光响应氧化锌负载AKBA防治多形性日光疹的效应及分子机制研究

Polymorphous light eruption (PLE), a common idiopathic photodermatosis, occurs following sun expose with itchy, edematous papules and vesicles. Its prevalence rate can reach 2% and 20% in Asian and Western countries respectively, and can severely impair the quality of life. It is currently most recognized as altered hyper immune response, as sunlight-induced delayed type hypersensitivity (DTH), yet pathogenesis need be further clarified, only limited treatment and prevention methods for this skin condition. We have found that the ZnO nanoparticle (NP) is light-responsive: it has the capacity to release encapsulated hydrophobic drug following UVA irradiation and restore them upon dark treatment, thus could be used for better sun protection. .UVA irradiation alter cellular oxidative stress related transcriptional repressor Bach1 (BTB and CNC-homology 1) and activator Nrf2 (Nuclear factor -erythroid (NF-E2)-related factor2) and their major down stream effector heme oxygenase1 (HO-1) in human skin cells; the anti-inflammatory acetyl-11-keto-beta-boswellic acid (AKBA) alters UVA-induced Bach1, Nrf2 and HO-1, COX-2, NF-κB, NOX-1 etc, with the reduction of UVA induced oxidative stress to in human skin keratinocytes HaCaT. Accordingly, we believe that AKBA may affect Bach1/HO-1 and they may play role in PLE since Bach1/HO-1 play roles in immune response and oxidative stress following UVA irradiation. .In this study, the effect of ZnO-AKBA NP in human skin cell lines, as well as in UVA induced PLE lesion in mice model will be evaluated. We will try to identify the Bach1/HO-1, and the HO-1 -Estrogen receptor-β (Erβ) signalling modulate UVA- PLE lesion via inflammatory factors (e.g. interleukin IL-6, 8, 10) or matrix metalloproteinase MMPs (e.g. MMP1, MMP9) and further understand their role in UVA cellular effects. This study will promote the understanding of the pathomechanism of PLE, and using better sun protection and effectiveness of treatment of photodermatosis such as PLE.

多形性日光疹(PLE)与紫外线引起的异常免疫反应相关，但具体分子机制不清，防治手段效果有限。UVA诱导的氧化损伤、超常免疫反应可能起重要作用。我们发现乳香酸(AKBA)通过调节UVA诱导的Bach1（体内氧化还原平衡中重要的负调控转录因子），以及HO-1，NF-κB、COX-2及NOX-1等表达以减少皮肤细胞氧化炎性损伤；且利用UVA进行光控氧化锌纳米颗粒(ZnO NP)运载药物以用于光防护。本课题先合成AKBA-ZnO NP，以人体角质细胞为主，结合PLE皮损动物模型及组织、细胞，研究UVA诱导上述分子的表达与PLE的相关性及机制，并探讨光控AKBA-ZnO NP对PLE皮损的防治效应。进一步弄清Bach1/HO-1与Erβ的相互作用所导致雄性和雌性鼠光损伤差异的机制。本项目有助于阐明光线性疾病如PLE的发病机制，并为其提供新的防治手段。

背景：紫外线照射导致氧化应激，引起皮肤细胞、组织损伤、炎症反应及致癌等，我们研究发现UVA照射引起HO-1剪切，形成核内tHO-1. .目的：初步完成AKBA的抗炎、抗氧化效应研究，以及AKBA纳米材料的包裹与UVA智能释放。进一步阐述了皮肤主要细胞中，UVA诱导剪切型血红素氧合酶表达机制。.方法：构建HO-1及Nrf2敲除细胞，以HaCaT细胞为主，UVA辐射后，分析细胞形态、细胞增殖、细胞内ROS水平检测及抗氧化酶表达。.结果：1）AKBA及圣草酚可调控Nrf2、Bach1及其靶基因HO-1、NQO1的表达，也可通过减少UVA 导致的炎症调节因子（COX-2，NFB）和NOX1的表达，进而减少UVA产生的氧化损伤，增加细胞的保护效应。总之，AKBA能通过调节炎症因子和ROS的产生来保护皮肤细胞免受UVA导致的损伤。我们进行了AKBA-ZnO纳米材料的合成、表征及初步机制研究。可为UVA智能释放抗氧化，抗炎药物，及预防与治疗光损伤及日光性疾病提供理论依据。.2）我们发现鸦胆子苦醇Brusatol（BR，Nrf2抑制剂）与低剂量的UVA联合处理黑色素瘤A375细胞，可抑制细胞增殖，G1期细胞周期阻滞及诱导细胞凋亡。同时，抑制Nrf2表达（包括BR处理及基因干扰）、细胞克隆形成及小鼠肿瘤生长等。另外，UVA与BR联合作用能够部分地抑制Nrf2下游基因的表达，如HO-1、GSTP1、NQO1，及抑制PI3K /AKT信号通路的激活；通过AKT-Nrf2信号通路增加ROS的产生，诱导细胞周期阻滞及细胞凋亡，抑制细胞增殖。.结论： AKBA通过减少炎症反应和ROS产生来保护皮肤细胞免受UVA引起的损伤。通过UVA照射引起AKBA-ZnO纳米材料的释放。防UVA光损伤研究，通过UVA光控释放药物，增加药物的效能及减少损耗。.关键词：UVA 辐射, 皮肤角质细胞, AKBA, Nrf2/Bach1, HO-1, NP-ZnO,光释放