The role of miR-29c/B7-H3/Th17 axis in children with Mycoplasma pneumoniae pneumonia
The role of miR-29c/B7-H3/Th17 axis in children with Mycoplasma pneumoniae pneumonia
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miR-29c/B7-H3/Th17轴在儿童肺炎支原体肺炎中的作用
DOI：
10.1186/s13052-019-0655-5
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发表时间：
2019-05-14
影响因子：
3.6
通讯作者：
Chen, Zheng-rong
中科院分区：
文献类型：
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作者：
Li, Qing-ling;Wu, Yin-yin;Chen, Zheng-rong
背景：肺炎支原体是儿童社区获得性肺炎最常见的病因之一。最近的研究表明，重症或致死性肺炎支原体的发病率逐渐增加，这可能与过度炎症有关。然而，肺炎支原体肺炎(MPP)过度炎症的确切发病机制尚不清楚。本研究旨在揭示miR-29c/B7-H3/Th17轴在MPP患儿中的作用。所有入选的儿童均经实时荧光定量聚合酶链式反应和酶联免疫吸附试验确诊为肺炎支原体感染。如果儿童与其他病原体同时感染，则被排除在外。共有52名MPP儿童和26名对照儿童入选。用实时荧光定量聚合酶链式反应(Real-time PCR)检测MPP患儿单核细胞MIR-29c的表达，用ELISA法检测可溶性B7-H3(SB7-H3)和IL-17的表达，并探讨其临床意义。通过miR-29c过表达、沉默技术和荧光素酶报告基因检测，确定B7-H3是否是miR-29c的直接靶点。结果：52例MPP患儿平均年龄77±33个月，其中男性23例，占44.2%。胸腔积液19例，占36.5%。MPP患儿miR-29c水平明显低于对照组(P<0.05)，SB7-H3和IL-17水平显著高于对照组(P均<0.05)。恢复期与急性期比较，miR-29c显著升高，SB7-H3和IL-17显著降低(P均<0.05)。MPP患儿急性期血清SB7-H3水平与IL-17水平呈正相关(r=0.361，P=0.009)。合并胸腔积液的MPP患儿血清SB7-H3水平显著高于无胸腔积液的患儿(9952.3±3065.3对7449.7±2231.5，pg/ml)，且与发热天数呈正相关。MiR-29c水平与肺炎支原体特异性Ig G、Ig M水平呈负相关。高浓度B7-H3(15μg/ml)可增强ROR-γt的表达，增加IL-17A的表达。基于荧光素酶报告基因分析和免疫荧光染色的功能研究表明，B7-H3是miR-29c的直接靶点，miR-29c的沉默或过度表达可上调或下调THP-1细胞中B7-H3的表达。结论：miR-29c/B7-H3/Th17轴在儿童MPP的过度炎症中起重要作用。MIR-29c和B7-H3可能成为防治MPP的新靶点，并可能成为判断预后的新的、有潜力的生物标志物。
Background:Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired pneumonia in children. Recent studies demonstrated that the incidence of severe or fatal M. pneumoniae was gradually increasing, which may be related to the excessive inflammation. However, the exact pathogenesis of excessive inflammation in Mycoplasma pneumoniae pneumonia(MPP) is still unclear. This study aimed to reveal the role of miR-29c/B7-H3/Th17 axis in children with MPP.Methods:Children hospitalized in Respiratory Department during Jan. 2014 to Dec. 2015 were enrolled. All children enrolled was confirmed with MP infection using real-time PCR and ELISA. Children were excluded if they were co-infected with other pathogens. A total of 52 children with MPP and 26 controls were enrolled. miR-29c expression in monocytes of children with MPP was determined by real-time PCR and soluble B7-H3 (sB7-H3) and IL-17 were determined by ELISA, and explore their clinical significance. miR-29c overexpression and silencing technology and luciferase reporter assay were performed to confirm whether B7-H3 is the direct target of miR-29c. The levels of transcription factor ROR-γt in CD4+ T cells and cytokine IL-17A in supernatant were detected after stimulated by different concentrations of B7-H3 fusion protein in vitro.Results:Of all 52 children with MPP, the mean age of the children were 77 ± 33 months, and 23 cases were male accounting for 44.2%. Nineteen cases had pleural effusion accounting for 36.5%. Children with MPP had significantly lower level of miR-29c and higher level of sB7-H3 and IL-17 compared to controls (both P < 0.05). The level of miR-29c significantly increased during convalescent phase compared to that of acute phase while sB7-H3 and IL-17 significantly decreased during convalescent phase (both P < 0.05). There was a positive correlation between the level of sB7-H3 and IL-17 in children with MPP during acute-stage (r = 0.361,P = 0.009). Children with MPP combined with pleural effusion had significantly higher level of sB7-H3 compared to those without pleural effusion (9952.3 ± 3065.3 vs. 7449.7 ± 2231.5, pg/ml), and the levels of sB7-H3 was positively correlated with the number of days of fever. The level of miR-29c was negatively correlated with M. pneumoniae specific IgG, IgM level. High concentrations of B7-H3(15μg/ml) could enhance ROR-γt expression and increase IL-17A. Functional studies based on luciferase reporter assay and immunofluorescence staining suggested that B7-H3 is the direct target of miR-29c, and miR-29c silencing or overexpression could up- or down-regulate the expression of B7-H3 in THP-1 cells.Conclusions:The axis of miR-29c/B7-H3/Th17 plays a vital role in children with MPP through excessive inflammation. miR-29c and B7-H3 may be the new target for the prevention and treatment of MPP, and may be the novel and potential biomarkers for the assessment of prognosis.