Effect of temperature on in vitro proliferative activity of human umbilical vein endothelial cells

Human umbilical vein endothelial cells, skin fibroblasts, and retinal pigment epithelial cells are cultivated in medium supplemented with 15 to 20% serum in our laboratory. The effects of various incubation temperatures on the proliferation of these cells was examined. Our study shows that the mitogenic response of the endothelial cells to a change of temperature differed markedly from that of the fibroblasts and epithelial cells. Cultivation of human umbilical vein endothelial at 37°C required seeding densities as high as 1–2×10⁴ cells/cm², and yet resulted in a low growth rate and premature senescence. However, under the same culture conditions, but at 33°C, the proliferative capacity of these endothelial cells was potentiated. The results were striking; at 33°C the cells grew actively and the life span was extended. The number of cumulative population doublings increased fourfold compared with that for the same cells cultivated at 37°C. The inoculum size could be reduced, since at 33°C the endothelial cells were able to replicate at seeding densities as low as 20 cells/cm². The cells serially subcultured at 33°C retained morphological features and specific immunological markers of endothelial cells.     

Regulations of thyroid hormone on cardiac protein kinase C signal pathway in vitro

The experiments were conducted to assess the influences of thyroid hormone on cardiac protein kinase C(PKC) signal pathway with cultured cardiac myocytes and fibroblasts as the models. Cells were pretreated with 1% newborn calf serum (NCS) or angiotensin II (Ang II), and then following by a triiodothyronine (T3) treatment. The PKC activity, PKC_α and PKC_ε expressions were analyzed and compared. In 1% NCS pretreatment, T3 could inhibit PKC activity and PKC_ε expression in cardiac myocytes. The AngII pretreatment led to an increase of PKC activity and PKC_ε expression in cardiac myocytes, and an increase of PKC activity in cardiac fibroblasts. Following by T3 treatment, the increased PKC activity and PKC_ε expression in cardiac myocytes were markedly decreased. In conclusion, whether in 1% NCS or in Ang II pretreatment, T3 could inhibit PKC activity and PKC_ε expression in cardiac myocytes. Foundation item: Supported by the Natural Science Foundation of Hubei Province (98091) Biography: WANG Bao-hua (1974-), female, Ph. D, research direction: cardiovascular pathophysiology.     

不同血清对山羊成纤维细胞传代的影响

考察不同血清对山羊成纤维细胞传代培养的影响．第6～8代细胞分别在添加10％Hyclone和10％四季青胎牛血清的DMEM中传代培养，实验发现，前者平均增殖倍数和群体倍增次数均高于后者．随着传代次数的增多，细胞在四季青血清培养液中的生长行为发生明显变化，细胞不能倍增且生长曲线呈不规则波动状．结果表明，细胞传代过程中使用不同血清会改变细胞生物学特性，降低细胞活力．用这种方式传代的细胞不宜用作核移植供体细胞及其他实验研究．     

全反式维甲酸对人真皮成纤维细胞RXR的表达影响

Ｎｏｒｔｈｅｒｎ杂交检测人真皮成纤维细胞维甲类Ｘ受体（ＲＸＲ）的表达。结果显示,细胞中只有ＲＸＲα和β的信息ＲＮＡ表达,无γ受体信息ＲＮＡ表达;用全反式维甲酸（ＡＴ－ＲＡ）刺激细胞于不同时段,对ＲＸＲ家族无诱导作用。表明人真皮成纤维细胞ＲＸＲ基因家族的表达调节完全不同于ＲＡＲ基因家族