Jasper Z; Decety, Jean; Mason, Peggy

    2016-01-01

    Despite decades of research with humans, the biological mechanisms that motivate an individual to help others remain poorly understood. In order to investigate the roots of pro-sociality in mammals, we established the helping behavior test, a paradigm in which rats are faced with a conspecific trapped in a restrainer that can only be opened from the outside. Over the course of repeated test sessions, rats exposed to a trapped cagemate learn to open the door to the restrainer, thereby helping the trapped rat to escape (Ben-Ami Bartal et al., 2011). The discovery of this natural behavior provides a unique opportunity to probe the motivation of rodent helping behavior, leading to a deeper understanding of biological influences on human pro-sociality. To determine if an affective response motivates door-opening, rats receiving midazolam, a benzodiazepine anxiolytic, were tested in the helping behavior test. Midazolam-treated rats showed less helping behavior than saline-treated rats or rats receiving no injection. Yet, midazolam-treated rats opened a restrainer containing chocolate, highlighting the socially specific effects of the anxiolytic. To determine if midazolam interferes with helping through a sympatholytic effect, the peripherally restricted beta-adrenergic receptor antagonist nadolol was administered; nadolol did not interfere with helping. The corticosterone response of rats exposed to a trapped cagemate was measured and compared to the rats' subsequent helping behavior. Rats with the greatest corticosterone responses showed the least helping behavior and those with the smallest responses showed the most consistent helping at the shortest latency. These results are discussed in terms of their implications for the interaction between stress and pro-social behavior. Finally, we observed that door-opening appeared to be reinforcing. A novel analytical tool was designed to interrogate the pattern of door-opening for signs that a rat's behavior on one session

  7. Generation and characterization of rat liver stem cell lines and their engraftment in a rat model of liver failure

    NARCIS (Netherlands)

    Kuijk, Ewart W; Rasmussen, Shauna; Blokzijl, Francis; Huch, Meritxell; Gehart, Helmuth; Toonen, Pim; Begthel, Harry; Clevers, Hans; Geurts, Aron M; Cuppen, Edwin

    2016-01-01

    The rat is an important model for liver regeneration. However, there is no in vitro culture system that can capture the massive proliferation that can be observed after partial hepatectomy in rats. We here describe the generation of rat liver stem cell lines. Rat liver stem cells, which grow as

  8. Lessons From Experiments in Rats

    Directory of Open Access Journals (Sweden)

    Albert Gramsbergen

    2001-01-01

    Full Text Available In this essay a few relevant aspects of the neural and behavioral development of the brain in the human and in the rat are reviewed and related to the consequences of lesions in the central and peripheral nervous system at early and later age. Movements initially are generated by local circuits in the spinal cord and without the involvement of descending projections. After birth, both in humans and in rats it seems that the devlopment of postural control is the limiting factor for several motor behaviors to mature. Strong indications exist that the cerebellum is significantly involved in this control. Lesions in the CNS at early stages interfere with fundamental processes of neural development, such as the establishment of fiber connections and cell death patterns. Consequently, the functional effects are strongly dependent on the stage of development. The young and undisturbed CNS, on the other hand, has a much greater capacity than the adult nervous system for compensating abnormal reinnervation in the peripheral nervous system. Animal experiments indicated that the cerebellar cortex might play an important part in this compensation. This possibility should be investigated further as it might offer important perspectives for treatment in the human.

  9. Analysis of vkorc1 polymorphisms in Norway rats using the roof rat as outgroup.

    Science.gov (United States)

    Díaz, Juan C; Song, Ying; Moore, Anthony; Borchert, Jeff N; Kohn, Michael H

    2010-05-24

    Certain mutations in the vitamin K epoxide reductase subcomponent 1 gene (vkorc1) mediate rodent resistance to warfarin and other anticoagulants. Testing for resistance often involves analysis of the vkorc1. However, a genetic test for the roof rat (Rattus rattus) has yet to be developed. Moreover, an available roof rat vkorc1 sequence would enable species identification based on vkorc1 sequence and the evaluation of natural selection on particular vkorc1 polymorphisms in the Norway rat (R. norvegicus). We report the coding sequence, introns and 5' and 3' termini for the vkorc1 gene of roof rats (R. r. alexandrinus and R. r. frugivorus) from Uganda, Africa. Newly designed PCR primers now enable genetic testing of the roof rat and Norway rat. Only synonymous and noncoding polymorphisms were found in roof rats from Uganda. Both nominal subspecies of roof rats were indistinguishable from each other but were distinct from R. losea and R. flavipectus; however, the roof rat also shares at least three coding sequence polymorphisms with R. losea and R. flavipectus. Many of recently published vkorc1 synonymous and non-synonymous single nucleotide polymorphisms (SNPs) in Norway rats are likely SNPs from roof rats and/or other Rattus species. Tests applied to presumably genuine Norway rat vkorc1 SNPs are consistent with a role for selection in two populations carrying the derived Phe63Cys and Tyr139Cys mutations. Geographic mapping of vkorc1 SNPs in roof rats should be facilitated by our report. Our assay should be applicable to most species of Rattus, which are intermediate in genetic distance from roof and Norway rats. Vkorc1-mediated resistance due to non-synonymous coding SNPs is not segregating in roof rats from Uganda. By using the roof rat sequence as a reference vkorc1, SNPs now can be assigned to the correct rat species with more confidence. Sampling designs and genotyping strategies employed so far have helped detect candidate mutations underlying vkorc1-mediated

