title: Inhibition of aldehyde dehydrogenase and retinoid signaling induces the expansion of human hematopoietic stem cells.
abstract: Aldehyde dehydrogenase (ALDH) is an enzyme that is expressed in the liver and is required for the conversion of retinol (vitamin A) to retinoic acids. ALDH is also highly enriched in hematopoietic stem cells (HSCs) and is considered a selectable marker of human HSCs, although its contribution to stem cell fate remains unknown. In this study, we demonstrate that ALDH is a key regulator of HSC differentiation. Inhibition of ALDH with diethylaminobenzaldehyde (DEAB) delayed the differentiation of human HSCs that otherwise occurred in response to cytokines. Moreover, short-term culture with DEAB caused a 3.4-fold expansion in the most primitive assayable human cells, the nonobese diabetic/severe combined immunodeficiency mouse repopulating cells, compared with day 0 CD34(+)CD38(-)lin(-) cells. The effects of DEAB on HSC differentiation could be reversed by the coadministration of the retinoic acid receptor agonist, all-trans-retinoic acid, suggesting that the ability of ALDH to generate retinoic acids is important in determining HSC fate. DEAB treatment also caused a decrease in retinoic acid receptor-mediated signaling within human HSCs, suggesting directly that inhibition of ALDH promotes HSC self-renewal via reduction of retinoic acid activity. Modulation of ALDH activity and retinoid signaling is a previously unrecognized and effective strategy to amplify human HSCs.
authors.affiliation: Division of Cellular Therapy, Duke University Medical Center, Durham, NC 27710, USA. john.chute@duke.edu
authors.forename: John P
authors.initials: JP
authors.lastname: Chute
authors.forename: Garrett G
authors.initials: GG
authors.lastname: Muramoto
authors.forename: John
authors.initials: J
authors.lastname: Whitesides
authors.forename: Michael
authors.initials: M
authors.lastname: Colvin
authors.forename: Rachid
authors.initials: R
authors.lastname: Safi
authors.forename: Nelson J
authors.initials: NJ
authors.lastname: Chao
authors.forename: Donald P
authors.initials: DP
authors.lastname: McDonnell
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000080924:Aldehyde Dehydrogenase 1 Family; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051379:Mice; D016513:Mice, SCID; D050697:Retinal Dehydrogenase; D012176:Retinoids / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D010128:p-Aminoazobenzene / Q000031:analogs & derivatives
chemical_list: D015703:Antigens, CD; C090460:HOXB4 protein, human; D018398:Homeodomain Proteins; C513262:Hoxb4 protein, mouse; D007527:Isoenzymes; D012176:Retinoids; D014157:Transcription Factors; C007368:C.I. Solvent Yellow 56; D010128:p-Aminoazobenzene; D000080924:Aldehyde Dehydrogenase 1 Family; D000444:Aldehyde Dehydrogenase; C510223:ALDH1A1 protein, human; C515028:ALDH1A1 protein, mouse; D050697:Retinal Dehydrogenase