Abstract：
Islets experience enormous stress during the isolation process, leading to suboptimal endocrine function after total pancreatectomy with islet autotransplantation (TPIAT). Our investigation focused on inducing isolation stress in islets ex vivo, where proinflammatory cytokines and hypoxia prompted the release of stress exosomes (exoS) sized between 50 and 200 nm. Mass spectrometry analysis revealed 3 distinct subgroups of immunogenic proteins within these exoS: damage-associated molecular patterns (DAMPs), chaperones, and autoantigens. The involvement of endosomal-sorting complex required for transport proteins including ras-associated binding proteins7A, ras-associated binding protein GGTA, vacuolar protein sorting associated protein 45, vacuolar protein sorting associated protein 26B, and the tetraspanins CD9 and CD63, in exoS biogenesis was confirmed through immunoblotting. Next, we isolated similar exoS from the islet infusion bags of TPIAT recipients (N = 20). The exosomes from infusion bags exhibited higher DAMP (heat shock protein family A [Hsp70] member 1B and histone H2B) levels, particularly in the insulin-dependent TPIAT group. Additionally, elevated DAMP protein levels in islet infusion bag exosomes correlated with increased insulin requirements (P = .010) and higher hemoglobin A1c levels 1-year posttransplant. A deeper exploration into exoS functionality revealed their potential to activate monocytes via the toll-like receptor 3/7: DAMP axis. This stimulation resulted in the induction of inflammatory phenotypes marked by increased levels of CD68, CD80, inducible nitric oxide synthase, and cyclooxygenase-2. This activation mechanism may impact the successful engraftment of transplanted islets.
摘要：
小岛在隔离过程中经历巨大的压力，导致胰岛自体移植全胰腺切除术（TPIAT）后内分泌功能欠佳。我们的研究集中在体外诱导胰岛隔离应激，其中促炎细胞因子和缺氧促进了大小在50-200nm之间的应激外泌体(exoss)的释放。质谱分析揭示了这些exoS中免疫原性蛋白的三个不同亚组：损伤相关分子模式（DAMPs），监护人,和自身抗原。转运（ESCRT）蛋白-RAB7A所需的内体分选复合物的参与，RABGGTA,VPS45,VPS26B,并通过免疫印迹证实了exoS生物发生中的四跨膜蛋白CD9和CD63-。接下来,我们从TPIAT接受者的胰岛输注袋中分离出相似的exoS(N=20)。来自输液袋的外泌体表现出更高的DAMP（HSPA1B，和组蛋白H2B）水平，特别是在胰岛素依赖性（ID）TPIAT组中。此外,胰岛输注袋外泌体中DAMP蛋白水平升高与移植后1年胰岛素需求量增加(p=0.010)和HbA1c水平升高相关.对exoS功能的更深入探索揭示了它们通过toll样受体TLR3/7:DAMP轴激活单核细胞的潜力。这种刺激导致诱导以CD68，CD80，iNOS，和COX-2。这种激活机制可能会影响移植胰岛的成功植入。
