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Redox Biology Jul 2024Cysteine, the rate-controlling amino acid in cellular glutathione synthesis is imported as cystine, by the cystine/glutamate antiporter, xCT, and subsequently reduced to...
Cysteine, the rate-controlling amino acid in cellular glutathione synthesis is imported as cystine, by the cystine/glutamate antiporter, xCT, and subsequently reduced to cysteine. As glutathione redox is important in muscle regeneration in aging, we hypothesized that xCT exerts upstream control over skeletal muscle glutathione redox, metabolism and regeneration. Bioinformatic analyses of publicly available datasets revealed that expression levels of xCT and GSH-related genes are inversely correlated with myogenic differentiation genes. Muscle satellite cells (MuSCs) isolated from Slc7a11 mice, which harbour a mutation in the Slc7a11 gene encoding xCT, required media supplementation with 2-mercaptoethanol to support cell proliferation but not myotube differentiation, despite persistently lower GSH. Slc7a11 primary myotubes were larger compared to WT myotubes, and also exhibited higher glucose uptake and cellular oxidative capacities. Immunostaining of myogenic markers (Pax7, MyoD, and myogenin) in cardiotoxin-damaged tibialis anterior muscle fibres revealed greater MuSC activation and commitment to differentiation in Slc7a11 muscle compared to WT mice, culminating in larger myofiber cross-sectional areas at 21 days post-injury. Slc7a11 mice subjected to a 5-week exercise training protocol demonstrated enhanced insulin tolerance compared to WT mice, but blunted muscle mitochondrial biogenesis and respiration in response to exercise training. Our results demonstrate that the absence of xCT inhibits cell proliferation but promotes myotube differentiation by regulating cellular metabolism and glutathione redox. Altogether, these results support the notion that myogenesis is a redox-regulated process and may help inform novel therapeutic approaches for muscle wasting and dysfunction in aging and disease.
Topics: Animals; Mice; Oxidation-Reduction; Cell Differentiation; Glutathione; Muscle, Skeletal; Amino Acid Transport System y+; Energy Metabolism; Muscle Development; Satellite Cells, Skeletal Muscle; Muscle Fibers, Skeletal; Cystine
PubMed: 38815331
DOI: 10.1016/j.redox.2024.103213 -
PLoS Neglected Tropical Diseases May 2024Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are...
BACKGROUND
Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are not yet fully understood. Herein, the effectiveness of photobiomodulation effects on regenerative response of C2C12 myoblast cells following exposure to Bothrops jararacussu venom (BjsuV), as well as the mechanisms involved was investigated.
METHODOLOGY/PRINCIPAL FINDINGS
C2C12 myoblast cells were exposed to BjsuV (12.5 μg/mL) and irradiated once for 10 seconds with laser light of 660 nm (14.08 mW; 0.04 cm2; 352 mW/cm2) or 780 nm (17.6 mW; 0.04 cm2; 440 mW/ cm2) to provide energy densities of 3.52 and 4.4 J/cm2, and total energies of 0.1408 and 0.176 J, respectively. Cell migration was assessed through a wound-healing assay. The expression of MAPK p38-α, NF-Кβ, Myf5, Pax-7, MyoD, and myogenin proteins were assessed by western blotting analysis. In addition, interleukin IL1-β, IL-6, TNF-alfa and IL-10 levels were measured in the supernatant by ELISA. The PBM applied to C2C12 cells exposed to BjsuV promoted cell migration, increase the expression of myogenic factors (Pax7, MyF5, MyoD and myogenin), reduced the levels of proinflammatory cytokines, IL1-β, IL-6, TNF-alfa, and increased the levels of anti-inflammatory cytokine IL-10. In addition, PBM downregulates the expression of NF-kB, and had no effect on p38 MAKP.
CONCLUSION/SIGNIFICANCE
These data demonstrated that protection of the muscle cell by PBM seems to be related to the increase of myogenic factors as well as the modulation of inflammatory mediators. PBM therapy may offer a new therapeutic strategy to address the local effects of snakebite envenoming by promoting muscle regeneration and reducing the inflammatory process.
Topics: Animals; Bothrops; Myoblasts; Mice; Low-Level Light Therapy; Cytokines; Cell Line; Crotalid Venoms; Myogenin; PAX7 Transcription Factor; NF-kappa B; MyoD Protein; Cell Movement; Myogenic Regulatory Factor 5; p38 Mitogen-Activated Protein Kinases; Snake Bites; Venomous Snakes
PubMed: 38814992
DOI: 10.1371/journal.pntd.0012227 -
Food & Function Jul 2024Yak-Kong (YK) is a small black soybean widely cultivated in Korea. It is considered to have excellent health functionality, as it has been reported to have better...
