Alpha-linolenic acid is an important polyunsaturated fatty acid that exhibits anticancer, anti-inflammatory, and antioxidative effects. In this study, we investigated the protective effects of alpha-linolenic acid on the cell proliferation and differentiation of C2C12 cells under essential amino acid-deficient conditions. Different concentrations of alpha-linolenic acid and essential amino acids were added to the growth and differentiation media. The concentrations of 10 μM of alphalinolenic acid and 2% essential amino acid were chosen for subsequent experiments. Supplementation with alpha-linolenic acid and essential amino acids improved the proliferation and differentiation of C2C12 cells and significantly increased the mRNA levels of catalase, superoxide dismutase, B-cell lymphoma-2, and beclin-1 as well as the protein levels of PPARγ coactivator-1α compared to those in the controls. Moreover, supplementation with alpha-linolenic acid and essential amino acids reduced the levels of phosphorylated H2A.X variant histone, Bcl-2-associated X, p53, and light chain 3 during C2C12 cell proliferation, and increased the expression levels of myogenic factors 4 (myogenin) and 5 during C2C12 cell differentiation. Overall, we determined that alpha-linolenic acid and essential amino acids maintained the cell proliferation and differentiation of C2C12 cells via their anti-oxidative, anti-apoptotic, and anti-autophagic effects.
Nitric oxide (NO)-induced protein S-nitrosylation triggers mitochondrial dysfunction and was related to cell senescence. However, the exact mechanism of these damages is not clear. In the present study, to investigate the relationship between in vitro aging and NO-induced protein S-nitrosylation, oocytes were treated with sodium nitroprusside dihydrate (SNP), and the resultant S-nitrosylated proteins were detected through biotin-switch assay. The results showed that levels of protein S-nitroso thiols (SNO)s and expression of S-nitrosoglutathione reductase (GSNOR) increased, while activity and function of mitochondria were impaired during oocyte aging. Addition of SNP, a NO donor, to the oocyte culture led to accelerated oocyte aging, increased mitochondrial dysfunction and damage, apoptosis, ATP deficiency, and enhanced ROS production. These results suggested that the increased NO signal during oocyte aging in vitro, accelerated oocyte degradation due to increased protein S-nitrosylation, and ROS-related redox signaling.
Cell adhesion plays an important role in the differentiation of the morphogenesis and the trophectoderm epithelium of the blastocyst. In the porcine embryo, CDH1 mediated adhesion initiates at compaction before blastocyst formation, regulated post-translationally via protein kinase C and other signaling molecules. Here we focus on muscle RAS oncogene homolog (M-RAS), which is the closest relative to the RAS related proteins and shares most regulatory and effector interactions. To characterize the effects of M-RAS on embryo compaction, we used gain- and loss-of-function strategies in porcine embryos, in which M-RAS gene structure and protein sequence are conserved. We showed that knockdown of M-RAS in zygotes reduced embryo development abilities and CDH1 expression. Moreover, the phosphorylation of ERK was also decreased in M-RAS KD embryos. Overexpression of M-RAS allows M-RAS KD embryos to rescue the embryo compaction and blastocyst formation. Collectively, these results highlight novel conserved and multiple effects of M-RAS during porcine embryo development.