Expression Of MSTN Research Articles

Titanium decorated iron oxide (Ti@Fe2O3) regulates the proliferation of bovine muscle satellite cells through oxidative stress

In the present study, the titanium decorated iron oxide (Ti@Fe2O3) nanocomposites are synthesized using the chemical method. The as-prepared nanocomposite was characterized for successful formulation and the elemental spectra showed the composition of Fe (44%), Ti (0.71%) and O (55%) is confirmed the homogenous distribution. Crystallographic spectra depict the strong peaks corresponding to the of TiO2 and Fe2O3 nanoparticles planes with minor shift variation due to the formulation of Ti on the surface of Fe2O3 nanoparticles and it is also confirmed with SAED analysis. The X-ray photoelectron spectroscopy (XPS) analysis of Ti@Fe2O3) nanocomposite confirms the existence of elements such as Fe, O and Ti. Further, the morphology of the composite showed the well-defined encapsulation and aggregation of TiO2 nanoparticles on the surface of Fe2O3 nanoparticles. Further, the TiO2 nanoparticles showed less cytotoxic activity against bovine satellite cells, as well the nanocomposite increased the growth of bovine satellite cells comparing with control cells. Further, the morphological analysis showed the significant changes in TiO2 nanoparticles treated cells and the nanocomposite induces the myotube formation due to the increased ROS level in bovine satellite cells. Moreover, the nanocomposite regulates the expression of genes IGF-1, TGF-β, MSTN, CASP3, CASP2 and proteins such as CALP1, CALP2, MyoD, MyoG which are responsible for the growth, proliferation, and differentiation of satellite cells. Together, the prepared Ti@Fe2O3 nanocomposites afford additional support for the applications of nanomaterials in skeletal muscle repair and tissue regeneration engineering.

Berberine Down-Regulated Myostatin Expression and Facilitated Metabolism via Smad Pathway in Insulin Resistant Mice.

ObjectiveTo explore the effect of berberine (BBR) on skeletal muscle mass and metabolism and the possible mechanism.MethodsEight-week-old male C57BL/6 mice were fed with a high-fat diet (HFD) for 8 weeks to establish the insulin resistance obesity model. Then, mice were randomly divided into two groups (normal chow diet (NCD) and HFD), while NCD and HFD were further classified into two groups respectively, which were NCD+CS (Carmellose Sodium), NCD+BBR, HFD+CS and HFD+BBR. After the BBR intervention, insulin tolerance test (ITT) and glucose tolerance test (GTT) were carried out. Metabolic parameters and inflammatory biomarkers were detected. Various parts of adipose tissue and gastrocnemius were separated and measured. The gastrocnemius muscle was selected for tissue staining. The mRNA expression of myostatin (Mstn) was tested by quantitative real-time PCR (RT-PCR). Western blotting was performed to detect the expression of Mstn, phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), small ribonucleoprotein particle protein 2 (Smd2), small ribonucleoprotein particle protein 3 (Smd3), and small ribonucleoprotein particle protein 4 (Smd4).ResultsBoth body weights (P<0.01) and various parts of fat mass (P<0.001) were decreased significantly, while muscle mass was increased in the HFD group after being treated with BBR. Meanwhile, the glucose and lipid metabolic disorders as well as inflammation status were improved. RT-PCR and Western blotting analysis showed that, after being fed with HFD the expression of Mstn mRNA and Mstn were significantly increased, and decreased after being treated with BBR. Western blotting analysis also showed that, compared with the NCD group, the expressions of Smad2, Smad3, and Smad4 were all increased in the HFD group, but after being treated with BBR, the expressions of Smad3 and Smad4 were decreased.ConclusionOur study revealed that BBR could improve metabolic disorders and inflammation status, decrease Mstn expression, and increase skeletal muscle mass, which was associated with the Smad pathway.

Improvac immunocastration affects the development of thigh muscles but not pectoral muscles in male chickens

Improvac has been tentatively used to immune-castrate roosters. The aim of this study was to investigate whether Improvac affected skeletal muscle development in chickens. The muscle fiber type and size and the expression levels of genes related to muscle development in pectoral and thigh muscles were examined at 5, 9, and 14 wk of age in the control, early, late, and early + late Improvac-treated groups. Immunocastration with Improvac affected the development of thigh muscles and the expression of MYH1B, MSTN, and SM. The cross-sectional area in the early group was significantly larger than in the control group at the 14th week (P < 0.01). At the fifth week, the expression levels of MYH1B, MYOD, and MSTN in the early group were significantly higher than those in the control group (P < 0.05), and at the ninth week, the expression level of SM1 in the control group was significantly lower than that in early and late groups (P < 0.05). Immunocastration did not affect pectoral muscle development or the expression of genes related to muscle development.

