人羊膜上皮细胞在大鼠受损肝组织中分化为肝细胞

 摘要：目的 探讨人羊膜上皮细胞在大鼠损伤肝原位植活及向肝细胞分化。方法 采用胰蛋白酶消化法从羊膜组织中分离人羊膜上皮细胞（hAECs）,采用流式细胞术和免疫荧光染色进行表型分析和细胞鉴定。采用腹腔注射D-氨基半乳糖建立大鼠肝损伤模型,随机分为hAECs移植组和对照组,每组20只。造模后24h用微量注射器于肝左、中、右叶3点分别移植L-DMEM 悬浮的hAECs悬液50μL（约1×106个细胞）,对照组注射等量L-DMEM。于移植后48h、1周、2周和4周处死各实验组5只大鼠,取肝脏制备冰冻切片,采用免疫荧光双染色检查hAECs在受损肝原位的植活、分布及其向肝细胞分化的标志物表达。结果：⑴ FCM分析和免疫荧光染色结果显示,所分离的hAECs表达CD29、CD166及CK19,几乎不表达CD44、CD80、CD86、HLA-DR及波形蛋白;⑵ 免疫荧光双染色结果显示,hAECs移植后1周主要定植于肝小叶且表达AFP,至2周表达CK18,至4周表达Alb。结论：hAECs在大鼠受损肝组织中能被植活且可分化为肝细胞,提示hAECs移植在临床肝病的治疗方面可能具有潜在应用价值。     

人羊膜间充质干细胞原位移植治疗大鼠脑梗死北大核心

背景:前期实验研究发现,移植人羊膜间充质干细胞能有效改善脑梗死大鼠的神经损伤症状。目的:观察移植人羊膜间充质干细胞在大鼠脑梗死区域的存活、定植和分化情况。方法:将60只SD大鼠随机分为3组,实验组、模型组采用线栓法制作大脑中动脉闭塞模型,假手术组只结扎血管,不插入线栓;造模后1 d,实验组于受损纹状体和皮质两点原位植入10μL第3代人羊膜间充质干细胞悬液(含细胞2×106/只),模型组与假手术组于相同部位注射等体积PBS。移植后1周连续监测体质量并进行神经缺损严重程度评分;移植后2周,TTC染色观察脑梗死面积,苏木精-伊红染色观察脑组织病理学变化,免疫荧光染色检测移植大鼠大脑神经细胞标志物神经元特异性核蛋白的表达。结果与结论:(1)体质量与神经缺损严重程度评分:与假手术组比较,模型组、实验组体质量呈下降趋势,实验组降低少于模型组,但差异无显著性意义;模型组、实验组神经功能缺损评分随时间呈逐渐降低趋势,但实验组评分明显低于模型组;(2)脑梗死面积:模型组大脑皮质出现局灶性缺血坏死且范围较大,与模型组比较,实验组缺血灶面积明显缩小;(3)脑组织病理:实验组梗死病灶范围、神经细胞及炎细胞浸润均少于模型组;(4)免疫荧光染色:移植后1周,实验组脑组织可见较多的移植人羊膜间充质干细胞,2周后可见移植的人羊膜间充质干细胞向神经样细胞分化;(5)结果表明:人羊膜间充质干细胞移植可在大鼠脑梗死区域定植、存活,且在原位能分化为神经样细胞。     

尾静脉移植羊膜间充质干细胞治疗大鼠脑缺血再灌注损伤

背景：羊膜间充质干细胞是一种理想的再生医学领域的种子细胞来源。 目的：探讨尾静脉移植羊膜间充质干细胞对脑缺血损伤的作用。 方法：线栓法制备大鼠大脑中动脉梗死模型,缺血2 h后进行再灌注。造模后24 h通过尾静脉移植1.0×105个人羊膜间充质干细胞,于造模后2,4周完成神经功能评分后取材。以未移植的模型大鼠为对照。 结果与结论：脑损伤后,大鼠出现神经功能评分明显增高,羊膜间充质干细胞移植1周,大鼠的神经功能评分显著降低(P < 0.05),移植2,4周时,神经功能进一步改善。免疫荧光染色显示,移植羊膜间充质干细胞的大鼠脑组织中可见较多发绿色荧光的BrdU阳性细胞,主要位于缺血区周围、皮质下和侧脑室。说明尾静脉移植羊膜间充质干细胞可迁移至大鼠脑缺血区,改善大鼠的神经功能。     

