目的 分析外膜蛋白W (OmpW)在鲍曼不动杆菌临床株中的分布及其可能致病机制。方法：选取碳青霉烯类耐药鲍曼不动杆菌31株(耐药组)及敏感株30株(敏感组)作为研究对象,Western Blot方法检测OmpW蛋白的表达特征差异；OmpW重组蛋白与Hep-2人喉癌上皮细胞株体外共孵育,检测其对Hep-2细胞增殖能力的影响；采用JC-1染色技术观察OmpW蛋白对Hep-2细胞的促凋亡作用,并采用western blot方法检测细胞凋亡相关通路蛋白表达情况。结果： OmpW蛋白在耐药株中的表达率(100%)明显高于敏感株(63.33%)(χ2^=12.359,P=0.000<0.01)。JC-1染料染色法检测中,OmpW蛋白与Hep-2细胞作用后,其凋亡细胞明显增多。40μg/mL和80μg/mL OmpW蛋白作用于细胞,其增殖能力明显减弱(均P＜0.05)；孵育12小时及24小时后,80μg/mL ompW组细胞增殖能力明显减弱(均P＜0.05)；在OmpW蛋白作用下, Hep-2细胞bcl-2蛋白相对表达量明显降低(P＜0.05),但无明显时间及浓度依赖特征；而DR4、Fas Ligand、Anti-IGF 1及Caspase 8蛋白表达量无明显变化。结论：耐碳青霉烯类鲍曼不动杆菌临床株高表达OmpW蛋白。OmpW重组蛋白可显著抑制Hep-2细胞增殖并呈浓度依赖性,并促进Hep-2细胞凋亡,促凋亡机制可能主要通过抑制Bcl-2家族蛋白相关信号通路来实现。

Objective The distribution of outer membrane protein W (OmpW) in Acinetobacter baumannii and its possible pathogenic mechanism were analyzed. Methods: Thirty-one carbapenem-resistant Acinetobacter baumannii strains (drug-resistant group) and 30 susceptible strains (sensitive group) were selected as research subjects, and the expression characteristics of ompW protein were detected by Western blot.Hep-2 human laryngeal carcinoma cell line was co-incubated with OmpW recombinant protein in vitro to detect its effect on the proliferation of Hep-2 cells.JC-1 staining was used to observe the pro-apoptotic effect of OmpW protein on Hep-2 cells, and Western blot was used to detect the expression levels of apoptosis-related pathway proteins. Results: The expression rate of OmpW protein in resistant strain (100%) was significantly higher than that in sensitive strain (63.33%) (χ2=12.359, P=0.000 lt; 0.01). JC-1 staining showed that the apoptotic cells of Hep-2 cells increased significantly after the interaction of OmpW protein with HeP-2 cells. The proliferative ability of 40μg/mL and 80μg/mL OmpW was significantly decreased (all P < 0.05). After incubation for 12 h and 24 h, the proliferation ability of 80μg/mL ompW group was significantly decreased (all P < 0.05). The relative expression level of bcl-2 protein in Hep-2 cells was significantly decreased under the treatment of OmpW protein (P < 0.05), but there were no obvious time and concentration dependent characteristics. The expression levels of DR4, Fas Ligand, Anti-IGF 1 and Caspase 8 had no significant changes. Conclusion: OmpW protein was highly expressed in carbapenem-resistant Acinetobacter baumannii. OmpW inhibited Hep-2 cell proliferation in a concentration-dependent manner, and promoted apoptosis of Hep-2 cells. The apoptotic mechanism may be mainly achieved by inhibiting Bcl-2 family protein-related signaling pathways.

(No.2017MS0847)