前列腺素E2在排卵过程中的作用

前列腺素E2主要由颗粒细胞合成，是大多数哺乳类动物排卵卵泡中关键的调节分子。前列腺素E2在排卵过程中具有重要作用。黄体生成激素激增，通过环氧合酶-2和前列腺素合酶，诱导颗粒细胞合成前列腺素E2，并释放到胞外后结合卵丘颗粒细胞上前列腺素E2受体2和前列腺素E2受体4。通过这些受体，前列腺素E2诱导丝裂原活化蛋白激酶磷酸化，增加胞内环磷酸腺苷水平并激活蛋白激酶B和丝裂原活化蛋白激酶通路，促进排卵过程的发生。前列腺素E2的调控异常与多种排卵障碍性疾病有关，如多囊卵巢综合征和未破裂卵泡黄素化综合征等。     

miR-9的靶蛋白在多囊卵巢综合征患者卵巢组织中的研究进展

多囊卵巢综合征(PCOS)是育龄女性最常见的一种生殖内分泌疾病,目前全世界育龄期女性的发病率占到4%~10%。PCOS具有异质性,其病理改变十分复杂,包括窦状卵泡发育异常、颗粒细胞增生凋亡、卵泡膜细胞过度增生、高雄激素血症及慢性排卵障碍等。至今具体发病机制尚未阐明,多基因异常和环境改变被认为是PCOS发病机制的两个重要因素。近年研究发现,微小核糖核酸(miRNA)异常表达与氧化应激、胰岛素抵抗、高雄激素血症、炎症以及各种癌症形成有关。研究显示,微小核糖核酸-9(miR-9)在PCOS患者卵泡液及卵巢颗粒细胞中的表达水平较健康妇女明显升高,考虑可能与PCOS的发病机制有关。通过KEGG database pathway及Target Scan等软件进行生物信息学分析结果提示miR-9主要的靶蛋白有核因子κB亚基1(NF-κB1)、肿瘤坏死因子-α(TNF-α)、丝裂原活化蛋白激酶14(MAPK14)、胰岛素受体底物2(IRS2)等。文本将对miR-9的靶蛋白在PCOS患者卵巢组织中的表达研究进展进行综述。     

参与骨关节炎的P38丝裂原活化蛋白激酶信号转导通路

背景：p38丝裂原活化蛋白激酶信号转导通路属于丝裂原活化蛋白激酶家族成员,在骨关节炎的发生发展中发挥重要作用。目的：对骨关节炎病理进程中 p38丝裂原活化蛋白激酶信号转导通路相关作用机制的研究进展进行综述。方法：由第一作者用计算机检索中国期刊全文数据库和 PubMed 数据库,检索词分别为“p38丝裂原活化蛋白激酶信号通路、骨关节炎、关节软骨、软骨细胞”和“p38MAPK signal transduction pathway, osteoarthritis, Articular cartilage,Chondrocyte”。从 p38丝裂原活化蛋白激酶信号通路简介,p38丝裂原活化蛋白激酶在骨关节炎中的作用,p38丝裂原活化蛋白激酶阻断剂在骨关节炎中的应用3方面进行总结。共检索到可应用文献90篇,按纳入标准对文献进行筛选,共纳入46篇文章。结果与结论：p38丝裂原活化蛋白激酶信号通路与软骨细胞的肥大化和钙化、软骨细胞的凋亡、软骨基质金属蛋白酶的合成、软骨炎性细胞因子的产生等有密切关系,对骨关节炎的发生发展有重要影响。p38丝裂原活化蛋白激酶通过多种复杂的机制参与骨关节炎的形成和发展,对其起到极其重要的作用,因此阻断 p38丝裂原活化蛋白激酶信号通路可能成为骨关节炎治疗的新靶点。     

表皮生长因子对卵巢激活素基因表达的调节及其信号通路(英文)

背景:激活素作为卵巢内调控分子,对卵巢卵泡发育起着重要作用。目的:探索表皮生长因子在激活素基因表达过程中所起的重要作用以及可能参与调节的信号通路。方法:分离斑马鱼卵巢卵泡,体外培养6d,消化后传代培养24h。表皮生长因子单独或与其他分子抑制剂(AG1478、H89、GF109203X)或激动剂(FK、PMA)联合处理细胞,提取细胞RNA,反转录PCR检测细胞激活素表达量。结果与结论:表皮生长因子可快速提高激活素表达量,其作用可能是通过磷酸化信号分子丝裂原活化蛋白激酶实现,而蛋白激酶C特异性抑制剂或激动剂可减弱或加强表皮生长因子对丝裂原活化蛋白激酶信号分子的激活,显示卵巢内激活素表达受表皮生长因子调节,蛋白激酶C/丝裂原活化蛋白激酶信号通路参与了这种调节作用。蛋白激酶A抑制剂也能抑制表皮生长因子对激活素表达的促进作用。     

