体外诱导胰腺干细胞向胰岛样细胞团的分化***☆

背景：目前由于胰岛来源匮乏,使得胰岛细胞移植治疗糖尿病无法满足临床需求,故体外将胰腺干细胞诱导分化为胰岛成为研究焦点。 目的：于体外将小鼠胰腺干细胞诱导成胰岛样细胞团并对其进行相关检测,探寻一种胰腺干细胞体外诱导分化成胰岛及鉴定的技术和方法。 方法：体外获得纯化的小鼠胰腺干细胞,采用联合诱导剂对其进行成胰岛方向的诱导分化,并对诱导形成的胰岛样细胞团进行形态学观察、双硫腙染色、RT-PCR和Western blot检测。 结果与结论：实验通过细胞形态学和细胞生长特性的观察以及免疫细胞化学染色证实体外成功获得了小鼠胰腺干细胞,采用联合诱导剂将其诱导成胰岛样结构,呈球形,以较细长的蒂部与瓶底连接,双硫腙染色将其染成铁红色。RT-PCR和Western blot 法可分别检测到胰岛样细胞团的胰岛素mRNA和胰岛素蛋白。结果证实小鼠胰腺干细胞可体外诱导分化成含β细胞的胰岛样细胞团。 关键词：胰腺干细胞;诱导;胰岛样细胞团;干细胞培养;小鼠 doi:10.3969/j.issn.1673-8225.2012.10.020     

犬骨髓间充质干细胞分离纯化和成骨诱导分化:Ficoll液密度梯度离心法体外分离的可行性

背景:目前骨髓间充质干细胞较经典的分离方法是Percoll密度梯度离心法,以去除血细胞成分,但该法操作较为复杂,分离犬骨髓时需要配制密度,且离心次数较多,对细胞损伤大。目的:拟建立可靠、高纯度的犬骨髓间充质干细胞体外分离纯化方法,并观察其在体外扩增、成骨诱导分化的能力。方法:于犬髂后上棘抽取骨髓液10mL,肝素抗凝,Hanks液稀释后,加入1.077g/mL Ficoll液3mL,2000r/min离心20min,吸取有核细胞形成白色云雾状的分层界面,用含胎牛血清的DMEM离心2遍,按12×104/cm2密度接种,于37℃、体积分数为5%的CO2培养箱内培养。细胞传代后,加入含地塞米松、β-磷酸甘油钠、L-2-磷酸抗坏血酸的DMEM成骨条件培养液进行诱导。免疫细胞化学染色和免疫荧光染色检测成骨细胞特征性分泌蛋白骨钙素、骨桥蛋白的表达,以及Ⅰ型胶原的表达,并进行碱性磷酸酶染色与茜素红染色。结果与结论:1.077g/mLFicoll液密度梯度离心法分离所得的有核细胞层相对于Percoll液分层明显,可获得纯度较高的骨髓间充质干细胞,接种细胞生长良好,平均倍增时间为24h。犬骨髓间充质干细胞体外成骨诱导培养后,骨钙素、骨桥蛋白、Ⅰ型胶原均呈阳性表达,碱性磷酸酶染色后细胞胞浆呈蓝绿色,茜素红染色后细胞外基质中出现散在的红色结节,可在体外定向分化为成骨细胞。     

Isolation,culture and osteogenic induction of rabbit bone marrow mesenchymal stem cells

背景：骨髓间充质干细胞具有多向分化潜能,且可大量体外扩增培养,是重要的组织工程种子细胞。但尚无统一的体外培养及定向诱导方法。 目的：探讨体外定向诱导兔骨髓间充质干细胞分化为成骨细胞的可行性。 方法：应用密度梯度离心法从兔四肢骨中分离纯化间充质干细胞,应用密度为1.073 g/mL的Percoll分离液,3 000 r/min×30 min离心,区别于相关报道的Ficoll分离液,2 000-2 500 r/min×(20-30) min离心以及全骨髓培养法体外扩增至第3代,分别在普通培养基(对照组)和成骨诱导培养基(实验组)中培养。 结果与结论：成功获得大量高纯度骨髓间充质干细胞。经成骨诱导后,实验组骨钙素含量明显高于对照组(P < 0.05)。实验组碱性磷酸酶和钙结节染色阳性,对照组均阴性。结果表明使用密度梯度离心法可成功建立兔骨髓间充质干细胞的分离培养体系,骨髓间充质干细胞可定向诱导为成骨细胞。     

