[Skeletal muscle-specific knockdown of ACSL1 gene ameliorates cisplatin-induced skeletal muscle atrophy]

The aim of this study was to explore the role of long-chain acyl-CoA synthetase 1 (ACSL1) in cisplatin-induced skeletal muscle atrophy and the underlying mechanism. Wild-type mice were divided into cisplatin group and control group. The results of fluorescence quantitative PCR and sequencing of reference transcriptome showed that ACSL1 gene was significantly up-regulated in the skeletal muscle of cisplatin group compared with the control group, suggesting that ACSL1 may play a key role in cisplatin-induced skeletal muscle atrophy. To further investigate ACSL1's function and potential mechanism, the present study constructed an adeno-associated virus to achieve muscle-specific ACSL1 knockdown and established a cisplatin-induced skeletal muscle atrophy model. The results of immunofluorescence staining showed that compared with mice only receiving cisplatin intervention, mice receiving ACSL1 gene knockdown and cisplatin intervention had significantly increased muscle fiber cross-sectional area, maximum diameter, minimum diameter, and average diameter in their skeletal muscles. The results of RT-qPCR and immunohistochemical staining showed that knockdown of the ACSL1 gene in skeletal muscle down-regulated the mRNA expression levels of atrophy related gene 1 (Atrogin-1) and autophagy-related factors such as autophagy related protein 16 like protein 1 (Atg16L1), Atg12, and Atg7 in cisplatin-induced skeletal muscle atrophy, up-regulated the protein expression level of myogenin, and down-regulated Toll-like receptor 4 (TLR4) protein expression level, but had no significant effect on the mRNA expression levels of ferroptosis-related factors (except for cyclooxygenase-2) and inflammation-related factors such as stimulator of interferon genes (STING), Toll-like receptor 4 (TLR4) and TLR9 in cisplatin-induced skeletal muscle atrophy. These results suggest that specific knockdown of ACSL1 gene in skeletal muscle may alleviate cisplatin-induced skeletal muscle atrophy by down-regulating the expression of Atrogin-1, TLR4 and autophagy-related factors.