scholarly journals The role of Pitx2 and Pitx3 in muscle stem cells gives new insights into P38α MAP kinase and redox regulation of muscle regeneration

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Aurore L'honoré ◽  
Pierre-Henri Commère ◽  
Elisa Negroni ◽  
Giorgia Pallafacchina ◽  
Bertrand Friguet ◽  
...  

Skeletal muscle regeneration depends on satellite cells. After injury these muscle stem cells exit quiescence, proliferate and differentiate to regenerate damaged fibres. We show that this progression is accompanied by metabolic changes leading to increased production of reactive oxygen species (ROS). Using Pitx2/3 single and double mutant mice that provide genetic models of deregulated redox states, we demonstrate that moderate overproduction of ROS results in premature differentiation of satellite cells while high levels lead to their senescence and regenerative failure. Using the ROS scavenger, N-Acetyl-Cysteine (NAC), in primary cultures we show that a physiological increase in ROS is required for satellite cells to exit the cell cycle and initiate differentiation through the redox activation of p38α MAP kinase. Subjecting cultured satellite cells to transient inhibition of P38α MAP kinase in conjunction with NAC treatment leads to their rapid expansion, with striking improvement of their regenerative potential in grafting experiments.

2018 ◽  
Author(s):  
Aurore L'honoré ◽  
Pierre-Henri Commère ◽  
Elisa Negroni ◽  
Giorgia Pallafacchina ◽  
Bertrand Friguet ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Manuel Scimeca ◽  
Elena Bonanno ◽  
Eleonora Piccirilli ◽  
Jacopo Baldi ◽  
Alessandro Mauriello ◽  
...  

Age-related bone diseases, such as osteoarthritis and osteoporosis, are strongly associated with sarcopenia and muscle fiber atrophy. In this study, we analyzed muscle biopsies in order to demonstrate that, in osteoarthritis patients, both osteophytes formation and regenerative properties of muscle stem cells are related to the same factors. In particular, thanks to immunohistochemistry, transmission electron microscopy, and immunogold labeling we investigated the role of BMP-2 in muscle stem cells activity. In patients with osteoarthritis both immunohistochemistry and transmission electron microscopy allowed us to note a higher number of CD44 positive satellite muscle cells forming syncytium. Moreover, the perinuclear and cytoplasmic expression of BMP-2 assessed byin situmolecular characterization of satellite cells syncytia suggest a very strict correlation between BMP-2 expression and muscle regeneration capability. Summing up, the higher BMP-2 expression in osteoarthritic patients could explain the increased bone mineral density as well as decreased muscle atrophy in osteoarthrosic patients. In conclusion, our results suggest that the control of physiological BMP-2 balance between bone and muscle tissues may be considered as a potential pharmacological target in bone-muscle related pathology.


2018 ◽  
Vol 19 (7) ◽  
pp. 2044 ◽  
Author(s):  
Gabriele Dammone ◽  
Sonia Karaz ◽  
Laura Lukjanenko ◽  
Carine Winkler ◽  
Federico Sizzano ◽  
...  

Skeletal muscle is a regenerative tissue which can repair damaged myofibers through the activation of tissue-resident muscle stem cells (MuSCs). Many muscle diseases with impaired regeneration cause excessive adipose tissue accumulation in muscle, alter the myogenic fate of MuSCs, and deregulate the cross-talk between MuSCs and fibro/adipogenic progenitors (FAPs), a bi-potent cell population which supports myogenesis and controls intra-muscular fibrosis and adipocyte formation. In order to better characterize the interaction between adipogenesis and myogenesis, we studied muscle regeneration and MuSC function in whole body Pparg null mice generated by epiblast-specific Cre/lox deletion (PpargΔ/Δ). We demonstrate that deletion of PPARγ completely abolishes ectopic muscle adipogenesis during regeneration and impairs MuSC expansion and myogenesis after injury. Ex vivo assays revealed that perturbed myogenesis in PpargΔ/Δ mice does not primarily result from intrinsic defects of MuSCs or from perturbed myogenic support from FAPs. The immune transition from a pro- to anti-inflammatory MuSC niche during regeneration is perturbed in PpargΔ/Δ mice and suggests that PPARγ signaling in macrophages can interact with ectopic adipogenesis and influence muscle regeneration. Altogether, our study demonstrates that a PPARγ-dependent adipogenic response regulates muscle fat infiltration during regeneration and that PPARγ is required for MuSC function and efficient muscle repair.


