环氧化酶-2与肺损伤

肺损伤是指各种致病因素(物理、化学和生物性因素)作用于肺脏组织而引起的肺组织细胞的变性、坏死及肺功能的改变,多种炎性介质及细胞因子参与了肺损伤的过程.环氧化酶-2(COx-2)为一种诱导酶,当细胞受到炎症等刺激时可高表达,是炎症介导的细胞毒性重要的决定因素之一.在各种原因所导致的肺损伤中,COX-2表达增多的现象提示COX-2在肺损伤发生发展中具有重要作用,COX-2作为肺损伤的治疗靶点将成为今后研究的热点.     

PAF对BV2细胞炎症因子分泌的影响及转录组学分析

探究血小板活化因子（Platelet activating factor,PAF）对BV2细胞炎症因子分泌的影响及初步推测其调控机制。外源PAF(2×10^-5M)作用于BV2细胞24 h,36 h,48 h后,（1）CCK8实验检测空白对照组,Mock组和PAF处理组细胞活性;（2）ELISA实验测炎症因子TNFα、IL-6、Cxcl2、IL-1a的分泌;（3）Western Blot检测炎症介质COX-2蛋白水平;（4）对PAF处理24h的BV2细胞以及对应的Mock组细胞进行RNA测序得到转录组测序结果;（5）GO和KEGG富集分析后,运用String数据库配合Cytoscape软件找出炎症相关的Hub基因并挑选出以下基因（Ccl4、Ccl3、Ccl7、IL-1a、Cxcl2、IL1f9、IL34、COX-2、Serpinb1a）进行qPCR验证。实验结果表明,PAF作用时间为24 h,36 h,48 h后,相比对照组：（1）BV2细胞活性降低;（2）上清液中的炎症因子TNFα,IL-6,IL-1a,Cxcl2分泌增加;（3）炎症介质COX-2蛋白表达水平上调...     

COX-2在炎症消退中的研究进展

环氧化酶-2(cyclooxygenase-2,COX-2)为一种在正常组织中较少表达的诱导酶,而当细胞受到炎症刺激时大量表达。由于COX-2可以快速应答一系列促炎介质和细胞因子,因此长久以来一直被认为在炎症发生的病理过程中扮演重要角色。然而COX-2通过产生不同的前列腺素不仅具有促炎作用,还可发挥抗炎促消退功能,如通过产生15ΔPGJ2与NF-κB、STAT3、AP-1等促炎转录因子相互作用发挥拮抗炎症和氧化应激的保护功能。考虑到减少COX-2表达导致的负面影响的同时也损害了它的积极作用,我们认为抑制COX-2表达以抑制炎症的这种治疗方案有待商榷。本文概述了COX-2/前列腺素在炎症中的积极作用,并期望通过进一步理解COX-2的双重作用,来探索发展炎症疾病的新型治疗方案。     

COX-2与VEGF-C在大肠癌中的表达及与预后的关系

目的探讨COX-2与VEGF-C在大肠癌组织中的表达及与临床病理因素之间的关系。方法运用免疫组化方法检测54例大肠癌组织中COX-2与VEGF-C的表达。结果COX-2和VEGF-C蛋白在大肠癌中的表达阳性率分别为72．22％（39／54）和64．81％（35／54）,COX-2与VEGF-C表达之间存在显著的相关性（P〈0．001）;在伴有淋巴结转移的大肠腺癌中,COX-2与VEGF-C的阳性表达率分别为87．5g（21／24）和91．67％（22／24）,转移组与非转移组相比较均有显著性差异（P＜0．05）;COX-2蛋白表达与肿瘤大小、浸润深度、Duke’s分期呈负相关（P〈0．05）,与组织分化、性别、年龄等临床病理因素无关（P〉0.05）。VEGF-C表达与浸润深度、Duke’s分期呈负相关（P〈0．05）,与组织分化、性别、年龄、肿瘤大小等临床病理因素无关（P〉0．05）。结论COX-2蛋白与VEGF-C共表达可增加大肠癌转移和侵袭能力,其检测有助于大肠癌恶性程度评价及临床预后的判断。     

