Exosomes from patients with septic shock convey miRNAs related to inflammation and cell cycle regulation: new signaling pathways in sepsis?

Real JM,Ferreira LRP,Esteves GH,Koyama FC,Dias MVS,Bezerra-Neto JE,Cunha-Neto E,Machado FR,Salomão R,Azevedo LCP.

Critical Care, 2018, 22(1): 68.

doi: 10.1186/s13054-018-2003-3.

Original Research

Background

Exosomes isolated from plasma of patients with sepsis may induce vascular apoptosis and myocardial dysfunction by mechanisms related to inflammation and oxidative stress. Despite previous studies demonstrating that these vesicles contain genetic material related to cellular communication, their molecular cargo during sepsis is relatively unknown. In this study, we evaluated the presence of microRNAs (miRNAs) and messenger RNAs (mRNAs) related to inflammatory response and redox metabolism in exosomes of patients with septic shock.

背景

從膿毒症患者血漿中分離出的外泌體可通過炎症反應和氧化應激等多種方式誘導血管內皮細胞凋亡及心肌抑製。盡管已有研究證實這些包含有遺傳物質的囊泡與細胞間通信緊密相關，但其在膿毒症發病過程中的確切分子機製尚未闡明。本研究試圖對和炎症反應相關的microRNAs (miRNAs)及信使RNAs (mRNAs)表達情況以及膿毒性休克患者外泌體的氧化還原代謝過程進行係統評價。

Methods

Blood samples were collected from 24 patients with septic shock at ICU admission and after 7 days of treatment. Twelve healthy volunteers were used as control subjects. Exosomes were isolated by ultracentrifugation, and their miRNA and mRNA content was evaluated by qRT-PCR array.

方法

從24例膿毒性休克患者體內采集剛收住ICU及治療7天後的血液標本。12名健康誌願者設為對照組。高速離心方法分離外泌體，利用qRT-PCR陣列方法對mRNA表達進行定量分析。

Results

As compared with healthy volunteers, exosomes from patients with sepsis had significant changes in 65 exosomal miRNAs. Twenty-eight miRNAs were differentially expressed, both at enrollment and after 7 days, with similar kinetics (18 miRNAs upregulated and 10 downregulated). At enrollment, 35 differentially expressed miRNAs clustered patients with sepsis according to survival. The pathways enriched by the miRNAs of patients with sepsis compared with control subjects were related mostly to inflammatory response. The comparison of miRNAs from patients with sepsis according to hospital survival demonstrated pathways related mostly to cell cycle regulation. At enrollment, sepsis was associated with significant increases in the expression of mRNAs related to redox metabolism (myeloperoxidase, 64-fold; PRDX3, 2.6-fold; SOD2, 2.2-fold) and redox-responsive genes (FOXM1, 21-fold; SELS, 16-fold; GLRX2, 3.4-fold). The expression of myeloperoxidase mRNA remained elevated after 7 days (65-fold).

結果

與健康誌願者相比，膿毒症患者的外泌體在65個核外miRNAs中存在異常表達，其中28個miRNAs在剛入組時及7天後表達均明顯異常(18個miRNAs表達上調，10個miRNAs表達下調)。在膿毒症組中，存活患者miRNAs表達又顯著異於死亡患者。相比健康對照組而言，膿毒症患者組升高的miRNAs表達水平與其炎症反應劇烈程度平行。研究同時發現，體內miRNAs表達與細胞周期調節也密切相關。研究組中，與氧化還原代謝(髓過氧化物酶，64倍;過氧化還原酶3抗體，2.6倍;超氧化物歧化酶2，2.2倍)及氧化還原反應應答基因(叉頭蛋白M1抗體, 21倍; SELS, 16倍;穀氧還蛋白2, 3.4倍)關係密切的mRNAs水平均明顯升高，而這又與膿毒症發生有關。升高的髓過氧化物酶mRNA水平可一直持續到收住ICU第7天(65倍)。

Conclusions

Exosomes from patients with septic shock convey miRNAs and mRNAs related to pathogenic pathways, including inflammatory response, oxidative stress, and cell cycle regulation. Exosomes may represent a novel mechanism for intercellular communication during sepsis.

結論

膿毒性休克患者體內分泌的外泌體可表達與其致病因素(包括炎症反應、氧化應激、細胞周期調節)相關的miRNAs和mRNAs。外泌體可能在在膿毒症細胞間通訊過程中扮演著全新的角色。