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

        从脓毒症患者血浆中分离出的外泌体可通过炎症反应和氧化应激等多种方式诱导血管内皮细胞凋亡及心肌抑制。尽管已有研究证实这些包含有遗传物质的囊泡与细胞间通信紧密相关，但其在脓毒症发病过程中的确切分子机制尚未阐明。本研究试图对和炎症反应相关的microRNAs (miRNAs)及信使RNAs (mRNAs)表达情况以及脓毒性休克患者外泌体的氧化还原代谢过程进行系统评价。

        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

        从24例脓毒性休克患者体内采集刚收住ICU及治疗7天后的血液标本。12名健康志愿者设为对照组。高速离心方法分离外泌体，利用qRT-PCR阵列方法对mRNA表达进行定量分析。

        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).

        结果

        与健康志愿者相比，脓毒症患者的外泌体在65个核外miRNAs中存在异常表达，其中28个miRNAs在刚入组时及7天后表达均明显异常(18个miRNAs表达上调，10个miRNAs表达下调)。在脓毒症组中，存活患者miRNAs表达又显著异于死亡患者。相比健康对照组而言，脓毒症患者组升高的miRNAs表达水平与其炎症反应剧烈程度平行。研究同时发现，体内miRNAs表达与细胞周期调节也密切相关。研究组中，与氧化还原代谢(髓过氧化物酶，64倍;过氧化还原酶3抗体，2.6倍;超氧化物歧化酶2，2.2倍)及氧化还原反应应答基因(叉头蛋白M1抗体, 21倍; SELS, 16倍;谷氧还蛋白2, 3.4倍)关系密切的mRNAs水平均明显升高，而这又与脓毒症发生有关。升高的髓过氧化物酶mRNA水平可一直持续到收住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.

        结论

        脓毒性休克患者体内分泌的外泌体可表达与其致病因素(包括炎症反应、氧化应激、细胞周期调节)相关的miRNAs和mRNAs。外泌体可能在在脓毒症细胞间通讯过程中扮演着全新的角色。