Cox-2和Suvrivin蛋白在眼睑基底细胞癌组织中的表达

目的探讨Cox-2和Suvrivin蛋白在眼睑基底细胞癌组织中的表达及临床意义。方法收集武汉大学人民医院和武汉大学中南医院病理科1999-2006年手术切除及活检的眼睑基底细胞癌（basal cell carcinoma,BCC）标本共40例,另取癌周围组织5例作对照。眼睑基底细胞癌发病年龄20-68岁。采用免疫组织化学方法观察各组细胞内Cox-2和Suvrivin蛋白表达的变化。利用HPIAS-2000图像分析系统测定Cox-2和Suvrivin蛋白在以上各组中表达的平均光密度和平均阳性面积率。结果眼睑基底细胞癌组织中COX-2蛋白呈高表达;癌旁组织中COX-2蛋白呈低表达。眼睑基底细胞癌组织中Suvrivin蛋白呈高表达;癌旁组织中Suvrivin蛋白呈低表达。图像分析结果显示：眼睑基底细胞癌组织与癌旁组织之间COX-2和Suvrivin蛋白的平均光密度及阳性面积率的差异有显著性意义（P〈0.01）。结论COX-2、Survivin在眼睑BCC中的异常表达,对眼睑BCC的发生和发展起了重要作用。     

CDC对胰岛13细胞中COX-2表达及PGE2生成的影响

目的观察12／15脂氧合酶抑制剂CDC对大鼠胰岛B细胞中环加氧酶2（COX-2）的表达及前列腺素E2（PGE2）生成的影响,并初步探讨其机制。方法体外培养大鼠胰岛β细胞系INS-1细胞,加入细胞因子IL-1β诱导COX-2蛋白的表达,然后采用Western印迹的方法观察12／15脂氧合酶抑制剂cin-naminyl-3,4-dihydroxy-α-cyanocinnamate（CDC）对COX-2蛋白表达的影响;借助萤光素酶报告基因技术检测CDC对COX-2启动子转录活性的影响,最后用放射免疫法了解CDC对胰岛B细胞中PGE2生成的抑制作用。结果细胞因子IL-1p能够在大鼠胰岛β细胞系INS-1中诱导COX-2基因的表达,而12／15脂氧合酶抑制剂CDC能够呈剂量依赖抑制IL-1p所诱导的COX-2蛋白的表达。结论12／15脂氧合酶抑制剂能够明显抑制炎性因子IL-1β所诱导的胰岛β细胞中COX-2的表达和炎性介质PGE2的生成。     

COX-2抑制剂在胃癌中的研究进展

环氧合酶-2(COX-2)是催化花生四烯酸合成前列腺素的关键限速酶,呈诱导性表达在病变组织中,参与各种损伤性化学、肿瘤、炎症、发热、凝血、疼痛等病理过程。近年来大量研究表明,COX-2在胃癌的发生发展及转移中起着关键性作用,COX-2在肿瘤增殖、血管生成、侵袭转移及抑制细胞凋亡中的作用已经受到医学界的关注,诸多研究表明选择性COX-2抑制剂不仅能够抑制胃癌细胞的增殖和促进癌细胞凋亡,还能降低胃癌细胞的侵袭转移能力,有助于胃癌的防治。随着COX-2与胃癌关系研究的深入,作为胃癌防治靶点之一的COX-2,已经成为胃癌治疗的热点。本文主要讨论COX-2及其抑制剂在胃癌的中作用及研究进展。     

