Kono Hiroshi, Furuya Shinji, Amemiya Hidetake, Hosomura Naohiro, Ichikawa Daisuke
First Department of Surgery, Faculty of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan.
Shock. 2025 Jun 23. doi: 10.1097/SHK.0000000000002658.
Acute lung injury (ALI) is a common cause of morbidity in patients with severe sepsis. Exosomes (EXOs) have been reported to induce ALI after severe hemorrhagic shock; therefore, this study aimed to investigate the role of EXOs isolated from the blood of septic rats with ALI.
Blood samples and lung tissues were collected from rats undergoing cecal ligation and puncture (CLP). EXOs were isolated by centrifugation from the blood of rats undergoing CLP and administered intravenously to normal rats, and 12 h after administration, lung tissues were harvested. Pathophysiological changes in the lung, the lung wet/dry weight ratio, and the lung microvascular permeability were assessed. Plasma inflammatory cytokines, namely tumor necrosis factor (TNF)-a, interleukin-6, and high-mobility group box chromosomal protein 1, were measured by enzyme-linked immunosorbent assay. In addition, lung microthrombosis was evaluated by immunohistochemistry. To investigate the effects of EXOs on tissue macrophages (Mfs), the production of TNF-a by isolated tissue Mfs was assessed in the presence or absence of EXOs in vitro.
Interstitial pulmonary edema, inflammatory cell infiltration, microhemorrhage, and microthrombosis were observed in the lung after CLP. Similar pathophysiological changes were observed in normal rats administered EXOs, although the extent of these changes was less severe than that in rats undergoing CLP. After EXO administration, the lung wet/dry ratio, lung microvascular permeability, and plasma inflammatory cytokine levels increased. The production of TNF-a by tissue Mfs increased during coculture with EXOs, blocked by anti-toll-like receptor 4 antibodies in the media. Furthermore, TNF-a production significantly decreased in EXO-stimulated cells treated with Triton X or proteinase K, suggesting that the surface protein and lipid fraction were most likely primary determinants.
EXOs isolated from the blood of septic rats trigger ALI by increasing inflammatory mediators.
急性肺损伤（ALI）是严重脓毒症患者发病的常见原因。据报道，外泌体（EXOs）在严重失血性休克后可诱发ALI；因此，本研究旨在探讨从患有ALI的脓毒症大鼠血液中分离出的外泌体的作用。
从接受盲肠结扎和穿刺（CLP）的大鼠中采集血液样本和肺组织。通过离心从接受CLP的大鼠血液中分离出外泌体，并静脉注射给正常大鼠，给药12小时后，采集肺组织。评估肺的病理生理变化、肺湿/干重比和肺微血管通透性。通过酶联免疫吸附测定法测量血浆炎症细胞因子，即肿瘤坏死因子（TNF）-α、白细胞介素-6和高迁移率族蛋白B1。此外，通过免疫组织化学评估肺微血栓形成。为了研究外泌体对组织巨噬细胞（Mfs）的影响，在体外有或无外泌体存在的情况下评估分离的组织Mfs产生TNF-α的情况。
CLP后肺中观察到间质性肺水肿、炎性细胞浸润、微出血和微血栓形成。在给予外泌体的正常大鼠中也观察到类似的病理生理变化，尽管这些变化的程度比接受CLP的大鼠轻。给予外泌体后，肺湿/干比、肺微血管通透性和血浆炎症细胞因子水平升高。与外泌体共培养期间，组织Mfs产生TNF-α增加，培养基中的抗Toll样受体4抗体可阻断这种增加。此外，用Triton X或蛋白酶K处理的外泌体刺激的细胞中TNF-α产生显著降低，表明表面蛋白和脂质部分很可能是主要决定因素。
从脓毒症大鼠血液中分离出的外泌体通过增加炎症介质引发ALI。
