Molecular expression of myostatin and MyoD is greater in double-muscled than normal-muscled cattle fetuses

2001 ◽  
Vol 280 (5) ◽  
pp. R1488-R1493 ◽  
Author(s):  
J. M. Oldham ◽  
J. A. K. Martyn ◽  
M. Sharma ◽  
F. Jeanplong ◽  
R. Kambadur ◽  
...  

Excessive muscling in double-muscled cattle arises from mutations in the myostatin gene, but the role of myostatin in normal muscle development is unclear. The aim of this study was to measure the temporal relationship of myostatin and myogenic regulatory factors during muscle development in normal (NM)- and double-muscled (DM) cattle to determine the timing and possible targets of myostatin action in vivo. Myostatin mRNA peaked at the onset of secondary fiber formation ( P < 0.001) and was greater in DM ( P < 0.001) than in NM. MyoD expression was also elevated throughout primary and secondary fiber formation ( P < 0.001) and greater in DM ( P < 0.05). Expression of myogenin peaked later than MyoD ( P< 0.05); however, it did not differ between NM and DM. These data show that myostatin and MyoD increase coincidentally during formation of muscle fibers, indicating a coordinated role in the terminal differentiation and/or fusion of myoblasts. Myostatin mRNA is also consistently higher in DM than NM, suggesting that a feedback loop of regulation is also disrupted in the myostatin-deficient condition.

2020 ◽  
Author(s):  
Zhu Jin ◽  
Yutong Chen ◽  
Yuchen Mao ◽  
Mingjuan Gao ◽  
Zebing Zheng ◽  
...  

Abstract Background: microRNAs have been studied widely in hepatoblastoma. However, the role of miR-125b-5p and its relationship with the lncRNA sNEAT1 and YES1 in hepatoblastoma have not been reported previously. We aimed to reveal the role of NEAT1/miR-125b-5p/YES1 in the progression of hepatoblastoma.Methods: We collected tumor tissues and their adjacent tissues from 12 hepatoblastoma patients. qRT-PCR was applied to detect the expression of miR-125b-5p, and the relationship of miR-125b-5p with clinicopathological characteristics was analyzed. Dual luciferase reporter assays and RNA pull down assays were used to identify the relationships among NEAT1, miR-125b-5p and YES1. CCK8, Transwell assays and wound healing assays were used to examine cell viability, invasion and migration. In vivo experiments were also applied to detect the effect of miR-125b-5p on hepatoblastoma.Results: miR-125b-5p was significantly downregulated in hepatoblastoma tissue and cells. The higher the PRETEXT grade, the lower the miR-125b-5p level. NEAT1 could bind to miR-125b-5p and inhibit its expression. miR-125b-5p could target YES1 and inhibit its expression. Overexpression of miR-125b-5p decreased the proliferation, invasion, and migratory ability of hepatoblastoma cells. YES1 could rescue the above effects. At the same time, overexpression of miR-125b-5p resulted in decreased YES1 and tumor growth inhibition in vivo.Conclusion: miR-125b-5p acted as a shared miRNA of NEAT1 and YES1 in hepatoblastoma. Overexpression of miR-125b-5p could target YES1 and inhibit its expression, therefore inhibiting the progression of hepatoblastoma.


1998 ◽  
Vol 275 (2) ◽  
pp. R502-R508 ◽  
Author(s):  
Xianzhong Meng ◽  
Lihua Ao ◽  
Daniel R. Meldrum ◽  
Brian S. Cain ◽  
Brian D. Shames ◽  
...  

