Abstract:

Abstract: Objective To explore the expression profile of Wnt4 in rat kidney during renal development and its effect on
renal development. Methods Rats with embryonic age of 18 days (E 18 d) , 20 days (E 20 d) as well as postnatal age of 0 day
(P 0 d), 1 day (P 1 d), 3 days (P 3 d), 5 days (P 5 d) and 7 days (P 7 d) were selected. Expression levels of Wnt4 in rat kidney
during renal development were quantified by immunohistochemistry and Western blot in all time points. Results Immuno⁃
histochemistry analysis showed that during E 18 d to P 7 d, Wnt4 mainly expressed in proximal tubules, ureteric bud, comma
shaped bodies and S shaped bodies of nephrogenic zone; the expression in the distal tubule was weak; the expression in renal
corpuscle decreased with time; Western blot analysis showed that the expression of Wnt4 in rat kidney began to decrease from
E 18 d and reached bottom at P 1 d then rise again until P 7 d when it dropped again. Conclusion During renal development,
Wnt4 proteins were involved in the development of the nephrogenic zone through regulating canonical Wnt/β-catenin signaling
pathway, and was involved in extension of proximal tubules by inducing the non canonical Wnt/PCP signaling pathway. Expression
of Wnt4 protein in rat kidney was closely related to nephron formation and development of proximal tubules.

Key words: kidney tubules, proximal, Wnt proteins, rats, Sprague- Dawley, animal experimentation, Wnt signaling pathway, kidney development