scholarly journals Myostatin-1 Inhibits Cell Proliferation by Inhibiting the mTOR Signal Pathway and MRFs, and Activating the Ubiquitin-Proteasomal System in Skeletal Muscle Cells of Japanese Flounder Paralichthys olivaceus

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2376
Author(s):  
Jiahuan Liu ◽  
Mingzhu Pan ◽  
Dong Huang ◽  
Yanlin Guo ◽  
Mengxi Yang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Mrna Expression ◽  
Biological Effects ◽  
Paralichthys Olivaceus ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Signal Pathway ◽  
Japanese Flounder ◽  
Negative Regulator

Myostatin (MSTN) is a negative regulator of skeletal muscle growth and development. The mechanisms of fish MSTN involved in muscle growth are not fully understood. In the present study, knockdown and overexpression of mstn-1 was performed in cultured Japanese flounder muscle cells to investigate the molecular function and the underlying mechanism of fish MSTN-1. Results showed that mstn-1 knockdown significantly induced cell proliferation and the mRNA expression of myogenic regulatory factors (MRFs), while overexpression of mstn-1 led to a significant decrease of cell proliferation and a suppression of the MRFs mRNA expression. The overexpression of mstn-1 also significantly increased the mRNA expression of ubiquitin–proteasomal pathway of proteolysis genes including muscle RING-finger protein 1 (murf-1) by 204.1% (p = 0.024) and muscle atrophy F-box protein (mafbx) by 165.7% (p = 0.011). However, mystn-1 overexpression inhibited the activation of mTOR signal pathway and the AKT/FoxO1 pathway through decreasing phosphorylation of AKT at Ser 473 by 56.0% (p = 0.001). Meanwhile, mystn-1 overexpression increased the dephosphorylation and nuclear localization of FoxO1 by 394.9% (p = 0.005). These results demonstrate that mstn-1 in Japanese flounder has the effects of inhibiting cell proliferation and growth, and the mTOR and AKT/FoxO1 pathways participated in these biological effects.

Myostatin inhibits proliferation and insulin-stimulated glucose uptake in mouse liver cells

2014 ◽  
Vol 92 (3) ◽  
pp. 226-234 ◽  
Author(s):  
Rani Watts ◽  
Mostafa Ghozlan ◽  
Curtis C. Hughey ◽  
Virginia L. Johnsen ◽  
Jane Shearer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Glucose Uptake ◽  
Liver Cell ◽  
Noncoding Rna ◽  
Muscle Growth ◽  
Liver Cells ◽  
Negative Regulator ◽  
Kinase Substrate ◽  
Akt Phosphorylation

Although myostatin functions primarily as a negative regulator of skeletal muscle growth and development, accumulating biological and epidemiological evidence indicates an important contributing role in liver disease. In this study, we demonstrate that myostatin suppresses the proliferation of mouse Hepa-1c1c7 murine-derived liver cells (50%; p < 0.001) in part by reducing the expression of the cyclins and cyclin-dependent kinases that elicit G1-S phase transition of the cell cycle (p < 0.001). Furthermore, real-time PCR-based quantification of the long noncoding RNA metastasis associated lung adenocarcinoma transcript 1 (Malat1), recently identified as a myostatin-responsive transcript in skeletal muscle, revealed a significant downregulation (25% and 50%, respectively; p < 0.05) in the livers of myostatin-treated mice and liver cells. The importance of Malat1 in liver cell proliferation was confirmed via arrested liver cell proliferation (p < 0.05) in response to partial Malat1 siRNA-mediated knockdown. Myostatin also significantly blunted insulin-stimulated glucose uptake and Akt phosphorylation in liver cells while increasing the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS), a protein that is essential for cancer cell proliferation and insulin-stimulated glucose transport. Together, these findings reveal a plausible mechanism by which circulating myostatin contributes to the diminished regenerative capacity of the liver and diseases characterized by liver insulin resistance.

scholarly journals The Possible Role of Complete Loss of Myostatin in Limiting Excessive Proliferation of Muscle Cells (C2C12) via Activation of MicroRNAs

2019 ◽  
Vol 20 (3) ◽  
pp. 643 ◽  
Author(s):  
Peixuan Huang ◽  
Daxin Pang ◽  
Kankan Wang ◽  
Aishi Xu ◽  
Chaogang Yao ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Muscle Growth ◽  
Interaction Network ◽  
Muscle Cells ◽  
Complete Loss ◽  
Skeletal Muscle Growth ◽  
Excessive Proliferation ◽  
Mouse Myoblast

