Kidney Week

Abstract: TH-PO0550

Loss of Slit2 in the PAX2+ Progenitor Cells Causes the Congenital Anomalies of the Kidney and Urinary Tract Phenotype in Mice

Session Information

• Development, Stem Cells, and Regenerative Medicine
  November 06, 2025 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Development, Stem Cells, and Regenerative Medicine

• 600 Development, Stem Cells, and Regenerative Medicine

Authors

• Pattam, Harshita, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Harshita Pattam

• Milo Rasouly, Hila, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Hila Milo Rasouly, MSc, PhD

• Ganesh, Anya S, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Anya S Ganesh

• Yan, Kun, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Kun Yan

• Chandiri, Sarayu, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Sarayu Chandiri

• Sharma, Richa, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Richa Sharma, PhD

• Kumar, Sudhir, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Sudhir Kumar, PhD

• Lu, Weining, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts, United States

Weining Lu, MD, MS, FASN

Background

Congenital anomalies of the kidney and urinary tract (CAKUT) account for 2-3% of all birth defects and are a major cause of chronic kidney disease (CKD) and kidney failure in children and young adults under 40 years old. Despite the high incidence of CKD in children with CAKUT, the pathogenesis of CAKUT remains largely unclear. SLIT2 and ROBO2 play essential roles in ureteric bud outgrowth, kidney and urinary tract development, and mutations in either SLIT2 or ROBO2 have been identified in CAKUT patients. However, the cell-specific roles of SLIT2 and ROBO2 during kidney and urinary tract development, as well as the pathogenesis of CAKUT, are not well understood.

Methods

We performed immunostaining analysis of SLIT2/ROBO2 protein expression in the developing mouse kidney and ureter. We generated Slit2 and Robo2 conditional knockout mice using Pax2-Cre, which is expressed in the early nephrogenic zone, including the ureteric bud and cap mesenchyme (i.e., Slit2^flox/flox;Pax2-Cre⁺ or Slit2 cKO, and Robo2^flox/flox;Pax2-Cre⁺ or Robo2 cKO). We analyzed the kidney and urinary tract phenotypes in Slit2 cKO and Robo2 cKO mice and their wild-type littermate by gross and histological examinations. Cellular and molecular phenotypes of the urothelial and ureteral mesenchyme were studied using cell-specific markers.

Results

We found that SLIT2 and ROBO2 are expressed in the early nephrogenic zone. Deletion of Slit2 using Pax2Cre leads to hydronephrosis and early mortality after birth. However, deletion of Robo2 using Pax2Cre has no discernible CAKUT phenotype in mice. At the histological level, Slit2 cKO mice develop a duplex kidney, hydroureter, and hydronephrosis, accompanied by a low nephron number at birth. Cell-specific marker analysis showed that Slit2 cKO mice did not develop normal urothelial and ureteral smooth muscle cells at E14.5 and P0.

Conclusion

Our results demonstrate that SLIT2, but not ROBO2, is essential for the development of PAX2+ progenitor cells. Loss of SLIT2 in PAX2+ progenitor cells leads to a CAKUT and obstructive uropathy phenotype in mice.

Funding

• NIDDK Support

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.2025h6eknd3w