检索中国知网和Pubmed数据库中相关文献并对其进行综述。持续大强度离心运动可能对与骨骼肌损伤修复密切相关的骨骼肌卫星细胞生长因子具有一定的调节作用；持续大强度离心运动引发的延迟性肌肉酸痛的发生时序与骨骼肌卫星细胞增殖时序存在一定的相关性；延迟性酸痛的骨骼肌特殊微环境一定程度上刺激骨骼肌卫星细胞生长因子的分泌，促进骨骼肌肌节重塑。

By reviewing related literatures retrieved through the CNKI and Pubmed database. the continuous intensive eccentric exercise may have certain regulation to skeletal muscle satellite cell growth factor which is closely related to repair skeletal muscle damage ; delayed onset muscle soreness sequential timing has certain correlation with skeletal muscle satellite cell proliferation; delayed ache of skeletal muscle special micro environment certain extent to stimulate the secretion of skeletal muscle satellite cell growth factor and promote skeletal muscle sarcomere remodeling.

【目的】在骨骼肌生长或损伤刺激下,骨骼肌卫星细胞被激活、增殖分化形成肌管,促进骨骼肌的生长发育或修复组织创伤。FoxO1负调控骨骼肌的生成,但在骨骼肌卫星细胞分化过程中的作用未见报道。因此,笔者探索FoxO1对猪骨骼肌卫星细胞分化的影响,希望为深入研究FoxO1调控骨骼肌生长发育的作用机理奠定基础。【方法】以1—3日龄健康大白猪为材料,采用单根肌纤维法分离培养猪骨骼肌卫星细胞,接种第2天、第4天和第6天在倒置显微镜下观察细胞形态并拍照。在细胞分化第8天,用免疫荧光染色方法染肌管,DAPI染核,并在荧光倒置显微镜下观察拍照。待细胞汇合至70%—80%时,将培养基换成含50 nmol·L-1渥曼青霉素(wortmannin,WM)的分化培养基,分别于细胞分化第0天、第4天和第8天收集细胞,提取总RNA和总蛋白,采用real-time qPCR和Western blotting方法检测WM对FoxO1以及骨骼肌卫星细胞分化标志基因表达的影响。【结果】猪骨骼肌卫星细胞在接种第2天开始贴壁,呈梭形。第4天细胞数量增加,部分发生融合。第6天时细胞呈方向性生长。第8天细胞进一步融合形成肌管。WM处理组的FoxO1 mRNA表达水平未发生显著变化(P0.05),非磷酸化的FoxO1蛋白表达显著高于对照组(P0.05),而p-FoxO1蛋白表达较对照组显著下降(P0.05)。WM处理组的细胞在分化第8天,虽然也出现了蜂窝状生长,但是与对照组相比细胞未呈方向性生长并形成肌管。Western blotting结果显示,WM明显抑制猪骨骼肌卫星细胞分化早期标志基因MyoD、中后期标志基因MyoG和末期标志基因MyHC蛋白的表达。【结论】以WM阻断PI3K信号通路能使FoxO1去磷酸化,抑制猪骨骼肌卫星细胞的分化,延迟肌管的形成,并降低成肌分化标志基因MyoD、MyoG和MyHC的表达。总之,阻断PI3K信号通路通过激活FoxO1抑制猪骨骼肌卫星细胞分化。

[Objective]Skeletal satellite cells are activated by some specific stresses such as development and trauma, and differentiate and form myotubes to participate in the development or repair of skeletal muscle. FoxO1 negatively controls the genesis of skeletal muscle, but the molecular mechanisms by which FoxO1 funcions in the differentiation of satellite cells have not been reported so far. This experiment was conducted to explore the effects of FoxO1 on porcine skeletal muscle satellite cells differentiation, aiming to provide new theoretical reference for further research. [Method]Extensor digitorum longus of 1 to 3-day-old piglets were used to isolate the skeletal muscle satellite cells and the cells were observed and pictures were taken by inverted microscope on day 2, day 4 and day 6, respectively. The cells were stained by immunofluorescence staining and DAPI nuclear staining on day 8 of differentiation, and observed under a fluorescence microscope. Meanwhile, the medium was replac

骨骼肌是具有完全再生能力的组织,在急性创伤性损害后骨骼肌多能完成再生修复。当出现慢性退行性病变如进行性肌营养不良和反复肌纤维损伤时,骨骼肌修复过程常伴随着纤维化的发生。通过近十余年来对骨骼肌纤维化机制的研究,发现多种细胞和系列调控分子参与该过程,特别是肌卫星细胞来源的肌成纤维细胞等相关细胞和转化生长因子β(TGF-β)等促纤维化发展的生长因子。本文就骨骼肌纤维化的细胞分子机制及相关拮抗策略进行综述。

Skeletal muscle has high regenerative capability. It is able to regenerate completely after acute traumatic damage, while the repairing process often accompanied by fibrosis in the chronic degenerative conditions such as muscular dystrophy and repeated muscle fi-ber damage. Through in-depth study on the mechanisms of skeletal muscle fibrosis in the past decade, it has been found that a variety of cells and regulatory molecules involved in the process, especially muscle satellite cells-derived myofibroblasts, transforming growth factor β(TGF-β) and other fibrosis promoting growth factors. This review focused on the cellular and molecular mechanisms of the skeletal muscle fibrosis and relevant antagonistic strategies.

