scholarly journals PGC-1β prevents statin-associated myotoxicity in oxidative skeletal muscle

2017 ◽  
Author(s):  
François Singh ◽  
Joffrey Zoll ◽  
Urs Duthaler ◽  
Anne-Laure Charles ◽  
Gilles Laverny ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Rat Skeletal Muscle ◽  
Oxidative Defense ◽  
Muscle Types ◽  
And Function

AbstractStatins are generally well-tolerated, but can induce myopathy. Statins are associated with impaired expression of PGC-1β in human and rat skeletal muscle. The current study was performed to investigate the relation between PGC-1β expression and function and statin-associated myopathy. In WT mice, atorvastatin impaired mitochondrial function in glycolytic, but not in oxidative muscle. In PGC-1β KO mice, atorvastatin induced a shift from oxidative type IIA to glycolytic type IIB myofibers mainly in oxidative muscle and mitochondrial dysfunction was observed in both muscle types. In glycolytic muscle of WT and KO mice and in oxidative muscle of KO mice, atorvastatin suppressed mitochondrial proliferation and oxidative defense, leading to apoptosis. In contrast, mitochondrial function was maintained or improved and apoptosis decreased by atorvastatin in oxidative muscle of WT mice. In conclusion, PGC-1β has an important role in preventing damage to oxidative muscle in the presence of a mitochondrial toxicant such as atorvastatin.

scholarly journals Mitochondrial dysfunction and consequences in calpain-3-deficient muscle

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vanessa E. Jahnke ◽  
Jennifer M. Peterson ◽  
Jack H. Van Der Meulen ◽  
Jessica Boehler ◽  
Kitipong Uaesoontrachoon ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Mitochondrial Activity ◽  
Calpain 3 ◽  
And Function ◽  
Deficient Mice

Abstract Background Nonsense or loss-of-function mutations in the non-lysosomal cysteine protease calpain-3 result in limb-girdle muscular dystrophy type 2A (LGMD2A). While calpain-3 is implicated in muscle cell differentiation, sarcomere formation, and muscle cytoskeletal remodeling, the physiological basis for LGMD2A has remained elusive. Methods Cell growth, gene expression profiling, and mitochondrial content and function were analyzed using muscle and muscle cell cultures established from healthy and calpain-3-deficient mice. Calpain-3-deficient mice were also treated with PPAR-delta agonist (GW501516) to assess mitochondrial function and membrane repair. The unpaired t test was used to assess the significance of the differences observed between the two groups or treatments. ANOVAs were used to assess significance over time. Results We find that calpain-3 deficiency causes mitochondrial dysfunction in the muscles and myoblasts. Calpain-3-deficient myoblasts showed increased proliferation, and their gene expression profile showed aberrant mitochondrial biogenesis. Myotube gene expression analysis further revealed altered lipid metabolism in calpain-3-deficient muscle. Mitochondrial defects were validated in vitro and in vivo. We used GW501516 to improve mitochondrial biogenesis in vivo in 7-month-old calpain-3-deficient mice. This treatment improved satellite cell activity as indicated by increased MyoD and Pax7 mRNA expression. It also decreased muscle fatigability and reduced serum creatine kinase levels. The decreased mitochondrial function also impaired sarcolemmal repair in the calpain-3-deficient skeletal muscle. Improving mitochondrial activity by acute pyruvate treatment improved sarcolemmal repair. Conclusion Our results provide evidence that calpain-3 deficiency in the skeletal muscle is associated with poor mitochondrial biogenesis and function resulting in poor sarcolemmal repair. Addressing this deficit by drugs that improve mitochondrial activity offers new therapeutic avenues for LGMD2A.

scholarly journals Two Weeks of Smoking Cessation Reverse Cigarette Smoke-Induced Skeletal Muscle Atrophy and Mitochondrial Dysfunction in Mice

2020 ◽  
Author(s):  
Tom Tanjeko Ajime ◽  
Jef Serré ◽  
Rob C I Wüst ◽  
Guy Anselme Mpaka Messa ◽  
Chiel Poffé ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Smoking Cessation ◽  
Mitochondrial Dysfunction ◽  
Muscle Mass ◽  
Muscle Atrophy ◽  
Skeletal Muscles ◽  
Skeletal Muscle Atrophy ◽  
Limb Muscle ◽  
Male Mice ◽  
And Function

