scholarly journals PGC-1α in the myofibers regulates the balance between myogenic and adipogenic progenitors affecting muscle regeneration

2021 ◽  
Author(s):  
Marc Beltrà ◽  
Fabrizio Pin ◽  
Domiziana Costamagna ◽  
Robin Duelen ◽  
Alessandra Renzini ◽  
...  

Skeletal muscle repair is accomplished by satellite cells (MuSC) in cooperation with interstitial stromal cells (ISCs). So far, the relationship between the function of these cells and the metabolic state of myofibers remains unclear. The present study reports alterations in the proportion of both MuSCs and adipogenesis regulators (Aregs) induced by overexpression of peroxisome proliferator-activated receptor gamma coactivator 1–alpha (PGC–1α) in the myofibers (MCK–PGC–1α mice). Although PGC-1α–driven increase of MuSCs does not accelerate muscle regeneration, myogenic progenitors isolated from MCK–PGC–1α mice and transplanted into intact and regenerating muscles are more prone to fuse with recipient myofibers than those derived from WT donors. Moreover, both young and aged MCK-PGC-1α animals show reduced perilipin-positive areas when challenged with an adipogenic stimulus, demonstrating low propensity to accumulate adipocytes within the muscle. These results provide new insights on the role played by PGC–1α in promoting myogenesis and hindering adipogenesis in the skeletal muscle.

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1479
Author(s):  
Karolina Archacka ◽  
Joanna Bem ◽  
Edyta Brzoska ◽  
Areta M. Czerwinska ◽  
Iwona Grabowska ◽  
...  

Under physiological conditions skeletal muscle regeneration depends on the satellite cells. After injury these cells become activated, proliferate, and differentiate into myofibers reconstructing damaged tissue. Under pathological conditions satellite cells are not sufficient to support regeneration. For this reason, other cells are sought to be used in cell therapies, and different factors are tested as a tool to improve the regenerative potential of such cells. Many studies are conducted using animal cells, omitting the necessity to learn about human cells and compare them to animal ones. Here, we analyze and compare the impact of IL-4 and SDF-1, factors chosen by us on the basis of their ability to support myogenic differentiation and cell migration, at mouse and human adipose tissue-derived stromal cells (ADSCs). Importantly, we documented that mouse and human ADSCs differ in certain reactions to IL-4 and SDF-1. In general, the selected factors impacted transcriptome of ADSCs and improved migration and fusion ability of cells in vitro. In vivo, after transplantation into injured muscles, mouse ADSCs more eagerly participated in new myofiber formation than the human ones. However, regardless of the origin, ADSCs alleviated immune response and supported muscle reconstruction, and cytokine treatment enhanced these effects. Thus, we documented that the presence of ADSCs improves skeletal muscle regeneration and this influence could be increased by cell pretreatment with IL-4 and SDF-1.


2018 ◽  
Vol 315 (5) ◽  
pp. C714-C721 ◽  
Author(s):  
Irena A. Rebalka ◽  
Cynthia M. F. Monaco ◽  
Nina E. Varah ◽  
Thorsten Berger ◽  
Donna M. D’souza ◽  
...  

Lipocalin-2 (LCN2) is an adipokine previously described for its contribution to numerous processes, including innate immunity and energy metabolism. LCN2 has also been demonstrated to be an extracellular matrix (ECM) regulator through its association with the ECM protease matrix metalloproteinase-9 (MMP-9). With the global rise in obesity and the associated comorbidities related to increasing adiposity, it is imperative to gain an understanding of the cross talk between adipose tissue and other metabolic tissues, such as skeletal muscle. Given the function of LCN2 on the ECM in other tissues and the importance of matrix remodeling in skeletal muscle regeneration, we examined the localization and expression of LCN2 in uninjured and regenerating wild-type skeletal muscle and assessed the impact of LCN2 deletion (LCN2−/−) on skeletal muscle repair following cardiotoxin injury. Though LCN2 was minimally present in uninjured skeletal muscle, its expression was increased significantly at 1 and 2 days postinjury, with expression present in Pax7-positive satellite cells. Although satellite cell content was unchanged, the ability of quiescent satellite cells to become activated was significantly impaired in LCN2−/− skeletal muscles. Skeletal muscle regeneration was also significantly compromised as evidenced by decreased embryonic myosin heavy chain expression and smaller regenerating myofiber areas. Consistent with a role for LCN2 in MMP-9 regulation, regenerating muscle also displayed a significant increase in fibrosis and lower ( P = 0.07) MMP-9 activity in LCN2−/− mice at 2 days postinjury. These data highlight a novel role for LCN2 in muscle regeneration and suggest that changes in adipokine expression can significantly impact skeletal muscle repair.


Author(s):  
Dalia Medhat ◽  
Mona A. El-Bana ◽  
Sherien M. El-Daly ◽  
Magdi N. Ashour ◽  
Tahany R. Elias ◽  
...  

Abstract Objective To evaluate the influence of irisin on the experimental paradigm of non-alcoholic fatty liver (NAFL) as a part of MetS cluster. Methods Forty male albino rats were divided into four groups; normal control, standard diet + irisin, high carbohydrate and fat diet (HCHF), and HCHF + irisin. After the experimental period, levels of fasting blood sugar (FBS), insulin, lipid profile, kidney functions, salusin-alpha (Sal-α), adropin, and retinol-binding protein-4 (RBP-4) were evaluated. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1α) expression in skeletal muscle was evaluated by quantitative real-time PCR. Aorta, liver, pancreas, and skeletal muscle tissue samples were prepared for histopathological examination. Results Rats administrated HCHF showed elevated levels of FBS, lipid profile, kidney functions, RBP-4, and downregulation of PGC-1α expression along with a decline in levels of insulin, Sal-α, and adropin while administration of irisin significantly attenuated these levels. Conclusions Irisin as based therapy could emerge as a new line of treatment against MetS and its related diseases.


Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 807
Author(s):  
Silvia Ravalli ◽  
Concetta Federico ◽  
Giovanni Lauretta ◽  
Salvatore Saccone ◽  
Elisabetta Pricoco ◽  
...  

Skeletal muscle atrophy, resulting from states of hypokinesis or immobilization, leads to morphological, metabolic, and functional changes within the muscle tissue, a large variety of which are supported by the stromal cells populating the interstitium. Telocytes represent a recently discovered population of stromal cells, which has been increasingly identified in several human organs and appears to participate in sustaining cross-talk, promoting regenerative mechanisms and supporting differentiation of local stem cell niche. The aim of this morphologic study was to investigate the presence of Telocytes in the tibialis anterior muscle of healthy rats undergoing an endurance training protocol for either 4 weeks or 16 weeks compared to sedentary rats. Histomorphometric analysis of muscle fibers diameter revealed muscle atrophy in sedentary rats. Telocytes were identified by double-positive immunofluorescence staining for CD34/CD117 and CD34/vimentin. The results showed that Telocytes were significantly reduced in sedentary rats at 16 weeks, while rats subjected to regular exercise maintained a stable Telocytes population after 16 weeks. Understanding of the relationship between Telocytes and exercise offers new chances in the field of regenerative medicine, suggesting possible triggers for Telocytes in sarcopenia and other musculoskeletal disorders, promoting adapted physical activity and rehabilitation programmes in clinical practice.


2017 ◽  
Vol 312 (5) ◽  
pp. E394-E406 ◽  
Author(s):  
Samuel Lee ◽  
Teresa C. Leone ◽  
Lisa Rogosa ◽  
John Rumsey ◽  
Julio Ayala ◽  
...  

Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α and -1β serve as master transcriptional regulators of muscle mitochondrial functional capacity and are capable of enhancing muscle endurance when overexpressed in mice. We sought to determine whether muscle-specific transgenic overexpression of PGC-1β affects the detraining response following endurance training. First, we established and validated a mouse exercise-training-detraining protocol. Second, using multiple physiological and gene expression end points, we found that PGC-1β overexpression in skeletal muscle of sedentary mice fully recapitulated the training response. Lastly, PGC-1β overexpression during the detraining period resulted in partial prevention of the detraining response. Specifically, an increase in the plateau at which O2 uptake (V̇o2) did not change from baseline with increasing treadmill speed [peak V̇o2 (ΔV̇o2max)] was maintained in trained mice with PGC-1β overexpression in muscle 6 wk after cessation of training. However, other detraining responses, including changes in running performance and in situ half relaxation time (a measure of contractility), were not affected by PGC-1β overexpression. We conclude that while activation of muscle PGC-1β is sufficient to drive the complete endurance phenotype in sedentary mice, it only partially prevents the detraining response following exercise training, suggesting that the process of endurance detraining involves mechanisms beyond the reversal of muscle autonomous mechanisms involved in endurance fitness. In addition, the protocol described here should be useful for assessing early-stage proof-of-concept interventions in preclinical models of muscle disuse atrophy.


Endocrinology ◽  
2013 ◽  
Vol 154 (12) ◽  
pp. 4803-4813 ◽  
Author(s):  
Dan I. Lebovic ◽  
Shahryar K. Kavoussi ◽  
JeHoon Lee ◽  
Sakhila K. Banu ◽  
Joe A. Arosh

Endometriosis is a chronic inflammatory disease of reproductive age women leading to chronic pelvic pain and infertility. Current antiestrogen therapies are temporizing measures, and endometriosis often recurs. Potential nonestrogenic or nonsteroidal targets are needed for treating endometriosis. Peroxisome proliferator-activated receptor (PPAR)γ, a nuclear receptor, is activated by thiazolidinediones (TZDs). In experimental endometriosis, TZDs inhibit growth of endometriosis. Clinical data suggest potential use of TZDs for treating pain and fertility concurrently in endometriosis patients. Study objectives were to 1) determine the effects of PPARγ action on growth and survival of human endometriotic epithelial and stromal cells and 2) identify the underlying molecular links between PPARγ activation and cell cycle regulation, apoptosis, estrogen biosynthesis, and prostaglandin E2 biosynthesis and signaling in human endometriotic epithelial and stromal cells. Results indicate that activation of PPARγ by TZD ciglitazone 1) inhibits growth of endometriotic epithelial cells 12Z up to 35% and growth of endometriotic stromal cells 22B up to 70% through altered cell cycle regulation and intrinsic apoptosis, 2) decreases expression of PGE2 receptors (EP)2 and EP4 mRNAs in 12Z and 22B cells, and 3) inhibits expression and function of P450 aromatase mRNA and protein and estrone production in 12Z and 22B cells through EP2 and EP4 in a stromal-epithelial cell-specific manner. Collectively, these results indicate that PGE2 receptors EP2 and EP4 mediate actions of PPARγ by incorporating multiple cell signaling pathways. Activation of PPARγ combined with inhibition of EP2 and EP4 may emerge as novel nonsteroidal therapeutic targets for endometriosis-associated pain and infertility, if clinically proven safe and efficacious.


1966 ◽  
Vol 53 (7) ◽  
pp. 638-642 ◽  
Author(s):  
J. C. T. Church ◽  
R. F. X. Noronha ◽  
D. B. Allbrook

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