Comparative Study Of Induced Pluripotent Stem Cells Derived From Three Types Of Somatic Cells At The Transcriptome Level

Objective:Human somatic cells can be reprogrammed into pluripotent stem cells,and there are many sources of somatic cells in the reprogramming process,but the differences between human induced stem cells derived from various types of somatic cells at the molecular level and transcriptional regulatory level are still unclear.Here we established human induced stem cell lines derived from different somatic cells of an individual for the first time,and compared the differences between the established stem cells at the transcriptional level.The demonstration may be provide theoretical foundation in the stem cell therapy and clinical applications.Methods:We collected three types of human somatic cells from three individuals respectively.When received,the cells were separated and purificated.Then we transfected episomal vectors enconding several transcription factors into the human urine cells,the human dermal fibroblasts and the human blood cells through electroporation.And the transfected cells were cultured with culture medium.Human iPSC colonies were picked mechanically since the clones grew up,then we cultured and expanded the cells.Also we tested the validity and pluripotency of the expanding cells and established the human iPS cell lines derived from different somatic cells.After established the cell lines,we analyzed the transcriptome sequencing of cells by Paired-End sequencing methods based on Illumina technology.Then we analyzed the expression of differential genes and biological functions of those cells by bioinformatics and statistical methods to compare molecular mechanism actions between somatic cells during reprogramming process,This will provide theoretical basis for demaonstrating the molecular mechanism of reprogramming.Results:The electroporated somatic cells have similar morphology to ES in 10 to 15 days later,the expanding cells displayed normal karyotype,no-integrating exogenous genes and express pluripotent markers and genes.We also demonstrated the immune-deficient mice could generate teratomas and confirmed the cells have potential to differentiate into cell types of three germ layer in vivo.Thus we established the human induced pluripotent stem cell lines derived from different human somatic cells.We identified that there are no differences between iPSCs derived from different somatic cells at the transcriptome analysis level.The primary cell between the urine cells and the human dermal fibroblasts have no differences,but the blood cells have significant differences compared with the urine cells and the human dermal fibroblasts.Also,we demonstrated that the blood cellular reprogramming differ from the urine cellular reprogramming and the fibroblast cellular reprogramming.We further analysed the cell adhesion up regulated in the blood cellular reprogramming.Conclusion:We showed that human induced pluripotent stem cells genereted from different somatic cells by non-integrating plasmid-mediated transfection of transcription factors and established different human iPSC lines.The result proved that the generation of iPSC is not affected by the genetic background.In the same genetic background,the reprogramming process of the blood cell has significant differences compared with the reprogramming process of the urine cell and the fibroblast cell,including the cell adhesion up regulated after the blood cell reprogramming.So the study may provide theoretical foundations for choosing which kind of human iPSCs derived from different somatic cells in the future cell treatment,drug testing and tissue engineering for clinical apllications,and the research facilitating clinical applications of stem cells in the future.