Molecular Crosstalk Between SIRT1, Wnt/β-Catenin Signaling, and Inflammatory Pathways in Renal Transplant Rejection: Role of miRNAs, lncRNAs, IL-1, IL-6, and Tubulointerstitial Inflammation.

Background/Objectives: This study aimed to evaluate the relationship between sirtuin family members (SIRT1, SIRT3, and SIRT6) and Wnt/β-catenin pathways with inflammation during the rejection process following kidney transplantation, as well as to explore their potential roles as candidate biomarkers. Materials and Methods: Blood samples were collected from 35 kidney transplant rejection patients and 30 healthy controls. The gene expression levels of SIRT1, SIRT3, SIRT6, and Wnt/β-catenin pathway components were measured using real-time PCR, and miRNA and lncRNA expression levels were analyzed. Statistical analyses were performed using SPSS version 23. Results: Significant alterations in SIRT1, SIRT3, and SIRT6 expression levels were observed in rejection patients, suggesting their potential role in disease pathogenesis and as therapeutic biomarkers. Key altered genes included hsa-miR-34c-1, hsa-miR-122b-5b, MALAT1, HOTAIR, LINC00473, TUG, PVT1, SIRT1, SIRT3, SIRT6, WNT1, TCF-LEF, LRP, AXIN1, IL1B, IL6, and IFNB1, all showing significant changes. However, no significant differences were found for miRNAs such as hsa-miR-21-2, hsa-miR-155-5p, and hsa-miR-200b-3p. SIRT1 expression was significantly decreased in the cellular rejection group, with a more pronounced reduction in these patients. Significant differences in SIRT1 expression were observed with interstitial inflammation and glomerulitis. Increased inflammation severity correlated with decreased SIRT1 and increased TCF-LEF, TUG, and miR-21 levels, while tubulitis severity was associated with elevated TCF-LEF and miR-155 expression. Conclusions: Along with the activation of Wnt/β-catenin pathways and increased levels of certain miRNAs and long non-coding RNAs (lncRNAs) associated with TCF-LEF transcription factors, the observed decrease in SIRT1 expression may be related to the severity of inflammation and tubulitis. These findings suggest that SIRT1, Wnt/β-catenin pathways, and non-coding RNAs play a role in the rejection process following kidney transplantation and could be considered as potential biomarkers or therapeutic target candidates for future research.