表皮生长因子对卵巢激活素基因表达的调节及其信号通路

背景：激活素作为卵巢内调控分子,对卵巢卵泡发育起着重要作用。目的：探索表皮生长因子在激活素基因表达过程中所起的重要作用以及可能参与调节的信号通路。方法：分离斑马鱼卵巢卵泡,体外培养6d,消化后传代培养24h。表皮生长因子单独或与其他分子抑制剂（AG1478、H89、GF109203X）或激动剂（FK、PMA）联合处理细胞,提取细胞RNA,反转录PCR检测细胞激活素表达量。结果与结论：表皮生长因子可快速提高激活素表达量,其作用可能是通过磷酸化信号分子丝裂原活化蛋白激酶实现,而蛋白激酶C特异性抑制剂或激动剂可减弱或加强表皮生长因子对丝裂原活化蛋白激酶信号分子的激活,显示卵巢内激活素表达受表皮生长因子调节,蛋白激酶C/丝裂原活化蛋白激酶信号通路参与了这种调节作用。蛋白激酶A抑制剂也能抑制表皮生长因子对激活素表达的促进作用。     

脂多糖诱导肝细胞HMGB1释放及其信号通路研究

目的研究脂多糖对肝细胞高迁移率族蛋白B1（HMGB1）释放的诱导作用及其胞内信号通路。方法采用正常大鼠肝细胞BRL-3A培养,观察100ug／L脂多糖诱导不同时间后细胞HMGB1 mRNA表达水平和细胞培养上清液中HMGB1含量的变化,及不同浓度的丝裂原活化蛋白激酶信号通路抑制剂SB202190、U0126对其诱导作用的影响。HMGB1含量采用酶联免疫吸附试验检测。结果脂多糖诱导BRL-3A肝细胞6h后HMGB1 mRNA表达水平和培养上清液中HMGB1含量明显升高（P〈0．01）,后者随着诱导时间延长而进一步升高;20umol／LSB202190和20umol／LU0126对脂多糖诱导HMGB1胞外释放有不完全的抑制作用,但对HMGB1 mNNA表达无影响。结论内毒素脂多糖诱导肝细胞HMGB1的mRNA表达和胞外释放,丝裂原活化蛋白激酶信号通路参与其释放过程。     

运动对骨骼肌丝裂原活化蛋白激酶信号系统的影响

背景:丝裂原活化蛋白激酶是生物体内重要的信号转导系统之一,参与介导生长、发育、分裂、分化、死亡以及细胞间的功能同步等多种细胞过程.目的:总结丝裂原活化蛋白激酶对运动后骨骼肌适应性变化的重要作用.方法:采用计算机检索中国期刊全文数据及PubMed数据库1990-01/2009-06期间的相关文章,检索词为"运动;丝裂原活化蛋白激酶信号系统;骨骼肌;适应,Exercise;Mitogen-activated protein kinases;skeletal muscle;adaption".纳入与运动和丝裂原活化蛋白激酶信号系统研究现状与发展密切相关的文章,排除重复性研究.结果与结论:运动能够激活骨骼肌中丝裂原活化蛋白激酶信号传导系统,不同运动方式、不同类型的肌肉以及训练的时间长短都可以影响到丝裂原活化蛋白激酶的激活,而且激活后丝裂原活化蛋白激酶具有不同的时相性,丝裂原活化蛋白激酶对运动后骨骼肌的适应性变化具有重要作用.通过研究探索丝裂原活化蛋白激酶对运动后骨骼肌的适应性变化,有利于以运动相关的丝裂原活化蛋白激酶为靶点,研制和开发运动功能性食品或抗疲劳药物.     

