2013-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/703776摘要：第2 型糖尿病現今已成為威脅全人類健康的一種疾病，目前第2 型糖尿病已被廣泛的認為與肥胖所導致的輕微慢性發炎有關。前列腺素E2 (PGE2)為調節發炎反應的重要媒介。其分解代謝是由NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (PGDH)進行氧化反應進而產生15-keto-PGE2。在先前的研究中，我們發現前列腺素還原酶(Prostaglandin Reductase 2, PTGR2) 具有催化15-keto-PGE2 還原成13,14-dihydro-15-keto-PGE2 的酵素活性。我們也發現15-keto-PGE2 是PPARγ的配體，其可藉由增進PPARγ轉錄活性而促進脂肪細胞分化；反之PTGR2 則具有抑制脂肪細胞分化的能力；而最近15-keto-PGE2 也被証實是內源性PPARγ的配體，並參與抗發炎作用。由於PGE2 及PPARγ在發炎反應中皆扮演了重要的角色，因而本計畫將研究PTGR2 及其受質15-keto-PGE2 參與發炎反應及其引起的代謝異常過程之可能。經由我們的初步研究發現，PTGR2 在PMA 所誘導分化的人類巨噬細胞中會大量表現，而進一步給予15-keto-PGE2 可誘使抗發炎的IL-10 生成增加(M2 活化巨噬細胞的功能)，但不會誘使發炎反應的細胞激素如TNF-α, IL-6 and IL-12 生成增加(M1 活化巨噬細胞的功能)。我們也發現15-keto-PGE2 部份藉由PPARγ訊息傳遞途徑來誘使IL-10 生成增加。這些結果暗示了15-keto-PGE2 和其分解酵素PTGR2 於調控抗發炎作用上占重要之角色，以及增強了前列腺素代謝反應在免疫反應調控上之重要性。因此我們將針對PTGR2進行以下的研究:(1) 其調控巨噬細胞分化過程以及轉換成M1 及M2 活化巨噬細胞的能力探討。(2) 其在巨噬細胞中所影響的下游基因及細胞激素的表現。(3) 其在巨噬細胞中所參與的訊息傳遞途徑。(4) 其在巨噬細胞及脂肪細胞中因自泌素及旁泌素作用在分泌細胞鄰近細胞的化學信使的角色。(5) 利用PTGR2 基因剔除鼠於肥胖疾病動物模式中，研究其在發炎及代謝異常的生理意義。(6) 利用PTGR2 抑製劑於小鼠模式中，研究其抗發炎能力。<br> Abstract: Type 2 diabetes has become epidemic which has a huge impact on human health.Chronic inflammation has been implied as an important etiology underlying obesity-relateddisorders such as insulin resistance and type 2 diabetes. Prostaglandin E2 (PGE2) is aprincipal mediator of inflammation in inflammatory diseases. It is a short-lived mediatorwhich is inactivated via an oxidation reaction catalyzed by NAD+-dependent15-hydroxyprostaglandin dehydrogenase (PGDH), which generates 15-keto-PGE2. In ourprevious publication, we found that prostaglandin reductase 2 (PTGR2) is an enzyme thatcatalyses the reduction of 15-keto-PGE2 into the downstream metabolite 13,14-dihydro-15-keto-PGE2. We also showed that 15-keto-PGE2 acts as a natural ligand ofPPARγwhich increases its transcriptional activation and hence promotes adipogenesis,while PTGR2 suppressed adipogenic function through repression of PPARγ activity.Recently, 15-keto-PGE2 has been confirmed as an endogenous PPARγligand whichparticipates in anti-inflammation in a mouse model of chronic inflammation.Given the important role of prostaglandins and PPARγ activity in inflammatory diseasesand the fact that PTGR2 is an enzyme in the eicosanoid metabolism, we hypothesize thatPTGR2 might play a distinct role in inflammation and obesity-related metabolic dysfuntions.In our preliminary study, we discovered that PTGR2 expression is significantly upregulatedin PMA-differentiated THP-1 macrophages. Furthermore, we found that 15-keto-PGE2 couldinduce the anti-inflammatory cytokine IL-10 production (a function of M2 macrophage), butnot the pro-inflammatory cytokines such as TNF-α, IL-6 and IL-12 (a function of M1macrophage). In addition, 15-keto-PGE2 induced IL-10 production was partially throughPPARγ-dependent pathway. Taken together, these findings implied that PTGR2 and itssubstrate 15-keto-PGE2 may play an important role in modulating inflammatory responseand inflammation-mediated metabolic disturbance. Therefore, in this proposal we plan tostudy the followings:1. To determine the role of PTGR2 in mediating macrophage differentiation into M1 andM2 activated macrophages.2. To study of the downstream affected genes and cytokines profiling mediated by PTGR2 inM1 or M2 macrophages.3. To study the downstream signaling pathways regulated by PTGR2 in activatingmacrophages.4. To explorer the role of PTGR2 in mediating the cross-talk between macrophages andadipocytes and its related metabolic disturbances.5. To study the physiological role of PTGR2 by using inflammation model (High-Fat Dietinduced obesity) in PTGR2-/- mice.6. Appling of PTGR2 inhibitors in mouse model to study its anti-inflammatory effect.前列腺素還原酶15-keto-PGE2發炎反應過氧化氫受體 γPTGR215-keto-PGE2inflammation,PPARγ