Dendritic cells(DC)are crucial cells of the immune system,and bridged the essential connection between innate and adaptive immunity.They reside in the periphery as sentinels where they take up antigens.Upon activation...Dendritic cells(DC)are crucial cells of the immune system,and bridged the essential connection between innate and adaptive immunity.They reside in the periphery as sentinels where they take up antigens.Upon activation, they migrate to lymphoid organs and present there the processed antigens to T cells,thereby activating them and eliciting a potent immune response.Dendritic cells are bone marrow-derived cells,still big controversies exist about their in vivo development.In vitro,DC can be generated from multiple precursor cells,among them lymphoid and myeloid committed progenitors.Although it remains unknown how DC are generated in vivo, studying the functions of in vitro generated DC results in fundamental knowledge of the DC biology with promising applications for future medicine.Therefore,in this review,we present current protocols for the generation of DC from precursors in vitro.We will do this for the mouse system,where most research occurs and for the human system,where research concentrates on implementing DC biology in disease treatments.Cellular & Molecular Immunology.2005;2(1):28-35.展开更多
Ever since hematopoietic stem cells(HSCs)were first identified half a century ago,their differentiation roadmap has been extensively studied.The classical model of hematopoiesis has long held as a dogma that HSCs resi...Ever since hematopoietic stem cells(HSCs)were first identified half a century ago,their differentiation roadmap has been extensively studied.The classical model of hematopoiesis has long held as a dogma that HSCs reside at the top of a hierarchy in which HSCs possess self-renewal capacity and can progressively give rise to all blood lineage cells.However,over the past several years,with advances in single cell technologies,this developmental scheme has been challenged.In this review,we discuss the evidence supporting heterogeneity within HSC and progenitor populations as well as the hierarchical models revised by novel approaches mainly in mouse system.These evolving views provide further understanding of hematopoiesis and highlight the complexity of hematopoietic differentiation.展开更多
Spaceflight-associated immune system weakening ultimately limits the ability of humans to expand their presence beyond the earth's orbit. A mechanistic study of microgravity-regulated immune cell function is neces...Spaceflight-associated immune system weakening ultimately limits the ability of humans to expand their presence beyond the earth's orbit. A mechanistic study of microgravity-regulated immune cell function is necessary to overcome this challenge. Here, we demonstrate that both spaceflight (real) and simulated microgravity significantly reduce macrophage differentiation, decrease macrophage quantity and functional polarization, and lead to metabolic reprogramming, as demonstrated by changes in gene expression profiles. Moreover, we identified RAS/ERK/NFκB as a major microgravity-regulated pathway. Exogenous ERK and NFκB activators significantly counteracted the effect of microgravity on macrophage differentiation. In addition, microgravity also affects the p53 pathway, which we verified by RT-qPCR and Western blot. Collectively, our data reveal a new mechanism for the effects of microgravity on macrophage development and provide potential molecular targets for the prevention or treatment of macrophage differentiation deficiency in spaceflight.展开更多
Studies on coding genes, miRNAs, and lncRNAs during erythroid development have been performed in recent years. However, analysis focusing on the integration of the three RNA types has yet to be done. In the present st...Studies on coding genes, miRNAs, and lncRNAs during erythroid development have been performed in recent years. However, analysis focusing on the integration of the three RNA types has yet to be done. In the present study, we compared the dynamics of coding genes, miRNA, and IncRNA expression profiles. To explore dynamic changes in erythropoiesis and potential mechanisms that control these changes in the transcriptome level, we took advantage of high throughput sequencing technologies to obtain transcriptome data from cord blood hematopoietic stem cells and the following four