Stimulation of Hematopoiesis in Untreated and Cyclophosphamide Treated Mice by the Inhibition of Prostaglandin Synthesis

Indomethacin (IN) was administered to untreated or to cyclophosphamide (CY) treated C57B1/6 mice to study the roles of prostaglandins in regulating hematopoiesis. The following hematopoietic parameters were quantitated: 1) peripheral blood leukocyte (PBL) count; 2) total nucleated cells per spleen; 3) total nucleated cells per femur; and 4) spleen weight. Assays were performed in vitro to measure the number of colony forming units (CFU) present in the bone marrow and spleen. Untreated mice administered IN had a transient rise in their PBL count. These animals also developed splenomegaly and had an increased number of nucleated cells in their spleen. All CY treated mice had a marked decrease in PBL count, spleen cellularity, bone marrow cellularity, and spleen size during the first 5 days after CY treatment. These observations were followed by hematopoietic recovery over the next 10 days. Cyclophosphamide treated mice exhibited a more rapid hematopoietic recovery when treated with IN than without IN treatment. Analysis of the CFU capacity of bone marrow and spleen cells in soft agar showed a larger number of CFU in the bone marrow and spleen of IN treated mice or of CY/IN treated mice than in animals not receiving IN. These results indicate that prostaglandins are involved in the regulation of hematopoiesis in untreated mice and that prostaglandins may limit the hematopoietic recovery of CY treated mice.     

The Effect of Two Glucan Carboxymethyl Derivatives with Various Substitution Degrees on Cyclophosphamide Immunosuppression in Mice

Abstract

Carboxymethylglucan (CMG)¹ in two different degrees of substitution of carboxymethyl groups (0.56 and 0.89) was administered to cyclophoshamide (CY) treated (200 mg/kg) C57B1/6 mice in three doses (10, 50, and 100 mg/kg) 24 h after CY. The influence of CMG administration on the cell suppression caused by CY was observed in the subsequent days. The cellularity of spleen, bone marrow and peripheral blood was quantified on days 2, 5, 8, 11, 15, and 21 after CY treatment.

CY treated mice developed a significant decrease in peripheral blood cell counts, and spleen and bone marrow cellularity during the initial 5 days, followed by recovery in the next 15 days, with an overshoot reaction in spleen cellularity and erythrocyte levels.

The initial cellularity depression and the following recovery was modified by both carboxymethyl derivatives of glucan. Cyclophosphamide treated mice exhibited less pronounced immunosuppression and more rapid hematopoietic recovery when administered with CMG, althought this reaction was only of a modest degree. The effects were not dose dependent and the differences between the two glucans were not significant.     

The Effect of Two Glucan Carboxymethyl Derivatives with Various Substitution Degrees on Cyclophosphamide Immunosuppression in Mice

Carboxymethylglucan (CMG)¹ in two different degrees of substitution of carboxymethyl groups (0.56 and 0.89) was administered to cyclophoshamide (CY) treated (200 mg/kg) C57B1/6 mice in three doses (10, 50, and 100 mg/kg) 24 h after CY. The influence of CMG administration on the cell suppression caused by CY was observed in the subsequent days. The cellularity of spleen, bone marrow and peripheral blood was quantified on days 2, 5, 8, 11, 15, and 21 after CY treatment.

CY treated mice developed a significant decrease in peripheral blood cell counts, and spleen and bone marrow cellularity during the initial 5 days, followed by recovery in the next 15 days, with an overshoot reaction in spleen cellularity and erythrocyte levels.

The initial cellularity depression and the following recovery was modified by both carboxymethyl derivatives of glucan. Cyclophosphamide treated mice exhibited less pronounced immunosuppression and more rapid hematopoietic recovery when administered with CMG, althought this reaction was only of a modest degree. The effects were not dose dependent and the differences between the two glucans were not significant.     

