Human cytomegalovirus infection enhances osmotic stimulation of Na+/H+ exchange in human fibroblasts.
Human cytomegalovirus infection enhances osmotic stimulation of Na+/H+ exchange in human fibroblasts.
复制标题
人巨细胞病毒感染增强人成纤维细胞中 Na /H 交换的渗透刺激。
DOI：
10.1152/ajpcell.1997.273.5.c1739
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Russell,JM
中科院分区：
文献类型：
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作者：
Crowe,WE;Altamirano,AA;Russell,JM
人巨细胞病毒 (HCMV) 感染会导致人成纤维细胞 (MRC-5) 增大（细胞肿大）。作为确定部分由 Na+/H+ 交换介导的溶质摄取是否导致细胞肥大发生的第一步，我们通过比较细胞肥大细胞与模拟感染的细胞，研究了 HCMV 感染对细胞内 pH (pHi) 调节（标称 CO2/浓度 = 0）的影响。 HCMV 感染 MRC-5 细胞 72 小时后，我们观察到相对于模拟感染细胞的以下变化：静息 pH 值偏碱性 0.1-0.2 个 pH 单位；细胞质的内在缓冲能力降低了~40-50%；酸负载 H+ 等效通量减少； Na+/H+交换器 (NHE) 特性发生了改变，包括活性 pHi 依赖性的碱性转变、细胞外 Na+ 的表观亲和力降低、表观最大速度增加以及高渗挑战引起的刺激大幅增加。这些结果表明，HCMV 感染对 NHE 的功能特性、酸负荷机制和内在细胞缓冲能力产生深远影响。这些效应与 NHE 在细胞肿大发展中的作用一致。
Infection with human cytomegalovirus (HCMV) causes an enlargement (cytomegaly) of human fibroblasts (MRC-5). As a first step toward determining whether solute uptake, mediated in part by Na+/H+exchange, is responsible for the development of cytomegaly, we studied the effects of HCMV infection on intracellular pH (pHi) regulation (nominal CO2/concn = 0) by comparing cytomegalic cells with mock-infected cells. Seventy-two hours after HCMV infection of MRC-5 cells we observed the following changes relative to mock-infected cells: resting pHiis 0.1–0.2 pH unit more alkaline; the intrinsic buffering power of the cytoplasm was reduced by ∼40–50%; acid-loading H+-equivalent fluxes were reduced; and there were alterations of Na+/H+exchanger (NHE) properties, including an alkaline shift of the pHidependence of activity, a reduction of the apparent affinity for extracellular Na+, and an increase of the apparent maximum velocity and a large increase in stimulation by a hyperosmotic challenge. These results indicate that HCMV infection exerts a profound effect on functional properties of the NHE, on acid-loading mechanisms, and on intrinsic cellular buffering power. These effects are consistent with a role for the NHE in the development of cytomegaly.