  10. Decline of umami preference in aged rats.

    Science.gov (United States)

    Miura, Hirohito; Ooki, Makoto; Kanemaru, Norikazu; Harada, Shuitsu

    2014-08-08

    The effects of aging on the umami sensation were compared between the preference and neural responses from the greater superficial petrosal nerve (GSP innervating the soft palate) and the chorda tympani nerve (CT innervating the fungiform papillae) in the Sprague Dawley rat. A two-bottle preference test revealed that younger rats (5-12 weeks) preferred significantly 0.001 M 5'-inosine monophosphate (IMP), 0.01 M mono sodium glutamate (MSG), and binary mixtures of 0.001 M IMP+0.01 M MSG than deionized water. However, aged rats (21-22 months) showed no significant preference to these umami solutions compared to deionized water. Among the other four basic taste stimuli, there were no significant differences in preference between young and aged rats. Regardless of the age of the rat, neural responses from the GSP and CT produced robust integrated responses to all three umami solutions used in the two-bottle tests. These results indicate that the lack of preference to umami in aged rats is a central nervous system phenomenon and suggests that the loss of preference to umami taste in aged rats is caused by homeostatic changes in the brain incurred by aging. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Fetal rat pancreas transplantation in BB rats: immunohistochemical and functional evaluation

    DEFF Research Database (Denmark)

    Yderstræde, Knud Bonnet; Starklint, Henrik; Steinbrüchel, Daniel Andreas

    1993-01-01

    Spontaneously diabetic BB/Wor rats received either a syngeneic fetal pancreas transplant or adult islets. In the former, 4-8 fetal pancreases were transplanted, and in the latter, 3-5000 islets. Transplantation was performed by transferring a blood clot containing the pancreases or islets...... to the renal subcapsular space. Insulin therapy was undertaken postoperatively, except in one experiment with adult islets. Of the fetal pancreas transplanted BB rats, 52% became normoglycaemic, and 21% remained so throughout an observation period of 10 months. Nephrectomy caused a prompt return of diabetes....... The histological appearance of the grafts transplanted to the diabetic animals closely resembled that of grafts transplanted to normal rats in a parallel series. For comparison a group of BB rats received a syngeneic transplant of isolated adult islets from WF rats or BBW rats. Following adult islet...

  12. Detection of rat hepatitis E virus in wild Norway rats (Rattus norvegicus) and Black rats (Rattus rattus) from 11 European countries.

    Science.gov (United States)

    Ryll, René; Bernstein, Samuel; Heuser, Elisa; Schlegel, Mathias; Dremsek, Paul; Zumpe, Maxi; Wolf, Sandro; Pépin, Michel; Bajomi, Daniel; Müller, Gabi; Heiberg, Ann-Charlotte; Spahr, Carina; Lang, Johannes; Groschup, Martin H; Ansorge, Hermann; Freise, Jona; Guenther, Sebastian; Baert, Kristof; Ruiz-Fons, Francisco; Pikula, Jiri; Knap, Nataša; Tsakmakidis, Ιoannis; Dovas, Chrysostomos; Zanet, Stefania; Imholt, Christian; Heckel, Gerald; Johne, Reimar; Ulrich, Rainer G

