Expression of Wnt-β-catenin signaling pathway in kidney repair following ischemia reperfusion injury / 中华肾脏病杂志

ABSTRACT

Objective To observe the change of Wnt-β-catenin signaling's location and expression in kidney repair after acute kidney injury induced by ischemla reperfusion (I/R).Methods Ischemia reperfusion injury in BAT-gal reportor mice was made and blood sample was taken from tails on the 1th day after injury. Mice were sacrified on the 2th or 7th day and kidneys and blood were collected. Renal pathological change was observed by PAS stain. The changes of location and expression of Wnt-β-catenin signaling were detected by immunofluorescence costainning X-gal-LTL, X-gal-NKCC2, X-gal-DBA respectively. The protein expressions of the Wnt4 and co-receptor Lrp6 were assessed by Western blotting. Results PAS-stained kidney sections showed desquamative or flattened epithelia, necrotic debris on day 2 and regenerating tubules on day 7. An injury-induced enhancement of the Wnt pathway response (X-gal staining) in kidney cortex and out-medulla. Immunolabelling of kidney sections from injured BAT-gal mice revealed that X-gal staining was detected in kidney epithelial cells (double-labelled with LTL or NKCC2). Western blotting showed the Wnt4 protein was up-regulated and phospho-Lrp6, indicative of active canonical Wnt signaling, was noted in kidney cortex from day 2 after I/R, but in control kidney cortex pLrp6 was not detected. Conclusion Wnt-β-catenin signaling is activited after acute kidney I/R injury and is required for tubular epithelial repair and regeneration following kidney I/R injury.