Loss of Myostatin Alters Mitochondrial Oxidative Phosphorylation, TCA Cycle Activity, and ATP Production in Skeletal Muscle

Abstract

Myostatin (MSTN) is an important negative regulator of skeletal muscle growth in animals. A lack of MSTN promotes lipolysis and glucose metabolism but inhibits oxidative phosphorylation (OXPHOS). Here, we aimed to investigate the possible mechanism of MSTN regulating the mitochondrial energy homeostasis of skeletal muscle. To this end, MSTN knockout mice were generated by the CRISPR/Cas9 technique. Expectedly, the MSTN null (Mstn−/−) mouse has a hypermuscular phenotype. The muscle metabolism of the Mstn−/− mice was detected by an enzyme-linked immunosorbent assay, indirect calorimetry, ChIP-qPCR, and RT-qPCR. The resting metabolic rate and body temperature of the Mstn−/− mice were significantly reduced. The loss of MSTN not only significantly inhibited the production of ATP by OXPHOS and decreased the activity of respiratory chain complexes, but also inhibited key rate-limiting enzymes related to the TCA cycle and significantly reduced the ratio of NADH/NAD+ in the Mstn−/− mice, which then greatly reduced the total amount of ATP. Further ChIP-qPCR results confirmed that the lack of MSTN inhibited both the TCA cycle and OXPHOS, resulting in decreased ATP production. The reason may be that Smad2/3 is not sufficiently bound to the promoter region of the rate-limiting enzymes Idh2 and Idh3a of the TCA cycle, thus affecting their transcription.

Combined analysis of the proteome and metabolome provides insight into microRNA-1174 function in Aedes aegypti mosquitoes

“…PNP functions in pathways of purine, pyrimidine and niacin-nicotinamide metabolism; notably, the niacin-nicotinamide metabolism pathway can produce NADH. Further oxidative phosphorylation of NADH can produce a large amount of ATP to maintain life activities [ 38 , 39 ]. The expression of the PNP protein was significantly upregulated after the downregulation of miR-1174, suggesting that miR-1174 may directly or indirectly target PNP .…”

Roles of Myokines and Muscle-Derived Extracellular Vesicles in Musculoskeletal Deterioration under Disuse Conditions

“…Myostatin, the first identified myokine expressed in developing and mature muscles, exerts a negative regulatory role in muscle development [59]. Evidence has suggested that mice deficient in myostatin [60][61][62][63], mice treated with the myostatin inhibitor MID-35 [64], mice treated with myostatin monoclonal antibodies [65], cynomolgus monkeys treated with myostatin antibody GYM329 [66], and myostatin knockout cattle [67][68][69], dogs [70], and pigs [71,72] all exhibit higher muscle mass, implying that reducing myostatin expression in varying mammalian species markedly promotes muscle growth. Further research on the underlying mechanisms has indicated that myostatin depletion promotes myoblast proliferation and differentiation and increases muscle mass by elevating the expression of myogenic regulatory factors, including myogenic differentiation antigen (MyoD), myogenin (MyoG), and myogenic factor-5 (Myf-5) [27,28], activating the PI3K/protein kinase B (PKB, Akt)/mammalian target of rapamycin (mTOR) signaling pathway [27][28][29] while inhibiting the SMAD 2/3 pathway (the canonical pathway of myostatin) [30].…”

The Influence of Stress and Binge-Patterned Alcohol Drinking on Mouse Skeletal Muscle Protein Synthesis and Degradation Pathways

“…Alcohol misuse and chronic stress exposure can also increase myostatin, an activator of ubiquitin-proteasome-mediated protein degradation [15,48]. Therefore, we assessed changes in relative protein expression of the precursor myostatin protein (#sc-134345; Santa Cruz Biotechnology), commonly used to determine myostatin protein expression [49,50]. Ubiquitin (#20326; Cell Signaling Technology), as well as the relative protein expression of the E3 ligases MAFbx (#sc-166806; Santa Cruz Biotechnology) and MuRF-1 (#sc-398608; Santa Cruz Biotechnology), were also assessed.…”