小鼠骨髓来源Flk-1+间充质干细胞分离制备与生物学特点

背景：骨髓间充质干细胞具有广泛的应用前途,其三系分化的能力和免疫诱导特性使其具有再生医学的应用前景。 目的：从小鼠骨髓中研究分离制备Flk-1⁺间充质干细胞的新方法,检测了这类细胞的生物特性。 方法：以小鼠骨髓为研究对象,分离单个核细胞,体外培养并 扩增原始间充质干细胞,检测它们的细胞周期、表型和多系分化的能力。 结果与结论：小鼠来源的骨髓来源的原始间充质干细胞呈成纤维样生长,大部分细胞处于G₀/G₁期,并且高表达Flk1,CD13,CD29,CD44,小鼠骨髓来源Flk-1⁺间充质干细胞在光镜下均呈成纤维样或多角型贴壁生长,在体外相应的诱导液环境中均可以向三系分化。提示小鼠骨髓来源Flk-1⁺间充质干细胞具有多向分化潜能。     

骨髓间充质干细胞移植治疗大鼠溃疡性结肠炎

背景：近年已有干细胞移植修复慢性肠炎受损组织的报道,但其治疗机制尚不明确。 目的：观察移植骨髓间充质干细胞在溃疡性结肠炎大鼠结肠的分布及分化情况,及对大鼠结肠黏膜的修复作用。 方法：取经鉴定的第3代大鼠骨髓间充质干细胞1×10⁶个,应用Hoechst 33342进行荧光标记,并将其经尾静脉移植入溃疡性结肠炎大鼠体内,分别于移植后3,7,14 d取材。 结果与结论：骨髓间充质干细胞移植后 3 d,大鼠结肠即可见荧光标记的细胞,移植后14 d,大鼠结肠荧光标记细胞仍较多,此时可见部分标记细胞表达细胞角蛋白。同时骨髓间充质干细胞移植后14 d,溃疡性结肠炎大鼠结肠黏膜白细胞介素10表达增高,肿瘤坏死因子α表达降低, 结肠黏膜的病理损伤明显好转。说明移植的骨髓间充质干细胞可迁移至结肠溃疡部位并分化为上皮细胞,同时可通过调节炎性因子的表达促进溃疡性结肠炎大鼠结肠黏膜损伤的修复。     

外源性硫化氢预处理骨髓间充质干细胞移植治疗大鼠心肌梗死

背景：骨髓间充质干细胞移植可促进心肌修复,治疗心肌梗死,但移植后细胞存活率低等原因制约了其应用与发展。 目的：探讨硫化氢预处理对骨髓间充质干细胞移植治疗心肌梗死效果的影响。 方法：从(100±20) g SD大鼠中分离培养骨髓间充质干细胞,第4代时按实验分组处理,移植前2 h给予DAPI标记。将50只体质量(200±20) g雄性SD大鼠分为心肌梗死组和假手术组,心肌梗死组结扎冠状动脉前降支建立心肌梗死模型,假手术组只穿线不结扎,每组10只。模型建立24 h后,分组在梗死心肌周围选择4个点,分别注射生理盐水、骨髓间充质干细胞、硫化氢预处理骨髓间充质干细胞及硫化氢。细胞移植4周后用超声心动图检测心功能指标,Masson染色测定梗死交界区胶原。 结果与结论：生理盐水组大鼠心肌纤维化严重,梗死区域无心肌组织再生;外源性硫化氢处理后的骨髓间充质干细胞移植组比单用硫化氢或者骨髓间充质干细胞组心肌纤维化程度轻,胶原组织中可见较多心肌细胞再生。硫化氢预处理骨髓间充质干细胞组左室射血分数、左室短轴缩短率显著高于硫化氢组及骨髓间充质干细胞组(P < 0.05)。提示硫化氢预处理骨髓间充质干细胞可提高移植后的细胞存活率,改善梗死后心功能,其作用优于单用硫化氢或者骨髓间充质干细胞。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;组织工程全文链接：     