八珍汤对血虚模型小鼠造血调控因子影响的实验研究

探讨八珍汤对由环磷酰胺引起的小鼠骨髓造血功能抑制的调控作用。采用环磷酰胺致小鼠血虚模型 ,测定八珍汤对骨髓抑制小鼠外周血象及其细胞因子产生的影响。结果表明 ,八珍汤对环磷酰胺所致血虚模型小鼠骨髓细胞有促进增殖作用 ;经八珍汤诱导制备的巨噬细胞、脾细胞、肺条件培养液和骨骼肌条件培养液能促进血虚模型小鼠骨髓细胞增殖 ,促进血虚模型小鼠骨髓基质细胞分泌肿瘤坏死因子 (TNF)。八珍汤对环磷酰胺所致化疗损伤的造血调控作用可能与直接或间接刺激造血微环境的基质细胞分泌正性和负性造血生长因子有关。     

小鼠同种异基因骨髓腔内骨髓移植促进早期造血功能重建

目的探讨同种异基因骨髓腔内骨髓移植(IBM-BMT)对小鼠早期造血功能重建的影响。方法将BALB/c小鼠骨髓单个核细胞(BMNCs)分别用胫骨骨髓腔内注射(IBMI)和尾静脉注射(IV)两种方法移植入经致死量60Coγ射线辐照后的60只C57BL/6小鼠。受鼠随机分为3组:骨髓腔内注射高和低剂量组(IBM1和IBM2组)、尾静脉注射组(IV组),每组20只。在骨髓移植后1、3、6和9d分别计数各组受鼠胫骨骨髓腔内有核细胞总数,并用流式细胞术检测供体植入水平(供体来源有核细胞总数、供体来源髓系细胞数)。结果于移植后6d,IBM1组和IBM2组注射侧胫骨骨髓腔内有核细胞总数、供体来源有核细胞总数、供体来源髓系细胞总数均明显高于IV组(P<0.05或P<0.01?。结论IBM-BMT较IV-BMT更能促进同种异基因骨髓移植后的早期造血功能重建。     

Effect of pregnancy on the activity of hematopoietic stem cells

Effect of allogenic and syngenic pregnancy on the activity of multifunctional hematopoietic stem cells of bone marrow and spleen was studied. It was observed that bone marrow of mice mated syngenically and allogenically was more capable of restoring hematopoiesis in lethally irradiated recipients as compared to the bone marrow of nonpregnant mice. Increased number of colony forming hematopoietic cells (CFU-S) was recorded also in the spleen of female mice with syngenic pregnancy. When the spleen of pregnant mice mated allogenically, was the source of the multifunctional hematopoietic spleen cells, the animals displayed suppressed capability to restore hematopoiesis which manifested by a decreased number of CFU-S. Splenectomy appeared to have no influence upon the number of CFU-S in the bone marrow of pregnant mice mated allogenically.     

Differential induction of hematopoiesis and immune suppressor cells in the bone marrow versus in the spleen by Lewis lung carcinoma variants

