Purchase this article with an account.
Mitchell A Watsky, Xiaowen Lu; Effects of 1,25 and 24,25 Vitamin D on Corneal Epithelial Migration, Proliferation, and Vitamin D Metabolizing and Catabolizing Enzymes. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):5625.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the effects on 1,25-VitD3 and 24,25-VitD3 on human corneal epithelial cell proliferation, migration, and on the vitamin D activating enzyme CYP27B1 (encodes 1,25-VitD3) and the vitamin D inactivating enzyme CYP24A1 (encodes 24,25-VitD3). We also examined the role of the vitamin D receptor (VDR) in these responses.
Human corneal epithelial cell (HCEC) proliferation was measured by reduction of MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], which corresponds to the living cell number and metabolic activity. The efficacy of Vitamin D in promoting human epithelial cell migration was tested using a scratch-wounded assay. Total RNA was isolated from the HCEC and transcript levels of VDR, CYP24A1, and CYP27B1 were assessed by qPCR. qPCR and western blot were used to detect VDR, CYP24A1, and CYP27B1 in HCEC with or without siRNA-mediated VDR silencing.
Only 24,25-VitD3 (50 nM) significantly increased HCEC proliferation and migration. CYP24A1 was detected in both human corneal primary epithelial cells and the HCEC cell line. CYP24A1, CYP27B1, and VDR mRNA and CYP27B1 and VDR protein levels were significantly increased in HCEC cultured with 1,25-VitD3 (10 nM) and 24,25-VitD3 (50 nM). CYP24A1, CYP27B1, and VDR mRNA were significantly decreased in VDR-silenced HCEC and 24,25-VitD3 increased CYP24A1 and CYP27B1 mRNA in VDR-silenced HCEC.
24,25-VitD3 stimulates HCEC proliferation and migration. 1,25-VitD3 increases VDR and CYP27B1 expression in HCEC. 24,25-VitD3 increases expression of CYP27B1 in HCEC with or without VDR silencing. 24,25-VitD3 is likely involved in HCEC regulation independent of 1,25-VitD3 or VDR.
This PDF is available to Subscribers Only