骨髓间充质干细胞移植治疗大鼠急性放射性肺损伤

背景:针对放射性肺损伤,临床上除了糖皮质激素及抗生素等对症处理外,尚缺乏有效的治疗手段。近年来研究表明,骨髓间充质干细胞表现出强大的组织修复能力。目的:观察骨髓间充质干细胞对大鼠放射性肺损伤的治疗作用,并初步探讨其作用机制。方法:体外分离、培养并鉴定雄性SD大鼠骨髓间充质干细胞。应用直线加速器照射60只雌性SD大鼠胸部,建立大鼠放射性肺损伤模型,随机分为骨髓间充质干细胞治疗组和生理盐水对照组。骨髓间充质干细胞治疗组经大鼠尾静脉输注骨髓间充质干细胞2×109L-1,生理盐水对照组注射等量生理盐水,分别于照射后1,2,4,6周时进行相关指标检测。结果与结论:照射后第1,2,4周时,骨髓间充质干细胞治疗组大鼠肺系数明显低于生理盐水对照组(P0.05)。镜下见骨髓间充质干细胞治疗组大鼠肺组织炎症渗出较少,肺泡、肺泡壁结构基本完整,纤维化程度等均明显轻于生理盐水对照组。照射2周时骨髓间充质干细胞治疗组血清转化生长因子β1、羟脯氨酸水平显著低于生理盐水对照组(P0.05)。照射2,4,6周时骨髓间充质干细胞治疗组肺组织超氧化物歧化酶活力显著高于生理盐水对照组(P0.05),照射4,6周时骨髓间充质干细胞治疗组丙二醛含量显著低于生理盐水对照组(P0.05)。照射6周时骨髓间充质干细胞治疗组的肺表面活性物质B表达显著高于生理盐水对照组。PCR方法检测肺、肝脏、胰腺、肾脏等器官组织均有不同程度的Sry基因表达,尤以肺显著。结果表明骨髓间充质干细胞可以迁移到放射性损伤的肺组织,促进放射性肺损伤组织的修复,其治疗机制可能与抑制炎症反应、抗氧化、减轻肺组织纤维化等有关。     

骨髓间充质干细胞治疗肾缺血再灌注损伤的旁分泌机制

背景：骨髓间充质干细胞已用于肾缺血再灌注损伤修复的实验动物研究。 目的：探讨骨髓间充质干细胞治疗肾缺血再灌注损伤的旁分泌机制。 方法：体外培养、纯化并体外DAPI标记大鼠骨髓间充质干细胞,经下腔静脉移植入肾缺血再灌注损伤模型大鼠体内,观察骨髓间充质干细胞对肾缺血再灌注损伤肾功能的保护作用以及在受体鼠体内的迁移情况,并应用免疫组织化学法检测骨髓间充质干细胞治疗后第2天缺血肾脏组织中血管内皮生长因子、肿瘤坏死因子α细胞因子的表达。 结果与结论：与注射生理盐水的对照组比较,细胞移植组大鼠血清肌酐和尿素氮水平在移植后第1、2天明显降低(P < 0.05),但细胞移植组移植后第1、2天肾组织中均未见DAPI阳性细胞;第3、4天则逐渐可见DAPI阳性细胞。免疫组织化学染色结果显示,与对照组相比,移植后第2天肾组织中可见较多血管内皮生长因子阳性细胞,而肾组织中肿瘤坏死因子α阳性细胞明显减少。结果显示旁分泌机制参与了骨髓间充质干细胞治疗肾缺血再灌注损伤。     