Yak-Kong (YK) is a small black soybean widely cultivated in Korea. It is considered to have excellent health functionality, as it has been reported to have better antioxidant efficacy than conventional black or yellow soybeans. Since YK has been described as good for the muscle health of the elderly in old oriental medicine books, this study sought to investigate the effect of fermented YK with subsp. LDTM 8102 (FYK) on muscle atrophy. In C2C12 mouse myoblasts, FYK elevated the expression of MyoD, total MHC, phosphorylated AKT, and PGC1α. In addition, two kinds of studies were conducted using both an induced and normal aging mouse model. The behavioral test results showed that in the induced aging mouse model, FYK intake alleviated age-related muscle weakness and loss of exercise performance. In addition, FYK alleviated muscle mass decrease and improved the expression of biomarkers including total MHC, myf6, phosphorylated AKT, PGC1α, and Tfam, which are related to myoblast differentiation, muscle protein synthesis, and mitochondrial generation in the muscle. In the normal aging model, FYK consumption did not increase muscle mass, but did upregulate the expression levels of biomarkers related to myoblast differentiation, muscle hypertrophy, and muscle function. Furthermore, it mitigated age-related declines in skeletal muscle force production and functional limitation by enhancing exercise performance and grip strength. Taken together, the results suggest that FYK has the potential to be a new functional food material that can alleviate the loss of muscle mass and strength caused by aging and prevent sarcopenia.
Topics: Animals; Mice; Muscular Atrophy; Aging; Male; Bifidobacterium animalis; Fermentation; Disease Models, Animal; Republic of Korea; Muscle, Skeletal; Probiotics; Intestines; Soy Foods; Humans; Myoblasts; Glycine max; Mice, Inbred C57BL
PubMed: 38812412
DOI: 10.1039/d3fo04204a -
Journal of Agricultural and Food... May 2024Cultured meat technology is expected to solve problems such as resource shortages and environmental pollution, but the muscle fiber differentiation efficiency of...
Cultured meat technology is expected to solve problems such as resource shortages and environmental pollution, but the muscle fiber differentiation efficiency of cultured meat is low. Genipin is the active compound derived from Ellis, which has a variety of activities. Additionally, genipin serves as a noncytotoxic agent for cross-linking, which is suitable as a foundational scaffold for tissue regeneration. However, the impact of genipin on myoblast differentiation remains to be studied. The research revealed that genipin was found to improve the differentiation efficiency of myoblasts. Genipin improved mitochondrial membrane potential by activating the AMPK signaling pathway of myoblasts, promoting mitochondrial biogenesis, and mitochondrial network remodeling. Genipin activated autophagy in myoblasts and maintained cellular homeostasis. Autophagy inhibitors blocked the pro-differentiation effect of genipin. These results showed that genipin improved the differentiation efficiency of myoblasts, which provided a theoretical basis for the development of cultured meat technology.
PubMed: 38807430
DOI: 10.1021/acs.jafc.3c06638 -
Journal of Biomedical Research May 2024Macrophages mediated inflammatory response is crucial for the recovery of skeletal muscle following ischemia. Thus, it's necessary to exploit macrophages based...
Macrophages mediated inflammatory response is crucial for the recovery of skeletal muscle following ischemia. Thus, it's necessary to exploit macrophages based therapeutic targets for ischemic disease. Here, we found mRNA level of SR-A1 was elevated in patients with critical limb ischemia by analysis of gene expression omnibus (GEO) database. Then we investigated the role and the underlined mechanisms of macrophage SR-A1 in a mouse HLI model. Compared with the SR-A1 mice, the Lyz /SR-A1 (SR-A1 ) mice showed significantly lower laser doppler blood flow in the ischemic limb at day 7 after HLI. Consistently, histological analysis exhibited that ischemic limb of SR-A1 mice displayed more sever and sustained necrotic morphology, inflammation and fibrosis, decreased vessel density and regeneration rate, compared with which of control SR-A1 mice. Furthermore, restoration of wild-type myeloid cells to SR-A1 knock-out mice effectively relieved the doppler perfusion in the ischemic limb and restrained skeletal muscle damage 7 days post HLI. In line with findings, when co-cultivating macrophages with the mouse myoblast line C2C12, SR-A1 bone marrow macrophage significantly inhibited myoblast differentiation . Mechanically, SR-A1 enhanced skeletal muscle regeneration response to HLI by inhibiting the oncostatin M (OSM) production via suppressed NF-κB signaling activation. These results indicates that SR-A1 is a promising candidate molecule to improve tissue repair and regeneration in peripheral ischemic arterial disease.
