Plasma microRNAs are promising novel biomarkers for the early detection of Toxoplasma gondii infection

Background: micrornas (mirnas) have been shown to be present in plasma,which are remarkably stable,and have been suggested as disease biomarkers. toxoplasma gondii (t. gondii) is a protozoan parasite that is infective to a wide range of animals and human beings. previous studies have found that the parasite generated a large number of mirnas during proliferation and it is known that the spectrum of mirna expression in the infected hosts is pathogen-specific. to date,there are no reports regarding the application of micrornas as biomarkers for the early detection of t. gondii infection. methods: in this study,we investigated the expression patterns of 414 murine mirnas and tested their expression levels in the plasma after t. gondii infection by real-time pcr,with an ultimate purpose of identifying infection-related mirnas. three mirnas in particular,exhibiting prominently elevated expressions,were further validated in a large number of infected mice. the toxoplasma infection-specific mirnas were confirmed by comparing their expression levels with those of mice infected with plasmodium berghei,p. yoelii,p. chabaudi,cryptosporidium parvum,mouse hepatitis virus,and staphylococcus aureus. results: among the 414 mirna candidates identified by a real-time pcr array,71 were found to be up-regulated in the plasma of t. gondii infected mice. three of those mirnas (mmu-mir-712-3p,mmu-mir-511-5p and mmu-mir-217-5p) were prominently expressed in mice infected by both the rh and me49 strains of t. gondii. additionally,the elevated expression of these mirnas was toxoplasma-specific. conclusions: the levels of the three mirnas,mmu-mir-712-3p,mmu-mir-511-5p and mmu-mir-217-5p mirnas,were found specifically up-regulated in plasma of mice after t. gondii infection. © 2014 jia et al.; licensee biomed central ltd.