脐血间充质干细胞的分离培养及生物学特性

背景：脐血富含干细胞,刺激后进入细胞周期的速度以及自泌生长因子的能力均强于骨髓及外周血干细胞。 目的：建立一种分离纯化、培养扩增脐血间充质干细胞的方法,并观察体外培养脐血间充质干细胞的生物学特性。 方法：密度梯度离心,贴壁培养和消化时间控制相结合,分离纯化脐血间充质干细胞。观察细胞形态,绘制细胞生长曲线,应用流式细胞仪测定细胞周期,以免疫组织化学法(SP法)测定CD29,CD44,CD34。采用体积分数20%马血清诱导脐血间充质干细胞分化为脂肪细胞,以油红O染色鉴定;0.1 μmol/L地塞米松,10 mmol/L β-甘油磷酸钠和50 μmol/L抗坏血酸诱导脐血间充质干细胞分化为成骨细胞,以碱性磷酸酶染色鉴定。 结果与结论：分离获得了高纯度贴壁生长的间充质干细胞,间充质干细胞呈梭形,细胞传代稳定,在体外连续传代培养9代,未发生形态学改变,无衰老征象。第3代间充质干细胞体外可以分化为脂肪细胞和成骨细胞。提示采用淋巴细胞分离液密度梯度离心,贴壁培养和消化时间控制相结合,可以获得纯度较高的脐血间充质干细胞,脐血间充质干细胞体外增殖和传代能力强。     

全骨髓贴壁法培养兔骨髓间充质干细胞体外定向成骨诱导分化及鉴定

背景：流式细胞仪分离法和免疫磁珠分离法对细胞活性影响较大,密度梯度离心法虽然能够获得纯度高的单核细胞,但由于多次离心可造成细胞的大量流失且对细胞活性有一定的影响使其应用值得商榷。 目的：采用全骨髓贴壁法分离兔骨髓间充质干细胞进行成骨诱导分化及鉴定。 方法：采用全骨髓贴壁法体外分离培养兔骨髓间充质干细胞,倒置显微镜下观察细胞形态学特征。在成骨诱导剂作用下,通过碱性磷酸酶染色试剂盒行碱性磷酸酶染色,Ⅰ型胶原免疫细胞化学染色,Von Kossa法及茜素红进行矿化结节染色以及电镜下检测兔骨髓间充质干细胞成骨诱导后的形态结构。 结果与结论：经诱导后细胞出现与成骨细胞相似的形态学特征,碱性磷酸酶染色阳性,Ⅰ型胶原免疫细胞化学染色,Von-Kossa法及茜素红矿化结节染色阳性。表明经成骨诱导剂诱导后全骨髓贴壁法体外分离纯化培养的兔骨髓间充质干细胞能向成骨细胞方向分化增殖。     

骨髓间充质干细胞的分离培养及其定向诱导成骨与软骨表型的实验研究

本实验旨在建立一种体外分离纯化、培养扩增大鼠骨髓间充质干细胞的方法，探讨成年大鼠骨髓间充质干细胞(MSCs)的生物学特性及其作为组织工程种子细胞的可行性。方法：用密度梯度离心结合贴壁培养法分离纯化Wistar大鼠骨髓间充质干细胞。取第二代成年大鼠骨髓间充质干细胞，一部分进行形态学观察(倒置显微镜、HE染色、电镜)，     

