Effect of Escherichia Coli Infection on Semen Sample Exosomes

Background and aim: exosomes are 40-150 nm in diameters. these vesicles are secreted by almost every cell in body. they have variety of sources and cargo molecules like proteins, lipids and genetic materials include mirnas. exosomes have been tracked in different body fluid like: serum, urine, milk, saliva and semen. it seems that seminal exosome can be utilized as an exceptional tool for diagnosis of male genital track disease and in the next step they are going to be used as a therapeutic agent. there are a lot of studies that focused on effects of bacterial infections on extracellular vesicles. this study focused on effect of escherichia coli infection on the seminal extracted exosomes. considering the importance of mirna in gene regulation and biological processes of the cell we examine the presence of mir-21 in seminal exosomes. methods: semen samples were collected from men referred to ivf clinic of gandhi hospital. each sample was equally divided to experimental and control groups. in experimental group semen sample was co-incubated with escherichia coli (1.5 * 108 cell in 1 ml of htf medium/ 1 ml of semen) for 3 hours. control group was semen sample incubated with htf without escherichia coli. exosomes were extracted from samples using ultracentrifugation at 100000 g for 1 h at 40c. exosomes were examined using scanning electron microscopy (sem) and dynamic light scattering (dls) and also flow cytometry. the expression of mir-21 and fas l, caspase 8, 5s rrna was assessed in different samples by real-time pcr. results: the initial characterization of extracted exosomes using dls showed average size and intercept, pdi 148.6 nm and 0.944, 0.261 respectively. also in flow cytometry exosomes were tracked by two markers cd63 and cd81. expression analysis showed different levels of apoptotic factors and mir-21 in different samples. conclusion: it seems that semen sample is a rich source of extracellular vesicles, especially exosomes and e.coli could increase expression of apoptotic factors such as: fas l, caspase 8 and mir-21 in seminal exosomes.