Characterization of huntingtin pathologic fragments in human Huntington disease, transgenic mice, and cell models
Characterization of huntingtin pathologic fragments in human Huntington disease, transgenic mice, and cell models
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DOI：
10.1097/nen.0b013e318040b2c8
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发表时间：
2007-04-01
影响因子：
3.2
通讯作者：
Borchelt, David R.
中科院分区：
文献类型：
--
作者：
Schilling, Gabriele;Klevytska, Alexandra;Borchelt, David R.
亨廷顿病（HD）是由亨廷顿蛋白（btt） N端附近的谷氨酰胺(Q)重复扩增引起的，导致突变蛋白的构象发生改变，尤其是在脑神经元、核和细胞质包涵病理中。突变体htt在细胞核中的内含物和相关弥漫性积累是由突变蛋白的n端片段组成的。在这里，我们使用了一组肽抗体来表征人类HD脑组织中htt蛋白的病理特征，并通过用82Q表达人类btt蛋白的前171个氨基酸（http - n171 -82Q）建立了转基因小鼠模型。在这两个来源的组织中，htt的病理特征可以通过抗体检测到htt肽1-17和81-90，但不能检测到115-129（野生型亨廷顿蛋白编号23个重复）。人HEK 293细胞用编码人htt蛋白n端233个氨基酸（http - n233 - 82q）或http - n171 - 18q的表达载体转染后，积累了更小的n端片段，这些片段具有与病理肽相同的抗体生成特征。我们得出结论，在人类HD的病理结构中积累的突变htt肽和小鼠的httN 171-82Q是由类似的蛋白质水解事件产生的，但尚未确定，在氨基酸90-115附近或内部的蛋白质区域。
Huntington disease (HD) is caused by the expansion of a glutamine (Q) repeat near the N terminus of huntingtin (btt), resulting in altered conformation of the mutant protein to produce, most prominently in brain neurons, nuclear and cytoplasmic inclusion pathology. The inclusions and associated diffuse accumulation of mutant htt in nuclei are composed of N-terminal fragments of mutant protein. Here, we used a panel of peptide antibodies to characterize the htt protein pathologies in brain tissues from human HD, and a transgenic mouse model created by expressing the first 171 amino acids of human btt with 82Q (htt-N171-82Q). In tissues from both sources, htt pathologic features in nuclei were detected by antibodies to htt peptides 1-17 and 81-90 but not 115-129 (wildtype huntingtin numbering with 23 repeats). Human HEK 293 cells transfected with expression vectors that encode either the N-terminal 233 amino acids of human htt (htt-N233-82Q) or htt-N171-18Q accumulated smaller N-terminal fragments with antibody-birt ding characteristics identical to those of pathologic peptides. We conclude that the mutant htt peptides that accumulate in pathologic structures of human HD and httN 171-82Q in mice are produced by similar, yet to be defined, proteolytic events in a region of the protein near or within amino acids 90-115.