EFFECT OF GROWTHFACTOR (S) ON CEREBRAL HISTOGENESIS : ANALYSIS ON TISSUE CULTRED EXPLANT

生长因子 (S) 对脑组织发生的影响：组织培养外植体的分析

基本信息

批准号：
09670834
负责人：
TAKAHASHI Takao
金额：
$ 1.98万
依托单位：
KEIO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670834/
关键词：
Cerebral Histogenesis Mouse Cell Cycle Tissue Culture Gap Junction Basic Fibroblast Growth Factor Octanol 分化大脳皮質発生細胞周期組織培養

项目摘要

Analysis of cell cycle regulation in neocortical neuronogenesis has been undertaken in vitro in the embryonic day 13 mouse. Explants of the dorsomedial region of the cerebral wall, implanted in collagen gel, were incubated for 1 hr in minimal medium and then in minimal medium containing BUdR.After 30 mm with BUdR (1.5 hr in vitro), the labeling index (LI, labeled/total cells) was 0.41 as compared to the previously determined LI of 0.38 in vivo. The in vitro LI remained at 0.4 over the next 7 hr of continued exposure to BUdR and then ascended linearly to asymptote at 0.73. These observations establish (1) that there is a flux of cells from G1 to S for the first 1.5 hr in vitro, (2) that this G1 to S flux is then interrupted for the following 7 hr but (3) that G1 to S flux is subsequently reestablished. In this same system, mitotic figures were first labeled only after a 5 hr exposure to BUdR but then over 2 more hours all mitoses became labeled. In vivo, by contrast, all mitoses become … More labeled during 2 hr of BUdR exposure. By implication there is a transient arrest in the progression from S to M phase which is evidently overcome within 5 hr of explantation. The duration of the reestablished cell cycle and those of G1, Sand combined G2-M phases were estimated to be 19.2, 6.3 -8.3, 8.8, and 2.0 -4.0 hr, respectively. The leaving (Q) fraction of the cycle (0,64) was twice the in vivo value. Two thirds of the Q fraction cells remained in the ventricular epithelium, resulting in a substantially low growth fraction of 0.73 as compared with 1.0 in vivo.Also examined in a cerebral wall explant in vitro was the consequences of basic fibroblast growth factor (b-FGF) and the gap junction uncoupling agent, 1-octanol. LI was determined in the sector of the medial and lateral cortical zones, corresponding to areas 1 and 40, respectively. In area 40, the overall LI in b-FGF-exposed explants was higher and that in 1-octanol-exposed explants was lower than the LI in control explants. Those observations suggest that b-FGF reduces Q fraction while 1-octanol increases the fraction. Less

在胚胎13小鼠中，已经在体外进行了新皮质神经发生的细胞周期调节分析。将植入胶原凝胶的大脑壁背侧区域的外植体在最小培养基中孵育1小时，然后在含Budr的最小培养基中孵育1小时。与BUDR 30 mm（1.5小时的体外），该标签索引（Li，Total/Total Cells）与先前确定的0.38在0.38中相比。在接下来的7小时持续暴露于BUDR的情况下，体外LI保持在0.4，然后线性地升到0.73的渐近线。这些观察结果表明（1）在最初的1.5小时体外存在从G1到S的通量，（2）随后将G1到S通量中断为接下来的7小时，但（3）随后重新建立了G1到S flux。在同一系统中，仅在5小时暴露于BUDR后才将有丝分裂数字贴上标签，但在超过2个小时以上，所有有丝分裂都被标记了。相比之下，在体内，所有有丝分裂都变得……在2小时的BUDR暴露期间更加标记。暗示着从s到m相的进展中存在短暂停滞，显然在膨胀的5小时内就可以克服。重新建立的细胞周期和G1的持续时间估计分别为19.2、6.3 -8.3、8.8和2.0 -4.0小时。周期（0,64）的离开（q）分数是体内值的两倍。 Q分数的三分之二保留在心室上皮中，与体内1.0相比，在体外检查的1.0同时，在体外检查的是0.73，这是基本成纤维细胞生长因子（B-FGF）的后果，而GAP交界连接剂脱离了碱性纤维细胞生长因子（B-FGF）的后果。 LI分别在培养基和侧面皮质区域确定，分别对应于1和40区域。在40区域中，B-FGF暴露的外植体中的整体LI较高，并且在1-辛醇暴露的外植体中，LI在对照外植体中低于LI。这些观察结果表明，B-FGF降低了Q分数，而1-二二醇增加了分数。较少的