Integrative phenotypic and gene expression data identify myostatin as a muscle growth inhibitor in Chinese shrimp Fenneropenaeus chinensis

Growth traits, largely determined by muscle growth, are the most critical economic traits in shrimp breeding. Myostatin (Mstn) is a conserved inhibitor of muscle growth in vertebrates, but until now solid evidence supporting a similar function of Mstn in invertebrates has been lacking. In the present study, we examined the Mstn expression along with growth trait data in a Fenneropenaeus chinensis population, to establish a potential correlation between Mstn and growth. The heritabilities of FcMstn expression, body weight at 190 days of culture, body weight and length at 230 days of culture, and average daily gain were estimated using 773 individuals and a thirteen-generation pedigree. The results showed FcMstn expression was negatively correlated with the growth traits, and the mean FcMstn expression in females was significantly lower than that of males, indicating Mstn negatively regulates muscle growth in shrimp, and its lower expression may underscore the faster growth of females. Low heritabilities were detected for FcMstn expression, suggesting that the expression of Mstn might be heritable in shrimp. These results provide strong support for a growth inhibitory function of Mstn in F. chinensis, and suggest a potential method for selective breeding of this species without substantial experimental resources and labor force.

Myostatin in the Arterial Wall of Patients with End-Stage Renal Disease.

Aim: Myostatin (Mstn) has been described as a trigger for the progression of atherosclerosis. In this study, we evaluated the role of Mstn in arterial remodeling in patients with end-stage renal disease (ESRD).Methods: Vascular specimens were collected from 16 ESRD patients (56.4 ± 7.9 years) undergoing renal transplant (recipients) and 15 deceased kidney non-uremic donors (55.4 ± 12.1 years). We studied gene and protein expression of Mstn, ubiquitin ligases, Atrogin-1, and muscle ring finger protein-1 (MuRF-1), inflammatory marker CCL2, cytoskeleton components, and Klotho by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. Moreover, we assessed vascular calcification and collagen deposition. Finally, we studied the effects of recombinant Mstn on rat vascular smooth muscle cells (VSMCs, A7r5) and evaluated the effects of uremic serum (US) on primary human VSMCs.Results: Myostatin mRNA was upregulated in the arterial vascular wall of recipients compared with donors (∼15-folds, p < 0.05). This response was accompanied by the upregulation of gene expression of Atrogin-1 and MuRF-1 (+2.5- and +10-fold) and CCL2 (+3-fold). Conversely, we found downregulation of protein expression of Smoothelin, α-smooth muscle actin (α-SMA), vimentin, and Klotho (−85%, −50%, −70%, and −80%, respectively; p < 0.05) and gene expression of vimentin and Klotho. Exposition of A7r5 to Mstn induced a time-dependent SMAD 2/SMAD 3 phosphorylation and expression of collagen-1 and transforming growth factor β (TGFβ) mRNA, while US induced overexpression of Mstn and Atrogin-1 and downregulation of Smoothelin and Klotho.Conclusions: Our data suggest that uremia might induce vascular Mstn gene expression together with a complex pathway of molecular and structural changes in the vascular wall. Myostatin, in turn, can translate the metabolic alterations of uremia into profibrotic and stiffness inducing signals.

Effect of maternal nutrient restriction on skeletal muscle mass and associated molecular pathways in SGA and Non-SGA sheep fetuses

