Dietary resveratrol confers apoptotic resistance to oxidative stress in myoblasts

Abstract

High levels of reactive oxygen species (ROS) contributes to muscle cell death in aging and disuse. We have previously found that resveratrol can reduce oxidative stress in response to aging and hindlimb unloading in rodents in vivo, but it was not known if resveratrol would protect muscle stem cells during repair or regeneration when oxidative stress is high. To test the protective role of resveratrol on muscle stem cells directly, we treated the C2C12 mouse myoblast cell line with moderate (100 μM) or very high (1 mM) levels of H2O2; in the presence or absence of resveratrol. The p21 promoter activity declined in myoblasts in response to high ROS and this was accompanied a greater nuclear to cytoplasmic translocation of p21 in a dose dependent matter in myoblasts as compared to myotubes. Apoptosis, as indicated by TdT-mediated dUTP nick-end (TUNEL) labeling was greater in C2C12 myoblasts as compared to myotubes (P< 0.05) after treatment with H2O2. Caspase-9, -8, and -3 activities were elevated significantly (P< 0.05) in myoblasts treated with H2O2. Myoblasts were more susceptible to ROS-induced oxidative stress than myotubes. We treated C2C12 myoblasts with 50 μM of resveratrol for periods up to 48 h to determine if myoblasts could be rescued from high ROS-induced apoptosis by resveratrol. Resveratrol reduced the apoptotic index, and significantly reduced the ROS-induced caspase-9, -8, and -3 activity in myoblasts. Furthermore, Bcl-2 and the Bax/Bcl-2 ratio were partially rescued in myoblasts by resveratrol treatment. Similarly, muscle stem cells isolated from mouse skeletal muscles showed reduced Sirt1 protein abundance with H2O2 treatment but this could be reversed by resveratrol. Reduced apoptotic susceptibility in myoblasts as compared to myotubes to ROS is regulated at least in part, by enhanced p21 promoter activity and nuclear p21 location in myotubes. Resveratrol confers further protection against ROS by improving Sirt1 levels and increasing antioxidant production, which reduces mitochondrial associated apoptotic signaling, and cell death in myoblasts.

Honokiol ameliorates oxidative stress-induced DNA damage and apoptosis of c2c12 myoblasts by ROS generation and mitochondrial pathway

“…Therefore, the balance of apoptotic Bax family proteins to the antiapoptotic Bcl-2 family proteins serves as a determinant for activating or inhibiting the intrinsic apoptosis pathway. Many previous studies have shown that the induction of apoptosis by H 2 O 2 in C2C12 cells was associated with a decrease in the Bcl-2/Bax ratio and/ or activation of caspases (Siu et al 2009;Haramizu et al 2017). Consistent with previous findings, our results also showed that the cytosolic release of cytochrome c, and the decreased expression of Bcl-2 and increased expression of Bax observed in H 2 O 2 -treated cells abolished in the presence of honokiol.…”

Resveratrol decreases cell apoptosis through inhibiting DNA damage in bronchial epithelial cells

“…ROS have been shown to inactivate histone deacetylase-2, which is an essential factor for the inflammatory response (41). RES can improve the expression level of SIRT1 and increase antioxidant production to reduce mitochondrial-associated apoptotic signaling pathways and cell apoptosis and prevent ROS-induced cell damage in myoblasts (42). In the present study, high expression levels of 8-OHdG/8-oxoG were detected, which indicated that the bronchial epithelial cells were damaged.…”

The role of SIRT1 in skeletal muscle function and repair of older mice

“…As resveratrol‐mediated SIRT1 activation was shown to be protective against ROS‐induced mitochondrial‐mediated apoptotic signalling in muscle, and SIRT1 increases antioxidant production in muscle, we had expected that mitochondrial function would be improved in muscles that overexpressed SIRT1 after repair following CTX injury mice. However, muscles from OE‐80 animals had the lowest SSM‐ΔΨm and SSM ATP synthase activity.…”

“…Protein concentrations of samples were determined by the Lowry method, and the purity of each fraction was confirmed as reported previously . Forty micrograms of protein were loaded into each well of a 4–12% gradient polyacrylamide gel (Invitrogen, Carlsbad, CA) and separated by routine sodium dodecyl sulfate‐polyacrylamide gel electrophoresis for 1 h at 120 V. The proteins were transferred to a nitrocellulose membrane for 1.5 h at 25 V. Non‐specific protein binding was blocked by incubating the membranes in 5% nonfat milk in Tris‐buffered saline containing 0.05% Tween 20 …”

“…Skeletal muscle lysates were analysed with Western immunoblots as previously described, with slight modifications. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis was run on 4–12% gradient NuPAGE Bis‐Tris gels (ThermoFisher Scientific, Pittsburgh PA, USA) at 120 V for 2 h in NuPAGE MES SDS buffer (ThermoFisher Scientific, Pittsburgh PA, USA).…”