Abstract：
Stem cell therapy holds significant potential for skeletal muscle repair, with in vitro-generated human muscle reserve cells (MuRCs) emerging as a source of quiescent myogenic stem cells that can be injected to enhance muscle regeneration. However, the clinical translation of such therapies is hampered by the need for fetal bovine serum (FBS) during the in vitro generation of human MuRCs. This study aimed to determine whether fresh allogeneic human platelet-rich plasma (PRP) combined or not with hyaluronic acid (PRP-HA) could effectively replace xenogeneic FBS for the ex vivo expansion and differentiation of human primary myoblasts. Cells were cultured in media supplemented with either PRP or PRP-HA and their proliferation rate, cytotoxicity and myogenic differentiation potential were compared with those cultured in media supplemented with FBS. The results showed similar proliferation rates among human myoblasts cultured in PRP, PRP-HA or FBS supplemented media, with no cytotoxic effects. Human myoblasts cultured in PRP or PRP-HA showed reduced fusion ability upon differentiation. Nevertheless, we also observed that human MuRCs generated from PRP or PRP-HA myogenic cultures, exhibited increased Pax7 expression and delayed re-entry into the cell cycle upon reactivation, indicating a deeper quiescent state of human MuRCs. These results suggest that allogeneic human PRP effectively replaces FBS for the ex vivo expansion and differentiation of human myoblasts and favors the in vitro generation of Pax7High human MuRCs, with important implications for the advancement of stem cell-based muscle repair strategies.
摘要：
干细胞疗法对骨骼肌修复具有重要的潜力，体外产生的人肌肉储备细胞（MuRC）作为静态肌源性干细胞的来源，可以注射以增强肌肉再生。然而,在体外产生人MuRC期间,需要胎牛血清(FBS),这类疗法的临床转化受到阻碍。本研究旨在确定新鲜同种异体人富血小板血浆（PRP）是否与透明质酸（PRP-HA）结合可以有效替代异种FBS用于人原代成肌细胞的离体扩增和分化。细胞在补充有PRP或PRP-HA的培养基中培养，将细胞毒性和成肌分化潜能与在补充有FBS的培养基中培养的细胞毒性和成肌分化潜能进行比较。结果显示在PRP中培养的人成肌细胞之间的增殖率相似，PRP-HA或FBS补充培养基，没有细胞毒性作用。在PRP或PRP-HA中培养的人成肌细胞在分化后显示出降低的融合能力。然而，我们还观察到从PRP或PRP-HA生肌培养物中产生的人MuRC，显示Pax7表达增加，并在重新激活后延迟重新进入细胞周期，表明人类MuRC处于更深的静止状态。这些结果表明，同种异体人PRP有效替代FBS用于人成肌细胞的离体扩增和分化，并有利于Pax7High人MuRC的体外生成，对推进基于干细胞的肌肉修复策略具有重要意义。