Mice bearing large (greater than or equal to 3 g) metastatic and nonmetastatic Lewis lung carcinoma (LLC) tumors were studied to determine if the tumor variants differentially induced bone marrow versus splenic hematopoiesis and the appearance of hematopoiesis-associated immune suppressor cells. The metastatic LLC-C3 and nonmetastatic LLC-C8 tumors were equal in their stimulatory effects in vivo on both the number of bone marrow myeloid progenitor cells (CFU) and the appearance of bone marrow immune suppressor cells. In contrast, the tumor variants differed in their effects on the spleen, with the metastatic tumors causing a more pronounced increase in the number of nucleated cells and CFU, a reduced blastogenic responsiveness to concanavalin (Con-A), and an increased suppressor cell activity than nonmetastatic LLC-C8 tumors. The splenic suppressor cells of mice bearing large LLC-C3 tumors resembled the bone marrow suppressor cells which we previously described (Young et al.: Cancer Res. 47, 100, 1987) in that they were nonadherent to nylon wool, sensitive to treatment with L-leucine methyl ester, insensitive to treatment with complement and Thy-1.2, MG-1.2, asialo-GM1, or anti-IgM antibodies, and mediated their suppression through a mechanism which was only partially indomethacin sensitive. The stimulatory effects on hematopoiesis and suppressor cells by the LLC variant tumors may have been mediated by the tumor-derived colony stimulating factor (CSF) activities. Bone marrow cell proliferation and colony formation were stimulated in vitro by culture supernatants of metastatic LLC-C3 cells and, to a lesser degree, of nonmetastatic LLC-C8 cells. These colony-stimulating factor (CSF)-containing supernatants also induced normal bone marrow cells to become immune suppressive. In contrast, supernatants of only LLC-C3 cells, and not of LLC-C8 cells, stimulated in vitro growth of splenic CFU from LLC-C3-bearing mice; spleen cells from normal mice and from LLC-C8 bearers were unresponsive to supernatants of the LLC variants. These results suggest that CSF produced by either the metastatic LLC-C3 or the nonmetastatic LLC-C8 tumors could concurrently stimulate bone marrow hematopoiesis and the appearance of bone marrow suppressor cells. However, the metastatic LLC-C3 tumor cells, and not the nonmetastatic LLC-C8 cells, could also cause expansion of progenitor cells and hematopoiesis to the spleen and, consequently, induce the appearance in the spleen of hematopoiesis-associated immune suppressor cells.     

Identification of a massive reserve of hematopoietic progenitors in mice

Previous studies have demonstrated that mice null (-/-) for either CD34 or c-mpl are viable and have greatly decreased numbers of multipotential (CFU-Mix), erythroid (BFU-E), and granulocytemacrophage (CFU-GM) progenitor cells in the bone marrow (BM), spleen (Spl) and peripheral blood (PB), without noticeable decreases in the nucleated cellularity of these organs. To evaluate the significance of these two proteins further, mice null for both CD34 and c-mpl were assessed for hematopoietic progenitor cells (HPC) and nucleated cellularity and compared with these cells in CD34-/- and c-mpl-/- mice. The following progenitors were assessed: CFU-GM, BFU-E, CFU-Mix with an erythroid component, CFU-Mix with erythroid and megakaryocyte components, nonerythroid CFU with a megakaryocyte (Meg) component and pure CFU-Meg. Results demonstrated significant decreases in progenitors in the BM of dual CD34/c-mpl-/- mice compared to decreases from CD34-/- or c-mpl-/- mice; progenitor numbers in CD34/c-mpl-/- mice were decreased by 83-99.3% compared to that in wild-type littermate control mice. Decreases in progenitors in spleens of c-mpl-/- mice (89-96%) were more drastic than those of CD34-/- mice (50-78%) whereas those of dual CD34/c-mpl-/- mice were equal to or lower than that of c-mpl-/- mice (93-98%). Decreases in PB progenitors were seen in the c-mpl-/- and dual CD34/c-mpl-/- mice (75-90%). Whereas progenitor cells in BM, Spl and PB were drastically reduced in dual CD34/c-mpl-/- mice compared to controls, absolute numbers of nucleated cells in these organs were essentially not reduced. These studies demonstrate that CD34 and c-mpl have non-redundant effects on maintenance of steady-state hematopoiesis and highlight how few progenitor cells are required in steady-state conditions to populate and maintain the BM, Spl, and PB with nucleated cells.     

