scholarly journals Simvastatin Impairs the Inflammatory and Repair Phases of the Postinjury Skeletal Muscle Regeneration

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Iwona Otrocka-Domagała ◽  
Katarzyna Paździor-Czapula ◽  
Tomasz Maślanka

Background. Recent clinical data have suggested that the chronic use of high-lipophilic statins impairs the regenerative capacity of skeletal muscle. Because this activity of statins is poorly understood, we aimed to investigate the effect of simvastatin (SIM) on postinjury myofibre regeneration. Methods. The porcine model was used in this study. The animals were divided into two groups: nontreated (control; n=24) and SIM-treated (40 mg/day; n=24). On the 15th day (day 0) of the experiment, a bupivacaine hydrochloride- (BPVC-) induced muscle injury was established, and the animals were sacrificed in the following days after muscle injury. The degree of regeneration was assessed based on histopathological and immunohistochemical examinations. The presence and degree of extravasation, necrosis, and inflammation in the inflammatory phase were assessed, whereas the repair phase was evaluated based on the numbers of muscle precursor cells (MPCs), myotube and young myofibres. Results. In the inflammatory phase, SIM increased the distribution and prolonged the period of extravasation, prolonged the duration of necrosis, and prolonged and enhanced the infiltration of inflammatory cells. In the repair phase, SIM delayed and prolonged the activity of MPCs, delayed myotube formation, and delayed and decreased the formation of young myofibres. Our results indicated that SIM did not improve blood vessel stabilization at the site of the injury, did not exert an anti-inflammatory effect, prolonged and enhanced the inflammatory response, and impaired MPC activity, differentiation, and fusion. Moreover, SIM appeared to reduce M1 macrophage activity, resulting in slower removal of necrotic debris and sustained necrosis. Conclusion. This study shows that SIM negatively affects the inflammatory and repair phases of the postinjury muscle regeneration. These findings are unique, strengthen the available knowledge on the side effects of SIM, and provide evidence showing that statin therapy is associated with an increased risk of impairment of the regenerative capacity of muscle.

2021 ◽  
Author(s):  
Kentaro Fukuda ◽  
Taisuke Kuroda ◽  
Norihisa Tamura ◽  
Hiroshi Mita ◽  
Hirofumi Miyata ◽  
...  

2021 ◽  
Author(s):  
David Ollitrault ◽  
Valentina Buffa ◽  
Rosamaria Correra ◽  
Angeliqua Sayed ◽  
Benedicte Hoareau ◽  
...  

Skeletal muscle injury results in a disruption of the muscle bed vascular network. A local source of vascular progenitors during muscle regeneration has not been clearly identified. Fibroadipogenic progenitors (FAPs) are required for proper regeneration, however they can also directly contribute to fibrotic and fatty infiltration in response to chronic muscle injury and muscle disease. We show here that acute muscle injury leads to hypoxia and glucose deprivation, triggering FAP proliferation and differentiation into endothelial cells in vitro and in vivo. In response to glucose deprivation, FAPs down regulate fibrotic and fat associated genes and acquire an endothelial cell fate, which is dependent upon mTORC2-HIF2a-eNOS pathway. These findings bring new insights into the mechanisms of vascular regeneration during muscle regeneration and define a highly plastic resident progenitor population that responds to oxygen/glucose-deprivation induced cell stress by promoting an endothelial cell fate.


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Xiaoguang Liu ◽  
Weihua Xiao ◽  
Lifang Zhen ◽  
Yongzhan Zhou ◽  
Jian Shou

Objective Skeletal muscle contusion is one of the most common muscle injury in sports medicine and traumatology. Bone marrow mesenchymal stem cells (BMSCs) transplantation is a promising strategy for muscle regeneration. However, the roles of BMSCs, especially the mechanisms involved, in the regeneration of contused skeletal muscle are still not fully recognized. The aim of the study is to evaluate the potential of BMSCs transplantation for muscle regeneration and mechanisms involved after contusion. Methods Ninety-nine C57BL/6J mice were divided into three groups: control group (n=11), muscle contusion and BMSCs treated group (n=44), muscle contusion and sham treated group (n=44). BMSCs were immediately transplanted into gastrocnemius muscles (GMs) following direct contusion. At different time points (3, 6, 12 and 24 days) post-injury, the animals were killed and then GMs were harvested. Morphological and gene expression analyses were used to elevate the effect of BMSCs transplantation and mechanisms involved. Results The results indicate that BMSCs transplantation impairs muscle regeneration, as well as more fibrotic scar formation after skeletal muscle contusion. Furthermore, macrophages, inflammatory cytokines, chemokines, matrix metalloproteinases and oxidative stress related enzymes were significantly increased after BMSCs transplantation. These results suggest that BMSCs transplantation impairs skeletal muscle regeneration and that macrophages, inflammatory cytokines, chemokines, matrix metalloproteinases and oxidative stress related enzymes may be involved in the process. Conclusions BMSCs transplantation aggravates inflammation, oxidative stress and fibrosis, and impairs skeletal muscle regeneration, which shed new light on the role of BMSCs in regenerative medicine and cautions the application of BMSCs for muscle injury.


2007 ◽  
Vol 179 (2) ◽  
pp. 305-319 ◽  
Author(s):  
Daniela Deponti ◽  
Stéphanie François ◽  
Silvia Baesso ◽  
Clara Sciorati ◽  
Anna Innocenzi ◽  
...  

