Meissner Anja, Noack Thomas
Institute of physiology, University of Rostock, Gertrudenstrasse 9, Rostock, 18055, Germany.
Pflugers Arch. 2008 Oct;457(1):47-59. doi: 10.1007/s00424-008-0514-5. Epub 2008 May 1.
Calcium, as an integral part of a large number of cellular regulatory pathways, is selective in the control of specific cell functions like the start of G1 phase in cell cycle. Cell proliferation has been suggested to depend on increasing intracellular calcium levels. A major regulatory pathway for intracellular calcium is the calcium influx into the cell via voltage-gated calcium channels. T-type and L-type calcium channels are substantially present in human lens epithelial cell (hLEC), and total calcium currents are inhibited by mibefradil. Here, the hypothesis was tested if calcium influx via Ca(v) channels regulates proliferation in epithelial cells. Cell proliferation was determined by cell culture assays using the L- and T-type Ca(v) channel blockers mibefradil and verapamil as modulators for calcium influx. Calcium influx was investigated using the Manganese quench technique. Western blot experiments were accomplished under standard conditions using antibodies against MAPK 3. Mibefradil as well as verapamil impaired cell proliferation, but in different concentration ranges. Furthermore, the activation of MAPK 3 was reduced by both antagonists. Calcium influx was also reduced in the presence of both blockers. We conclude that the transmembrane influx of Ca(2+) through Ca(v) channels contributes to the regulation of hLEC proliferation, identifying Ca(v) channel blockers as potential therapeutic substances in ocular diseases.
钙作为大量细胞调节途径的一个组成部分，在控制特定细胞功能（如细胞周期中G1期的开始）方面具有选择性。细胞增殖被认为依赖于细胞内钙水平的升高。细胞内钙的主要调节途径是通过电压门控钙通道使钙流入细胞。T型和L型钙通道大量存在于人类晶状体上皮细胞（hLEC）中，米贝拉地尔可抑制总钙电流。在此，我们检验了一个假设，即通过Ca(v)通道的钙流入是否调节上皮细胞的增殖。使用L型和T型Ca(v)通道阻滞剂米贝拉地尔和维拉帕米作为钙流入的调节剂，通过细胞培养试验来测定细胞增殖。使用锰淬灭技术研究钙流入情况。在标准条件下，使用抗MAPK 3抗体完成蛋白质印迹实验。米贝拉地尔和维拉帕米均损害细胞增殖，但在不同的浓度范围内。此外，两种拮抗剂均降低了MAPK 3的激活。在两种阻滞剂存在的情况下，钙流入也减少。我们得出结论，Ca(2+)通过Ca(v)通道的跨膜流入有助于调节hLEC增殖，这表明Ca(v)通道阻滞剂是眼部疾病潜在的治疗物质。
