UBE2L3, a Partner of MuRF1/TRIM63, Is Involved in the Degradation of Myofibrillar Actin and Myosin

The ubiquitin proteasome system (UPS) is the main player of skeletal muscle wasting, a common characteristic of many diseases (cancer, etc.) that negatively impacts treatment and life prognosis. Within the UPS, the E3 ligase MuRF1/TRIM63 targets for degradation several myofibrillar proteins, including the main contractile proteins alpha-actin and myosin heavy chain (MHC). We previously identified five E2 ubiquitin-conjugating enzymes interacting with MuRF1, including UBE2L3/UbcH7, that exhibited a high affinity for MuRF1 (KD = 50 nM). Here, we report a main effect of UBE2L3 on alpha-actin and MHC degradation in catabolic C2C12 myotubes. Consistently UBE2L3 knockdown in Tibialis anterior induced hypertrophy in dexamethasone (Dex)-treated mice, whereas overexpression worsened the muscle atrophy of Dex-treated mice. Using combined interactomic approaches, we also characterized the interactions between MuRF1 and its substrates alpha-actin and MHC and found that MuRF1 preferentially binds to filamentous F-actin (KD = 46.7 nM) over monomeric G-actin (KD = 450 nM). By contrast with actin that did not alter MuRF1–UBE2L3 affinity, binding of MHC to MuRF1 (KD = 8 nM) impeded UBE2L3 binding, suggesting that differential interactions prevail with MuRF1 depending on both the substrate and the E2. Our data suggest that UBE2L3 regulates contractile proteins levels and skeletal muscle atrophy.

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UBE2E1 Is Preferentially Expressed in the Cytoplasm of Slow-Twitch Fibers and Protects Skeletal Muscles from Exacerbated Atrophy upon Dexamethasone Treatment

Cells ◽

10.3390/cells7110214 ◽

2018 ◽

Vol 7 (11) ◽

pp. 214 ◽

Cited By ~ 2

Author(s):

Cécile Polge ◽

Julien Aniort ◽

Andrea Armani ◽

Agnès Claustre ◽

Cécile Coudy-Gandilhon ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Mass ◽

Muscle Atrophy ◽

Tibialis Anterior Muscle ◽

Ubiquitin Proteasome System ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

Type I ◽

Dexamethasone Treatment ◽

Sarcomeric Protein

Skeletal muscle mass is reduced during many diseases or physiological situations (disuse, aging), which results in decreased strength and increased mortality. Muscle mass is mainly controlled by the ubiquitin-proteasome system (UPS), involving hundreds of ubiquitinating enzymes (E2s and E3s) that target their dedicated substrates for subsequent degradation. We recently demonstrated that MuRF1, an E3 ubiquitin ligase known to bind to sarcomeric proteins (telethonin, α-actin, myosins) during catabolic situations, interacts with 5 different E2 enzymes and that these E2-MuRF1 couples are able to target telethonin, a small sarcomeric protein, for degradation. Amongst the E2s interacting with MuRF1, E2E1 was peculiar as the presence of the substrate was necessary for optimal MuRF1-E2E1 interaction. In this work, we focused on the putative role of E2E1 during skeletal muscle atrophy. We found that E2E1 expression was restricted to type I and type IIA muscle fibers and was not detectable in type IIB fibers. This strongly suggests that E2E1 targets are fiber-specific and may be strongly linked to the contractile and metabolic properties of the skeletal muscle. However, E2E1 knockdown was not sufficient for preserving the protein content in C2C12 myotubes subjected to a catabolic state (dexamethasone treatment), suggesting that E2E1 is not involved in the development of muscle atrophy. By contrast, E2E1 knockdown aggravated the atrophying process in both catabolic C2C12 myotubes and the Tibialis anterior muscle of mice, suggesting that E2E1 has a protective effect on muscle mass.

