Objectives: To observe and determine the effect and mechanism of psoralen on tumor necrosis factor-α (TNF-α)-induced muscle atrophy.
Materials and methods: Three sets of C2C12 cells, including blank control, TNF-α (10 or 20 ng/ml) treatment and a TNF-α (10 or 20 ng/ml) plus psoralen (80 μM) 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-α (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-α cytotoxicity (P<0.001). MURF1, MAFbx, TRIM62 and GDF15 expressions were significantly increased in TNF-α (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-α (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-α-treated C2C12 myoblasts compared to control group, and it was significantly decreased after psoralen treatment.
Conclusion: Psoralen could reduce TNF-α-induced cytotoxicity, atrophy and apoptosis in C2C12 myoblasts. The therapeutic effect of psoralen may be achieved by down-regulating miR-675-5P.
Keywords: C2C12; Muscle atrophy; Psoralen; Tumor necrosis factor α; miR-675-5P.