富血小板纤维蛋白(PRF)诱导骨髓间质干细胞分化成骨细胞的实验研究

目的研究富血小板纤维蛋白在诱导骨髓间质干细胞向成骨细胞转化的作用。方法取7天新西兰大白兔股骨,分离骨髓间质干细胞进行体外培养,在各自的培养条件下分为三组：实验组（不同剂量的PRF组）、空白对照组（MSCS组）和阳性对照组（BMP-2组）。三组细胞的比较采用MTT测定细胞增值率、PNPP法测定碱性磷酸酶的表达、免疫组化标记Ⅰ型胶原蛋白的表达、检测细胞为成骨细胞。结果细胞形态学观察,MSCS分化后,细胞形态从长梭形变成三角形,多角形,立方形;MTT测定细胞增殖显示,随着PRF膜剂量的增加,细胞增殖数量增加,PRF剂量为4,5mL时,与BMP-2组差别不大;ALP活性结果显示,MSCS分化后,ALP活性远高于MSCS细胞。两者差异具有显著统计学意义（t=24.608,p=0.000）;免疫组化标记Ⅰ型胶原结果显示,PRF组分化后的MSCSⅠ型胶原表达显著。结论富血小板纤维蛋白可以诱导骨髓间质干细胞分化为成骨细胞,分化的类成骨细胞具有成骨细胞的特性,可以作为自体材料应用于口腔种植学领域里骨缺的修复。     

The potential of cell fusion for human therapy

As donor organs and tissues for transplantation medicine are scarce, alternative methods for replacing damaged cells or restoring organ function are highly needed. Here, we consider the therapeutic potential of cell fusion. After highlighting the various contexts in which cells are known to fuse during mammalian development, we discuss the implications of the observation that cell fusion can occur with restorative effects following tissue damage or cell transplantation. There are still, however, many challenges facing those who wish to implement cell fusion as a therapeutic tool. These include identifying the best cells to use for reparative fusion, determining the best route of introducing these cells into the desired tissue, discovering methods to increase the incidence of cell fusion, and ensuring the functionality of the resulting fusion products. If these difficulties can be overcome, cell fusion might have therapeutic potential as highlighted by several recent transplantation studies.     

肝脏卵圆细胞诱导分化为胰岛β细胞的研究进展

肝脏卵圆细胞是具有多向分化潜能的干细胞, 在一定的条件下可诱导分化为胰岛β细胞,葡萄糖、细胞外基质、细胞因子和胰岛转录因子等诸多因素均参与分化过程的调控。文章就肝脏卵圆细胞向胰岛β细胞分化的影响因素进行综述。     

肝脏卵圆细胞诱导分化为胰岛β细胞的研究进展

肝脏卵圆细胞是具有多向分化潜能的干细胞, 在一定的条件下可诱导分化为胰岛β细胞,葡萄糖、细胞外基质、细胞因子和胰岛转录因子等诸多因素均参与分化过程的调控。文章就肝脏卵圆细胞向胰岛β细胞分化的影响因素进行综述。     

LX-2与HK-2细胞共培养模型的建立及对其细胞转分化的影响

[目的]建立人肝星状细胞(LX-2)与人肾小管上皮细胞(HK-2)共培养体系的理论模型,研究LX-2对HK-2转分化的影响。[方法]以Transwell小室建立体外LX-2细胞和HK-2细胞间接共培养体系。应用细胞免疫组织化学法检测HK-2细胞平滑肌肌动蛋白(α-SMA)表达;用酶联免疫吸附法(ELISA法)检测各组细胞培养液中转化生长因子-β1(TGF-β1)的含量;逆转录-聚合酶链反应法(RT-PCR法)检测HK-2细胞TβRⅠm RNA、TβRⅡm RNA、Smad2 m RNA、Smad3 m RNA、Smad7 m RNA的表达。[结果]除了空白组,形态学上其他两组均可看到HK-2细胞胞浆染棕黄色,不同数量细胞由立方铺路石样转变为梭形长条状,细胞肥大;HK-2细胞高表达α-SMA(P0.01);HK-2细胞上清液中TGF-β1含量明显高于空白组(P0.01);HK-2细胞TβRⅠ、Smad2、Smad3基因表达明显上调,而TβRⅡ、Smad7基因表达明显下调。[结论]Transwell共培养法可诱导HK-2细胞转分化,其机制可能与TGF-β1/Smad信号通路有关。     