人脐血间充质干细胞移植改善肝硬化大鼠的肝功能

背景：人脐血间充质干细胞移植治疗肝硬化的可行性及机制有待深入探讨。 目的：观察经门静脉移植人脐血间充质干细胞对肝硬化大鼠肝功能及组织病理学改变的影响。 方法：采用四氯化碳法制备肝硬化大鼠模型,造模成功后,细胞移植组经门静脉注射1 mL BrdU标记的人脐血间充质干细胞(5×106个),模型组注射等体积的PBS;以经门静脉移植1 mL人脐血间充质干细胞的正常大鼠作为对照。细胞移植后4周,取大鼠尾静脉血及肝脏组织进行检测。 结果与结论：细胞移植后4周,与模型组比较,细胞移植组大鼠血清谷丙转氨酶、谷草转氨酶、总胆红素明显降低,而白蛋白明显升高(P < 0.01);肝细胞炎性坏死、脂肪变及肝纤维化程度明显改善(P < 0.05或P < 0.01)。免疫组化及免疫荧光染色显示细胞移植组和对照组大鼠肝组织中均有人脐血间充质干细胞的定植,但细胞移植组BrdU阳性细胞数目明显多于对照组。RT-PCR检测结果显示,细胞移植组大鼠肝组织表达人源性细胞角蛋白18和白蛋白mRNA,而模型组未见。可见人脐血间充质干细胞移植可在一定程度上改善肝硬化大鼠的肝功能及病理损伤,其机制可能与移植细胞在肝硬化大鼠肝内归巢定植并向肝样细胞分化有关。     

人羊膜上皮细胞静脉移植治疗大鼠心肌梗死

背景：人羊膜上皮细胞在体外适当诱导条件下可分化为心肌样细胞,可望成为细胞心肌成形术的种子细胞,但在心肌梗死原位是否能分化成心肌细胞值得探讨。 目的：探讨人羊膜上皮细胞移植在心肌梗死原位的分化及对心肌梗死后心室重构和心功能的影响。 方法：用胰酶消化分离人羊膜上皮细胞,行流式细胞仪检测和免疫组化染色以鉴定其表型特征。结扎SD大鼠左冠状动脉前降支以建立心肌梗死模型,实验分为人羊膜上皮细胞移植组、模型组及假手术组,人羊膜上皮细胞移植组于造模后1周经舌下静脉移植Brdu标记的人羊膜上皮细胞。移植后1,4,6周采用超声心动图检查心功能变化,应用苏木精-伊红和Masson染色观察心肌重构的变化,以免疫荧光双染色法检测人羊膜上皮细胞在心肌梗死区的植活与分化。 结果与结论：①所分离的人羊膜上皮细胞表达CD29、CD166、CD73和CK19,不表达CD44、CD34、CD45、CD80、CD86和HLA-DR。②人羊膜上皮细胞移植后6周,心肌梗死区仍可见Brdu标记的阳性细胞,表达心肌特异蛋白连接蛋白43、α-辅肌动蛋白和结蛋白。③移植组大鼠左心室纤维化程度明显低于模型组。④移植组大鼠射血分数、左室短轴缩短率显著高于模型组(P < 0.01);舒张期左室前壁厚度和收缩期左室前壁厚度也显著大于模型组(P < 0.05)。提示人羊膜上皮细胞在心肌梗死原位可分化为心肌细胞,可减缓心室重构并改善心脏功能。     

体外诱导骨髓间充质干细胞向胆管上皮样细胞分化

背景：肝外胆管和胆囊上皮细胞的分离、纯化相对比较容易,但是胆管上皮细胞在体外易失去增殖能力,难以提供基础研究所需的细胞量,限制了胆管修复等基础研究的进程。虽然骨髓间充质干细胞可以转化为肝细胞,但是尚无体外培养骨髓间充质干细胞分化为胆管上皮细胞的报道。 目的：探讨体外诱导骨髓间充质干细胞分化为胆管上皮细胞的可行性。 方法：采取全骨髓贴壁筛选法体外分离并纯化大鼠骨髓间充质干细胞后,在第3代骨髓间充质干细胞培养基中加入肝细胞生长因子和表皮生长因子,倒置显微镜下观察骨髓间充质干细胞的形态学变化,免疫荧光检测不同时间CK19的表达情况。 结果与结论：在肝细胞生长因子和表皮生长因子的诱导下,骨髓间充质干细胞由梭形逐渐变为多边形、三角形;免疫荧光检查显示诱导第4周细胞膜开始表达CK19,诱导第6周CK19表达率明显提高。结果表明在两种细胞因子联合诱导下骨髓间充质干细胞能够转化为胆管上皮样细胞,从而为骨髓间充质干细胞修复损伤胆管提供了一个新思路。     

