Connexin50 is essential for normal postnatal lens cell proliferation
Connexin50 is essential for normal postnatal lens cell proliferation
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DOI：
10.1167/iovs.04-0194
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发表时间：
2004-09-01
影响因子：
4.4
通讯作者：
White, TW
中科院分区：
文献类型：
--
作者：
Sellitto, C;Li, LP;White, TW
目的。 Connexin50 (Cx50) 对于产后晶状体的正常生长至关重要。通过敲入删除 Cx50 或用 Cx46 替换，会产生包含更少细胞的更小晶状体。为了确定 Cx50 缺陷晶状体无法正常生长的原因，在生长失败期间测定了细胞增殖。方法。野生型、Cx50 敲除小鼠和 Cx50KI46 小鼠注射 5'-溴-2'-脱氧尿苷 (BrdU)，1 小时或 24 小时后解剖并固定晶状体。通过免疫细胞化学染色观察 BrdU 掺入情况，并在出生后第 0 天 (P) 和 P6 之间测定有丝分裂指数 (MI)。通过蛋白质印迹分析测定总 ERK 和磷酸-ERK 的水平。 结果。在 P2 至 P3 期间，野生型晶状体显示出 MI 显着增加，而敲除晶状体中并不明显，而敲除晶状体仅部分挽救了生长缺陷。有丝分裂细胞数量的减少并不反映细胞分裂速率的降低，并且与晶状体质量的减少在时间上相关。野生型和 Cx50 缺陷晶状体上皮细胞中磷酸化 ERK1/2 的水平相同。结论。这些结果表明，Cx50 介导的通讯对于实现有丝分裂峰值是必要的。此外，他们还提出了间隙连接偶联的一种新的有丝分裂作用，该作用是连接蛋白特异性的且独立于 MAPK 信号传导。
PURPOSE. Connexin50 (Cx50) is absolutely essential for normal postnatal lens growth. Deletion of Cx50 or replacement with Cx46 by knockin resulted in smaller lenses containing fewer cells. To determine why Cx50-deficient lenses fail to grow normally, cell proliferation was assayed during the period of growth failure.METHODS. Wild-type, Cx50-knockout, and Cx50KI46 mice were injected with 5'-bromo-2'-deoxyuridine ( BrdU) and lenses were dissected and fixed after 1 hour or 24 hours. BrdU incorporation was visualized by immunocytochemical staining, and the mitotic index (MI) was determined between postnatal day (P) 0 and P6. Levels of total ERK and phospo-ERK were determined by Western blot analysis.RESULTS. On P2 to P3, wild-type lenses displayed a significantly increased MI not evident in knockout lenses, and knockin lenses only partially rescued the growth deficit. Reductions in the number of mitotic cells did not reflect a decrease in the rate of cell division and temporally correlated with reduction in lens mass. Levels of phosphorylated ERK1/2 were identical in wild-type and Cx50-deficient lens epithelia.CONCLUSIONS. These results demonstrate that Cx50-mediated communication is necessary to achieve peak mitosis. In addition, they suggest a novel mitogenic role for gap junctional coupling that is connexin specific and independent of MAPK signaling.