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Abstract: PO2471

CircHIPK3 Aggravates Folic Acid-Induced Renal Interstitial Fibrosis by Sponging miR-30a

Session Information

Category: CKD (Non-Dialysis)

  • 2103 CKD (Non-Dialysis): Mechanisms

Authors

  • Zhou, Hua, Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, China
  • Luan, Junjun, Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, China
  • Jiao, Congcong, Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, China
Background

Renal interstitial fibrosis is a major pathological feature of end stage kidney disease and currently lacks effective treatment. CircHIPK3 is reported to participate in various diseases. However, the role of circHIPK3 in renal fibrosis is unreported. We aimed to verify whether circHIPK3 participates in the pathogenesis of renal fibrosis and its corresponding.

Methods

C57BL/6 mice were intraperitoneally injected with folic acid (FA) (250 mg/kg) for 30 days. Renal tissue samples were used for paraffin section PAS and Masson staining to confirm the occurrence of renal fibrosis. The expressions of circHIPK3, miR-30a, Transforming growth factor β (TGF-β1),Fibronectin (FN) and Collagen 1 (COL1) in kidney were detected. Those three parameters were further confirmed by immunoblotting. Then the expressions of miR-30a, TGF-β1, FN and COL-1 were detected in immortalized human tubular epithelial cells HK-2 cells overexpressed of circHIPK3 and stimulated with TGF-β1. Finally, fluorescence in situ hybridization (FISH) to measure the localization of circHIPK3 and miR-30a, and immunofluorescence was to detect the expressions of TGF-β1, FN and COL1.

Results

In mice, renal fibrosis features and expression of profibrotic FN and COL1 were increased at day 30 after peritoneal injection of FA. Renal circHIPK3 was up-regulated while miR-30a was down-downregulated in FA-induced kidney injury, as shown by qPCR and FISH. TGF-β1 expression was increased. In addition, renal circHIPK3 negatively correlated with miR-30a and kidney miR-30a also negatively correlated with TGF-β1 mRNA expression. In HK-2 cells, circHIPK3, miR-30a, and TGF-β1 co-localized in the cytoplasm on FISH and immunofluorescence staining. Importantly, transient transfection of circHIPK3 down-regulated miR-30a and up-regulated TGF-β1, FN, and COL1 assessed by qPCR and immunoblotting. Furthermore, exposure of HK-2 cells to human TGF-β1 resulted in increased circHIPK3, decreased miR-30a, and increased expression of profibrotic fibronectin and collagen l protein. Kidney biopsies from patients with chronic tubulointerstitial nephritis manifested the same directional changes of circHIPK3, miR-30a, and profibrotic proteins including TGF-β1, FN and COL l.

Conclusion

A pro-fibrotic feedback involving in circHIPK3, miR-30a, and TGF-β1 and further indicated that circHIPK3 might contribute to renal fibrosis by sponging miR-30a.

Funding

  • Government Support – Non-U.S.