Progressive Chromatin Condensation and H3K9 Methylation Regulate the Differentiation of Embryonic and Hematopoietic Stem Cells.
Epigenetic regulation serves as the basis for stem cell differentiation into distinct cell types, but it is unclear how global epigenetic changes are regulated during this process. Here, we tested the hypothesis that global chromatin organization affects the lineage potential of stem cells and that manipulation of chromatin dynamics influences stem cell function. Using nuclease sensitivity assays, we found a progressive decrease in chromatin digestion among pluripotent embryonic stem cells (ESCs), multipotent hematopoietic stem cells (HSCs), and mature hematopoietic cells. Quantitative high-resolution microscopy revealed that ESCs contain significantly more euchromatin than HSCs, with a further reduction in mature cells. Increased cellular maturation also led to heterochromatin localization to the nuclear periphery. Functionally, prevention of heterochromatin formation by inhibition of the histone methyltransferase G9A resulted in delayed HSC differentiation. Our results demonstrate global chromatin rearrangements during stem cell differentiation and that heterochromatin formation by H3K9 methylation regulates HSC differentiation.
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Fernando
F
Ugarte
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Rebekah
R
Sousae
National Center for X-ray Tomography, UCSF, San Francisco, CA 94143, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Bertrand
B
Cinquin
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Eric W
EW
Martin
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Jana
J
Krietsch
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Gabriela
G
Sanchez
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Margaux
M
Inman
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Herman
H
Tsang
The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Medicine Department, Hem/Onc Division, University of California, San Francisco, San Francisco, CA 94143, USA.
Matthew
M
Warr
The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, Medicine Department, Hem/Onc Division, University of California, San Francisco, San Francisco, CA 94143, USA.
Emmanuelle
E
Passegué
National Center for X-ray Tomography, UCSF, San Francisco, CA 94143, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Carolyn A
CA
Larabell
Institute for the Biology of Stem Cells, Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA. Electronic address: cforsber@soe.ucsc.edu.
E Camilla
EC
Forsberg
D000818:Animals; D002454:Cell Differentiation; D042002:Chromatin Assembly and Disassembly; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006570:Heterochromatin / Q000235:genetics / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008745:Methylation; D051379:Mice; D008810:Mice, Inbred C57BL
D006570:Heterochromatin; D006657:Histones; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase