Background: The HOX genes are master regulators of embryogenesis that are also involved inhematopoiesis. HOXA9 belongs to a cluster of HOX genes that play extensively studied roles inhematopoiesis and leukemogenesis.M...Background: The HOX genes are master regulators of embryogenesis that are also involved inhematopoiesis. HOXA9 belongs to a cluster of HOX genes that play extensively studied roles inhematopoiesis and leukemogenesis.Methods: We established HOXA9-inducible human embryonic stem cells (HOXA9/hESCs) with normalpluripotency and potential for hematopoiesis, which could be used to analyze gene function with highaccuracy. HOXA9/hESCs co-cultured with aorta–gonad–mesonephros-derived stromal cells (AGM-S3) wereinduced to overexpress HOXA9 with doxycycline (DOX) at various times after hematopoiesis started andthen subjected to flow cytometry.Results: Induction of HOXA9 from Day 4 (D4) or later notably promoted hematopoiesis and also increasedthe production of CD34+ cells and derived populations. The potential for myelogenesis was significantlyelevated while the potential for erythrogenesis was significantly reduced. At D14, a significant promotion ofS phase was observed in green fluorescent protein positive (GFP+) cells overexpressing HOXA9. NF-κBsignaling was also up-regulated at D14 following induction of HOXA9 on D4. All of these effects could becounteracted by addition of an NF-κB inhibitor or siRNA against NFKB1 along with DOX.Conclusions: Overexpression of HOXA9 starting at D4 or later during hematopoiesis significantly promotedhematopoiesis and the production of myeloid progenitors while reduced the production of erythroidprogenitors, indicating that HOXA9 plays a key role in hematopoiesis and differentiation of hematopoieticlineages.展开更多
基金This work was supported by awards from the CAMS Initiatives for Innovative Medicine(2016-I2M-1-018 to F.Ma and 2017-I2M-3-021 to J.X.Liu)Sichuan Provincial Science and Technology Department Key R&D projects(020YFSY0023 to B.Chen)the Chengdu Science and Technology Project-Technology Innovation R&D(2018-YF05-01341-SN to B.Chen).
文摘Background: The HOX genes are master regulators of embryogenesis that are also involved inhematopoiesis. HOXA9 belongs to a cluster of HOX genes that play extensively studied roles inhematopoiesis and leukemogenesis.Methods: We established HOXA9-inducible human embryonic stem cells (HOXA9/hESCs) with normalpluripotency and potential for hematopoiesis, which could be used to analyze gene function with highaccuracy. HOXA9/hESCs co-cultured with aorta–gonad–mesonephros-derived stromal cells (AGM-S3) wereinduced to overexpress HOXA9 with doxycycline (DOX) at various times after hematopoiesis started andthen subjected to flow cytometry.Results: Induction of HOXA9 from Day 4 (D4) or later notably promoted hematopoiesis and also increasedthe production of CD34+ cells and derived populations. The potential for myelogenesis was significantlyelevated while the potential for erythrogenesis was significantly reduced. At D14, a significant promotion ofS phase was observed in green fluorescent protein positive (GFP+) cells overexpressing HOXA9. NF-κBsignaling was also up-regulated at D14 following induction of HOXA9 on D4. All of these effects could becounteracted by addition of an NF-κB inhibitor or siRNA against NFKB1 along with DOX.Conclusions: Overexpression of HOXA9 starting at D4 or later during hematopoiesis significantly promotedhematopoiesis and the production of myeloid progenitors while reduced the production of erythroidprogenitors, indicating that HOXA9 plays a key role in hematopoiesis and differentiation of hematopoieticlineages.