Abstract Introduction Apart from its adverse effects on the respiratory system, cigarette smoking also induces skeletal muscle atrophy and dysfunction. Whether short-term smoking cessation can restore muscle mass and function is unknown. We, therefore, studied the impact of 1- and 2-week smoking cessation on skeletal muscles in a mouse model. Methods Male mice were divided into four groups: Air-exposed (14 weeks); cigarette smoke (CS)-exposed (14 weeks); CS-exposed (13 weeks) followed by 1-week cessation; CS-exposed (12 weeks) followed by 2 weeks cessation to examine exercise capacity, physical activity levels, body composition, muscle function, capillarization, mitochondrial function and protein expression in the soleus, plantaris, and diaphragm muscles. Results CS-induced loss of body and muscle mass was significantly improved within 1 week of cessation due to increased lean and fat mass. Mitochondrial respiration and protein levels of the respiratory complexes in the soleus were lower in CS-exposed mice, but similar to control values after 2 weeks of cessation. Exposing isolated soleus muscles to CS extracts reduced mitochondrial respiration that was reversed after removing the extract. While physical activity was reduced in all groups, exercise capacity, limb muscle force, fatigue resistance, fiber size and capillarization, and diaphragm cytoplasmic HIF-1α were unaltered by CS-exposure. However, CS-induced diaphragm atrophy and increased capillary density were not seen after 2 weeks of smoking cessation. Conclusion In male mice, 2 weeks of smoking cessation reversed smoking-induced mitochondrial dysfunction, limb muscle mass loss, and diaphragm muscle atrophy, highlighting immediate benefits of cessation on skeletal muscles. Implications Our study demonstrates that CS-induced skeletal muscle mitochondrial dysfunction and atrophy are significantly improved by 2 weeks of cessation in male mice. We show for the first time that smoking cessation as short as 1 to 2 weeks is associated with immediate beneficial effects on skeletal muscle structure and function with the diaphragm being particularly sensitive to CS-exposure and cessation. This could help motivate smokers to quit smoking as early as possible. The knowledge that smoking cessation has potential positive extrapulmonary effects is particularly relevant for patients referred to rehabilitation programs and those admitted to hospitals suffering from acute or chronic muscle deterioration yet struggling with smoking cessation.

αvβ3- and α5β1-integrin blockade inhibits myogenic constriction of skeletal muscle resistance arterioles

2005 ◽  
Vol 289 (1) ◽  
pp. H322-H329 ◽  
Author(s):  
Luis A. Martinez-Lemus ◽  
Tracy Crow ◽  
Michael J. Davis ◽  
Gerald A. Meininger
Keyword(s):  
Skeletal Muscle ◽  
Vessel Diameter ◽  
Significant Inhibition ◽  
Intraluminal Pressure ◽  
Rat Skeletal Muscle ◽  
Histocompatibility Complex ◽  
Spontaneous Tone ◽  
And Function ◽  
Blocking Antibodies ◽  
Α5β1 Integrin

In isolated resistance arterioles with spontaneous tone, ligation of α4β1- and α5β1-integrins induces vasoconstriction whereas ligation of αvβ3-integrin induces vasodilation. However, whether integrins directly participate in myogenic constriction to pressure elevation is not known. To answer this question, isolated rat skeletal muscle arterioles were exposed to step increments in pressure in the absence or presence of peptides and function-blocking antibodies known to bind α4β1-, α5β1-, or αvβ3-integrins while vessel diameter was continually monitored. Myogenic constriction, as assessed by the ability of isolated arterioles to reduce their diameter in response to two consecutive increments in intraluminal pressure (90–110 and 110–130 cmH2O), was not affected by treatment with any of the control peptides (RAD, LEV), a control antibody (anti-rat major histocompatibility complex), an α4β1-integrin-binding peptide (LDV), or an anti-α4-integrin antibody. In contrast, α5β1-integrin blockade with either anti-α5- or anti-β1-integrin antibody caused a significant inhibition of myogenic constriction. Also, both RGD peptide and anti-β3-integrin antibody inhibited myogenic constriction. These results indicate that α5β1- and αvβ3-integrins are necessary for myogenic constriction and further suggest that integrins are part of the mechanosensory apparatus responsible for the ability of vascular smooth muscle cells to detect and/or respond to changes in intraluminal pressure.

scholarly journals Effect of electrical stimulation-induced resistance exercise on mitochondrial fission and fusion proteins in rat skeletal muscle