鼻咽癌组织COX-2、SDHB、HSP90β表达与临床病理特征及预后的关系研究

摘要 目的：探讨鼻咽癌组织环氧化酶-2（COX-2）、琥珀酸脱氢酶（SDHB）、热休克蛋白90β（HSP90β）表达与临床病理特征及预后的关系。方法：应用免疫组织化学染色法对78例鼻咽癌组织和65例鼻咽部慢性炎症组织中COX-2、SDHB、HSP90β表达情况进行检测,并分析鼻咽癌组织中COX-2、SDHB、HSP90β表达与临床病理特征的关系及其相关性。所有患者随访3年,根据不同COX-2、SDHB、HSP90β表达情况将患者分为COX-2阳性组、COX-2阴性组、SDHB阳性组、SDHB阴性组、HSP90β阳性组、HSP90β阴性组,比较各组患者生存情况。结果：鼻咽癌组织中COX-2、HSP90β阳性率显著高于鼻咽部慢性炎症组织,SDHB阳性率显著低于鼻咽部慢性炎症组织（P<0.05）。TNM分期为III+IV期、中低分化、有颈淋巴结转移者鼻咽癌组织中COX-2、HSP90β阳性率显著高于TNM分期为I+II期、高分化、无颈淋巴结转移者,SDHB阳性率显著低于TNM分期为I+II期、高分化、无颈淋巴结转移者（P<0.05）。Spearman相关分析显示,鼻咽癌组织中COX-2表达与SDHB表达呈负相关（rs=-0.462, P=0.008）,与HSP90β表达呈正相关（rs=0.501, P=0.000）,HSP90?茁表达与SDHB表达呈负相关（rs=-0.438, P=0.012）。随访3年,存活49例,死亡29例,存活率62.82%。鼻咽癌组织COX-2阴性组、SDHB阳性组、HSP90β阴性组患者生存率、中位生存期显著优于COX-2阳性组、SDHB阴性组、HSP90β阳性组患者（P<0.05）。结论：鼻咽癌组织中COX-2、SDHB、HSP90β表达情况与患者TNM分期、肿瘤分化情况和颈淋巴结转移相关,且其表达情况与鼻咽癌患者生存期有密切关系。     

草木犀石油醚提取物对小鼠巨噬细胞促炎介质的影响

目的研究草木犀石油醚提取物在体外的抗炎作用。方法采用小鼠巨噬细胞系RAW264．7建立炎症细胞模型,加入10μg/L的LPS培养液和不同浓度的草木犀石油醚提取物进行干预。ELISA法检测上清液中TNF-α,IL-1β,IL-6和NO的分泌量;实时荧光定量RT-PCR检测TNF-α,iNOS和COX-2的mRNA表达;Western印迹法检测COX-2蛋白的表达。结果草木犀提取物干预后细胞所分泌的炎性介质（TNF—α,IL-1β,IL-6和NO）与模型组相比均显著降低（P〈0．01）,并存在剂量依赖关系;RT-PCR结果显示干预后细胞TNF-α,iNOS和COX-2的mRNA表达水平显著降低（P〈0．01）,也存在剂量依赖关系;Western印迹结果显示草木犀石油醚提取物及地塞米松干预后COX-2蛋白水平明显降低（P〈0．01）。结论草木犀的石油醚提取物通过下调LPS诱导的巨噬细胞表达炎性介质而发挥其体外抗炎作用,且其下调作用呈剂量依赖性。     

甲基苯丙胺中毒大鼠纹状体COX-2、PGE2、EP2受体及小胶质细胞表达的研究

目的：通过研究COX-2、PGE2、EP2受体及小胶质细胞在甲基苯丙胺中毒大鼠纹状体内的表达变化探讨甲基苯丙胺中毒大鼠纹状体中COX-2／PGE2系统与小胶质细胞活化之间的关系。方法：将40只健康成年雄性SD大鼠,随机分成对照组10只和实验组30只（实验组分成三个亚组,分为末次给药后1天组、2天组和3天组,n=10）。实验组给予10mg／kg的MA腹腔注射,对照组给予同样剂量的生理盐水,每天注射两次,注射时间为8：00、20：00,连续注射4天。分别于末次给药后的第1天、第2天、第3天处杀。用免疫组化技术对中毒大鼠纹状体（CPU）中COX-2、EP2受体及Iba1（钙离子接头蛋白,小胶质细胞内一种特异性标记物）的表达进行检测,并进行图像分析。另外,取大鼠的纹状体运用酶联免疫法检测PGE2的含量。结果：COX-2、PGE2、EP2受体及小胶质细胞在各组均有表达。与对照组相比,实验组中：COX-2、PGE2、EP2受体的1天组表达均不同程度下降;2天组中COX-2表达水平大幅度上升,PGE2、EP2受体表达仍低于正常水平;3天组COX-2表达水平继续升高,而PGE2、EP2受体表达趋于正常组水平。而小胶质细胞表达水平则是三个实验组均高于正常组,且3天组高于2天组,2天组高于l天组。对照组与实验组有显著性差异（P〈0．05）。结论：COX-2／PGE2系统与甲基苯丙胺中毒大鼠纹状体内小胶质细胞活化无明显相关性;COX-2与甲基苯丙胺的神经毒性有关。     

