2. Academic Validation
  3. CircLDLR acts as a sponge for miR-667-5p to regulate SIRT1 expression in non-alcoholic fatty liver disease

CircLDLR acts as a sponge for miR-667-5p to regulate SIRT1 expression in non-alcoholic fatty liver disease

  • Lipids Health Dis. 2022 Nov 29;21(1):127. doi: 10.1186/s12944-022-01740-9.
Xinlu Yuan 1,  Yanyan Li 2,  Song Wen 2,  Chenglin Xu 2,  Congcong Wang 2,  Yanju He 2,  Ligang Zhou 3
Affiliations

Affiliations

  • 1 Department of Endocrinology and Metabolic Diseases, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Pudong, Shanghai, 201399, China. [email protected].
  • 2 Department of Endocrinology and Metabolic Diseases, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Pudong, Shanghai, 201399, China.
  • 3 Department of Endocrinology and Metabolic Diseases, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Pudong, Shanghai, 201399, China. [email protected].
PMID: 36443854 DOI: 10.1186/s12944-022-01740-9
Abstract

Background: Non-alcoholic fatty liver (NAFLD) is a complex Metabolic Disease characterized by fatty degeneration of hepatocytes. Circular RNAs (circRNAs) have been reported to be essential for (NAFLD progression. The potential mechanism of circRNA low-density lipoprotein receptor (circLDLR) in the NAFLD was investigated in this study.

Methods: Hepatocyte (Hepa1-6) cells treated with oleic acid/palmitic acid (OA/PA) were used as the in vitro NAFLD model, and C57BL/6 mice fed with high-fat diet (HFD) were used as the in vivo NAFLD model. The circLDLR, LDLR, and miR-667-5p expression were measured by quantitative real-time polymerase chain reaction (qRT-PCR), while the protein levels of LIGHT Chain Microtubule-Associated Protein 3 (LC3) and Sequestosome-1(p62) was examined by western blot. The circLDLR location was confirmed using RNA fluorescence in situ hybridization. Oil red O staining was carried out to measure lipid deposition in cells. The secreted levels of triglyceride (TG) and total Cholesterol (TC) were detected through Enzymatic. The existence of the circLDLR/miR-667-5p/Sirtuin 1 (SIRT1) regulatory axis was validated by applying the dual-luciferase reporter assay.

Results: The circLDLR expression showed a prominent down-regulation in OA/PA-treated Hepa1-6 cells, whereas the LDLR expression was up-regulated. Overexpression of circLDLR significantly attenuated lipid droplet accumulation in NAFLD models in vitro/vivo, reduced TG, TC, and p62 levels, and increased LC3-II levels and the amount of the green fluorescent protein (GFP)-LC3 puncta in cells. CircLDLR and SIRT1 are common targets of miR-667-5p to inhibit the TG and TC and promote the Autophagy pathway. SIRT1 knockdown reversed the effects of circLDLR overexpression.

Conclusions: CircLDLR alleviated the development of NAFLD by inducing autophagic flux while modulating the miR-667-5p/SIRT1 axis reversed its effects, suggesting that targeting circLDLR/miR-667-5p/SIRT1 axis may be a promising therapeutic strategy for NAFLD.

Keywords

Autophagy; Non-alcoholic fatty liver disease; SIRT1; circRNAs; miR-667-5p.

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