糖尿病与正常大鼠骨髓间充质干细胞移植治疗心肌梗死的比较

背景：目前国内外在干细胞移植治疗心肌梗死的研究中,大多采用正常或者年轻的骨髓间充质干细胞作为移植细胞来源。 目的：比较糖尿病和正常大鼠骨髓间充质干细胞移植治疗心肌梗死的疗效差别。 方法：无菌条件下获取正常大鼠及糖尿病大鼠的骨髓间充质干细胞,建立大鼠心肌梗死模型并随机分为3组,分别于心肌梗死病灶区注射100 μL含有105-106个F2代正常大鼠或糖尿病大鼠来源骨髓间充质干细胞的细胞混悬液,空白对照组注射100 μL含体积分数20%胎牛血清的DMEM。移植后1个月行苏木精-伊红染色检测各组梗死区域心肌组织形态的变化;通过免疫组化方法检测Bcl-2的表达。 结果与结论：通过对细胞形态观察及流式细胞术鉴定,大鼠股骨骨髓贴壁培养可获取纯度较高的骨髓间充质干细胞,绘制细胞生长曲线结果显示正常大鼠骨髓间充质干细胞较糖尿病大鼠骨髓间充质干细胞生长快。移植后1个月,正常大鼠干细胞移植组梗死区域心肌组织形态较糖尿病大鼠干细胞移植组及空白对照组明显改善,梗死区域心肌组织Bcl-2的表达也高于其他2组。证实正常大鼠来源骨髓间充质干细胞较糖尿病大鼠骨髓间充质干细胞生长明显加快,且糖尿病使骨髓干细胞移植治疗心肌梗死的疗效降低。     

间充质干细胞的细胞表型及免疫学研究进展

间充质干细胞具有多分化潜能,参与构成骨髓的微环境,分泌大量细胞因子支持造血。最近的研究显示间充质干细胞免疫表型呈现动态的表达;同种异体细胞移植免疫排斥由于移植抗原差异而引起,但同种异体间充质干细胞却具有免疫抑制作用。综述了其可能的机制及作为组织工程种子细胞的间充质干细胞具有独特的生物学特性。     

骨髓间充质干细胞移植修复慢性阻塞性肺病气道损伤

背景：间充质干细胞能够分化为肺实质细胞并参与肺部损伤的修复,为间充质干细胞在慢性阻塞性肺病中的应用提供了新的方法。 目的：观察骨髓间充质干细胞移植对大鼠慢性阻塞性肺病气道损伤的修复作用。 方法：将24只雌性大鼠随机分为4组：①骨髓间充质干细胞移植组(12只)：采用熏烟+脂多糖法建立慢性阻塞性肺病大鼠模型,于造模后第1天经尾静脉输注1 mL CM-Dil标记的骨髓间充质干细胞。②骨髓间充质干细胞对照组(4只)：在第1天和第14天经气管注入生理盐水300 μL,经尾静脉输注1 mL CM-Dil标记的骨髓间充质干细胞。③慢性阻塞性肺病模型组(4只)：采用熏烟+脂多糖法建立慢性阻塞性肺病大鼠模型,于造模后第1天经尾静脉输注1 mL PBS。④健康对照组(4只)：在第1天和第14天经气管注入生理盐水300 μL,经尾静脉输注1 mL PBS。在各组大鼠注射骨髓间充质干细胞后的第1,7,15,30天,进行病理学和血清学检测。 结果与结论：①苏木精-伊红染色结果显示：骨髓间充质干细胞移植组大鼠肺气肿和气道病变较慢性阻塞性肺病模型组轻,但较骨髓间充质干细胞对照组和健康对照组严重。②移植后第1天,骨髓间充质干细胞移植组外周血白细胞总数和中性粒细胞比例高于骨髓间充质干细胞对照组和健康对照组(P < 0.05),随着时间延长,骨髓间充质干细胞移植组白细胞总数和中性粒细胞比例不断降低。③移植后第1天,骨髓间充质干细胞移植组外周血白细胞介素10水平低于骨髓间充质干细胞对照组和健康对照组(P < 0.05),肿瘤坏死因子α和粒细胞集落刺激因子水平高于骨髓间充质干细胞对照组和健康对照组(P < 0.05)。随着移植时间的延长,骨髓间充质干细胞移植组外周血肿瘤坏死因子α水平不断降低,白细胞介素10水平不断升高,粒细胞集落刺激因子水平先升高再降低,其中第7天水平最高。④CM-Dil染色联合免疫组化检测提示,部分 CM-Dil阳性细胞同时CC16表达阳性。结果显示经尾静脉注射骨髓间充质干细胞能够改善慢性阻塞性肺病大鼠的肺部病理损伤,通过分化为气管黏膜上皮细胞以及参与免疫调节对气道进行修复。 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     

