Molecular and cellular effects of gold nanoparticles treatment in experimental diabetic myopathy.

Background This study aims to address the effects of gold nanoparticles (AuNPs) on diabetic myopathy in streptozotocin (STZ)-induced diabetic rats. Materials and methods Adult male rats were separated into three groups (n = 15): non-diabetic control (ND), diabetic (D), and diabetic treated with AuNPs (2.5 mg/kg, D + AuNPs) intraperitoneally for 4 weeks. A single injection of 50 mg/kg STZ was used to induce diabetes. Results Treatment with AuNPs lowered blood glucose levels. Skeletal muscle mRNA expression of two muscle-specific E3 ubiquitin-ligases enzymes, F-box-only protein 32 (FBXO32) and muscle RING-finger protein-1 (MuRF1) were upregulated in the D group. Diabetic rats showed significant increases in the skeletal muscle expression levels of plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor-α (TNF-α), transforming growth factor-β1 (TGF-β1), and a decrease in glucose transporter 4 (GLUT4) expression. Superoxide dismutase (SOD) activity decreased and malondialdehyde (MDA) level increased in skeletal muscles of D group. Compared to the D group, expression levels of FBXO32, MuRF1, PAI-1 TNF-α, and TGF-β1 were decreased in the D + AuNPs group, and mRNA of GLUT4 increased. Furthermore, in D + AuNPs group, skeletal muscle MDA levels decreased while SOD activity increased. Conclusion In experimental models, AuNPs can ameliorate muscle atrophy by reducing hyperglycemia, inflammation, and oxidative stress, and by suppressing the ubiquitin-proteasome proteolytic process