P2Y2 promotes fibroblasts activation and skeletal muscle fibrosis through AKT, ERK, and PKC

Abstract Background Skeletal muscle atrophy and fibrosis are pathological conditions that contribute to morbidity in numerous conditions including aging, cachexia, and denervation. Muscle atrophy is characterized as reduction of muscle fiber size and loss of muscle mass while muscle fibrosis is due to fibroblasts activation and excessive production of extracellular matrix. Purinergic receptor P2Y2 has been implicated in fibrosis. This study aims to elucidate the roles of P2Y2 in sleketal muscle atrophy and fibrosis. Methods Primary muscle fibroblasts were isolated from wild type and P2Y2 knockout (KO) mice and their proliferating and migrating abilities were assessed by CCK-8 and Transwell migration assays respectively. Fibroblasts were activated with TGF-β1 and assessed by western blot of myofibroblast markers including α-SMA, CTGF, and collagen I. Muscle atrophy and fibrosis were induced by transection of distal sciatic nerve and assessed using Masson staining. Results P2Y2 KO fibroblasts proliferated and migrated significantly slower than WT fibroblasts with or without TGF-β1.The proliferation and ECM production were enhanced by P2Y2 agonist PSB-1114 and inhibited by antagonist AR-C118925. TGF-β1 induced fibrotic activation was abolished by P2Y2 ablation and inhibited by AKT, ERK, and PKC inhibitors. Ablation of P2Y2 reduced denervation induced muscle atrophy and fibrosis. Conclusions P2Y2 is a promoter of skeletal muscle atrophy and activation of fibroblasts after muscle injury, which signaling through AKT, ERK and PKC. P2Y2 could be a potential intervention target after muscle injury.

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Angiotensin-(1-7) Prevents Skeletal Muscle Atrophy Induced by Transforming Growth Factor Type Beta (TGF-β) via Mas Receptor Activation

Cellular Physiology and Biochemistry ◽

10.1159/000452522 ◽

2016 ◽

Vol 40 (1-2) ◽

pp. 27-38 ◽

Cited By ~ 15

Author(s):

Johanna Ábrigo ◽

Felipe Simon ◽

Daniel Cabrera ◽

Claudio Cabello-Verrugio

Keyword(s):

Skeletal Muscle ◽

Growth Factor ◽

Western Blot ◽

Muscle Atrophy ◽

Transforming Growth Factor ◽

Fibre Diameter ◽

Skeletal Muscle Atrophy ◽

Mas Receptor ◽

Factor Type ◽

Tgf Β1

Background: Transforming growth factor type beta 1 (TGF-β1) produces skeletal muscle atrophy. Angiotensin-(1-7) (Ang-(1-7)), through the Mas receptor, prevents the skeletal muscle atrophy induced by sepsis, immobilization, or angiotensin II (Ang-II). However, the effect of Ang-(1-7) on muscle wasting induced by TGF-β1 is unknown. Aim: To evaluate whether Ang-(1-7)/Mas receptor axis could prevent the skeletal muscle atrophy induced by TGF-β1. Methods: This study assessed the atrophic effect of TGF-β1 in C2C12 myotubes and mice in absence or presence of Ang-(1-7), and the receptor participation using A779, an antagonist of the Mas receptor. The levels of myosin heavy chain (MHC), polyubiquitination, and MuRF-1 were detected by western blot. Myotube diameter was also evaluated. In vivo analysis included the muscle strength, fibre diameter, MHC and MuRF-1 levels by western blot, and ROS levels by DCF probe detection. Results: The results showed that Ang-(1-7) prevented the increase in MuRF-1 and polyubiquitined protein levels, the decrease of MHC levels, the myotubes/fibre diameter diminution, and the increased production of reactive oxygen species (ROS) induced by TGF-β1. Utilizing A779 inhibited the anti-atrophic effect of Ang-(1-7). Conclusion: The preventive effect of Ang-(1-7) on skeletal muscle atrophy induced by TGF-β1 is produced through inhibition of ROS production and proteasomal degradation of MHC.

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The Combination of Electroacupuncture and Massage Therapy Alleviates Myofibroblast Transdifferentiation and Extracellular Matrix Production in Blunt Trauma-Induced Skeletal Muscle Fibrosis

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2021/5543468 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Na Zhao ◽

Bo Liu ◽

Si-Wen Liu ◽

Wei Zhang ◽

Hua-Nan Li ◽

...