骨髓间充质干细胞修复损伤脊髓的实验及临床应用短期随访

背景：骨髓间充质干细胞治疗脊髓损伤的研究已经逐渐由动物实验过渡到临床,但其作用机制还不完全清楚。 目的：观察骨髓间充质干细胞移植对脊髓损伤大鼠脊髓功能的修复作用,并通过临床应用观察短期疗效。 方法：采用改良Allen's打击法造成Wistar大鼠脊髓损伤模型,将体外分离培养的骨髓间充质干细胞分别经尾静脉及损伤局部移植,应用改良Tarlov评分评定大鼠行为学变化,在光镜下对损伤脊髓病理切片进行对比分析。对5例脊髓损伤患者通过损伤原位注射、腰穿、静脉输注的方式行人自体骨髓间充质干细胞移植,并行神经功能及生活能力评定。 结果与结论：治疗后15 d,骨髓间充质干细胞尾静脉及损伤局部移植组大鼠运动功能评分较模型对照组显著提高;移植后7,15,30 d,脊髓病理切片显示骨髓间充质干细胞尾静脉及损伤局部移植组大鼠较模型对照组有显著恢复。临床患者骨髓间充质干细胞移植后半年神经功能及生活能力均有改善。     

缺氧诱导骨髓间充质干细胞条件培养基体外修复辐射损伤小肠上皮细胞变化

背景：间充质干细胞条件培养基含有丰富的间充质干细胞旁分泌物质,被认为是干细胞移植理想的替代方案。然而,正常状态的间充质干细胞条件培养基可能由于旁分泌活性不足,常无法有效修复损伤组织。 目的：观察缺氧诱导的骨髓间充质干细胞条件培养基(MSC-CMHyp)对大鼠小肠隐窝上皮IEC-6细胞辐射损伤后增殖和凋亡的影响,并进一步探讨其修复小肠上皮细胞的旁分泌机制。 方法：IEC-6细胞接受10 Gy X射线照射后分别加入MSC-CMHyp、正常培养的骨髓间充质干细胞条件培养基(MSC-CMNor组)及DMEM-F12培养基(DMEM-F12组)培养。 结果与结论：锥虫蓝染色、流式细胞仪、Western blot检测结果显示,与DMEM-F12组相比,MSC-CMHyp组IEC-6细胞存活数和增殖率明显增加(P < 0.05),凋亡率和凋亡相关因子Caspases-3/8表达明显下降(P < 0.05),而MSC-CMNor组的各项指标与DMEM-F12组比较差异无显著性意义(P > 0.05)。EILSA检测结果显示,与MSC-CMNor相比,MSC-CMHyp中血管内皮生长因子、碱性成纤维细胞生长因子、胰岛素样生长因子1、和白细胞介素10的含量明显升高(P < 0.05)。结果表明,缺氧诱导的骨髓间充质干细胞条件培养基中细胞因子含量明显升高,显著促进辐射损伤IEC-6细胞的增殖,同时下调细胞凋亡信号,从而进一步促进损伤细胞的修复。 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     

