(A) The binding sites between miR-19b and MEG3 are shown. (B) The targeting relationship between miR-19b and MEG3 was identified by luciferase reporter assay in cells transfected with miR-19b mimics, miR-19b inhibitor or NCs. (C) The transfection efficiency of pcDNA3.1-MEG3 and si-MEG3 in hRMECs was validated by qRT-PCR. (D) Expression of miR-19b was determined by qRT-PCR in hRMECs transfected with pcDNA3.1-MEG3 and si-MEG3. (E) HRMECs were transfected with pcDNA3.1-MEG3, miR-19b mimics, pcDNA3.1-MEG3 and miR-19b mimics, or NC and then cultured in high glucose conditions. The viability of HG-induced hRMECs was evaluated by the MTT assay. (F) The protein levels of the proliferation-related molecules CNA, Cyclin D1 and Cyclin E1 in HG-induced hRMECs were determined by Western blotting assay. (G) The activity of caspase-3/7 in HG-induced hRMECs was measured by commercial kits. (H) The cell apoptosis rate in HG-induced hRMECs was evaluated by flow cytometry analysis. (I) The levels of the apoptosis-related proteins cleaved caspase-3, Bcl-2 and Bax in HG-induced hRMECs were measured by Western blotting. (J and K) The secretion of inflammatory factors (TNF-α, IL-6 and IL-1β) in HG-induced hRMECs was detected by qRT-PCR and ELISA. (L) The protein levels of the signalling pathway components SOCS6, p-JAK2, t-JAK2, p-STAT3 and t-STAT3 were detected by Western blotting; n=3, *P<0.05, **P<0.01, ***P<0.001.