EXPRESSION OF DYSTROPHIN AND ITS ASSOCIATED PROTEINS FOLLWING MYOBLAST TRANSPLANTATION INTO MDX MICE.

肌营养不良蛋白是杜氏肌营养不良症（DMD）的一种负责蛋白，存在于正常肌膜的原生质表面。在DMD和mdx（小鼠等效DMD）肌肉中观察到它的缺失，并被认为是肌纤维变性的原因。将正常营养不良基因的成肌细胞注射到mdx小鼠肌肉中，构建mdx肌上皮下肌营养不良蛋白底被。我们将正常小鼠肌肉细胞系C2 myblasts注射到mdx裸鼠肌肉中。C2成肌细胞移植后出现大量肌营养不良蛋白阳性纤维。我们用抗肌营养不良蛋白相关蛋白抗体检测肌营养不良蛋白阳性纤维。我们报道了肌营养不良蛋白相关蛋白在生物化学上分为3类，即肌营养不良聚糖复合物和syntrophin复合物。我们还克隆了一个新的肌聚糖（γ -肌聚糖）cDNA，并发现人类γ -肌聚糖基因位于染色体13q12上，并且在3个家族和4例SCARMD散发病例中的1例中鉴定出改变其阅读框的突变。在腺病毒介导的基因转移后，lacZ基因在成年C57BL/10ScSn小鼠骨骼肌中高效转导和表达。在鸡b-肌动蛋白启动子和巨细胞病毒增强子的控制下，注射lacZ基因后，62%的胫骨前肌肌纤维呈b-半乳糖苷酶阳性。该基因在氧化酶含量高于IIB型纤维的IIA型和IIX型纤维中优先表达。

Dystropin is a responsible protein of Duchenne muscular dystrophy (DMD) and is present at the protoplasmic surface of normal sarcolemma. Its absencd is observed in DMD and mdx (mouse equivalent to DMD) muscles and is considered to be the cause of muscle fiber degeneration. To construct the subsarcolemmal dystrophin-undercoat in mdx muscle, myoblasts with normal dystrophy gene are injected into mdx mouse muscle. We injected C2 myblasts, a normal mouse muscle cell line, into the muscles of mdx nude mouse. A large number of dystrophin-positive fibers appeared after C2 myoblast transplantation. We examined dystrophin-positive fibers with antidystrophin associated proteins antibodies. We reported that dystrophin-associated proteins are biochemically classified into 3 groups, namely, dystroglycan complex and syntrophin complex. We also cloned a new sarcoglycan (gamma-sarcoglydan) cDNA and showed that the human gamma-sarcoglycan gene was mappetd to chromosome 13q12 and delations that alter its reading frame were identified in three families and one of four sporadic cases of SCARMD.We showed the efficient transduction and expression of lacZ gene in the skeletal muscle of adult C57BL/10ScSn mice after adenovirus-mediated gene transfer. Sixty-two percent of the myofibers in the tibialis anterior (TA) muscle were b-galactosidase-positive after injection of the lacZ gene under the control of the chicken b-actin promoter and the cytomegalovirus enhancer. The transduced gene was preferentially expressed in type IIA and IIX fibers which were richer in oxidative enzymes than type IIB fibers.