scholarly journals Sustained Systemic Levels of IL-6 Impinge Early Muscle Growth and Induce Muscle Atrophy and Wasting in Adulthood

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1816
Author(s):  
Laura Pelosi ◽  
Maria Grazia Berardinelli ◽  
Laura Forcina ◽  
Francesca Ascenzi ◽  
Emanuele Rizzuto ◽  
...  

IL-6 is a pleiotropic cytokine that can exert different and opposite effects. The muscle-induced and transient expression of IL-6 can act in an autocrine or paracrine manner, stimulating anabolic pathways associated with muscle growth, myogenesis, and with regulation of energy metabolism. In contrast, under pathologic conditions, including muscular dystrophy, cancer associated cachexia, aging, chronic inflammatory diseases, and other pathologies, the plasma levels of IL-6 significantly increase, promoting muscle wasting. Nevertheless, the specific physio-pathological role exerted by IL-6 in the maintenance of differentiated phenotype remains to be addressed. The purpose of this study was to define the role of increased plasma levels of IL-6 on muscle homeostasis and the mechanisms contributing to muscle loss. Here, we reported that increased plasma levels of IL-6 promote alteration in muscle growth at early stage of postnatal life and induce muscle wasting by triggering a shift of the slow-twitch fibers toward a more sensitive fast fiber phenotype. These findings unveil a role for IL-6 as a potential biomarker of stunted growth and skeletal muscle wasting.

2011 ◽  
Vol 300 (6) ◽  
pp. H1973-H1982 ◽  
Author(s):  
Astrid Breitbart ◽  
Mannix Auger-Messier ◽  
Jeffery D. Molkentin ◽  
Joerg Heineke

A significant proportion of heart failure patients develop skeletal muscle wasting and cardiac cachexia, which is associated with a very poor prognosis. Recently, myostatin, a cytokine from the transforming growth factor-β (TGF-β) family and a known strong inhibitor of skeletal muscle growth, has been identified as a direct mediator of skeletal muscle atrophy in mice with heart failure. Myostatin is mainly expressed in skeletal muscle, although basal expression is also detectable in heart and adipose tissue. During pathological loading of the heart, the myocardium produces and secretes myostatin into the circulation where it inhibits skeletal muscle growth. Thus, genetic elimination of myostatin from the heart reduces skeletal muscle atrophy in mice with heart failure, whereas transgenic overexpression of myostatin in the heart is capable of inducing muscle wasting. In addition to its endocrine action on skeletal muscle, cardiac myostatin production also modestly inhibits cardiomyocyte growth under certain circumstances, as well as induces cardiac fibrosis and alterations in ventricular function. Interestingly, heart failure patients show elevated myostatin levels in their serum. To therapeutically influence skeletal muscle wasting, direct inhibition of myostatin was shown to positively impact skeletal muscle mass in heart failure, suggesting a promising strategy for the treatment of cardiac cachexia in the future.


2019 ◽  
Vol 35 (9) ◽  
pp. 1469-1478 ◽  
Author(s):  
Kate A Robinson ◽  
Luke A Baker ◽  
Matthew P M Graham-Brown ◽  
Emma L Watson

Abstract Skeletal muscle wasting is a common complication of chronic kidney disease (CKD), characterized by the loss of muscle mass, strength and function, which significantly increases the risk of morbidity and mortality in this population. Numerous complications associated with declining renal function and lifestyle activate catabolic pathways and impair muscle regeneration, resulting in substantial protein wasting. Evidence suggests that increasing skeletal muscle mass improves outcomes in CKD, making this a clinically important research focus. Despite extensive research, the pathogenesis of skeletal muscle wasting is not completely understood. It is widely recognized that microRNAs (miRNAs), a family of short non-coding RNAs, are pivotal in the regulation of skeletal muscle homoeostasis, with significant roles in regulating muscle growth, regeneration and metabolism. The abnormal expression of miRNAs in skeletal muscle during disease has been well described in cellular and animal models of muscle atrophy, and in recent years, the involvement of miRNAs in the regulation of muscle atrophy in CKD has been demonstrated. As this exciting field evolves, there is emerging evidence for the involvement of miRNAs in a beneficial crosstalk system between skeletal muscle and other organs that may potentially limit the progression of CKD. In this article, we describe the pathophysiological mechanisms of muscle wasting and explore the contribution of miRNAs to the development of muscle wasting in CKD. We also discuss advances in our understanding of miRNAs in muscle–organ crosstalk and summarize miRNA-based therapeutics currently in clinical trials.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Joerg Heineke ◽  
Mannix Auger-Messier ◽  
Michelle Sargent ◽  
Allen York ◽  
Stephen Welle ◽  
...  