兔骨髓间充质干细胞的生物学特征及原代培养

背景：兔来源的骨髓间充质干细胞是具有较强的体外增殖和多系统分化潜能的成体干细胞,在组织工程及生物治疗领域蕴藏着巨大的潜能。 目的：体外培养扩增、鉴定兔骨髓间充质干细胞,观察骨髓间充质干细胞的生物学特征。 方法：无菌条件下抽取兔骨髓,分别运用全骨髓贴壁法和Percoll密度梯度离心法体外分离骨髓间充质干细胞,利用差速贴壁原理对细胞进行纯化扩增。在显微镜下观察细胞形态特征及生长规律,流式细胞技术检测细胞表面抗原标记物的表达。 结果与结论：兔骨髓间充质干细胞贴壁时间短,增殖快,经过细胞传代后能够获得进一步纯化的细胞,杂质细胞减少。原代细胞形态即呈现三角形、长梭形、纺锤形的贴壁细胞特征。第 5代骨髓间充质干细胞呈典型的极性漩涡状生长,形态单一均匀,不具有表达造血前体细胞表面标志抗原CD34和白细胞表面标志抗原CD45的表面标记物功能,但是具有能够表达出整合素家族的成员 CD29 及黏附分子CD44的特点。说明经全骨髓贴壁法和Percoll密度梯度离心法体体外分离培养的细胞在形态学、细胞表面标志物表达和多向分化能力方面具有干细胞生物学特性,经流式细胞分析鉴定为兔骨髓间充质干细胞。 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     

人脐血间充质干细胞培养及其生物学特性的研究

目的建立人脐血间充质干细胞体外分离培养的最佳条件,并观察其生物学特性。方法在无菌条件下抽取人脐血,用密度梯度离心的方法获得脐血单个核细胞,接种含10%胎牛血清的IMDM培养基中。对单个核细胞行贴壁培养后,进行细胞形态学观察,细胞生长、细胞周期分析及细胞凋亡检测,免疫细胞化学鉴定。结果采用Percoll(1.073g/ml)分离的脐血间充质干细胞(mesenchymal stem cells,MSCs)大小较为均匀,呈梭形或星形的上皮样细胞,传代培养后的细胞体积较大,成纤维样细胞逐渐增多。细胞生长曲线测定表明接种后第5d细胞进入指数增生期,至第9d进入平台期;流式细胞术证明G2+S期细胞为14.8%;免疫细胞化学染色结果表明42.0%细胞为CD45阳性。结论体外分离培养脐血间充质干细胞生长稳定,可作为组织工程的种子细胞。     

胰腺干细胞体外培养扩增的方法

背景：胰腺干细胞在体外培养时极易分化,很难获得足够数量的胰腺干细胞。 目的：探讨一种简便易行的胰腺干细胞体外扩增培养方法。 方法：分离新生昆明小鼠胰腺,原代培养三四天,成纤维细胞中出现呈集落生长的胰腺干细胞后,以0.02%EDTA消减成纤维细胞的数量,降低其比例后继续培养,待细胞铺满培养瓶底的80%时,重复三四次,逐渐提高胰腺干细胞的数量。检测胰腺干细胞特异性标志Nestin。尼克酰胺诱导胰腺干细胞分化;双硫腙染色对胰岛样细胞团进行检测。 结果与结论：消减胰腺成纤维细胞的数量及比例后,胰腺干细胞可持续表现出活跃的分裂增殖能力,胰腺干细胞的数量显著增加;细胞保持球形、单个大核、细胞质折光性强、表达(Nestin)。扩增的胰腺干细胞,以尼克酰胺诱导后分化为胰岛样细胞团,双硫腙染色阳性。提示,减少共培养中成纤维细胞的比例和数量,有利于胰腺干细胞的增殖,获得较多数量的胰腺干细胞。扩增后的胰腺干细胞仍保持未分化状态,在适当的体外诱导条件下能分化为胰岛样结构,具有一定的分化潜能。     

小鼠睾丸间质细胞体外原代培养方法的建立

背景：组织块培养睾丸生殖细胞对污染不容易控制,胰蛋白酶消化接种培养睾丸生殖细胞可能损伤细胞。 目的：建立一种切实可行的小鼠睾丸间质细胞体外原代培养方法。 方法：小鼠睾丸间质细胞的分离采用胶原酶消化法,纯化采用Percoll等密度梯度离心法,活率鉴定采用锥虫蓝拒染法,纯度鉴定采用3β-羟基固醇脱氢酶染色方法。 结果与结论：小鼠睾丸间质细胞纯度达可达90%以上;体外培养的细胞形态完整、增殖速度快、贴壁生长状态良好。说明实验成功建立了小鼠睾丸间质细胞的体外原代培养模型。     

