甲硝唑诱导阴道毛滴虫凋亡样细胞死亡

目的凋亡或程序性细胞死亡在多细胞生物体中已经被广泛研究,然而,关于单细胞寄生性原生动物细胞凋亡发生的分子机制却知之甚少。本研究旨在了解甲硝唑诱导阴道毛滴虫细胞凋亡的特征。方法培养阴道毛滴虫并用不同浓度的甲硝唑进行处理。在不同的时间间隔进行活细胞计数。提取甲硝唑处理过的阴道毛滴虫基因组进行DNA断裂片段检测。用DNA断端末端标记(TUNEL)法测定甲硝唑处理后阴道毛滴虫核酸内切酶活性。流式细胞检测分析脂酰丝氨酸暴露情况。结果甲硝唑可以诱导阴道毛滴虫出现凋亡样细胞死亡。这种凋亡样细胞死亡表现为细胞皱缩,磷脂酰丝氨酸暴露以及核染色体凝聚,但并未检测到寡核苷酸DNA梯带。结论阴道毛滴虫程序性细胞死亡的调节通路不同于多细胞生物体。确定导致原生动物细胞死亡的凋亡通路也许最终可用于鉴定新的治疗靶点。

Induction of Apoptotic-like Cell Death in Trichomonas vaginalis by Metronidazole

Objective Apoptosis or programmed cell death(PCD)has been studied extensively in multicellular organisms,however,very little is known about the molecular mechanisms by which apoptosis occurs in unicellular protozoan parasites.The aim of this study is to characterize the apoptosis or PCD of Trichomonas vaginalis induced by metronidazole(MTZ).Methods T.vaginalis strain cultures were treated with various concentrations of MTZ and the number of viable cells were determined at different time intervals.The genomic DNA of MTZ treated T.vaginalis was extracted and DNA fragmentation was analyzed.TUNEL assay was carried out to detect the endonuclease activity in T.vaginalis after MTZ treatment.Flow cytometric analysis was used to analyse the phosphatidylserine(PS)exposure of T.vaginalis.Results Metronidazole(MTZ)induced an apoptotic-like cell death in T.vaginalis.This apoptotic-like cell death was demonstrated by cell shrinkage,phosphatidylserine exposure,and nuclear chromatin condensation.However,no oligonucleosmal DNA laddering was detected.Conclusion The regulatory pathway of apoptotic cell death in T.vaginalis may be different from multicellular organisms.The determination of protozoan apoptotic pathways leading to cell death might ultimately allow the identification of new therapeutic targets.