Effects of acupuncture on the miR-146a-mediated IRAK1/TRAF6/NF-κB signaling pathway in rats with sarcopenia induced by D-galactose.

Abstract

Sarcopenia during aging is closely linked to sterile, low-grade, chronic inflammation. However, considering the increasingly aging global population, the effectiveness of existing treatments for sarcopenia is not exact, and acupuncture, as an effective anti-inflammatory therapy, has the potential to treat it. Fifty Sprague-Dawley rats were randomly allocated into five groups, including Control group, D-galactose (D-gal) group, D-gal + acupuncture (DA) group, D-gal + non-acupoint (DN) group and D-gal amino acid mixture (DAA) group. An aging rat was model constructed using D-gal for 12 weeks. Rats in the control group received 0.9% physiological saline daily. Treatment groups were acupunctured or given amino acid mixture interventions daily, and lasted for last 4 consecutive weeks. The effects of acupuncture were evaluated by the hematoxylin and eosin staining (H&E), transmission electron microscopic (TEM) examination and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. The anti-inflammatory mechanism of acupuncture was studied by using the expressions of microRNA-146a (miR-146a) mediated nuclear factor-kappa B (NF-κB) signaling pathway-related proteins were detected by immunofluorescence, western blotting, quantitative real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Rats injected by D-galactose (D-gal) revealed apparent skeletal muscle atrophy with significantly reduced cross-sectional area and fiber diameter. In contrast, acupuncture treatment alleviated these hallmarks of skeletal muscle atrophy and mitigated the mitochondrial aberrations and skeletal muscle apoptosis in D-gal rats. In addition, acupuncture also downgraded the overexpression of inflammatory factors in skeletal muscle, influenced miR-146a and the target genes level, and inhibited NF-κB nuclear translation in D-gal rats. Acupuncture may ameliorate skeletal muscle atrophy, and its effects may be associated with the control of mitochondrial function regulation and the suppression of inflammation.