Maternal nutrient restriction causes small for gestational age (SGA) offspring, which exhibit a higher risk for metabolic syndrome in adulthood. Fetal skeletal muscle is particularly sensitive to maternal nutrient restriction, which impairs muscle mass and metabolism. Using a 50% nutrient restriction treatment from gestational day (GD) 35 to GD 135 in sheep, we routinely observe a spectral phenotype of fetal weights within the nutrient-restricted (NR) group. Thus, our objective was to evaluate the effect of maternal NR on muscle mass, myofiber hypertrophy, myonuclear dotation, and molecular markers for protein synthesis and degradation, while accounting for the observed fetal weight variation. Within the NR group, we classified upper-quartile fetuses into NR(Non-SGA) (n = 11) and lower-quartile fetuses into NR(SGA) (n = 11). A control group (n = 12) received 100% of nutrient requirements throughout pregnancy. At GD 135, fetal plasma and organs were collected, and gastrocnemius and soleus muscles were sampled for investigation. Results showed decreased (P < 0.05) absolute tissue/organ weights, including soleus and gastrocnemius muscles, in NR(SGA) fetuses compared to NR(Non-SGA) and control. Myofiber cross-sectional area was smaller in NR(SGA) vs control for gastrocnemius (P = 0.0092) and soleus (P = 0.0097) muscles. Within the gastrocnemius muscle, the number of myonuclei per myofiber was reduced (P = 0.0442) in NR(SGA) compared to control. Cortisol may induce protein degradation. However, there were no differences in fetal cortisol among groups. Nevertheless, for gastrocnemius muscle, cortisol receptor (NR3C1; P = 0.0124), and FOXO1 (P = 0.0131) were upregulated in NR(SGA) compared to control while NR(Non-SGA) did not differ from the other 2 groups. KLF15 was upregulated (P = 0.0002) in both NR(SGA) and NR(Non-SGA); while FBXO32, TRIM63, BCAT2 or MSTN did not differ. For soleus muscle, KLF15 mRNA was upregulated (P = 0.0145) in NR(SGA) compared to control, and expression of MSTN was increased (P = 0.0259) in NR(SGA) and NR(Non-SGA) compared to control. At the protein level, none of the mentioned molecules nor total ubiquitin-labeled proteins differed among groups (P > 0.05). Indicators of protein synthesis (total and phosphorylated MTOR, EI4EBP1, and RPS6KB1) did not differ among groups in either muscle (P > 0.05). Collectively, results highlight that maternal NR unequally affects muscle mass in NR(SGA) and NR(Non-SGA) fetuses, and alterations in myofiber cross-sectional area and myonuclei number partially explain those differences.

A high-content cytokine screen identifies myostatin propeptide as a positive regulator of primitive chronic myeloid leukemia cells.

Aberrantly expressed cytokines in the bone marrow (BM) niche are increasingly recognized as critical mediators of survival and expansion of leukemic stem cells. To identify regulators of primitive chronic myeloid leukemia (CML) cells, we performed a high-content cytokine screen using primary CD34+ CD38low chronic phase CML cells. Out of the 313 unique human cytokines evaluated, 11 were found to expand cell numbers ≥2-fold in a 7-day culture. Focusing on novel positive regulators of primitive CML cells, the myostatin antagonist myostatin propeptide gave the largest increase in cell expansion and was chosen for further studies. Herein, we demonstrate that myostatin propeptide expands primitive CML and normal BM cells, as shown by increased colony-forming capacity. For primary CML samples, retention of CD34-expression was also seen after culture. Furthermore, we show expression of MSTN by CML mesenchymal stromal cells, and that myostatin propeptide has a direct and instant effect on CML cells, independent of myostatin, by demonstrating binding of myostatin propeptide to the cell surface and increased phosphorylation of STAT5 and SMAD2/3. In summary, we identify myostatin propeptide as a novel positive regulator of primitive CML cells and corresponding normal hematopoietic cells.

Effects of neuromuscular electrical stimulation on muscle atrophy and muscle fiber composition in quadriceps muscles of chronic obstructive pulmonary disease rats