erythroid differentiation stages, as well as from mature red blood cells. Results indicated that lncRNAs were promising cell marker candidates for erythroid differentiation. Clustering analysis classified the differentially expressed genes into four subtypes that corresponded to dynamic changes during sternness maintenance, mid-differentiation, and maturation. Integrated analysis revealed that noncoding RNAs potentially participated in controlling blood cell maturation, and especially associated with heine metabolism and responses to oxygen species and DNA damage. These regulatory interactions were displayed in a comprehensive network, thereby inferring correlations between RNAs and their associated functions. These data provided a substantial resource for the study of normal erythropoiesis, which will permit further investigation and understanding of erythroid development and acquired erythroid disorders.展开更多
Background:The conversion of adenosine(A)to inosine(I)through deamination is the prevailing form of RNA editing,impacting numerous nuclear and cytoplasmic transcripts across various eukaryotic species.Millions of high...Background:The conversion of adenosine(A)to inosine(I)through deamination is the prevailing form of RNA editing,impacting numerous nuclear and cytoplasmic transcripts across various eukaryotic species.Millions of high-confidence RNA editing sites have been identified and integrated into various RNA databases,providing a convenient platform for the rapid identification of key drivers of cancer and potential therapeutic targets.However,the available database for integration of RNA editing in hematopoietic cells and hematopoietic malignancies is still lacking.Methods:We downloaded RNA sequencing(RNA-seq)data of 29 leukemia patients and 19 healthy donors from National Center for Biotechnology Information(NCBI)Gene Expression Omnibus(GEO)database,and RNA-seq data of 12 mouse hematopoietic cell populations obtained from our previous research were also used.We performed sequence alignment,identified RNA editing sites,and obtained characteristic editing sites related to normal hematopoietic development and abnormal editing sites associated with hematologic diseases.Results:We established a new database,"REDH",represents RNA editome in hematopoietic differentiation and malignancy.REDH is a curated database of associations between RNA editome and hematopoiesis.REDH integrates 30,796 editing sites from 12 murine adult hematopoietic cell populations and systematically characterizes more than 400,000 edited events in malignant hematopoietic samples from 48 cohorts(human).Through the Differentiation,Disease,Enrichment,and knowledge modules,each A-to-I editing site is systematically integrated,including its distribution throughout the genome,its clinical information(human sample),and functional editing sites under physiological and pathological conditions.Furthermore,REDH compares the similarities and differences of editing sites between different hematologic malignancies and healthy control.Conclusions:REDH is accessible at http://www.redhdatabase.com/.This user-friendly database would aid in understanding the mechanisms of RN展开更多
Human pluripotent stem cells(hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are promising sources for hematopoietic cells due to their unlimited growth capacity and the pluripot...Human pluripotent stem cells(hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are promising sources for hematopoietic cells due to their unlimited growth capacity and the pluripotency. Dendritic cells(DCs), the unique immune cells in the hematopoietic system, can be loaded with tumor specific antigen and used as vaccine for cancer immunotherapy. While autologous DCs from peripheral blood are limited in cell number, hPSC-derived DCs provide a novel alternative cell source which has the potential for large scale production. This review summarizes recent advances in differentiating hPSCs to DCs through the intermediate stage of hematopoietic stem cells. Step-wise growth factor induction has been used to derive DCs from hPSCs either in suspension cultureof embryoid bodies(EBs) or in co-culture with stromal cells. To fulfill the clinical potential of the DCs derived from hPSCs, the bioprocess needs to be scaled up to produce a large number of cells economically under tight quality control. This requires the development of novel bioreactor systems combining guided EB-based differentiation with engineered culture environment. Hence, recent progress in using bioreactors for hPSC lineage-specific differentiation is reviewed. In particular, the potential scale up strategies for the multistage DC differentiation and the effect of shear stress on hPSC differentiation in bioreactors are discussed in detail.展开更多
BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect...BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet known.As a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and differentiation.However,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or cells.We propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of HSCs.AIM To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and differentiation.METHODS CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental requirements.Flow cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured cells.Real-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant enzymes.Dichloro-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array.RESULTS Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all P<0.05).The ST-HSCs ratio and fold expansion of the 5 mmol/L NAM group were significantly higher than those of the control and 10 mmol/L N展开更多
Human pluripotent stem cells(hPSCs)have been suggested as a potential source for the production of blood cells for clinical application.In two decades,almost all types of blood cells can be successfully generated from...Human pluripotent stem cells(hPSCs)have been suggested as a potential source for the production of blood cells for clinical application.In two decades,almost all types of blood cells can be successfully generated from hPSCs through various differentiated strategies.Meanwhile,with a deeper understanding of hematopoiesis,higher efficiency of generating progenitors and precursors of blood cells from hPSCs is achieved.However,how to generate large-scale mature functional cells from hPSCs for clinical use is still difficult.In this review,we summarized recent approaches that generated both hematopoietic stem cells and mature lineage cells from hPSCs,and remarked their efficiency and mechanisms in producing mature functional cells.We also discussed the major challenges in hPSC-derived products of blood cells and provided some potential solutions.Our review summarized efficient,simple,and defined methodologies for developing good manufacturing practice standards for hPSC-derived blood cells,which will facilitate the translation of these products into the clinic.展开更多
目的研究衰老骨髓基质细胞对骨髓造血细胞增殖分化能力的影响,为阐述机体造血微环境衰老对造血干/祖细胞增殖的影响提供实验依据。方法全骨髓贴壁法体外培养大鼠骨髓基质细胞,分为对照组和衰老组。衰老组:常规培养基内加入30 mg/m L D-...目的研究衰老骨髓基质细胞对骨髓造血细胞增殖分化能力的影响,为阐述机体造血微环境衰老对造血干/祖细胞增殖的影响提供实验依据。方法全骨髓贴壁法体外培养大鼠骨髓基质细胞,分为对照组和衰老组。衰老组:常规培养基内加入30 mg/m L D-半乳糖作用48 h。CCK-8法测定BMSCs增殖;流式细胞术分析细胞周期;β-半乳糖苷酶(SA-β-Gal)染色观察衰老BMSCs百分率;Western blot检测P16、P21和P53蛋白表达。骨髓造血细胞与BMSCs共培养,集落计数检测髓系多向性造血祖细胞(CFU-Mix)增殖分化。ELISA检测BMSCs培养上清液中IL-1β、GM-CSF和SCF含量;DCFH-DA流式荧光检测BMSC活性氧簇(ROS)水平;酶学法检测BMSCs内过氧化物丙二醛(MDA)含量和总超氧化物歧化酶(SOD)活性。结果与对照组相比,D-半乳糖诱导BMSCs衰老,细胞阻滞于G0/G1期(P<0.01),增殖能力显著下降,SA-β-Gal染色阳性率升高(P<0.01);衰老相关蛋白P16、P21和P53表达明显上调(P<0.01)。与衰老BMSCs共培养的骨髓造血细胞增殖分化能力减弱。衰老BMSCs内ROS、MDA氧化损伤指标上升,SOD抗氧化指标下降(P<0.01);BMSCs培养上清液IL-1β、GM-CSF和SCF含量明显下降(P<0.01)。结论衰老骨髓基质细胞抑制造血细胞增殖、分化能力,其机制可能与骨髓基质细胞氧化损伤,分泌活性因子改变有关。展开更多
The onset of hematopoiesis in mammals is defined by generation of primitive erythrocytes and macrophage progenitors in embryonic yolk sac. Laboratories have met the challenge of transient and swiftly changing specific...The onset of hematopoiesis in mammals is defined by generation of primitive erythrocytes and macrophage progenitors in embryonic yolk sac. Laboratories have met the challenge of transient and swiftly changing specification events from ventral mesoderm through multipotent progenitors and maturing lineage-restricted hematopoietic subtypes, by developing powerful in vitro experimental models to interrogate hematopoietic ontogeny. Most importantly, studies of differentiating embryonic stem cell derivatives in embryoid body and stromal coculture systems have identified crucial roles for transcription factor networks （e.g. Gatal, Runxl, Scl） and signaling pathways （e.g. BMP, VEGF, WNT） in controlling stem and progenitor cell output. These and other relevant pathways have pleiotropic biological effects, and are often associated with early embryonic lethality