ZEB2 signaling is essential for ureteral smooth muscle cell differentiation and maintenance
Authors: Kumar Sudhir , Fan Xueping , Pattam Harshita , Yan Kun , Liaw Easton Jinhun , Ji Jiayi , Zaltz Emily , Song Paul , Jiang Yuqiao , Nishizaki Yuriko , Higashi Yujiro , Cai Chen-Leng , Lu Weining 
Published: February 2025

Mowat-Wilson Syndrome (MWS) is a multiple congenital anomaly syndrome caused by mutations in theZEB2,which plays a critical role in cell fate determination and differentiation during development. Congenital anomalies of the kidney and urinary tract (CAKUT) have been reported in MWS patients. However, the role of ZEB2 in urinary tract development and the cellular and molecular mechanism underlining the CAKUT phenotypes in MWS remains unknown. We performed ZEB2 protein expression analysis in the developing mouse ureter. We generatedZeb2ureteral mesenchyme-specific conditional knockout mice by crossingZeb2floxed mice with Tbx18Cre mice (Zeb2cKO) and analyzed the urinary tract phenotypes inZeb2cKO mice and wild-type littermate controls by gross and histological examination. Ureteral cellular and molecular phenotypes were studied using TAGLN, ACTA2, FOXD1, POSTN, CDH1, TBX18, and SOX9 ureteral cell-specific markers. We found that ZEB2 is expressed in TBX18+ureteral mesenchymal cells during mouse ureter development. Deletion ofZeb2in developing ureteral mesenchymal cells causes hydroureter and hydronephrosis phenotypes, leading to obstructive uropathy, kidney failure, and early mortality. Cellular and molecular marker analyses showed that the TAGLN+ACTA2+ureteral smooth muscle cells (SMCs) layer is not formed inZeb2cKO mice at E15.5, but the FOXD1+and POSTN+tunica adventitia cells layer is significantly expanded compared to wild-type controls. CDH1+urothelium cells are reduced considerably in theZeb2cKO ureters at E15.5. Mechanistically, we found thatZeb2cKO mice have significantly decreased TBX18 expression but an increased SOX9 expression in the developing ureter at E14.5 and E15.5 compared to wild-type littermate controls. Our results show that ZEB2 is essential for ureter development by maintaining ureteral mesenchymal cell differentiation into normal ureteral SMCs. Our study also shed new light on the pathological mechanism underlying the developmental abnormalities of the urinary tract phenotypes in MWS patients.

Author Summary

Hydroureter and hydronephrosis are common congenital anomalies with high incidence (1:100 to 1:500) that can lead to obstructive uropathy and renal failure in the pediatric population. Mowat-Wilson Syndrome (MWS), caused by heterozygous mutations in theZEB2gene, is a genetic disease with multiple congenital developmental defects, including hydroureter and hydronephrosis. However, the molecular function of ZEB2 in ureter development and pathogenesis of hydroureter and hydronephrosis remains unknown. Here, we show that ZEB2 is expressed in the developing ureteral mesenchymal cells, and deletion of ZEB2 in ureteral mesenchymal cells leads to ureteral smooth muscle cell loss, which is replaced by tunica adventitia cells causing hydroureter and hydronephrosis phenotype. Hence, our work not only demonstrates the critical role of ZEB2 in ureter development but also provides molecular mechanisms of urinary tract anomalies in MWS patients.