Objective To investigate the effect of neuromuscular electrical stimulation(NMES)on muscle atrophy and muscle fiber type conversion in quadriceps muscles of rats with chronic obstructive pulmonary disease(COPD). Methods Forty-eight male SPF Wistar rats were randomly divided into three groups: the healthy control group, COPD model group and NMES treatment group, with sixteen rats in each group.Rats in the NMES treatment group were given alternating electrical stimulation at 100 Hz and 2 Hz, with each stimulation time of 30 min, 7 days per week, for 4 weeks.The control group and the COPD model group were only treated with electrode sheets.After the intervention, the endurance running distance measurement, the pathological changes of rat quadriceps muscle detected by HE staining, the mRNA and protein content of MSTN, MyHC(Myosin Heavy Chain)-Ⅰ, MyHC-Ⅱa and MyHC-Ⅱx in quadriceps muscles determined by Realtime PCR and Western Blot were performed. Results Compared with the healthy control group, the cross-sectional area, endurance running distance and MyHC-Ⅰ mRNA and protein expressions in the quadriceps muscles were decreased[(654.7±53.7) μm2vs.(1079.8±117.2) μm2, (396.7±42.4) m vs.(607.4±56.3) m, 0.407±0.054 vs.0.997±0.069, 0.884±0.102 vs.1.723±0.156, t=4.642, 3.785, 24.723 and 18.640, P=0.008, 0.033, 0.000 and 0.000, respectively], while MSTN, MyHC-Ⅱa and MyHC-Ⅱx mRNA and protein expressions were increased in the COPD model group(all P<0.01). Compared with COPD model, the cross-sectional area(997.5±92.4 μm2), endurance running distance(597.2±65.8 m)and the expression levels of MyHC-ⅠmRNA(0.884±0.097)and protein(1.534±0.182)in the quadriceps muscles were increased(t=3.734, 3.602, 19.988 and 13.666, P=0.035, 0.043, 0.000, 0.000), and the mRNA and protein expression levels of MSTN, MyHC-Ⅱa and MyHC-Ⅱx were decreased in the NMES treatment group(all P<0.01). Further correlation analysis found that the protein expression of MSTN in the quadriceps muscles was negatively correlated with muscle cross-sectional area, MyHC-Ⅰprotein levels and endurance running distance(r=-0.724, -0.426 and -0.536, P=0.002, 0.036 and 0.007, respectively), and positively correlated with the protein expressions of MyHC-Ⅱa and MyHC-Ⅱx(r=0.408 and 0.392, P=0.042 and 0.048). Conclusions The expression of MSTN is increased in quadriceps muscle of COPD rats, and NMES can inhibit the expression of MSTN in quadriceps muscles.MSTN is associated with muscle atrophy and muscle fiber conversion in COPD.Inhibition of MSTN expression can improve muscle atrophy and reverse muscle fiber transformation. Key words: Pulmonary disease, chronic obstructive; Electric stimulation therapy; Muscular disorders, atrophic

Tocotrienol-Rich Fraction (TRF) Treatment Promotes Proliferation Capacity of Stress-Induced Premature Senescence Myoblasts and Modulates the Renewal of Satellite Cells: Microarray Analysis.

Human skeletal muscle is a vital organ involved in movement and force generation. It suffers from deterioration in mass, strength, and regenerative capacity in sarcopenia. Skeletal muscle satellite cells are involved in the regeneration process in response to muscle loss. Tocotrienol, an isomer of vitamin E, was reported to have a protective effect on cellular aging. This research is aimed at determining the modulation of tocotrienol-rich fraction (TRF) on the gene expressions of stress-induced premature senescence (SIPS) human skeletal muscle myoblasts (CHQ5B). CHQ5B cells were divided into three groups, i.e., untreated young control, SIPS control (treated with 1 mM hydrogen peroxide), and TRF-posttreated groups (24 hours of 50 μg/mL TRF treatment after SIPS induction). The differential gene expressions were assessed using microarray, GSEA, and KEGG pathway analysis. Results showed that TRF treatment significantly regulated the gene expressions, i.e., p53 (RRM2B, SESN1), ErbB (EREG, SHC1, and SHC3), and FoxO (MSTN, SMAD3) signalling pathways in the SIPS myoblasts compared to the SIPS control group (p < 0.05). TRF treatment modulated the proliferation capacity of SIPS myoblasts through regulation of ErbB (upregulation of expression of EREG, SHC1, and SHC3) and FoxO (downregulation of expression of MSTN and SMAD3) and maintaining the renewal of satellite cells through p53 signalling (upregulation of RRM2B and SESN1), MRF, cell cycle, and Wnt signalling pathways.

