Transforming growth factor-β receptor types I and II are expressed in renal tubules and are increased after chronic unilateral ureteral obstruction

Document Type

Journal Article

Publication Date



Life Sciences








Kidney; TGF-β receptors; Unilateral ureteral obstruction


Transforming growth factor-β (TGF-β) is a profibrotic cytokine which has been implicated in the renal fibrosis which follows unilateral ureteral obstruction (UUO) in the rat. TGF-β receptor types I (TGF-RI) and TGF-β. We sought to determine if TGF-Ri and TGF-RII are found in the kidney, and if their expression is changed as a result of UUO. Polymerase chain reaction (PCR) was used to determine expression of mRNA for TGF-RI and TGF-RII in the kidney. Immunoperoxidase was used to localize and quantify the expression of these receptors at 3, 7, 14, 21 and 28 days after UUO, and in sham-operated animals. Expression of mRNA for TGF-RI and TGF-RII was demonstrated in sham operated, obstructed ad contralateral unobstructed kidneys using PCR. Using immunoperoxidase, a uniform kidneys, whereas medullary tubules showed a patchy TGF-RI distribution and no TGF-RII staining. After UUO, an increased tubular expression of TGF-RI and TGF-RII was noted in both obstructed and contralateral kidneys compared to sham operated kidneys. No staining for either TGF-RI or TGF- RII was noted in glomeruli, vasculature or intestinal cells. TGF-β receptors I and II were found exclusively in renal tubules and were shown to increase in both the obstructed and contralateral kidneys relative to sham operated animals. Upregulation of TGF-β receptors in both kidneys suggest that TGF-β may contribute to the fibrotic response in the obstructed kidney and the hypertrophic response of the contralateral kidney.