Myostatin (MSTN) is a member of the TGF-β superfamily that negatively regulates skeletal muscle growth and differentiation. However, the mechanism by which complete MSTN deletion limits excessive proliferation of muscle cells remains unclear. In this study, we knocked out MSTN in mouse myoblast lines using a Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9) system and sequenced the mRNA and miRNA transcriptomes. The results show that complete loss of MSTN upregulates seven miRNAs targeting an interaction network composed of 28 downregulated genes, including TGFB1, FOS and RB1. These genes are closely associated with tumorigenesis and cell proliferation. Our study suggests that complete loss of MSTN may limit excessive cell proliferation via activation of miRNAs. These data will contribute to the treatment of rhabdomyosarcoma (RMS).

Myostatin inhibits cell proliferation and protein synthesis in C2C12 muscle cells

2001 ◽  
Vol 280 (2) ◽  
pp. E221-E228 ◽  
Author(s):  
Wayne E. Taylor ◽  
Shalender Bhasin ◽  
Jorge Artaza ◽  
Frances Byhower ◽  
Mohd Azam ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Dna Synthesis ◽  
Muscle Mass ◽  
Chinese Hamster Ovary Cells ◽  
Muscle Cells ◽  
Negative Regulator ◽  
Free System

Myostatin mutations in mice and cattle are associated with increased muscularity, suggesting that myostatin is a negative regulator of skeletal muscle mass. To test the hypothesis that myostatin inhibits muscle cell growth, we examined the effects of recombinant myostatin in mouse skeletal muscle C2C12 cells. After verification of the expression of cDNA constructs in a cell-free system and in transfected Chinese hamster ovary cells, the human recombinant protein was expressed as the full-length (375-amino acid) myostatin in Drosophila cells (Mst375D), or the 110-amino acid carboxy-terminal protein in Escherichia coli(Mst110EC). These proteins were identified by immunoblotting and were purified. Both Mst375D and Mst110EC dose dependently inhibited cell proliferation (cell count and Formazan assay), DNA synthesis ([3H]thymidine incorporation), and protein synthesis ([1-14C]leucine incorporation) in C2C12 cells. The inhibitory effects of both proteins were greater in myotubes than in myoblasts. Neither protein had any significant effects on protein degradation or apoptosis. In conclusion, recombinant myostatin proteins inhibit cell proliferation, DNA synthesis, and protein synthesis in C2C12muscle cells, suggesting that myostatin may control muscle mass by inhibiting muscle growth or regeneration.

scholarly journals MicroRNA-33a negatively regulates myoblast proliferation by targeting IGF1, follistatin and cyclin D1

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Xinxin Li ◽  
Jiamin Qiu ◽  
Hehe Liu ◽  
Yan Deng ◽  
Shenqiang Hu ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Growth Factor ◽  
Cyclin D1 ◽  
Mrna Expression ◽  
Cancer Cells ◽  
Negative Regulator ◽  
Mtor Signaling Pathway ◽  
Down Regulation ◽  
Myoblast Proliferation

Abstract MiR-33a is found as a regulator of cell proliferation in many cancer cells. However, it remains unknown if and how miR-33a plays a role in myoblast proliferation. To investigate the effect of miR-33a on myoblast proliferation, miR-33a mimic or inhibitor was co-administered with or without insulin-like growth factor 1 (IGF1) to simulation myoblasts. Our study showed that up-regulation of miR-33a impaired myoblast proliferation, while down-regulation of miR-33a enhanced myoblast proliferation. Mechanistically, we examined that miR-33a can inhibit the transcription of IGF1, follistatin (FST) and cyclin D1 (CCND1) by targeting their 3′UTR region in both HEK293T cells and duck myoblasts. Moreover, up-regulation of miR-33a decreased and its down-regulation increased the mRNA expression of PI3K, Akt, mTOR and S6K. Importantly, the decreased PI3K, Akt, mTOR and S6K expression by miR-33a mimics was abrogated by co-administered with IGF1. Altogether, our results demonstrated that miR-33a may directly target IGF1, FST and CCND1 to inhibit myoblast proliferation via PI3K/Akt/mTOR signaling pathway. In conclusion, miR-33a is a potential negative regulator of myoblast proliferation and by modulating its expression could promote the early development of skeletal muscle.

