Effects of microRNA-29a on retinopathy of prematurity by targeting AGT in a mouse model.

BACKGROUND: This study aimed to explore the effects of microRNA-29a (miR-29a) on retinopathy of prematurity (ROP) by targeting angiotensinogen (AGT) expression in a mouse model. METHODS: Ninety-six C57BL/6J mice were selected and divided into the normal control group (n = 12) and the oxygen-induced retinopathy (OIR) group (n = 84). All the mice in the OIR group were assigned to the following seven groups (12 mice in each group): the blank, miR-29a mimics, miR-29a inhibitors, empty plasmid, miR-29a mimics + si-AGT, miR-29a inhibitors + si-AGT and si-AGT groups. ADPase histochemical staining was conducted to detect the morphology of retinal neovascularization. H&E staining was performed to quantify retinal neovascularization. The qRT-PCR assay was applied to detect the expression levels of miR-29a and the AGT mRNA. Western blotting was used to detect the protein expressions of AGT, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), angiotensin (ANG) and angiotensin II (AngII). RESULTS: Compared with the normal control group, miR-29a expression decreased, while the AGT mRNA expression and the protein expression levels of AGT, VEGF, HGF, ANG and AngII increased, and retinal vascular density and neovascularization also increased in the OIR group. In the OIR group, compared with the blank, empty plasmid, miR-29a inhibitors and miR-29a inhibitors + si-AGT groups, miR-29a expression increased, while the AGT mRNA expression and protein expression levels of AGT, VEGF, HGF, ANG and AngII decreased, and retinal vascular density and neovascularization also decreased in the miR-29a mimics, miR-29a mimics + si-AGT and si-AGT groups. CONCLUSION: MiR-29a could inhibit retinal neovascularization to prevent the development and progression of ROP by down-regulating AGT.

Refractive status and optical components of premature babies with or without retinopathy of prematurity at 3-4 years old.

PURPOSE: To investigate the refractive status and optical components of premature babies with or without retinopathy of prematurity (ROP) at 3-4 years old, and to explore the influence of prematurity and ROP on the refractive status and optical components. METHODS: Premature babies receiving fundus examination were recruited into ROP group and non-ROP group, with age-matched full-term babies as controls. RESULTS: The incidence of myopia was the highest in ROP (3/59, 5.08%). The incidence of astigmatism was significantly different between ROP (37.29%, 22/59) and controls (17.86%, 15/84). The corneal refractive power in ROP and non-ROP was more potent compared with controls (P<0.05); corneal curvature was steeper (P<0.05); lens thickness was thinner (P<0.05); ocular axial length was shorter P<0.05). The gestational age was negatively related to corneal astigmatism and astigmatism, positively associated with vitreous thickness and axial length. The birth-weight was negatively associated with corneal astigmatism, astigmatism and corneal refractive power, positively related to corneal radius of curvature, vitreous thickness and ocular axial length. CONCLUSION: Premature babies with or without ROP are susceptible to myopia and astigmatism. ROP, prematurity and low birth-weight synergistically influence the development of refractive status and optical components, of which the prematurity and low birth-weight are more important.