Myostatin knockout induces apoptosis in human cervical cancer cells via elevated reactive oxygen species generation

Myostatin (Mstn) is postulated to be a key determinant of muscle loss and cachexia in cancer. However, no experimental evidence supports a role for Mstn in cancer, particularly in regulating the survival and growth of cancer cells. In this study, we showed that the expression of Mstn was significantly increased in different tumor tissues and human cancer cells. Mstn knockdown inhibited the proliferation of cancer cells. A knockout (KO) of Mstn created by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) 9 (CRISPR/Cas9) induced mitochondria-dependent apoptosis in HeLa cells. Furthermore, KO of Mstn reduced the lipid content. Molecular analyses demonstrated that the expression levels of fatty acid oxidation-related genes were upregulated and then increased rate of fatty acid oxidation. Mstn deficiency-induced apoptosis took place along with generation of reactive oxygen species (ROS) and elevated fatty acid oxidation, which may play a role in triggering mitochondrial membrane depolarization, the release of cytochrome c (Cyt-c), and caspase activation. Importantly, apoptosis induced by Mstn KO was partially rescued by antioxidants and etomoxir, thereby suggesting that the increased level of ROS was functionally involved in mediating apoptosis. Overall, our findings demonstrate a novel function of Mstn in regulating mitochondrial metabolism and apoptosis within cancer cells. Hence, inhibiting the production and function of Mstn may be an effective therapeutic intervention during cancer progression and muscle loss in cachexia.

Low-intensity pulsed ultrasound prevents muscle atrophy induced by type 1 diabetes in rats

BackgroundType 1 diabetes mellitus (T1DM) induces serious skeletal muscle atrophy. Low-intensity pulsed ultrasound (LIPUS) is a common treatment for skeletal muscle injury and is effective in accelerating the rate of muscle growth. However, to the best of our knowledge, whether LIPUS can improve skeletal muscle atrophy in type 1 diabetic rats has not been investigated.MethodsThe rats were randomly divided into four groups: the normal control group (NC); the sham-treated diabetic control group (DC); the diabetic, insulin-treated group (DI) as a positive control; and the diabetic LIPUS therapy group (DL). The DL rats were treated with LIPUS (1 MHz, 30 mW/cm2) on the gastrocnemius for 20 min/day.ResultsAfter 6 weeks, the rats in the DC group showed severe muscle atrophy. However, LIPUS significantly improved type 1 diabetes-induced muscle atrophy, as evidenced by significantly enhanced muscle cross-sectional area, muscle mass, and strength. Moreover, compared with the DC group, LIPUS significantly activated Akt and upregulated the expression of mTOR, and LIPUS downregulated the expression of MSTN, its receptor ActRIIB, and FoxO1.ConclusionsThese results indicate that LIPUS improved muscle atrophy induced by type 1 diabetes, and the MSTN/Akt/mTOR&FoxO1 signaling pathway may play a role in this improvement.

Functional characteristic and differential expression of myostatin in Chlamys nobilis

ABSTRACTMyostatin (MSTN) was a conserved negative regulatory protein of muscle growth and development in numerous species. In this study, the MSTN gene was cloned and characterized from a noble scallop, Chlamys nobilis, and it was named CN-MSTN. To investigate the molecular characterization of MSTN and its gene expression profile of spatio-temporal, we isolated the MSTN cDNA sequence in C. nobilis and analysed expression patterns using quantitative real-time PCR. CN-MSTN cDNA contained a 1,374 bp open reading frame that encoded a 458 amino acids. Furthermore, the result of 3D model indicated that CN-MSTN mature peptide was similar to that of Chlamys farreri. Additionally, based on both the nucleotide and amino acid datasets, phylogenetic trees indicated that C. nobilis has the highest similarity with homologues of C. farreri. The expression patterns of different stages showed that MSTN expression was markedly higher in the gastrulae period. Additionally, remarkable expression of MSTN was observed in adductor muscle than with other tissues. Our data would provide expression and phylogenetic information of this economical important sea food, noble scallop.

Effects of Co-Transfection with Myostatin-Targeting siRNA and ActRIIB-Fc Fusion Protein on Skeletal Muscle Growth

