Sarkozi E, Askanas V, Johnson S A, Engel W K, Alvarez R B
Department of Neurology, University of Southern California, School of Medicine, Los Angeles 90017.
Neuroreport. 1993 Jun;4(6):815-8. doi: 10.1097/00001756-199306000-00055.
Vacuolated muscle fibers in muscle biopsies of 8 out of 8 inclusion body myositis (IBM) patients, including 2 hereditary patients, manifested increased mRNA for the beta-amyloid precursor protein (beta APP) that contains Kunitz-type protease inhibitor motif. In affected fibers, increased beta APP-mRNA correspond to abnormally accumulated beta APP immunoreactivity (including beta-amyloid protein epitope). In normal human muscle fibers increased beta APP-mRNA was present only at the neuromuscular junctions. Our study (a) suggests that abnormally accumulated beta APP in IBM vacuolated fibers results, at least partly, from increased beta APP generation, and (b) provides the first demonstration of up-regulated beta APP-mRNA in pathologic human tissue other than brain of Alzheimer's disease and Down's syndrome.
8 例包涵体肌炎（IBM）患者（包括 2 例遗传性患者）的肌肉活检中均发现有空泡化肌纤维，这些肌纤维中含有 Kunitz 型蛋白酶抑制剂基序的β-淀粉样前体蛋白（βAPP）的 mRNA 表达增加。在受累肌纤维中，βAPP-mRNA 增加与βAPP 免疫反应性异常积聚（包括β-淀粉样蛋白表位）相对应。在正常人肌纤维中，βAPP-mRNA 仅在神经肌肉接头处出现增加。我们的研究（a）表明，IBM 空泡化纤维中βAPP 的异常积聚至少部分是由于βAPP 生成增加所致，并且（b）首次证明了在阿尔茨海默病和唐氏综合征脑以外的病理性人体组织中βAPP-mRNA 上调。
