Chronic inhibition of NOS-2 ameliorates renal injury, as well as COX-2 and TGF-β1 overexpression in 5/6 nephrectomized rats
Chronic inhibition of NOS-2 ameliorates renal injury, as well as COX-2 and TGF-β1 overexpression in 5/6 nephrectomized rats
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DOI：
10.1093/ndt/gfl444
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发表时间：
2006-11-01
影响因子：
6.1
通讯作者：
Herrera-Acosta, Jaime
中科院分区：
文献类型：
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作者：
Bautista-Garcia, Pablo;Sanchez-Lozada, Laura Gabriela;Herrera-Acosta, Jaime
背景慢性肾损害与炎症浸润、纤维化和血管病变有关，并伴有环氧合酶2（考克斯-2）和转化生长因子β 1（TGF-β 1）表达增加。然而，诱导型一氧化氮合酶（NOS-2）的作用仍有争议。因此，我们研究了NOS-2对考克斯-2和TGF-β 1表达水平的影响，以及肾次全消融（5/6 Nx）大鼠肾结构损伤的作用。研究了四组大鼠：假手术组、5/6 Nx组、5/6 Nx +氨基胍（AG）组和5/6 NX + L-NIL（L-N6-亚氨基乙基-赖氨酸）组。测定收缩压（SBP）、尿蛋白、肌酐（Cr）清除率。实时荧光定量逆转录聚合酶链反应检测NOS-2、考克斯-2和TGF-β 1基因表达。通过蛋白质印迹和ELISA（TGF-β 1）评估蛋白质表达。免疫组化和形态计量学检测NOS-2、微血管增厚和纤维化。5/6只Nx大鼠出现高血压、蛋白尿、NOS-2、考克斯-2和TGF-β 1表达增加、小动脉壁增厚、肾小管间质纤维化。慢性抑制NOS-2不能防止动脉高血压或Cr清除率下降，但部分减少蛋白尿。然而，AG和L-NIL保留了小动脉形态，并且两种诱导型NOS的选择性抑制剂（AG和L-NIL）的施用防止了NOS-2的过度表达。结果表明，5/6只Nx大鼠肾组织NOS-2表达明显增强。此外，AG和L-NIL治疗预防了肾次全消融引起的形态功能变化，尽管持续存在全身性高血压，这表明NOS-2产生的高浓度一氧化氮可作为参与肾脏疾病进展的促炎和促纤维化途径的正调节剂。
Background. Chronic renal damage is associated with inflammatory infiltration, fibrosis and vascular lesion, coupled with increased expression of cyclo-oxygenase 2 (COX-2) and transforming growth factor-beta 1 (TGF-beta 1). However, the role of inducible nitric oxide synthase (NOS-2) is still controversial. Thus, we studied the contribution of NOS-2 to the expression levels of COX-2 and TGF-beta 1, as well as the structural renal injury in rats with subtotal renal ablation (5/6 Nx).Methods. Four groups of rats were studied: sham, 5/6 Nx, 5/6 Nx + aminoguanidine (AG) and 5/6 NX + L-NIL (L-N6-iminoethyl-lysine). Systolic blood pressure (SBP), proteinuria and creatinine (Cr) clearance were measured. NOS-2, COX-2 and TGF-beta 1 gene expression was determined by real-time reverse transcription-polymerase-chain reaction. Protein expression was evaluated by western blot and ELISA (TGF-beta 1). Immunohistochemistry and morphometry were performed for NOS-2, microvascular thickening and fibrosis.Results. Systemic hypertension and marked proteinuria, increased expression of NOS-2, COX-2 and TGF-beta 1, thickening of arteriolar wall and tubulointerstitial fibrosis were produced in 5/6 Nx rats. Chronic inhibition of NOS-2 did not prevent arterial hypertension or the fall in Cr clearance, but partially reduced proteinuria. Nevertheless, AG and L-NIL preserved arteriolar morphology and the administration of both selective inhibitors of inducible NOS (AG and L-NIL) prevented NOS-2 overexpression.Conclusion. This study shows that NOS-2 was markedly enhanced in renal tissue of 5/6 Nx rats. Moreover, treatment with AG and L-NIL prevented the morpho-functional changes induced by subtotal renal ablation, despite persistence of systemic hypertension, suggesting that high concentrations of nitric oxide produced by NOS-2 could act as a positive modulator of the proinflammatory and profibrotic pathways involved in the progression of renal disease.