Skeletal muscle mitochondrial remodeling in heart failure: An update on mechanisms and therapeutic opportunities.

Patients with heart failure (HF) usually present with skeletal muscle diseases of varying severity, ranging from early fatigue on exercise to sarcopenia, sarcopenic obesity or cachexia, and frailty, which are significant predictors of HF prognosis. Abnormal mitochondrial metabolism has been identified as one of the earliest signs of skeletal muscle injury in HF and is associated with pathological alterations in muscle, manifested as muscle wasting, myocyte atrophy and apoptosis, fiber type shift, impaired contractile coupling, and muscle fat infiltration. In this review, we update the evidence for skeletal muscle mitochondrial remodeling in HF patients or animal models, including the impairments in mitochondrial ultrastructure, oxidative metabolism, electron transport chain (ETC), phosphorylation apparatus, phosphotransfer system, and quality control. We also focus on molecular regulatory mechanisms upstream of mitochondria, including circulating factors (e.g., RAAS, TNF-α IL-6, IGF-1, GH, ghrelin, adiponectin, NO) and molecular signals within myocytes (e.g., PGC-1α, PPARs, AMPK, SIRT1/3, ROS, and MuRF1). Besides the therapies targeting the signaling pathways mentioned above, such as AdipoRon and elamipretide, we further summarize other potential pharmacological approaches like inhibitors of sodium-glucose cotransporter 2 (SGLT2) and dipeptidyl peptidase-4 (DPP-4), as well as some natural products, which may have the beneficial effects on improving the skeletal muscle mitochondrial function of HF. Targeting myocyte mitochondrial biogenesis, oxidative metabolism, oxidative phosphorylation, and reduction of oxidative stress injury are promising future opportunities for the prevention and management of skeletal muscle myopathy in HF.