Introduction: Skeletal muscle wasting during heart failure constitutes a major therapeutic challenge. The TGFβ superfamily member myostatin is a negative regulator of skeletal muscle growth. For example, elimination of myostatin (MSTN) in adult mice through an inducible Cre/lox recombination strategy has been shown to increase skeletal muscle mass by about 25%. Previous studies identified skeletal muscle and to a lesser extent cardiac and fat tissue as the source of MSTN production in the body. MSTN is produced as a precursor protein, which has been suggested to constitute the main reservoir of the protein in skeletal muscle. In mouse serum, however, MSTN is abundantly present in its mature form, which consists of the C-terminal fragment of the precursor protein. Results: We detected high levels of the mature MSTN protein (MM) in the mouse myocardium by western blotting. Interestingly, MM was significantly upregulated in the myocardium of mice subjected to long-term myocardial pressure overload (TAC, 12 weeks; protein levels: sham 100±22% vs. TAC 218±18%, p<0.01). In contrast, MM was barely detectable in mouse skeletal muscle. Immunhistochemical staining confirmed enhanced cardiomyocyte MSTN production after TAC. To determine the impact of cardiomyocyte MSTN on skeletal muscle growth during heart failure, we crossed cardiomyocyte specific Nkx2.5-Cre mice with mice in which the MSTN exon3 was flanked by loxp sites to eliminate expression of mature MSTN selectively in cardiomyocytes (CKO mice). While CKO mice did not have significant changes in skeletal muscle mass after a sham operation (e.g. quadriceps, normalized to tibia length: sham control 111±3.8 g/cm vs. sham CKO 106±4.3 g/cm), a 16% increase in skeletal muscle mass was observed in CKO mice after longterm TAC (quadriceps: TAC control 100±3.3 g/cm vs. TAC CKO 116±5.3 g/cm, p<0.05). In line with these results, mice with cardiomyocyte specific overexpression of MSTN (MSTN-Tg) showed a reduction in skeletal muscle mass (quadriceps: control 91±2.5 g/cm vs. MSTN-Tg 82±1.5 g/cm, p<0.05). Conclusion: Myocardial MSTN contributes to the development of skeletal muscle wasting in heart failure, most likely through an endocrine mechanism involving its secretion into the circulatory system.


Author(s):  
Dario Coletti

The majority of cancers are associated to cachexia, a severe form of weight loss mostly accounted for by skeletal muscle wasting. Cancer patients are often treated with chemotherapy, whose side effects are at times neglected or underestimated. Paradoxically, chemotherapy itself can induce muscle wasting with severe, cancer-independent effects on muscle homeostasis. Since muscle wasting is a primary marker of poor prognosis for cancer patients and negatively affects their quality of life, the systemic consequences of chemotherapy in this context must be fully characterized and taken into account. Ten years ago a precursor study in an animal cancer model was published in the European Journal of Translation Myology (back then, Basic and Applied Myology), highlighting that the side effects of chemotherapy include muscle wasting, possibly mediated by NF-κB activation. This paper, entitled «Chemotherapy-induced muscle wasting: association with NF-κB and cancer cachexia», is now being reprinted for the inaugural issue of the «Ejtm Seminal Paper Series». In this short review we discuss those results in the light of the most recent advances in the study of chemotherapy-induced muscle wasting.


