进行性肌营养不良患儿肌肉组织转化生长因子-β_1的表达

Expression of transforming growth factorβ1 ( TGF2β1 ) in muscle of children with progressive muscular dystrophy

摘要:

目的 进行性肌营养不良肌纤维化的病理机制不清。转化生长因子 β1(TGF β1)能诱导细胞外基质的积聚 ,对纤维发生和组织修复起调节作用。本研究探讨进行性肌营养不良患儿肌肉TGF β1表达与肌纤维化的关系 ,阐明儿童进行性肌营养不良肌纤维化慢性病理进展的部分机制。方法 采用免疫荧光和免疫印迹的方法检测 18例进行性肌营养不良患儿 [7例Duchenne肌营养不良 (DMD) ,6例福山型和 3例非福山型先天性肌营养不良 (FCMD ,nFCMD) ,2例Becker型肌营养不良 (BMD) ]和 13例非神经肌肉疾病患者肌肉组织中TGF β1表达。结果 先天性肌营养不良 (CMD)和DMD肌组织内潜伏和活性形式的TGF β1均免疫定位于肌纤维和间质的肌内膜 ,表达强度以CMD为著。免疫印迹结果显示FCMD肌肉组织TGF β1表达强于DMD和对照。结论 在儿童进行性肌营养不良的肌肉慢性病理进展中 ,肌肉纤维化可能是重要原因之一。

Abstract:

Objective The mechanism of the fibrosis in muscles with progressive muscular dystrophy is not clear. Transforming growth factor β 1 (TGF-β 1), which can induce the extracellular matrix aggrogation, has roles in fibrogenesis and tissue repair. This study aims to explore the possible correlation between the immunolocalization of TGF-β 1 in muscle and fibrosis, and to study the mechanism of muscle progressive damages in children with progressive muscular dystrophy. Methods Eighteen children with progressive muscular dystrophy, including 7 casese of Duchenne muscular dystrophy (DMD), 6 Fukuyama type and 3 non-Fukuyama type congenital muscular dystrophy (FCMD and nFCMD), 2 Becker muscular dystrophy (BMD), were involved in this study. Thirteen cases of non-muscular disease served as the controls. The level of TGF-β 1 expression from biopsied frozen muscle were assayed by the immunohistochemical method and Western blot analysis. Results TGF-β 1 of active and latent forms were strongly expressed in the muscle fibers and emdomysium of the muscle in CMD and DMD, and the levels of expression in CMD were significantly higher. The Western bloting results also showed a stronger TGF-β 1 expression in FCMD than in DMD. TGF-β 1 expression levels in both FCMD and DMD were significantly higher than in controls. Conclusions The fibrosis in muscles might be one of the important causes of progressive muscular lesions in children with progressive muscular dystrophy.