scholarly journals Ascorbic Acid Supplementation Improves Skeletal Muscle Growth in Pacu (Piaractus mesopotamicus) Juveniles: In Vivo and In Vitro Studies

2021 ◽  
Vol 22 (6) ◽  
pp. 2995
Author(s):  
Bruna Tereza Thomazini Zanella ◽  
Isabele Cristina Magiore ◽  
Bruno Oliveira Silva Duran ◽  
Guilherme Gutierrez Pereira ◽  
Igor Simões Tiagua Vicente ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Ascorbic Acid ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Cell Diameter ◽  
Piaractus Mesopotamicus ◽  
Expression Of Genes

In fish, fasting leads to loss of muscle mass. This condition triggers oxidative stress, and therefore, antioxidants can be an alternative to muscle recovery. We investigated the effects of antioxidant ascorbic acid (AA) on the morphology, antioxidant enzyme activity, and gene expression in the skeletal muscle of pacu (Piaractus mesopotamicus) following fasting, using in vitro and in vivo strategies. Isolated muscle cells of the pacu were subjected to 72 h of nutrient restriction, followed by 24 h of incubation with nutrients or nutrients and AA (200 µM). Fish were fasted for 15 days, followed by 6 h and 15 and 30 days of refeeding with 100, 200, and 400 mg/kg of AA supplementation. AA addition increased cell diameter and the expression of anabolic and cell proliferation genes in vitro. In vivo, 400 mg/kg of AA increased anabolic and proliferative genes expression at 6 h of refeeding, the fiber diameter and the expression of genes related to cell proliferation at 15 days, and the expression of catabolic and oxidative metabolism genes at 30 days. Catalase activity remained low in the higher supplementation group. In conclusion, AA directly affected the isolated muscle cells, and the higher AA supplementation positively influenced muscle growth after fasting.

Anemic Hypoxemia Reduces Myoblast Proliferation and Muscle Growth in Late Gestation Fetal Sheep

2021 ◽  
Author(s):  
Paul J. Rozance ◽  
Stephanie R Wesolowski ◽  
Sonnet S. Jonker ◽  
Laura D Brown
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Muscle Growth ◽  
Late Gestation ◽  
Whole Body ◽  
Myoblast Differentiation ◽  
Fetal Sheep ◽  
Body Protein ◽  
Skeletal Muscle Growth ◽  
Myoblast Proliferation

Fetal skeletal muscle growth requires myoblast proliferation, differentiation, and fusion into myofibers in addition to protein accretion for fiber hypertrophy. Oxygen is an important regulator of this process. Therefore, we hypothesized that fetal anemic hypoxemia would inhibit skeletal muscle growth. Studies were performed in late gestation fetal sheep that were bled to anemic, and therefore hypoxemic, conditions beginning at ~125 days of gestation (term = 148 days) for 9 ± 0 days (n=19) and compared to control fetuses (n=16). A metabolic study was performed on gestational day ~134 to measure fetal protein kinetic rates. Myoblast proliferation and myofiber area were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. mRNA expression of muscle regulatory factors was determined in BF. Fetal arterial hematocrit and oxygen content were 28% and 52% lower, respectively, in anemic fetuses. Fetal weight and whole-body protein synthesis, breakdown, and accretion rates were not different between groups. Hindlimb length, however, was 7% shorter in anemic fetuses. TA and FDS muscles weighed less and FDS myofiber area was smaller in anemic fetuses compared to controls. The percentage of Pax7+ myoblasts that expressed Ki67 was lower in BF and tended to be lower in FDS from anemic fetuses indicating reduced myoblast proliferation. There was less MYOD and MYF6 mRNA expression in anemic vs. control BF consistent with reduced myoblast differentiation. These results indicate that fetal anemic hypoxemia reduced muscle growth. We speculate that fetal muscle growth may be improved by strategies that increase oxygen availability.