大鼠骨髓间质干细胞对同种骨髓移植后造血重建和免疫重建的作用

目的：探讨大鼠骨髓间质干细胞（MSC）对 同种异体骨髓移植造血重建和免疫重建的影响。方法:建立大鼠同种异 体骨髓移植模型，通过生存率分析、外周血象检测、免疫细胞计数和受体免疫功能检测，综 合评价MSC对骨髓移植(bone marrow transplantation,BMT)后造血重建和免疫重建的作用。 结果：(1) MSC可促进BMT后造血重建：移植后30 d，共移植组外周血白 细胞、淋巴细胞和血小板数均高于单纯骨髓移植组；共移植组骨髓细胞数也高于对照组。(2 )MSC可促进BMT后免疫重建：移植后30 d，共移植组胸腺细胞数、脾细胞总数均高于骨髓单 纯移植组；共移植组对ConA、LPS 刺激的淋巴细胞增殖反应以及对第三体来源的同种混合淋 巴细胞反应均强于单纯BMT组。结论：大鼠MSC与骨髓共移植对同种异体 骨髓移植造血重建和免疫重建有一定促进作用。     

人参二醇组皂苷对再生障碍性贫血小鼠造血组织MAPK/ERK信号通路的诱导作用

目的:观察人参二醇组皂苷(PDS)对免疫介导型再生障碍性贫血(简称再障)小鼠骨髓细胞MAPK/ERK信号通路蛋白激酶及脾脏调节性T细胞的诱导作用,探讨其治疗再障的作用机制。方法:用[60Co]-γ射线5.0 Gy全身照射BALB/c小鼠,后经尾静脉输入DBA/2小鼠的淋巴细胞悬液,制备免疫介导型再障小鼠模型。60只小鼠随机分为6组,即正常组,模型组,PDS低、中、高剂量组,环孢素组。不同浓度药物灌胃治疗14 d测定各组小鼠外周血象,观察骨髓病理切片,Western blot法及免疫组织化学法测定骨髓细胞MEK1/2、p-MEK1/2、ERK1/2和p-ERK1/2的蛋白水平,流式细胞术检测脾脏调节性T细胞比例。结果:再障小鼠外周血全血细胞减少,骨髓呈抑制状态;PDS治疗能够显著升高再障小鼠外周血象,增加脾脏调节性T细胞比例,呈剂量依赖性(P0.05)。PDS中、高剂量组显著上调骨髓细胞MEK1/2、p-MEK1/2、ERK1/2和p-ERK1/2的蛋白水平(P0.05)。结论:PDS能有效促进造血,上调再障模型小鼠骨髓细胞MAPK/ERK信号通路多种蛋白激酶的表达,可能是PDS促进骨髓造血功能恢复的作用机制之一。另外,PDS对再障模型小鼠的免疫功能有一定的调节作用。     

