Expression and regulation of aquaporins in cystic epithelial cells of mice with polycystic kidney disease / 中华肾脏病杂志

ABSTRACT

Objective To study the expression and regulation of aquapofins (AQP) in cystic epithelial cells of jck mice with polycystic kidney disease. Methods Localization and regulation of AQP1, AQP2, AQP3 and AQP4 protein were analyzed by using the immunofluorescence and Western blotting. Results Kidneys of jck homozygous mice were 4 folds larger than those of litter matched wild-type mice. There were multiple cysts and fibrosis in the renal tissue of jck mice. The epithelial cells in cysts were flat in shape. Blood urea level in jck mice was (42.6 ± 6.7) mmol/L, which was 5 folds higher than that in wild-type mice [(8.4±1.9) mmol/L] (P<0.01). Immunofluorescence analysis showed that AQP1 was expressed in the apical and hasolatend membranes of epithelial cells in proximal tubules, as well as in the thin descending limb of Henle and endothelial cells of descending vasa recta. There was no AQP1 expression in epithelial cells of cysts. AQP2 was expressed in the apical membranes of collecting ducts and renal cysts. AQP3 and AQP4 were expressed in basolateral membranes of collecting duct and renal cystic epithelial cells of jck mice. Western blot analysis showed the same protein sizes of AQP1, AQP2, AQP3 and AQP4 in both jck and wild-type kidneys. However, AQP1 expression was down-regulated in jck kidneys (P<0.01). Conclusion The renal cystic epithelia expresses AQP2, AQP3 and AQP4, which indicates that epithelial cells in renal cysts are derived from renal collecting ducts in jck mice and aquaporins may play an important role in renal cyst development.