Muscle differentiation is a crucial process controlling muscle development and homeostasis. Mitochondrial reactive oxygen species (mtROS) rapidly increase and function as critical cell signaling intermediates during the muscle differentiation. However, it has not yet been elucidated how they control myogenic signaling. Autophagy, a lysosome-mediated degradation pathway, is importantly recognized as intracellular remodeling mechanism of cellular organelles during muscle differentiation. Here, we demonstrated that the mtROS stimulated phosphatidylinositol 3 kinase/AKT/mammalian target of rapamycin (mTOR) cascade, and the activated mTORC1 subsequently induced autophagic signaling via phosphorylation of uncoordinated-51-like kinase 1 (ULK1) at serine 317 and upregulation of Atg proteins to prompt muscle differentiation. Treatment with MitoQ or rapamycin impaired both phosphorylation of ULK1 and expression of Atg proteins. Therefore, we propose a novel regulatory paradigm in which mtROS are required to initiate autophagic reconstruction of cellular organization through mTOR activation in muscle differentiation.
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Edited by E. Baehrecke
Bassel-Duby R, Olson EN. Signaling pathways in skeletal muscle remodeling. Annu Rev Biochem. 2006;75:19–37.
Florini JR, Ewton DZ, Coolican SA. Growth hormone and the insulin-like growth factor system in myogenesis. Endocr Rev. 1996;17:481–517.
Rodon J, Dienstmann R, Serra V, Tabernero J. Development of PI3K inhibitors: lessons learned from early clinical trials. Nat Rev Clin Oncol. 2013;10:143–53.
Vazquez F, Grossman SR, Takahashi Y, Rokas MV, Nakamura N, Sellers WR. Phosphorylation of the PTEN tail acts as an inhibitory switch by preventing its recruitment into a protein complex. J Biol Chem. 2001;276:48627–30.
Das S, Dixon JE, Cho W. Membrane-binding and activation mechanism of PTEN. Proc Natl Acad Sci USA. 2003;100:7491–6.
Kwon J, Lee SR, Yang KS, Ahn Y, Kim YJ, Stadtman ER, et al. Reversible oxidation and inactivation of the tumor suppressor PTEN in cells stimulated with peptide growth factors. Proc Natl Acad Sci USA. 2004;101:16419–24.
Kang KH, Lemke G, Kim JW. The PI3K-PTEN tug-of-war, oxidative stress and retinal degeneration. Trends Mol Med. 2009;15:191–8.
Laplante M, Sabatini DM. mTOR signaling in growth control and disease. Cell. 2012;149:274–93.
Braun T, Gautel M. Transcriptional mechanisms regulating skeletal muscle differentiation, growth and homeostasis. Nat Rev Mol Cell Biol. 2011;12:349–61.
Ma XM, Blenis J. Molecular mechanisms of mTOR-mediated translational control. Nat Rev Mol Cell Biol. 2009;10:307–18.
Nakatogawa H, Suzuki K, Kamada Y, Ohsumi Y. Dynamics and diversity in autophagy mechanisms: lessons from yeast. Nat Rev Mol Cell Biol. 2009;10:458–67.
Sarbassov DD, Guertin DA, Ali SM, Sabatini DM. Phosphorylation and regulation of Akt/PKB by the rictor-mTOR complex. Science. 2005;307:1098–101.
Kim YC, Guan KL. mTOR: a pharmacologic target for autophagy regulation. J Clin Invest. 2015;125:25–32.
Kim J, Kundu M, Viollet B, Guan KL. AMPK and mTOR regulate autophagy through direct phosphorylation of Ulk1. Nat Cell Biol. 2011;13:132–41.
Ravikumar B, Sarkar S, Davies JE, Futter M, Garcia-Arencibia M, Green-Thompson ZW, et al. Regulation of mammalian autophagy in physiology and pathophysiology. Physiol Rev. 2010;90:1383–435.
Janku F, McConkey DJ, Hong DS, Kurzrock R. Autophagy as a target for anticancer therapy. Nat Rev Clin Oncol. 2011;8:528–39.
Krauss S, Zhang CY, Lowell BB. The mitochondrial uncoupling-protein homologues. Nat Rev Mol Cell Biol. 2005;6:248–61.
Murphy MP. How mitochondria produce reactive oxygen species. Biochem J. 2009;417:1–13.
Lee S, Tak E, Lee J, Rashid MA, Murphy MP, Ha J, et al. Mitochondrial H2O2 generated from electron transport chain complex I stimulates muscle differentiation. Cell Res. 2011;21:817–34.
Tormos KV, Anso E, Hamanaka RB, Eisenbart J, Joseph J, Kalyanaraman B, et al. Mitochondrial complex III ROS regulate adipocyte differentiation. Cell Metab. 2011;14:537–44.
Hamanaka RB, Glasauer A, Hoover P, Yang S, Blatt H, Mullen AR, et al. Mitochondrial reactive oxygen species promote epidermal differentiation and hair follicle development. Sci Signal. 2013;6:ra8.
Del Prete A, Zaccagnino P, Di Paola M, Saltarella M, Oliveros Celis C, Nico B, et al. Role of mitochondria and reactive oxygen species in dendritic cell differentiation and functions. Free Radic Biol Med. 2008;44:1443–51.
Khacho M, Clark A, Svoboda DS, Azzi J, MacLaurin JG, Meghaizel C, et al. Mitochondrial dynamics impacts stem cell identity and fate decisions by regulating a nuclear transcriptional program. Cell Stem Cell. 2016;19:232–47.
Rhee SG. Cell signaling. H2O2, a necessary evil for cell signaling. Science. 2006;312:1882–3.
Wang Y, DuBois JL, Hedman B, Hodgson KO, Stack TD. Catalytic galactose oxidase models: biomimetic Cu(II)-phenoxyl-radical reactivity. Science. 1998;279:537–40.