PubMed: 38807379
DOI: 10.7555/JBR.38.20240117 -
Proceedings of the National Academy of... Jun 2024Myogenesis is a multistep process that requires a spatiotemporal regulation of cell events resulting finally in myoblast fusion into multinucleated myotubes. Most major...
Myogenesis is a multistep process that requires a spatiotemporal regulation of cell events resulting finally in myoblast fusion into multinucleated myotubes. Most major insights into the mechanisms underlying fusion seem to be conserved from insects to mammals and include the formation of podosome-like protrusions (PLPs) that exert a driving force toward the founder cell. However, the machinery that governs this process remains poorly understood. In this study, we demonstrate that MTM1 is the main enzyme responsible for the production of phosphatidylinositol 5-phosphate, which in turn fuels PI5P 4-kinase α to produce a minor and functional pool of phosphatidylinositol 4,5-bisphosphate that concentrates in PLPs containing the scaffolding protein Tks5, Dynamin-2, and the fusogenic protein Myomaker. Collectively, our data reveal a functional crosstalk between a PI-phosphatase and a PI-kinase in the regulation of PLP formation.
Topics: Animals; Phosphatidylinositol Phosphates; Mice; Cell Fusion; Myoblasts; Podosomes; Protein Tyrosine Phosphatases, Non-Receptor; Muscle Development
PubMed: 38805272
DOI: 10.1073/pnas.2217971121 -
Clinical Science (London, England :... Jun 2024Myopenia is a condition marked by progressive decline of muscle mass and strength and is associated with aging or obesity. It poses the risk of falling, with potential...
Myopenia is a condition marked by progressive decline of muscle mass and strength and is associated with aging or obesity. It poses the risk of falling, with potential bone fractures, thereby also increasing the burden on family and society. Skeletal muscle wasting is characterized by a reduced number of myoblasts, impaired muscle regeneration and increased muscle atrophy markers (Atrogin-1, MuRF-1). Endothelin-1 (ET-1) is a potent vasoconstrictor peptide. Increased circulating levels of ET-1 is noted with aging and is associated with muscular fibrosis and decline of strength. However, the regulatory mechanism controlling its effect on myogenesis and atrophy remains unknown. In the present study, the effects of ET-1 on myoblast proliferation, differentiation and development were investigated in C2C12 cells and in ET-1-infused mice. The results show that ET-1, acting via ETB receptors, reduced insulin-stimulated cell proliferation, and also reduced MyoD, MyoG and MyHC expression in the differentiation processes of C2C12 myoblasts. ET-1 inhibited myoblast differentiation through ETB receptors and the p38 mitogen-activated protein kinase (MAPK)-dependent pathway. Additionally, ET-1 decreased MyHC expression in differentiated myotubes. Inhibition of proteasome activity by MG132 ameliorated the ET-1-stimulated protein degradation in differentiated C2C12 myotubes. Furthermore, chronic ET-1 infusion caused skeletal muscle atrophy and impaired exercise performance in mice. In conclusion, ET-1 inhibits insulin-induced cell proliferation, impairs myogenesis and induces muscle atrophy via ETB receptors and the p38 MAPK-dependent pathway.
Topics: Animals; Muscle Development; p38 Mitogen-Activated Protein Kinases; Endothelin-1; Muscle, Skeletal; Cell Proliferation; Cell Differentiation; Cell Line; Mice; Male; Mice, Inbred C57BL; Myoblasts; Signal Transduction; MAP Kinase Signaling System; Muscular Atrophy
PubMed: 38804865
DOI: 10.1042/CS20240341 -
Biotech (Basel (Switzerland)) Apr 2024A myogenetic oligodeoxynucleotide (myoDN), iSN04 (5'-AGA TTA GGG TGA GGG TGA-3'), is a single-stranded 18-base telomeric DNA that serves as an anti-nucleolin aptamer and...
