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Updated: Jul 23, 2025
Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis
Published on: March 11, 2017
miR-32-5p induces hepatic steatosis and hyperlipidemia by triggering de novo lipogenesis
Ya-Di Wang1, Liang-Liang Wu2, Yun-Ni Mai1
1The First Affiliated Hospital, Department of Metabolism and Endocrinology, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China.
Background And Objectives:
MicroRNA-dependent regulation of hepatic lipid metabolism has been recognized recently as a key pathological mechanism contributing to the development of NAFLD. However, whether miR-32-5p (miR-32) plays a role in lipid metabolism or contributes to NAFLD remains unclear.
Methods And Results:
A marked increase in miR-32 expression was observed in liver samples from patients and mice with NAFLD, as well as in palmitate-induced hepatocytes. Hepatocyte-specific miR-32 knockout (miR-32-HKO) dramatically ameliorated hepatic steatosis and metabolic disorders in high-fat diet-fed mice. Conversely, hepatic miR-32 overexpression markedly exacerbated the progression of these abnormalities. Further, combinational analysis of transcriptomics and lipidomics suggested that miR-32 was a key trigger for de novo lipogenesis in the liver. Mechanistically, RNA sequencing, luciferase assay and adenovirus-mediated downstream gene rescue assay demonstrated that miR-32 directly bound to insulin-induced gene 1 (INSIG1) and subsequently activated sterol regulatory element binding protein-mediated lipogenic gene programs, thereby promoting hepatic lipid accumulation and metabolic disorders. Notably, pharmacological administration of miR-32 antagonist significantly inhibited palmitate-induced triglyceride deposition in hepatocytes and markedly mitigated hepatic steatosis and metabolic abnormalities in obesity-associated NAFLD mice.
Conclusion:
miR-32 is an important checkpoint for lipogenesis in the liver, and targeting miR-32 could be a promising therapeutic approach for NAFLD treatment.
Insights
MicroRNA-32 (miR-32) promotes liver fat accumulation in non-alcoholic fatty liver disease (NAFLD). Targeting miR-32 offers a potential therapeutic strategy for NAFLD treatment.
Area of Science:
- Hepatology
- Molecular Biology
- Metabolic Diseases
Background:
- MicroRNA-mediated regulation of hepatic lipid metabolism is crucial in non-alcoholic fatty liver disease (NAFLD) pathogenesis.
- The specific role of miR-32-5p (miR-32) in lipid metabolism and NAFLD development was previously unclear.
Purpose of the Study:
- To investigate the role of miR-32 in hepatic lipid metabolism and its contribution to NAFLD.
- To explore miR-32 as a potential therapeutic target for NAFLD.
Main Methods:
- Analysis of miR-32 expression in human and mouse NAFLD liver samples and hepatocytes.
- Generation of hepatocyte-specific miR-32 knockout (miR-32-HKO) and miR-32 overexpression mouse models.
- Transcriptomic and lipidomic analyses.
- RNA sequencing, luciferase assays, and gene rescue experiments.
- Administration of miR-32 antagonists in vitro and in vivo.
Main Results:
- miR-32 expression was significantly increased in NAFLD liver samples and palmitate-treated hepatocytes.
- miR-32-HKO ameliorated hepatic steatosis and metabolic disorders in mice fed a high-fat diet.
- miR-32 overexpression exacerbated NAFLD progression.
- miR-32 directly targets INSIG1, activating SREBP-mediated lipogenesis and promoting hepatic lipid accumulation.
- miR-32 antagonists reduced lipid deposition and mitigated NAFLD phenotypes.
Conclusions:
- miR-32 acts as a critical regulator of hepatic lipogenesis.
- Targeting miR-32 presents a promising therapeutic avenue for treating NAFLD.
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