骨髓间充质干细胞在肝部分切除模型小鼠体内向肝细胞分化

以含20%胎牛血清的DM EM低糖培养基,原代细胞直接贴壁培养,48 h后换液继续培养,分离BALB/C小鼠的骨髓间充质干细胞,该细胞分为CD44 CD29 与CD44-CD29 两群。将第5代骨髓间充质干细胞注入部分肝切除小鼠肝右叶,术后5 d和14 d分别处死动物,测体重、肝重与肝功,制备肝组织芯片,原位杂交和免疫荧光同步检测Y染色体与肝细胞标记(白蛋白或CK 18),并作图像叠加。发现移植组小鼠在移植后5 d与14 d在注射肝叶与非注射肝叶内皆可检出大量同时表达Y染色体与白蛋白及Y染色体与CK 18的细胞。术后14 d,移植组肝重与肝脏器指数高于模型组。表明骨髓间充质干细胞能在有再生需求的小鼠体内向肝细胞分化并参与再生。     

羊膜上皮细胞和羊膜间充质干细胞构建组织工程皮肤

背景：由于人胎盘来源的间充质干细胞具有多方面的优点,近年来已成为干细胞研究的热点。 目的：分析鉴定羊膜间充质干细胞和羊膜上皮细胞的生物学特性,探讨其作为皮肤种子细胞在三维气液培养构建组织工程皮肤中的应用情况。 方法：用胰酶胶原酶多步消化法获取羊膜间充质干细胞和羊膜上皮细胞,通过流式细胞术、反转录-聚合酶链反应和免疫荧光染色技术,鉴定两种细胞的表面分子标记、干细胞特性、与皮肤角质形成细胞的相似性,并利用两种细胞为种子细胞以鼠Ⅰ型胶原为基质进行三维气液培养。 结果与结论：①流式细胞术检测体外培养羊膜间充质干细胞和羊膜上皮细胞均高表达CD90、CD73、CD105,不表达造血干细胞标志CD34以及MHC-Ⅱ类分子HLA-DR。②反转录-聚合酶链反应检测到羊膜间充质干细胞表达干细胞特性基因CMCY和NANOG,羊膜上皮细胞表达干细胞特性基因CMCY和 KLF4,两种细胞均有干细胞特性。③反转录-聚合酶链反应检测羊膜间充质干细胞表达皮肤角质形成细胞特性基因K19、β1-integrin、K8,羊膜上皮细胞表达K19、β1-integrin、K5、K8,免疫荧光染色见羊膜上皮细胞表达与角质形成细胞增殖相关的的特性蛋白K14,说明羊膜上皮细胞与皮肤角质形成细胞更具相似性, 在特定条件下更易于分化为皮肤角质形成细胞。④利用两种细胞成功构建组织工程皮肤,苏木精-伊红染色切片显示其具有一定的皮肤结构,且羊膜上皮细胞发生了初步分化。以上结果说明羊膜间充质干细胞与羊膜上皮细胞通过三维培养构建人皮肤组织是可行的。     

体外诱导羊膜来源间充质干细胞分化为血管内皮细胞

背景：羊膜来源间充质干细胞植入机体不同类型组织后是否可以分化为相应组织靶细胞呢？ 目的：检测血管内皮细胞生长因子在体外诱导人羊膜间充质干细胞分化为血管内皮细胞的可行性。 方法：分离培养羊膜间充质干细胞,鉴定其表面抗原表达,用含体积分数2%胎牛血清以及50 μg/L血管内皮生长因子的条件培养基诱导,诱导后细胞通过内皮细胞标志物血管内皮生长因子受体2以及v-WF染色鉴定。 结果与结论：羊膜间充质干细胞表面抗原CD29、CD44、CD105阳性,CD34、CD45、CD106以及HLA-DR阴性。诱导后细胞形态明显改变,内皮细胞标志物血管内皮细胞生长因子受体2以及v-WF染色结果阳性。提示羊膜间充质干细胞在体外具有分化为血管内皮细胞的能力。     

毛囊干细胞对坐骨神经损伤修复的影响

背景：毛囊干细胞具有多分化潜能,可分化成神经细胞,极有希望成为治疗周围神经损伤的种子细胞。 目的：观察毛囊干细胞对坐骨神经损伤修复的影响。 方法：体外分离培养SD大鼠乳鼠胡须处的毛囊干细胞,经鉴定备用。36只SD大鼠随机分为实验组和对照组,建立坐骨神经损伤模型后,实验组于坐骨神经损伤处的上方注入浓度约10⁶ L^-1的毛囊干细胞50 μL,对照组注射等量的磷酸盐缓冲液。 结果与结论：各组坐骨神经功能指数均随观察时间进行性增加,其中实验组大鼠神经功能恢复早于对照组;免疫组织化学检测移植后的毛囊干细胞大量存活并分化成神经细胞。结果提示毛囊干细胞能够有效的促进损伤的坐骨神经修复。     

