OBJECTIVE: To investigate the influence of Estradial (E(2)) at physiological concentration on mRNA expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α(HIF-α1) in bovine retinal vascular endothelial cells (BRECs) under different oxygen conditions. METHODS: The mRNA expression of VEGF, HIF-1α in BRECs was studied by quantitative reverse-transcription PCR (qRT-PCR), and protein levels were assayed by Western Blot. Different concentrations of E(2) (10(-12), 10(-10), 10(-8) mol/l) and estrogen receptor antagonist Tamoxifen (10(-7) mol/l) were added into the cell culture medium of different groups, while the phosphate-buffered saline (PBS) was added in the control group instead. Culture conditions were set to be under normoxia and hypoxia. The results of each group were detected after 8 hours and 24 hours. RESULTS: (1) Under hypoxia, gene expression of VEGF, HIF-1α in BRECs increased more than that of the control group (P < 0.05). There is evident positive correlation between the mRNA and protein levels of VEGF and HIF-1α (r = 0.82). (2) Treated with 10(-8) mol/l E(2,) the expression of VEGF mRNA was increased in a time-dependent manner (P < 0.05). Treated with the indicated to concentrations of E(2) (10(-12 ∼ -8) mol/l) under normoxia for twenty-four hours, the mRNA expression of VEGF in BRECs was increased in a dose-dependent manner (P < 0.05), whereas E(2) did not influence the mRNA expression of HIF-1α (P > 0.05). (3) Under hypoxia , E(2) reduced the mRNA and protein levels of HIF-1α and VEGF in a concentration-dependent manner (P < 0.05), and the decrease developed in a time-dependent manner (P < 0.05). (4) An overdose of tamoxifen (10(-7) mol/l) reversed the effect of E(2) (10(-8) mol/l) (P < 0.05). CONCLUSIONS: E(2) increases the gene expression of VEGF in BRECs under normoxia, whereas E(2) reduces the gene expression of VEGF in BRECs through HIF-1α under hypoxic conditions in a dose-dependent and time-dependent manner. The contrasting effect of E(2) on mRNA expression of VEGF may play a prophylactic role in retinopathy of prematurity (ROP).
OBJECTIVE: To investigate the influence of Estradial (E(2)) at physiological concentration on mRNA expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α(HIF-α1) in bovine retinal vascular endothelial cells (BRECs) under different oxygen conditions. METHODS: The mRNA expression of VEGF, HIF-1α in BRECs was studied by quantitative reverse-transcription PCR (qRT-PCR), and protein levels were assayed by Western Blot. Different concentrations of E(2) (10(-12), 10(-10), 10(-8) mol/l) and estrogen receptor antagonist Tamoxifen (10(-7) mol/l) were added into the cell culture medium of different groups, while the phosphate-buffered saline (PBS) was added in the control group instead. Culture conditions were set to be under normoxia and hypoxia. The results of each group were detected after 8 hours and 24 hours. RESULTS: (1) Under hypoxia, gene expression of VEGF, HIF-1α in BRECs increased more than that of the control group (P < 0.05). There is evident positive correlation between the mRNA and protein levels of VEGF and HIF-1α (r = 0.82). (2) Treated with 10(-8) mol/l E(2,) the expression of VEGF mRNA was increased in a time-dependent manner (P < 0.05). Treated with the indicated to concentrations of E(2) (10(-12 ∼ -8) mol/l) under normoxia for twenty-four hours, the mRNA expression of VEGF in BRECs was increased in a dose-dependent manner (P < 0.05), whereas E(2) did not influence the mRNA expression of HIF-1α (P > 0.05). (3) Under hypoxia , E(2) reduced the mRNA and protein levels of HIF-1α and VEGF in a concentration-dependent manner (P < 0.05), and the decrease developed in a time-dependent manner (P < 0.05). (4) An overdose of tamoxifen (10(-7) mol/l) reversed the effect of E(2) (10(-8) mol/l) (P < 0.05). CONCLUSIONS: E(2) increases the gene expression of VEGF in BRECs under normoxia, whereas E(2) reduces the gene expression of VEGF in BRECs through HIF-1α under hypoxic conditions in a dose-dependent and time-dependent manner. The contrasting effect of E(2) on mRNA expression of VEGF may play a prophylactic role in retinopathy of prematurity (ROP).
Authors: I Suzuma; M Mandai; H Takagi; K Suzuma; A Otani; H Oh; K Kobayashi; Y Honda Journal: Invest Ophthalmol Vis Sci Date: 1999-08 Impact factor: 4.799
Authors: S Yamagishi; T Kawakami; H Fujimori; H Yonekura; N Tanaka; Y Yamamoto; H Urayama; Y Watanabe; H Yamamoto Journal: Microvasc Res Date: 1999-05 Impact factor: 3.514
Authors: J McLaren; A Prentice; D S Charnock-Jones; S A Millican; K H Müller; A M Sharkey; S K Smith Journal: J Clin Invest Date: 1996-07-15 Impact factor: 14.808