Reyes-Martin Patricia, Ramirez-Rubio Sara, Parra-Cid Trinidad, Bienes-Martínez Raquel, Lucio-Cazana Javier
Department of Physiology, University of Alcala, Alcala de Henares, Madrid 28871, Spain.
Pharmacol Res. 2008 May;57(5):344-50. doi: 10.1016/j.phrs.2008.03.007. Epub 2008 Mar 26.
15-Deoxy-delta12,14-prostaglandin-J(2) (15d-PGJ(2)) has potent anti-inflammatory effects including the inhibition of interleukin-1beta (IL-1beta)-induced expression of cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)) production in several cell types. 15d-PGJ(2) contains an alpha,beta-unsaturated electrophilic ketone and several evidences suggest that thiol reducing agents prevent or revert the cellular effects of 15d-PGJ(2). The present study was devoted to analyze the effect of 15d-PGJ(2) on COX-2 expression in cultured human mesangial cells (HMC). 15d-PGJ(2) induced an increase in the reduced glutathione (GSH) content and up-regulated COX-2 protein expression, but not COX-1, in a manner which was unaffected by selective peroxisome proliferator-activated receptor gamma (PPARgamma) blockade nor mimicked by ciglitazone, a PPARgamma agonist. N-acetylcysteine (NAC), a thiol reducing agent, but not reactive oxygen species scavengers, prevented 15d-PGJ(2)-induced COX-2 up-regulation. Depletion of GSH by buthionine sulfoximine, which diminishes thiol antioxidant activity, cooperated with 15d-PGJ(2) to accumulate COX-2. Therefore, 15d-PGJ(2) up-regulated COX-2 through a thiol antioxidant-sensitive mechanism. Interestingly, NAC did not inhibit the COX-2 expression induced by the electrophilic alpha,beta-unsaturated compound PGA(2). Up-regulation of COX-2 by 15d-PGJ(2) did not result in increased PGE(2) production. Furthermore, preincubation with 15d-PGJ(2) inhibited IL-1beta-induced PGE(2) production although IL-1beta-induced COX-2 expression remained unaffected by the treatment with 15d-PGJ(2). On the contrary, PGA(2) elicited an increase in PGE(2) production and it acted synergistically with IL-1beta to enhance PGE(2) production. These results indicate for the first time that 15d-PGJ(2) inhibits PGE(2) production independently of its effect on COX-2 expression.
15-脱氧-Δ12,14-前列腺素-J2（15d-PGJ2）具有强大的抗炎作用，包括在多种细胞类型中抑制白细胞介素-1β（IL-1β）诱导的环氧化酶-2（COX-2）表达和前列腺素E2（PGE2）生成。15d-PGJ2含有α,β-不饱和亲电酮，多项证据表明硫醇还原剂可预防或逆转15d-PGJ2的细胞效应。本研究致力于分析15d-PGJ2对培养的人系膜细胞（HMC）中COX-2表达的影响。15d-PGJ2导致还原型谷胱甘肽（GSH）含量增加，并上调COX-2蛋白表达，但不影响COX-1，其作用方式不受选择性过氧化物酶体增殖物激活受体γ（PPARγ）阻断的影响，也不能被PPARγ激动剂吡格列酮模拟。硫醇还原剂N-乙酰半胱氨酸（NAC）可预防15d-PGJ2诱导的COX-2上调，而活性氧清除剂则无此作用。丁硫氨酸亚砜胺消耗GSH，降低硫醇抗氧化活性，与15d-PGJ2协同作用使COX-2积聚。因此，15d-PGJ2通过硫醇抗氧化剂敏感机制上调COX-2。有趣的是，NAC不抑制亲电α,β-不饱和化合物PGA2诱导的COX-2表达。15d-PGJ2上调COX-2并未导致PGE2生成增加。此外，用15d-PGJ2预孵育可抑制IL-1β诱导的PGE2生成，尽管IL-1β诱导的COX-2表达不受15d-PGJ2处理的影响。相反，PGA2可引起PGE2生成增加，并与IL-1β协同作用增强PGE2生成。这些结果首次表明，15d-PGJ2抑制PGE2生成与其对COX-2表达的影响无关。
