Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Bairro Trindade, Cx Postal 5069, CEP: 88040-970, Florianópolis, Santa Catarina, Brazil.
Biochimie. 2012 Jan;94(1):146-54. doi: 10.1016/j.biochi.2011.10.001. Epub 2011 Oct 13.
It was characterized that the rapid response to 1α,25(OH)(2)-vitamin D(3) (1,25D(3)) on (45)Ca(2+) influx in rat Sertoli cells was mediated by voltage-dependent Ca(2+) channels (VDCCs), PKC, ERK1/2 and p38 MAPK pathways. In primary culture of 10 day-old rat Sertoli cells as well as in the whole testis, the time-course of (45)Ca(2+) influx did not change significantly in basal conditions. However, 1,25D(3) showed stimulatory effect on (45)Ca(2+) influx from 10(-15) to 10(-8) M after 60 s of incubation. The maximum effect was around 140% at 10(-12) M on purified Sertoli cells showing a steady state on (45)Ca(2+) influx between 10(-11) and 10(-9) M. Under this experimental condition, 1,25D(3) stimulated (45)Ca(2+) influx from 73% to 106% and no effect was observed at 10(-16), 10(-8) and 10(-7) M in whole testis. VDCC activities are mandatory for a full and complete stimulatory effect of 1,25D(3) in these approaches. K(+) and Cl(-) channels also are strongly involved in this rapid response coordinated by 1,25D(3). The participation of some selected kinases, points to PKC and ERK1/2 upstream activity to p38 MAPK activation suggesting an intracellular cross-talk between rapid (45)Ca(2+) influx and nuclear events. In addition, the comparative effect of microtubule disassembles and ClC-3 channel blocker on (45)Ca(2+) influx provides evidence of secretory activity of Sertoli cells triggered by 1,25D(3). Our results suggest that 1,25D(3) activates p38 MAPK and reorganizes microtubules, involving Ca(2+), PKC and ERK1/2 as upstream regulators and that extracellular Ca(2+) have a central role to rapidly start hormone-induced gene transcription and/or the secretory activity of Sertoli cell.
其特征在于，1α，25（OH）（2）-维生素 D（3）（1，25D（3））对大鼠支持细胞中（45）Ca（2+）内流的快速反应是由电压依赖性 Ca（2+）通道（VDCCs）、PKC、ERK1/2 和 p38 MAPK 途径介导的。在 10 天龄大鼠支持细胞的原代培养物以及整个睾丸中，基础条件下（45）Ca（2+）内流的时程没有明显变化。然而，1，25D（3）在孵育 60 秒后，在 10（-15）至 10（-8）M 时对（45）Ca（2+）内流表现出刺激作用。在纯化的支持细胞中，最大效应约为 10（-12）M 时为 140%，在 10（-11）至 10（-9）M 之间达到（45）Ca（2+）内流的稳态。在这种实验条件下，1，25D（3）刺激（45）Ca（2+）内流从 73%增加到 106%，在整个睾丸中，在 10（-16）、10（-8）和 10（-7）M 时没有观察到效应。VDCC 活性是 1，25D（3）在这些方法中充分和完全刺激的必要条件。K（+）和 Cl（-）通道也强烈参与了 1，25D（3）的这种快速反应的协调。一些选定的激酶的参与表明 PKC 和 ERK1/2 上游活性向 p38 MAPK 激活，提示快速（45）Ca（2+）内流和核事件之间存在细胞内串扰。此外，微管解聚和 ClC-3 通道阻滞剂对（45）Ca（2+）内流的比较效应提供了证据，证明 1，25D（3）触发了支持细胞的分泌活性。我们的结果表明，1，25D（3）激活 p38 MAPK 并重组微管，涉及 Ca（2+）、PKC 和 ERK1/2 作为上游调节剂，细胞外 Ca（2+）在快速启动激素诱导的基因转录和/或支持细胞的分泌活性方面起着核心作用。