Background: Myostatin (Mstn) is a secreted TGF-β family member that controls skeletal muscle growth, and binds with high affinity to the activin type IIB receptor (ActRIIB). The soluble ligand-binding domain of ActRIIB fused to the Fc domain of IgG (ActRIIB-Fc) potently binds and inhibits TGF-β family members in muscle, leading to rapid and marked muscle growth. The present study was designed to assess the combinative effects of myostatin-targeting siRNA (Mstn-siRNA) and ActRIIB-Fc on murine myoblast in vitro and in vivo. Materials and Methods: C2C12 cells were treated by Mstn-siRNA with or without ActRIIB-Fc at 0 and 48 h after differentiation. Myotube size was measured, and gene expression of Mstn, MuRF-1, MyoD and myogenin were analyzed. Furthermore, 11-week-old, male C57BL/6 mice were injected with atelocollagen (ATCOL)-mediated Mstn-siRNA and Mstn-siRNA/ActRIIB-Fc locally into the masseter muscle twice a week. Histological and biochemical analyses were performed using the dissected muscles. Results: Transfection of Mstn-siRNA and Mstn-siRNA/ActRIIB-Fc resulted in significant increases in the myotube diameter of the C2C12 cells compared with untreated control. Also, treatment with Mstn-siRNA and Mstn-siRNA/ActRIIB-Fc could lead to an upregulation of MyoD and myogenin gene expression and downregulation of Mstn and MuRF-1. In vivo, muscle fibril hypertrophy was observed in both Mstn-siRNA and Mstn-siRNA/ActRIIB-Fc treated groups. Moreover, western blotting analysis showed that the p-Smad2/3 expression level was decreased by treatment of Mstn-siRNA/ActRIIB-Fc. In contrast, MyoD and myogenin protein levels were increased by combined treatment, compared with the other groups. Conclusions: These suggest that double inhibition of myostain is potentially useful for myogenesis and muscle growth promotion. This may be a good as new treatment remedy for patients with various muscle atrophies, including muscular dystrophy.

CuInS2/ZnS QD exposure induces developmental toxicity, oxidative stress and DNA damage in rare minnow (Gobiocypris rarus) embryos and larvae

Chinese rare minnow (Gobiocypris rarus) embryos were used as an experimental model to investigate the effects of CuInS2/ZnS quantum dots (QDs) on the early life stages of G. rarus. Normal developmental parameters (survival rate, body length and average heart rate), biomarker genes [stress response (Hsp70), detoxification (Cyp1a), organizer function and axis formation (Wnt8α), and muscle (Mstn)], enzymatic activity and DNA damage were recorded as endpoints in the developing embryos/larvae after exposure until 96h post-fertilization (hpf). Reduced survival rate, decreased heart rate, altered body length, increased malformation rate, decreased hatching rate, advanced hatching time in response to low concentrations (50 and 100nmol/L) and delayed hatching time in response to high concentrations were observed after exposure, as were many other toxic effects, including pericardial edema and bent tails. The 72 hpf LC50 (median lethal concentration) was determined to be 624.364nmol/L. Treatment with certain concentrations of CuInS2/ZnS QDs significantly increased the superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels and significantly induced DNA damage. After treatment with CuInS2/ZnS QDs, the embryos showed highly up-regulated expression of Hsp70, Cyp1a and Wnt8a and significantly up-regulated expression of Mstn at 12 hpf. Overall, this study indicates that CuInS2/ZnS QDs are potentially toxic to G. rarus embryos. The information presented in this study will be helpful for fully understanding the toxicity induced by CuInS2/ZnS QDs in fish embryos.

Low-Intensity Pulsed Ultrasound Promotes Exercise-Induced Muscle Hypertrophy

The purpose of this study was to investigate whether low-intensity pulsed ultrasound (LIPUS) promotes exercise-induced muscle hypertrophy. Twenty-four adult Sprague-Dawley (SD) rats were randomly assigned to three groups (n = 8 per group): normal control group (NC), treadmill exercise group (TE) and treadmill exercise + LIPUS group (TE + LIPUS). The TE + LIPUS group received a LIPUS treatment (1 MHz, 30 mW/cm2) at the gastrocnemius for 20 min/d after treadmill exercise. The TE group was sham-treated. Eight weeks of treadmill training successfully established the exercise-induced muscle hypertrophy model. Muscle strength, muscle mass and muscle fiber cross-sectional area were significantly increased in the TE + LIPUS group compared with the TE group. Moreover, LIPUS treatment significantly upregulated the expression of Akt, mTOR, p-Akt and p-mTOR and significantly downregulated the expression of MSTN, ActRIIB, FoxO1 and its phosphorylation. The results indicated that LIPUS promotes exercise-induced muscle hypertrophy by facilitating protein synthesis and inhibiting the protein catabolism pathway.