Open Biology ◽  
2021 ◽  
Vol 11 (12) ◽  
Author(s):  
Thomas Molina ◽  
Paul Fabre ◽  
Nicolas A. Dumont

Skeletal muscle possesses a remarkable regenerative capacity that relies on the activity of muscle stem cells, also known as satellite cells. The presence of non-myogenic cells also plays a key role in the coordination of skeletal muscle regeneration. Particularly, fibro-adipogenic progenitors (FAPs) emerged as master regulators of muscle stem cell function and skeletal muscle regeneration. This population of muscle resident mesenchymal stromal cells has been initially characterized based on its bi-potent ability to differentiate into fibroblasts or adipocytes. New technologies such as single-cell RNAseq revealed the cellular heterogeneity of FAPs and their complex regulatory network during muscle regeneration. In acute injury, FAPs rapidly enter the cell cycle and secrete trophic factors that support the myogenic activity of muscle stem cells. Conversely, deregulation of FAP cell activity is associated with the accumulation of fibrofatty tissue in pathological conditions such as muscular dystrophies and ageing. Considering their central role in skeletal muscle pathophysiology, the regulatory mechanisms of FAPs and their cellular and molecular crosstalk with muscle stem cells are highly investigated in the field. In this review, we summarize the current knowledge on FAP cell characteristics, heterogeneity and the cellular crosstalk during skeletal muscle homeostasis and regeneration. We further describe their role in muscular disorders, as well as different therapeutic strategies targeting these cells to restore muscle regeneration.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 744
Author(s):  
Matthew Borok ◽  
Nathalie Didier ◽  
Francesca Gattazzo ◽  
Teoman Ozturk ◽  
Aurelien Corneau ◽  
...  

Background: Skeletal muscle is one of the only mammalian tissues capable of rapid and efficient regeneration after trauma or in pathological conditions. Skeletal muscle regeneration is driven by the muscle satellite cells, the stem cell population in interaction with their niche. Upon injury, muscle fibers undergo necrosis and muscle stem cells activate, proliferate and fuse to form new myofibers. In addition to myogenic cell populations, interaction with other cell types such as inflammatory cells, mesenchymal (fibroadipogenic progenitors—FAPs, pericytes) and vascular (endothelial) lineages are important for efficient muscle repair. While the role of the distinct populations involved in skeletal muscle regeneration is well characterized, the quantitative changes in the muscle stem cell and niche during the regeneration process remain poorly characterized. Methods: We have used mass cytometry to follow the main muscle cell types (muscle stem cells, vascular, mesenchymal and immune cell lineages) during early activation and over the course of muscle regeneration at D0, D2, D5 and D7 compared with uninjured muscles. Results: Early activation induces a number of rapid changes in the proteome of multiple cell types. Following the induction of damage, we observe a drastic loss of myogenic, vascular and mesenchymal cell lineages while immune cells invade the damaged tissue to clear debris and promote muscle repair. Immune cells constitute up to 80% of the mononuclear cells 5 days post-injury. We show that muscle stem cells are quickly activated in order to form new myofibers and reconstitute the quiescent muscle stem cell pool. In addition, our study provides a quantitative analysis of the various myogenic populations during muscle repair. Conclusions: We have developed a mass cytometry panel to investigate the dynamic nature of muscle regeneration at a single-cell level. Using our panel, we have identified early changes in the proteome of stressed satellite and niche cells. We have also quantified changes in the major cell types of skeletal muscle during regeneration and analyzed myogenic transcription factor expression in satellite cells throughout this process. Our results highlight the progressive dynamic shifts in cell populations and the distinct states of muscle stem cells adopted during skeletal muscle regeneration. Our findings give a deeper understanding of the cellular and molecular aspects of muscle regeneration.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Emilie Barruet ◽  
Steven Garcia ◽  
Stanley Tamaki ◽  
Blanca M Morales ◽  
Jake Wu ◽  
...  

