Different modes of renal proximal tubule regeneration in health and disease  

作　　者：Yoshihide Fujigaki First Department of Medicine Hamamatsu University School of Medicine Hamamatsu JapanAuthor contributions： Fujigaki Y solely contributed to this paper.Supported by A Grant-In-Aid for Scientific Research Yoshihide Fujigaki

机构地区：[1]First Department of Medicine, Hamamatsu University School of Medicine

出　　处：《World Journal of Nephrology》2012年第4期92-99,共8页世界肾病学杂志（英文版）

基　　金：Supported by A Grant-In-Aid for Scientific Research(C;No.22590884)from the Ministry of Education,Culture,Sports,Science,and Technology of Japan

摘　　要：Tissues are equipped with reasonable strategies for re-pair and regeneration and the renal proximal tubule （PT）is no exception. New information has become availableon the mode of PT regeneration in mammals. Unlikethe intestinal epithelium with a high rate of turnovermaintained by the stem cell system, the kidney has lowturnover under normal physiological conditions. The PTseems to be maintained physiologically by hyperplasia,a regenerating system with self-renewal of mature tu-bular cells. This mode of regeneration is advantageousfor effective replenishment of randomly isolated andeliminated tubular cells by self-renewal of adjacentcells. On the other hand, it has been suggested thatdedifferentiation of mature tubular cells plays a role inregeneration after acute kidney injury. Recent studiesemploying genetic labeling and DNA-labeling tech-niques have confrmed that the proliferation of preex-isting injured mature tubular cells contributes mainlyto PT regeneration in ischemic reperfusion injury. Thismode of regeneration is beneficial with regard to therapid reparation of focally injured tubules often inducedby ischemic reperfusion injury. What happens, howeverwhen the PT is homogeneously injured with almost noremaining surviving cells？ Is the PT equipped with another backup regeneration system, e.g., the stem cell system？ Is it possible that certain types of renal injuries evoke a stem cell response whereas others do not？ This review focuses on all three possible modes of tis-sue regeneration （compensatory hyperplasia, dediffer-entiation and stem cell system） in mammals and their involvement in PT regeneration in health and disease.Tissues are equipped with reasonable strategies for repair and regeneration and the renal proximal tubule(PT) is no exception. New information has become available on the mode of PT regeneration in mammals. Unlike the intestinal epithelium with a high rate of turnover maintained by the stem cell system, the kidney has low turnover under normal physiological conditions. The PT seems to be maintained physiologically by hyperplasia, a regenerating system with self-renewal of mature tubular cells. This mode of regeneration is advantageous for effective replenishment of randomly isolated and eliminated tubular cells by self-renewal of adjacent cells. On the other hand, it has been suggested that dedifferentiation of mature tubular cells plays a role in regeneration after acute kidney injury. Recent studies employing genetic labeling and DNA-labeling techniques have confirmed that the proliferation of preexisting injured mature tubular cells contributes mainly to PT regeneration in ischemic reperfusion injury. This mode of regeneration is beneficial with regard to the rapid reparation of focally injured tubules often induced by ischemic reperfusion injury. What happens, however, when the PT is homogeneously injured with almost no remaining surviving cells? Is the PT equipped with another backup regeneration system, e.g., the stem cell system? Is it possible that certain types of renal injuries evoke a stem cell response whereas others do not? This review focuses on all three possible modes of tissue regeneration(compensatory hyperplasia, dedifferentiation and stem cell system) in mammals and their involvement in PT regeneration in health and disease.

关 键 词：Proximal tubule REGENERATION Compensa-tory hyperplasia DEDIFFERENTIATION Stem cell Progeni-tor cell 

分 类 号：R692.02[医药卫生—泌尿科学]