title: Influences of lamin A levels on induction of pluripotent stem cells.
abstract: Lamin A is an inner nuclear membrane protein that maintains nuclear structure integrity, is involved in transcription, DNA damage response and genomic stability, and also links to cell differentiation, senescence, premature aging and associated diseases. Induced pluripotent stem (iPS) cells have been successfully generated from various types of cells and used to model human diseases. It remains unclear whether levels of lamin A influence reprogramming of somatic cells to pluripotent states during iPS induction. Consistently, lamin A is expressed more in differentiated than in relatively undifferentiated somatic cells, and increases in expression levels with age. Somatic cells with various expression levels of lamin A differ in their dynamics and efficiency during iPS cell induction. Cells with higher levels of lamin A show slower reprogramming and decreased efficiency to iPS cells. Furthermore, depletion of lamin A by transient shRNA accelerates iPS cell induction from fibroblasts. Reduced levels of lamin A are associated with increased expression of pluripotent genes Oct4 and Nanog, and telomerase genes Tert and Terc. On the contrary, overexpression of lamin A retards somatic cell reprogramming to iPS-like colony formation. Our data suggest that levels of lamin A influence reprogramming of somatic cells to pluripotent stem cells and that artificial silencing of lamin A facilitates iPS cell induction. These findings may have implications in enhancing rejuvenation of senescent or older cells by iPS technology and manipulating lamin A levels.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Department of Genetics and Cell Biology, College of Life Sciences, Nankai University ,  Tianjin 300071 ,  China ; Tianjin-Oxford Joint Laboratory of Gene Therapy, Tianjin Research Centre of Basic Medical Science, Tianjin Medical University ,  Tianjin 300070 ,  China.
authors.forename: Bingfeng
authors.initials: B
authors.lastname: Zuo
authors.forename: Jiao
authors.initials: J
authors.lastname: Yang
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Yu
authors.initials: Y
authors.lastname: Yin
authors.forename: Jiameng
authors.initials: J
authors.lastname: Dan
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.forename: Lin
authors.initials: L
authors.lastname: Liu