骨髓间充质干细胞移植对木瓜蛋白酶和［60Co］照射所致大鼠肺气肿的作用

目的：研究骨髓间充质干细胞（MSCs）移植对木瓜蛋白酶和［⁶⁰Co］照射所致肺气肿的影响及其机制。方法：雌性大鼠随机分为对照组、肺气肿组和肺气肿+MSCs移植组。将大鼠进行［⁶⁰Co］照射，在气管内滴入木瓜蛋白酶建立雌性大鼠肺气肿模型，然后将培养的雄性大鼠MSCs经尾静脉注射到雌性肺气肿大鼠。观察移植后大鼠肺组织的病理学变化；通过PCR和Y染色体荧光原位杂交（Y-FISH）示踪雄性大鼠MSCs在雌性肺气肿大鼠肺组织内的植入情况；用Y-FISH和肺泡表面活性物质蛋白C（SP-C）免疫荧光显色方法检测雄性大鼠MSCs在受体肺组织内是否分化为II型肺泡上皮细胞。结果：肺气肿组、肺气肿+MSCs移植组大鼠均出现肺气肿改变，但后者较前者的肺气肿明显减轻，2组之间的肺泡平均内衬间隔、平均肺泡面积和单位面积肺泡数均有显著差异；PCR结果显示肺气肿+MSCs移植组的大鼠肺脏基因组DNA中可以扩增出位于Y染色体的Sry基因片段；Y-FISH显示肺气肿+MSCs移植组的雌性大鼠肺组织中有Y染色体阳性的细胞，并且部分Y染色体阳性细胞同时表达SP-C。结论：MSCs移植能够减轻木瓜蛋白酶和［⁶⁰Co］照射所致的肺气肿，这可能与移植的MSCs在受体肺组织中的植入和分化为II型肺泡上皮细胞有关。     

Mesenchymal stem cells contribute to the renal repair of acute tubular epithelial injury

Acute renal failure (ARF) is a common disease with high morbidity and mortality. Recovery from ARF is dependent on the replacement of necrotic tubular cells with functional tubular epithelium. Recent advancement in developmental biology led to the discovery of immature mesenchymal stem cells (MSCs) in bone marrow and several established organs and to the definition of their potential in the recovery from tissue injury. We investigated the effect of MSCs infusion on the recovery from ARF induced by intramuscle injection of glycerol in C57/BL6 mice. In this model, ARF is associated with an extensive necrosis of tubular epithelial cells due to myoglobin- and hemoglobin-induced injury. MSCs were obtained from bone marrow of transgenic mice expressing green fluorescent protein (GFP). MSC GFP-positive cells (MSC-GFP(+)) injected intravenously homed to the kidney of mice with glycerol-induced ARF but not to the kidney of normal mice. MSC-GFP(+) localized in the context of the tubular epithelial lining and expressed cytokeratin, indicating that MSCs engrafted in the damaged kidney, differentiated into tubular epithelial cells and promoted the recovery of morphological and functional alterations. Moreover, MSCs enhanced tubular proliferation as detected by the increased number of proliferating cell nuclear antigen (PCNA) positive cells. A significant contribution of the engrafted MSCs in the regeneration of tubular epithelial cells was shown by the presence of a consistent number of GFP(+) tubular cells 21 days after the induction of injury. In conclusion, these results indicated a tropism of MSCs for the injured kidney and a potential contribution of these cells to tubular regeneration and to the recovery from ARF.     

Flk-1+Sca-1- mesenchymal stem cells: functional characteristics in vitro and regenerative capacity in vivo

