Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois.
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois.
Am J Physiol Cell Physiol. 2019 Nov 1;317(5):C1011-C1024. doi: 10.1152/ajpcell.00156.2019. Epub 2019 Aug 21.
Unaccustomed resistance exercise can initiate skeletal muscle remodeling and adaptive mechanisms that can confer protection from damage and enhanced strength with subsequent stimulation. The myofiber may provide the primary origin for adaptation, yet multiple mononuclear cell types within the surrounding connective tissue may also contribute. The purpose of this study was to evaluate the acute response of muscle-resident interstitial cells to contraction initiated by electrical stimulation (e-stim) and subsequently determine the contribution of pericytes to remodeling as a result of training. Mice were subjected to bilateral e-stim or sham treatment. Following a single session of e-stim, NG2CD45CD31 (NG2Lin) pericyte, CD146Lin pericyte, and PDGFRα fibroadipogenic progenitor cell quantity and function were evaluated via multiplex flow cytometry and targeted quantitative PCR. Relative quantity was not significantly altered 24 h postcontraction, yet unique gene signatures were observed for each cell population at 3 h postcontraction. CD146Lin pericytes appeared to be most responsive to contraction, and upregulation of genes related to immunomodulation and extracellular matrix remodeling was observed via RNA sequencing. Intramuscular injection of CD146Lin pericytes did not significantly increase myofiber size yet enhanced ECM remodeling and angiogenesis in response to repeated bouts of e-stim for 4 wk. The results from this study provide the first evidence that CD146Lin pericytes are responsive to skeletal muscle contraction and may contribute to the beneficial outcomes associated with exercise.
不习惯的抗阻运动可以启动骨骼肌重塑和适应机制，从而提供损伤保护和增强力量，并在随后的刺激中进一步增强。肌纤维可能是适应的主要来源，但周围结缔组织中的多种单核细胞类型也可能有贡献。本研究的目的是评估肌肉驻留间质细胞对电刺激（e-stim）引发的收缩的急性反应，随后确定周细胞在训练引起的重塑中的贡献。小鼠接受双侧 e-stim 或假处理。单次 e-stim 后，通过多重流式细胞术和靶向定量 PCR 评估 NG2CD45CD31（NG2Lin）周细胞、CD146Lin 周细胞和 PDGFRα 纤维脂肪祖细胞的数量和功能。收缩后 24 小时相对数量没有明显改变，但在收缩后 3 小时观察到每个细胞群体的独特基因特征。CD146Lin 周细胞似乎对收缩最敏感，通过 RNA 测序观察到与免疫调节和细胞外基质重塑相关的基因上调。CD146Lin 周细胞的肌肉内注射并没有显著增加肌纤维大小，但在 4 周的重复 e-stim 后，增强了 ECM 重塑和血管生成。这项研究的结果首次提供了证据，表明 CD146Lin 周细胞对骨骼肌收缩有反应，并且可能与运动相关的有益结果有关。