Exogenous tumor necrosis factor-α (TNF-α) induces delayed myocardial depression in vivo but promotes rapid myocardial depression in vitro. The temporal relationship between endogenous TNF-α and endotoxemic myocardial depression is unclear, and the role of TNF-α in this myocardial disorder remains controversial. Using a rat model of endotoxemia not complicated by shock, we sought to determine 1) the temporal relationship of changes in circulating and myocardial TNF-α with myocardial depression, 2) the influences of protein synthesis inhibition or immunosuppression on TNF-α production and myocardial depression, and 3) the influence of neutralization of TNF-α on myocardial depression. Rats were treated with lipopolysaccharide (LPS, 0.5 mg/kg ip). Circulating and myocardial TNF-α increased at 1 and 2 h, whereas myocardial contractility was depressed at 4 and 6 h. Pretreatment with cycloheximide or dexamethasone abolished the increase in circulating and myocardial TNF-α and preserved myocardial contractile function. Similarly, treatment with TNF binding protein immediately after LPS prevented myocardial depression. We conclude that endogenous TNF-α mediates delayed myocardial depression in endotoxemic rats and that inhibition of TNF-α production or neutralization of TNF-α preserves myocardial contractile function in endotoxemia.


2013 ◽  
Vol 33 (2) ◽  
Author(s):  
Carlo Follo ◽  
Matteo Ozzano ◽  
Claudia Montalenti ◽  
Massimo Mattia Santoro ◽  
Ciro Isidoro

CD (cathepsin D) is a ubiquitous lysosomal hydrolase involved in a variety of pathophysiological functions, including protein turnover, activation of pro-hormones, cell death and embryo development. CD-mediated proteolysis plays a pivotal role in tissue and organ homoeostasis. Altered expression and compartmentalization of CD have been observed in diseased muscle fibres. Whether CD is actively involved in muscle development, homoeostasis and dystrophy remains to be demonstrated. Zebrafish (Danio rerio) is emerging as a valuable ‘in vivo’ vertebrate model for muscular degeneration and congenital myopathies. In this work, we report on the perturbance of the somitic musculature development in zebrafish larvae caused by MPO (morpholino)-mediated silencing of CD in oocytes at the time of fertilization. Restoring CD expression, using an MPO-non-matching mutated mRNA, partially rescued the normal phenotype, confirming the indispensable role of CD in the correct development and integrity of the somitic musculature. This is the first report showing a congenital myopathy caused by CD deficiency in a vertebrate experimental animal model.


2018 ◽  
Vol 315 (4) ◽  
pp. L563-L575 ◽  
Author(s):  
Hua Jiang ◽  
Yingzhun Chen ◽  
Tong Yu ◽  
Xiaoguang Zhao ◽  
Huitong Shan ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with increasing mortality and poor prognosis. The current understanding of the role of long noncoding RNAs (lncRNAs) in IPF remains limited. In the present study, we identified a lncRNA NONMMUT022554, designated pulmonary fibrosis-regulatory lncRNA (PFRL), with unknown functions and found that its levels were increased in fibrotic lung tissues of mice and pulmonary fibroblasts exposed to transforming growth factor (TGF)-β1. Furthermore, we found that enforced expression of PFRL induced fibroblast activation and collagen deposition, which could be mitigated by the overexpression of microRNA (miR)-26a. By contrast, the inhibition of PFRL could markedly alleviate the TGF-β1-induced upregulation of fibrotic markers and attenuate fibroblast proliferation and differentiation by regulating miR-26a. Meanwhile, our study confirmed that PFRL inhibited the expression and activity of miR-26a, which has been identified as an antifibrotic miRNA in our previous study. Interestingly, our molecular study further confirmed that Smad2 transcriptionally inhibits the expression of miR-26a and that the miR-26a/Smad2 feedback loop mediates the profibrotic effects of PFRL in lung fibrosis. More importantly, knockdown of PFRL ablated bleomycin-induced pulmonary fibrosis in vivo. Taken together, our findings indicate that lncRNA PFRL contributes to the progression of lung fibrosis by modulating the reciprocal repression between miR-26a and Smad2 and that this lncRNA may be a therapeutic target for IPF.