Cx43在造血调控及重建中的作用

目的:采用条件性基因敲除技术构建造血系统间隙连接蛋白43(Cx43)基因敲除(Cx43~(-/-))小鼠模型,并探讨Cx43在维持造血细胞自我更新及功能稳定中的作用。方法:将引进的2对转基因小鼠Cx43 loxP/loxP和Lyz-Cre/+杂交,选取F1雌性子代Cx43 loxP/-_Lyz-Cre/+与雄性Cx43 loxP/loxP合笼回配,提取所获得子代小鼠鼠尾组织基因组DNA,采用PCR方法鉴定小鼠基因型,RT-PCR方法筛选Cx43~(-/-)小鼠,同时分析小鼠不同器官中Cx43基因的表达差异;该类小鼠经5-氟尿嘧啶(5-FU;125 mg/kg)处理,在化疗前及化疗后第5、10和15天经眼球取血分析其血象变化。Cx43~(-/-)及Cx43~(+/+)小鼠予7.5 Gy(~(60)Co-γ)的致死量照射,剂量率1 Gy/min,照射后6 h分别给予事先准备就序的骨髓细胞,每只3×10~6细胞于尾静脉注入,2周后处死小鼠检测造血是否重建:分离股骨切片后,收集骨髓细胞进行细胞表型分析(选用的单抗为CD45R、Gr-1、CD4、 CD8a、TCRαβ、Mac-1、抗sIgM、TER119、Sca-1及CD117);同时进行体外造血细胞集落实验观察造血细胞的体外增殖能力。结果:本研究通过2种转基因小鼠间杂交和回交,成功获得造血系统选择性Cx43基因敲除小鼠;该类小鼠骨髓及外周血细胞无Cx43表达,参与造血的组织,如肝脏和脾脏中Cx43表达也显著下调(P0.01),而心脏和肾脏的Cx43表达则无影响,小鼠成年后外周血象分析并无明显异常,但应急代偿能力下降,经5-FU处理后,其造血功能恢复显著减缓,处理15 d后,Cx43~(+/+)小鼠造血功能已接近正常水平,而Cx43~(-/-)小鼠仍无明显的恢复迹象,血红蛋白、白细胞及血小板仍处低位,2者差别有统计学显著性(P0.01);体外集落试验也证实Cx43~(-/-)小鼠造血干/祖细胞的增殖能力下降,其CFU-GM或CFU-E集落数均明显少于Cx43~(+/+)小鼠(P0.01),但流式细胞术结果显示,Cx43~(-/-)小鼠骨髓中Lin~-/c-Kit~+/Sca-1~+细胞亚群数量与Cx43~(+/+)小鼠相比差异并无统计学显著性;Cx43~(-/-)小鼠在化疗或移植后其骨髓造血功能重建均延迟,且化疗15 d后骨髓切片及涂片均证实其骨髓中造血细胞增生程度明显降低,脂肪组织显著增多,而且T、B细胞发育也有异常。此外,其外周血中CD4~+CD8~+细胞比例比野生型小鼠增多(P0.05),但CD4~+T细胞显著减少(P0.01),尤其是TCRαβ亚群细胞减少最为明显(P0.01)。同样,Cx43~(-/-)小鼠外周血中CD45R~+sIgM~-细胞亚群比例与野生型小鼠相比显著减少(P0.01)。结论:骨髓中Cx43基因表达在造血干/祖细胞发育(尤其是应急状态时)具重要作用,敲除Cx43基因后造血干/祖细胞增殖减缓,造血及免疫重建功能受损。     

Granulocyte-colony stimulating factor impedes recovery from damage caused by cytotoxic agents through increased differentiation at the expense of self-renewal

G-CSF is routinely used to hasten recovery from chemotherapy-induced neutropenia. We have recently shown that G-CSF, when combined with stem cell-damaging cytotoxic agents, results in enhanced stem cell damage and loss of marrow reserve. To investigate the mechanisms of stem cell damage caused by G-CSF, we gave C57BL/6 (B6) mice repeated doses of cyclophosphamide ([CY] 84 mg/kg) or carmustine ([BCNU] 13.2 mg/kg) and G-CSF (250 microg/kg/day) for either four days or eight days. Two different regimens of G-CSF were chosen to study the influence of increased proliferation on hematopoiesis which was measured at the end of the first, third and sixth 14-day cycle of each cytotoxic agent and 7 and 20 weeks after completion of all cycles. A spectrum of hematopoietic indices was measured including WBC, bone marrow cellularity, granulocyte/macrophage-colony-forming cells (GM-CFC), colony-forming cells with high proliferative-potential (HPP-CFC), cobblestone area-forming cells ([CAFC]-day 7 and CAFC-day 28), and long-term marrow repopulating ability in vivo. Despite the absence of differences in peripheral blood cell counts or bone marrow cellularity 14 days after each dose, progenitor cell levels (HPP-CFC, GM-CFC, and CAFC-7) were increased up to 2.5-fold with cytotoxic agent and G-CSF administration compared with cytotoxic agent administration alone. Mice given G-CSF for eight days had the greatest number of progenitors suggesting a dose-response relationship for G-CSF administration. G-CSF resulted in a decrease in hematopoietic stem cell (CAFC-28) content when measured two weeks after each cycle of saline, CY, and BCNU. Twenty weeks after six cycles of BCNU, the reduction in stem cell levels persisted and was further decreased when G-CSF was added to BCNU for four or eight days. Data from this study suggest that the most likely explanation for the damaging effects of G-CSF is that G-CSF directly or indirectly induces stem cells to differentiate into more committed hematopoietic cells resulting in a loss of marrow reserve. This effect is enhanced in animals with an already compromised hematopoietic stem cell compartment as seen with repeated doses of BCNU.     