体内外不同环境下成纤维细胞丝裂素原激活蛋白激酶的变化

目的:观察脱离体内环境因素时成纤维细胞中信号蛋白表达及细胞生物学特性的变化。方法:瘢痕疙瘩和正常皮肤(作为阴性对照)均来自北京大学第三医院成形科手术患者各6例。取小块瘢痕疙瘩和正常皮肤组织,用组织块接种法进行成纤维细胞原代培养后,进行细胞传代。试验所用为第5～8代细胞。①评价信号蛋白的含量,用体外培养的瘢痕疙瘩和正常皮肤成纤维细胞中p44/42丝裂原活化蛋白激酶和磷酸化的p44/42丝裂原活化蛋白激酶的积分吸光度值。②评价信号蛋白的活化强度,用体外培养的瘢痕疙瘩和正常皮肤成纤维细胞中p44/42丝裂原活化蛋白激酶和磷酸化的p44/42丝裂原活化蛋白激酶的平均积分吸光度值。③评价信号蛋白的活化程度用活化率值(磷酸化的p44/42丝裂原活化蛋白激酶积分吸光度值÷p44/42丝裂原活化蛋白激酶积分吸光度值)。结果:①p44/42丝裂原活化蛋白激酶和磷酸化的p44/42丝裂原活化蛋白激酶平均积分吸光度值比较:瘢痕疙瘩成纤维细胞均低于正常皮肤成纤维细胞(0.023±0.005和0.025±0.005,0.030±0.000和0.042±0.004,P<0.05)。②p44/42丝裂原活化蛋白激酶和磷酸化的p44/42丝裂原活化蛋白激酶积分吸光度值比较:瘢痕疙瘩成纤维细胞p44/42丝裂原活化蛋白激酶高于正常皮肤成纤维细胞(6048.7±1576.2,3006.3±174.4,P<0.05),瘢痕疙瘩成纤维细胞磷酸化的p44/42丝裂原活化蛋白激酶与正常皮肤成纤维细胞无差异(4876.0±895.8,3966.5±533.1,P>0.05)。③p44/42丝裂原活化蛋白激酶和磷酸化的p44/42丝裂原活化蛋白激酶活化率比较:瘢痕疙瘩成纤维细胞低于正常皮肤成纤维细胞(0.830±0.134,1.319±0.156,P<0.05)。结论:成纤维细胞在脱离生物体内环境后,其生物学特性发生改变。体外细胞培养中,磷酸化的p44/42丝裂原活化蛋白激酶的表达水平在瘢痕疙瘩和正常皮肤成纤维细胞间无明显差别,而p44/42丝裂原活化蛋白激酶的活化程度和活化强度在正常皮肤成纤维细胞明显高于瘢痕疙瘩成纤维细胞。     

COX-2在女性生殖过程中的作用

环氧合酶(COX)是前列腺素合成过程中一个重要的限速酶，参与了前列腺素及其衍生物的合成，其两种同工酶：COX-1和COX-2在女性生殖系统中都有表达；其中COX-2通过这些衍生物参与或调节女性排卵、受精、种植和蜕膜化等生殖相关过程；并且可以设想作为卵泡和胚胎发育的预测因素之一，有利于辅助生殖技术的提高。     

阿托伐他汀对单侧输尿管梗阻大鼠肾小管间质丝裂原活化蛋白激酶p38活性的影响

目的:观察单侧输尿管梗阻大鼠肾小管间质丝裂原活化蛋白激酶p38、磷酸化丝裂原活化蛋白激酶p38的表达变化,分析丝裂原活化蛋白激酶p38在肾小管间质纤维化发生中的作用及阿托伐他汀抗肾小管间质纤维化的可能机制。方法:实验于2004-09/2005-03在泸州医学院附属医院传染免疫研究室内完成。清洁级SD大鼠45只,数字表法随机分为假手术组、模型组及阿托伐他汀治疗组(简称阿乐组),每组15只。模型组与阿乐组大鼠均行单侧输尿管梗阻术,假手术组仅游离输尿管但不结扎。阿乐组于术前3d开始阿托伐他汀10mg/(kg·d)(混悬于1mL生理盐水中)灌胃,其余两组予等量生理盐水灌胃。术后第5,10,15天分别处死各组中的5只大鼠,取左肾行苏木精-伊红染色和Masson染色,并用免疫组化方法检测肾小管间质中转化生长因子β1、丝裂原活化蛋白激酶p38、P-丝裂原活化蛋白激酶p38的表达。结果:SD大鼠45只全部进入结果分析。①模型组大鼠肾小管间质细胞增多,肾小管基底膜增厚皱缩,纤维化明显,随时间进展而加重;阿乐组大鼠肾小管间质病变程度较同期模型组明显减轻(P<0.01)。②假手术组大鼠肾小管间质中仅有少量转化生长因子β1、丝裂原活化蛋白激酶p38、P-丝裂原活化蛋白激酶p38表达;术后5,10,15d模型组大鼠梗阻侧肾小管间质中转化生长因子β1、丝裂原活化蛋白激酶p38、P-丝裂原活化蛋白激酶p38表达量为较假手术组明显增加(P<0.01),且随时间进展,表达量不断增加;阿乐组均较同期模型组明显减轻(P<0.01)。③实验大鼠肾小管间质丝裂原活化蛋白激酶p38、P-丝裂原活化蛋白激酶p38表达与转化生长因子β1表达均呈正相关(r=0.436,0.432,P<0.01);P-丝裂原活化蛋白激酶p38表达与丝裂原活化蛋白激酶p38表达呈正相关(r=0.447,P<0.01)。结论:丝裂原活化蛋白激酶p38可能参与单侧输尿管梗阻大鼠肾小管间质纤维化过程,阿托伐他汀可能是通过抑制丝裂原活化蛋白激酶p38活性而达到抗肾小管间质纤维化作用的。     

