{"title":"An old player, the right niche.","authors":"Cheng Cheng Zhang","doi":"10.1097/BS9.0000000000000105","DOIUrl":null,"url":null,"abstract":"The cellular and molecular components of the niche for hematopoietic stem cells (HSCs) are still not well de fi ned. Angiopoietin-like proteins (Angptls) are a group of secreted glycoproteins that have been reported to play various roles, including the regulation of HSC activity. 1 Speci fi cally, Angptl2, a member of the Angptl family, was demonstrated to support HSC stemness through binding to inhibitory receptors. 2 Angptl2 has also been shown to support HSC activity in exosomes. 3 However, whether and how Angptl2 regulates HSC activities in the HSC niche were still unknown. Yu et al used an elegant approach to study these questions. 1 Based on the expression pattern of Angptl2 in bone marrow, several conditional knockout (KO) mice were generated to deplete Angptl2 from endothelial, mesenchymal stromal cells, megakaryocytes, and HSCs. Using a number of functional assays, including reconstitution analysis, fl ow cytometry, and immuno fl uorescence microscopy, the authors discovered that only endothelial cell-derived Angptl2 but not Angptl2 from other niche cell types supported the repopulation capacity, quiescent status, and niche localization of HSCs. They further demonstrated that Angptl2 enhances peroxisome-proliferator-activated receptor D expression to transactivate G0s2 and sustain the perinuclear localization of nucleolin that prevents HSCs from entering the cell cycle. study HSCs","PeriodicalId":67343,"journal":{"name":"血液科学(英文)","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/e3/fd/bls-4-99.PMC9354721.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"血液科学(英文)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1097/BS9.0000000000000105","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"HEMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The cellular and molecular components of the niche for hematopoietic stem cells (HSCs) are still not well de fi ned. Angiopoietin-like proteins (Angptls) are a group of secreted glycoproteins that have been reported to play various roles, including the regulation of HSC activity. 1 Speci fi cally, Angptl2, a member of the Angptl family, was demonstrated to support HSC stemness through binding to inhibitory receptors. 2 Angptl2 has also been shown to support HSC activity in exosomes. 3 However, whether and how Angptl2 regulates HSC activities in the HSC niche were still unknown. Yu et al used an elegant approach to study these questions. 1 Based on the expression pattern of Angptl2 in bone marrow, several conditional knockout (KO) mice were generated to deplete Angptl2 from endothelial, mesenchymal stromal cells, megakaryocytes, and HSCs. Using a number of functional assays, including reconstitution analysis, fl ow cytometry, and immuno fl uorescence microscopy, the authors discovered that only endothelial cell-derived Angptl2 but not Angptl2 from other niche cell types supported the repopulation capacity, quiescent status, and niche localization of HSCs. They further demonstrated that Angptl2 enhances peroxisome-proliferator-activated receptor D expression to transactivate G0s2 and sustain the perinuclear localization of nucleolin that prevents HSCs from entering the cell cycle. study HSCs