Objective: Diabetic retinopathy (DR) is one of the most severe and common complications of diabetes mellitus. The present study aimed to investigate the molecular mechanism of MEG3, miR-19b and SOCS6 in human retinal microvascular endothelial cells (hRMECs) under high glucose conditions.
Methods: HRMECs were cultured in 5 or 30 mM D-glucose medium. qRT-PCR and Western blotting were used to determine the mRNA expression and protein levels. MTT assay and flow cytometry analysis were performed to detect the viability and apoptosis of hRMECs, respectively. TNF-α, IL-6 and IL-1β levels in cell supernatants were detected by ELISA. The activity of caspase-3/7 was also determined. A luciferase reporter assay was performed to confirm the targeting relationship between miR-19b and SOCS6, as well as MEG3 and miR-19b.
Results: Our study demonstrated that miR-19b was increased and SOCS6 was decreased in HG-induced hRMECs. Knockdown of SOCS6 inhibited cell viability and reversed the promotion of cell viability induced by knockdown of miR-19b. Additionally, miR-19b directly targeted and negatively regulated SOCS6. Moreover, miR-19b promoted the cell apoptosis rate and caspase-3/7 activity and increased inflammatory factors through the SOCS6-mediated JAK2/STAT3 signalling pathway. In addition, MEG3 attenuated HG-induced apoptosis of hRMECs by targeting the miR-19b/SOCS6 axis.
Conclusion: These findings indicate that MEG3 inhibited HG-induced apoptosis and inflammation by regulating the miR-19b/SOCS6 axis through the JAK2/STAT3 signalling pathway in hRMECs. Thus, these findings might provide a new target for the treatment of DR.
Keywords: DR; MEG3; SOCS6; hRMECs; miR-19b.
© 2020 The Author(s).