2015 ◽  
Vol 40 (11) ◽  
pp. 1137-1142 ◽  
Author(s):  
Yu Kitaoka ◽  
Riki Ogasawara ◽  
Yuki Tamura ◽  
Satoshi Fujita ◽  
Hideo Hatta
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Resistance Exercise ◽  
Mitochondrial Function ◽  
Muscle Protein ◽  
Mitochondrial Dynamics ◽  
Muscle Protein Synthesis ◽  
Mitochondrial Fission ◽  
Dynamic Networks ◽  
Rat Skeletal Muscle

It is well known that resistance exercise increases muscle protein synthesis and muscle strength. However, little is known about the effect of resistance exercise on mitochondrial dynamics, which is coupled with mitochondrial function. In skeletal muscle, mitochondria exist as dynamic networks that are continuously remodeling through fusion and fission. The purpose of this study was to investigate the effect of acute and chronic resistance exercise, which induces muscle hypertrophy, on the expression of proteins related to mitochondrial dynamics in rat skeletal muscle. Resistance exercise consisted of maximum isometric contraction, which was induced by percutaneous electrical stimulation of the gastrocnemius muscle. Our results revealed no change in levels of proteins that regulate mitochondrial fission (Fis1 and Drp1) or fusion (Opa1, Mfn1, and Mfn2) over the 24-h period following acute resistance exercise. Phosphorylation of Drp1 at Ser616 was increased immediately after exercise (P < 0.01). Four weeks of resistance training (3 times/week) increased Mfn1 (P < 0.01), Mfn2 (P < 0.05), and Opa1 (P < 0.01) protein levels without altering mitochondrial oxidative phosphorylation proteins. These observations suggest that resistance exercise has little effect on mitochondrial biogenesis but alters the expression of proteins involved in mitochondrial fusion and fission, which may contribute to mitochondrial quality control and improved mitochondrial function.

scholarly journals Breast cancer-associated skeletal muscle mitochondrial dysfunction and lipid accumulation is reversed by PPARG

2021 ◽  
Author(s):  
Hannah E. Wilson ◽  
David A. Stanton ◽  
Stephanie Rellick ◽  
Werner Geldenhuys ◽  
Emidio E. Pistilli
Keyword(s):  
Breast Cancer ◽  
Skeletal Muscle ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Function ◽  
Lipid Accumulation ◽  
Transcriptional Activity ◽  
Target Genes ◽  
Ppar Gamma ◽  
Peroxisome Proliferator ◽  
Independent Functions

The peroxisome-proliferator activated receptors (PPARs) have been previously implicated in the pathophysiology of skeletal muscle dysfunction in women with breast cancer (BC) and in animal models of BC. This study investigated alterations induced in skeletal muscle by BC-derived factors in an in vitro conditioned media (CM) system and tested the hypothesis that BC cells secrete a factor that represses PPAR-gamma (PPARG) expression and its transcriptional activity, leading to downregulation of PPARG target genes involved in mitochondrial function and other metabolic pathways. We found that BC-derived factors repress PPAR-mediated transcriptional activity without altering protein expression of PPARG. Further, we show that BC-derived factors induce significant alterations in skeletal muscle mitochondrial function and lipid accumulation, which are rescued with exogenous expression of PPARG. The PPARG agonist drug rosiglitazone was able to rescue BC-induced lipid accumulation, but did not rescue effects of BC-derived factors on PPAR-mediated transcription or mitochondrial function. These data suggest that BC-derived factors alter lipid accumulation and mitochondrial function via different mechanisms that are both related to PPARG signaling, with mitochondrial dysfunction likely being altered via repression of PPAR-mediated transcription, and lipid accumulation being altered via transcription-independent functions of PPARG.

scholarly journals Mitochondria-Cytokine Crosstalk Following Skeletal Muscle Injury and Disuse: A Mini-Review

2021 ◽  
Author(s):  
Anita E. Qualls ◽  
W. Michael Southern ◽  
Jarrod A. Call
Keyword(s):  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Muscle Injury ◽  
Muscle Injuries ◽  
Monocyte Chemoattractant Protein 1 ◽  
Skeletal Muscle Injury ◽  
Atp Production ◽  
Bona Fide ◽  
Sense And Respond ◽  
And Function