Molecular Cloning, Identification, and Expression Patterns of Myostatin Gene in Water Buffalo (Bubalus Bubalis)

ABSTRACTMyostatin (MSTN), also named growth differentiation factor 8 (GDF8), is a transforming growth factor-β (TGF-β) family member with a key role in the negative regulation of skeletal muscle growth. However, its role in ovarian folliculogenesis remains unclear. To provide us with a basis for understanding this role, we cloned MSTN and examined its expression patterns in water buffalo (Bubalus bubalis). The complete ORF of the water buffalo MSTN gene is 1,128 nucleotides, which encode a 375 amino acid protein and sharing 99% identity at the deducted amino acid level with that of Bos taurus. Protein sequence analysis showed that MSTN is a weakly acerbic extracellular protein, consisting of signal peptides at 18-19 sites, a TGF-β propeptide, and a TGF-β domain. RT-PCR analyses demonstrated that water buffalo MSTN was expressed in multiple tissues but not limited to muscle. Immunohistochemistry staining confirmed the presence of MSTN in oocytes and granulosal cells. To our knowledge, this is the first study to confirm the expression of MSTN in the water buffalo ovary, suggesting an additional role of MSTN in water buffalo folliculogenesis, along with its role in skeletal muscle growth regulation. Further study of the regulatory mechanism of MSTN in water buffalo reproduction is warranted.Abbreviations: MSTN, myostatin; ORF, open reading frame.

Vitamin D induces myogenic differentiation in skeletal muscle derived stem cells.

Skeletal muscle wasting is a serious disorder associated with health conditions such as aging, chronic kidney disease and AIDS. Vitamin D is most widely recognized for its regulation of calcium and phosphate homeostasis in relation to bone development and maintenance. Recently, vitamin D supplementation has been shown to improve muscle performance and reduce the risk of falls in vitamin D deficient older adults. However, little is known of the underlying molecular mechanism(s) or the role it plays in myogenic differentiation. We examined the effect of 1,25-D3 on myogenic cell differentiation in skeletal muscle derived stem cells. Primary cultures of skeletal muscle satellite cells were isolated from the tibialis anterior, soleus and gastrocnemius muscles of 8-week-old C57/BL6 male mice and then treated with 1,25-D3. The efficiency of satellite cells isolation determined by PAX7+ cells was 81%, and they expressed VDR. Incubation of satellite cells with 1,25-D3 induces increased expression of: (i) MYOD, (ii) MYOG, (iii) MYC2, (iv) skeletal muscle fast troponin I and T, (v) MYH1, (vi) IGF1 and 2, (vii) FGF1 and 2, (viii) BMP4, (ix) MMP9 and (x) FST. It also promotes myotube formation and decreases the expression of MSTN. In conclusion, 1,25-D3 promoted a robust myogenic effect on satellite cells responsible for the regeneration of muscle after injury or muscle waste. This study provides a mechanistic justification for vitamin D supplementation in conditions characterized by loss of muscle mass and also in vitamin D deficient older adults with reduced muscle mass and strength, and increased risk of falls.

Expression of myostatin in postnatal mouse head and leg muscles

ObjectiveMyostatin (Mstn) is a member of the transforming growth factor‐β (TGF‐β) family that regulates muscle differentiation and growth. Thyroid hormone receptor alpha (TRα) effects to the producing the myogenic protein in muscle development. We aimed to identify the relationships between Mstn, TRα, and myosin heavy chain (MyHC) isoforms expression during postnatal mouse development.MethodsWe investigated the expression of Mstn, TRα, and MyHCs (embryonic, slow, IIa, IIb, and IIx) using quantitative real‐time RT‐PCR and ELISA (Mstn) in postnatal mouse muscles between day 0 and day 10. We also examined the correlations between Mstn, TR and MyHCs during early development of mouse masseter muscle (MM) and of the rectus femoris muscle (RFM).ResultsDistinct Mstn mRNA expression patterns were observed in the two muscles, despite nearly non‐significant changes in the Mstn protein abundance in MM. The expression pattern of the TRα mRNA in the MM differed from that observed in the RFM. The expression of the MyHC IIa, IIb and IIx mRNAs increased in the MM and decreased in the RFM from day 0 to day 10, while embryonic fiber MyHC mRNA expression was similar in both muscle types. Principal component analysis showed that the existence of correlation between; 1) TRα and MyHC, 2) Mstn and MyHC, and 3) TRα and Mstn. They were different according to two muscles. Cluster analyses identified the distinct clusters: cluster 1, days 0–4 for the MM and day 0 for the RFM; cluster 2, day 6 for the MM and day 2 for the RFM; and cluster 3, days 8–10 for the MM and days 4–10 for the RFM.ConclusionsThese data suggest that TRα potentially influences MyHC expression in both muscle types. In addition, Mstn has a limited effect in the MM related to the expression of individual MyHCs, as opposed to its role in the RFM, at early postnatal developmental stages. TRα could be involved in regulating both the temporal expression of MyHCs and Mstn at early postnatal stages in the mouse head and leg muscles.Support or Funding Informationnone