CD24-positive cells from normal adult mouse liver are hepatocyte progenitor cells

The identification of specific cell surface markers that can be used to isolate liver progenitor cells will greatly facilitate experimentation to determine the role of these cells in liver regeneration and their potential for therapeutic transplantation. Previously, the cell surface marker, CD24, was observed to be expressed on undifferentiated bipotential mouse embryonic liver stem cells and 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced oval cells. Here, we describe the isolation and characterization of a rare, primary, nonhematopoietic, CD24+ progenitor cell population from normal, untreated mouse liver. By immunohistochemistry, CD24-expressing cells in normal adult mouse liver were colocalized with CK19-positive cholangiocytes. This nonhematopoietic (CD45-, Ter119-) CD24+ cell population isolated by flow cytometry represented 0.04% of liver cells and expressed several markers of liver progenitor/oval cells. The immunophenotype of nonhematopoietic CD24+ cells was CD133, Dlk, and Sca-1 high, but c-Kit, Thy-1, and CD34 low. The CD24+ cells had increased expression of CK19, epithelial cell adhesion molecule, Sox 9, and FN14 compared with the unsorted cells. Upon transplantation of nonhematopoietic CD24+ cells under the sub-capsule of the livers of Fah knockout mice, cells differentiated into mature functional hepatocytes. Analysis of X and Y chromosome complements were used to determine whether or not fusion of the engrafted cells with the recipient hepatocytes occurred. No cells were found that contained XXXY or any other combination of donor and host sex chromosomes as would be expected if cell fusion had occurred. These results suggested that CD24 can be used as a cell surface marker for isolation of hepatocyte progenitor cells from normal adult liver that are able to differentiate into hepatocytes.     

异种肝前体细胞移植治疗急性肝损伤大鼠

背景：成体肝前体细胞可在受体肝脏内定植并分化为肝细胞。不过,异种肝前体细胞移植能否促进急性肝损伤的恢复,脾脏微环境能否促进移植物的存活和向肝细胞分化,尚没有研究。 目的：评价异种肝前体细胞移植治疗急性肝损伤的作用;监测移植肝前体细胞在大鼠脾脏实质内的定植及向肝细胞的分化。 方法：体外培养雄性小鼠来源的肝前体细胞系肝上皮样前体细胞。通过CCl4腹腔注射联合2/3肝切除构建急性肝损伤大鼠模型,进行肝上皮样前体细胞脾脏移植。在肝切除后1,5,14和21 d,苏木精-伊红染色观察肝脏病理改变,全自动生化分析仪监测血清转氨酶变化,PCR反应检测脾脏组织Y染色体特异性序列Sry,脾脏CK-19和Alb免疫组织化学追踪移植肝上皮样前体细胞的植入和肝细胞分化。 结果与结论：肝上皮样前体细胞可在体外长期培养,保持增殖能力和双向分化潜能。肝上皮样前体细胞脾脏移植后,肝损伤大鼠肝细胞肿胀明显减轻,丙氨酸转氨酶和天门冬氨酸转氨酶下降更明显。移植后1,5,14和21 d,脾脏DNA中均能检测到Sry序列。在整个实验期间CK-19阳性细胞在大鼠脾脏实质内始终存在。Alb阳性细胞在移植后5 d在脾脏实质中出现,随后阳性细胞数逐渐增多。实验表明,移植肝前体细胞能在大鼠脾脏实质中植入,并分化为肝细胞,能有效促进CCl4腹腔注射联合2/3肝切除诱导的大鼠急性肝损伤的修复过程。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

胎儿骨髓源性亚全能干细胞分离培养及诱导肝细胞分化研究

目的研究分离胎儿骨髓源性亚全能干细胞及体内、外向肝细胞分化的潜能。方法利用密度梯度离心结合免疫磁珠方法分离胎儿骨髓源性亚全能干细胞，体外培养鉴定，诱导分化。制备肝功能衰竭重度联合免疫缺陷小鼠（severe combined immunodeficiency，SCID）模型。肝原位输注106左右CD105^＋细胞，对照组分别输注106左右的CD105^-细胞或同等体积的培养液。移植细胞后2d、7d、1个月、3个月时分别取3只鼠的血清及组织标本行肝功能和病理学、免疫组织化学检测。结果免疫磁珠筛选后的免疫细胞化学检测CD105呈弱阳性表达；细胞在对数生长期的倍增时间为30h左右；约传10代后进入衰退期；SCID鼠移植细胞3个月后用鼠抗人白蛋白抗体检测小鼠肝脏中的人白蛋白，可见有点状或小灶状表达。结论来源于胎儿骨髓的亚全能干细胞可以在体外及肝脏微环境下转化为肝细胞样细胞。因此进一步深入研究组织微环境在细胞转化中的机制有十分重要的意义，将为开发诱导胎儿骨髓亚全能干细胞的多向分化潜能提供理论依据。     