Abstract Developing optimal strategies for skeletal muscle regeneration and repair requires a detailed understanding of how these processes are regulated. The number of primary human satellite cells that can be obtained is usually extremely low, and may be impaired in disease of impaired skeletal muscle repair. One such condition is fibrodysplasia ossificans progressiva (FOP), a progressive disease characterized by massive heterotopic ossification in skeletal muscles and aberrant skeletal muscle repair after injury. FOP patients have activating mutations in the Activin A Type I receptor (ACVR1), a bone morphogenetic protein (BMP) receptor. Our overall hypothesis is that activated ACVR1 signaling caused by the ACVR1 R206H mutation incites inappropriate activation of human muscle stem cells (satellite cells, PAX7 expressing cells), causing loss of muscle cell fate and aberrant muscle repair. Since human satellite cells are difficult to obtain from live tissue donors, and injury can trigger heterotopic ossification, we created human induced pluripotent stem cell (iPSC)-derived muscle stem cells (iMuSCs) from FOP and control iPSC lines. We found that control and FOP iPSCs can differentiate into PAX7+ cells with high efficiency. Control and FOP iMuSCs can regenerate injured mouse muscle and form new human fibers, but both showed few PAX7 cells after transplant. Single cell RNA sequencing showed cell heterogeneity, and specific subsets of PAX7+ cells. FOP iMuSCs showed a chondrogenic/osteogenic signature (e.g COL1A1, DCN, OGN) with higher p38 pathway signaling activity. Skeletal muscle samples from autopsies of patients with FOP also showed increased expression of COL1A1. Additionally, we found that primary human FOP satellite cells can engraft and regenerate injured muscle, but with lower efficiency than control satellite cells. These studies used a novel iMuSC strategy to elucidate how increased ACVR1 activity affects human satellite cells function, and compare these iMuSCs to primary human satellite cells. These approaches will be useful to identify new therapeutic targets for conditions affecting skeletal muscle, and will improve our understanding of how muscle and bone interact in development and disease pathophysiology.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Karolina Archacka ◽  
Iwona Grabowska ◽  
Bartosz Mierzejewski ◽  
Joanna Graffstein ◽  
Alicja Górzyńska ◽  
...  

Abstract Background The skeletal muscle reconstruction occurs thanks to unipotent stem cells, i.e., satellite cells. The satellite cells remain quiescent and localized between myofiber sarcolemma and basal lamina. They are activated in response to muscle injury, proliferate, differentiate into myoblasts, and recreate myofibers. The stem and progenitor cells support skeletal muscle regeneration, which could be disturbed by extensive damage, sarcopenia, cachexia, or genetic diseases like dystrophy. Many lines of evidence showed that the level of oxygen regulates the course of cell proliferation and differentiation. Methods In the present study, we analyzed hypoxia impact on human and pig bone marrow-derived mesenchymal stromal cell (MSC) and mouse myoblast proliferation, differentiation, and fusion. Moreover, the influence of the transplantation of human bone marrow-derived MSCs cultured under hypoxic conditions on skeletal muscle regeneration was studied. Results We showed that bone marrow-derived MSCs increased VEGF expression and improved myogenesis under hypoxic conditions in vitro. Transplantation of hypoxia preconditioned bone marrow-derived MSCs into injured muscles resulted in the improved cell engraftment and formation of new vessels. Conclusions We suggested that SDF-1 and VEGF secreted by hypoxia preconditioned bone marrow-derived MSCs played an essential role in cell engraftment and angiogenesis. Importantly, hypoxia preconditioned bone marrow-derived MSCs more efficiently engrafted injured muscles; however, they did not undergo myogenic differentiation.


Sign in / Sign up

Export Citation Format

Share Document