2022 ◽  
Vol 20 (1) ◽  
Author(s):  
Li Song ◽  
Bin Luan ◽  
Qingrong Xu ◽  
Ruihe Shi ◽  
Xiufang Wang

Abstract Objective Exosomes, membranous nanovesicles, naturally bringing proteins, mRNAs, and microRNAs (miRNAs), play crucial roles in tumor pathogenesis. This study was to investigate the role of miR-155-3p from M2 macrophages-derived exosomes (M2-Exo) in promoting medulloblastoma (MB) progression by mediating WD repeat domain 82 (WDR82). Methods miR-155-3p expression was detected by RT-qPCR. The relationship of miR-155-3p with clinicopathological features of MB patients was analyzed. M2-Exo were isolated and identified by TEM, NTA and Western blot. CCK-8 assay, colony formation assay, flow cytometry, wound healing assay, and Transwell assay were performed to explore the role of miR-155-3p-enriched M2-Exo on the progression of MB cells. Luciferase assay were used to identify the relationship between miR-155-3p and WDR82. The effect of miR-155-3p-enriched M2-Exo on tumorigenesis of MB was confirmed by the xenograft nude mice model. Results miR-155-3p was up-regulated in MB tissues of patients and MB cell lines. High miR-155-3p expression was correlated with the pathological type and molecular subtype classification of MB patients. WDR82 was a direct target of miR-155-3p. miR-155-3p was packaged into M2-Exo. miR-155-3p-enriched M2-Exo promoted the progression of Daoy cells. miR-155-3p-enriched M2-Exo promoted in vivo tumorigenesis. Conclusion The study highlights that miR-155-3p-loaded M2-Exo enhances the growth of MB cells via down-regulating WDR82, which might provide a deep insight into MB mechanism.


Glycobiology ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 110-123 ◽  
Author(s):  
Laurino Carmen ◽  
Vadala’ Maria ◽  
Julio Cesar Morales-Medina ◽  
Annamaria Vallelunga ◽  
Beniamino Palmieri ◽  
...  

Abstract Duchenne muscular dystrophy (DMD) is an inherited fatal X-linked myogenic disorder with a prevalence of 1 in 3500 male live births. It affects voluntary muscles, and heart and breathing muscles. DMD is characterized by continuous degeneration and regeneration cycles resulting in extensive fibrosis and a progressive reduction in muscle mass. Since the identification of a reduction in dystrophin protein as the cause of this disorder, numerous innovative and experimental therapies, focusing on increasing the levels of dystrophin, have been proposed, but the clinical improvement has been unsatisfactory. Dystrophin forms the dystrophin-associated glycoprotein complex and its proteins have been studied as a promising novel therapeutic target to treat DMD. Among these proteins, cell surface glycosaminoglycans (GAGs) are found almost ubiquitously on the surface and in the extracellular matrix (ECM) of mammalian cells. These macromolecules interact with numerous ligands, including ECM constituents, adhesion molecules and growth factors that play a crucial role in muscle development and maintenance. In this article, we have reviewed in vitro, in vivo and clinical studies focused on the functional role of GAGs in the pathophysiology of DMD with the final aim of summarizing the state of the art of GAG dysregulation within the ECM in DMD and discussing future therapeutic perspectives.


2014 ◽  
Author(s):  
Isabelle Hatfield ◽  
Innocence Harvey ◽  
Erika R. Yates ◽  
JeAnna R. Redd ◽  
Lawrence T. Reiter ◽  
...  

Myogenesis is an important process during both development and muscle repair. Previous studies suggest that mTORC1 plays a role in the formation of mature muscle from immature muscle precursor cells. Here we show that gene expression for several myogenic transcription factors including Myf5, Myog and Mef2c but not MyoD and myosin heavy chain isoforms decrease when C2C12 cells are treated with rapamycin, supporting a role for mTORC1 pathway during muscle development. To investigate the possibility that mTORC1 can regulate muscle in vivo we ablated the essential dTORC1 subunit Raptor in Drosophila melanogaster and found that muscle-specific knockdown of Raptor causes flies to be too weak to emerge from their pupal cases during eclosion. Using a series of GAL4 drivers we also show that muscle-specific Raptor knockdown also causes shortened lifespan, even when eclosure is unaffected. Together these results highlight an important role for TORC1 in muscle development, integrity and function in both Drosophila and mammalian cells.