Hepatic stem cells: a review

The existence of a liver stem cell population has only gained credence recently, following the results of animal experiments. These cells are thought to reside in the terminal bile ductules (canals of Hering). Hepatocyte division is responsible for liver regeneration after most causes of injury. However, stem cells may contribute to hepatocyte regeneration, or even take over this role if the liver injury is severe and associated with an impairment of hepatocyte proliferation as in cirrhosis or submassive/massive necrosis, due to drugs, toxins or viruses. "Oval" cells are the descendants of the stem cells and are found in the portal and periportal regions in experimental animals within days of the liver injury. These cells proliferate to form narrow ductules, which may stain positively for biliary cytokeratins CK 19, and radiate out into the damaged parenchyma. Both in vitro and in vivo animal studies now suggest that oval cells can differentiate into bile ductular cells or hepatocytes to allow repopulation of the injured liver. As the oval cells differentiate into hepatocytes they may show positive staining for pyruvate kinase isoenzyme L-PK, albumin and alpha-fetoprotein. There is also growing evidence that bone marrow stem cells may contribute to liver regeneration. The possible involvement of hepatic stem cells in the development of dysplastic nodules, hepatocellular carcinoma and cholangiocarcinoma has been suggested but remains highly controversial. Oval cell isolation and culture techniques, together with stem cell transplantation strategies, may in the future provide novel treatments for individuals with inherited and acquired hepatic disorders.     

Functional regeneration of irradiated salivary glands with human amniotic epithelial cells transplantation

This study aimed to investigate the functional restoration of radiation-damaged salivary gland with human amniotic epithelial cells (hAECs) transplantation by intra-glandular injection. hAECs were isolated from the amnion tissues. After primary culture, the phenotype of hAECs of the second passage was identified by flow cytometry (FCM) and immunocytochemical staining. Then, hAECs were intra-glandularly injected into the irradiated glands of mice. At different time points after transplantation, the glands were collected for hematoxylin-eosin (HE) staining and immunofluorescence staining, and the saliva flow rate was also determined. Results showed these cells were positive for CD29, CD73 and CK19 and negative for CD44, CD34, CD45 and CD71. The transplanted hAECs in the recipient glands could differentiate into acinar-like cells and resulted in morphological and functional restoration of salivary gland.     

胚胎来源肝干细胞肝内移植后在小鼠体内的分布及分化

BACKGROUND:As many factors can lead to liver injury, we attempt to use the “therapeutic liver regeneration” technology in clinical treatment of liver diseases by promoting liver regeneration. OBJECTIVE:To investigate distribution and differentiation of embryonic liver stem cells in mice after intrahepatic transplantation via a transplantation approach. METHODS:Liver injury models were prepared in 20 BALB/c mice, and then randomly equivalently assigned into two groups: 70% partial hepatectomy with intrahepatic transplantation with 1×10⁵ embryonic liver stem cells in control group; therapeutic liver regeneration model plus intrahepatic transplantation with 1x10⁵ embryonic liver stem cells in observation group. At 1 and 2 weeks after cell transplantation, the liver parenchyma of mice was observed. And at 2 weeks, both of the two groups underwent confocal immunofluorescence assay. Besides, blood samples of mouse tail vein were collected to detect levels of serum albumin. RESULTS AND CONCLUSION:At 1 week after cell transplantation, in the liver parenchyma, green fluorescence was sparsely distributed in the two groups, and the distribution density had no significant difference between the two groups; at 2 weeks after cell transplantation, hepatic cord-like structures appeared in the liver parenchyma of two groups, and the green fluorescence distribution in the control group was limited, but significantly expanded in the observation group. At 2 weeks after cell transplantation, positive albumin expression in the liver parenchyma was significantly higher in the observation group than in the control group, and there was no significant difference in levels of serum albumin between two groups (P > 0.05). To conclude, after transplantation of embryonic liver stem cells in the therapeutic liver regeneration model mice hepatocytes can be effectively integrated into the host hepatic plate, differentiate in the liver, and partially trigger the function of hepatocytes.