Sandulache Vlad C, Parekh Aron, Li-Korotky HaSheng, Dohar Joseph E, Hebda Patricia A
Division of Pediatric Otolaryngology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Wound Repair Regen. 2007 Jan-Feb;15(1):122-33. doi: 10.1111/j.1524-475X.2006.00193.x.
Keloid formation has been linked to aberrant fibroblast activity, exacerbated by growth factors and inflammatory mediators. Prostaglandin E2 (PGE2), synthesized from arachidonic acid by cyclooxygenases (COX) and synthases (PGES), acts as both an inflammatory mediator and fibroblast modulator. Although PGE2 has known antifibrotic effects in the lower airway, its role in dermal fibrosis in general, and keloid formation in particular, remains unclear. This study focused on: (1) the effects of PGE2 on keloid fibroblast migration, contraction, and collagen synthesis and (2) endogenous PGE2 synthesis in response interleukin-1beta. PGE2 decreased keloid fibroblast migration and contraction via an EP2/EP4-cAMP mechanism that disrupted actin cytoskeletal dynamics and reversed transforming growth factor-beta1-induced collagen I and III synthesis. Impaired fibroblast PGE2 production has been linked to lower airway fibrosis and recently to keloid formation. Here, we showed that interleukin-1beta stimulation leads to nuclear factor-kappaB translocation to the nucleus, resulting in up-regulation of COX-2 and microsomal PGE2 synthase 1. Up-regulation of COX-2 in, and secretion of PGE2 by keloid fibroblasts are diminished compared with their normal fibroblast counterparts. We suggest that the antifibrotic effects of PGE2 during keloid formation are potentially diminished due to aberrant paracrine fibroblast signaling. Exogenous PGE2 may supplement decreased endogenous levels and inhibit keloid formation or progression.
瘢痕疙瘩的形成与成纤维细胞异常活动有关,生长因子和炎症介质会加剧这种情况。前列腺素E2(PGE2)由环氧化酶(COX)和合成酶(PGES)从花生四烯酸合成,既是一种炎症介质,也是一种成纤维细胞调节剂。尽管PGE2在下呼吸道具有已知的抗纤维化作用,但其在一般皮肤纤维化,特别是瘢痕疙瘩形成中的作用仍不清楚。本研究聚焦于:(1)PGE2对瘢痕疙瘩成纤维细胞迁移、收缩和胶原蛋白合成的影响,以及(2)白细胞介素-1β刺激下内源性PGE2的合成。PGE2通过EP2/EP4-环磷酸腺苷(cAMP)机制降低瘢痕疙瘩成纤维细胞的迁移和收缩,该机制破坏肌动蛋白细胞骨架动力学,并逆转转化生长因子-β1诱导的I型和III型胶原蛋白合成。成纤维细胞PGE2产生受损与下呼吸道纤维化有关,最近还与瘢痕疙瘩形成有关。在这里,我们表明白细胞介素-1β刺激导致核因子-κB易位至细胞核,从而导致COX-2和微粒体PGE2合成酶1上调。与正常成纤维细胞相比,瘢痕疙瘩成纤维细胞中COX-2的上调以及PGE2的分泌减少。我们认为,由于旁分泌成纤维细胞信号异常,瘢痕疙瘩形成过程中PGE2的抗纤维化作用可能会减弱。外源性PGE2可能补充降低的内源性水平,并抑制瘢痕疙瘩的形成或进展。