Kalyanaraman B, Darley-Usmar V, Davies KJ, Dennery PA, Forman HJ, Grisham MB, et al. Measuring reactive oxygen and nitrogen species with fluorescent probes: challenges and limitations. Free Radic Biol Med. 2012;52:1–6.
Connor KM, Subbaram S, Regan KJ, Nelson KK, Mazurkiewicz JE, Bartholomew PJ, et al. Mitochondrial H2O2 regulates the angiogenic phenotype via PTEN oxidation. J Biol Chem. 2005;280:16916–24.
Wu KL, Wu CA, Wu CW, Chan SH, Chang AY, Chan JY. Redox-sensitive oxidation and phosphorylation of PTEN contribute to enhanced activation of PI3K/Akt signaling in rostral ventrolateral medulla and neurogenic hypertension in spontaneously hypertensive rats. Antioxid Redox Signal. 2013;18:36–50.
Crespo FL, Sobrado VR, Gomez L, Cervera AM, McCreath KJ. Mitochondrial reactive oxygen species mediate cardiomyocyte formation from embryonic stem cells in high glucose. Stem Cells. 2010;28:1132–42.
Yoon MS. mTOR as a key regulator in maintaining skeletal muscle mass. Front Physiol. 2017;8:788.
Sandri M. Autophagy in skeletal muscle. FEBS Lett. 2010;584:1411–6.
Martinez-Lopez N, Athonvarangkul D, Sahu S, Coletto L, Zong H, Bastie CC, et al. Autophagy in Myf5+ progenitors regulates energy and glucose homeostasis through control of brown fat and skeletal muscle development. EMBO Rep. 2013;14:795–803.
Forgac M. Vacuolar ATPases: rotary proton pumps in physiology and pathophysiology. Nat Rev Mol Cell Biol. 2007;8:917–29.
Fortini P, Ferretti C, Iorio E, Cagnin M, Garribba L, Pietraforte D, et al. The fine tuning of metabolism, autophagy and differentiation during in vitro myogenesis. Cell Death Dis. 2016;7:e2168.
Kim J, Guan KL. Regulation of the autophagy initiating kinase ULK1 by nutrients: roles of mTORC1 and AMPK. Cell Cycle. 2011;10:1337–8.
Hu Z, Wang H, Lee IH, Modi S, Wang X, Du J, et al. PTEN inhibition improves muscle regeneration in mice fed a high-fat diet. Diabetes. 2010;59:1312–20.
Vasilaki A, Jackson MJ. Role of reactive oxygen species in the defective regeneration seen in aging muscle. Free Radic Biol Med. 2013;65:317–23.
Ownby CL, Fletcher JE, Colberg TR. Cardiotoxin 1 from cobra (Naja naja atra) venom causes necrosis of skeletal muscle in vivo. Toxicon. 1993;31:697–709.
Lee J, Choi KJ, Lim MJ, Hong F, Choi TG, Tak E, et al. Proto-oncogenic H-Ras, K-Ras, and N-Ras are involved in muscle differentiation via phosphatidylinositol 3-kinase. Cell Res. 2010;20:919–34.
Remels AH, Langen RC, Schrauwen P, Schaart G, Schols AM, Gosker HR. Regulation of mitochondrial biogenesis during myogenesis. Mol Cell Endocrinol. 2010;315:113–20.
Malinska D, Kudin AP, Bejtka M, Kunz WS. Changes in mitochondrial reactive oxygen species synthesis during differentiation of skeletal muscle cells. Mitochondrion. 2012;12:144–8.
Song MS, Salmena L, Pandolfi PP. The functions and regulation of the PTEN tumour suppressor. Nat Rev Mol Cell Biol. 2012;13:283–96.
White ES, Atrasz RG, Hu B, Phan SH, Stambolic V, Mak TW, et al. Negative regulation of myofibroblast differentiation by PTEN (Phosphatase and Tensin Homolog Deleted on chromosome 10). Am J Respir Crit Care Med. 2006;173:112–21.
Yue F, Bi P, Wang C, Li J, Liu X, Kuang S. Conditional loss of Pten in myogenic progenitors leads to postnatal skeletal muscle hypertrophy but age-dependent exhaustion of satellite cells. Cell Rep. 2016;17:2340–53.
Erbay E, Chen J. The mammalian target of rapamycin regulates C2C12 myogenesis via a kinase-independent mechanism. J Biol Chem. 2001;276:36079–82.
Sun Y, Ge Y, Drnevich J, Zhao Y, Band M, Chen J. Mammalian target of rapamycin regulates miRNA-1 and follistatin in skeletal myogenesis. J Cell Biol. 2010;189:1157–69.
Ohanna M, Sobering AK, Lapointe T, Lorenzo L, Praud C, Petroulakis E, et al. Atrophy of S6K1(−/−) skeletal muscle cells reveals distinct mTOR effectors for cell cycle and size control. Nat Cell Biol. 2005;7:286–94.
Shu L, Houghton PJ. The mTORC2 complex regulates terminal differentiation of C2C12 myoblasts. Mol Cell Biol. 2009;29:4691–4700.
Jaafar R, Zeiller C, Pirola L, Di Grazia A, Naro F, Vidal H, et al. Phospholipase D regulates myogenic differentiation through the activation of both mTORC1 and mTORC2 complexes. J Biol Chem. 2011;286:22609–21.
Mizushima N, Levine B. Autophagy in mammalian development and differentiation. Nat Cell Biol. 2010;12:823–30.
This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2016R1D1A1B03933763 to TGC, and NRF-2011-0030072, NRF-2017R1A2B2007870, and NRF-2018R1A6A1A03025124 to SSK).