Effects of florfenicol on LPS-induced nitric oxide and prostaglandin E₂ production in RAW 264.7 macrophages

Florfenicol, an antibiotic commonly used to treat infections, has previously been shown to modulate lipopolysaccharide (LPS)‐induced early cytokine responses by blocking the nuclear factor‐κB (NF‐κB) pathway. In this study, we investigated the effects of florfenicol on nitric oxide (NO) and prostaglandin E₂ (PGE₂) production as well as on inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) expression in LPS‐stimulated murine RAW 264.7 macrophages. We also analysed the effects of florfenicol on mitogen‐activated protein kinase (MAPK) pathways. Florfenicol significantly inhibited LPS‐induced NO and PGE₂ production. Consistent with these observations, mRNA and protein expression of iNOS and COX‐2 were also inhibited by florfenicol in a dose‐dependent manner. Furthermore, phosphorylation of p38 and extracellular signal‐regulated kinase 1/2 (ERK1/2) in LPS‐stimulated RAW 264.7 cells was suppressed by florfenicol. However, c‐Jun N‐terminal kinase (JNK) phosphorylation remained unaffected. Using specific inhibitors of ERK and p38, we found that florfenicol may inhibit NO and PGE₂ mostly through ERK and p38 pathway. These results suggest that florfenicol inhibits NO and PGE₂ production in conjunction with an inhibition of iNOS and COX‐2 expression, at least partially via suppression of ERK1/2 and p38 MAPK phosphorylation.     

Lipid mediators in innate immunity against tuberculosis: opposing roles of PGE2 and LXA4 in the induction of macrophage death

Virulent Mycobacterium tuberculosis (Mtb) induces a maladaptive cytolytic death modality, necrosis, which is advantageous for the pathogen. We report that necrosis of macrophages infected with the virulent Mtb strains H37Rv and Erdmann depends on predominant LXA₄ production that is part of the antiinflammatory and inflammation-resolving action induced by Mtb. Infection of macrophages with the avirulent H37Ra triggers production of high levels of the prostanoid PGE₂, which promotes protection against mitochondrial inner membrane perturbation and necrosis. In contrast to H37Ra infection, PGE₂ production is significantly reduced in H37Rv-infected macrophages. PGE₂ acts by engaging the PGE₂ receptor EP2, which induces cyclic AMP production and protein kinase A activation. To verify a role for PGE₂ in control of bacterial growth, we show that infection of prostaglandin E synthase (PGES)^−/− macrophages in vitro with H37Rv resulted in significantly higher bacterial burden compared with wild-type macrophages. More importantly, PGES^−/− mice harbor significantly higher Mtb lung burden 5 wk after low-dose aerosol infection with virulent Mtb. These in vitro and in vivo data indicate that PGE₂ plays a critical role in inhibition of Mtb replication.     

Targeting human inducible regulatory T cells (Tr1) in patients with cancer: blocking of adenosine–prostaglandin E2 cooperation

Introduction: Emerging data suggest that human inducible regulatory T cells (Tr1) produce adenosine and prostaglandin E₂ and that these factors cooperate in mediating immune suppression.

