ABSTRACT
Objective:We applied a hypoxia-induced model of human fetal retinal microvascular endothelial cell (RMEC) to study the effect of carbonic anhydrase 9 (CA9) on cell proliferation.Methods:The eyeballs of spontaneously aborted fetuses in Guangdong Women and Children's Hospital were obtained, and the retinas were isolated. RMEC was obtained by trypsin and collagenase two-step enzyme digestion, and endothelial cells were identified by CD34. The fetal RMEC and the purchased adult RMEC were cultured in normoxic and hypoxic incubators (1%O 2+5%CO 2+94%N 2), and the expression of CA9 was detected by qPCR and Western blot. After knocking down the CA9 by small interference RNA technique, the cell proliferation was detected by CCK-8 method, and the cell viability was detected by CCK-8 after adding CA9 inhibitor U-104. Results:The primary RMEC was extracted successfully. Immunofluorescence staining showed the percentage of CD34 positive cells in the third-generation cells was nearly 100%. The expression of CA9 mRNA in immature fetus and adult RMEC under hypoxia culture was higher than that under normoxic culture (fetal 1% O 2 group vs. fetal 21% O 2 group: 67.80±10.31 vs. 1.00±0.04, P<0.001; adult 1% O 2 group vs. adult 21% O 2 group: 1.72±0.22 vs. 1.00±0.02, P=0.014). Western blot analysis showed significantly increased expression of CA9 in the fetal RMEC exposed to hypoxia, which aligned with the expression of CA9 mRNA. When fetal RMEC was transfected with siCA9 20 nM, the knockdown rate of CA9 was 95% ( P<0.001). CCK-8 assay showed significantly lower proliferation of fetal RMEC cells in siCA9 group compared to siNC group (0.57±0.05 vs. 0.90±0.03, P<0.001), which was reflected by the OD value. With the addition of 100 μM CA9 inhibitor U-104, the viability of fetal RMEC in the treated groupwas significantly lower than that in the untreated group (99.16%±3.82% vs. 119.10% ±1.72%, P=0.002). Conclusions:The expression of CA9 differed between adult and preterm fetus in our hypoxia-induced RMEC model. Inhibiting CA9 can inhibit the proliferation of retinal microvascular endothelial cells of preterm fetus.
ABSTRACT
Hypoxia-inducible factor-1 (HIF-1) is an essential transcription factor, which mediates the transcription of multiple target genes to adapt the body for hypoxia.Oxygen-induced retinal neovascularization (RNV) is an important pathological process of retinopathy of prematurity (ROP). By mediating the transcription of vascular endothelial growth factors, angiopoietin and platelet-derived growth factors, HIF-1 can promote RNV and then lead to ROP.Therefore, HIF-1 plays a vital role in the pathological process of ROP.In this paper, the recent research progress on the role of HIF-1 in oxygen-induced RNV was summarized in order to further the understanding of ROP pathogenesis and treatment.