Objectives: Mesenchymal stem cells (MSCs) represent a powerful tool in regenerative medicine because of their differentiation and migration capacities. We aimed to investigate the possibility of Flk-1⁺Sca-1^- mesenchymal stem cells (Flk-1⁺Sca-1^- MSCs) transplantation to repair erectile function in patients suffering from diabetes mellitus (DM)-associated erectile dysfunction (ED). Methods: In this study, we isolated Flk-1⁺Sca-1^- MSCs from bone marrow (bMSCs). Then, newborn male rats were intraperitoneally injected with 5-ethynyl-2-deoxyuridine for the purpose of tracking endogenous Flk-1⁺Sca-1^- MSCs. Eight weeks later, 8 of these rats were randomly chosen to serve as normal control (N group). The remaining rats were injected intraperitoneally with 60 mg/kg of streptozotocin (STZ) to induce DM. Eight of these rats were randomly chosen to serve as DM control (DM group) while another 8 rats were subject to Flk-1⁺Sca-1^- MSCs treatment (DM+MSC group). All rats were evaluated for erectile function by intracavernous pressure (ICP) measurement. Afterward, their penile tissues were examined by histology. Results: Flk-1⁺Sca-1^- MSCs could differentiate into skeletal muscle cells and endothelial cells in vivo and in vitro. Engrafted Flk-1⁺Sca-1^- MSCs were shown to home to injured muscle, participate in myofibers repair and could partially reconstitute the sarcolemmal expression of myocardin and ameliorate the level of related specific pathological markers. Conclusion: Flk-1⁺Sca-1^- MSCs could be used in the treatment erectile function in diabetes mellitus associated erectile dysfunction by promoting regeneration of nNOS-positive nerves, endothelium, and smooth muscle in the penis.     

HGF/c-Met Signaling Mediated Mesenchymal Stem Cell-induced Liver Recovery in Intestinal Ischemia Reperfusion Model

Purpose: Liver injury triggered by intestinal ischemia-reperfusion (IIR) usually presage multiorgan dysfunction and death in patients. Recent studies suggest mesenchymal stem cells (MSCs) possess a protective potential against organ damage. Since relative evidence is insufficient and the mechanism is not well understood, we investigated the effect of hepatocyte growth factor c-Met signaling (HGF/c-Met) on recruitment of MSCs and subsequent protection against liver injury triggered by IIR in a rat model.Methods: IIR models were built as rats were subjected to 75 min of superior mesenteric artery occlusion and subsequent 4 h reperfusion. Either of pure MSCs and MSCs pretreated with HGF or SU11274 (c-Met inhibitor) were injected into rat models. Biochemical and pathologic alterations of liver in IIR model were measured to evaluate the therapeutic effect of MSCs and drug treatment. Concurrently, the effect of HGF and SU11274 on c-Met and phosphorylated Met expression in MSCs and MSCs migration were assessed in in vitro experiment.Results: IIR-induced liver injury was manifested by significant increase in serum ALT, AST and HGF levels as well as pathological change. MSCs with highly c-Met expression ameliorated the increase of serum transaminase levels and hepatic histopathological change, while SU11274 weaken these effects. HGF upregulated c-Met and phosphorylated Met expression in MSCs and enhanced its liver protection effect. Transwell assays demonstrated HGF promoted MSCs migration, which was blocked by SU11274.Conclusions: HGF/c-Met signaling pathway plays an essential role in the homing of MSCs towards injured liver triggered by intestinal ischemia-reperfusion, and then mediates MSC-induced liver repair.     

Exposure of a tendon extracellular matrix to synovial fluid triggers endogenous and engrafted cell death: A mechanism for failed healing of intrathecal tendon injuries

