胰岛素对胞内不同水平环二鸟苷酸铜绿假单胞菌运动能力的影响

Effect of insulin on the motility of Pseudomonas aeruginosa strains with different levels of Cyclic diguanosine-5'-monophosphate in cells

目的探讨胰岛素对胞内环二鸟苷酸(Cyclic diguanosine-5'-monophosphate,c-di-GMP)浓度表达不同的铜绿假单胞菌(Pseudomonas aeruginosa,PA)运动能力的影响,为进一步研究胰岛素对胞内c-di-GMP浓度表达不同的PA在糖尿病小鼠模型中的作用提供基础。方法按胞内c-di-GMP表达量不同分为对照野生PAO1组、胞内c-di-GMP低表达PAO1/Plac-yhjH组和胞内c-di-GMP过表达PAO1/ΔwspF组。将三种菌株接种于无胰岛素的琼脂中,测定运动环直径以评估不同菌株的泳动、群集和蹭动能力。然后再将三种菌株接种于分别含有200nU/ml、200μU/ml和200mU/ml浓度胰岛素的琼脂中,分析不同菌株在胰岛素干预后其运动能力的变化。结果在无胰岛素干预下,与PAO1组相比,PAO1/ΔwspF组运动能力明显被抑制,相反PAO1/Plac-yhjH组的运动能力则稍提高。在PAO1、PAO1/Plac-yhjH菌株中,与热变性胰岛素对照组相比,含有200mU/ml、200μU/ml、200nU/ml三种胰岛素浓度组的泳动、群集运动直径都明显变小,差异具有统计学意义(P<0.05),且在三个浓度之间菌株的泳动、群集能力无统计学差异,其影响与胰岛素无剂量依赖性。结论胰岛素能抑制PA野生菌株及细胞内c-di-GMP低表达菌株的泳动、群集能力,且与胰岛素无剂量依赖性。

Objective To investigate the impact of insulin on the motility of Pseudomonas aeruginosa (PA) with different c-di-GMP concentrations, so as to provide a basis for further study on the effect of insulin on PA with different c-di-GMP concentrations in diabetic mice. Methods According to the intracellular c-di-GMP expression, the high intracellular c-di-GMP content PAO1/ΔwspF group, low c-di-GMP content PAO1/Plac-yhjH group and the control wild strain were selected. The insulin-free agar was first inoculated, and the shape and trajectory of the bacterial movement centered on the inoculation point were observed, and the diameter of the exercise ring was measured to evaluate the motility of PA in the cells with different c-di-GMP concentrations. Then the three kinds of strains were inoculated into AGAR containing insulin concentrations of 200nU/ml, 200μU/ml and 200mU/ml, respectively, observed the changes in the motility of different strains after insulin intervention. Results In the absence of insulin intervention, compared with the PAO1 group, the motility of the PAO1/ΔwspF group was significantly inhibited, whereas the motility of the PAO1/PlacyhjH group slightly increased. Under the intervention of insulin, the swimming and swarming ability of PAO1/Plac-yhjH group and PAO1 group were significantly inhibited, and no correlation with insulin concentration gradient, but had no effect on the inhibition of motility of PAO1/ΔwspF group. Conclusion Insulin can inhibit the swimming and swarming ability of PAO1/Plac-yhjH strain and PAO1 strain,which is not dose-dependent with insulin.