scholarly journals A randomized placebo-controlled clinical trial of Nicotinamide Riboside and Pterostilbene supplementation in experimental muscle injury in elderly subjects

Author(s):  
Jonas Brorson Jensen ◽  
Ole Lindgaard Dollerup ◽  
Andreas Buch Moeller ◽  
Tine Borum Billeskov ◽  
Emilie Dalbram ◽  
...  

Background Maintenance and regeneration of functional skeletal muscle are dependent on a sufficient pool of muscle stem cells (MuSCs). During ageing there is a functional decline in this cellular pool which influences the regenerative capacity of skeletal muscle. Preclinical evidence have suggested that Nicotinamide Riboside (NR) and Pterostilbene (PT) can improve muscle regeneration e.g. by increasing MuSC function. The objective of the present study was to investigate if NRPT supplementation promotes skeletal muscle regeneration after muscle injury in elderly humans by improved recruitment of MuSCs. Methods In a randomized, double-blinded, placebo-controlled trial, 32 elderly men and women (55-80 yr) received daily supplementation with either NRPT (1000 mg NR + 200 mg PT) or matched placebo. Two weeks after initiation of supplementation, a skeletal muscle injury was applied in the vastus lateralis part of the quadriceps femoris muscle by electrically induced eccentric muscle work in a dynamometer. Skeletal muscle biopsies were obtained pre, 2h, 2, 8, and 30 days post injury. The main outcome of the study was change in MuSC content 8 days post injury. Results 31 enrolled subjects completed the entire protocol. The muscle work induced a substantial skeletal muscle injury in the study participants and was associated with release of myoglobin and creatine kinase, muscle soreness, tissue edema, and a decrease in muscle strength. MuSC content increased by 107% 8 days post injury (p= 0.0002) but with no effect of NRPT supplementation (p=0.58 for supplementation effect). MuSC proliferation and cell size revealed a large demand for recruitment post injury but was not affected by NRPT. Furthermore, histological analyses of muscle fiber area, internal nuclei and embryonic Myosin Heavy Chain showed no effect of NRPT supplementation. Conclusion Daily supplementation with 1000 mg NR + 200 mg PT is safe but does not improve recruitment of the MuSC pool or other measures of muscle recovery in response to injury or subsequent regeneration in elderly subjects.

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ya Tan ◽  
Linyuan Shen ◽  
Mailin Gan ◽  
Yuan Fan ◽  
Xiao Cheng ◽  
...  

Skeletal muscle is the most abundant and a highly plastic tissue of the mammals, especially when it comes to regenerate after trauma, but there is limited information about the mechanism of muscle repair and its regeneration. In the present study, we found that miR-204 is downregulated after skeletal muscle injury. In vitro experiments showed that over-expression of miR-204 by transfecting with miR-204 mimics suppressed C2C12 cell proliferation, migration, and blocked subsequent differentiation, whereas inhibition of miR-204 by transfecting with miR-204 inhibitor showed the converse effects. Furthermore, through the dual luciferase reporter system, we demonstrated that miR-204 can target the 3’UTR regions of Pax7, IGF1, and Mef2c and inhibit their expression. Taken together, our results suggest that Pax7, IGF1, and Mef2c are the target genes of miR-204 in the process of myoblasts proliferation, cell migration, and differentiation, respectively, and may contribute to mouse skeletal muscle regeneration. Our results may provide new ideas and references for the skeletal muscle study and may also provide therapeutic strategies of skeletal muscle injury.


2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Yuantong Liu ◽  
Yue Shang ◽  
Zihan Yan ◽  
Hao Li ◽  
Zhen Wang ◽  
...  

