Preservation of peritubular capillary endothelial integrity and increasing pericytes may be critical to recovery from postischemic acute kidney injury.
Decreased renal blood flow following an ischemic insult contributes to a reduction in glomerular filtration. However, little is known about the underlying cellular or subcellular mechanisms mediating reduced renal blood flow in human ischemic acute kidney injury (AKI) or acute renal failure (ARF). To examine renal vascular injury following ischemia, intraoperative graft biopsies were performed after reperfusion in 21 cadaveric renal allografts. Confocal fluorescence microscopy was utilized to examine vascular smooth muscle and endothelial cell integrity as well as peritubular interstitial pericytes in the biopsies. The reperfused, transplanted kidneys exhibited postischemic injury to the renal vasculature, as demonstrated by disorganization/disarray of the actin cytoskeleton in vascular smooth muscle cells and disappearance of von Willebrand factor from vascular endothelial cells. Damage to peritubular capillary endothelial cells was more severe in subjects destined to have sustained ARF than in those with rapid recovery of their graft function. In addition, peritubular pericytes/myofibroblasts were more pronounced in recipients destined to recover than those with sustained ARF. Taken together, these data suggest damage to the renal vasculature occurs after ischemia-reperfusion in human kidneys. Preservation of peritubular capillary endothelial integrity and increasing pericytes may be critical to recovery from postischemic AKI.
Kwon
Osun
O
Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA. okwon@psu.edu
Hong
Seok-Min
SM
Sutton
Timothy A
TA
Temm
Constance J
CJ
D000199:Actins / Q000378:metabolism; D000208:Acute Disease; D058186:Acute Kidney Injury / Q000473:pathology / Q000503:physiopathology; D001706:Biopsy; D004730:Endothelium, Vascular / Q000166:cytology / Q000473:pathology*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000473:pathology* / Q000503:physiopathology; D016030:Kidney Transplantation / Q000473:pathology / Q000502:physiology; D007684:Kidney Tubules / Q000098:blood supply* / Q000166:cytology / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D020286:Pericytes / Q000473:pathology*; D020127:Recovery of Function / Q000502:physiology*; D015427:Reperfusion Injury / Q000473:pathology* / Q000503:physiopathology
D000199:Actins