Pancreatic development and stem cell-based regenerative medicine

After the gut endoderm is formed, subsequent permissive induction signals from the notochord allows the pancreas to emerge and growout from a specific site of the embryonic gut epithelium. The first pancreas-specific gene, pdx1, is expressed around this stage. Interaction between pancreatic epithelium and the surrounding mesenchyme allows the pancreas bud to further grow and differentiate to form ductal, exocrine or endocrine lineages. Several lines of evidence from gene knockout mice and cell lineage studies suggest that a common pancreas stem cell first gives rise to exocrine and endocrine progenitor cells. The endocrine progenitor then give rise to four different endocrine cells: alpha, beta, delta, and PP cells, although it is not known how and when these cells arise. We have focused our studies on the understanding of endodermal induction and organogenesis of the pancreas. We specifically aimed at the isolation of pancreatic stem cells and the development of functional pancreatic endocrine beta cells in culture. For this aim, we used ES cells as a model system. Here, I review the literature on the development and regeneration of the pancreas. Some recent results on growing pancreatic cells from ES (embryonic stem) cells.     

Continuous-Perifusion tissue culture of fetal and adult pancreas of the lizard Anolis carolinensis

The differentiation of the fetal saurian pancreas in continuousperifusion tissue culture (CPTC) was examined. Splenic pancreases from 24-day postoviposition fetuses of the green anole, Anolis carolinensis, were grown for 8 to 31 days by CPTC following successful preliminary studies with adult pancreas. Adult anolian endocrine pancreas was maintained for up to 7 days by CPTC. The pancreatic explants were examined morphologically by light and electron micros-copy. The functional integrity of the endocrine cells was evaluated by measuring hormone levels of the explants and in the basal medium and by determining the kinetics of hormone release. The pancreatic endocrine cells from fetal and adult anoles were functionally and morphologically intact after CPTC. The exocrine pancreas was not maintained during culture. This study demonstrates for the first time the growth of the reptilian endocrine pancreas in culture.     

人胰腺混合性导管-内分泌癌细胞系的建立

目的 建立胰腺混合性导管－内分泌癌细胞系。方法 从一轩性患者胰头切除的肿瘤组织取材,切割为细小的组织块接种于裸鼠皮下,经过裸鼠的两次过渡后,再取第二裸鼠皮下的肿瘤组织,切割为非常小的组织块,用含有１０％胎牛血清的培养基接种至培养瓶进行体外培养。结果 该细胞系目前已传至５５代。这一细胞系同时具有内、外分泌胰腺癌的形态特征,并得到了免疫组化标记和组织化学染色的证实。电镜下,部分细胞内含有神经分泌颗粒。     

Pancreatic stem cells

Conclusions Available evidence strongly suggests that different cell types in pancreas are capable of undergoing transdifferentiation and dedifferentiation. Evidence also strongly supports the existence of stem cells in both the exocrine and endocrine pancreas. In the rat copper dificiency model, dormant stem cells present in the ductal and ductular system can be stimulated to proliferate and they have been shown to clearly differentiate into hepatocytes, a cell type not normally present in pancreas. Putative stem cells derived from the pancreas of rats after prolonged copper deficiency, can be easily grown in culture, but there is need to identify appropriate signals and defined culture conditions that can direct the in a reproducible fashion to differentiate into a specific cell type such as β-cells or liver cells. When these specific signaling molecules are identified pancreatic stem cells will be a source of an unlimited supply of self-renewable cells for transplantation. Although, the existence of pancreatic stem cells is being increasingly accepted and their multidirectional differentiation potential is recognized, their role, if any, in pancreatic cancer development remains to be clarified and investigated.     

