Therapeutic effect of psoralen on muscle atrophy induced by tumor necrosis factor-α

Objective(s): To observe and determine the effect and mechanism of psoralen on tumor necrosis factor-alpha (TNF-alpha)-induced muscle atrophy. Materials and Methods: Three sets of C2C12 cells, including blank control, TNF-alpha (10 or 20 ng/ml) treatment and a TNF-alpha (10 or 20 ng/ml) plus psoralen (80 mu M) administration were investigated. Cell viability was assessed using Cell Counting Kit-8 (CCK-8) assay. Western blot analysis was used to detect protein expression of atrophic markers. Flowcytometry was used to observe the effect of psoralen on apoptosis. A quantitative real-time PCR (qRT-PCR) assay was performed to detect the mRNA level of miR-675-5P. Results: TNF-alpha (1, 10, 20 and 100 ng/ml) treatment inhibited C2C12 myoblast viability (P<0.001), while 24 hr of psoralen administration increased the viability, and lowered TNF-alpha cytotoxicity (P<0.001). MURF1, MAFbx, TRIM62 and GDF15 expressions were significantly increased in TNF-alpha (10 ng/ml or 20 ng/ml)-treated group (P<0.001), and psoralen could significantly decrease the expression of these proteins (P<0.001). Apoptotic rate of C2C12 myoblasts was increased after TNF-alpha (10 ng/ml and 20 ng/ml) treatment, and was significantly decreased after psoralen treatment (P<0.001). miR-675-5P was increased in TNF-alpha-treated C2C12 myoblasts compared to control group, and it was significantly decreased after psoralen treatment. Conclusion: Psoralen could reduce TNF-alpha-induced cytotoxicity, atrophy and apoptosis in C2C12 myoblasts. The therapeutic effect of psoralen may be achieved by down-regulating miR-675-5P.