MiR-18b suppresses high-glucose-induced proliferation in HRECs by targeting IGF-1/IGF1R signaling pathways.

MicroRNAs (miRNAs) are important for the proliferation of endothelial cells and have been shown to be involved in diabetic retinopathy (DR). In previous study, we found that miRNAs might play a critical role in hyperglycemia-induced endothelial cell proliferation based on miRNA expression profiling. Here, the roles of microRNA-18b (miR-18b) in the proliferation of human retinal endothelial cells (HRECs) were investigated in an in vitro model of HRECs grown in high glucose. We identified that levels of miR-18b were decreased in high-glucose-induced HRECs, compared with those in cells incubated in normal glucose. However, the reduction of miR-18b up-regulated vascular endothelial growth factor (VEGF) secretion and promoted effects on in vitro proliferation of HRECs. Mechanistically, insulin growth factor-1 (IGF-1) was identified as a target of miR-18b. IGF-1 simulation could antagonize the effect induced by miR-18b up-regulation, promoting cell proliferation and increasing VEGF production. In contrast, the opposite results were observed with silencing IGF-1, which was consistent with the effects of miR-18b overexpression. MiR-18b exerted its function on VEGF synthesis and cell proliferation by suppressing the IGF-1/insulin growth factor-1 receptor (IGF1R) pathway, consequently inhibiting the downstream phosphorylation of Akt, MEK, and ERK. Hence, this may provide a new insight into understanding the mechanism of DR pathogenesis, as well as a potential therapeutic target for proliferative DR.

[Management of primary angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens implantation].

OBJECTIVE: To evaluate the efficacy and safety of phacoemulsification with foldable posterior chamber intraocular lens(PC-IOL) implantation in the management of acute or chronic primary angle-closure glaucoma(APACG or CPACG) with cataract. METHODS: Twenty-six cases(28 eyes) with simple cataract and 60 cases(70 eyes)of PACG with cataract, including 14 eyes of preclinical APACG, 29 eyes of paroxysmal APACG, 27 eyes of CPACG. Visual acuity distributed from hand movement to 0.8. Phacoemulsification and intraocular lens implantation were performed and patients were followed up for(8.5+/-4.5) months. RESULT: In simple cataract group, postoperative IOP did not decrease(t=1.9201, P>0.05); in preclinical APACG group, postoperative IOP decreased (t=3.9910, P<0.01); in paroxysmal APACG group, postoperative IOP decreased (t=4.7441, P<0.01); in CPACG groups, postoperative IOP decreased (t=4.4976, P<0.01). In APACG and CPACG groups postoperative antiglaucoma medication reduced. In APACG and CPACG groups, angle of anterior chamber was widen. Preoperative central and peripheral ACD of APACG and CPACG were much less than those of postoperative. In 56 eyes of PACG, visual acuity was corrected in 48 eyes(85.7%) including 28 eyes(50%) with corrected visual acuity>0.5. CONCLUSION: The phacoemulsification with foldable posterior chamber intraocular lens implantation is beneficial for PACG with cataract, and the curative efficacy of APACG is better than that of CPACG.