Lewington A J, Padanilam B J, Martin D R, Hammerman M R
George M. O'Brien Kidney and Urological Diseases Center, Renal Division, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Am J Physiol Regul Integr Comp Physiol. 2000 Jan;278(1):R247-54. doi: 10.1152/ajpregu.2000.278.1.R247.
De novo CD44 and ligand expression at wound margins accompanies cellular proliferation and migration that effect repair of injured mucosal and vascular endothelial tissues. To determine whether CD44 could play a role in recovery from acute ischemic renal injury, we characterized its renal expression and those of two of its ligands, hyaluronic acid and osteopontin. Although no expression is detectable in nonischemic kidneys, several mRNAs for CD44 are present within 1 day after injury. CD44 mRNA is expressed in proximal tubules undergoing repair. CD44 peptide is present in basal and lateral cell membranes. Hyaluronic acid is normally expressed in the interstitium of the renal papilla only. By 1 day postischemia, hyaluronic acid can be detected, in addition, in the interstitium surrounding regenerating tubules. Osteopontin, not normally expressed in the renal proximal tubule, is expressed in regenerating tubules by 3 days after induction of acute ischemic injury. Immunoreactive osteopontin peptide continues to be localized in those tubules still undergoing repair for as long as 7 days after the injury. Our data are consistent with a role for CD44-ligand interactions in the regenerating proximal tubule participating in the process of recovery after ischemic injury.
伤口边缘处新生的CD44及其配体表达伴随着细胞增殖和迁移，这些过程影响受损黏膜和血管内皮组织的修复。为了确定CD44是否在急性缺血性肾损伤的恢复中发挥作用，我们对其在肾脏中的表达以及它的两种配体透明质酸和骨桥蛋白的表达进行了表征。虽然在非缺血性肾脏中检测不到表达，但在损伤后1天内存在几种CD44的mRNA。CD44 mRNA在正在进行修复的近端小管中表达。CD44肽存在于基底细胞膜和侧细胞膜中。透明质酸通常仅在肾乳头的间质中表达。缺血后1天，除了在再生小管周围的间质中，还能检测到透明质酸。骨桥蛋白通常不在肾近端小管中表达，在急性缺血性损伤诱导后3天，在再生小管中表达。免疫反应性骨桥蛋白肽在损伤后长达7天仍定位在那些仍在进行修复的小管中。我们的数据与CD44-配体相互作用在参与缺血性损伤后恢复过程的再生近端小管中发挥作用一致。