Inhibition of cyclooxygenase-2 ameliorates the severity of pancreatitis and associated lung injury

Cyclooxygenase-2 (COX-2), a widely distributed enzyme, plays an important role in inflammation. We have studied the role of COX-2 in acute pancreatitis and pancreatitis-associated lung injury using both the pharmacological inhibition of COX-2 and genetic deletion of COX-2. Pancreatitis was induced in mice by 12 hourly injections of cerulein. The severity of pancreatitis was assessed by measuring serum amylase, pancreatic trypsin activity, intrapancreatic sequestration of neutrophils, and acinar cell necrosis. The severity of lung injury was evaluated by measuring lactate dehydrogenase levels in the bronchoalveolar lavage fluid and by quantitating neutrophil sequestration in the lung. In both the pharmacologically inhibited and genetically altered mice, the severity of pancreatitis and pancreatitis-associated lung injury was reduced compared with the noninhibited strains of COX-2-sufficient mice. This reduction in injury indicates that COX-2 plays an important proinflammatory role in pancreatitis and its associated lung injury. Our findings support the concept that COX-2 inhibitors may play a beneficial role in the prevention of acute pancreatitis or in the reduction of its severity.     

COX-1 and COX-2 polymorphisms in susceptibility to cerebral palsy in very preterm infants

Cerebral palsy (CP) is a nonprogressive motor disorder caused by white matter damage in the developing brain. Recent epidemiological and clinical data suggest intrauterine infection/inflammation as the most common cause of preterm delivery and neonatal complications, including CP. Cyclooxygenases are key enzymes in the conversion of arachidonic acid to prostaglandins. The COX family consists of two isoforms, COX-1 and COX-2. In the brain, COX-2 is constitutively expressed at high levels on pyramidal neurons, while COX-1 is predominantly expressed by microglia and can be upregulated in pathological conditions, such as infection, ischemia and traumatic brain injury. Single nucleotide polymorphisms in the COX-1 and COX-2 gene could have profound effects on COX-1 and COX-2 expression and, directly or indirectly, influence the pathogenesis, development and severity of CP. In this study we investigated the association between single nucleotide polymorphisms of the COX-1 and COX-2 gene and susceptibility to cerebral palsy in very preterm infants. The results of our study showed the association between COX-1 high expression genotype (?842 AA) and COX-1 high expression allele ?842A and risk of CP in infants with cystic periventricular leucomalacia (cPVL). Our results support an important role of COX-1 enzyme on microglial activation during neuroinflammation resulting in huge neuroinflammatory response and the proinflammatory mediator overproduction, with the serious white matter damage and CP development as a consequence.     

Regulation of COX-2 expression by miR-146a in lung cancer cells

Prostaglandins are a class of molecules that mediate cellular inflammatory responses and control cell growth. The oxidative conversion of arachidonic acid to prostaglandin H₂ is carried out by two isozymes of cyclooxygenase, COX-1 and COX-2. COX-1 is constitutively expressed, while COX-2 can be transiently induced by external stimuli, such as pro-inflammatory cytokines. Interestingly, COX-2 is overexpressed in numerous cancers, including lung cancer. MicroRNAs (miRNAs) are small RNA molecules that function to regulate gene expression. Previous studies have implicated an important role for miRNAs in human cancer. We demonstrate here that miR-146a expression levels are significantly lower in lung cancer cells as compared with normal lung cells. Conversely, lung cancer cells have higher levels of COX-2 protein and mRNA expression. Introduction of miR-146a can specifically ablate COX-2 protein and the biological activity of COX-2 as measured by prostaglandin production. The regulation of COX-2 by miR-146a is mediated through a single miRNA-binding site present in the 3′ UTR. Therefore, we propose that decreased miR-146a expression contributes to the up-regulation and overexpression of COX-2 in lung cancer cells. Since potential miRNA-mediated regulation is a functional consequence of alternative polyadenylation site choice, understanding the molecular mechanisms that regulate COX-2 mRNA alternative polyadenylation and miRNA targeting will give us key insights into how COX-2 expression is involved in the development of a metastatic condition.     