Aim: The purpose of this study was to investigate the effect of normal synovial fluid (SF) on exposed endogenous tendon-derived cells (TDCs) and engrafted mesenchymal stem cells (MSCs) within the tendon extracellular matrix. Methods: Explants from equine superficial digital flexor (extra-synovial) and deep digital flexor tendons (DDFTs) from the compressed, intra-synovial and the tensile, extra-synovial regions were cultured in allogeneic or autologous SF-media. Human hamstring explants were cultured in allogeneic SF. Explant viability was assessed by staining. Proliferation of equine monolayer MSCs and TDCs in SF-media and co-culture with DDFT explants was determined by alamarblue®. Non-viable Native Tendon matrices (NNTs) were re-populated with MSCs or TDCs and cultured in SF-media. Immunohistochemical staining of tendon sections for the apoptotic proteins caspase-3, ?8, and ?9 was performed. Results: Contact with autologous or allogeneic SF resulted in rapid death of resident tenocytes in equine and human tendon. SF did not affect the viability of equine epitenon cells, or of MSCs and TDCs in the monolayer or indirect explant co-culture. MSCs and TDCs, engrafted into NNTs, died when cultured in SF. Caspase-3, ?8, and ?9 expression was the greatest in SDFT explants exposed to allogeneic SF. Conclusions: The efficacy of cells administered intra-synovially for tendon lesion repair is likely to be limited, since once incorporated into the matrix, cells become vlnerable to the adverse effects of SF. These observations could account for the poor success rate of intra-synovial tendon healing following damage to the epitenon and contact with SF, common with most soft tissue intra-synovial pathologies.     

移植骨髓间充质干细胞减轻脂多糖诱导的小鼠急性肺损伤

目的 观察移植骨髓间充质干细胞 （MSCs） 对脂多糖 （LPS） 诱导小鼠急性肺损伤 （ALI）的治疗修复作用。方法 全骨髓培养法培养小鼠骨髓MSCs;细胞免疫化学染色鉴定MSCs特异表面标记;小鼠咽后壁吸入LPS制造小鼠肺损伤;尾静脉注射引入MSCs;称重计算肺水肿指数;肺组织切片HE染色观察组织病理改变;ELISA检测肺泡灌洗液和肺组织匀浆中IL-1β含量;Brdu（5-Bromo-2-Deoxyuridine）标记供体MSCs,免疫组织化学染色及双染色观察移植细胞的迁移和分化状态。结果 培养的MSCs细胞表面标记CD44阳性,而造血系表面标记CD34阴性。吸入LPS后,小鼠出现典型的肺损伤病理改变,肺水肿指数和肺组织匀浆IL-1β含量明显增加。标记的MSCs移植入同种异体的肺损伤小鼠,其肺部出现标记的MSCs,并表达上皮细胞标志抗原-细胞角蛋白（CK）。治疗后小鼠的肺水肿指数和肺组织匀浆IL-1β含量下降。结论 外源性MSCs移植到肺损伤小鼠体内,可迁移至肺损伤部位,并表达上皮细胞标志;减轻肺水肿程度,减少炎症因子释放。     

Enhancing epithelial engraftment of rat mesenchymal stem cells restores epithelial barrier integrity

The cellular origin, in vivo function and fate of donor bone marrow‐derived cells residing in the recipient intestinal epithelial cells, pericryptal myofibroblasts or endothelial cells remain obscure. Although ‘immunoprivileged’ mesenchymal stem cells (MSCs) are prime candidates for cell‐ and gene‐based therapy, their precise role in colitis remains largely undetermined. Using a dextran sulphate sodium (DSS) colitis with busulphan (BU)‐induced hypoplastic marrow model, we examined the therapeutic effects of MSC transplantation, focusing on the role of MSCs as both cell providers and immunomodulators. Donor‐derived MSCs were detected by eGFP immunofluorescence and fluorescence in situ hybridization for Y‐chromosome (Y‐FISH) analysis. Western blot analysis of apical‐most tight junction proteins was performed with antibodies against claudin‐2, ‐7, ‐8, ‐12, ‐13, ‐15 and ZO‐1. Cytokine and cell cycle profiles were analysed by semi‐quantitative RT‐PCR and flow cytometry. Susceptibility to DSS colitis was significantly increased by co‐existing BU‐induced bone marrow hypoplasia and this increase was significantly reduced by enhancing epithelial engraftment of MSCs, an effect depending on restoring epithelial barrier integrity rather than inhibiting host immune responses. We provide evidence that implicates MSCs in maintaining epithelial barrier function by reassembling apical‐most tight junction proteins, claudins. The therapeutic efficacy of extrinsic MSCs depends on enhancing epithelial engraftment in damaged crypts by busulphan conditioning. Such a role for the MSC‐derived intestinal cells in colitis therapy merits further examination and may offer a promising new treatment for inflammatory bowel disease (IBD). Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Human placental mesenchymal stem cells of fetal origins-alleviated inflammation and fibrosis by attenuating MyD88 signaling in bleomycin-induced pulmonary fibrosis mice

