title: Autophagy in human embryonic stem cells.
abstract: Autophagy (macroautophagy) is a degradative process that involves the sequestration of cytosolic material including organelles into double membrane vesicles termed autophagosomes for delivery to the lysosome. Autophagy is essential for preimplantation development of mouse embryos and cavitation of embryoid bodies. The precise roles of autophagy during early human embryonic development, remain however largely uncharacterized. Since human embryonic stem cells constitute a unique model system to study early human embryogenesis we investigated the occurrence of autophagy in human embryonic stem cells. We have, using lentiviral transduction, established multiple human embryonic stem cell lines that stably express GFP-LC3, a fluorescent marker for the autophagosome. Each cell line displays both a normal karyotype and pluripotency as indicated by the presence of cell types representative of the three germlayers in derived teratomas. GFP expression and labelling of autophagosomes is retained after differentiation. Baseline levels of autophagy detected in cultured undifferentiated hESC were increased or decreased in the presence of rapamycin and wortmannin, respectively. Interestingly, autophagy was upregulated in hESCs induced to undergo differentiation by treatment with type I TGF-beta receptor inhibitor SB431542 or removal of MEF secreted maintenance factors. In conclusion we have established hESCs capable of reporting macroautophagy and identify a novel link between autophagy and early differentiation events in hESC.
authors: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia.
authors: Thien
authors: T
authors: Tra
authors: Lan
authors: L
authors: Gong
authors: Lin-Pin
authors: LP
authors: Kao
authors: Xue-Lei
authors: XL
authors: Li
authors: Catarina
authors: C
authors: Grandela
authors: Rodney J
authors: RJ
authors: Devenish
authors: Ernst
authors: E
authors: Wolvetang
authors: Mark
authors: M
authors: Prescott
mesh_terms: D000818:Animals; D001343:Autophagy; D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D011993:Recombinant Fusion Proteins