Morris G E
MRIC Biochemistry Group, N.E. Wales Institute, Wrexham, UK.
Neuromuscul Disord. 1997 Dec;7(8):493-8. doi: 10.1016/s0960-8966(97)00109-0.
The possibility of using utrophin upregulation as a treatment for dystrophin-deficient muscular dystrophies has focused attention on the question of how many of dystrophin's various functions can be performed by the closely-related protein, utrophin. In Xenopus heart, little or no dystrophin was found on Western blots but the dystrophin-related protein, utrophin, was abundant. This utrophin was shown by immunofluorescence microscopy to be associated with cardiac muscle membranes and its distribution was similar to that of dystrophin in rabbit heart. The utrophin distribution pattern in the frog heart was shared by beta-dystroglycan, a transmembrane protein responsible for localizing both dystrophin and utrophin at cell membranes. The results suggest that utrophin in Xenopus heart can perform similar functions to dystrophin in mammalian heart, lending further support to the possibility of utrophin upregulation therapy in muscular dystrophy. In skeletal muscle, however, Xenopus resembles mammals in expressing dystrophin at the sarcolemma and very little utrophin.
将上调抗肌萎缩蛋白聚糖作为治疗抗肌萎缩蛋白缺乏型肌营养不良症的一种方法，这使得人们关注一个问题：与抗肌萎缩蛋白密切相关的抗肌萎缩蛋白聚糖能够执行抗肌萎缩蛋白的多少种不同功能。在非洲爪蟾心脏中，蛋白质免疫印迹法检测到很少或几乎没有抗肌萎缩蛋白，但抗肌萎缩蛋白相关蛋白抗肌萎缩蛋白聚糖却含量丰富。免疫荧光显微镜检查显示，这种抗肌萎缩蛋白聚糖与心肌细胞膜相关，其分布与兔心脏中抗肌萎缩蛋白的分布相似。β-抗肌萎缩蛋白聚糖在蛙心脏中的分布模式与抗肌萎缩蛋白聚糖相同，β-抗肌萎缩蛋白聚糖是一种跨膜蛋白，负责将抗肌萎缩蛋白和抗肌萎缩蛋白聚糖定位在细胞膜上。结果表明，非洲爪蟾心脏中的抗肌萎缩蛋白聚糖可以执行与哺乳动物心脏中抗肌萎缩蛋白类似的功能，这进一步支持了上调抗肌萎缩蛋白聚糖治疗肌营养不良症的可能性。然而，在骨骼肌中，非洲爪蟾与哺乳动物相似，在肌膜上表达抗肌萎缩蛋白，而抗肌萎缩蛋白聚糖表达很少。
