Molinari Claudio, Uberti Francesca, Grossini Elena, Vacca Giovanni, Carda Stefano, Invernizzi Marco, Cisari Carlo
Department of Clinical and Experimental Medicine, University of Eastern Piedmont, Novara, Italy.
Cell Physiol Biochem. 2011;27(6):661-8. doi: 10.1159/000330075. Epub 2011 Jun 17.
Recently, 1α,25-dihydroxycholecalciferol (vitD) has received increasing interest for its effects on many tissues and organs other than bone. A number of experimental studies have shown that vitD may have an important role in modifying risk for cardiovascular disease.
This study was planned to test the effects of vitD on endothelial nitric oxide (NO) production and to study the intracellular pathways leading to NO release.
In human umbilical vein endothelial cells (HUVEC) cultures the effects of vitD on NO production and p38, Akt, ERK and eNOS phosphorylations were examined in absence or in presence of the NO synthase inhibitor L-NAME and protein kinases specific inhibitors SB203580, wortmannin and UO126.
VitD caused a concentration-dependent increase in NO production. The maximum effect was observed at a concentration of 1 nM and the optimal time of stimulation was 1 min. Effects induced by vitD were abolished by L-NAME and by pre-treatment with protein kinases inhibitors. To verify the effective involvement of vitD receptor (VDR) in the action mechanism of vitD, experiments were repeated in presence of the specific VDR ligands ZK159222 and ZK191784.
The results of this study demonstrate that vitD can induce a significant increase in endothelial NO production. VitD interaction with VDR caused the phosphorylation of p38, AKT and ERK leading to eNOS activation.
最近，1α,25 - 二羟胆钙化醇（维生素D）因其对骨骼以外的许多组织和器官的作用而受到越来越多的关注。大量实验研究表明，维生素D可能在改变心血管疾病风险方面发挥重要作用。
本研究旨在测试维生素D对内皮一氧化氮（NO）生成的影响，并研究导致NO释放的细胞内途径。
在人脐静脉内皮细胞（HUVEC）培养物中，在不存在或存在NO合酶抑制剂L - NAME以及蛋白激酶特异性抑制剂SB203580、渥曼青霉素和UO126的情况下，检测维生素D对NO生成以及p38、Akt、ERK和eNOS磷酸化的影响。
维生素D导致NO生成呈浓度依赖性增加。在浓度为1 nM时观察到最大效应，最佳刺激时间为1分钟。L - NAME和用蛋白激酶抑制剂预处理可消除维生素D诱导的效应。为了验证维生素D受体（VDR）在维生素D作用机制中的有效参与，在存在特异性VDR配体ZK159222和ZK191784的情况下重复实验。
本研究结果表明，维生素D可诱导内皮NO生成显著增加。维生素D与VDR的相互作用导致p38、AKT和ERK磷酸化，从而导致eNOS激活。
