1. Blocking TGF-β and β-Catenin Epithelial Crosstalk Exacerbates CKD
- Author
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Peter E. Clark, Surekha Neelisetty, Agnes B. Fogo, Marika Manolopoulou, Haichun Yang, Melanie Phillips, Ethan Lee, Raymond C. Harris, Leslie Gewin, Gautam Bhave, Lauren May, Makoto Mark Taketo, and Stellor Nlandu-Khodo
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Cell type ,medicine.medical_treatment ,030232 urology & nephrology ,Biology ,03 medical and health sciences ,0302 clinical medicine ,Mediator ,Transforming Growth Factor beta ,Fibrosis ,Internal medicine ,medicine ,Humans ,Renal Insufficiency, Chronic ,Receptor ,beta Catenin ,Growth factor ,Wnt signaling pathway ,General Medicine ,medicine.disease ,Cell biology ,Basic Research ,030104 developmental biology ,Endocrinology ,Nephrology ,Catenin ,Receptors, Transforming Growth Factor beta ,Transforming growth factor - Abstract
The TGF-β and Wnt/β-catenin pathways have important roles in modulating CKD, but how these growth factors affect the epithelial response to CKD is not well studied. TGF-β has strong profibrotic effects, but this pleiotropic factor has many different cellular effects depending on the target cell type. To investigate how TGF-β signaling in the proximal tubule, a key target and mediator of CKD, alters the response to CKD, we injured mice lacking the TGF-β type 2 receptor specifically in this epithelial segment. Compared with littermate controls, mice lacking the proximal tubular TGF-β receptor had significantly increased tubular injury and tubulointerstitial fibrosis in two different models of CKD. RNA sequencing indicated that deleting the TGF-β receptor in proximal tubule cells modulated many growth factor pathways, but Wnt/β-catenin signaling was the pathway most affected. We validated that deleting the proximal tubular TGF-β receptor impaired β-catenin activity in vitro and in vivo. Genetically restoring β-catenin activity in proximal tubules lacking the TGF-β receptor dramatically improved the tubular response to CKD in mice. Deleting the TGF-β receptor alters many growth factors, and therefore, this ameliorated response may be a direct effect of β-catenin activity or an indirect effect of β-catenin interacting with other growth factors. In conclusion, blocking TGF-β and β-catenin crosstalk in proximal tubules exacerbates tubular injury in two models of CKD.
- Published
- 2017