PTEN抑制增生性瘢痕成纤维细胞转分化作用及其机制

目的观察染色体10上缺失的磷酸酶和张力蛋白同源物(phosphatase and tensin homologue deleted on chromosome ten,PTEN)编码蛋白对TGF-β1刺激下瘢痕成纤维细胞转分化的抑制作用及其机制。方法用重组PTEN腺病毒转染体外培养的人瘢痕成纤维细胞,倒置荧光显微镜检测PTEN转染组及空载体转染组绿色荧光蛋白表达;将实验分为对照组、PTEN转染组、空载体转染组、TGF-β1刺激组(给予TGF-β1刺激)、PTEN+TGF-β1组(PTEN基因转染后给予TGF-β1刺激)、空载体+TGF-β1组(空载体转染后给予TGF-β1刺激),RT-PCR和Western blot分别检测对照组、PTEN转染组、空载体转染组中PTEN mRNA和蛋白表达;Western blot检测各组中α-SMA、Akt、p-Akt表达水平。结果 PTEN基因转染瘢痕成纤维细胞36h后可见明显绿色荧光蛋白表达,PTEN转染组PTEN mRNA及蛋白的表达明显升高,与对照组及空载体转染组相比,差异有统计学意义(P<0.05),而p-Akt和α-SMA的表达明显下降(P<0.05);TGF-β1组α-SMA表达较对照组明显升高,同时伴有p-Akt表达上升,与对照组、PTEN转染组、PTEN+TGF-β1组相比,差异均有统计学意义(P<0.01);空载体转染组与对照组相比,p-Akt、α-SMA蛋白表达差异均无统计学意义(P>0.05);空载体+TGF-β1组与TGF-β1刺激组相比,p-Akt、α-SMA蛋白表达差异均无统计学意义(P>0.05)。各组细胞的Akt表达差异均无统计学意义(P>0.05)。结论 TGF-β1可促进PI3K/Akt通路活化,使瘢痕成纤维细胞α-SMA表达升高,促进其转分化;空载体转染对p-Akt、α-SMA的表达无明显影响,高表达PTEN可使瘢痕成纤维细胞α-SMA的表达明显降低,并且可拮抗TGF-β1对瘢痕成纤维细胞的转分化作用,其机制可能是抑制PI3K/Akt通路活化。     

补阳还五汤通过小窝蛋白1调控Shh信号通路促进脑缺血后星形胶质细胞转分化

目的 基于小窝蛋白1(caveolin-1,Cav1)/音猬因子(sonic hedgehog,Shh)信号通路探讨补阳还五汤对脑缺血后星形胶质细胞转分化的作用机制。方法 雄性C57BL/6小鼠随机分为假手术组、模型组及补阳还五汤低、中、高剂量(9.25、18.50、39.00 g/kg)组和丁苯酞(54 mg/kg)组,除假手术组外,其余各组采用大脑中动脉栓塞(middle cerebral artery occlusion,MCAO)法复制脑缺血模型,给予药物干预21 d后,采用神经行为学评分、苏木素-伊红染色及免疫组化评估补阳还五汤疗效。随后将雄性野生(WT)小鼠及Cav1^-/-(KO)小鼠分别随机分为假手术组、模型组和补阳还五汤(18.5 g/kg)组,造模前7 d予以脑内注射GFAP-EGFP腺相关病毒,采用MCAO法制备脑缺血模型,给予药物干预21 d。采用免疫荧光检测缺血侧皮质区星形胶质细胞转分化情况,Western blotting法检测缺血侧皮质区Shh、平滑同源物(smootened,Smo)及神经胶质瘤关联癌基因同源物1(glioma ass...     

The mammary microenvironment alters the differentiation repertoire of neural stem cells

A fundamental issue in stem cell biology is whether adult somatic stem cells are capable of accessing alternate tissue sites and continue functioning as stem cells in the new microenvironment. To address this issue relative to neurogenic stem cells in the mouse mammary gland microenvironment, we mixed wild-type mammary epithelial cells (MECs) with bona fide neural stem cells (NSCs) isolated from WAP-Cre/Rosa26R mice and inoculated them into cleared fat pads of immunocompromised females. Hosts were bred 6–8 weeks later and examined postinvolution. This allowed for mammary tissue growth, transient activation of the WAP-Cre gene, recombination, and constitutive expression of LacZ. The NSCs and their progeny contributed to mammary epithelial growth during ductal morphogenesis, and the Rosa26-LacZ reporter gene was activated by WAP-Cre expression during pregnancy. Some NSC-derived LacZ⁺ cells expressed mammary-specific functions, including milk protein synthesis, whereas others adopted myoepithelial cell fates. Thus, NSCs and their progeny enter mammary epithelium–specific niches and adopt the function of similarly endowed mammary cells. This result supports the conclusion that tissue-specific signals emanating from the stroma and from the differentiated somatic cells of the mouse mammary gland can redirect the NSCs to produce cellular progeny committed to MEC fates.