Padanilam B J, Lewington A J, Hammerman M R
George M. O'Brien Kidney and Urological Diseases Center, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
Kidney Int. 1998 Dec;54(6):1967-75. doi: 10.1046/j.1523-1755.1998.00197.x.
Studies identifying genes that are differentially expressed following induction of acute ischemic injury have been useful in delineating the pathophysiology of acute renal failure.
A differential cDNA library screening technique was used to identify genes that are differentially expressed in rat kidney following induction of acute ischemic renal injury.
Levels of mRNA with a high homology to that coding for Siva, a human proapoptotic protein, were increased approximately 4.5-fold in kidneys obtained from rats within 12 hours following ischemia, compared to kidneys from sham-operated rats. A partial cDNA sequence for the rat protein (rat Siva) was determined that overlaps 92% of the human open reading frame. The cDNA sequence predicts a protein 177 amino acids in length with 76% homology to human Siva. Levels of rat Siva in kidneys were elevated at one, five and seven days post-ischemia were not different from those in kidneys from sham-operated controls. In situ hybridization demonstrated that rat Siva mRNA was expressed in cells lining damaged sections in the S3 segment of the proximal tubule at 12 hours and one day post-ischemia. At five and seven days, Siva mRNA was located in epithelial cells of regenerating tubules including in papillary proliferations. TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive cells colocalized with cells containing Siva mRNA. CD27, the receptor for Siva was localized by immunohistochemistry to sloughed cells in the lumens of damaged S3 segments at 12 hours post-ischemia and to cells within papillary proliferations at five days post-injury.
Siva that is produced within the kidney could be a mediator of apoptosis post-ischemia via an interaction with CD27.
鉴定急性缺血性损伤诱导后差异表达基因的研究，对于阐明急性肾衰竭的病理生理学很有帮助。
采用差异cDNA文库筛选技术，鉴定急性缺血性肾损伤诱导后大鼠肾脏中差异表达的基因。
与假手术大鼠的肾脏相比，缺血后12小时内从大鼠获取的肾脏中，与人类促凋亡蛋白Siva编码序列具有高度同源性的mRNA水平增加了约4.5倍。确定了大鼠蛋白（大鼠Siva）的部分cDNA序列；该序列与人类开放阅读框重叠92%。cDNA序列预测的蛋白长度为177个氨基酸，与人类Siva的同源性为76%。缺血后1天、5天和7天大鼠肾脏中Siva的水平与假手术对照组肾脏中的水平无差异。原位杂交显示，缺血后12小时和1天时，大鼠Siva mRNA在近端小管S3段受损部位的衬里细胞中表达。在5天和7天时，Siva mRNA位于再生小管的上皮细胞中，包括乳头增生部位。TdT介导的dUTP生物素缺口末端标记（TUNEL）阳性细胞与含有Siva mRNA的细胞共定位。通过免疫组织化学将Siva的受体CD27定位到缺血后12小时受损S3段管腔中的脱落细胞以及损伤后5天乳头增生部位的细胞。
肾脏内产生的Siva可能通过与CD27相互作用，成为缺血后细胞凋亡的介质。