2005 ◽  
Vol 41 (1) ◽  
pp. 173 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 588
Author(s):  
Hayden W. Hyatt ◽  
Scott K. Powers

Skeletal muscle is the most abundant tissue in the body and is required for numerous vital functions, including breathing and locomotion. Notably, deterioration of skeletal muscle mass is also highly correlated to mortality in patients suffering from chronic diseases (e.g., cancer). Numerous conditions can promote skeletal muscle wasting, including several chronic diseases, cancer chemotherapy, aging, and prolonged inactivity. Although the mechanisms responsible for this loss of muscle mass is multifactorial, mitochondrial dysfunction is predicted to be a major contributor to muscle wasting in various conditions. This systematic review will highlight the biochemical pathways that have been shown to link mitochondrial dysfunction to skeletal muscle wasting. Importantly, we will discuss the experimental evidence that connects mitochondrial dysfunction to muscle wasting in specific diseases (i.e., cancer and sepsis), aging, cancer chemotherapy, and prolonged muscle inactivity (e.g., limb immobilization). Finally, in hopes of stimulating future research, we conclude with a discussion of important future directions for research in the field of muscle wasting.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Fan Xia ◽  
Yonju Ha ◽  
Shuizhen Shi ◽  
Yi Li ◽  
Shengguo Li ◽  
...  

AbstractThe retina, as the only visually accessible tissue in the central nervous system, has attracted significant attention for evaluating it as a biomarker for neurodegenerative diseases. Yet, most of studies focus on characterizing the loss of retinal ganglion cells (RGCs) and degeneration of their axons. There is no integrated analysis addressing temporal alterations of different retinal cells in the neurovascular unit (NVU) in particular retinal vessels. Here we assessed NVU changes in two mouse models of tauopathy, P301S and P301L transgenic mice overexpressing the human tau mutated gene, and evaluated the therapeutic effects of a tau oligomer monoclonal antibody (TOMA). We found that retinal edema and breakdown of blood–retina barrier were observed at the very early stage of tauopathy. Leukocyte adhesion/infiltration, and microglial recruitment/activation were constantly increased in the retinal ganglion cell layer of tau transgenic mice at different ages, while Müller cell gliosis was only detected in relatively older tau mice. Concomitantly, the number and function of RGCs progressively decreased during aging although they were not considerably altered in the very early stage of tauopathy. Moreover, intrinsically photosensitive RGCs appeared more sensitive to tauopathy. Remarkably, TOMA treatment in young tau transgenic mice significantly attenuated vascular leakage, inflammation and RGC loss. Our data provide compelling evidence that abnormal tau accumulation can lead to pathology in the retinal NVU, and vascular alterations occur more manifest and earlier than neurodegeneration in the retina. Oligomeric tau-targeted immunotherapy has the potential to treat tau-induced retinopathies. These data suggest that retinal NVU may serve as a potential biomarker for diagnosis and staging of tauopathy as well as a platform to study the molecular mechanisms of neurodegeneration.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ying Zhu ◽  
Wen Xu ◽  
Wei Hu ◽  
Fang Wang ◽  
Yan Zhou ◽  
...  

Abstract Background Portal hypertension induced esophageal and gastric variceal bleeding is the main cause of death among patients of decompensated liver cirrhosis. Therefore, a standardized, biomarker-based test, to make an early-stage non-invasive risk assessment of portal hypertension, is highly desirable. However, no fit-for-purpose biomarkers have yet been identified. Methods We conducted a pilot study consisting of 5 portal hypertensive gastropathy (PHG) patients and 5 normal controls, sampling the gastric mucosa of normal controls and PHG patients before and after endoscopic cyanoacrylate injection, using label-free quantitative (LFQ) mass spectrometry, to identify potential biomarker candidates in gastric mucosa from PHG patients and normal controls. Then we further used parallel reaction monitoring (PRM) to verify the abundance of the targeted protein. Results LFQ analyses identified 423 significantly differentially expressed proteins. 17 proteins that significantly elevated in the gastric mucosa of PHG patients were further validated using PRM. Conclusions This is the first application of an LFQ-PRM workflow to identify and validate PHG–specific biomarkers in patient gastric mucosa samples. Our findings lay the foundation for comprehending the molecular mechanisms of PHG pathogenesis, and provide potential applications for useful biomarkers in early diagnosis and treatment. Trial registration and ethics approval: Trial registration was completed (ChiCTR2000029840) on February 25, 2020. Ethics Approvals were completed on July 17, 2017 (NYSZYYEC20180003) and February 15, 2020 (NYSZYYEC20200005).


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