Proteomic Studies on the Mechanism of Myostatin Regulating Cattle Skeletal Muscle Development

Myostatin (MSTN) is an important negative regulator of muscle growth and development. In this study, we performed comparatively the proteomics analyses of gluteus tissues from MSTN+/− Mongolian cattle (MG.MSTN+/−) and wild type Mongolian cattle (MG.WT) using a shotgun-based tandem mass tag (TMT) 6-plex labeling method to investigate the regulation mechanism of MSTN on the growth and development of bovine skeletal muscle. A total of 1,950 proteins were identified in MG.MSTN+/− and MG.WT. Compared with MG.WT cattle, a total of 320 differentially expressed proteins were identified in MG.MSTN cattle, including 245 up-regulated differentially expressed proteins and 75 down-regulated differentially expressed proteins. Bioinformatics analysis showed that knockdown of the MSTN gene increased the expression of extracellular matrix and ribosome-related proteins, induced activation of focal adhesion, PI3K-AKT, and Ribosomal pathways. The results of proteomic analysis were verified by muscle tissue Western blot test and in vitro MSTN gene knockdown test, and it was found that knockdown MSTN gene expression could promote the proliferation and myogenic differentiation of bovine skeletal muscle satellite cells (BSMSCs). At the same time, Co-Immunoprecipitation (CO-IP) assay showed that MSTN gene interacted with extracellular matrix related protein type I collagen α 1 (COL1A1), and knocking down the expression of COL1A1 could inhibit the activity of adhesion, PI3K-AKT and ribosome pathway, thus inhibit BSMSCs proliferation. These results suggest that the MSTN gene regulates focal adhesion, PI3K-AKT, and Ribosomal pathway through the COL1A1 gene. In general, this study provides new insights into the regulatory mechanism of MSTN involved in muscle growth and development.

Comparison of Nutritional and Meat Quality Characteristics between Two Primal Cuts from Aceh Cattle in Aceh Province, Indonesia

The Aceh cattle are local Indonesian beef cattle that are farmed in Aceh Province. This type of cattle is one of the sources of meat for the Aceh people. This study aims to analyze the quality of two primal cuts (longissimus lumborum and semitendinosus muscle) from Aceh cattle based on the muscle microstructure characteristics and MSTN gene expression. This study used a sample of longissimus lumborum and semitendinosus muscles from 18 adult male Aceh cattle with the age of 2–2.5 years and a BCS of 3.24. Muscle samples were obtained shortly after the cattle were slaughtered in slaughterhouses in Banda Aceh and Aceh Besar districts. Muscle microstructure analysis was performed using the HE, Masson’s trichrome, and immunohistochemistry staining methods, while the MSTN gene expression analysis was performed using the qPCR method. The analysis of the physical quality of meat includes pH, meat color, fat color, cooking loss, water holding capacity, and WBSF value. The results showed that the area of LL muscle fibers was smaller than that of ST with relatively the same diameter. Both muscles were dominated by fast fibers with a percentage of 82.37% (LL muscle) and 91.80% (ST muscle). The area and composition of the type of muscle fibers are the main factors that influence the tenderness of Aceh beef. A higher distribution of collagen was found in ST muscles than in LL muscles. MSTN gene expression in both muscle types was relatively the same. Aceh cattle have large muscle fibers and are dominated by fast fibers with a high percentage, resulting in a low level of the tenderness of Aceh beef. However, the level of tenderness of Aceh beef is still in accordance with the cooking preparation of original and favorite cuisine of Aceh people.

Interaction of Fibromodulin and Myostatin to Regulate Skeletal Muscle Aging: An Opposite Regulation in Muscle Aging, Diabetes, and Intracellular Lipid Accumulation

The objective of this study was to investigate fibromodulin (FMOD) and myostatin (MSTN) gene expressions during skeletal muscle aging and to understand their involvements in this process. The expressions of genes related to muscle aging (Atrogin 1 and Glb1), diabetes (RAGE and CD163), and lipid accumulation (CD36 and PPARγ) and those of FMOD and MSTN were examined in CTX-injected, aged, MSTN−/−, and high-fat diet (HFD) mice and in C2C12 myoblasts treated with ceramide or grown under adipogenic conditions. Results from CTX-injected mice and gene knockdown experiments in C2C12 cells suggested the involvement of FMOD during muscle regeneration and myoblast proliferation and differentiation. Downregulation of the FMOD gene in MSTN−/− mice, and MSTN upregulation and FMOD downregulation in FMOD and MSTN knockdown C2C12 cells, respectively, during their differentiation, suggested FMOD negatively regulates MSTN gene expression, and MSTN positively regulates FMOD gene expression. The results of our in vivo and in vitro experiments indicate FMOD inhibits muscle aging by negatively regulating MSTN gene expression or by suppressing the action of MSTN protein, and that MSTN promotes muscle aging by positively regulating the expressions of Atrogin1, CD36, and PPARγ genes in muscle.

