白介素-18及NOD样受体蛋白3炎性小体在痤疮发病中的作用研究

目的 探讨白介素-18 （IL-18）及NOD样受体蛋白3 （NLRP3）炎性小体在痤疮炎性发病机制中的作用。方法 以痤疮丙酸杆菌悬液〔感染复数（MOI）=0、10、20、30）〕刺激人角质形成细胞（NHEK） 12 h、24 h、36 h，ELISA法检测NHEK中IL-18蛋白的表达量，real-time PCR检测NHEK中IL-18 mRNA的表达。将NHEK细胞分为3组:特异性NLRP3小干扰RNA（siRNA）转染NHEK 36 h后，以MOI=30的痤疮丙酸杆菌悬液刺激NHEK 36 h（siRNA组）；不转染、不以菌液刺激的NHEK为空白对照组；不转染、只以MOI=30的痤疮丙酸杆菌悬液刺激36 h的NHEK为阳性对照组。ELISA法和real time-PCR法检测3组NHEK中IL-18蛋白和基因的表达量， Western blot法检测NLRP3炎性小体的表达情况。结果 NHEK经痤疮丙酸杆菌悬液刺激后IL-18蛋白和基因的表达量增加，具有时间相关性和剂量相关性（r均＞0.75， P<0.05) ，以菌悬液MOI=30、刺激36 h最为明显。siRNA组IL-18蛋白和基因表达量、NLRP3炎性小体的表达量较阳性对照组降低，但高于空白对照组，差异有统计学意义（ P<0.05）。结论 痤疮丙酸杆菌刺激NHEK分泌IL-18可能需要NLRP3炎性小体的参与。

IL-18 and NLRP3 in the Process of Acnevulgaris

Objective To determine the role of inlerleukin-18 (IL-18) and nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) in acne vulgaris. Methods We used propionibacterium acnes (P.acnes） suspensions 〔multiplicity of infection (MOI)=0,10,20,30〕 to stimulate normal human epidermal kerationocytes (NHEKs) for 12, 24, and 36 h, respectively. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the protein level of IL-18. Real-time quantitative PCR (real-time PCR) was adopted to detect the mRNA of IL-18.The NHEKs were divided into three groups: ① siRNA group: NHEKs were pretreated with siRNA for 36 h, followed by 36 h exposure to MOI=30 of P.ances suspensions; ② blank control group: NHEKs free from siRNA transfection and P.ances suspensions; ③ positive control group: NHEKs free from siRNA transfection were exposed to P.ances suspensions (MOI=30).The expression of NLRP3 was detected by Western blot. Results The expressions of protein and mRNA of IL-18 increased with exposure to P.ances suspensions in a dose responsive way (r＞0.75， P<0.05), with the peak effects showing for MOI=30 at 36 h. The expression of IL-18 decreased in the siRNA group compared with the positive control, but was still higher than that of the blank group( P<0.05). Conclusion P.ances stimulates NHEK cells to secrete IL-18. The process possibly requires the involvement of NLRP3.