Non-small cell lung cancer cyclooxygenase-2-dependent invasion is mediated by CD44

Elevated tumor cyclooxygenase (COX-2) expression is associated with increased angiogenesis, tumor invasion, and suppression of host immunity. We have previously shown that genetic inhibition of tumor COX-2 expression reverses the immunosuppression induced by non-small cell lung cancer (NSCLC). To assess the impact of COX-2 expression in lung cancer invasiveness, NSCLC cell lines were transduced with a retroviral vector expressing the human COX-2 cDNA in the sense (COX-2-S) and antisense (COX-2-AS) orientations. COX-2-S clones expressed significantly more COX-2 protein, produced 10-fold more prostaglandin E(2), and demonstrated an enhanced invasive capacity compared with control vector-transduced or parental cells. CD44, the cell surface receptor for hyaluronate, was overexpressed in COX-2-S cells, and specific blockade of CD44 significantly decreased tumor cell invasion. In contrast, COX-2-AS clones had a very limited capacity for invasion and showed diminished expression of CD44. These findings suggest that a COX-2-mediated, CD44-dependent pathway is operative in NSCLC invasion. Because tumor COX-2 expression appears to have a multifaceted role in conferring the malignant phenotype, COX-2 may be an important target for gene or pharmacologic therapy in NSCLC.     

Role of nitric oxide in the regulation of fibrogenic factors in experimental liver fibrosis in mice

Previously, we have shown that an increased expression level of iNOS but a reduction in the expression of eNOS is associated with increased oxidative stress markers in CCl?-induced experimental liver fibrosis. The present study aimed to investigate the effect of L-arginine and 5-methylisothiourea hemisulfate (SMT) in the expression of profibrogenic factors in chronic liver injury. ICR mice were treated with CCl? with or without treatment of L-arginine, an NO donor, or SMT, an iNOS inhibitor. The expression of matrix metalloptroteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), α-smooth muscle actin (α-SMA), tumor necrosis factor-α (TNF-α) and cyclooxygenase-2 (COX-2) were investigated by RT-PCR. The activity of the MMP-2 and MMP-9 were measured by zymography. Our results showed that CCl?-treated mice showed significant up-regulation of expression of pro-fibrogenic factors, TNF-α and COX-2. Treatment with L-arginine or SMT showed a significant reduction in CCl?-induced expression of these pro-fibrogenic factors, TNF-α and COX-2. In conclusion, both SMT and L-arginine effectively attenuated the progression of CCl?-induced liver fibrosis. SMT suppresses iNOS mediated NO production. However, L-arginine augments NO production. The similar effect of the two drugs on liver fibrosis indicates that there may be two distinct pathways of NOS mediated fibrogenesis in chronic liver injury by iNOS and eNOS. Our results suggest that eNOS-mediated liver fibrogenesis may play a more important role than that of iNOS in chronic liver injury. Taken together, these results support the contention that NO plays an active role in the progression of liver fibrosis and hepatocellular damage.     

Cyclooxygenase 2 plays a pivotal role in the resolution of acute lung injury

Acute lung injury (ALI) is a severe illness with excess mortality and no specific therapy. In its early exudative phase, neutrophil activation and accumulation in the lung lead to hypoxemia, widespread tissue damage, and respiratory failure. In clinical trials, inhibition of proinflammatory mediators has not proven effective. In this study, we pursued a new investigative strategy that emphasizes mediators promoting resolution from lung injury. A new spontaneously resolving experimental murine model of ALI from acid aspiration was developed to identify endogenous proresolving mechanisms. ALI increased cyclooxygenase 2 (COX-2) expression in murine lung. Selective pharmacologic inhibition or gene disruption of COX-2 blocked resolution of ALI. COX-2-derived products increased levels of the proresolving lipid mediators lipoxin A4 (LXA4) and, in the presence of aspirin, 15-epi-LXA4. Both LXA4 and 15-epi-LXA4 interact with the LXA4 receptor (ALX) to mediate anti-inflammatory actions. ALX expression was markedly induced by acid injury and transgenic mice with increased ALX expression displayed dramatic protection from ALI. Together, these findings indicate a protective role in ALI for COX-2-derived mediators, in part via enhanced lipoxin signaling, and carry potential therapeutic implications for this devastating clinical disorder.     

Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression

Tissue stiffening is a hallmark of fibrotic disorders but has traditionally been regarded as an outcome of fibrosis, not a contributing factor to pathogenesis. In this study, we show that fibrosis induced by bleomycin injury in the murine lung locally increases median tissue stiffness sixfold relative to normal lung parenchyma. Across this pathophysiological stiffness range, cultured lung fibroblasts transition from a surprisingly quiescent state to progressive increases in proliferation and matrix synthesis, accompanied by coordinated decreases in matrix proteolytic gene expression. Increasing matrix stiffness strongly suppresses fibroblast expression of COX-2 (cyclooxygenase-2) and synthesis of prostaglandin E₂ (PGE₂), an autocrine inhibitor of fibrogenesis. Exogenous PGE₂ or an agonist of the prostanoid EP2 receptor completely counteracts the proliferative and matrix synthetic effects caused by increased stiffness. Together, these results demonstrate a dominant role for normal tissue compliance, acting in part through autocrine PGE₂, in maintaining fibroblast quiescence and reveal a feedback relationship between matrix stiffening, COX-2 suppression, and fibroblast activation that promotes and amplifies progressive fibrosis.     

Calpain inhibitor I reduces the activation of nuclear factor-kappaB and organ injury/dysfunction in hemorrhagic shock.

There is limited evidence that inhibition of the activity of the cytosolic cysteine protease calpain reduces ischemia/reperfusion injury. The multiple organ injury associated with hemorrhagic shock is due at least in part to ischemia (during hemorrhage) and reperfusion (during resuscitation) of target organs. Here we investigate the effects of calpain inhibitor I on the organ injury (kidney, liver, pancreas, lung, intestine) and dysfunction (kidney) associated with hemorrhagic shock in the anesthetized rat. Hemorrhage and resuscitation with shed blood resulted in an increase in calpain activity (heart), activation of NF-kappaB (kidney), expression of iNOS and COX-2 (kidney), and the development of multiple organ injury and dysfunction, all of which were attenuated by calpain inhibitor I (10 mg/kg i.p.), administered 30 min prior to hemorrhage. Chymostatin, a serine protease inhibitor that does not prevent the activation of NF-kappaB, had no effect on the organ injury/failure caused by hemorrhagic shock. Pretreatment (for 1 h) of murine macrophages or rat aortic smooth muscle cells (activated with endotoxin) with calpain inhibitor I attenuated the binding of activated NF-kappaB to DNA and the degradation of IkappaBalpha, IkappaBbeta, and IkappaBvarepsilon. Selective inhibition of iNOS activity with L-NIL reduced the circulatory failure and liver injury, while selective inhibition of COX-2 activity with SC58635 reduced the renal dysfunction and liver injury caused by hemorrhagic shock. Thus, we provide evidence that the mechanisms by which calpain inhibitor I reduces the circulatory failure as well as the organ injury and dysfunction in hemorrhagic shock include 1) inhibition of calpain activity, 2) inhibition of the activation of NF-kappaB and thus prevention of the expression of NFkappaB-dependent genes, 3) prevention of the expression of iNOS, and 4) prevention of the expression of COX-2. Inhibition of calpain activity may represent a novel therapeutic approach for the therapy of hemorrhagic shock.     

Induction of cyclooxygenase-2 in reactive glial cells by the CD40 pathway: relevance to amyotrophic lateral sclerosis

An inflammatory process in association with reactive gliosis has been suggested to play an important role in the pathogenesis of amyotrophic lateral sclerosis (ALS). One of the key findings is a marked increase in the level of cyclooxygenase-2 (COX-2), a therapeutic target of ALS. We investigated the expression of CD40 in the spinal cord of a transgenic mouse model of ALS (G93A mice), and its relevance to COX-2 upregulation. CD40 was predominantly expressed in neurons in normal spinal cord and upregulated in reactive glial cells in spinal cord injury. In the spinal cord of G93A mice, the expression of CD40 was increased in both reactive microglia and astrocytes, where COX-2 was especially increased. The level of COX-2 was upregulated in microglia and astrocytes by CD40 stimulation in vitro. CD40 stimulation in primary spinal cord cultures caused motor neuron loss that was protected by selective COX-2 inhibitor. These results suggest that CD40, which is upregulated in reactive glial cells in ALS, participates in motor neuron loss via induction of COX-2.