MYOSTATIN COORDINATING THE PROLIFERATION AND DIFFERENTIATION OF ADIPOSE AND SKELETAL MUSCLE CELLS AND ENERGY METABOLISM BALANCE BASED ON GENE CHIP TECHNOLOGY

ABSTRACT Myoblasts fuse into multinucleated muscle fibers to form and promote the growth of skeletal muscle. In order to analyze the role of myostatin (MSTN) in body fat, skeletal muscle cell proliferation and differentiation and energy metabolism, this study will use the antisense RNA technology of gene chip technology to study it. The results showed that the MSTN gene regulated the growth and proliferation of myoblasts and affected the development of skeletal muscle by affecting the expression of Cdc42, bnip2, p38 and other genes; knockout or overexpression of the MSTN gene would lead to a trend of fat-related genes from fat synthesis to fat decomposition; after the MSTN gene was knocked down, the expression levels of cpti-b, PPARG and other genes in the cells were corresponding after MSTN overexpression, the relative expression of the PPARG gene decreased. It is suggested that the knockout or overexpression of MSTN may affect lipid accumulation, and cpti-b and PPARG may directly regulate lipid level. It is hoped that this experiment can provide a reference for the study of MSTN effect on fat deposition.

Genetic variation in the first intron and exon of the myostatin gene in several Indonesian cattle populations

Background and Aim: Myostatin (MSTN), a member of the transforming growth factor-β family, is a negative regulator of muscle mass. This study aimed to detect the genetic variation of the 1160 bp fragment of exon 1 and part of intron 1 of the MSTN gene in several cattle populations raised in Indonesia. Materials and Methods: Polymerase chain reaction products of the MSTN gene amplified from 92 animals representing 10 cattle populations (Peranakan Ongole [PO], Belgian Blue x PO cross, Rambon, PO x Bali cross, Jabres, Galekan, Sragen, Donggala, Madura, and Bali) were sequenced, compared, and aligned with bovine MSTN of Bos taurus (GenBank Acc. No. AF320998.1) and Bos indicus (GenBank Acc. No. AY794986.1). Results: Four nucleotide substitutions (nt 1045 and 1066 in intron 1; nt 262 and 418 in exon 1) and two indels (nt 807 and 869 in intron 1) were synonymous mutations. Among these substitutions, only the nt 262G>C and nt 418A>G loci were polymorphic in all populations, except Bali cattle. The frequencies of the nt 262C (0.82) and nt 418A (0.65) alleles were highest. For the nt 262G>C locus, the CC genotype had the highest frequency (0.66) followed by GC (0.30) and CC (0.03). For the nt 418A>G locus, the AG genotype had the highest frequency (0.52) followed by AA (0.39) and GG (0.09). Conclusion: The results, showing genetic variations in exon 1 and intron 1 of the MSTN gene, might be helpful for future association studies.

Variants in the Myostatin Gene and Physical Performance Phenotype of Elite Athletes

The MSTN gene is a negative regulator of muscle growth that is attracting attention as a candidate gene for physical performance traits. We hypothesised that variants of MSTN might be associated with the status of elite athlete. We therefore sought to study the potential role of MSTN in the physical performance of athletes by analysing the whole coding sequence of the MSTN gene in a cohort of Lithuanian elite athletes (n = 103) and non-athletes (n = 127). Consequently, two genetic variants were identified: the deletion of one of three adenines in the first intron (c.373+90delA, rs11333758) and a non-synonymous variant in the second exon (c.458A>G, p.Lys(K)153Arg(R), rs1805086). Among all samples, the MSTN rs1805086 Lys(K) allele was the most common form in both groups. Homozygous genotype for the less common Arg(R) allele was identified in only one elite canoe rower, and we could find no direct association between rs1805086 and successful results in elite athletes. Surprisingly, the intronic variant (rs11333758) was abundant among all samples. The main finding was that endurance-oriented athletes had 2.1 greater odds of being MSTN deletion genotype than non-athletes (13.6% vs. 0.8%). The present study confirms the association of the polymorphism rs11333758 with endurance performance status in Lithuanian elite athletes.

Myostatin Gene as a Genetic Marker for Growth and Carcass Traits in Beef Cattle

<p>Growth and carcass traits are of economic importances in livestock breeding, because they affect the profitability of animal production. The phenotypic expression of these traits is controlled by multiple genes (polygenes), such as myostatin (MSTN) gene. This paper aims to discuss the expression, polymorphism and potential application of MSTN gene as a marker-assisted selection (MAS) for growth and carcass traits in beef cattle based on data from published studies. MSTN gene or known as growth and differentiation factor 8 (GDF8) is a member of the transforming growth factor-β (TGF-β) superfamily, which acts as a negative regulator of skeletal muscle mass deposition. Several published studies showed that mutations in the MSTN gene can inhibit the activation of myostatin, which leads to an increased muscle mass (hypertrophy). Several <em>MSTN</em> gene polymorphisms were reported to be associated with growth and carcass traits in local cattle in several countries, including Indonesia, namely Bali cattle. Based on several assumptions: 1) there is MTSN gene polymorphisms in a population, 2) there is a significant association between MSTN gene polymorphisms and growth and carcass traits, as reported in several beef cattle populations and 3) those cattle with superior genotype have better growth performances, we expect that there will be improvement in growth performances in the future if those cattle are selected. Understanding MSTN gene polymorphisms would be useful to make strategies for the genetic improvement for growth and carcass traits of local cattle.</p>