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CircMAP3K4 Suppresses H2O2-Induced Human Lens Epithelial Cell Injury by miR-630/ERCC6 Axis in Age-Related Cataract
Fenghua Cui1, Zhonghua Sun1, Xueyan Zhang1
1Department of Ophthalmology, the Jinan Second People's Hospital, Jinan City, Shandong, China.
Background:
Dysregulated circular RNAs (circRNAs) is involved in the pathogenesis of age-related cataract (ARC). Here, this study aimed to explore the function and mechanism of circMAP3K4 in ARC.
Methods:
Human lens epithelial cells were exposed to hydrogen peroxide (H2O2) for functional experiments. qRT-PCR and western blotting analyses were used for the expression detection of genes and proteins. Cell proliferation was tested using cell counting kit-8 and EdU. Flow cytometry was applied to analyze cell apoptosis and cell cycle. The oxidative stress was evaluated by detecting the production of malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD). The target relationship between miR-630 and circMAP3K4 or Excision repair cross-complementing group 6 (ERCC6) was analyzed by dual-luciferase reporter assay and RIP assay.
Results:
CircMAP3K4 was lowly expressed in ARC patients and H2O2-induced HLECs. Functionally, forced expression of circMAP3K4 protected HLECs against H2O2-evoked proliferation inhibition, cell cycle arrest and the promotion of cell apoptosis and oxidative stress. Mechanistically, circMAP3K4 acted as a sponge for miR-630 to regulate the expression of its target ERCC6. MiR-630 was highly expressed while ERCC6 was lowly expressed in ARC patients and H2O2-induced HLECs. Up-regulation of miR-630 could reverse the protective effects of circMAP3K4 on HLECs under H2O2 treatment. In addition, inhibition of miR-630 suppressed H2O2-induced HLEC injury, which was abolished by ERCC6 silencing.
Conclusion:
Forced expression of circMAP3K4 protected HLECs against H2O2-evoked apoptotic and oxidative injury via miR-630/ERCC6 axis, suggesting that circMAP3K4 may function as a potential therapeutic target for ARC.
Insights
CircularMAP3K4 (circMAP3K4) protects against age-related cataract (ARC) by regulating miR-630 and ERCC6. Upregulating circMAP3K4 offers a potential therapeutic strategy for ARC by mitigating oxidative stress and apoptosis.
Area of Science:
- Ophthalmology
- Molecular Biology
- Genetics
Background:
- Dysregulated circular RNAs (circRNAs) are implicated in the pathogenesis of age-related cataract (ARC).
- CircularMAP3K4 (circMAP3K4) has emerged as a potential player in ARC development.
- Understanding the specific role of circMAP3K4 in ARC is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the function and molecular mechanism of circMAP3K4 in the context of age-related cataract (ARC).
- To explore the potential of circMAP3K4 as a therapeutic target for ARC.
Main Methods:
- Human lens epithelial cells (HLECs) were subjected to hydrogen peroxide (H2O2) treatment to mimic ARC conditions.
- Quantitative real-time PCR (qRT-PCR) and western blotting were employed to assess gene and protein expression.
- Cell proliferation, apoptosis, and cell cycle progression were analyzed using CCK-8, EdU, and flow cytometry.
- Oxidative stress markers including malondialdehyde (MDA), reactive oxygen species (ROS), and superoxide dismutase (SOD) were measured.
- Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were utilized to confirm the interaction between circMAP3K4, miR-630, and Excision repair cross-complementing group 6 (ERCC6).
Main Results:
- CircMAP3K4 expression was found to be downregulated in ARC patients and H2O2-treated HLECs.
- Overexpression of circMAP3K4 conferred protection to HLECs against H2O2-induced proliferation inhibition, cell cycle arrest, apoptosis, and oxidative stress.
- Mechanistically, circMAP3K4 functions as a molecular sponge for miR-630, thereby regulating the expression of its target gene, ERCC6.
- MiR-630 was upregulated, while ERCC6 was downregulated in ARC patients and H2O2-treated HLECs.
- The protective effects of circMAP3K4 were reversed by miR-630 upregulation and mimicked by ERCC6 silencing, indicating the involvement of the miR-630/ERCC6 axis.
Conclusions:
- Forced expression of circMAP3K4 protects human lens epithelial cells against oxidative and apoptotic injury induced by H2O2 through the miR-630/ERCC6 pathway.
- CircMAP3K4 demonstrates potential as a therapeutic target for age-related cataract (ARC).