背景：骨骼肌卫星细胞是一种具有多向分化能力的全能干细胞，存在于骨骼肌间质中，对缺血、缺氧有一定的耐受力，是干细胞工程中重要来源细胞。 目的：为联合基因工程细胞心肌成形治疗初步探讨较为简便、经济的骨骼肌卫星细胞体外培养方法，建立一种简单、高效的转染骨骼肌卫星细胞的方法及探讨转染后基因表达的特点。 方法：分离、培养兔大腿骨骼肌卫星细胞，用CKK-8法测定其生长曲线。根据质粒和脂质体不同比例分组，用脂质体介导增强型绿色荧光蛋白质粒(plasmid enhanced green fluorescent protein，pEGFP)转染骨骼肌卫星细胞。测定各组转染效率及目标基因表达特点。 结果与结论：成功分离培养骨骼肌卫星细胞及转染pEFGF。在合适的质粒和脂质体比例下，转染效率可达35%以上。目标蛋白在转染12 h内开始表达，48-72 h表达最强，1周后逐渐减弱，2周后仍可观察到其表达。阳离子脂质体可介导pEGFP高效转染骨骼肌卫星细胞，转染效率与质粒、脂质体比例密切相关，目标基因表达随时间改变。

BACKGROUND:Skeletal muscle satel ite cells are totipotential stem cells with multi-directional differentiation potential, locate in skeletal muscle interstitium, have a certain tolerance to ischemia and hypoxia, and are important cells in stem cellengineering. OBJECTIVE:To establish a thrifty, convenient culture procedure and create a simple, efficient method to transfect skeletal muscle satel ite cells, and investigate genetic expression after the transfection for cellular cardiomyoplasty. METHODS:Skeletal muscle satel ite cells were isolated from rabbit thigh and cultured. Their growth curves were determined by CKK-8 method. Grouped by different proportions of the plasmid and liposome, skeletal muscle satel ite cells were transfered by the enhanced green fluorescent protein plasmid based on liposome. Aftertransfection, the efficiency and character of target genetic expression was determined. RESULTS AND CONCLUSION:Satel ite cells were isolated, cultured and transfected successful y.

探讨高表达热休克蛋白70(heat shock protein 70,Hsp70)对骨骼肌细胞(C2C12细胞)纤维类型分化的影响。方法:通过构建重组pTRE2hyg-Hsp70质粒稳定转染C2C12细胞系,建立Hsp70高表达的C2C12细胞系。经过诱导分化形成骨骼肌纤维,观察不同时间点(0、3、7 d)C2C12细胞的分化情况,并检测骨骼肌类型标志肌球蛋白重链(myosin heavy chain,MHC)的表达情况。结果:与对照组相比,高表达Hsp70的C2C12细胞系分化后的3、7 d,MHCⅠmRNA及蛋白的表达明显增高(P0.05),而在分化后7 d,MHCⅡb mRNA及蛋白的表达明显下降(P0.05)。结论:高表达Hsp70的骨骼肌细胞C2C12可以诱导MHCⅠ的表达,促进骨骼肌细胞向Ⅰ型肌纤维转化。

Objective: To examine the effect of over-expression heat shock protein ( Hsp ) 70 on the skeletal muscle fiber transformation in C2C12 cells.Methods:Hsp70 gene was amplified from pAT153 plasmids and then cloned into pTRE2hyg vector.After the transfection of recombinant plasmids of pTRE 2hyg-Hsp70 into the C2C12 cells,the expression of Hsp70 was examined by Western blot .Furthermore,the expression of myosin heavy chain (MHC) in over-expression Hsp70 C2C12 cells was evaluated by real-time PCR and Western blot at different time points(0,3,7 d) after the differentiation of C2C12 cells.Results:Compared with controls,the mRNA and protein expression of MHCⅠwas significantly increased(P<0.05)at different time points(3,7 d) after differentiation, whereas the expression of MHCⅡb was decreased(P<0.05)at 7 d after differentiation.Conclusion:The C2C12 cells of over-expression Hsp70 can induce the enhancement of MHCⅠexpression and facilitate the transformation of type Ⅰfiber from C2C12 cells.