A subpopulation of murine bone marrow cells fully differentiates along the myogenic pathway and participates in muscle repair in the mdx dystrophic mouse

Bone marrow (BM) transplantation in mice suggests the existence of pluripotent cells able to differentiate into skeletal muscle tissue, although sustained myofiber reconstitution has not yet been achieved. We investigated the myogenic potential of mouse BM cells and evaluated whether a BM fraction enriched for cells expressing skeletal muscle markers would ameliorate muscle repair, when compared to whole BM, into the dystrophic mdx mouse. We demonstrate that cells expressing striated-muscle-specific proteins are already present in the BM independently from experimentally forced myogenic conversion. We observed the presence of both markers of early myogenic program such as Pax3, Myf5, MyoD, desmin, and late myogenesis such as myosin heavy chain and alpha-sarcomeric actin. These myogenic cells are more represented in the early nonadherent BM fraction, which generates clones able to fully differentiate into myotubes. Transplantation in mdx mice by intravenous injection of whole BM and a tenfold BM myogenic enriched fraction resulted in BM reconstitution and limited dystrophin restoration. Taken together, these data show that a fraction of BM cells have a definite potential for differentiation along the skeletal muscle pathway and can be recruited by muscle repair mechanisms. They also indicate that factors limiting the degree of muscle recruitment and the host stem cell competition should be assessed in order to evaluate the usefulness of BM-derived myogenic cells into the context of cell-mediated gene therapy of inherited muscle diseases.     

Transplantation of bone marrow genetically engineered to express proinsulin II protects against autoimmune insulitis in NOD mice

BACKGROUND: Type 1 diabetes (T1D) is a T-cell-dependent autoimmune disease resulting from destructive inflammation (insulitis) of the insulin-producing pancreatic beta-cells. Transgenic expression of proinsulin II by a MHC class II promoter or transfer of bone marrow from these transgenic mice protects NOD mice from insulitis and diabetes. We assessed the feasibility of gene therapy in the NOD mouse as an approach to treat T1D by ex vivo genetic manipulation of normal hematopoietic stem cells (HSCs) with proinsulin II followed by transfer to recipient mice. METHODS: HSCs were isolated from 6-8-week-old NOD female mice and transduced in vitro with retrovirus encoding enhanced green fluorescent protein (EGFP) and either proinsulin II or control autoantigen. Additional control groups included mice transferred with non-manipulated bone marrow and mice which did not receive bone marrow transfer. EGFP-sorted or non-sorted HSCs were transferred into pre-conditioned 3-4-week-old female NOD mice and insulitis was assessed 8 weeks post-transfer. RESULTS: Chimerism was established in all major lymphoid tissues, ranging from 5-15% in non-sorted bone marrow transplants to 20-45% in EGFP-sorted bone marrow transplants. The incidence and degree of insulitis was significantly reduced in mice receiving proinsulin II bone marrow compared to controls. However, the incidence of sialitis in mice receiving proinsulin II bone marrow and control mice was not altered, indicating protection from insulitis was antigen specific. CONCLUSIONS: We show for the first time that ex vivo genetic manipulation of HSCs to express proinsulin II followed by transplantation to NOD mice can establish molecular chimerism and protect from destructive insulitis in an antigen-specific manner.     

Timing of transplantation of autologous bone marrow derived mesenchymal stem cells for treating myocardial infarction

It is still unclear whether the timing of intracoronary stem cell therapy affects the therapeutic response in patients with myocardial infarction.The natural course of healing the infarction and the presence of putative homing signals within the damaged myocardium appear to favor cell engraftment during the transendothelial passage in the early days after reperfusion.However,the adverse inflammatory environment,with its high oxidative stress,might be deleterious if cells are administered too early after reperfusion.Here we highlight several aspects of the timing of intracoronary stem cell therapy.Our results showed that transplantation of bone marrow mesenchymal stem cells at 2 4 weeks after myocardial infarction is more favorable for reduction of the scar area,inhibition of left ventricular remodeling,and recovery of heart function.Coronary injection of autologous bone marrow mesenchymal stem cells at 2 4 weeks after acute myocardial infarction is safe and does not increase the incidence of complications.     

