Relative contribution of chloride channels and transporters to regulatory volume decrease in human glioma cells

Author:

Ernest Nola Jean,Weaver Amy K.,Van Duyn Lauren B.,Sontheimer Harald W.

Abstract

Primary brain tumors (gliomas) often present with peritumoral edema. Their ability to thrive in this osmotically altered environment prompted us to examine volume regulation in human glioma cells, specifically the relative contribution of Clchannels and transporters to this process. After a hyposmotic challenge, cultured astrocytes, D54-MG glioma cells, and glioma cells from human patient biopsies exhibited a regulatory volume decrease (RVD). Although astrocytes were not able to completely reestablish their original prechallenge volumes, glioma cells exhibited complete volume recovery, sometimes recovering to a volume smaller than their original volumes (VPost-RVD< Vbaseline). In glioma cells, RVD was largely inhibited by treatment with a combination of Clchannel inhibitors, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and Cd2+(VPost-RVD> 1.4*Vbaseline). Volume regulation was also attenuated to a lesser degree by the addition of R-(+)-[(2- n-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-1 H-inden-5-yl)oxy]acetic acid (DIOA), a known K+-Clcotransporter (KCC) inhibitor. To dissect the relative contribution of channels vs. transporters in RVD, we took advantage of the comparatively high temperature dependence of transport processes vs. channel-mediated diffusion. Cooling D54-MG glioma cells to 15°C resulted in a loss of DIOA-sensitive volume regulation. Moreover, at 15°C, the channel blockers NPPB + Cd2+completely inhibited RVD and cells behaved like perfect osmometers. The calculated osmolyte flux during RVD under these experimental conditions suggests that the relative contribution of Clchannels vs. transporters to this process is ∼60–70% and ∼30–40%, respectively. Finally, we identified several candidate proteins that may be involved in RVD, including the Clchannels ClC-2, ClC-3, ClC-5, ClC-6, and ClC-7 and the transporters KCC1 and KCC3a.

Publisher

American Physiological Society

Subject

Cell Biology,Physiology

Cited by 103 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3