Ramana Kota V, Fadl Amin A, Tammali Ravinder, Reddy Aramati B M, Chopra Ashok K, Srivastava Satish K
Department of Biochemistry, University of Texas Medical Branch, Galveston, Texas 77555, USA.
J Biol Chem. 2006 Nov 3;281(44):33019-29. doi: 10.1074/jbc.M603819200. Epub 2006 Sep 6.
Abnormal production of inflammatory cytokines and chemokines is a key feature of bacterial endotoxin, lipopolysaccharide (LPS)-induced inflammation, and cytotoxicity; however, the mechanisms regulating production of inflammatory markers remain unclear. Herein, we show that inhibition of the aldehyde-metabolizing enzyme aldose reductase (AR; AKR1B3) modulates NF-kappaB-dependent activation of inflammatory cytokines and chemokines in mouse serum, liver, heart, and spleen. Pharmacological inhibition or small interfering RNA ablation of AR prevented the biosynthesis of tumor necrosis factor-alpha, interleukin 1beta, interleukin-6, macrophage-chemoattractant protein-1, and cyclooxygenase-2 and prostaglandin E(2) in LPS-activated RAW264.7 murine macrophages. The AR inhibition or ablation significantly attenuated LPS-induced activation of protein kinase C (PKC) and phospholipase C (PLC), nuclear translocation of NF-kappaB, and phosphorylation and proteolytic degradation of IkappaBalpha in macrophages. Furthermore, treatment of macrophages with 4-hydroxy-trans-2-nonenal (HNE), and cell-permeable esters of glutathionyl-4-hydroxynonanal (GS-HNE) and glutathionyl-1,4-dihydroxynonane (GS-DHN) activated NF-kappaB and PLC/PKC. Pharmacological inhibition or antisense ablation of AR that catalyzes the reduction of GS-HNE to GS-DHN prevented PLC, PKC, IKKalpha/beta, and NF-kappaB activation caused by HNE and GS-HNE, but not by GS-DHN, suggesting that reduced GS-lipid aldehydes catalyzed by AR propagate LPS-induced production of inflammatory markers. Collectively, these data provide evidence that inhibition of AR may be a significant therapeutic approach in preventing bacterial endotoxin-induced sepsis and tissue damage.
炎性细胞因子和趋化因子的异常产生是细菌内毒素、脂多糖（LPS）诱导的炎症和细胞毒性的关键特征；然而，调节炎性标志物产生的机制仍不清楚。在此，我们表明抑制醛代谢酶醛糖还原酶（AR；AKR1B3）可调节小鼠血清、肝脏、心脏和脾脏中炎性细胞因子和趋化因子的NF-κB依赖性激活。AR的药理学抑制或小干扰RNA敲除可防止LPS激活的RAW264.7小鼠巨噬细胞中肿瘤坏死因子-α、白细胞介素1β、白细胞介素-6、巨噬细胞趋化蛋白-1以及环氧化酶-2和前列腺素E2的生物合成。AR抑制或敲除显著减弱了LPS诱导的巨噬细胞中蛋白激酶C（PKC）和磷脂酶C（PLC）的激活、NF-κB的核转位以及IκBα的磷酸化和蛋白水解降解。此外，用4-羟基反式-2-壬烯醛（HNE）以及谷胱甘肽基-4-羟基壬醛（GS-HNE）和谷胱甘肽基-1,4-二羟基壬烷（GS-DHN）的细胞可渗透酯处理巨噬细胞可激活NF-κB和PLC/PKC。催化GS-HNE还原为GS-DHN的AR的药理学抑制或反义敲除可防止由HNE和GS-HNE引起的PLC、PKC、IKKα/β和NF-κB激活，但不能防止由GS-DHN引起的激活，这表明AR催化的GS-脂质醛还原可促进LPS诱导的炎性标志物产生。总体而言，这些数据提供了证据，表明抑制AR可能是预防细菌内毒素诱导的败血症和组织损伤的重要治疗方法。