供体骨髓干细胞输注联合肝移植治疗终末期肝病的近期效果观察

目的评价供体骨髓干细胞输注联合肝移植治疗终末期肝病的近期效果。方法2008年3月至2009年1月本中心30例肝移植受者分为两组,实验组8例,行同期供体骨髓干细胞联合肝脏移植;对照组22例,仅行肝脏移植,不行骨髓干细胞输注。观察两组受者术后免疫抑制剂（甲基强的松龙、他克莫司）用量、肝功能（谷氨酸转氨酶、天冬氨酸转氨酶等）变化、急性排斥反应和感染并发症发生情况,以及术后住院时间和费用。采用,检验、方差分析及确切概率法进行统计学分析。结果实验组术后甲基强的松龙总用量和出院时每日他克莫司用量显著低于对照组[甲基强的松龙分别为（1314±105）mg,（1884±256）mg,t=6．060,P=0．000;他克莫司分别为（3．73±0．35）mg／d,（4．93±0．62）mg／d,,=5．147,P=0．000]。术后第1天实验组血清谷氨酸转氨酶、天冬氨酸转氨酶均显著低于对照组[谷氨酸转氨酶分别为（875．2±325．5）IU／L,（1350．4±482．7）IU／L,t=2．543,P=0．016,天冬氨酸转氨酶分别为（646．2±184．9）IU／L,（1021．8±325．4）IU／L,t=3．067,P=0．005]。术后第3天也低于对照组[谷氨酸转氨酶分别为（252．9±35．8）IU／L,（343．5±47．8）IU／L,f=4．866,P=0．000,天冬氨酸转氨酶分别为（227．8±38．0）IU／L,（310．8±61．7）IU／L,t=3．545,P=0．001]。结论同期供体骨髓干细胞联合肝脏移植可以降低术后免疫抑制剂用量,减轻术后早期肝脏损伤,不增加治疗风险,是一种安全有效的治疗方法。     

骨髓基质细胞的特征及其在细胞和基因治疗中的应用

骨髓基质细胞是一类独特的间质干细胞,可分化为多种非造血系的组织。骨髓基质细胞具有贴壁生长的特性,因而易于在体外分离和扩增;另外骨髓基质细胞可在体内外表达多种治疗性的外湖目的基因。因此,骨髓基质细胞被认为是一种理想的治疗性细胞的基因治疗中的靶细胞。本文对骨髓基质细胞的研究进展及其在细胞和基因治疗中的应用作一综述。     

Effect and mechanism of acute graft versus host disease on early diffuse murine lung injury following allogeneic stem cell transplantation

To explore the effect and pathogenssis of acute graft-versus-host disease (aGVHD) on early diffuse lung injury in allogeneic hematopoietic stem cell transplantation (allo-HSCT), we established an aGVHD model of C57BL/6→BALB/c mice. Chest computed tomography (CT) scans, histopathology and the levels of cytokines including tumor necrosis factor α (TNFa) and Interferon (IFNg) in lungs were dynamically detected in recipient mice after transplantation. The incidence of aGVHD was respectively 0%, 0% and 100% in simple irradiation group (A), syngeneic transplant group(B) and allogeneic transplant group (C). Chest CT scans of recipient mice were normal in 3 groups on days +3 and +7 after transplantation. CT showed that two of ten mice had bilateral lung diffuse infiltrate on day +12 (on the brink of death) in group A and 6 of 10 mice had bilateral lung diffuse infiltrate on day +14 (3 d after aGVHD occurring) in group C, and were normal on days +12 and +14 in group B after transplantation. Histopathology of lungs in the 3 groups was similar, consisting of minor interstitial pneumonitis on day +3. Group A showed edema, hyperplasia of epithelial cells and widened alveolar interval on day +7, and epithelial cell necrosis, lymphocyte infiltration, hemorrhage, protein leakage, and local consolidation on day +12. The histopathology of group B showed slight edema of epithelial cells on +7 day, which were slighter than that on day +3, and virtually normal on day +14. The histopathology in group C was characterized by the significant expansion and congestion of capillaries, and lymphocyte infiltration on day +7, the acute pneumonitis was present involving tissue edema, lymphocyte and macrophage infiltration, protein leakage and perivascular inflammation on day +14. In group A, the levels of TNFa were lower on day +7 than on day +3. In group B, the levels of TNFa attained a peak on day +3, which decreased on days +7 and +14. In group C, the levels of TNFa were highest on day +7 and there was a significant difference between those on days +7 and +14 (P=0.816). In group A, the levels of IFNg on day +7 were higher than on day +3. In group B, the levels of IFNg increased progressively, but the comparison of IFNg levels in different times had no statistical significance (P=0.521, 0.118, 0.340). In group C, the levels of IFNg attained a peak by day +7 and decreased on day +14. aGVHD is the main cause of early non-infectious lung injury. T lymphocytes and TNFa are possibly implicated in the pathogenesis of acute GVHD-induced lung injury. The decreased levels of IFNg in lung tissues following transplantation might be associated with pulmonary fibrosis in late non-infectious pulmonary complications.     