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Fenofibrate, a PPARα agonist, decreases atrogenes and myostatin expression and improves arthritis-induced skeletal muscle atrophy

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00590.2010 ◽

2011 ◽

Vol 300 (5) ◽

pp. E790-E799 ◽

Cited By ~ 31

Author(s):

Estíbaliz Castillero ◽

María Paz Nieto-Bona ◽

Carmen Fernández-Galaz ◽

Ana Isabel Martín ◽

María López-Menduiña ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Skeletal Muscle ◽

Muscle Atrophy ◽

Ubiquitin Proteasome System ◽

Skeletal Muscle Atrophy ◽

Skeletal Muscle Wasting ◽

Cross Section Area ◽

Section Area ◽

Ubiquitin Proteasome ◽

Injection Control

Arthritis is a chronic inflammatory illness that induces cachexia, which has a direct impact on morbidity and mortality. Fenofibrate, a selective PPARα activator prescribed to treat human dyslipidemia, has been reported to decrease inflammation in rheumatoid arthritis patients. The aim of this study was to elucidate whether fenofibrate is able to ameliorate skeletal muscle wasting in adjuvant-induced arthritis, an experimental model of rheumatoid arthritis. On day 4 after adjuvant injection, control and arthritic rats were treated with 300 mg/kg fenofibrate until day 15, when all rats were euthanized. Fenofibrate decreased external signs of arthritis and liver TNFα and blocked arthritis-induced decreased in PPARα expression in the gastrocnemius muscle. Arthritis decreased gastrocnemius weight, which results from a decrease in cross-section area and myofiber size, whereas fenofibrate administration to arthritic rats attenuated the decrease in both gastrocnemius weight and fast myofiber size. Fenofibrate treatment prevented arthritis-induced increase in atrogin-1 and MuRF1 expression in the gastrocnemius. Neither arthritis nor fenofibrate administration modify Akt-FoxO3 signaling. Myostatin expression was not modified by arthritis, but fenofibrate decreased myostatin expression in the gastrocnemius of arthritic rats. Arthritis increased muscle expression of MyoD, PCNA, and myogenin in the rats treated with vehicle but not in those treated with fenofibrate. The results indicate that, in experimental arthritis, fenofibrate decreases skeletal muscle atrophy through inhibition of the ubiquitin-proteasome system and myostatin.

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Alpha-actin and cytochrome c mRNAs in atrophied adult rat skeletal muscle

AJP Cell Physiology ◽

10.1152/ajpcell.1988.254.5.c651 ◽

1988 ◽

Vol 254 (5) ◽

pp. C651-C656 ◽

Cited By ~ 36

Author(s):

P. Babij ◽

F. W. Booth

Keyword(s):

Skeletal Muscle ◽

Cytochrome C ◽

Muscle Atrophy ◽

Weight Bearing ◽

Skeletal Muscle Atrophy ◽

Rna Content ◽

Mrna Content ◽

Fast Twitch Muscle ◽

Alpha Actin ◽

Fast Twitch

Specific complementary DNA (cDNA) hybridization probes were used to estimate the levels of alpha-actin and cytochrome c mRNAs and also 18S rRNA in three models of skeletal muscle atrophy. After 7 days of hindlimb suspension, or immobilization, or denervation, protein content decreased 26-32% in all muscles studied except suspended fast-twitch muscle, which lost only half as much protein. alpha-Actin mRNA content decreased 51-66% and cytochrome c mRNA content decreased 42-61% in slow- and fast-twitch muscles in all three models of atrophy. However, total RNA content did not show similar directional changes; RNA content decreased 27-44% in suspended and immobilized muscle but was unchanged in denervated fast-twitch muscle. The results were interpreted to suggest that loss of weight-bearing function of skeletal muscle is a major factor affecting the levels of alpha-actin and cytochrome c mRNAs during muscle atrophy.

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Angiotensin (1-7) Decreases Myostatin-Induced NF-κB Signaling and Skeletal Muscle Atrophy

International Journal of Molecular Sciences ◽

10.3390/ijms21031167 ◽

2020 ◽

Vol 21 (3) ◽

pp. 1167 ◽

Cited By ~ 2

Author(s):

Javier Aravena ◽

Johanna Abrigo ◽

Francisco Gonzalez ◽

Francisco Aguirre ◽

Andrea Gonzalez ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Renin Angiotensin System ◽

