NRF2 Regulates Viability, Proliferation, Resistance to Oxidative Stress, and Differentiation of Murine Myoblasts and Muscle Satellite Cells

Abstract

Increased oxidative stress can slow down the regeneration of skeletal muscle and affect the activity of muscle satellite cells (mSCs). Therefore, we evaluated the role of the NRF2 transcription factor (encoded by the Nfe2l2 gene), the main regulator of the antioxidant response, in muscle cell biology. We used (i) an immortalized murine myoblast cell line (C2C12) with stable overexpression of NRF2 and (ii) primary mSCs isolated from wild-type and Nfe2l2 (transcriptionally)-deficient mice (Nfe2l2tKO). NRF2 promoted myoblast proliferation and viability under oxidative stress conditions and decreased the production of reactive oxygen species. Furthermore, NRF2 overexpression inhibited C2C12 cell differentiation by down-regulating the expression of myogenic regulatory factors (MRFs) and muscle-specific microRNAs. We also showed that NRF2 is indispensable for the viability of mSCs since the lack of its transcriptional activity caused high mortality of cells cultured in vitro under normoxic conditions. Concomitantly, Nfe2l2tKO mSCs grown and differentiated under hypoxic conditions were viable and much more differentiated compared to cells isolated from wild-type mice. Taken together, NRF2 significantly influences the properties of myoblasts and muscle satellite cells. This effect might be modulated by the muscle microenvironment.

Deletion of Dux ameliorates muscular dystrophy in mdx mice by attenuating oxidative stress via Nrf2

“…oxstress can affect muscle satellite cell activity, proliferative capacity, and myotube formation. 14 Our results show that knockout of Dux suppressed the high oxidative stress state in muscle satellite cells isolated from mdx mice and also improved mitochondrial function. In addition, knockout of Dux increased the viability and proliferation of muscle satellite cells from mdx mice, and also reduced cell apoptosis and necrosis.…”

“…Muscle satellite cells are very important for muscle regeneration by differentiating to form myotubes, and correcting satellite cell function and promoting satellite cell survival appear to be treatments for DMD 37 . Increased oxidative stress can affect muscle satellite cell activity, proliferative capacity, and myotube formation 14 . Our results show that knockout of Dux suppressed the high oxidative stress state in muscle satellite cells isolated from mdx mice and also improved mitochondrial function.…”

“…Nuclear factor erythroid 2‐related factor 2 (Nrf2) is a transcription factor that plays a key role in the oxidative stress response 13 . Nrf2 reduced the production of reactive oxygen species (ROS), promoted the proliferation and viability of myoblasts, and it appeared to be essential for the survival of muscle satellite cells 14 . Importantly, a recent review focused on the possibility that targeting Nrf2 may modulate multiple pathological features of DMD through different pathways, which may extend the therapeutic benefit 15 …”

“…13 Nrf2 reduced the production of reactive oxygen species (ROS), promoted the proliferation and viability of myoblasts, and it appeared to be essential for the survival of muscle satellite cells. 14 Importantly, a recent review focused on the possibility that targeting Nrf2 may modulate multiple pathological features of DMD through different pathways, which may extend the therapeutic benefit. 15 Double homeobox protein 4 (DUX4) is normally expressed during embryonic development and in the human testis, but is repressed in somatic tissues.…”

Oxidative Stress and Skeletal Muscle Function

“…This negative phenomenon is due to the induction of overt inflammation and fibrosis, especially in pathological conditions such as advanced progressive diabetic nephropathy (DN) [ 10 ]. Satellite cells are particularly sensitive to oxidative stress [ 11 ]. Quiescent satellite cells are activated to repair skeletal muscle damage undergoing active proliferation, and then differentiate into myoblasts and regenerate myofibers.…”