Differentiation of embryonic stem cells in adult bone marrow

Embryonic stem cells (ESCs) are a potential source of generating transplantable hematopoietic stem and progenitor cells, which in turn can serve as "seed" cells for hematopoietic regeneration. In this study, we aimed to gauge the ability of mouse ESCs directly differentiating into hematopoietic cells in adult bone marrow (BM). To this end, we first derived a new mouse ESC line that constitutively expressed the green fluorescent protein (GFP) and then injected the ESCs into syngeneic BM via intra-tibia. The progeny of the transplanted ESCs were then analyzed at different time points after transplantation. Notably, however, most injected ESCs differentiated into non-hematopoietic cells in the BM whereas only a minority of the cells acquired hematopoietic cell surface markers. This study provides a strategy for evaluating the differentiation potential of ESCs in the BM micro-environment, thereby having important implications for the physiological maintenance and potential therapeutic applications of ESCs.     

Harnessing matrix stiffness to engineer a bone marrow niche for hematopoietic stem cell rejuvenation

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Distinct osteoblastic differentiation potential of murine fetal liver and bone marrow stroma-derived mesenchymal stem cells

Bone marrow-derived mesenchymal stem cells (MSC) are able to differentiate into osteoblasts under appropriate induction. Although MSC-derived osteoblasts are part of the hematopoietic niche, the nature of the stromal component in fetal liver remains elusive. Here, we determined the in vitro osteoblastic differentiation potential of murine clonal fetal liver-derived cells (AFT024, BFC012, 2012) in comparison with bone marrow-derived cell lines (BMC9, BMC10). Bone morphogenetic protein-2 (BMP2) increased alkaline phosphatase (ALP) activity, an early osteoblastic marker, in AFT024 and 2012 cells, whereas dexamethasone had little or no effect. BMP2, but not dexamethasone, increased ALP activity in BMC9 cells, and both inducers increased ALP activity in BMC10 cells. BMP2 increased ALP mRNA in AFT024, 2012 and BMC9 cells. By contrast, ALP was not detected in BMC10 and BFC012 cells. BMP2 and dexamethasone increased osteopontin and osteocalcin mRNA expression in 2012 cells. Furthermore, bone marrow-derived cells showed extensive matrix mineralization, whereas fetal liver-derived cell lines showed no or very limited matrix mineralization capacity. These results indicate that the osteoblast differentiation potential differs in bone marrow and fetal liver-derived cell lines, which may be due to a distinct developmental program or different microenvironment in the two hematopoietic sites.     

Ex vivo immunological evaluation of stable mixed chimeric patients after matched related donor allogeneic transplantation in sickle cell disease

Background aimsAllogeneic hematopoietic stem cell transplantation is curative for sickle cell disease, and the use of matched related donors, non-myeloablative conditioning and sirolimus immunosuppression results in stable mixed chimerism without graft-versus-host disease (GVHD). However, the time to terminate sirolimus while maintaining mixed chimerism is unclear.MethodsIn this study, we developed a two-way mixed lymphocyte reaction (MLR) to evaluate ex vivo immunoreaction in mixed chimeric patients.ResultsIn co-culture of peripheral blood mononuclear cells (PBMCs) from two healthy controls (without irradiation), we detected proliferation at various ratios of PBMC mixtures (1:9 to 9:1) as well as various concentrations of sirolimus, suggesting that two-way MLR is applicable to patients (having >10% chimerism) undergoing sirolimus treatment. In two-way MLR using PBMCs (including donor and recipient cells) from mixed chimeric patients (n = 28), greater ex vivo proliferation was observed <6 months compared with >6 months post-transplant and healthy control PBMC monoculture. Robust ex vivo proliferation was observed in a patient with acute GVHD, and persistent ex vivo proliferation (until 2 years) was observed in a patient with decreasing donor chimerism.ConclusionsIn summary, we demonstrated that in two-way MLR, ex vivo immunoreaction decreases to low levels ~6 months post-transplant. These findings suggest a rationale to continue immunosuppression for 6 months.     