Abstract Adult skeletal muscle regeneration after injury depends on normal myoblast function. However, the intrinsic mechanisms for the control of myoblast behaviors are not well defined. Herein, we identified Pim1 kinase as a novel positive regulator of myoblast behaviors in vitro and muscle regeneration in vivo. Specifically, knockdown of Pim1 significantly restrains the proliferation and accelerates the apoptosis of myoblasts in vitro, indicating that Pim1 is critical for myoblast survival and amplification. Meanwhile, we found that Pim1 kinase is increased and translocated from cytoplasm into nucleus during myogenic differentiation. By using Pim1 kinase inhibitor, we proved that inhibition of Pim1 activity prevents myoblast differentiation and fusion, suggesting the necessity of Pim1 kinase activity for proper myogenesis. Mechanistic studies demonstrated that Pim1 kinase interacts with myogenic regulator MyoD and controls its transcriptional activity, inducing the expression of muscle-specific genes, which consequently promotes myogenic differentiation. Additionally, in skeletal muscle injury mouse model, deletion of Pim1 hinders the regeneration of muscle fibers and the recovery of muscle strength. Taken together, our study provides a potential target for the manipulation of myoblast behaviors in vitro and the myoblast-based therapeutics of skeletal muscle injury.


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

Author(s):  
Taghreed Abdul Rasool Ali ◽  
Laith Hekmat Zaki ◽  
May Fadhil Al- Habib

Background:Laminins are high-molecular-weight proteins in the extracellular matrix; it is a major component of the basal lamina, influencing cell differentiation, migration, and adhesion. Laminin affects cell growth, besides effects in wound healing and embryonic development.Objective:The present study aims to assess the histological changes taking place during skeletal muscle healing.Methods:The Extensor digitorum longus muscle of 45 male rabbits was set as a skeletal muscle injury model and examined 3&6 weeks after initiation of injury. These animals were divided into three groups control (A) group with no injury, group (B) at 3rdpost-injury week, group (C) at 6th post-injury week. The muscle tissues were prepared and examined histologically using H&E and immunohistochemically using Laminin antibodies. Aperio image scope software is used to analyze immunohistochemical reactivity quantitatively.The degeneration and regeneration process were overlapping with each other both in time and cellular morphological changes. Early myoblast like cell appearance and new myotube formation was recorded during the 3rd week. By the end of the6th-week postoperatively, the muscle histological maturation and muscle fascicles were noticed.Results:Immunohistochemical reactivity of Laminin antibody showed an intense reactivity in the 3rd-week group while a less intense reactivity in the control and 6th-week groups’.A quantitative assessment of Laminin using Aperio soft wear showed that the 3rd-week group has an intensity of 0.724 ± 0.03 pixel, while the 6th week’s group was 0. 321 ± 0.02 pixel and the control groups was 0.293 ± 0.02 pixel. The differences were statistically significant, P-value 0.0001.Conclusion: The process of regeneration is a dynamic type where degeneration andregeneration superimposed each other.


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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mirko Manetti ◽  
Alessia Tani ◽  
Irene Rosa ◽  
Flaminia Chellini ◽  
Roberta Squecco ◽  
...  

Abstract Although telocytes (TCs) have been proposed to play a “nursing” role in resident satellite cell (SC)-mediated skeletal muscle regeneration, currently there is no evidence of TC-SC morpho-functional interaction following tissue injury. Hence, we explored the presence of TCs and their relationship with SCs in an ex vivo model of eccentric contraction (EC)-induced muscle damage. EC-injured muscles showed structural/ultrastructural alterations and changes in electrophysiological sarcolemnic properties. TCs were identified in control and EC-injured muscles by either confocal immunofluorescence (i.e. CD34+CD31− TCs) or transmission electron microscopy (TEM). In EC-injured muscles, an extended interstitial network of CD34+ TCs/telopodes was detected around activated SCs displaying Pax7+ and MyoD+ nuclei. TEM revealed that TCs invaded the SC niche passing with their telopodes through a fragmented basal lamina and contacting the underlying activated SCs. TC-SC interaction after injury was confirmed in vitro by culturing single endomysial sheath-covered myofibers and sprouting TCs and SCs. EC-damaged muscle-derived TCs showed increased expression of the recognized pro-myogenic vascular endothelial growth factor-A, and SCs from the same samples exhibited increased MyoD expression and greater tendency to fuse into myotubes. Here, we provide the essential groundwork for further investigation of TC-SC interactions in the setting of skeletal muscle injury and regenerative medicine.


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