Corvelyn Marlies, De Beukelaer Nathalie, Duelen Robin, Deschrevel Jorieke, Van Campenhout Anja, Prinsen Sandra, Gayan-Ramirez Ghislaine, Maes Karen, Weide Guido, Desloovere Kaat, Sampaolesi Maurilio, Costamagna Domiziana
Stem Cell Biology and Embryology, Department of Development and Regeneration, KU Leuven, Leuven, Belgium.
Neurorehabilitation Group, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
Front Physiol. 2020 Aug 6;11:945. doi: 10.3389/fphys.2020.00945. eCollection 2020.
Cerebral palsy (CP), the single largest cause of childhood physical disability, is characterized firstly by a lesion in the immature brain, and secondly by musculoskeletal problems that progress with age. Previous research reported altered muscle properties, such as reduced volume and satellite cell (SC) numbers and hypertrophic extracellular matrix compared to typically developing (TD) children (>10 years). Unfortunately, data on younger CP patients are scarce and studies on SCs and other muscle stem cells in CP are insufficient or lacking. Therefore, it remains difficult to understand the early onset and trajectory of altered muscle properties in growing CP children. Because muscle stem cells are responsible for postnatal growth, repair and remodeling, multiple adult stem cell populations from young CP children could play a role in altered muscle development. To this end, new methods for studying muscle samples of young children, valid to delineate the features and to elucidate the regenerative potential of muscle tissue, are necessary. Using minimal invasive muscle microbiopsy, which was applied in young subjects under general anaesthesia for the first time, we aimed to isolate and characterize muscle stem cell-derived progenitors of TD children and patients with CP. Data of 15 CP patients, 3-9 years old, and 5 aged-matched TD children were reported. The muscle microbiopsy technique was tolerated well in all participants. Through the explant technique, we provided muscle stem cell-derived progenitors from the Via fluorescent activated cell sorting, using surface markers CD56, ALP, and PDGFRa, we obtained SC-derived progenitors, mesoangioblasts and fibro-adipogenic progenitors, respectively. Adipogenic, skeletal, and smooth muscle differentiation assays confirmed the cell identity and ability to give rise to different cell types after appropriate stimuli. Myogenic differentiation in CP SC-derived progenitors showed enhanced fusion index and altered myotube formation based on MYOSIN HEAVY CHAIN expression, as well as disorganization of nuclear spreading, which were not observed in TD myotubes. In conclusion, the microbiopsy technique allows more focused muscle research in young CP patients. Current results show altered differentiation abilities of muscle stem cell-derived progenitors and support the hypothesis of their involvement in CP-altered muscle growth.
脑瘫（CP）是儿童身体残疾的单一最大原因，其首先表现为未成熟大脑的损伤，其次表现为随年龄增长而出现的肌肉骨骼问题。先前的研究报告称，与正常发育（TD）儿童（>10岁）相比，脑瘫患者的肌肉特性发生了改变，如肌肉体积减小、卫星细胞（SC）数量减少以及细胞外基质肥大。不幸的是，关于年龄较小的脑瘫患者的数据很少，对脑瘫患者的卫星细胞和其他肌肉干细胞的研究也不足或缺乏。因此，仍然难以理解正在成长的脑瘫儿童肌肉特性改变的早期发病情况和发展轨迹。由于肌肉干细胞负责出生后的生长、修复和重塑，来自年幼脑瘫儿童的多种成体干细胞群体可能在肌肉发育改变中起作用。为此，需要新的方法来研究幼儿的肌肉样本，以便有效地描绘肌肉组织的特征并阐明其再生潜力。我们首次在全身麻醉下将微创肌肉活检应用于年轻受试者，旨在分离和表征正常发育儿童和脑瘫患者肌肉干细胞衍生的祖细胞。报告了15名3至9岁的脑瘫患者和5名年龄匹配的正常发育儿童的数据。所有参与者对肌肉活检技术的耐受性都很好。通过外植技术，我们从……获得了肌肉干细胞衍生的祖细胞。通过荧光激活细胞分选，使用表面标志物CD56、碱性磷酸酶（ALP）和血小板衍生生长因子受体α（PDGFRa），我们分别获得了卫星细胞衍生的祖细胞、间充质血管祖细胞和成纤维脂肪生成祖细胞。成脂、骨骼和平滑肌分化试验证实了细胞身份以及在适当刺激后产生不同细胞类型的能力。基于肌球蛋白重链表达，脑瘫卫星细胞衍生祖细胞的肌源性分化显示融合指数增加且肌管形成改变，以及核扩散紊乱，而在正常发育的肌管中未观察到这些现象。总之，活检技术使对年幼脑瘫患者的肌肉研究更具针对性。目前的结果显示肌肉干细胞衍生祖细胞的分化能力改变，并支持它们参与脑瘫相关肌肉生长改变这一假说。
