The risk for developing insulin resistance and type II diabetes increases with age. Although lifestyle factors contribute to age-related insulin resistance, aging itself independently reduces insulin sensitivity, partially via an increase in inflammation and cellular senescence. Low-frequency ultrasound (LFU) has been shown to rejuvenate senescent cells and to reduce the proinflammatory senescence associated secretory phenotype. Because diabetes is more common in aged individuals, there is an increased need to develop effective therapeutics for aged individuals with this condition. This study investigated the effects of LFU treatment on muscle function, blood glucose control, and skeletal muscle gene expression in aged, insulin-resistant, and diabetic mice. Insulin resistance was induced via high-fat, high-sucrose (HFHS) diet, and diabetes was induced via HFHS diet plus a low dose of streptozotocin. Insulin resistant and diabetic mice exhibited impaired glucose metabolism and physical function, as well as an altered transcriptomic profile in skeletal muscle, indicating an increase in inflammation and an immune response. LFU treatment reversed much of the transcriptomic changes that occurred with insulin resistance and diabetes but had no effect on blood glucose control or physical function. LFU demonstrates potential as a non-invasive therapy for reducing inflammation and altering immune cell function in skeletal muscle in insulin resistant and diabetic populations.
Keywords: Aging; RNAseq; diabetes; insulin resistance; low-frequency ultrasound; mitochondria; senescence; skeletal muscle.