Transcriptomic Analysis of MSTN Knockout in the Early Differentiation of Chicken Fetal Myoblasts

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Ke Xu ◽  
Hao Zhou ◽  
Chengxiao Han ◽  
Zhong Xu ◽  
Jinmei Ding ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Molecular Mechanism ◽  
Growth And Development ◽  
Biological Effects ◽  
Muscle Growth ◽  
Negative Regulator ◽  
Myoblast Differentiation ◽  
Fatty Acid Binding ◽  
Knock Out ◽  
Early Differentiation

In mammals, Myostatin (MSTN) is a known negative regulator of muscle growth and development, but its role in birds is poorly understood. To investigate the molecular mechanism of MSTN on muscle growth and development in chickens, we knocked out MSTN in chicken fetal myoblasts (CFMs) and sequenced the mRNA transcriptomes. The amplicon sequencing results show that the editing efficiency of the cells was 76%. The transcriptomic results showed that 296 differentially expressed genes were generated after down-regulation of MSTN, including angiotensin I converting enzyme (ACE), extracellular fatty acid-binding protein (EXFABP) and troponin T1, slow skeletal type (TNNT1). These genes are closely associated with myoblast differentiation, muscle growth and energy metabolism. Subsequent enrichment analysis showed that DEGs of CFMs were related to MAPK, P13K/AKT, and STAT3 signaling pathways. The MAPK and P13K/AKT signaling pathways are two of the three known signaling pathways involved in the biological effects of MSTN in mammals, and the STAT3 pathway is also significantly enriched in MSTN knock out chicken leg muscles. The results of this study will help to understand the possible molecular mechanism of MSTN regulating the early differentiation of CFMs and lay a foundation for further research on the molecular mechanism of MSTN involvement in muscle growth and development.

IL-4 and IL-13 upregulate arginase I expression by cAMP and JAK/STAT6 pathways in vascular smooth muscle cells

2000 ◽  
Vol 279 (1) ◽  
pp. C248-C256 ◽  
Author(s):  
Liu Hua Wei ◽  
Aaron T. Jacobs ◽  
Sidney M. Morris ◽  
Louis J. Ignarro
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Protein Levels ◽  
Ifn Γ ◽  
Arginase Ii ◽  
Arginase I

The objectives of this study were to determine whether rat aortic smooth muscle cells (RASMC) express arginase and to elucidate the possible mechanisms involved in the regulation of arginase expression. The results show that RASMC contain basal arginase I (AI) activity, which is significantly enhanced by stimulating the cells with either interleukin (IL)-4 or IL-13, but arginase II (AII) expression was not detected under any condition studied here. We further investigated the signal transduction pathways responsible for AI induction. AI mRNA and protein levels were enhanced by addition of forskolin (1 μM) and inhibited by H-89 (30 μM), suggesting positive regulation of AI by a protein kinase A pathway. Genistein (10 μg/ml) and sodium orthovanadate (Na3VO4; 10 μM) were used to investigate the role of tyrosine phosphorylation in the control of AI expression. Genistein inhibited, whereas Na3VO4enhanced the induction of AI by IL-4 or IL-13. Along with immunoprecipitation and immunoblot analyses, these data implicate the JAK/STAT6 pathway in AI regulation. Dexamethasone (Dex) and interferon (IFN)-γ were investigated for their effects on AI induction. Dex (1 μM) and IFN-γ (100 U/ml) alone had no effect on basal AI expression in RASMC, but both reduced AI induction by IL-4 and IL-13. In combination, Dex and IFN-γ abolished AI induction by IL-4 and IL-13. Finally, both IL-4 and IL-13 significantly increased RASMC DNA synthesis as monitored by [3H]thymidine incorporation, demonstrating that upregulation of AI is correlated with an increase in cell proliferation. Blockade of AI induction by IFN-γ, H-89, or genistein also blocked the increase in cell proliferation. These observations are consistent with the possibility that upregulation of AI might play an important role in the pathophysiology of vascular disorders characterized by excessive smooth muscle growth.