in knockout mice. Further refinement in subsequent studies has allowed conditional expression of key regulatory genes, and isolation of progenitors via cell surface markers （e.g. FLK1） and reporter-tagged constructs, with the purpose of measuring their primitive and definitive hematopoietic potential. These observations continue to inform attempts to direct the differentiation, and augment the expansion, of progenitors in human cell culture systems that may prove useful in cell replacement therapies for hematopoietic deficiencies. The purpose of this review is to survey the extant literature on the use of differentiating murine embryonic stem cells in culture to model the developmental process of yolk sac hematopoiesis.展开更多
文摘Dendritic cells(DC)are crucial cells of the immune system,and bridged the essential connection between innate and adaptive immunity.They reside in the periphery as sentinels where they take up antigens.Upon activation, they migrate to lymphoid organs and present there the processed antigens to T cells,thereby activating them and eliciting a potent immune response.Dendritic cells are bone marrow-derived cells,still big controversies exist about their in vivo development.In vitro,DC can be generated from multiple precursor cells,among them lymphoid and myeloid committed progenitors.Although it remains unknown how DC are generated in vivo, studying the functions of in vitro generated DC results in fundamental knowledge of the DC biology with promising applications for future medicine.Therefore,in this review,we present current protocols for the generation of DC from precursors in vitro.We will do this for the mouse system,where most research occurs and for the human system,where research concentrates on implementing DC biology in disease treatments.Cellular & Molecular Immunology.2005;2(1):28-35.
基金supported by grants from the National Key Research and Development Program of China(2016YFA0100600,2017YFA0103400)the National Natural Science Foundation of China(81421002,81730006,81430004,81670106,81870086,8181101081)+1 种基金CAMS Initiative for Innovative Medicine(2017-I2M-3-009,2016-I2M-1-017)and the CAMS Fundamental Research Funds for Central Research Institutes(2016GH3100001,2018PT31005).
文摘Ever since hematopoietic stem cells(HSCs)were first identified half a century ago,their differentiation roadmap has been extensively studied.The classical model of hematopoiesis has long held as a dogma that HSCs reside at the top of a hierarchy in which HSCs possess self-renewal capacity and can progressively give rise to all blood lineage cells.However,over the past several years,with advances in single cell technologies,this developmental scheme has been challenged.In this review,we discuss the evidence supporting heterogeneity within HSC and progenitor populations as well as the hierarchical models revised by novel approaches mainly in mouse system.These evolving views provide further understanding of hematopoiesis and highlight the complexity of hematopoietic differentiation.
基金supported by grants from the National Key Research and Development Program of China(2017YFA0105002,Y.Z.2017YFA0104402,L.L.)Joint Funds of the National Natural Science Foundation of China(U1738111,Y.Z.)+1 种基金the China Manned Space Flight Technology Project(TZ-1)the National Natural Science Foundation Youth Fund(31800741,L.S.).
文摘Spaceflight-associated immune system weakening ultimately limits the ability of humans to expand their presence beyond the earth's orbit. A mechanistic study of microgravity-regulated immune cell function is necessary to overcome this challenge. Here, we demonstrate that both spaceflight (real) and simulated microgravity significantly reduce macrophage differentiation, decrease macrophage quantity and functional polarization, and lead to metabolic reprogramming, as demonstrated by changes in gene expression profiles. Moreover, we identified RAS/ERK/NFκB as a major microgravity-regulated pathway. Exogenous ERK and NFκB activators significantly counteracted the effect of microgravity on macrophage differentiation. In addition, microgravity also affects the p53 pathway, which we verified by RT-qPCR and Western blot. Collectively, our data reveal a new mechanism for the effects of microgravity on macrophage development and provide potential molecular targets for the prevention or treatment of macrophage differentiation deficiency in spaceflight.
