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， 从发烧到免疫抑制再到维生素D的产生。仅作为UVB 穿透表皮，光生物学的一个主要问题是UVB处理的皮肤如何发送 系统信号。最近的研究表明，已知的小膜结合囊泡 由于响应于各种应激源从细胞释放的微泡颗粒（MVP）可以起作用， 由于它们能够携带细胞核和细胞质组分，因此可用作有效的信号传导剂。 我们已经证明UVB可以从上皮细胞和皮肤中释放MVP， 可能为UVB介导的系统信号传导提供潜在机制。本集团与 其他人已经证明UVB辐射产生高水平的脂质介质， 酶促产生的血小板活化因子（PAF）和PAF受体（PAF-R）激动剂 通过活性氧类非酶促产生。最近的研究使用抗氧化剂 和PAF-R表达/无效细胞系暗示了PAF-R信号转导在UVB中的参与 生成MVP（UVB-MVP）。设计了两个目标来验证UVB 以PAF依赖性方式在人体皮肤中产生MVP，并通过 它们携带着强有力的信号分子。目标1将决定MVP是否从 人皮肤在UVB之后，并且如果该过程是PAF-R依赖性的。我们计划三 互补的方法。首先，我们将使用人类皮肤移植物诱导多个 以水泡液为MVP源的吸引水泡，并测试PAF-R的效果 拮抗剂/抗氧化剂。第二，我们将在人类受试者身上诱导抽吸水泡 有/没有全身性抗氧化剂，并用UVB处理水泡顶部。最后，我们将评估 使用来自人的成对抽血（光疗之前/之后）的体内循环MVP 接受全身UVB治疗的患者。目的2确定生物活性剂 在UVB-MVP中。MVP和细胞都将测试三类试剂：脂质介质， 蛋白质细胞因子和microRNAS。该项目的成功完成将（i）解决 光生物学中一个重要问题是角质形成细胞特异性刺激如何产生 系统性信号传导作用，（ii）提供阻断UVB系统性作用的药理学机制。

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.