Tajima Hirohisa, Niikura Takako, Hashimoto Yuichi, Ito Yuko, Kita Yoshiko, Terashita Kenzo, Yamazaki Kazuto, Koto Atsuo, Aiso Sadakazu, Nishimoto Ikuo
Department of Pharmacology and Neurosciences, KEIO University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
Neurosci Lett. 2002 May 24;324(3):227-31. doi: 10.1016/s0304-3940(02)00199-4.
An unbiased functional screening with brain cDNA library from an Alzheimer's disease (AD) brain identified a novel 24-residue peptide Humanin (HN), which suppresses AD-related neurotoxicity. As the 1567-base cDNA containing the open reading frame (ORF) of HN is 99% identical to mitochondrial 16S ribosomal RNA as well as registered human mRNA, it was elusive whether HN is produced in vivo. Here, we raised anti-HN antibody and found that long cDNAs containing the ORF of HN (HN-ORF) produced the HN peptide in mammalian cells, dependent on the presence of full-length HN-ORF. Immunoblot analysis detected a 3-kDa protein with HN immunoreactivity in the testis and the colon in 3-week-old mice and in the testis in 12-week-old mice. HN immunoreactivity was also detected in an AD brain, but little in normal brains. This study suggests that HN peptide could be produced in vivo, and would provide a novel insight into the pathophysiology of AD.
用阿尔茨海默病（AD）患者大脑的cDNA文库进行的无偏差功能筛选，鉴定出一种新型的24个氨基酸的肽——人胰岛素（HN），它可抑制与AD相关的神经毒性。由于包含HN开放阅读框（ORF）的1567个碱基的cDNA与线粒体16S核糖体RNA以及已登记的人类mRNA有99%的同一性，因此HN是否在体内产生尚不清楚。在此，我们制备了抗HN抗体，发现含有HN ORF的长cDNA（HN-ORF）在哺乳动物细胞中产生HN肽，这依赖于全长HN-ORF的存在。免疫印迹分析在3周龄小鼠的睾丸和结肠以及12周龄小鼠的睾丸中检测到一种具有HN免疫反应性的3 kDa蛋白。在AD患者大脑中也检测到HN免疫反应性，但在正常大脑中几乎没有。这项研究表明HN肽可能在体内产生，并将为AD的病理生理学提供新的见解。