    2017-09-01

    Rat hepatitis E virus (HEV) is genetically only distantly related to hepeviruses found in other mammalian reservoirs and in humans. It was initially detected in Norway rats (Rattus norvegicus) from Germany, and subsequently in rats from Vietnam, the USA, Indonesia, China, Denmark and France. Here, we report on a molecular survey of Norway rats and Black rats (Rattus rattus) from 12 European countries for ratHEV and human pathogenic hepeviruses. RatHEV-specific real-time and conventional RT-PCR investigations revealed the presence of ratHEV in 63 of 508 (12.4%) rats at the majority of sites in 11 of 12 countries. In contrast, a real-time RT-PCR specific for human pathogenic HEV genotypes 1-4 and a nested broad-spectrum (NBS) RT-PCR with subsequent sequence determination did not detect any infections with these genotypes. Only in a single Norway rat from Belgium a rabbit HEV-like genotype 3 sequence was detected. Phylogenetic analysis indicated a clustering of all other novel Norway and Black rat-derived sequences with ratHEV sequences from Europe, the USA and a Black rat-derived sequence from Indonesia within the proposed ratHEV genotype 1. No difference in infection status was detected related to age, sex, rat species or density of human settlements and zoological gardens. In conclusion, our investigation shows a broad geographical distribution of ratHEV in Norway and Black rats from Europe and its presence in all settlement types investigated. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Electrocardiography in rats: a comparison to human.

    Science.gov (United States)

    Konopelski, P; Ufnal, M

    2016-11-23

    Electrocardiography (ECG) in rats is a widely applied experimental method in basic cardiovascular research. The technique of ECG recordings is simple; however, the interpretation of electrocardiographic parameters is challenging. This is because the analysis may be biased by experimental settings, such as the type of anesthesia, the strain or age of animals. Here, we aimed to review electrocardiographic parameters in rats, their normal range, as well as the effect of experimental settings on the parameters variation. Furthermore, differences and similarities between rat and human ECG are discussed in the context of translational cardiovascular research.

  14. Oral Gavage in Rats: Animal Welfare Evaluation

    OpenAIRE

    Turner, Patricia V.; Vaughn, Elizabeth; Sunohara-Neilson, Janet; Ovari, Jelena; Leri, Francesco

    2012-01-01

    The effect of chronic daily orogastric gavage with water (5 mL/kg) on behavior and physiology was evaluated in male Sprague–Dawley rats. Treatment groups included: unmanipulated control, restraint control, dry gavage, and gavage, with all rats singly housed (n = 9 or 10 per group). In addition, a group of pair-housed rats (n = 18) was included to determine whether social housing affected response to gavage. Weekly body weights and food consumption were recorded as well as use of a nylon chew ...

  15. Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats

    Science.gov (United States)

    TANAKA, Masami; WATANABE, Minoru; YOKOMI, Izuru; MATSUMOTO, Naoki; SUDO, Katsuko; SATOH, Hitoshi; IGARASHI, Tsuneo; SEKI, Azusa; AMANO, Hitoshi; OHURA, Kiyoshi; RYU, Kakei; SHIBATA, Shunichi; NAGAYAMA, Motohiko; TANUMA, Jun-ichi

    2014-01-01

    Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats. PMID:25736479

  16. How rats combine temporal cues.

    Science.gov (United States)

    Guilhardi, Paulo; Keen, Richard; MacInnis, Mika L M; Church, Russell M

    2005-05-31

    The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

  17. Tissue disposition of bifenthrin in the rat

    Data.gov (United States)

    U.S. Environmental Protection Agency — Tissue disposition of bifenthrin in the rat and oral and intravenous administration. This dataset is associated with the following publication: Hughes , M., D. Ross...

  18. Black ginseng extract ameliorates hypercholesterolemia in rats

    Directory of Open Access Journals (Sweden)

    Evelyn Saba

    2016-04-01

    Conclusion: Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

  19. Thermal biology of the laboratory rat.

    Science.gov (United States)

    Gordon, C J

    1990-05-01

    The purpose of this paper is to thoroughly review the literature and present a data base of the basic thermoregulatory parameters of the laboratory rat. This review surveys the pertinent papers dealing with various aspects of the thermal biology of the laboratory rat, including: metabolism, thermoneutrality, core and brain temperature, thermal tolerance, thermal conductance and insulation, thermoregulatory effectors (i.e., thermogenesis, peripheral vasomotor tone, evaporation, and behavior), thermal acclimation, growth and reproduction, ontogeny, aging, motor activity and exercise, circadian rhythm and sleep, gender differences, and other parameters. It is shown that many facets of the thermoregulatory system of the laboratory rat are typical to that of most homeothermic species. However, is several instances the rat exhibits unique thermoregulatory responses which are not comparable to other species.

  20. Comeback of the Rat in Biomedical Research

    NARCIS (Netherlands)

    Homberg, J.R.; Wohr, M.; Alenina, N.