文摘Studies on coding genes, miRNAs, and lncRNAs during erythroid development have been performed in recent years. However, analysis focusing on the integration of the three RNA types has yet to be done. In the present study, we compared the dynamics of coding genes, miRNA, and IncRNA expression profiles. To explore dynamic changes in erythropoiesis and potential mechanisms that control these changes in the transcriptome level, we took advantage of high throughput sequencing technologies to obtain transcriptome data from cord blood hematopoietic stem cells and the following four erythroid differentiation stages, as well as from mature red blood cells. Results indicated that lncRNAs were promising cell marker candidates for erythroid differentiation. Clustering analysis classified the differentially expressed genes into four subtypes that corresponded to dynamic changes during sternness maintenance, mid-differentiation, and maturation. Integrated analysis revealed that noncoding RNAs potentially participated in controlling blood cell maturation, and especially associated with heine metabolism and responses to oxygen species and DNA damage. These regulatory interactions were displayed in a comprehensive network, thereby inferring correlations between RNAs and their associated functions. These data provided a substantial resource for the study of normal erythropoiesis, which will permit further investigation and understanding of erythroid development and acquired erythroid disorders.
基金supported by grants from the National Key Research and Development Program of China(Nos.2022YFA1106300,2019YFA0802603,2019YFA0801800,2019YFA0111700,and 2021YFA0805703)the National Natural Science Foundation of China(Nos.92268205,82122005,81970154,81970101,82270192)+1 种基金CAMS Innovation Fund for Medical Sciences(No.2021-I2M-1-019)Haihe Laboratory of Cell Ecosystem Innovation Fund(No.22HHXBSS00027)
文摘Background:The conversion of adenosine(A)to inosine(I)through deamination is the prevailing form of RNA editing,impacting numerous nuclear and cytoplasmic transcripts across various eukaryotic species.Millions of high-confidence RNA editing sites have been identified and integrated into various RNA databases,providing a convenient platform for the rapid identification of key drivers of cancer and potential therapeutic targets.However,the available database for integration of RNA editing in hematopoietic cells and hematopoietic malignancies is still lacking.Methods:We downloaded RNA sequencing(RNA-seq)data of 29 leukemia patients and 19 healthy donors from National Center for Biotechnology Information(NCBI)Gene Expression Omnibus(GEO)database,and RNA-seq data of 12 mouse hematopoietic cell populations obtained from our previous research were also used.We performed sequence alignment,identified RNA editing sites,and obtained characteristic editing sites related to normal hematopoietic development and abnormal editing sites associated with hematologic diseases.Results:We established a new database,"REDH",represents RNA editome in hematopoietic differentiation and malignancy.REDH is a curated database of associations between RNA editome and hematopoiesis.REDH integrates 30,796 editing sites from 12 murine adult hematopoietic cell populations and systematically characterizes more than 400,000 edited events in malignant hematopoietic samples from 48 cohorts(human).Through the Differentiation,Disease,Enrichment,and knowledge modules,each A-to-I editing site is systematically integrated,including its distribution throughout the genome,its clinical information(human sample),and functional editing sites under physiological and pathological conditions.Furthermore,REDH compares the similarities and differences of editing sites between different hematologic malignancies and healthy control.Conclusions:REDH is accessible at http://www.redhdatabase.com/.This user-friendly database would aid in understanding the mechanisms of RN
基金Supported by In part by Florida State University start up fundFlorida State University Research Foundation GAP awardthe partial support from National Science Foundation,No.1342192
文摘Human pluripotent stem cells(hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are promising sources for hematopoietic cells due to their unlimited growth capacity and the pluripotency. Dendritic cells(DCs), the unique immune cells in the hematopoietic system, can be loaded with tumor specific antigen and used as vaccine for cancer immunotherapy. While autologous DCs from peripheral blood are limited in cell number, hPSC-derived DCs provide a novel alternative cell source which has the potential for large scale production. This review summarizes recent advances in differentiating hPSCs to DCs through the intermediate stage of hematopoietic stem cells. Step-wise growth factor induction has been used to derive DCs from hPSCs either in suspension cultureof embryoid bodies(EBs) or in co-culture with stromal cells. To fulfill the clinical potential of the DCs derived from hPSCs, the bioprocess needs to be scaled up to produce a large number of cells economically under tight quality control. This requires the development of novel bioreactor systems combining guided EB-based differentiation with engineered culture environment. Hence, recent progress in using bioreactors for hPSC lineage-specific differentiation is reviewed. In particular, the potential scale up strategies for the multistage DC differentiation and the effect of shear stress on hPSC differentiation in bioreactors are discussed in detail.