Keyword(s):

Skeletal Muscle ◽

Extracellular Matrix ◽

Growth Factor ◽

Blunt Trauma ◽

Massage Therapy ◽

Muscle Fibrosis ◽

Extracellular Matrix Production ◽

Matrix Production ◽

Skeletal Muscle Fibrosis ◽

Tgf Β1

Complementary therapies, such as acupuncture and massage, had been previously reported to have therapeutic effects on skeletal muscle contusions. However, the recovery mechanisms on skeletal muscles after blunt trauma via the combination of electroacupuncture (EA) and massage therapy remain unclear. In the present study, a rat model of the skeletal muscle fibrosis following blunt trauma to rat skeletal muscle was established, and the potential molecular mechanisms of EA + massage therapy on the skeletal muscle fibrosis were investigated. The results suggested that EA + massage therapy could significantly decrease inflammatory cells infiltration and collagenous fiber content and ameliorate the disarrangement of sarcomeres within myofibrils compared to the model group. Further analysis revealed that EA + massage therapy could reduce the degree of fibrosis and increase the degree of myofibroblast apoptosis by downregulating the mRNA and protein expression of transforming growth factor- (TGF-) β1 and connective tissue growth factor (CTGF). Furthermore, the fibrosis of injured skeletal muscle was inhibited after treatment through the normalization of balance between matrix metalloproteinase- (MMP-) 1 and tissue inhibitor of matrix metalloproteinase (TIMP). These findings suggested that the combination of electroacupuncture and massage therapy could alleviate the fibrotic process by regulating TGF β1-CTGF-induced myofibroblast transdifferentiation and MMP-1/TIMP-1 balance for extracellular matrix production.

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Adipose-Derived Stem Cells Alleviate Radiation-Induced Muscular Fibrosis by Suppressing the Expression of TGF-β1

Stem Cells International ◽

10.1155/2016/5638204 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Wei Sun ◽

Xinchu Ni ◽

Suping Sun ◽

Leiming Cai ◽

Jingping Yu ◽

...

Keyword(s):

Skeletal Muscle ◽

Stem Cells ◽

Transforming Growth Factor ◽

Adipose Derived Stem Cells ◽

Peripheral Tissues ◽

Muscle Fibrosis ◽

Muscle Tissues ◽

Radiation Induced ◽

Skeletal Muscle Fibrosis ◽

Tgf Β1

We aim to investigate the effects of adipose-derived stem cells (ASCs) transplantation on irradiation-induced skeletal muscle fibrosis. Sixty-four rabbits were randomly divided into ASCs group and PBS group followed by irradiation at unilateral hip with a single dose of 80 Gy. Nonirradiated side with normal skeletal muscle served as normal control. Skeletal muscle tissues were collected from eight rabbits in each group at 1 w, 4 w, 8 w, and 26 w after irradiation. Migration of ASCs was observed in the peripheral tissues along the needle passage in the injured muscle. The proportion of the area of collagen fibers to the total area in sections of ASCs group was lower than those of PBS groups at 4 w, 8 w, and 26 w after irradiation. Significant decrease was noted in the integrated optimal density of the transforming growth factorβ1 (TGF-β1) in the ASCs group compared with those of PBS group at 4 w, 8 w, and 26 w after irradiation. Moreover, the expression of TGF-β1 was lower in the ASCs group compared to those of the PBS group at each time point determined by Western blot analysis. ASCs transplantation could alleviate irradiation fibrosis by suppressing the level of TGF-β1 in the irradiated skeletal muscle.

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PO-232 The Regulation of Vimentin in Skeletal Muscle Fibrosis Affected by High-load Exercise

Exercise Biochemistry Review ◽

10.14428/ebr.v1i5.10613 ◽

2018 ◽

Vol 1 (5) ◽

Author(s):

Xiaoran Liu

Keyword(s):

Skeletal Muscle ◽

Connective Tissue ◽

Muscle Fiber ◽

Tissue Growth ◽

High Load ◽

Control Group ◽

Vimentin Expression ◽

Muscle Fibrosis ◽

Skeletal Muscle Fibrosis ◽

Tgf Β1

Objective Long-term movement could induce micro-damage of skeletal muscle, increase collagen significantly, and appear skeletal muscle fibrosis. Vimentin is one of the most important proteins in evaluating the fibrosis after muscle injury. TGF-β1 could up-regulate Vimentin expression, promoting cell migration and accelerating fibrosis and injury repair. This study mainly explored the role of TGF-β1/Vim in skeletal muscle fibrosis affected by a bout of high-load exercise. And we tried to find whether the expression of vimentin could regulate the regeneration of muscle fiber and the remodeling of connective tissue. Methods SD rats were divided into 7groups: control group, immediately, 6-hour, 12-hour, 24-hour, 48-hour and 72-hour after group. Western Blot was used to detect TGF-β1, vimentin, RhoA, ROCK1 and CTGF(connective tissue growth factor) expressions. Electron microscopy was used to observe the changes of collagen in skeletal muscle. Results Vimentin protein exprsssion increased quickly at 6-hour after exerciese. At 48-hour, the vimentin expression reached the peak. And then the expression of vimentin gradually decreased. The expressions of TGF-β1, RhoA, ROCK1 and CTGF gradually increased after exercise. The peak of these expressions appeared at 12-hour respectively. Then these protein expressions declined slowly. Collagen in skeletal muscle became long and thick in 48-hour and 72-hour after exercise. Conclusions A bout of high-load exercise could induce skeletal muscle fibrosis. RhoA-ROCK1 maybe affect TGF-β1/Vim expressions as main regulators, and then the protein expression vimentin could regulate the regeneration of muscle fiber and the remodeling of connective tissue as an important evaluation factor.

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