体外培养获取高纯度O-2A祖细胞

目的获取较高纯度的O-2A祖细胞,并观察在不同的实验条件下O-2A祖细胞的分化作用。方法 根据星形胶质细胞、O-2A祖细胞的生长时间差异,细胞的粘附特性不同,采用振荡和差速贴壁法结合Ⅰ型星形胶质细胞条件培养液,培养、分离纯化O-2A祖细胞。结果培养的o-2A祖细胞胞体呈椭圆形,有典型的双极突起,少数呈三极突起;经免疫组织化学染色鉴定细胞的纯度达90％。在有血清的情况下,O-2A祖细胞定向分化为Ⅱ型星形胶质细胞;在无血清的情况下,其定向分化为少突胶质细胞。结论通过振荡法和Ⅰ型星形胶质细胞条件培养液结合差速贴壁法分离纯化培养O-2A祖细胞是一种可行的培养方法。     

凋亡抑制蛋白FLIP在肝癌组织中的表达和意义

目的检测凋亡抑制蛋白FLIP在人肝癌不同分化组织中的表达并揭示其在肝癌发生发展中的意义。方法采用免疫组织化学技术，分析86例肝癌标本（采用经典的Edmondson四级分级法，Ⅰ级18例，Ⅱ级25例，Ⅲ级21例，Ⅳ级22例），肝癌Hepg2细胞系1株细胞爬片的10样本中FLIP蛋白的表达并进行统计学分析比较。结果凋亡抑制蛋白FLIP在86例肝癌标本中有72例阳性表达（83．72％），Ⅰ级13／18（72．22％），Ⅱ级20／25（80．00％），Ⅲ级18／21（85．71％），Ⅳ级21／22（95．45％）（P〈0．05）；在肝癌Hepg2细胞系细胞爬片10个样本中全部阳性表达（100％），（P〈0．01）。结论凋亡抑制蛋白FLIP在肝癌组织中呈阳性表达；不同分化的肝癌组织其表达阳性率不同，分化越差其阳性表达率越高；这可能为揭示肝脏恶性肿瘤的发生、发展提供新的理论依据，并为肝癌的有效治疗提供新的思路。     

Adult pancreatic stem/progenitor cells spontaneously differentiate in vitro into multiple cell lineages and form teratoma-like structures

Cells isolated from pancreas have a remarkable potential for self-renewal and multilineage differentiation. We here present a comprehensive characterisation of stem/progenitor cells derived from exocrine parts of the adult rat pancreas. Using purified cells from either single colonies or even single-cell clones, we specifically demonstrate: (i) the cells contain the typical stem/progenitor cell markers alkaline phophatase, SSEA-1, Oct-4, CD9, Nestin, Pax6, CD44, -Fetoprotein and Brachyury, demonstrated by immunocytochemistry and RT-PCR; (ii) the cells have the potential to differentiate into lineages of all three germ layers in vitro; (iii) a clonal analysis revealed that even cell lines derived from a single cell have stem/progenitor cell properties such as self-renewal and spontaneous differentiation into various cell lineages; (iv) the cells have the propensity to form three-dimensional, teratoma-like structures in vitro, which contain cells of different lineages; and (v) external stimuli can activate the generation of certain cell types. For instance, cells treated with retinoic acid show an increased expression of -smooth muscle actin.

These results suggest that exocrine glands, such as pancreas may be a potential source of adult stem/progenitor cells, suitable for cell therapy of degenerative diseases.