Ubiquitin Proteasome System ◽

Skeletal Muscle Atrophy ◽

Gene Expressions ◽

Protein Levels ◽

Mas Receptor ◽

Signaling Activation ◽

Species Production

Myostatin is a myokine that regulates muscle function and mass, producing muscle atrophy. Myostatin induces the degradation of myofibrillar proteins, such as myosin heavy chain or troponin. The main pathway that mediates protein degradation during muscle atrophy is the ubiquitin proteasome system, by increasing the expression of atrogin-1 and MuRF-1. In addition, myostatin activates the NF-κB signaling pathway. Renin–angiotensin system (RAS) also regulates muscle mass. Angiotensin (1-7) (Ang-(1-7)) has anti-atrophic properties in skeletal muscle. In this paper, we evaluated the effect of Ang-(1-7) on muscle atrophy and signaling induced by myostatin. The results show that Ang-(1-7) prevented the decrease of the myotube diameter and myofibrillar protein levels induced by myostatin. Ang-(1-7) also abolished the increase of myostatin-induced reactive oxygen species production, atrogin-1, MuRF-1, and TNF-α gene expressions and NF-κB signaling activation. Ang-(1-7) inhibited the activity mediated by myostatin through Mas receptor, as is demonstrated by the loss of all Ang-(1-7)-induced effects when the Mas receptor antagonist A779 was used. Our results show that the effects of Ang-(1-7) on the myostatin-dependent muscle atrophy and signaling are blocked by MK-2206, an inhibitor of Akt/PKB. Together, these data indicate that Ang-(1-7) inhibited muscle atrophy and signaling induced by myostatin through a mechanism dependent on Mas receptor and Akt/PKB.

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Protective Effect of Pyropia yezoensis Peptide on Dexamethasone-Induced Myotube Atrophy in C2C12 Myotubes

Marine Drugs ◽

10.3390/md17050284 ◽

2019 ◽

Vol 17 (5) ◽

pp. 284 ◽

Cited By ~ 4

Author(s):

Min-Kyeong Lee ◽

Jeong-Wook Choi ◽

Youn Hee Choi ◽

Taek-Jeong Nam

Keyword(s):

Skeletal Muscle ◽

Growth Factor ◽

Signaling Pathway ◽

Muscle Atrophy ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

Protective Effects ◽

Factor I ◽

Igf I ◽

Foxo Signaling Pathway

Dexamethasone (DEX), a synthetic glucocorticoid, causes skeletal muscle atrophy. This study examined the protective effects of Pyropia yezoensis peptide (PYP15) against DEX-induced myotube atrophy and its association with insulin-like growth factor-I (IGF-I) and the Akt/mammalian target of rapamycin (mTOR)-forkhead box O (FoxO) signaling pathway. To elucidate the molecular mechanisms underlying the effects of PYP15 on DEX-induced myotube atrophy, C2C12 myotubes were treated for 24 h with 100 μM DEX in the presence or absence of 500 ng/mL PYP15. Cell viability assays revealed no PYP15 toxicity in C2C12 myotubes. PYP15 activated the insulin-like growth factor-I receptor (IGF-IR) and Akt-mTORC1 signaling pathway in DEX-induced myotube atrophy. In addition, PYP15 markedly downregulated the nuclear translocation of transcription factors FoxO1 and FoxO3a, and inhibited 20S proteasome activity. Furthermore, PYP15 inhibited the autophagy-lysosomal pathway in DEX-stimulated myotube atrophy. Our findings suggest that PYP15 treatment protected against myotube atrophy by regulating IGF-I and the Akt-mTORC1-FoxO signaling pathway in skeletal muscle. Therefore, PYP15 treatment appears to exert protective effects against skeletal muscle atrophy.

