title: JNK/SAPK Signaling Is Essential for Efficient Reprogramming of Human Fibroblasts to Induced Pluripotent Stem Cells.
abstract: Reprogramming of somatic cells to the phenotypic state termed "induced pluripotency" is thought to occur through three consecutive stages: initiation, maturation, and stabilisation. The initiation phase is stochastic but nevertheless very important as it sets the gene expression pattern that permits completion of reprogramming; hence a better understanding of this phase and how this is regulated may provide the molecular cues for improving the reprogramming process. c-Jun N-terminal kinase (JNK)/stress-activated protein kinase (SAPKs) are stress activated MAPK kinases that play an essential role in several processes known to be important for successful completion of the initiation phase such as cellular proliferation, mesenchymal to epithelial transition (MET) and cell cycle regulation. In view of this, we postulated that manipulation of this pathway would have significant impacts on reprogramming of human fibroblasts to induced pluripotent stem cells. Accordingly, we found that key components of the JNK/SAPK signaling pathway increase expression as early as day 3 of the reprogramming process and continue to rise in reprogrammed cells throughout the initiation and maturation stages. Using both chemical inhibitors and RNA interference of MKK4, MKK7 and JNK1, we tested the role of JNK/SAPK signaling during the initiation stage of neonatal and adult fibroblast reprogramming. These resulted in complete abrogation of fully reprogrammed colonies and the emergence of partially reprogrammed colonies which disaggregated and were lost from culture during the maturation stage. Inhibition of JNK/SAPK signaling resulted in reduced cell proliferation, disruption of MET and loss of the pluripotent phenotype, which either singly or in combination prevented establishment of pluripotent colonies. Together these data provide new evidence for an indispensable role for JNK/SAPK signaling to overcome the well-established molecular barriers in human somatic cell induced reprogramming. Stem Cells 2016;34:1198-1212.
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Irina
authors: I
authors: Neganova
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Evgenija
authors: E
authors: Shmeleva
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Jennifer
authors: J
authors: Munkley
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Valeria
authors: V
authors: Chichagova
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: George
authors: G
authors: Anyfantis
authors: Institute for Ageing and Health, Newcastle University.
authors: Rhys
authors: R
authors: Anderson
authors: Institute for Ageing and Health, Newcastle University.
authors: Joao
authors: J
authors: Passos
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: David J
authors: DJ
authors: Elliott
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Lyle
authors: L
authors: Armstrong
authors: Institute of Genetic Medicine, International Centre for Life and Centre for Integrated Systems Biology of Ageing and Nutrition.
authors: Majlinda
authors: M
authors: Lako
mesh_terms: D000328:Adult; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D065150:Cellular Reprogramming / Q000187:drug effects; D003114:Colony-Forming Units Assay; D015536:Down-Regulation / Q000187:drug effects; D004789:Enzyme Activation / Q000187:drug effects; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D007231:Infant, Newborn; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D008648:Mesoderm / Q000166:cytology; D008954:Models, Biological; D047428:Protein Kinase Inhibitors / Q000494:pharmacology
chemical_list: D047428:Protein Kinase Inhibitors; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4
keywords: JNKs; MKK4; MKK7; SAPK; hESC; hiPSC