Hematopoietic organs of mice after a single injection oxyhydrocortisone

The method of exogenous cloning of hematopoietic stem cells (colony-forming units-CFU) in the spleen and bone marrow of lethally irradiated recipients was used to study the population kinetics and direction of differentiation of CFU from mice receiving a single dose (5 mg per mouse) of hydrocortisone. Against the background of prolonged involution of the lymphoid tissue changes took place in the population and differentiation of CFU. Meanwhile the CFU concentration in the spleen and femoral bone marrow of the mice remained constant. After administration of the hormone, the powers of differentiation of CFU from spleen and bone marrow changed sharply in opposite directions: Marrow CFU behaved like splenic CFU whereas splenic CFU behaved like marrow CFU of normal mice. It is suggested that these effects are due to redistribution of T lymphocytes and not to the direct cytotoxic action of hydrocortisone on the CFU population.Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 87, No. 1, pp. 16, January, 1979.     

Effects of fibroblast-mediated interleukin 3 and interleukin 6 gene therapy on hematopoiesis in mice treated with 5-fluorouracil

Fibroblast-mediated cytokine gene therapy has proven to be a promising strategy for restoring hematopoiesis following repeated chemotherapy. Interleukin 3 (IL-3) and interleukin 6 (IL-6) can synergistically promote the recovery of hematopoiesis following chemotherapy. In this investigation, combined use of fibroblast-mediated IL-3 and IL-6 gene therapy was tested for hematopoietic effects on mice with or without 5-fluorouracil administration. The results demonstrated that combined therapy with IL-3 gene-modified NIH3T3 cell (NIH3T3-IL-3) and IL-6 gene-modified fibroblast NIH3T3 cell (NIH3T3-IL-6) implantation achieves obvious stimulation of hematopoiesis in normal mice and accelerates recovery of hematopoiesis. In normal mice the quantities of platelets, neutrophils, and total white blood cells in peripheral blood increased significantly after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells. The numbers of colony-forming unit (CFU) granulocyte/macrophage (CFU-GM) and CFU megakaryocyte (CFU-MK) formed by stem cells in bone marrow was significantly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than after the implantation of NIH3T3-IL-3 alone, NIH3T3-IL-6 alone, or neomycin gene-modified NIH3T3 cells. In hematopoiesis-depressed mice induced by preinjection with 5-fluorouracil at the dose of 150 mg/kg before cell implantation, the platelets, neutrophils, and white blood cells showed accelerated recovery, and the numbers of CFU-GM and CFU-MK formed by bone marrow cells were also markedly higher after the combined implantation of NIH3T3-IL-3 and NIH3T3-IL-6 cells than in control groups. Our data show that combined use of fibroblast-mediated IL-3 and IL-6 gene therapy may be of clinical relevance for the recovery of hematopoietic depression for patients after chemotherapy. Received: 4 March 1998 / Accepted: 20 May 1998     