Areas covered: Human Tr1 present in human tumors or blood of cancer patients express ectonucleotidases, CD39 and/or CD73, hydrolyze ATP to adenosine and are COX-2 positive. Expression of CD39 and/or CD73 on human tumors favors expansion and suppressor functions of Tr1. Adenosine and PGE₂ signal via adenosine 2A receptor (A_2AR) and prostaglandin E₂ receptor 2 (EP₂R) expressed on effector T (Teff) cells, suppressing their anti-tumor functions by a common mechanism involving upregulation of cytosolic cAMP levels and protein kinase A (PKA) type I activation. The frequency and activity of circulating CD4⁺CD39⁺ and CD4⁺COX-2⁺ Treg subsets increase in advanced disease and also following oncologic therapies.

Expert opinion: Pharmacologic blocking of adenosine–PGE₂ collaboration provides a clinically-feasible strategy for disarming of Treg. Used in conjunction with conventional anti-cancer drugs or immune interventions, pharmacologic inhibitors could improve outcome of oncologic therapies.     

Different Protein Tyrosine Kinases Are Required for B Cell Antigen Receptor–mediated Activation of Extracellular Signal–Regulated kinase,c-Jun NH2-terminal Kinase 1, and p38 Mitogen-activated Protein Kinase

B cell antigen receptor (BCR) cross-linking activates three distinct families of nonreceptor protein tyrosine kinases (PTKs): src-family kinases, Syk, and Btk; these PTKs are responsible for initiating downstream events. BCR cross-linking in the chicken DT40 B cell line also activates three distinct mitogen-activated protein kinases (MAPKs): extracellular signal–regulated kinase (ERK)2, c-jun NH₂-terminal kinase (JNK)1, and p38 MAPK. To dissect the functional roles of these PTKs in MAPK signaling, activation of MAPKs was examined in various PTK-deficient DT40 cells. BCR-mediated activation of ERK2, although maintained in Lyn-deficient cells, was abolished in Syk-deficient cells and partially inhibited in Btk-deficient cells, indicating that BCR-mediated ERK2 activation requires Syk and that sustained ERK2 activation requires Btk. BCR-mediated JNK1 activation was maintained in Lyn-deficient cells but abolished in both Syk- and Btk-deficient cells, suggesting that JNK1 is activated via a Syk- and Btk-dependent pathway. Consistent with this, BCR-mediated JNK1 activation was dependent on intracellular calcium and phorbol myristate acetate–sensitive protein kinase Cs. In contrast, BCR-mediated p38 MAPK activation was detected in all three PTK-deficient cells, suggesting that no single PTK is essential. However, BCR-mediated p38 MAPK activation was abolished in Lyn/Syk double deficient cells, demonstrating that either Lyn or Syk alone may be sufficient to activate p38 MAPK. Our data show that BCR-mediated MAPK activation is regulated at the level of the PTKs.     

ASK1-p38 cascaded signal mediates pulmonary microvascular endothelial barrier injury induced by the return of PHSML in rats

The return of post-hemorrhagic shock mesenteric lymph (PHSML) induces pulmonary vascular endothelial barrier dysfunction, which results in acute lung injury. Activation of the apoptosis signal-regulated kinase 1 (ASK1) and p38 mitogen-activated protein kinase (p38 MAPK) pathway has been shown to trigger inflammatory responses. However, whether the ASK1-p38 MAPK pathway is involved in the PHSML-induced pulmonary endothelial barrier dysfunction remains unclear. In the present study, permeability changes of pulmonary capillaries were found in vivo, and activation of the ASK1-p38 MAPK pathway was determined in vitro. PMVEC barrier dysfunction was determined by measuring TEER. Furthermore, junctional and cytoskeletal protein expressions were analyzed. The results showed that hemorrhagic shock led to a marked increase in the permeability of pulmonary capillaries in vivo, which was markedly alleviated by PHSML drainage. In cultured pulmonary microvascular endothelial cells (PMVECs), PHSML reduced the endothelial barrier function accompanied by upregulated p-ASK1 and p-p38 MAPK protein expression, impaired the cytoskeletal protein structure, and down-regulated junction protein expression. These adverse effects were eliminated by applying either Trx1 (ASK1 inhibitor) or SB203580 (p38 MAPK inhibitor). These results indicated that the ASK1-p38 MAPK pathway mediates PHSML-induced pulmonary vascular endothelial barrier dysfunction during hemorrhagic shock.

The return of post-hemorrhagic shock mesenteric lymph (PHSML) induces pulmonary vascular endothelial barrier dysfunction, which results in acute lung injury.     