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Potential Therapeutic Role of L-Carnitine in Skeletal Muscle Oxidative Stress and Atrophy Conditions

Oxidative Medicine and Cellular Longevity ◽

10.1155/2015/646171 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 17

Author(s):

Anna Montesano ◽

Pamela Senesi ◽

Livio Luzi ◽

Stefano Benedini ◽

Ileana Terruzzi

Keyword(s):

Oxidative Stress ◽

Skeletal Muscle ◽

Morphological Changes ◽

Ubiquitin Proteasome System ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

Mitochondrial Activity ◽

Potential Therapeutic Role ◽

Essential Nutrient

The targeting of nutraceutical treatment to skeletal muscle damage is an emerging area of research, driven by the need for new therapies for a range of muscle-associated diseases. L-Carnitine (CARN) is an essential nutrient and plays a key role in mitochondrialβ-oxidation and in the ubiquitin-proteasome system regulation. As a dietary supplement to improve athletic performance, CARN has been studied for its potential to enhanceβ-oxidation. However, CARN effects on myogenesis, mitochondrial activity, and hypertrophy process are not completely elucidated. Thisin vitrostudy aims to investigate CARN role on skeletal muscle remodeling, differentiation process, and myotubes formation. We analyzed muscle differentiation and morphological features in C2C12 myoblasts exposed to 5 mM CARN. Our results showed that CARN was able to accelerate C2C12 myotubes formation and induce morphological changes, characterizing the start of hypertrophy process. In addition, CARN improved AKT activation and downstream cellular signaling pathways involved in skeletal muscle atrophy process prevention. Also, CARN positively regulated the pathways involved in oxidative stress defense. In this work, we provide an interesting novel mechanism of the potential therapeutic use of CARN to treat pathological conditions characterized by skeletal muscle morphological and functional impairment, oxidative stress production, and atrophy process in aging.

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Trimetazidine attenuates dexamethasone-induced muscle atrophy via inhibiting NLRP3/GSDMD pathway-mediated pyroptosis

Cell Death Discovery ◽

10.1038/s41420-021-00648-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Li Wang ◽

Xin-Feng Jiao ◽

Cheng Wu ◽

Xiao-Qing Li ◽

Hui-Xian Sun ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Muscle Performance ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

High Dose ◽

Protective Effects ◽

Akt Inhibitor ◽

Caspase 1

AbstractSkeletal muscle atrophy is one of the major side effects of high dose or sustained usage of glucocorticoids. Pyroptosis is a novel form of pro-inflammatory programmed cell death that may contribute to skeletal muscle injury. Trimetazidine, a well-known anti-anginal agent, can improve skeletal muscle performance both in humans and mice. We here showed that dexamethasone-induced atrophy, as evidenced by the increase of muscle atrophy F-box (Atrogin-1) and muscle ring finger 1 (MuRF1) expression, and the decrease of myotube diameter in C2C12 myotubes. Dexamethasone also induced pyroptosis, indicated by upregulated pyroptosis-related protein NLR family pyrin domain containing 3 (NLRP3), Caspase-1, and gasdermin-D (GSDMD). Knockdown of NLRP3 or GSDMD attenuated dexamethasone-induced myotube pyroptosis and atrophy. Trimetazidine treatment ameliorated dexamethasone-induced muscle pyroptosis and atrophy both in vivo and in vitro. Activation of NLRP3 using LPS and ATP not only increased the cleavage and activation of Caspase-1 and GSDMD, but also increased the expression levels of atrophy markers MuRF1 and Atrogin-1 in trimetazidine-treated C2C12 myotubes. Mechanically, dexamethasone inhibited the phosphorylation of PI3K/AKT/FoxO3a, which could be attenuated by trimetazidine. Conversely, co-treatment with a PI3K/AKT inhibitor, picropodophyllin, remarkably increased the expression of NLRP3 and reversed the protective effects of trimetazidine against dexamethasone-induced C2C12 myotube pyroptosis and atrophy. Taken together, our study suggests that NLRP3/GSDMD-mediated pyroptosis might be a novel mechanism for dexamethasone-induced skeletal muscle atrophy. Trimetazidine might be developed as a potential therapeutic agent for the treatment of dexamethasone-induced muscle atrophy.