Durable engraftment of genetically modified FVIII‐secreting autologous bone marrow stromal cells in the intramedullary microenvironment

Genetically modified FVIII‐expressing autologous bone marrow‐derived mesenchymal stromal cells (BMSCs) could cure haemophilia A. However, culture‐expanded BMSCs engraft poorly in extramedullary sites. Here, we compared the intramedullary cavity, skeletal muscle, subcutaneous tissue and systemic circulation as tissue microenvironments that could support durable engraftment of FVIII‐secreting BMSC in vivo. A zinc finger nuclease integrated human FVIII transgene into PPP1R12C (intron 1) of culture‐expanded primary canine BMSCs. FVIII‐secretory capacity of implanted BMSCs in each dog was expressed as an individualized therapy index (number of viable BMSCs implanted × FVIII activity secreted/million BMSCs/24 hours). Plasma samples before and after implantation were assayed for transgenic FVIII protein using an anti‐human FVIII antibody having negligible cross‐reactivity with canine FVIII. Plasma transgenic FVIII persisted for at least 48 weeks after implantation in the intramedullary cavity. Transgenic FVIII protein levels were low after intramuscular implantation and undetectable after both intravenous infusion and subcutaneous implantation. All plasma samples were negative for anti‐human FVIII antibodies. Plasma concentrations and durability of transgenic FVIII secretion showed no correlation with the therapy index. Thus, the implantation site microenvironment is crucial. The intramedullary microenvironment, but not extramedullary tissues, supported durable engraftment of genetically modified autologous FVIII‐secreting BMSCs.     

针对骨髓移植病患中铁过载的去铁治疗研究进展

骨髓移植是临床上治疗恶性造血系统疾病的常见手段。而铁过载是临床上常见的并发症之一,对病患的造血功能和治疗后恢复有极大的抑制作用。了解铁过载产生的分子或遗传机制能帮助优化去铁化方案,提高去铁化治疗的效率。本文总结了骨髓移植前后铁过载现象发生机制的最新研究进展,并阐述了临床上多种去铁治疗的方案,以期为该类病患铁过载的预防和治疗提供参考。     

自体骨髓干细胞移植联合奥扎格雷对糖尿病足的临床疗效探究

目的探讨自体骨髓干细胞移植联合奥扎格雷对糖尿病足（DF）的临床疗效。 方法选取2017年7月至2018年8月期间于重庆市大渡口区人民医院收治的99例DF患者为研究对象,随机分为奥扎格雷组、移植组与联合组3组各33例。全部患者入院后均给予DF的常规治疗,奥扎格雷组、移植组、联合组分别给予奥扎格雷、自体骨髓干细胞移植、自体骨髓干细胞移植联合奥扎格雷,比较干预前、干预后12周的临床症状体征、DF严重程度、生存质量的变化,以及干预后12周的新生侧支血管的分级情况。定性资料采用χ²检验或Wilcox秩和检验,定量资料组内干预前后比较采用配对t检验,多组比较先采用方差分析,然后采用Tukey检验进行两两比较。采用Pearson相关系数探讨截肢组患者生活质量评分的相关因素。 结果3组患者干预前的基线资料、疼痛、冷感、间歇性跛行的评分、踝肱指数（ABI）、Wagner分级、糖尿病特异性生活质量量表（DSQL）各维度评分与总分比较,差异无统计学意义（P > 0.05）,具有可比性。组内比较,3组干预后的疼痛、冷感、间歇性跛行的评分、DSQL生理功能、心理（精神）因素、社会关系等维度评分与总分均低于干预前,Wagner分级、ABI优于干预前,差异有统计学意义（P < 0.05）。组间比较,联合组干预后的疼痛、冷感、间歇性跛行的评分、DSQL生理功能、心理（精神）因素等维度评分与总分分别为0.83±0.36、0.83±0.31、1.36±0.63、8.9±3.2、7.5±2.5、23.7±9.2,均低于奥扎格雷组的1.13±0.39、1.26±0.59、1.89±0.73、12.5±5.2、10.1±3.1、31.7±8.8及移植组的1.08±0.33、1.11±0.55、1.72±0.60、10.9±3.6、9.3±3.3、28.8± 7.6,差异有统计学意义（F = 5.001、5.598、3.953、2.230、9.610,P均< 0.05）。联合组干预后的ABI为0.55±0.21,高于奥扎格雷组的0.43±0.20及移植组的0.42±0.16,差异有统计学意义（F = 4.051,P < 0.05）。联合组干预后的社会关系维度评分、Wagner分级为1级的比例分别为5.0±2.1、81.8%,高于奥扎格雷组的6.3±2.3、54.5%,差异有统计学意义（F = 3.953,χ²= 6.983,P均 < 0.05）。观察组干预后的新生侧支血管分级优于奥扎格雷组,差异有统计学意义（P < 0.05）。 结论自体骨髓干细胞移植联合奥扎格雷能缓解DF患者的临床症状,促进溃疡愈合,促进移植术后的血管新生,提高生存质量,值得临床推广应用。     

