Renal tubular cell binding of β-catenin to TCF1 versus FoxO1 is associated with chronic interstitial fibrosis in transplanted kidneys.
Am J Transplant 2021;
21:727-739. [PMID:
32870598 DOI:
10.1111/ajt.16287]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 07/05/2020] [Accepted: 07/06/2020] [Indexed: 01/25/2023]
Abstract
β-Catenin is an important co-factor which binds multiple transcriptional molecules and mediates fibrogenic signaling pathways. Its role in kidney transplantation is unknown. We quantified binding of β-catenin within renal tubular epithelial cells to transcription factors, TCF1 and FoxO1, using a proximity ligation assay in 240 transplanted kidneys, and evaluated their pathological and clinical outcomes. β-Catenin/FoxO1 binding in 1-month protocol biopsies inversely correlated with contemporaneous chronic fibrosis, subsequent inflammation. and inflammatory fibrosis (P < .001). The relative binding of β-catenin/TCF1 versus β-catenin/FoxO1 (TF ratio) was the optimal biomarker, and abnormal in diverse fibrotic transplant diseases. A high 1-month TF ratio was followed by greater tubular atrophy and interstitial fibrosis scores, cortical inflammation, renal impairment, and proteinuria at 1 year (n = 131, all P < .001). The TF ratio was associated with reduced eGFR (AUC 0.817), mild fibrosis (AUC 0.717), and moderate fibrosis (AUC 0.769) using receiver operating characteristic analysis. An independent validation cohort (n = 76) confirmed 1-month TF was associated with 12-month moderate fibrosis (15.8% vs. 2.6%, P = .047), however, not with other outcomes or 10-year graft survival, which limits generalizabilty of these findings. In summary, differential binding of β-catenin to TCF1 rather than FoxO1 in renal tubular cells was associated with the fibrogenic response in transplanted kidneys.
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