Department of Burns, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Department of Minimally Invasive Surgery, Thirds Hospital of Bengbu, Bengbu, Anhui, China.
J Chin Med Assoc. 2019 Dec;82(12):895-901. doi: 10.1097/JCMA.0000000000000189.
The aim of this study was to investigate the molecular mechanism of human umbilical cord mesenchymal stem cells (MSCs)-derived exosomes (hUCMSC-Exos) in regulating burn-induced acute lung injury (ALI).
In this study, we initially isolated exosomes from hUCMSCs and identified them by transmission electron microscopy. The expression of the protein markers CD9 and CD63 in the exosomes was determined by western blot analysis. The expression of miR-451 in the hUCMSC-Exos was determined by qRT-PCR. The levels of TNF-α, IL-1β, and IL-6 in lung tissues and serum as well as the levels of malondialdehyde, myeloperoxidase, superoxide dismutase in lung tissues were detected by ELISA. Hematoxylin-eosin stain was used to observe the morphological changes of lung tissues after burn. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assays were performed to detect apoptosis in lung tissues after burn. The expression of proteins related to the Toll-like receptor 4 (TLR4)/NF-κB signaling pathway in lung tissues after burn was analyzed by western blotting.
Our results showed that hUCMSC-Exos successfully decreased TNF-α, IL-1β, and IL-6 levels in rats after burn, and this reduction was reversed when the miR-451 expression in the hUCMSC-Exo group was inhibited. HUCMSC-Exo-derived miR-451 improves ALI via the TLR4/NF-κB pathway.
We demonstrated that exosomes derived from hUCMSCs mediate miR-451 to attenuate burn-induced ALI.
本研究旨在探讨人脐带间充质干细胞（hUCMSC）衍生的外泌体（hUCMSC-Exos）在调节烧伤诱导的急性肺损伤（ALI）中的分子机制。
本研究首先从 hUCMSCs 中分离出外泌体，并通过透射电子显微镜进行鉴定。Western blot 分析测定外泌体中 CD9 和 CD63 蛋白标志物的表达。qRT-PCR 测定 hUCMSC-Exos 中 miR-451 的表达。ELISA 检测肺组织和血清中 TNF-α、IL-1β 和 IL-6 的水平，以及肺组织中丙二醛、髓过氧化物酶、超氧化物歧化酶的水平。苏木精-伊红染色观察烧伤后肺组织的形态变化。末端脱氧核苷酸转移酶介导的 dUTP-生物素缺口末端标记法检测烧伤后肺组织的细胞凋亡。Western blot 分析烧伤后肺组织中 Toll 样受体 4（TLR4）/NF-κB 信号通路相关蛋白的表达。
我们的结果表明，hUCMSC-Exos 成功降低了烧伤后大鼠 TNF-α、IL-1β 和 IL-6 的水平，而当 hUCMSC-Exo 组 miR-451 的表达受到抑制时，这种降低作用被逆转。hUCMSC-Exo 衍生的 miR-451 通过 TLR4/NF-κB 通路改善 ALI。
我们证明了人脐带间充质干细胞衍生的外泌体通过介导 miR-451 来减轻烧伤诱导的 ALI。