Skeletal muscle mitochondria are highly adaptable, highly dynamic organelles that maintain the functional integrity of the muscle fiber by providing ATP for contraction and cellular homeostasis (e.g., Na+/K+ ATPase). Emerging as early modulators of inflammation, mitochondria sense and respond to cellular stress. Mitochondria communicate with the environment, in part, by release of physical signals called mitochondrial-derived damage-associated molecular patterns (mito-DAMPs) and deviation from routine function (e.g. reduced ATP production, Ca2+ overload). When skeletal muscle is compromised, mitochondria contribute to an acute inflammatory response necessary for myofibril regeneration; however, exhaustive signaling associated with altered or reduced mitochondrial function can be detrimental to muscle outcomes. Here we describe changes in mitochondrial content, structure, and function following skeletal muscle injury and disuse and highlight the influence of mitochondrial-cytokine crosstalk on muscle regeneration and recovery. While the appropriate therapeutic modulation following muscle stressors remains unknown, retrospective gene expression analysis reveal interleukin-6 (IL-6), interleukin-1b (IL-1b), chemokine C-X-C motif ligand 1 (CXCL1), and monocyte chemoattractant protein 1 (MCP-1) are significantly upregulated following three unique muscle injuries. These cytokines modulate mitochondrial function and execute bona fide pleiotropic roles that can aid functional recovery of muscle; however, when aberrant, chronically disrupt healing partly by exacerbating mitochondrial dysfunction. Multidisciplinary efforts to delineate the opposing regulatory roles of inflammatory cytokines in the muscle-mitochondrial environment are required to modulate regenerative behavior following skeletal muscle injury or disuse. Future therapeutic directions to consider include quenching or limited release of mito-DAMPs and cytokines present in cytosol or circulation.

scholarly journals Skeletal Muscle Mitochondrial Dysfunction Is Present in Patients with CKD before Initiation of Maintenance Hemodialysis

2020 ◽  
Vol 15 (7) ◽  
pp. 926-936 ◽  
Author(s):  
Jorge L. Gamboa ◽  
Baback Roshanravan ◽  
Theodore Towse ◽  
Chad A. Keller ◽  
Aaron M. Falck ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Mitochondrial Dysfunction ◽  
Physical Performance ◽  
Mitochondrial Function ◽  
Maintenance Hemodialysis ◽  
Intermuscular Adipose Tissue ◽  
Markers Of Inflammation ◽  
And Oxidative Stress

Background and objectivesPatients with CKD suffer from frailty and sarcopenia, which is associated with higher morbidity and mortality. Skeletal muscle mitochondria are important for physical function and could be a target to prevent frailty and sarcopenia. In this study, we tested the hypothesis that mitochondrial dysfunction is associated with the severity of CKD. We also evaluated the interaction between mitochondrial function and coexisting comorbidities, such as impaired physical performance, intermuscular adipose tissue infiltration, inflammation, and oxidative stress.Design, setting, participants, & measurements Sixty-three participants were studied, including controls (n=21), patients with CKD not on maintenance hemodialysis (CKD 3–5; n=20), and patients on maintenance hemodialysis (n=22). We evaluated in vivo knee extensors mitochondrial function using 31P magnetic resonance spectroscopy to obtain the phosphocreatine recovery time constant, a measure of mitochondrial function. We measured physical performance using the 6-minute walk test, intermuscular adipose tissue infiltration with magnetic resonance imaging, and markers of inflammation and oxidative stress in plasma. In skeletal muscle biopsies from a select number of patients on maintenance hemodialysis, we also measured markers of mitochondrial dynamics (fusion and fission).ResultsWe found a prolonged phosphocreatine recovery constant in patients on maintenance hemodialysis (53.3 [43.4–70.1] seconds, median [interquartile range]) and patients with CKD not on maintenance hemodialysis (41.5 [35.4–49.1] seconds) compared with controls (38.9 [32.5–46.0] seconds; P=0.001 among groups). Mitochondrial dysfunction was associated with poor physical performance (r=0.62; P=0.001), greater intermuscular adipose tissue (r=0.44; P=0.001), and increased markers of inflammation and oxidative stress (r=0.60; P=0.001). We found mitochondrial fragmentation and increased content of dynamin-related protein 1, a marker of mitochondrial fission, in skeletal muscles from patients on maintenance hemodialysis (0.86 [0.48–1.35] arbitrary units (A.U.), median [interquartile range]) compared with controls (0.60 [0.24–0.75] A.U.).ConclusionsMitochondrial dysfunction is due to multifactorial etiologies and presents prior to the initiation of maintenance hemodialysis, including in patients with CKD stages 3–5.

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