title: Fetal stromal niches enhance human embryonic stem cell-derived hematopoietic differentiation and globin switch.
abstract: Hematopoiesis during mammalian embryonic development has been perceived as a migratory phenomenon, from the yolk sac blood island to the aorta-gonad-mesonephros (AGM) region, fetal liver (FL), and subsequently, the fetal bone marrow. In this study, we investigated the effects of primary stromal cells from fetal hematopoietic niches and their conditioned media (CM), applied singly or in sequential orders, on induction of human embryonic stem cells, H1, H9, and H14 lines, to hematopoietic cells. Our results demonstrated that stromal support of FL, AGM + FL, and AGM + FL + fetal bone marrow significantly increased the proliferation of embryoid bodies (EB) at day 18 of hematopoietic induction in the presence of thrombopoietin, stem cell factor, and Flt-3 ligand. AGM + FL also increased hematopoietic colony-forming unit (CFU) formation. CM did not enhance EB proliferation but CM of FL and AGM + FL significantly increased the density of total CFU and early erythroid (burst-forming unit) progenitors. Increased commitment to the hematopoietic lineage was demonstrated by enhanced expressions of CD45, alpha-, beta-, and gamma-globins in CFU at day 32, compared with EB at day 18. CM of FL significantly increased these globin expressions, indicating enhanced switches from embryonic to fetal and adult erythropoiesis. Over 50% and 10% of cells derived from CFU expressed CD45 and beta-globin proteins, respectively. Expressions of hematopoietic regulatory genes (Bmi-1, β-Catenin, Hox B4, GATA-1) were increased in EB or CFU cultures supported by FL or sequential CM. Our study has provided a strategy for derivation of hematopoietic cells from embryonic stem cells under the influence of primary hematopoietic niches and CM, particularly the FL.
authors: Department of Pediatrics, The Chinese University of Hong Kong , Shatin, Hong Kong.
authors: King Yiu
authors: KY
authors: Lee
authors: Benny Shu Pan
authors: BS
authors: Fong
authors: Kam Sze
authors: KS
authors: Tsang
authors: Tze Kin
authors: TK
authors: Lau
authors: Pak Cheung
authors: PC
authors: Ng
authors: Audrey Carmen
authors: AC
authors: Lam
authors: Kathy Yuen Yee
authors: KY
authors: Chan
authors: Chi Chiu
authors: CC
authors: Wang
authors: Hsiang Fu
authors: HF
authors: Kung
authors: Chi Kong
authors: CK
authors: Li
authors: Karen
authors: K
authors: Li
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D003114:Colony-Forming Units Assay; D017077:Culture Media, Conditioned / Q000494:pharmacology; D058732:Embryoid Bodies / Q000166:cytology / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005333:Fetus / Q000166:cytology*; D005786:Gene Expression Regulation / Q000187:drug effects; D005914:Globins / Q000235:genetics* / Q000378:metabolism; D006410:Hematopoiesis / Q000187:drug effects / Q000235:genetics; D006801:Humans; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000378:metabolism; D051379:Mice; D055153:Stem Cell Niche / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D055544:beta-Globins / Q000235:genetics / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D055544:beta-Globins; D005914:Globins; D017493:Leukocyte Common Antigens