人脐血间充质干细胞移植修复骨髓造血损伤

文题释义：间充质干细胞：是一种多功能干细胞,由胚胎发育早期的中胚层发展而来,存在于人的各种组织、器官中,如骨、软骨、脂肪、外周血和肌肉等。骨髓组织中的间充质干细胞最多,但其在骨髓细胞中的比例仍很低,只有0.01%-1.00%,且年龄越大其含量越少,骨髓中的间充质干细胞分化能力也呈下降趋势。与骨髓相比,脐血中所含的间充质干细胞更加原始,因而有更强的增殖、分化能力。相较于骨髓间充质干细胞而言,人脐血间充质干细胞具有来源广泛、取材方便、无伦理方面的限制,使得人脐血间充质干细胞成为再生医学中的另一重要来源。骨髓造血损伤动物模型：建立骨髓造血损伤动物模型的方法有很多,主要分为物理方法、化学方法及物理化学方法等。物理方法包括各种射线,如X射线等,化学方法主要指以环磷酰胺为代表的烷化剂类化疗药物,而物理化学方法也叫混合性方法,联合应用放射线和化疗药物建立动物模型。  摘要背景：大多数研究间充质干细胞体外培养对造血干细胞的增殖作用和骨髓间充质干细胞移植可降低辐照引起的造血细胞死亡,增加骨髓细胞存活,修复造血功能,而少有研究人脐血间充质干细胞移植对骨髓造血损伤的修复。目的：探讨人脐血间充质干细胞对骨髓造血微环境的修复情况。方法：选用雄性BALB/c小鼠随机分为3组,实验组和对照组小鼠进行总剂量为6 Gy的X射线全身照射,建立骨髓造血损伤模型,正常组为未经处理的正常小鼠。实验组小鼠照射当天经尾静脉输入CM-DiL标记的人脐血间充质干细胞5×10⁶/只(0.2 mL),对照组和正常组经尾静脉输入生理盐水0.2 mL,移植后第1,5,7,14,21天观察外周血血象恢复情况和骨髓造血微环境修复情况。结果与结论：①外周血常规：移植后第1,5,7天,实验组和对照组小鼠与正常组小鼠比较,白细胞、血小板、红细胞计数及血红蛋白浓度进行性下降,第7天下降最为明显,移植后第14天三系较前有所恢复,移植后第21天基本恢复正常,与实验组相比,对照组三系下降更为明显,移植后第14天实验组较对照组恢复快;②骨髓涂片情况：移植后第1,5,7,14天实验组及对照组小鼠骨髓出现造血功能抑制,以第7天最为明显,移植后第14天骨髓增生较前有所恢复,实验组优于对照组;移植后第21天实验组及对照组小鼠骨髓造血功能恢复,与正常组相比无差异;③骨髓病理切片情况：移植后第1,5,7,14天实验组及对照组小鼠骨髓出现造血功能抑制;移植后第14天实验组及对照组小鼠的骨髓造血功能较前开始恢复,实验组小鼠的骨髓增生情况优于对照组小鼠, 移植后第21天实验组及对照组小鼠骨髓增生情况与正常组比较无差异;④结果表明,人脐血间充质干细胞对骨髓造血功能恢复均有明显促进作用。ORCID: 0000-0002-7547-9664(高坤莉) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Alpha4 integrins regulate the proliferation/differentiation balance of multilineage hematopoietic progenitors in vivo

We investigated roles of alpha4 integrins during hematopoiesis using mutant and chimeric mice. Yolk sac erythropoiesis and migration of hematopoietic progenitors to fetal liver, spleen, and bone marrow can occur without alpha4 integrins. Although terminal differentiation of these progenitors is possible without alpha4 integrins, these receptors are essential to maintain normal hematopoiesis in fetal liver, spleen, and bone marrow microenvironments. Moreover, alpha4-deficient erythroid progenitors and pre-B cells neither transmigrate beneath the stroma nor expand-properly in vitro. In contrast, alpha4-null cells migrate and differentiate efficiently into T lymphocytes within the thymus. In summary, alpha4 integrins are essential for normal development of all hematopoietic lineages in fetal liver, bone marrow, and spleen, likely by regulating the proliferation/differentiation balance of hematopoietic progenitors.     

Effects of organ-specific loss of insulin-like growth factor-I production on murine hematopoiesis.