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MicroRNA 322 Aggravates Dexamethasone-Induced Muscle Atrophy by Targeting IGF1R and INSR

International Journal of Molecular Sciences ◽

10.3390/ijms21031111 ◽

2020 ◽

Vol 21 (3) ◽

pp. 1111 ◽

Cited By ~ 1

Author(s):

Hongwei Geng ◽

Qinglong Song ◽

Yunyun Cheng ◽

Haoyang Li ◽

Rui Yang ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Target Genes ◽

Immunosuppressive Agent ◽

Skeletal Muscle Atrophy ◽

Luciferase Reporter ◽

C2c12 Myotubes ◽

High Dose ◽

Reporter Assays ◽

Underlying Mechanisms

Dexamethasone (Dex) has been widely used as a potent anti-inflammatory, antishock, and immunosuppressive agent. However, high dose or long-term use of Dex is accompanied by side effects including skeletal muscle atrophy, whose underlying mechanisms remain incompletely understood. A number of microRNAs (miRNAs) have been shown to play key roles in skeletal muscle atrophy. Previous studies showed significantly increased miR-322 expression in Dex-treated C2C12 myotubes. In our study, the glucocorticoid receptor (GR) was required for Dex to increase miR-322 expression in C2C12 myotubes. miR-322 mimic or miR-322 inhibitor was used for regulating the expression of miR-322. Insulin-like growth factor 1 receptor (IGF1R) and insulin receptor (INSR) were identified as target genes of miR-322 using luciferase reporter assays and played key roles in Dex-induced muscle atrophy. miR-322 overexpression promoted atrophy in Dex-treated C2C12 myotubes and the gastrocnemius muscles of mice. Conversely, miR-322 inhibition showed the opposite effects. These data suggested that miR-322 contributes to Dex-induced muscle atrophy via targeting of IGF1R and INSR. Furthermore, miR-322 might be a potential target to counter Dex-induced muscle atrophy. miR-322 inhibition might also represent a therapeutic approach for Dex-induced muscle atrophy.

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miR-23a is decreased during muscle atrophy by a mechanism that includes calcineurin signaling and exosome-mediated export

AJP Cell Physiology ◽

10.1152/ajpcell.00266.2013 ◽

2014 ◽

Vol 306 (6) ◽

pp. C551-C558 ◽

Cited By ~ 74

Author(s):

Matthew B. Hudson ◽

Myra E. Woodworth-Hobbs ◽

Bin Zheng ◽

Jill A. Rahnert ◽

Mitsi A. Blount ◽

...

Keyword(s):

Skeletal Muscle ◽

Muscle Atrophy ◽

Ring Finger ◽

Skeletal Muscle Atrophy ◽

C2c12 Myotubes ◽

Activated T Cells ◽

Streptozotocin Induced Diabetes ◽

The Media ◽

The Relationship ◽

Deficient Mice

Skeletal muscle atrophy is prevalent in chronic diseases, and microRNAs (miRs) may play a key role in the wasting process. miR-23a was previously shown to inhibit the expression of atrogin-1 and muscle RING-finger protein-1 (MuRF1) in muscle. It also was reported to be regulated by cytoplasmic nuclear factor of activated T cells 3 (NFATc3) in cardiomyocytes. The objective of this study was to determine if miR-23a is regulated during muscle atrophy and to evaluate the relationship between calcineurin (Cn)/NFAT signaling and miR-23a expression in skeletal muscle cells during atrophy. miR-23a was decreased in the gastrocnemius of rats with acute streptozotocin-induced diabetes, a condition known to increase atrogin-1 and MuRF1 expression and cause atrophy. Treatment of C2C12 myotubes with dexamethasone (Dex) for 48 h also reduced miR-23a as well as RCAN1.4 mRNA, which is transcriptionally regulated by NFAT. NFATc3 nuclear localization and the amount of miR-23a decreased rapidly within 1 h of Dex administration, suggesting a link between Cn signaling and miR-23a. The level of miR-23a was lower in primary myotubes from mice lacking the α- or β-isoform of the CnA catalytic subunit than wild-type mice. Dex did not further suppress miR-23a in myotubes from Cn-deficient mice. Overexpression of CnAβ in C2C12 myotubes prevented Dex-induced suppression of miR-23a. Finally, miR-23a was present in exosomes isolated from the media of C2C12 myotubes, and Dex increased its exosomal abundance. Dex did not alter the number of exosomes released into the media. We conclude that atrophy-inducing conditions downregulate miR-23a in muscle by mechanisms involving attenuated Cn/NFAT signaling and selective packaging into exosomes.

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