Primordial germ cell deficiency in the connexin 43 knockout mouse arises from apoptosis associated with abnormal p53 activation
Primordial germ cell deficiency in the connexin 43 knockout mouse arises from apoptosis associated with abnormal p53 activation
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DOI：
10.1242/dev.02506
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发表时间：
2006-09-01
期刊：
影响因子：
4.6
通讯作者：
Lo, Cecilia W.
中科院分区：
文献类型：
--
作者：
Francis, Richard J. B.;Lo, Cecilia W.
连接蛋白 43 敲除 (Cx43 α 1KO) 小鼠表现出生殖细胞缺陷，但生殖细胞缺陷的根本原因尚不清楚。使用 Oct4-GFP 报告基因转基因，我们追踪了 Cx43 α 1KO 小鼠胚胎中原始生殖细胞 (PGC) 的分布和迁移。染料注射分析表明 PGC 具有间隙连接通讯能力，在 Cx43 α 1 缺陷的 PGC 中染料偶联显着减少。延时视频显微镜和运动分析表明，Cx43 α 1KO PGC 中细胞运动的方向性和速度降低。在 E8.5 和 E11.5 胚胎中都观察到了这一点。相比之下，野生型和杂合/纯合 Cx43 α 1KO 胚胎之间的 PGC 丰度没有差异，直到 E11.5，此时在纯合 Cx43 α 1KO 胚胎中检测到 PGC 丰度显着降低。这伴随着 PGC 凋亡的增加和激活的 p53 表达的增加。注射p53拮抗剂α-pifithrin可抑制PGC凋亡并防止PGC丢失。使用细胞粘附测定的分析表明 Cx43 α 1KO PGC 中 β 1-整合素功能降低。连同 p53 的异常激活，这些发现表明失巢凋亡可能介导细胞凋亡。总体而言，这些研究结果表明，Cx43 α 1 对于 PGC 存活至关重要，异常 p53 激活在 Cx43 α 1 KO 小鼠胚胎中 PGC 凋亡损失中发挥着至关重要的作用。
Connexin 43 knockout (Cx43 alpha 1KO) mice exhibit germ cell deficiency, but the underlying cause for the germ cell defect was unknown. Using an Oct4-GFP reporter transgene, we tracked the distribution and migration of primordial germ cells (PGCs) in the Cx43 alpha 1KO mouse embryo. Analysis with dye injections showed PGCs are gap-junction-communication competent, with dye coupling being markedly reduced in Cx43 alpha 1-deficient PGCs. Time-lapse videomicroscopy and motion analysis showed that the directionality and speed of cell motility were reduced in the Cx43 alpha 1KO PGCs. This was observed both in E8.5 and E11.5 embryos. By contrast, PGC abundance did not differ between wild-type and heterozygous/homozygous Cx43 alpha 1KO embryos until E11.5, when a marked reduction in PGC abundance was detected in the homozygous Cx43 alpha 1KO embryos. This was accompanied by increased PGC apoptosis and increased expression of activated p53. Injection of alpha-pifithrin, a p53 antagonist, inhibited PGC apoptosis and prevented the loss of PGC. Analysis using a cell adhesion assay indicated a reduction in beta 1-integrin function in the Cx43 alpha 1KO PGCs. Together with the abnormal activation of p53, these findings suggest the possibility of anoikis-mediated apoptosis. Overall, these findings show Cx43 alpha 1 is essential for PGC survival, with abnormal p53 activation playing a crucial role in the apoptotic loss of PGCs in the Cx43 alpha 1KO mouse embryos.