To determine whether circulating insulin-like growth factor (IGF)-I has a role in hematopoiesis, we examined hematologic parameters in mice with markedly reduced serum levels resulting from a liver-specific inactivation of the IGF-I gene. These mice have normal postnatal growth and development, suggesting that local production of IGF-I can maintain anabolic effects. Liver-specific IGF-I-deficient (LID) mice were compared with control littermates with regard to hematopoietic parameters. Spleen cellularity was decreased in the LID mice compared with control mice. Spleen myeloid progenitors, as determined by colony-forming units-granulocyte/monocyte (CFU-GM) and colony-forming units-high proliferative potential (CFU-HPP), were significantly decreased in the LID mice. Immune parameters, as indicated by the absolute number of B and T cells, did not significantly differ between the knockout and control mice. In contrast to the decreased cellularity and myelopoiesis in the spleen, bone marrow cellularity was not different between the 2 groups, but the total femoral content of CFU-GM and CFU-HPP was significantly increased in the LID mice. The decrease in splenic myelopoiesis was not due to the inability of progenitors to exit the bone marrow, because CFU-GM and burst-forming units-erythroid were significantly increased in the blood of LID mice compared with normal littermates. Administration of exogenous IGF-I to the LID mice for 4 days partially restored myelopoietic parameters in the spleen. Liver production of IGF-I and, therefore, normal serum levels of this hormone, although not necessary for general organ growth and development, seems necessary for survival or transition of myeloid progenitors into the spleen.     

Radioprotection of haemopoietic stem cells by a single injection of bacterial lysate - IRS-19 administered to mice before or after irradiation

Data in this report describes the effect of a single injection of bacterial lysate IRS-19 prior to irradiation of C57Bl/6 mice on recovery of colony-forming cells (CFC) after sublethal and lethal doses of radiation. The injection of IRS-19 promoted an earlier recovery of colony-forming cells in the bone marrow and spleen. For example, 5 and 9 days after 7.5 Gy irradiation, the number of CFU-S per femur was approximately 1.7-2.3-fold higher in IRS-19-injected mice than in saline-injected mice. Also, pretreatment of mice with IRS-19 induced an increase in the number of endogenous haemopoietic stem cells (endoCFU-S). In the postradiation period (5-21 days) significantly increased bone marrow and spleen cellularity and accelerated myelopoietic regeneration (committed progenitor granulocyte-macrophage-colony-forming cells, GM-CFC) in the bone marrow and spleen compared with saline-treated controls. At the time of presumed irradiation, (i.e. 24 h after administration of the drug to the non-irradiated mice), there was no significant difference between the control mice and mice treated with IRS-19 in numbers of femoral and spleen GM-CFC. In contrast, the number of nucleated femoral cells decreased significantly in the group treated with IRS-19. Moreover, treatment with IRS-19 caused a sustained increase in serum colony-stimulating activity which was followed by an enhanced repopulation of GM-CFC in the femoral marrow and spleen. Administration of the agent 24 h prior to irradiation rather than postirradiation appeared most effective with respect to radioprotection. Intravenous rather than i.p. and p.o. was the most effective route of administration in the mouse. Furthermore, single, high-dose injection appeared to be more effective than repeated, lower dose injections. Results suggest that the radioprotective properties associated with the administration of IRS-19 are largely a consequence of the induction of haemopoietic colony-stimulating activities and potentially the activation and/or enhancement of cytokine cascades in the recipient animals. These changes may ultimately impact the cell cycle profile of the haemopoietic cells and therefore their ability to withstand and/or recover from radiation insult.     

Expression of v-src induces a myeloproliferative disease in bone-marrow-reconstituted mice

A recombinant retrovirus, N-TK-src, was used to introduce the v-src oncogene into mouse hematopoietic cells. This vector efficiently expresses both the neo and v-src genes in different hematopoietic lineages in culture as well as in mice reconstituted with infected bone marrow cells. Expression of v-src had no dramatic effect on the proliferative and differentiative capacity of hematopoietic precursors when assayed in methyl cellulose cultures. However, in mice reconstituted with N-TK-src-infected bone marrow cells, expression of v-src leads to the rapid development of a severe myeloproliferative disease, characterized by splenomegaly, anemia, and a shift of hematopoiesis from the bone marrow to the spleen.