Uncovering the emergence of HSCs in the human fetal bone marrow by single-cell RNA-seq analysis

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Monosomy 7 in donor cell-derived leukemia after bone marrow transplantation for severe aplastic anemia: Report of a new case and review of the literature

Monosomy 7 arises as a recurrent chromosome aberration in donor cell leukemia after hematopoietic stem cell transplantation. We report a new case of donor cell leukemia with monosomy 7 following HLA-identical allogenic bone marrow transplantation for severe aplastic anemia (SAA). The male patient received a bone marrow graft from his sister, and monosomy 7 was detected only in the XX donor cells, 34 months after transplantation. The patient’s bone marrow microenvironment may have played a role in the leukemic transformation of the donor hematopoietic cells.     

Modulation of one of three murine bone marrow stromal cell lines to adipose cells by serum and insulin

Adipose cells have been recognized as an integral component of the bone marrow hematopoietic microenvironment in vivo and as an essential cell type required for in vitro maintenance of stem cells. Four stromal cell lines obtained from the adherent cell population of murine bone marrow cultures have been enriched and purified by multiple trypsinizations. We noted that these cell lines exhibited an accumulation of vacuoles of lipid, the extent of which varied be-tween cell lines in response to a change from medium containing 10% fetal calf serum to medium containing 20% horse serum. The lipid was lost when the cell lines were transferred back into the medium supplemented with fetal calf serum. In light of the reported lipogenic and antilipolytic effects of insulin on fibroblasts and adipocytes, we investigated the ability of insulin to induce adipocyte transformation of these bone marrow stromal cell populations. Three cell lines were exposed to bovine insulin at concentrations ranging from 10^?9 to 10^?6 M. All three cell lines responded to the insulin by accumulating lipid, but the extent of accumulation and the insulin concentration at which maximum lipid content was attained were population specific. One cell line (MC₁) responded fully at physiological levels of insulin (10^?9 M), whereas the other two showed lipid accumulation only at pharmacological concentrations. The initial growth of MC₁ was inhibited in the presence of 10^?9 M insulin which is compatible with the observed differentiation to adipocytes. The growth of MC₃ was unaltered in the presence of physiological concentrations of insulin, whereas that of MC₄ was accelerated. Grafts of organ cultures of the cell lines under the kidney capsule of syngeneic mice developed specific characteristics rep-resentative of the different cell lines. In particular, the majority of the grafts of MC₁ consisted primarily of fat cells which were not observed in the grafts of MC₃ and MC₄. These data strongly suggest that these cell lines comprise cells with different potentialities and that the MC₁ line represents a preadipocyte stromal cell of bone marrow.     

The role of busulfan in bone marrow transplantation

High-dose busulfan is an important component in many conditioning protocols for hematopoietic stem cell transplantation (HSCT) or bone marrow transplantation (BMT) in both adults and children. During the past 12y several studies have reported the wide inter-invidual variability in busulfan disposition. Age, disease status, hepatic function, circadian rhythmicity, drug interactions and bioavailability, were identified as factors contributing to the high inter-individual variability found in busulfan disposition. Traditionally, a standard busulfan dose of 4mg/kg/d for four days is used in most BMT/HSCT protocols. Many investigations have pointed out the pharmacodynamic relationship between a high busulfan systemic exposure and the occurrence of BMT related toxicity including hepatic veno-occlusive disease (VOD), interstitial pneumonia and alopecia in adult patients. However, studies in young patients have shown a high rate of graft failure and subsequently relapse which most probably is due to the low systemic exposure despite the standard dose schedule. In children and infants VOD was not observed with the standard doses. Increasing interest for the drug and new modification strategies for children led to higher rate of VOD and CNS toxicity when busulfans was administered according to the body surface area. More pharmacodynamic studies are required to establish the relation between the systemic exposure to busulfan and the therapeutic efficacy, especially in young children undergoing BMT or HSCT. In the present time an accurate and effective busulfan plasma level monitoring combined with dose adjustment based on the known pharmacological parameters may improve the clinical outcome for patients undergoing BMT.