title: Argonaute-2-null embryonic stem cells are retarded in self-renewal and differentiation.
abstract: RNA interference (RNAi) pathways regulate self-renewal and differentiation of embryonic stem (ES) cells. Argonaute 2 (Ago2) is a vital component of RNA-induced silencing complex (RISC) and the only Ago protein with slicer activity. We generated Ago2-deficient ES cells by conditional gene targeting. Ago2-deficient ES cells are defective in the small-RNA-mediated gene silencing and are significantly compromised in biogenesis of mature microRNA. The self-renewal rate of Ago2-deficient ES cells is affected due to failure of silencing of Cdkn1a by EScell- specific microRNAs (miRNA) in the absence of Ago2. Interestingly, unlike Dicer- and Dgcr8-deficient ES cells, they differentiate to all three germ layers both in vivo and in vitro. However, early differentiation of Ago2-deficient ES cells is delayed by 2-4 days as indicated by persistence of higher levels of self-renewal/ pluripotency markers during differentiation. Further, appearance of morphological and differentiation markers is also delayed during the differentiation. In this study we show that Ago2 is essential for normal self-renewal and differentiation. Also, our data suggest that self-renewal and differentiation of ES cells are regulated by both siRNA and miRNA pathways.
authors.affiliation: Centre for Cellular and Molecular Biology, CSIR, Hyderabad 500007, India.
authors.forename: P Chandra
authors.initials: PC
authors.lastname: Shekar
authors.forename: Adnan
authors.initials: A
authors.lastname: Naim
authors.forename: D Partha
authors.initials: DP
authors.lastname: Sarathi
authors.forename: Satish
authors.initials: S
authors.lastname: Kumar
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000235:genetics* / Q000378:metabolism; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D047108:Embryonic Development / Q000235:genetics*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D018390:Gene Targeting; D017930:Genes, Reporter; D005855:Germ Layers / Q000166:cytology / Q000378:metabolism; D008156:Luciferases / Q000032:analysis; D051379:Mice; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics
chemical_list: D060565:Argonaute Proteins; D015415:Biomarkers; C540084:Ciz1 protein, mouse; D035683:MicroRNAs; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; D008156:Luciferases