Effects of Nitric Oxide on C2C12 Cell Inflammatory Responses and Notexin-Induced Muscle Injury

Skeletal muscle injury is an acute inflammatory condition caused by an inflammatory response. To reduce inflammatory cell infiltration and relieve skeletal muscle injury, efficient treatment is urgently needed. Nitric oxide is a free radical molecule reported to have anti-inflammatory effects. In this study, we showed that NO could inhibit the inflammatory response of C2C12 cells in vitro and protect rat skeletal muscle injury from notexin in vivo. NO synthase inhibitor (L-NG-Nitroarginine Methyl Este, L-NAME) and NO donor (sodium nitroprusside dehydrate, SNP) were used to explore the vital role of lipopolysaccharides (LPSs) in LPS-stimulated C2C12 myoblasts.The expression of IL-18 and IL-1 beta was upregulated by L-NAME and downregulated by SNP, as indicated by the ELISA results. NO can reduce ASC, Caspase-1, and NLRP3 mRNA and protein levels. Furthermore, NO was detected in the rat model. The results of immunohistochemical staining showed that the production of DMD decreased. We conducted qRT-PCR and western blotting to detect the expression of Jo-1, Mi-2, TLR2, and TLR4 on day 6 post injury following treatment with L-NAME and SNP. The expression of Jo-1, Mi-2, TLR2, and TLR4 was upregulated by L-NAME and significantly reversed by SNP. NO can alleviate C2C12 cell inflammatory responses and protect rat skeletal muscle injury from notexin.