Cell volume regulation in T lymphocytes

1.细胞体积调节对于细胞周期进程、凋亡和迁移等多种基本细胞功能至关重要。研究表明，K^+通道、Cl-通道、水通道、Na^+/H^+交换体和TRP通道参与了细胞体积的调节。进行RT-PCR分析以检测Jurkat细胞和人T细胞中ClC通道和水通道蛋白的表达。ClC-3A、ClC-3B和ClC-5在Jurkat细胞和人T细胞中表达，ClC-4在人T细胞中表达。AQP 3在Jurkat细胞和人T细胞中表达，AQP 1和AQP 8在人T细胞中表达。在Jurkat细胞中还检测了TRP通道和Na^+/H^+交换体的表达。TRPC 1、TRPC 3、TRPC 4和NHE-1在Jurkat细胞中表达。2.建立了分别过表达ClC-3A（Jurkat-3A）、ClC-3B（Jurkat-3B）和AQP 1（Jurkat-AQP 1）的Jurkat细胞系。当细胞暴露于40%低渗溶液时，与对照细胞相比，所有这些细胞系中的调节体积减小速率加快。3.在Jurkat-3B中，而不是在Jurkat-3A中，增殖速率加快。4.过表达ClC-3通道不影响Jurkat细胞的激活诱导的细胞死亡。5.在改良的Boyden小室试验中，Jurkat-3B中的细胞迁移增加。6.这些结果表明，ClC-3A，ClC-3B，AQP 1和AQP 3参与T细胞的细胞体积调节，并暗示ClC-3B在Jurkat细胞增殖和迁移中的重要和独特的作用。对这些通道和转运蛋白相互作用的深入研究将为深入理解细胞体积调节的分子基础提供重要线索。

1. Cell volume regulation is essential for various fundamental cell functions including cell cycle progression, apoptosis and migration. It has been suggested that K^+ channels, Cl- channels, water channels, Na^+/H^+ exchangers, and TRP channels are involved in cell volume regulation. RT-PCR analysis was performed to examine the expression of ClC channels and aquaporins in Jurkat cells and human T cells. ClC-3A, ClC-3B and ClC-5 were expressed in Jurkat cells and human T cells, and ClC-4 was expressed in human T cells. AQP3 was expressed in Jurkat cells and human T cells, and AQP1 and AQP8 were expressed in human T cells. The expression of TRP channels and Na^+/H^+ exchangers was also examined in Jurkat cells. TRPC1, TRPC3, TRPC4 and NHE-1 were expressed in Jurkat cells. 2. Jurkat cell lines overexpressing ClC-3A (Jurkat-3A), ClC-3B (Jurkat-3B) and AQP1 (Jurkat-AQP1), respectively, were established. When the cells were exposed to 40% hypotonic solution, the rate of the regulatory volume decrease was accelerated in all these cell lines in comparison with control cells. 3. In Jurkat-3B but not in Jurkat-3A, the rate of proliferation was accelerated. 4. The activation-induced cell death of Jurkat cells was not affected by overexpressing ClC-3 channels. 5. Cell migration was increased in Jurkat-3B in modified Boyden chamber assay. 6. These results suggest that ClC-3A, ClC-3B, AQP1 and AQP3 are involved in cell volume regulation in T cells, and implicate important and unique roles of ClC-3B in Jurkat cell proliferation and migration. Further analysis on protein-protein interactions involving these channels and transporters will provide an important clue to better understand the molecular basis of cell volume regulation.