Pulmonary fibrosis is a progressive lung disease that its pathogenic mechanism currently is incompletely understood. Toll-like receptor (TLR) signaling has recently been identified as a regulator of inflammation and pulmonary fibrosis. In addition, mesenchymal stem cells (MSCs) of different origins offer a great promise in treatment of idiopathic pulmonary fibrosis (IPF). However mechanisms of pathogenic roles of TLR signaling and therapeutic effects of MSCs in the IPF remain elusive. In present study, the involvement of TLR signaling and the therapeutic role of MSCs were interrogated in MyD88-deficient mice using human placental MSCs of fetal origins (hfPMSCs). The results showed an alleviated pulmonary inflammation and fibrosis in myeloid differentiation primary response gene 88 (MyD88)-deficient mice treated with bleomycin (BLM), accompanied with a reduced TGF-β signaling and production of pro-fibrotic cytokines, including TNF-α, IL-1β. An exposure of HLF1 lung fibroblasts, A549 epithelial cells and RAW264.7 macrophages to BLM led an increased expression of key components of MyD88 and TGF-β signaling cascades. Of interest, enforced expression and inhibition of MyD88 protein resulted in an enhanced and a reduced TGF-β signaling in above cells in the presence of BLM, respectively. However, the addition of TGF-β1 showed a marginally inhibitory effect on MyD88 signaling in these cells in the absence of BLM. Importantly, the administration of hfPMSCs could significantly attenuate BLM-induced pulmonary fibrosis in mice, along with a reduced hydroxyproline (HYP) deposition, MyD88 and TGF-β signaling activation, and production of pro-fibrotic cytokines. These results may suggest an importance of MyD88/TGF-β signaling axis in the tissue homeostasis and functional integrity of lung in response to injury, which may offer a novel target for treatment of pulmonary fibrosis.     

诱导骨髓间质干细胞分化为角膜上皮样细胞的初步研究

目的: 观察人骨髓间质干细胞（MSCs）移植到兔角膜基质后的分化发育情况，探讨MSCs分化为角膜上皮细胞的可行性。方法: 24只新西兰兔随机分为2组。实验组：将人MSCs接种在保存人羊膜上培养4 d，用5-溴脱氧尿嘧啶（BrdU）标记后移植到兔角膜基质；对照组：采用保存羊膜移植到兔角膜基质。分别于移植后1、2、3、4、6和8周，摘取各组实验眼行组织学和免疫组织化学检查，检查移植到兔角膜基质的MSCs的存活、形态变化以及移植局部的反应等情况；免疫组织化学检测移植到角膜基质的带有BrdU标记的细胞角蛋白K3/12（CK3/CK12）和角蛋白K13（CK13）的表达。结果: MSCs接种到羊膜后能在羊膜上生长，与羊膜共培养4 d后，MSCs贴附羊膜生长迅速，组织学特征无明显改变。羊膜负载MSCs移植到兔角膜基质表面, 术后免疫组织化学检测角膜上皮层CK3/CK12表达阳性， CK13表达阴性，在重建的角膜上皮层可检测到BrdU核阳性细胞并同时表达角膜上皮细胞特异性表面标志蛋白K3/K12，未发生免疫排斥反应，未见异常增殖细胞。结论: 羊膜负载MSCs移植到兔眼表角膜基质后，MSCs能存活、增殖并向角膜上皮样细胞分化。