Primary and secondary elastin-binding protein defect leads to impaired elastogenesis in fibroblasts from GM1-gangliosidosis patients
Primary and secondary elastin-binding protein defect leads to impaired elastogenesis in fibroblasts from GM1-gangliosidosis patients
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DOI：
10.1016/s0002-9440(10)61251-5
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发表时间：
2005-12-01
影响因子：
6
通讯作者：
Morrone, A
中科院分区：
文献类型：
--
作者：
Caciotti, A;Donati, MA;Morrone, A
G(M1)-神经节苷脂病是一种由酸性-半乳糖苷酶缺乏引起的溶酶体贮积障碍。除了溶酶体-半乳糖苷酶外，-半乳糖苷酶基因还编码弹性蛋白结合蛋白（EBP），缺乏EBP会损害弹性形成。利用COS-1细胞的表达研究和Western blots，我们鉴定并鉴定了四种新的和两种已知的β -半乳糖苷酶基因突变，这些突变在婴儿、青少年或成人形式的G(M1)-神经节脂质沉积症患者中检测到。然后，我们重点研究了在婴儿和青少年疾病患者的成纤维细胞中检测到的受损弹性发生。少年患者表现为结缔组织异常，尿硫酸角蛋白排泄异常，EBP降低，尽管突变仅影响β -半乳糖苷酶。由于半乳糖含糖部分可能改变EBP功能并损害弹性形成，我们评估了婴儿和青少年患者弹性形成改变的来源。根据分子分析，我们确认婴儿患者的弹性生成受损是由原发性EBP缺陷引起的。我们通过免疫组织化学、添加角化酶、可溶性/不溶性弹性蛋白测定和对弹力蛋白的放射性标记来检测幼鱼的成纤维细胞。这些实验表明，幼鱼弹性生成受损可能是由于硫酸角蛋白积累引起的继发性EBP缺乏。因此，G（M1）神经节脂质沉积症的弹性生成受损可能分别由婴儿和青少年患者成纤维细胞的原发性或继发性EBP缺陷引起。
G(M1)-gangliosidosis is a lysosomal storage disorder caused by acid beta-galactosidase deficiency. Aside from the lysosomal beta-galactosidase enzyme, the beta-galactosidase gene also encodes the elastin-binding protein (EBP), deficiency in which impairs elastogenesis. Using expression studies and Western blots of COS-1 cells, we identified and characterized four new and two known beta-galactosidase gene mutations detected in G(M1)-gangliosidosis patients with infantile, juvenile, or adult forms of disease. We then focused on impaired elastogenesis detected in fibroblasts from patients with infantile and juvenile disease. The juvenile patient showed connective-tissue abnormalities, unusual urinary keratan sulfate excretion, and an EBP reduction, despite mutations affecting only beta-galactosidase. Because galactosugar-bearing moieties may alter EBP function and impair elastogenesis, we assessed infantile and juvenile patients for the source of altered elastogenesis. We confirmed that the infantile patient's impaired elastogenesis arose from a primary EBP defect, according to molecular analysis. We examined the juvenile's fibroblasts by immunohistochemistry, addition of keratanase, soluble/insoluble elastin assay, and radiolabeling of tropoelastin. These experiments revealed that the juvenile's impaired elastogenesis likely arose from secondary EBP deficiency caused by keratan sulfate accumulation. Thus, impaired elastogenesis in G(M1)-gangliosidosis can arise from primary or secondary EBP defects in fibroblasts from infantile and juvenile patients, respectively.