Regeneration of muscle fibers that are lost during pathological muscle degeneration or after injuries is sustained by the production of new myofibers. An important cell type involved in muscle regeneration is the satellite cell. Necdin is a protein expressed in satellite cell–derived myogenic precursors during perinatal growth. However, its function in myogenesis is not known. We compare transgenic mice that overexpress necdin in skeletal muscle with both wild-type and necdin null mice. After muscle injury the necdin null mice show a considerable defect in muscle healing, whereas mice that overexpress necdin show a substantial increase in myofiber regeneration. We also find that in muscle, necdin increases myogenin expression, accelerates differentiation, and counteracts myoblast apoptosis. Collectively, these data clarify the function and mechanism of necdin in skeletal muscle and show the importance of necdin in muscle regeneration.


2004 ◽  
Vol 287 (2) ◽  
pp. C475-C483 ◽  
Author(s):  
Brenda A. Bondesen ◽  
Stephen T. Mills ◽  
Kristy M. Kegley ◽  
Grace K. Pavlath

Skeletal muscle regeneration comprises several overlapping cellular processes, including inflammation and myogenesis. Prostaglandins (PGs) may regulate muscle regeneration, because they modulate inflammation and are involved in various stages of myogenesis in vitro. PG synthesis is catalyzed by different isoforms of cyclooxygenase (COX), which are inhibited by nonsteroidal anti-inflammatory drugs. Although experiments employing nonsteroidal anti-inflammatory drugs have implicated PGs in tissue repair, how PGs regulate muscle regeneration remains unclear, and the potentially distinct roles of different COX isoforms have not been investigated. To address these questions, a localized freeze injury was induced in the tibialis anterior muscles of mice chronically treated with either a COX-1- or COX-2-selective inhibitor (SC-560 and SC-236, respectively), starting before injury. The size of regenerating myofibers was analyzed at time points up to 5 wk after injury and found to be decreased by SC-236 and in COX-2−/− muscles, but unaffected by SC-560. In contrast, SC-236 had no effect on myofiber growth when administered starting 7 days after injury. The attenuation of myofiber growth by SC-236 treatment and in COX-2−/− muscles is associated with decreases in the number of myoblasts and intramuscular inflammatory cells at early times after injury. Together, these data suggest that COX-2-dependent PG synthesis is required during early stages of muscle regeneration and thus raise caution about the use of COX-2-selective inhibitors in patients with muscle injury or disease.


2016 ◽  
Vol 4 ◽  
pp. 1-10 ◽  
Author(s):  
Hongxue Shi ◽  
Haohuang Xie ◽  
Yan Zhao ◽  
Cai Lin ◽  
Feifei Cui ◽  
...  

Abstract Background Pressure ulcers (PUs) are a major clinical problem that constitutes a tremendous economic burden on healthcare systems. Deep tissue injury (DTI) is a unique serious type of pressure ulcer that arises in skeletal muscle tissue. DTI arises in part because skeletal muscle tissues are more susceptible than skin to external compression. Unfortunately, few effective therapies are currently available for muscle injury. Basic fibroblast growth factor (bFGF), a potent mitogen and survival factor for various cells, plays a crucial role in the regulation of muscle development and homeostasis. The main purpose of this study was to test whether local administration of bFGF could accelerate muscle regeneration in a rat DTI model. Methods Male Sprague Dawley (SD) rats (age 12 weeks) were individually housed in plastic cages and a DTI PU model was induced according to methods described before. Animals were randomly divided into three groups: a normal group, a PU group treated with saline, and a PU group treated with bFGF (10 μg/0.1 ml) subcutaneously near the wound. Results We found that application of bFGF accelerated the rate of wound closure and promoted cell proliferation and tissue angiogenesis. In addition, compared to saline administration, bFGF treatment prevented collagen deposition, a measure of fibrosis, and up-regulated the myogenic marker proteins MyHC and myogenin, suggesting bFGF promoted injured muscle regeneration. Moreover, bFGF treatment increased levels of myogenesis-related proteins p-Akt and p-mTOR. Conclusions Our findings show that bFGF accelerated injured skeletal muscle regeneration through activation of the PI3K/Akt/mTOR signaling pathway and suggest that administration of bFGF is a potential therapeutic strategy for the treatment of skeletal muscle injury in PUs.


2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Junio Dort ◽  
Paul Fabre ◽  
Thomas Molina ◽  
Nicolas A. Dumont

Muscle regeneration is a closely regulated process that involves a variety of cell types such as satellite cells, myofibers, fibroadipogenic progenitors, endothelial cells, and inflammatory cells. Among these different cell types, macrophages emerged as a central actor coordinating the different cellular interactions and biological processes. Particularly, the transition of macrophages from their proinflammatory to their anti-inflammatory phenotype was shown to regulate inflammation, myogenesis, fibrosis, vascularization, and return to homeostasis. On the other hand, deregulation of macrophage accumulation or polarization in chronic degenerative muscle disorders was shown to impair muscle regeneration. Considering the key roles of macrophages in skeletal muscle, they represent an attractive target for new therapeutic approaches aiming at mitigating various muscle disorders. This review aims at summarizing the novel insights into macrophage heterogeneity, plasticity, and functions in skeletal muscle homeostasis, regeneration, and disease.


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