人皮下脂肪干细胞的成骨、成脂分化诱导及鉴定

背景：脂肪干细胞是从脂肪组织中分离得到的一种具有多向分化潜能的间充质干细胞,在组织工程中比骨髓间充质干细胞具有更多优势,是当今的研究热点之一。 目的：在体外建立一种分离纯化人皮下脂肪来源脂肪干细胞的方法,进行体外培养扩增及诱导其向成骨、成脂细胞分化。 方法：通过密度梯度离心和贴壁筛选法相结合,对人脂肪干细胞进行分离、体外培养及扩增。倒置显微镜下观察人脂肪干细胞的细胞形态和生长特性。选取第2代及第5代细胞,用CCK-8法检测细胞活性,绘制细胞生长曲线,用流式细胞仪检测细胞表面抗原标记。选取第5代细胞,分别进行成脂及成骨诱导分化,以确定其多向分化潜能。 结果与结论：①采用密度梯度离心和贴壁培养相结合方法,可成功从人脂肪组织中获得纯度较高的人脂肪干细胞。②人脂肪干细胞经历了生长滞缓期、对数增殖期和生长平台期,符合正常细胞的生长规律,且其生长具有对数生长期,其倍增时间较短。③人脂肪干细胞表达干细胞表面抗原标记,具有低免疫原性,且具有成脂成骨多向分化潜能。④DAPI是一种简单、有效的标记人脂肪干细胞的方法,DAPI不损伤细胞活性,对细胞标记率高。 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     

Fetal and neonatal rat pancreas in organ culture age-related effects of corticosterone on the acinar cell component

Fetal rat pancreas (ages 16 to 22 days postcoitum) and neonatal pancreas (4 days postnatal) were grown in organ culture for four days. The medium consisted of chick embryo extract and rooster serum either with or without the addition of corticosterone (3 × 10^?5 M). Acinar cell differentiation was assessed using quantitative light microscopic linear scanning of tissue sections and enzymatic analysis of amylase in the culture media and in the explants. In the younger fetal tissue of 16 and 18 days postcoitum exocrine differentiation continued in vitro. The effect of corticosterone was an enhancement of the degree of in vitro differentiation. Even with corticosterone, however, the degree of differentiation in vitro was less than that observed during a similar period in vivo. In differentiated pancreas (20- and 22-day fetal and 4-day neonatal) the acinar pancreas degenerated under control conditions and a selective growth of the endocrine pancreas was observed. The addition of corticosterone to the media resulted in a maintenance of the differentiated state of the acini except in 22-day fetal tissue in which the acini were not preserved. The differences between these results and the work of other investigators and the possible in vivo role of adreno corticosteroids in exocrine pancreatic differentiation is discussed.     

Isolation and subfractionation of human peripheral blood mononuclear cells (PBMC) by density gradient centrifugation on Percoll

The use of Percoll for isolation and subfractionation of PBMC and T-lymphocytes by discontinuous and continuous density gradient centrifugation is described: PBMC were isolated from human peripheral blood by discontinuous density gradient centrifugation on Percoll. The use of Percoll instead of Ficoll-Isopaque has the advantage that Percoll, in contrast to Ficoll-Isopaque, does not alter the density of monocytes. Therefore, a better separation of lymphocytes and monocytes was achieved after subsequent continuous density gradient centrifugation on Percoll. E-RFC were isolated by discontinuous density gradient centrifugation after a first low speed centrifugation step banding lymphocytes and SRBC on a Percoll-Ficoll cushion, and a subsequent high speed centrifugation step separating high density rosettes and SRBC from low density non-E-RFC. The advantage of this procedure is the short time of performance and that there is no need to resuspend the lymphocyte/SRBC pellet. PBMC, nph.PBMC T-lymphocytes were further subfractionated by continuous density gradient centrifugation on Percoll. The method described here resulted in a good separation of lymphocytes and monocytes. However, to obtain lymphocyte fractions with minute numbers of contaminating monocytes, a depletion of monocytes prior to further subfractionation of the lymphocytes by continuous density gradient centrifugation is recommended. A marker analysis of T-lymphocytes subfractionated by continuous density gradient centrifugation on Percoll shows that high density T-lymphocytes are enriched in ANAE positive lymphocytes of type 1 and depleted of ANAE positive lymphocytes of type 2. Low density T-lymphocytes are enriched in ANAE type 2 cells and depleted of ANAE type 1 cells. On the other hand, no considerable differences were found when analyzing the T-cells from different fractions for differentiation antigens by means of monoclonal antibodies (anti Lyt 3, OKT4, and OKT8). The results may indicate that subfractionation of T-lymphocytes by continuous density gradient centrifugation on Percoll provided T-cells in different functional states rather than T-cells of distinct subclasses.