    2017-01-01

    Rats were the first mammalian species domesticated for scientific purposes, and they soon became the most widely used animal model in biomedical sciences, including cardiovascular research and behavioral neuroscience. Yet, after the development of technologies to manipulate genes, researchers

  1. Experimental model to induce obesity in rats

    National Research Council Canada - National Science Library

    Vinicius Von Diemen; Eduardo Neubarth Trindade; Manoel Roberto Maciel Trindade

    2006-01-01

    .... Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH...

  2. Reduced graphene oxide: nanotoxicological profile in rats

    National Research Council Canada - National Science Library

    Mendonça, Monique Culturato Padilha; Soares, Edilene Siqueira; de Jesus, Marcelo Bispo; Ceragioli, Helder José; Irazusta, Silvia Pierre; Batista, Ângela Giovana; Vinolo, Marco Aurélio Ramirez; Maróstica Júnior, Mário Roberto; da Cruz-Höfling, Maria Alice

    2016-01-01

    We have previously demonstrated that reduced graphene oxide (rGO) administered intravenously in rats was detected inside the hippocampus after downregulation of the tight and adherens junction proteins of the blood-brain barrier...

  3. Rat Bite Fever Resembling Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Ripa Akter

    2016-01-01

    Full Text Available Rat bite fever is rare in Western countries. It can be very difficult to diagnose as blood cultures are typically negative and a history of rodent exposure is often missed. Unless a high index of suspicion is maintained, the associated polyarthritis can be mistaken for rheumatoid arthritis. We report a case of culture-positive rat bite fever in a 46-year-old female presenting with fever and polyarthritis. The clinical presentation mimicked rheumatoid arthritis. Infection was complicated by discitis, a rare manifestation. We discuss the diagnosis and management of this rare zoonotic infection. We also review nine reported cases of rat bite fever, all of which had an initial presumptive diagnosis of a rheumatological disorder. Rat bite fever is a potentially curable infection but can have a lethal course if left untreated.

  4. Rat sperm motility analysis: methodologic considerations

    Science.gov (United States)

    The objective of these studies was to optimize conditions for computer-assisted sperm analysis (CASA) of rat epididymal spermatozoa. Methodologic issues addressed include sample collection technique, sampling region within the epididymis, type of diluent medium used, and sample c...

  5. Penile autotransplantation in rats: An animal model

    Directory of Open Access Journals (Sweden)

    Raouf M Seyam

    2013-01-01

    Conclusions: Penile autotransplantation in rats is feasible and provides the basis for evaluation of the corpora cavernosa in an allotransplantation model. Long-term urethral continuity and dorsal neurovascular bundle survival in this model is difficult to establish.

  6. Reactive Protein Synthesis in Pregnant Rats

    African Journals Online (AJOL)

    olayemitoyin

    /kg) groups. At terminal gestation day (GD) ranging from 0-20, the rats were sacrificed, and blood samples and amniotic fluids were collected. Thyroid hormone, C-reactive protein (CRP) and leptin assay was carried using the blood samples.

  7. A Focused Microarray for Screening Rat Embryonic Stem Cell Lines

    Science.gov (United States)

    Hong, James; He, Hong; Bui, Phuoc; Ryba-White, Ben; Rumi, Mohammad A.K.; Soares, Michael J.; Dutta, Debasree; Paul, Soumen; Kawamata, Masaki; Ochiya, Takahiro; Ying, Qi-Long; Rajanahalli, Pavan

    2013-01-01

    Here, we describe a focused microarray for screening rat embryonic stem cells (ESCs) and provide validation data that this array can distinguish undifferentiated rat ESCs from rat trophoblast stem (TS) cells, rat extraembryonic endoderm cells, mouse embryonic fibroblast feeder cells, and differentiated rat ESCs. Using this tool, genuine rat ESC lines, which have been expanded in a conventional rat ESC medium containing two inhibitors (2i), for example, glycogen synthase kinase 3 (GSK3) and mitogen-activated protein kinase (MEK) inhibitors, and leukemia inhibitory factor, and genuine rat ESCs, which have been expanded in rat ESC medium containing four inhibitors (4i), for example, GSK3, MEK, Alk5, and Rho-associated kinase inhibitors were compared; as were genuine rat ESCs from 4 different strains of rats. Expression of Cdx2, a gene associated with trophoblast determination, was observed in genuine, undifferentiated rat ESCs from 4 strains and from both 2i and 4i ESC derivation medium. This finding is in contrast to undifferentiated mouse ESCs that do not express Cdx2. The rat ESC focused microarray described in this report has utility for rapid screening of rat ESCs. This tool will enable optimization of culture conditions in the future. PMID:22889370