Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
J Pathol. 2018 May;245(1):114-125. doi: 10.1002/path.5061. Epub 2018 Apr 2.
Bullous pemphigoid is an autoimmune inflammatory disorder characterized by the presence of autoantibodies against bullous pemphigoid autoantigens, leading to dermal-epidermal separation with consequent blister formation. However, whether and how the components of blister fluid exacerbate the progression of bullous pemphigoid is unclear. Exosomes are nanometre-sized vesicles released from cells into the body fluid, where they can transmit signals throughout the body. In the present study, we isolated and characterized exosomes from blister fluids of patients with bullous pemphigoid, evaluated their proinflammatory role, and identified the underlying molecular mechanisms. We found that exosomes isolated from blister fluids of patients with bullous pemphigoid showed the expected size and expressed the marker proteins CD63, CD81, and CD9. Additionally, blister fluid-derived exosomes were internalized by human primary keratinocytes, inducing the production of critical inflammatory cytokines and chemokines. Western blotting analysis showed robust and rapid activation of the extracellular signal-regulated kinase 1/2 and signal transducer and activator of transcription 3 signalling pathways in human primary keratinocytes after stimulation with blister fluid-derived exosomes. We also found that blister fluid-derived exosomes indirectly induced neutrophil trafficking by upregulating C-X-C motif chemokine ligand 8 in vitro. Furthermore, CD63 was localized mostly to keratinocytes and infiltrative granulocytes in skin lesions, suggesting that these cells were the possible sources of exosomes in blister fluid. Using mass spectrometry, we analysed the proteomes of blister fluid-derived exosomes and identified a variety of proteins implicated in inflammatory and immune responses. Together, our findings provide strong evidence that blister fluid-derived exosomes are involved in the local autoinflammatory responses of the skin associated with bullous pemphigoid. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
大疱性类天疱疮是一种自身免疫性炎症性疾病，其特征是存在针对大疱性类天疱疮自身抗原的自身抗体，导致真皮-表皮分离，继而形成水疱。然而，水疱液的成分是否以及如何加剧大疱性类天疱疮的进展尚不清楚。外泌体是细胞释放到体液中的纳米大小的囊泡，它们可以在全身传递信号。在本研究中，我们从大疱性类天疱疮患者的水疱液中分离和鉴定了外泌体，评估了它们的促炎作用，并确定了潜在的分子机制。我们发现，从大疱性类天疱疮患者水疱液中分离的外泌体表现出预期的大小，并表达了标记蛋白 CD63、CD81 和 CD9。此外，水疱液来源的外泌体被人原代角质形成细胞内化，诱导关键炎症细胞因子和趋化因子的产生。Western blot 分析显示，在刺激人原代角质形成细胞后，外泌体快速激活细胞外信号调节激酶 1/2 和信号转导和转录激活因子 3 信号通路。我们还发现，水疱液来源的外泌体通过体外上调 C-X-C 基序趋化因子配体 8 间接诱导中性粒细胞迁移。此外，CD63 主要定位于皮肤病变中的角质形成细胞和浸润性粒细胞，提示这些细胞可能是水疱液中外泌体的来源。通过质谱分析，我们分析了水疱液来源的外泌体的蛋白质组，并鉴定了多种参与炎症和免疫反应的蛋白质。总之，我们的研究结果提供了强有力的证据，表明水疱液来源的外泌体参与了与大疱性类天疱疮相关的皮肤局部自身炎症反应。
