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CircGAB1 Facilitates Podocyte Injury Through Sponging miR-346 and Activating MAPK6 in Diabetic Nephropathy
Pingyue Ma1, Yajing He1, Benyong Wang1
1Department of Nephrology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, No.261, Huansha Road, Hangzhou, Zhejiang, 310006, P. R. China.
Background:
Podocyte injury is very important process in diabetic nephropathy (DN) progression. Circular RNA (circRNA) takes part in regulating the advancement of DN. Herein, we explored the role and mechanism of circGAB1 in DN progression.
Methods:
The abundances of circGAB1, microRNA-346 (miR-346) and mitogen-activated protein kinase 6 (MAPK6) were detected by qRT-PCR in DN serum samples and podocyte HGPC. Moreover, cell viability and apoptosis were determined using CCK8 assay and flow cytometry. Also, the protein levels of MAPK6, proliferation-related markers and apoptosis-related markers were analyzed by western blot. ELISA assay was used to measure the levels of inflammatory factors, and corresponding kits were used to detect the levels of oxidative stress-related markers. The relationship between miR-346 and circGAB1 or MAPK6 was distinguished by dual-luciferase reporter assay.
Results:
CircGAB1 expression was increased in DN serum samples and HG-treated HGPC cells. CircGAB1 knockdown inhibited HG-induced apoptosis, inflammatory response and oxidative stress in HGPC cells. In terms of mechanism, circGAB1 sponged miR-346, and miR-346 targeted MAPK6. The inhibition effect of circGAB1 knockdown on HG-induced podocyte injury could be reversed by miR-346 inhibitor. Moreover, miR-346 overexpression repressed HG-induced podocyte injury by targeting MAPK6. CircGAB1 served as miR-346 sponge to positively regulate MAPK6.
Conclusion:
CircGAB1 contributed to podocyte injury through mediating miR-346/MAPK6 axis, suggesting that circGAB1 might promote DN progression.
Insights
Circular RNA GAB1 (circGAB1) exacerbates diabetic nephropathy by promoting podocyte injury. CircGAB1 targets microRNA-346 (miR-346) to upregulate mitogen-activated protein kinase 6 (MAPK6), driving disease progression.
Area of Science:
- Molecular Biology
- Cell Biology
- Pathology
Background:
- Diabetic nephropathy (DN) is a severe complication of diabetes characterized by progressive kidney damage.
- Podocyte injury is a critical event in the advancement of DN.
- Circular RNAs (circRNAs) are emerging as key regulators in the pathogenesis of DN.
Purpose of the Study:
- To investigate the role and underlying mechanism of circGAB1 in the progression of diabetic nephropathy.
- To elucidate the interaction between circGAB1, microRNA-346 (miR-346), and mitogen-activated protein kinase 6 (MAPK6) in podocyte injury.
Main Methods:
- Quantitative real-time PCR (qRT-PCR) to measure circGAB1, miR-346, and MAPK6 expression.
- Cell viability (CCK8 assay) and apoptosis (flow cytometry) assays.
- Western blot for protein analysis, ELISA for inflammatory factors, and oxidative stress marker detection.
- Dual-luciferase reporter assay to confirm molecular interactions.
Main Results:
- CircGAB1 expression was significantly upregulated in DN serum samples and high glucose-treated podocytes.
- Knockdown of circGAB1 attenuated high glucose-induced podocyte apoptosis, inflammation, and oxidative stress.
- CircGAB1 acted as a molecular sponge for miR-346, inhibiting its function, and miR-346 directly targeted MAPK6.
- Overexpression of miR-346 or inhibition of circGAB1 protected against podocyte injury, while a miR-346 inhibitor reversed the protective effects of circGAB1 knockdown.
Conclusions:
- CircGAB1 promotes podocyte injury and potentially diabetic nephropathy progression by modulating the miR-346/MAPK6 axis.
- CircGAB1 serves as a crucial regulator in the pathogenesis of DN, highlighting its potential as a therapeutic target.
