[Abstract]
Acute lung injury (ALI) is the leading cause of death in sepsis patients. Exosomes participate in the occurrence and development of ALI by regulating endothelial cell inflammatory response, oxidative stress, and apoptosis, causing serious pulmonary vascular leakage and interstitial edema. The current study investigated the effect of exosomal miRNAs on endothelial cells during sepsis. We found a significant increase of miR-1-3p expression in CLP rats exosomes sequencing and sepsis patients』 exosomes, and LPS stimulated HUVEC in vitro. However, the specific biological function of miR-1-3p in ALI remains unknown. Therefore, mimics or inhibitors of miR-1-3p were transfected to modulate its expression in HUVEC. Cell proliferation, apoptosis, contraction, permeability, and membrane injury were examined via CCK-8, flow cytometry, phalloidin staining, Trans well assay, LDH activity, and Western blotting. The miR-1-3p target gene was predicted with miRNAs related databases and validated by luciferase reporter. Target gene expression was blocked by siRNA to explore the underlying mechanisms. The results illustrated increased miR-1-3p and decreased SERP1 expression both in vivo and vitro. SERP1 was a direct target gene of miR-1-3p. Upregulated miR-1-3p inhibits cell proliferation, promotes apoptosis and cytoskeleton contraction, increases monolayer endothelial cell permeability, and membrane injury by targeting SERP1, which leads to dysfunction of endothelial cells and weakens vascular barrier function involved in the development of ALI. MiR-1-3p and SERP1 may be promising therapeutic candidates for sepsis-induced lung injury.
【中文摘要】
急性肺損傷（ALI）是膿毒症患者死亡的主要原因之一。循環外泌體可通過其內容物介導細胞間通訊參與膿毒症ALI的發生發展。本研究發現盲腸結紮穿孔（CLP）大鼠和膿毒症患者血漿外泌體中miR-1-3p表達顯著增加，同時在CLP大鼠肺組織和膿毒症血漿外泌體處理的血管內皮細胞中高表達。體外研究發現miR-1-3p通過其靶基因內質網應激蛋白（SERP1）抑制血管內皮細胞增殖，促進其凋亡和細胞骨架收縮，增加單層內皮細胞通透性和細胞膜損傷。miR-1-3p拮抗劑可上調CLP大鼠肺組織中SERP1表達，減輕CLP大鼠肺水腫程度；體外過表達SERP1亦可改善miR-1-3p對血管內皮細胞的損傷。研究表明：膿毒症時，循環血漿外泌體miR-1-3p表達升高，可被肺組織內血管內皮細胞攝取並通過其靶基因SERP1介導內皮細胞功能障礙，削弱其屏障作用，參與膿毒症肺損傷的進展過程。因此miR-1-3p和SERP1可能為膿毒症肺損傷提供新的幹預靶點。