A myogenetic oligodeoxynucleotide (myoDN), iSN04 (5'-AGA TTA GGG TGA GGG TGA-3'), is a single-stranded 18-base telomeric DNA that serves as an anti-nucleolin aptamer and induces myogenic differentiation, which is expected to be a nucleic acid drug for the prevention of disease-associated muscle wasting. To improve the drug efficacy and synthesis cost of myoDN, shortening the sequence while maintaining its structure-based function is a major challenge. Here, we report the novel 12-base non-telomeric myoDN, iMyo01 (5'-TTG GGT GGG GAA-3'), which has comparable myogenic activity to iSN04. iMyo01 as well as iSN04 promoted myotube formation of primary-cultured human myoblasts with upregulation of myogenic gene expression. Both iMyo01 and iSN04 interacted with nucleolin, but iMyo01 did not bind to berberine, the isoquinoline alkaloid that stabilizes iSN04. Nuclear magnetic resonance revealed that iMyo01 forms a G-quadruplex structure despite its short sequence. Native polyacrylamide gel electrophoresis and a computational molecular dynamics simulation indicated that iMyo01 forms a homodimer to generate a G-quadruplex. These results provide new insights into the aptamer truncation technology that preserves aptamer conformation and bioactivity for the development of efficient nucleic acid drugs.
PubMed: 38804293
DOI: 10.3390/biotech13020011 -
Scientific Reports May 2024Telocytes are a unique interstitial cell type that functions in adulthood and embryogenesis. They have characteristic immunohistochemical phenotypes while acquiring...
Telocytes are a unique interstitial cell type that functions in adulthood and embryogenesis. They have characteristic immunohistochemical phenotypes while acquiring different immunohistochemical properties related to the organ microenvironment. The present study aims to investigate the immunohistochemical features of embryonic telocytes during myogenesis and describe their morphology using light microscopy and TEM. Telocytes represent a major cellular constituent in the interstitial elements. They had distinguished telopodes and podoms and formed a 3D interstitial network in the developing muscles. They formed heterocellular contact with myoblasts and nascent myotubes. Telocytes also had distinctive secretory activity. Telocytes identified by CD34. They also express CD68 and MMP-9 to facilitate the development of new tissues. Expression of CD21 by telocytes may reveal their function in immune defense. They also express VEGF, which regulates angiogenesis. In conclusion, the distribution and immunological properties of telocytes in the myogenic tissue indicate that telocytes provide biological and structural support in the development of the myogenic tissue architecture and organization.
Topics: Telocytes; Animals; Muscle Development; Immunohistochemistry; Mice; Antigens, CD; Antigens, CD34; Cellular Microenvironment; Matrix Metalloproteinase 9; Antigens, Differentiation, Myelomonocytic; Vascular Endothelial Growth Factor A; Myoblasts
PubMed: 38802438
DOI: 10.1038/s41598-024-62103-1 -
Journal of Diabetes Research 2024Islet transplantation (ITx) is an established and safe alternative to pancreas transplantation for type 1 diabetes mellitus (T1DM) patients. However, most ITx recipients...
Islet transplantation (ITx) is an established and safe alternative to pancreas transplantation for type 1 diabetes mellitus (T1DM) patients. However, most ITx recipients lose insulin independence by 3 years after ITx due to early graft loss, such that multiple donors are required to achieve insulin independence. In the present study, we investigated whether skeletal myoblast cells could be beneficial for promoting angiogenesis and maintaining the differentiated phenotypes of islets. In vitro experiments showed that the myoblast cells secreted angiogenesis-related cytokines (vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and stromal-derived factor-1 (SDF-1)), contributed to maintenance of differentiated islet phenotypes, and enhanced islet cell insulin secretion capacity. To verify these findings in vivo, we transplanted islets alone or with myoblast cells under the kidney capsule of streptozotocin-induced diabetic mice. Compared with islets alone, the group bearing islets with myoblast cells had a significantly lower average blood glucose level. Histological examination revealed that transplants with islets plus myoblast cells were associated with a significantly larger insulin-positive area and significantly higher number of CD31-positive microvessels compared to islets alone. Furthermore, islets cotransplanted with myoblast cells showed JAK-STAT signaling activation. Our results suggest two possible mechanisms underlying enhancement of islet graft function with myoblast cells cotransplantation: "indirect effects" mediated by angiogenesis and "direct effects" of myoblast cells on islets via the JAK-STAT cascade. Overall, these findings suggest that skeletal myoblast cells enhance the function of transplanted islets, implying clinical potential for a novel ITx procedure involving myoblast cells for patients with diabetes.
Topics: Animals; Islets of Langerhans Transplantation; Diabetes Mellitus, Experimental; Myoblasts, Skeletal; Mice; Male; Insulin; Neovascularization, Physiologic; Hepatocyte Growth Factor; Mice, Inbred C57BL; Vascular Endothelial Growth Factor A; Islets of Langerhans; Chemokine CXCL12; Blood Glucose; Diabetes Mellitus, Type 1; Signal Transduction; Insulin Secretion; Cell Differentiation
PubMed: 38800586
DOI: 10.1155/2024/5574968