Interleukin-6 promotes myogenic differentiation of mouse skeletal muscle cells: role of the STAT3 pathway

2013 ◽  
Vol 304 (2) ◽  
pp. C128-C136 ◽  
Author(s):  
Miriam Hoene ◽  
Heike Runge ◽  
Hans Ulrich Häring ◽  
Erwin D. Schleicher ◽  
Cora Weigert
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Myogenic Differentiation ◽  
Muscle Cells ◽  
C2c12 Cells ◽  
Skeletal Muscle Cells ◽  
Wild Type ◽  
C2c12 Myoblasts ◽  
Sequence Of Events ◽  
Primary Mouse

Myogenic differentiation of skeletal muscle cells is characterized by a sequence of events that include activation of signal transducer and activator of transcription 3 (STAT3) and enhanced expression of its target gene Socs3. Autocrine effects of IL-6 may contribute to the activation of the STAT3-Socs3 cascade and thus to myogenic differentiation. The importance of IL-6 and STAT3 for the differentiation process was studied in C2C12 cells and in primary mouse wild-type and IL-6−/− skeletal muscle cells. In differentiating C2C12 myoblasts, the upregulation of IL-6 mRNA expression and protein secretion started after increased phosphorylation of STAT3 on tyrosine 705 and increased mRNA expression of Socs3 was observed. Knockdown of STAT3 and IL-6 mRNA in differentiating C2C12 myoblasts impaired the expression of the myogenic markers myogenin and MyHC IIb and subsequently myotube fusion. However, the knockdown of IL-6 did not prevent the induction of STAT3 tyrosine phosphorylation. The IL-6-independent activation of STAT3 was verified in differentiating primary IL-6−/− myoblasts. The phosphorylation of STAT3 and the expression levels of STAT3, Socs3, and myogenin during differentiation were comparable in the primary myoblasts independent of the genotype. However, IL-6−/− cells failed to induce MyHC IIb expression to the same level as in wild-type cells and showed reduced myotube formation. Supplementation of IL-6 could partially restore the fusion of IL-6−/− cells. These data demonstrate that IL-6 depletion during myogenic differentiation does not reduce the activation of the STAT3-Socs3 cascade, while IL-6 and STAT3 are both necessary to promote myotube fusion.

scholarly journals Effect of differentiation, de novo innervation, and electrical pulse stimulation on mRNA and protein expression of Na+,K+-ATPase, FXYD1, and FXYD5 in cultured human skeletal muscle cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247377
Author(s):  
Vid Jan ◽  
Katarina Miš ◽  
Natasa Nikolic ◽  
Klemen Dolinar ◽  
Metka Petrič ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mrna Expression ◽  
Human Skeletal Muscle ◽  
De Novo ◽  
Muscle Cells ◽  
Electrical Pulse ◽  
Electrical Pulse Stimulation ◽  
Human Skeletal Muscle Cells ◽  
Pulse Stimulation ◽  
Low Serum

Denervation reduces the abundance of Na+,K+-ATPase (NKA) in skeletal muscle, while reinnervation increases it. Primary human skeletal muscle cells, the most widely used model to study human skeletal muscle in vitro, are usually cultured as myoblasts or myotubes without neurons and typically do not contract spontaneously, which might affect their ability to express and regulate NKA. We determined how differentiation, de novo innervation, and electrical pulse stimulation affect expression of NKA (α and β) subunits and NKA regulators FXYD1 (phospholemman) and FXYD5 (dysadherin). Differentiation of myoblasts into myotubes under low serum conditions increased expression of myogenic markers CD56 (NCAM1), desmin, myosin heavy chains, dihydropyridine receptor subunit α1S, and SERCA2 as well as NKAα2 and FXYD1, while it decreased expression of FXYD5 mRNA. Myotubes, which were innervated de novo by motor neurons in co-culture with the embryonic rat spinal cord explants, started to contract spontaneously within 7–10 days. A short-term co-culture (10–11 days) promoted mRNA expression of myokines, such as IL-6, IL-7, IL-8, and IL-15, but did not affect mRNA expression of NKA, FXYDs, or myokines, such as musclin, cathepsin B, meteorin-like protein, or SPARC. A long-term co-culture (21 days) increased the protein abundance of NKAα1, NKAα2, FXYD1, and phospho-FXYD1Ser68 without attendant changes in mRNA levels. Suppression of neuromuscular transmission with α-bungarotoxin or tubocurarine for 24 h did not alter NKA or FXYD mRNA expression. Electrical pulse stimulation (48 h) of non-innervated myotubes promoted mRNA expression of NKAβ2, NKAβ3, FXYD1, and FXYD5. In conclusion, low serum concentration promotes NKAα2 and FXYD1 expression, while de novo innervation is not essential for upregulation of NKAα2 and FXYD1 mRNA in cultured myotubes. Finally, although innervation and EPS both stimulate contractions of myotubes, they exert distinct effects on the expression of NKA and FXYDs.

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