基金the Science and Technology Department of Shanxi Province,No.YDZJSX2021B009Health Commission of Shanxi Province,No.2021XM07Shanxi Provincial Department of Education,No.2023KY380.
文摘BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet known.As a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and differentiation.However,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or cells.We propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of HSCs.AIM To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and differentiation.METHODS CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental requirements.Flow cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured cells.Real-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant enzymes.Dichloro-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array.RESULTS Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all P<0.05).The ST-HSCs ratio and fold expansion of the 5 mmol/L NAM group were significantly higher than those of the control and 10 mmol/L N
基金supported by grants from the National Key Research and Development Program of China(2022YFA1103500)Natural Science Foundation of China(Grant No.8220010141,82200233,82222003,92268117,82161138028)+2 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ22H080005)Sanming Project of Medicine in Shenzhen(Grant No.SZSM202111004)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2020R01006).
文摘Human pluripotent stem cells(hPSCs)have been suggested as a potential source for the production of blood cells for clinical application.In two decades,almost all types of blood cells can be successfully generated from hPSCs through various differentiated strategies.Meanwhile,with a deeper understanding of hematopoiesis,higher efficiency of generating progenitors and precursors of blood cells from hPSCs is achieved.However,how to generate large-scale mature functional cells from hPSCs for clinical use is still difficult.In this review,we summarized recent approaches that generated both hematopoietic stem cells and mature lineage cells from hPSCs,and remarked their efficiency and mechanisms in producing mature functional cells.We also discussed the major challenges in hPSC-derived products of blood cells and provided some potential solutions.Our review summarized efficient,simple,and defined methodologies for developing good manufacturing practice standards for hPSC-derived blood cells,which will facilitate the translation of these products into the clinic.
文摘The onset of hematopoiesis in mammals is defined by generation of primitive erythrocytes and macrophage progenitors in embryonic yolk sac. Laboratories have met the challenge of transient and swiftly changing specification events from ventral mesoderm through multipotent progenitors and maturing lineage-restricted hematopoietic subtypes, by developing powerful in vitro experimental models to interrogate hematopoietic ontogeny. Most importantly, studies of differentiating embryonic stem cell derivatives in embryoid body and stromal coculture systems have identified crucial roles for transcription factor networks （e.g. Gatal, Runxl, Scl） and signaling pathways （e.g. BMP, VEGF, WNT） in controlling stem and progenitor cell output. These and other relevant pathways have pleiotropic biological effects, and are often associated with early embryonic lethality in knockout mice. Further refinement in subsequent studies has allowed conditional expression of key regulatory genes, and isolation of progenitors via cell surface markers （e.g. FLK1） and reporter-tagged constructs, with the purpose of measuring their primitive and definitive hematopoietic potential. These observations continue to inform attempts to direct the differentiation, and augment the expansion, of progenitors in human cell culture systems that may prove useful in cell replacement therapies for hematopoietic deficiencies. The purpose of this review is to survey the extant literature on the use of differentiating murine embryonic stem cells in culture to model the developmental process of yolk sac hematopoiesis.
文摘目的本文以斑马鱼(Danio rerio)为研究对象,探讨了低氧对早期胚胎发育、造血分化和红系分化的影响。方法选取受精后12 h的斑马鱼胚胎,随机分为两组,以常氧组为对照组,低氧组为实验组,实时观察斑马鱼胚胎发育形态学的变化;通过联苯胺染色、邻联茴香胺染色、AO染色及瑞氏吉姆萨染色观察红细胞的生成及形态学变化;并通过Real time PCR检测了斑马鱼胚胎造血相关基因的表达情况。结果与常氧相比,低氧降低了斑马鱼胚胎卵黄囊的营养消耗,抑制了色素细胞的形成,减慢了心率,延缓了斑马鱼胚胎的孵化,观察和分析了低氧对红细胞产生和成熟的抑制作用。结论低氧延缓了斑马鱼胚胎发育,抑制了红细胞的产生和成熟。
