biostudies-literatureWang PChinese Academy of SciencesNational Natural Science Foundation of China5903-5913https://www.ebi.ac.uk/biostudies/studies/S-EPMC6463920biostudies-literatureUnknown33(5)Exposure to spaceflight and microgravity causes physiologic and psychologic changes including bone loss, cardiovascular dysfunction, and immune dysfunction. Anemia and hematopoietic disorders are observed in astronauts after spaceflight. Hematopoietic stem and progenitor cells (HSPCs), which can self-renew and give rise to all blood cells, play vital roles in hematopoiesis and homeostasis; however, the molecular mechanisms responsible for the impacts of microgravity on the proliferation of HSPCs remain unclear. We maintained mouse bone marrow HSPCs in the presence of stem cell factor for 12 d under spaceflight and simulated microgravity conditions, respectively, and analyzed cell proliferation and gene expression. Both spaceflight and simulated microgravity significantly decreased the numbFASEB journal : official publication of the Federation of American Societies for Experimental BiologySpaceflight/microgravity inhibits the proliferation of hematopoietic stem cells by decreasing Kit-Ras/cAMP-CREB pathway networks as evidenced by RNA-Seq assays.PMC64639203147086081530049XDA16030301U1738111Qian JShi LWang PZhang JTian HLi LZhao YfalseSpaceflight/microgravity inhibits the proliferation of hematopoietic stem cells by decreasing Kit-Ras/cAMP-CREB pathway networks as evidenced by RNA-Seq assays.Exposure to spaceflight and microgravity causes physiologic and psychologic changes including bone loss, cardiovascular dysfunction, and immune dysfunction. Anemia and hematopoietic disorders are observed in astronauts after spaceflight. Hematopoietic stem and progenitor cells (HSPCs), which can self-renew and give rise to all blood cells, play vital roles in hematopoiesis and homeostasis; however, the molecular mechanisms responsible for the impacts of microgravity on the proliferation of HSPCs remain unclear. We maintained mouse bone marrow HSPCs in the presence of stem cell factor for 12 d under spaceflight and simulated microgravity conditions, respectively, and analyzed cell proliferation and gene expression. Both spaceflight and simulated microgravity significantly decreased the numb2019-01-01T00:00:00Z2019 May2026-04-30T07:33:53.486Z2026-04-07T15:53:35.049ZS-EPMC64639203072162710.1096/fj.201802413R10.1096/fj.201802413r