Hormone-like activity of a thymus humoral factor on the induction of immune competence in lymphoid cells

Experiments reported here were performed to understand the mechanism by which THF increases the immunocompetence of spleen cells from NTx mice. Dibutyryl cAMP or substances which increase intracellular levels of cAMP in lymphocytes such as Poly(A:U), theophylline, or PGE₂ were shown to mimic the effect of THF and confer reactivity in an in vitro GvH response to spleen cells from NTx mice. Flufenamic acid, an antagonist to PGE₂, was shown to inhibit the induction of competence by this substance. It was found that THF induces competence by activating membranal adenyl cyclase which leads to a rise in intracellular cAMP in thymus-derived cells only. These biochemical changes occur before antigenic stimulation and are unrelated to antigenic challenge. These findings indicate that THF exerts its effect via cAMP and are in agreement with the concepts which permit to classify THF as a thymus hormone.     

Differential central pain processing following repetitive intramuscular proton/prostaglandin E2 injections in female fibromyalgia patients and healthy controls

Background: While the etiology of fibromyalgia syndrome (FMS) remains unclear, it is assumed that both peripheral and central components are involved. Aims/methods: To investigate central activation patterns following chemically‐induced muscle pain we repetitively injected protons (low pH) and prostaglandin E₂ (PGE₂) in isotonic solution into the left extensor carpi radialis brevis muscle of female FMS patients and female healthy control subjects (HC). The injection of protons/PGE₂ has the advantage that it is not prone to tachyphylaxis compared to capsaicin and hypotonic saline solution. During the repetitive injections continuous pain ratings were recorded and functional magnetic resonance imaging measurements were conducted. Results: Injection of protons/PGE₂ led to activation of the anterior and medial cingulate cortices, contralateral primary sensory cortex, bilateral insula and thalamus, left basal ganglia, left orbitofrontal cortex and the cerebellum in FMS patients. In HC, activations were found only in the anterior, medial, and posterior cingulate cortices, and the primary somatosensory cortex. The contrast between the groups revealed significantly stronger activation for FMS patients in the left anterior insula. Peak pain ratings were comparable between HC and FMS patients, but pain duration (sustained pain) was prolonged in FM. Conclusion: Repetitive proton/PGE₂‐induced excitation of muscle tissue led to a more prolonged perception of pain and more wide‐spread activation in pain‐related brain areas in FMS, especially in the left (ipsilateral) insula, whereas acute protons/PGE₂‐induced pain processing was similar in the two groups. These data provide further evidence for enhanced central pain processing in FMS patients.     

COX-2 and iNOS are critical in advanced glycation end product-activated chondrocytes in vitro

Background The advanced glycation end products (AGEs) accumulate in joints of osteoarthritis patients. This study aimed to investigate the roles of cyclooxygenase‐2 (COX‐2) and inducible nitric oxide synthase (iNOS) pathways in AGE‐mediated cartilage damage. Materials and methods Methylglyoxal‐modified albumin was used as the source of AGE. Porcine and human chondrocytes were prepared from the joint cartilage of pigs and osteoarthritis patients. The activation of COX‐2, iNOS, nuclear factor‐kappaB (NF‐κB), activator protein‐1 (AP‐1) and protein kinases was determined by Western blotting, kinase assay, electrophoretic mobility shift assay (EMSA) or transfection assay. Prostaglandin E₂ (PGE₂) and NO concentrations were determined by enzyme‐linked immunosorbent assay (ELISA) and Griess reaction respectively. The enzymatic activity of COX was determined by measuring the conversion of arachidonic acid to PGE₂. The release of sulphated glycosaminoglycan and the intensity of Safranin O staining were used to measure cartilage degradation. Results AGE potently induced COX‐2‐PGE₂ and iNOS‐NO activation in porcine and human chondrocytes. Meanwhile, the upstream molecules regulating COX‐2/iNOS activation, such as AP‐1, NF‐κB, extracellular signal regulated protein kinase (ERK) and c‐jun N‐terminal kinase (JNK), were activated by AGE. Although AGE could not activate p38 directly, by measuring COX enzyme activity, the inhibition of p38 resulted in suppressing AGE‐induced conversion of arachidonic acid to PGE₂. Furthermore, successful blockage of either COX‐2 or NOS activity significantly reduced AGE‐mediated proteoglycan release and cartilage degradation. Conclusions This study highlights the significance of COX‐2 and iNOS pathways in AGE‐mediated OA pathogenesis and their potential as therapeutic targets that are beyond pain killing for OA treatment.