OBJECTIVETo study possible influences of 1,25(OH)(2)D(3) on endothelial cell proliferation, apoptosis and endothelial nitric oxide synthase (eNOS) expression of aorta in apolipoprotein E-deficient (apoE(-/-)) mice and to explore the relationship between vitamin D and atherosclerosis.

METHODEndothelial cell of aorta in apoE(-/-) mice were isolated and cultured, and the influence of 1,25(OH)(2)D(3) on endothelial cell proliferation were observed by MTT, apoptosis of cells were quantitated by terminal deoxynucleotidyl transferase mediated dUTP nick end labelling, Bcl-2 mRNA, fas mRNA and eNOS mRNA was detected by reverse transcription-polymerase chain reaction.

RESULTEndothelial cell proliferation rate of aorta did not significantly change in the two control groups (0.162 ± 0.031 vs. 0.158 ± 0.006, P > 0.05). Compared with control groups, 1,25(OH)(2)D(3) stimulated endothelial cell proliferation of aorta (P < 0.05), but endothelial cell proliferation rate did not significantly change in different 1,25(OH)(2)D(3) concentration groups [1,25(OH)(2)D(3) concentration: 10(-4)mol/L, 10(-5) mol/L, 10(-6) mol/L, 10(-7) mol/L, 10(-8) mol/L, endothelial cell proliferation rate: 0.189 ± 0.013 vs. 0.285 ± 0.011 vs. 0.296 ± 0.026 vs. 0.284 ± 0.017 vs. 0.233 ± 0.010, P > 0.05]. 1,25(OH)(2)D(3) research concentration as chosen as 10(-6) mol/L. In 1,25(OH)(2)D(3) 10(-6) mol/L group, the expression of Bcl-2, eNOS mRNA was significantly increased (0.78 ± 0.16 vs. 0.46 ± 0.21 vs. 0.42 ± 0.17, 0.56 ± 0.16 vs. 0.39 ± 0.13 vs. 0.35 ± 0.11, 0.46 ± 0.2 vs. 10.42 ± 0.17 vs. 0.78 ± 0.16, 0.79 ± 0.21 vs. 0.81 ± 0.20 vs. 0.43 ± 0.12), apoptotic index, Fas mRNA was significantly decreased (15.14 ± 3.19 vs. 18.94 ± 4.22 vs. 19.27 ± 4.58, 0.43 ± 0.12 vs.0.79 ± 0.21 vs. 0.81 ± 0.20)(P < 0.05). The quantity of eNOS gene expression was inversely associated with apoptosis index and Fas mRNA, was positively associated with Bcl-2 mRNA (r = -0.676, -0.758, 0.762, P < 0.01).

CONCLUSION1,25(OH)(2)D(3) stimulated endothelial cell proliferation, inhibited apoptosis and increased eNOS expression of aorta in apoE(-/-) mice. These results may deepen understanding of the pathogenesis of atherosclerosis.

Animals ; Aorta ; metabolism ; Apolipoproteins E ; deficiency ; Apoptosis ; drug effects ; Calcitriol ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Endothelial Cells ; metabolism ; Female ; Male ; Mice ; Nitric Oxide Synthase Type III ; metabolism ; RNA, Messenger ; genetics

Prostaglandin E2(PGE2), a major product of cyclooxygenase, has been implicated in modulating angiogenesis, vascular function, and inflammatory processes, but the underlying mechanism is not clearly elucidated. We here investigated the molecular mechanism by which PGE 2 regulates angiogenesis. Treatment of human umbilical vein endothelial cells (HUVEC) with PGE 2 increased angiogenesis. PGE 2 increased phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), eNOS activity, and nitric oxide (NO) production by the activation of cAMP-dependent protein kinase (PKA) and phosphatidylinositol 3-kinase (PI3K). Dibutyryl cAMP (DB-cAMP) mimicked the role of PGE 2 in angiogenesis and the signaling pathway, suggesting that cAMP is a down-stream mediator of PGE 2. Furthermore, PGE 2 increased endothelial cell sprouting from normal murine aortic segments, but not from eNOS-deficient ones, on Matrigel. The angiogenic effects of PGE 2 were inhibited by the inhibitors of PKA, PI3K, eNOS, and soluble guanylate cyclase, but not by phospholipase C inhibitor. These results clearly show that PGE 2 increased angiogenesis by activating the NO/cGMP signaling pathway through PKA/PI3K/Akt-dependent increase in eNOS activity.
1-Phosphatidylinositol 3-Kinase/antagonists & inhibitors ; Animals ; Aorta ; Cell Movement/drug effects ; Cell Proliferation/drug effects ; Cyclic AMP/metabolism/pharmacology ; Cyclic GMP/biosynthesis/*metabolism ; Dinoprostone/*pharmacology ; Endothelial Cells/*drug effects/metabolism ; Enzyme Inhibitors/pharmacology ; Humans ; Mice ; Mice, Knockout ; Neovascularization, Physiologic/*drug effects ; Nitric Oxide/biosynthesis/*metabolism ; Nitric Oxide Synthase Type III/deficiency/metabolism ; Phosphorylation/drug effects ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Rats, Sprague-Dawley ; Research Support, Non-U.S. Gov't ; Signal Transduction/*drug effects ; Umbilical Veins/cytology/*drug effects/metabolism