Aldose Reductase: A Regulator of Inflammatory Signals

描述（由申请人提供）：我们最近的研究表明醛糖还原酶（AR）在脂质过氧化生成的脂质衍生醛（lda）及其与谷胱甘肽结合物的解毒中起着关键作用。4-羟基反式-2-壬烯醛（HNE）是脂质过氧化过程中产生的最具毒性和最丰富的LDA之一，而GS-HNE被AR有效地还原。我们进一步证明AR介导tnf - α、生长因子和高血糖产生的活性氧（ROS）的有丝分裂和细胞毒性信号，分别导致血管平滑肌细胞和血管内皮细胞的增殖和凋亡。我们还观察到，特异性抑制剂对AR的抑制或反义或RNAi对AR的消融会减弱PKC和MAPK的激活、ikappab - α的磷酸化和降解以及NF-kappaB和API的激活。此外，AR抑制可减弱脂多糖（LPS）诱导的小鼠腹腔巨噬细胞中细胞因子如tnf - α、IL-6和IL-10、次级信使cAMP和前列腺素E2的分泌。我们的假设是AR在通过ROS介导的lps诱导的炎症反应的转导中起关键作用。现在，我们将通过研究小鼠腹膜巨噬细胞和RAW246.7细胞释放lps诱导的细胞因子和趋化因子来系统地验证我们的假设，并确定AR消融抑制这些细胞毒性信号的机制。通过AR抑制lps诱导的炎症细胞因子和趋化因子在肝脏、脾脏、小肠、肾脏、心脏和血清中的衰减，并与小鼠组织炎症的衰减相关。因此，我们的目标是：1)阐明AR在细菌内毒素（LPS）诱导的巨噬细胞细胞毒性信号中的作用；2)研究AR在LPS诱导的小鼠巨噬细胞促炎细胞因子和趋化因子表达中的作用；3)确定AR的分子机制和可能的靶点；4)研究AR在小鼠体内调节细胞因子和趋化因子的产生和炎症中的作用。这些研究的完成将证明AR抑制剂如何减弱ros介导的LPS和细胞因子信号，为预防炎症诱导的毒性提供一种新的治疗方法，并阐明AR参与这些并发症的分子机制。

DESCRIPTION (provided by applicant): Our recent studies have demonstrated that aldose reductase (AR), plays a pivotal rote in the detoxification of lipid peroxidation-generated lipid derived aldehydes (LDAs) and their conjugates with GSH. 4-hydroxy trans-2-nonenal (HNE), one of the most toxic and abundant LDA generated during lipid peroxidation and GS-HNE are efficiently reduced by AR. We have further demonstrated that AR mediates the mitogenic and cytotoxic signals of reactive oxygen species (ROS) generated by TNF-alpha, growth factors and hyperglycemia leading to proliferation and apoptosis of vascular smooth muscle cells and vascular endothelial cells, respectively. We have also observed that inhibition of AR by specific inhibitors or ablation of AR by antisense or RNAi attenuates the activation of PKC and MAPK, phosphorylation and degradation of IkappaB-alpha and activation of NF-kappaB and API. Also, AR inhibition attenuates lipopolysaccharide (LPS)-induced secretion of cytokines such as TNF-alpha, IL-6, and IL-10, secondary messenger cAMP and prostaglandin E2 in mouse peritoneal macrophages. Our hypothesis is that AR plays a pivotal role in the transduction of LPS-induced inflammatory responses mediated via ROS. We will now systematically examine our hypothesis by investigating the release of LPS-induced cytokines and chemokines by mouse peritoneal macrophages and RAW246.7 cells and identify the mechanism(s) of inhibition of these cytotoxic signals by AR ablation. Attenuation of LPS-induced inflammatory cytokines and chemokines by AR inhibition will be investigated in the liver, spleen, small intestine, kidney, heart and serum, and correlated with attenuation of inflammation in tissues of mice. Thus our aims are to 1) Delineate the involvement of AR in bacterial endotoxin (LPS)-induced cytotoxic signals in macrophages, 2) Investigate the role of AR in LPS-induced expression of proinflammatory cytokines and chemokines in mouse macrophages, 3) Identify the molecular mechanisms and possible targets of AR and 4) Investigate the in vivo role of AR in the regulation of cytokine and chemokine generation and inflammation in mice. Completion of these studies will demonstrate how AR inhibitors attenuate the ROS-mediated LPS and cytokine signals, provide a novel therapeutic approach for preventing inflammation-induced toxicity and elucidate the molecular mechanism(s) of AR's involvement in these complications.