在Thy 1肾小球肾炎中，诱导型一氧化氮合酶的诱导是补体和活性氧依赖性的。

Inducible nitric oxide synthase induction in Thy 1 glomerulonephritis is complement and reactive oxygen species dependent.

作者信息

Mosley K, Waddington S N, Ebrahim H, Cook T, Cattell V

机构信息

Department of Experimental Pathology, Imperial College School of Medicine, St. Mary's Campus, London, UK.

出版信息

Exp Nephrol. 1999 Jan-Feb;7(1):26-34. doi: 10.1159/000020581.

DOI:10.1159/000020581

PMID:9892811

Abstract

Thy 1 glomerulonephritis (GN) is a rat model of complement-dependent immune mesangial injury with induced glomerular nitric oxide (NO) synthesis. To examine mechanisms of inducible nitric oxide synthase (iNOS) induction, we studied the effects of treatment with the antioxidant N-acetyl-cysteine (NAC) and soluble complement receptor 1 (sCR1). Thy 1 GN was induced by intravenous anti-Thy 1 antibody. Glomeruli were isolated and kidney tissue taken from 30 min to 24 h after induction. Nitrite (NO-2) synthesis, luminol chemiluminescence for reactive oxygen species (ROS), and iNOS and cytokine mRNA were assayed in isolated glomeruli. Mesangial injury (mesangiolysis) and leucocyte infiltration were quantitated on tissue sections. NAC (i.p. 1,000 mg/kg, 1 h prior to anti-Thy 1) reduced glomerular NO-2 synthesis (3.5 +/- 0.66 vs. untreated 8.2 +/- 1.1, p = 0.02), and iNOS mRNA expression, and abolished enhanced chemiluminescence. In vitro incubation of nephritic glomeruli with 20 mM NAC also suppressed nitrite production (4.7 +/- 0.8 vs. untreated 12.2 +/- 0. 7 nmol NO-2/2,000 glomeruli/48 h, p = 0.003), and chemiluminescence. In NAC-treated animals, neutrophil infiltration (0.5 +/- 0 vs. untreated 9.6 +/- 1.6 glomerulus, p = 0.0005), and macrophage infiltration (1.7 +/- 0.4 vs. untreated 12.0 +/- 0.1, p = 0.006) were abolished, and mesangiolysis was significantly reduced (45.9 +/- 1.3 vs. untreated 34.4 +/- 2.1 cells/glomerulus, p = 0.009). NAC did not inhibit anti-Thy 1 antibody deposition. C1q was unaffected, but C3 was reduced. sCR1 treatment prevented iNOS mRNA induction, the enhanced chemiluminescence, and the neutrophil infiltration at 1 h. IL-1beta and TNFalpha mRNAs were not affected by either NAC or sCR1. These results show that NAC inhibits iNOS induction and NO synthesis in this model, and suppresses ROS synthesis and injury. They suggest that complement-dependent ROS generation is the critical initiating event that follows fixation of anti-Thy 1 antibody.

摘要

Thy1肾小球肾炎（GN）是一种依赖补体的免疫性系膜损伤大鼠模型，伴有诱导性肾小球一氧化氮（NO）合成。为研究诱导型一氧化氮合酶（iNOS）诱导的机制，我们研究了抗氧化剂N-乙酰半胱氨酸（NAC）和可溶性补体受体1（sCR1）治疗的效果。通过静脉注射抗Thy1抗体诱导Thy1 GN。诱导后30分钟至24小时分离肾小球并取肾组织。检测分离肾小球中的亚硝酸盐（NO₂）合成、用于活性氧（ROS）的鲁米诺化学发光以及iNOS和细胞因子mRNA。对组织切片上的系膜损伤（系膜溶解）和白细胞浸润进行定量。NAC（腹腔注射1000mg/kg，在抗Thy1前1小时）减少了肾小球NO₂合成（3.5±0.66对未治疗的8.2±1.1，p = 0.02）、iNOS mRNA表达，并消除了增强的化学发光。用20mM NAC对肾炎性肾小球进行体外孵育也抑制了亚硝酸盐产生（4.7±0.8对未治疗的12.2±0.7nmol NO₂/2000个肾小球/48小时，p = 0.003）和化学发光。在NAC治疗的动物中，中性粒细胞浸润（0.5±0对未治疗的9.6±1.6个肾小球，p = 0.0005）和巨噬细胞浸润（1.7±0.4对未治疗的12.0±0.1，p = 0.006）被消除，系膜溶解显著减少（45.9±1.3对未治疗的34.4±2.1个细胞/肾小球，p = 0.009）。NAC不抑制抗Thy1抗体沉积。C1q未受影响，但C3减少。sCR1治疗在1小时时阻止了iNOS mRNA诱导、增强的化学发光和中性粒细胞浸润。IL-1β和TNFα mRNA不受NAC或sCR1影响。这些结果表明，在该模型中NAC抑制iNOS诱导和NO合成，并抑制ROS合成和损伤。它们提示补体依赖性ROS生成是抗Thy1抗体固定后关键的起始事件。