Chang Jer-Ming, Kuo Mei-Chuan, Kuo Hung-Tien, Hwang Shang-Jyh, Tsai Jer-Chia, Chen Hung-Chun, Lai Yung-Hsiung
Department of Nephrology, Kaohsiung Medical University, Kaohsiung, Taiwan.
J Lab Clin Med. 2004 Jan;143(1):14-22. doi: 10.1016/j.lab.2003.08.002.
The expression of inducible nitric oxide synthase (iNOS) expression and release of nitric oxide (NO) from macrophages are markedly increased in granulomatous infections. Activation of macrophages 1alpha-hydroxylase results in an increase of 1alpha,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)]. However, the significance of this increased production is not completely understood. In this study, we analyzed 1,25(OH)(2)D(3) and NO production in patients with tuberculosis infection and hypercalcemia and used lipopolysaccharide (LPS) to stimulate RAW 264.7 cells in an attempt to assess iNOS expression and gaseous NO production regulated by 1,25(OH)(2)D(3). Peroxynitrite (OONO(-)) production and lactate dehydrogenase activity were also examined. Without additional stimulation, peripheral-blood mononuclear cells (PBMCs) from patients with tuberculosis converted more 25-hydroxyvitamin D(3) to 1,25(OH)(2)D(3) than did those from normal controls. These PBMCs released less NO than did those from control subjects, at baseline and in the stimulated state. We found that 1,25(OH)(2)D(3) dose-dependently inhibited iNOS messenger RNA expression of the LPS-stimulated RAW 264.7 cells and also significantly reduced the gaseous NO release and OONO(-) production. Paralleling the 1,25(OH)(2)D(3)-induced inhibition of NO release were reductions in OONO(-) and LDH production. In conclusion, 1,25(OH)(2)D(3) inhibited iNOS expression and reduced NO production by LPS-stimulated macrophages in the range of physiological doses. Inhibition of the NO surge was coupled with a reduction in OONO(-) and LDH production. Increased 1,25(OH)(2)D(3) production and decreased release of NO from the PBMCs of patients with tuberculosis and hypercalcemia were also noted. We propose that 1,25(OH)(2)D(3) production by macrophages may protect themselves against oxidative injuries caused by the NO burst. In the case of tuberculosis infection, increased 1,25(OH)(2)D(3) synthesis may further contribute to the development of an unwanted phenomenon-hypercalcemia.
在肉芽肿性感染中，诱导型一氧化氮合酶（iNOS）的表达以及巨噬细胞释放一氧化氮（NO）均显著增加。巨噬细胞1α-羟化酶的激活会导致1α,25-二羟基维生素D(3) [1,25(OH)(2)D(3)]增加。然而，这种产量增加的意义尚未完全明确。在本研究中，我们分析了结核病感染伴高钙血症患者体内1,25(OH)(2)D(3)和NO的产生情况，并使用脂多糖（LPS）刺激RAW 264.7细胞，以评估1,25(OH)(2)D(3)对iNOS表达和气态NO产生的调节作用。同时还检测了过氧亚硝酸盐（OONO(-)）的产生和乳酸脱氢酶活性。在无额外刺激的情况下，结核病患者的外周血单核细胞（PBMC）将25-羟基维生素D(3)转化为1,25(OH)(2)D(3)的能力比正常对照者更强。在基线和刺激状态下，这些PBMC释放的NO均少于对照受试者。我们发现，1,25(OH)(2)D(3)能剂量依赖性地抑制LPS刺激的RAW 264.7细胞中iNOS信使核糖核酸的表达，还能显著降低气态NO的释放以及OONO(-)的产生。与1,25(OH)(2)D(3)诱导的NO释放抑制同时出现的是OONO(-)和LDH产生的减少。总之，在生理剂量范围内，1,25(OH)(2)D(3)可抑制LPS刺激的巨噬细胞中iNOS的表达并减少NO的产生。对NO激增的抑制与OONO(-)和LDH产生的减少相关。我们还注意到，结核病伴高钙血症患者的PBMC中1,25(OH)(2)D(3)产量增加且NO释放减少。我们推测，巨噬细胞产生1,25(OH)(2)D(3)可能保护自身免受NO爆发引起的氧化损伤。在结核病感染的情况下，1,25(OH)(2)D(3)合成增加可能会进一步导致一种不良现象——高钙血症的发生发展。
