Exosomes derived from inflammatory myoblasts promote M1 polarization and break the balance of myoblast proliferation/differentiation

microRNAs play an important role in the growth and development of chicken embryos, including the regulation of skeletal muscle genesis, myoblast proliferation, differentiation, and apoptosis. Our previous RNA-seq studies showed that microRNA-27b-3p (miR-27b-3p) might play an important role in regulating the proliferation and differentiation of chicken primary myoblasts (CPMs). However, the mechanism of miR-27b-3p regulating the proliferation and differentiation of CPMs is still unclear. In this study, the results showed that miR-27b-3p significantly promoted the proliferation of CPMs and inhibited the differentiation of CPMs. Then, myostatin (MSTN) was confirmed to be the target gene of miR-27b-3p by double luciferase reporter assay, RT-qPCR, and Western blot. By overexpressing and interfering with MSTN expression in CPMs, the results showed that overexpression of MSTN significantly inhibited the proliferation and differentiation of CPMs. In contrast, interference of MSTN expression had the opposite effect. This study showed that miR-27b-3p could promote the proliferation of CPMs by targeting MSTN. Interestingly, both miR-27b-3p and MSTN can inhibit the differentiation of CPMs. These results provide a theoretical basis for further understanding the function of miR-27b-3p in chicken and revealing its regulation mechanism on chicken muscle growth.

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Effect of ionizing radiation on human skeletal muscle precursor cells

Radiology and Oncology ◽

10.2478/raon-2013-0058 ◽

2013 ◽

Vol 47 (4) ◽

pp. 376-381 ◽

Cited By ~ 9

Author(s):

Mihaela Jurdana ◽

Maja Cemazar ◽

Katarina Pegan ◽

Tomaz Mars

Keyword(s):

Skeletal Muscle ◽

Stress Response ◽

Ionizing Radiation ◽

Human Skeletal Muscle ◽

Long Term Effects ◽

Post Irradiation ◽

Acute Response ◽

Proliferation Capacity ◽

Myoblast Proliferation

Abstract Background. Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures. Materials and methods. Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin - 6 (IL-6) release and stress response detected by the heat shock protein (HSP) level, while long term effects were followed by proliferation capacity and cell death. Results. Compared with non-irradiated control and cells treated with inhibitor of cell proliferation Ara C, myoblast proliferation decreased 72 h post-irradiation, this effect was more pronounced with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity revealed increased activity after exposure to irradiation. The acute response of myoblasts to lower doses of irradiation (4 and 6 Gy) was decreased secretion of constitutive IL-6. Higher doses of irradiation triggered a stress response in myoblasts, determined by increased levels of stress markers (HSPs 27 and 70). Conclusions. Our results show that myoblasts are sensitive to irradiation in terms of their proliferation capacity and capacity to secret IL-6. Since myoblast proliferation and differentiation are a key stage in muscle regeneration, this effect of irradiation needs to be taken in account, particularly in certain clinical conditions.

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CircRILPL1 promotes muscle proliferation and differentiation via binding miR-145 to activate IGF1R/PI3K/AKT pathway

Cell Death and Disease ◽

10.1038/s41419-021-03419-y ◽

2021 ◽

Vol 12 (2) ◽

Author(s):

Xuemei Shen ◽

Jia Tang ◽

Rui Jiang ◽

Xiaogang Wang ◽

Zhaoxin Yang ◽

...

Keyword(s):

Signaling Pathway ◽

Muscle Development ◽

Inhibitory Effect ◽

Akt Signaling ◽

Luciferase Assay ◽

Circular Rnas ◽

Akt Signaling Pathway ◽

Sequencing Data ◽

Proliferation And Differentiation ◽

Myoblast Proliferation

AbstractMany novel non-coding RNAs, such as microRNAs (miRNAs) and circular RNAs (circRNAs), are involved in various physiological and pathological processes. The PI3K/AKT signaling pathway is important for its role in regulating skeletal muscle development. In this study, molecular and biochemical assays were used to confirm the role of miRNA-145 (miR-145) in myoblast proliferation and apoptosis. Based on sequencing data and bioinformatics analysis, we identified a new circRILPL1, which acts as a sponge for miR-145. The interactions between circRILPL1 and miR-145 were examined by bioinformatics, a luciferase assay, and RNA immunoprecipitation. Mechanistically, knockdown or exogenous expression of circRILPL1 in the primary myoblasts was performed to prove the functional significance of circRILPL1. We investigated the inhibitory effect of miR-145 on myoblast proliferation by targeting IGF1R to regulate the PI3K/AKT signaling pathway. A novel circRILPL1 was identified that could sponge miR-145 and is related to AKT activation. In addition, circRILPL1 was positively correlated with muscle proliferation and differentiation in vitro and could inhibit cell apoptosis. The newly identified circRILPL1 functions as a miR-145 sponge to regulate the IGF1R gene and rescue the inhibitory effect of miR-145 on the PI3K/AKT signaling pathway, thereby promoting myoblast growth.

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