Altered Expression Of MicroRNAs In The Physiological Electric Fields Directed Migration Of Stem Cells

BACKGROUND:Stem cells have the ability to carry on multi-lineage differentiation, also defined as pluripotency which are widely used in clinical therapy. But poor directed migration ability to target tissues has been encountered in the clinical application of stem cells. The existence of bioelectricity was confirmed by the frog leg experiment. Studies reported endogenous electric fields play an important role in the embryonic development and the process of tissue damage repair, and exogenous electric field can guide directional migration of a series of cells. Cell electrotaxis may be related to Ca2+, EGF receptor and golgi apparatus polarization and so on. Subsequent research found the first pair of genes related to electrotaxis, PI3Kyand PTEN. MicroRNAs is a kind of small RNAs with about 22 nt length which is highly conservative and single non-coding, widespread in a variety of organisms, and playing a role in the process of growth, cell activity and so on.AIMS:This study intends to explore the effects of hESC migration in DC EF, screen out microRNAs related to electrotaxis, predict target genes and analyze functions and signal ways by bioinformatics.METHODS:hESC in 50mV/mm,150mV/mm and 250mV/mm for 6h respectively was tracked by ImageJ software. Differentially expressed microRNAs are screened by microRNA chip (KangChen Bio-tech) which are tested by qRT-PCR. Target genes are predicted by Microcosm, Miranda and Targetscan prediction which are tested byqRT-PCR. Function and pathways prediction are performed by GO analysis and KEGG respectively.RESULTS:Under this experimental condition, DC EF can guide hESC migrate to anode and increase the migration speed.413 microRNAs were tested and expressions of 4 microRNAs were up-regulated by microRNA array. Expressions of hsa-miR-4321 and hsa-miR-920 were up-regulate by more than 3 times after electric stimulus (150 mv/mm, 6 hours) and qRT-PCR showed that expressions of hsa-miR-4321 and hsa-miR-920 were up-regulate by more than 1.5 times. In addition, the target gene prediction show target genes of hsa-miR-4321 are VCL and ITGAM and target genes of Hsa-miR-920 are GIMAP5, STIM1 and KCNMB1. Function analysis showed that hsa-miR-4321 may be associated with cell adhesion and hsa-miR-920 may be associated with regulation of calcium ion channel. KEGG analysis showed that adherens junction may be involved in cellular electrotaxis.Conclusions:Under current experiment conditions, DC EFs could guide cultured hESCs migrate direct’ onally toward the anode. Expressions of hsa-miR-4321 and hsa-miR-920 were up-regulate. Bioinformatics analysis showed that hsa-miR-4321 and hsa-miR-920 respectively were related to cell adhesion and calcium ion channel regulation. EFs may guide directional migration of hESCs by target genes of hsa-miR-920-GIMAP5 and STIM1 and signal pathway of hsa-miR-4321-Adherens Junction.