Blood ◽  
2011 ◽  
Vol 117 (2) ◽  
pp. 630-637 ◽  
Author(s):  
Thomas B. Bartnikas ◽  
Nancy C. Andrews ◽  
Mark D. Fleming

AbstractAs a central regulator of iron metabolism, hepcidin inhibits dietary iron absorption and macrophage iron recycling. Its expression is regulated by multiple factors including iron availability and erythropoietic activity. To investigate the role of transferrin (Tf) in the regulation of hepcidin expression by these factors in vivo, we employed the hypotransferrinemic (hpx) mouse. These Tf-deficient mice have severe microcytic anemia, tissue iron overload, and hepcidin deficiency. To determine the relationship of Tf levels and erythropoiesis to hepcidin expression, we subjected hpx mutant and control mice to a number of experimental manipulations. Treatment of hpx mice with Tf injections corrected their anemia and restored hepcidin expression. To investigate the effect of erythropoiesis on hepcidin expression, we suppressed erythropoiesis with blood transfusions or myeloablation with chemotherapeutic drugs. Transfusion of hpx animals with wild-type red blood cells led to increased hepcidin expression, while hepcidin expression in myeloablated hpx mice increased only if Tf was administered postablation. These results suggest that hepcidin expression in hpx mice is regulated both by Tf-restricted erythropoiesis and by Tf through a mechanism independent of its role in erythropoiesis.


1978 ◽  
Vol 235 (5) ◽  
pp. C199-C203 ◽  
Author(s):  
W. W. Hofmann ◽  
J. Butte ◽  
H. A. Leon

Attempts have been made to evaluate the role of intracellular creatine in conditions leading to increased or decreased amounts of contractile protein in rat skeletal muscles. Resting concentrations of intracellular creatine ([Cr]i) and creatine phosphate ([CrP]i) were compared in gastrocnemius and soleus muscles with those immediately after a 20-s tetanic stimulation. The hydrolysis of creatine phosphate was the same after heavily and lightly loaded contractions, suggesting that hypertrophy of isometric exercise is not mediated by creatine. With atrophy after denervation or interruption of sciatic axoplasmic flow [Cr]i also remained unchanged, though [CrP]i and the rate of Cr uptake fell after denervation. The major change in adult red and white muscle bulk with unaltered [Cr]i suggests that the Cr sensitivity found by others in developing muscle in vitro has been supplemented or replaced by other control mechanisms.


2019 ◽  
Vol 28 (24) ◽  
pp. 4186-4196 ◽  
Author(s):  
Mo Zhao ◽  
Lindsay Smith ◽  
Jonathan Volpatti ◽  
Lacramioara Fabian ◽  
James J Dowling

Abstract Dynamin 2 (DNM2) encodes a ubiquitously expressed large GTPase with membrane fission capabilities that participates in the endocytosis of clathrin-coated vesicles. Heterozygous mutations in DNM2 are associated with two distinct neuromuscular disorders, Charcot–Marie–Tooth disease (CMT) and autosomal dominant centronuclear myopathy (CNM). Despite extensive investigations in cell culture, the role of dynamin 2 in normal muscle development is poorly understood and the consequences of DNM2 mutations at the molecular level in vivo are not known. To address these gaps in knowledge, we developed transgenic zebrafish expressing either wild-type dynamin 2 or dynamin 2 with either a CNM or CMT mutation. Taking advantage of the live imaging capabilities of the zebrafish embryo, we establish the localization of wild-type and mutant dynamin 2 in vivo, showing for the first time distinctive dynamin 2 subcellular compartments. Additionally, we demonstrate that CNM-related DNM2 mutations are associated with protein mislocalization and aggregation. Lastly, we define core phenotypes associated with our transgenic mutant fish, including impaired motor function and altered muscle ultrastructure, making them the ideal platform for drug screening. Overall, using the power of the zebrafish, we establish novel insights into dynamin 2 localization and dynamics and provide the necessary groundwork for future studies examining dynamin 2 pathomechanisms and therapy development.


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