CDNA sequence and protein bioinformatics analyses of MSTN in African catfish (Clarias gariepinus).

Myostatin, also known as growth differentiation factor 8, has been identified as a potent negative regulator of skeletal muscle growth. The purpose of this study was to characterize and predict function of the myostatin gene of the African catfish (Cg-MSTN). Expression of Cg-MSTN was determined at three growth stages to establish the relationship between the levels of MSTN transcript and skeletal muscle growth. The partial cDNA sequence of Cg-MSTN was cloned by using published information from its congener walking catfish (Cm-MSTN). The Cg-MSTN was 1194bp in length encoding a protein of 397 amino acids. The deduced MSTN sequence exhibited key functional sites similar to those of other members of the TGF-β superfamily, especially, the proteolytic processing site (RXXR motif) and nine conserved cysteines at the C-terminal. Expression of MSTN appeared to be correlated with muscle development and growth of African catfish. Protein bioinformatics revealed that the primary sequence of Cg-MSTN shared 98% sequence identity with that of walking catfish Cm-MSTN with only two different residues, [Formula: see text]. and [Formula: see text]. The proposed model of Cg-MSTN revealed the key point mutation [Formula: see text] causing a 7.35Å shorter distance between the N- and C-lobes and an approximately 11° narrow angle than those of Cm-MSTN. The substitution of a proline residue near the proteolytic processing site which altered the structure of myostatin may play a critical role in reducing proteolytic activity of this protein in African catfish.

Myostatin and IGF-I signaling in end-stage human heart failure: a qRT-PCR study.

BackgroundMyostatin (Mstn) is a key regulator of heart metabolism and cardiomyocyte growth interacting tightly with insulin-like growth factor I (IGF-I) under physiological conditions. The pathological role of Mstn has also been suggested since Mstn protein was shown to be upregulated in the myocardium of end-stage heart failure. However, no data are available about the regulation of gene expression of Mstn and IGF-I in different regions of healthy or pathologic human hearts, although they both might play a crucial role in the pathomechanism of heart failure.MethodsIn the present study, heart samples were collected from left ventricles, septum and right ventricles of control healthy individuals as well as from failing hearts of dilated (DCM) or ischemic cardiomyopathic (ICM) patients. A comprehensive qRT-PCR analysis of Mstn and IGF-I signaling was carried out by measuring expression of Mstn, its receptor Activin receptor IIB (ActRIIB), IGF-I, IGF-I receptor (IGF-IR), and the negative regulator of Mstn miR-208, respectively. Moreover, we combined the measured transcript levels and created complex parameters characterizing either Mstn- or IGF-I signaling in the different regions of healthy or failing hearts.ResultsWe have found that in healthy control hearts, the ratio of Mstn/IGF-I signaling was significantly higher in the left ventricle/septum than in the right ventricle. Moreover, Mstn transcript levels were significantly upregulated in all heart regions of DCM but not ICM patients. However, the ratio of Mstn/IGF-I signaling remained increased in the left ventricle/septum compared to the right ventricle of DCM patients (similarly to the healthy hearts). In contrast, in ICM hearts significant transcript changes were detected mainly in IGF-I signaling. In paralell with these results miR-208 showed mild upregulation in the left ventricle of both DCM and ICM hearts.ConclusionsThis is the first demonstration of a spatial asymmetry in the expression pattern of Mstn/IGF-I in healthy hearts, which is likely to play a role in the different growth regulation of left vs. right ventricle. Moreover, we identified Mstn as a massively regulated gene in DCM but not in ICM as part of possible compensatory mechanisms in the failing heart.