GSK3β regulates physiological migration of stem/progenitor cells via cytoskeletal rearrangement

J Clin Invest. 2013 Apr;123(4):1705-17. doi: 10.1172/JCI64149. Epub 2013 Mar 8.

Abstract

Regulation of hematopoietic stem and progenitor cell (HSPC) steady-state egress from the bone marrow (BM) to the circulation is poorly understood. While glycogen synthase kinase-3β (GSK3β) is known to participate in HSPC proliferation, we revealed an unexpected role in the preferential regulation of CXCL12-induced migration and steady-state egress of murine HSPCs, including long-term repopulating HSCs, over mature leukocytes. HSPC egress, regulated by circadian rhythms of CXCL12 and CXCR4 levels, correlated with dynamic expression of GSK3β in the BM. Nevertheless, GSK3β signaling was CXCL12/CXCR4 independent, suggesting that synchronization of both pathways is required for HSPC motility. Chemotaxis of HSPCs expressing higher levels of GSK3β compared with mature cells was selectively enhanced by stem cell factor-induced activation of GSK3β. Moreover, HSPC motility was regulated by norepinephrine and insulin-like growth factor-1 (IGF-1), which increased or reduced, respectively, GSK3β expression in BM HSPCs and their subsequent egress. Mechanistically, GSK3β signaling promoted preferential HSPC migration by regulating actin rearrangement and microtubuli turnover, including CXCL12-induced actin polarization and polymerization. Our study identifies a previously unknown role for GSK3β in physiological HSPC motility, dictating an active, rather than a passive, nature for homeostatic egress from the BM reservoir to the blood circulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Animals
  • Cells, Cultured
  • Chemokine CXCL12 / physiology
  • Chemotaxis*
  • Enzyme Activation
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / metabolism
  • Glycogen Synthase Kinase 3 / physiology*
  • Glycogen Synthase Kinase 3 beta
  • Hematopoietic Stem Cells / enzymology
  • Hematopoietic Stem Cells / physiology*
  • Humans
  • Insulin-Like Growth Factor I / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred NOD
  • Mice, SCID
  • Microtubules / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Receptor, IGF Type 1 / metabolism
  • Receptors, CXCR4 / metabolism
  • Signal Transduction
  • Stem Cell Factor / physiology

Substances

  • CXCR4 protein, mouse
  • Chemokine CXCL12
  • Cxcl12 protein, mouse
  • Protein Kinase Inhibitors
  • Receptors, CXCR4
  • Stem Cell Factor
  • Insulin-Like Growth Factor I
  • Receptor, IGF Type 1
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta
  • Gsk3b protein, mouse
  • Glycogen Synthase Kinase 3