Microvesicles as a Novel Transmitter for UVB-Induced Bioactive Products

项目摘要 紫外线B(UVB)辐射对皮肤有深远的影响，并产生全身 从发烧到免疫抑制再到维生素D产生的后果。仅作为UVB 穿透表皮，光生物学中的一个主要问题是UVB治疗后的皮肤如何发送 系统性信号。最近的研究表明，已知的小的膜结合囊泡 由于微泡颗粒(MVP)从细胞中释放出来，对各种应激源做出反应，可以起作用 由于它们能够携带细胞核和细胞质成分，因此被认为是有效的信号转导因子。 我们已经证明了UVB会从上皮细胞和皮肤中释放MVP，这是一种 为UVB介导的系统信号传导提供了一种潜在的机制。我们的团队和 其他人已经证明UVB辐射会产生高水平的脂质介体 酶促产生的血小板活化因子及其受体激动剂 通过活性氧产生的非酶类物质。使用抗氧化剂的最新研究 PAF-R表达/空细胞系参与UVB中PAF-R信号转导 已生成MVP(UVB-MVP)。设计了两个目标来检验UVB 在人体皮肤中以PAF依赖的方式产生MVP，并通过 它们携带着强大的信号分子。目标1将决定MVP是否从 UVB后的人体皮肤，以及这一过程是否依赖PAF-R。我们计划了三个 互补的方法。首先，我们将使用人类皮肤外植体来诱导 以水疱液为MVP来源的吸水泡及PAF-R的试验效果 拮抗剂/抗氧化剂。其次，我们会在受试者身上诱发吸入性水泡 使用/不使用全身性抗氧化剂，并使用UVB处理起泡屋顶。最后，我们将评估 用成对的人血(光疗前/后)在体内循环MVP 接受全身UVB治疗的患者。Aim 2将确定生物活性物质 在UVB-MVP中。MVP和细胞都将接受三类试剂的测试：脂质介体， 蛋白质细胞因子和microRNAs。该项目的成功完成将(I)解决 光生物学中的一个重要问题，即角质形成细胞特异性刺激如何产生 系统信号效应，(Ii)提供阻断UVB系统效应的药理机制。

Project Summary Ultraviolet B (UVB) radiation has profound effects upon skin and generates systemic consequences from fever to immunosuppression to vitamin D production. As UVB only penetrates the epidermis, a major question in photobiology is how UVB-treated skin sends systemic signals. Recent studies have indicated that small membrane-bound vesicles known as microvesicle particles (MVP) released from cells in response to various stressors can act as potent signaling agents due to their ability to carry nuclear and cytoplasmic components. We have demonstrated that UVB generates MVP release from epithelial cells and skin, which could provide a potential mechanism for UVB-mediated systemic signaling. Our group and others have demonstrated that UVB radiation generate high levels of the lipid mediator Platelet-activating factor (PAF) produced enzymatically and PAF-receptor (PAF-R) agonists produced non-enzymatically via reactive oxygen species. Recent studies using antioxidants and PAF-R-expressing/null cell lines have implicated involvement of PAF-R signaling in UVB generated MVP (UVB-MVP). Two aims are designed to test the hypothesis that UVB generates MVP in human skin in a PAF-dependent manner and transfers systemic effects via their carried potent signaling molecules. Aim 1 will determine if MVP are released from human skin following UVB and if this process is PAF-R dependent. We plan three complementary approaches. First, we will use human skin explants to induce multiple suction blisters with the blister fluid as source of MVP, and test effects of PAF-R antagonists/antioxidants. Second, we will induce suction blisters on human subjects with/without systemic antioxidants, and treat the blister roof with UVB. Finally, we will assess circulating MVP in vivo using paired blood draws (before/after phototherapy) from human patients undergoing whole body UVB treatment. Aim 2 will determine the bioactive agents in UVB-MVP. Both MVP and cells will be tested for three classes of agents: lipid mediators, protein cytokines and microRNAS. Successful completion of this project will (i) address an important question in photobiology as to how a keratinocyte-specific stimulus can generate systemic signaling effects, (ii) offer pharmacologic mechanisms to block UVB systemic effects.