Dimethylsphingosine increases cytosolic calcium and intracellular pH in human T lymphocytes
Dimethylsphingosine increases cytosolic calcium and intracellular pH in human T lymphocytes
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DOI：
10.1016/s0006-2952(02)01519-8
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发表时间：
2003-02-01
影响因子：
5.8
通讯作者：
Botana, LM
中科院分区：
文献类型：
--
作者：
Alfonso, A;De la Rosa, LA;Botana, LM
N，N-二甲基- d -红-斯皮纳辛（DMS）是斯皮纳辛的N-甲基衍生物；两者都是鞘氨醇依赖性蛋白激酶的激活剂。本研究旨在研究DMS对人T淋巴细胞胞质钙和细胞内pH （pHi）的影响。分别采用Fura-2-AM和BCECF-AM荧光数字成像测定钙和pH的变化。DMS增加了人T淋巴细胞的pHi和Ca2+细胞浓度。这些效应是剂量依赖性的。该药物诱导pHi快速增加，并从不同的细胞内钙池中释放钙，而不是thapsigarin。DMS还诱导Ca2+内流，这与储存操作的钙通道不同，因为药物效应没有被30mum SKF 96365改变。在镍或镧的预孵育下，DMS诱导的钙内流被完全阻断，而pHi的增加不受影响。然而，镉的存在减少但不阻止Ca2+内流。100 ng/mL百日咳毒素对g蛋白的抑制和染料木素对酪氨酸激酶的抑制，通过抑制细胞内钙池的释放和细胞外介质的内流，显著降低了DMS诱导的胞质钙的增加。这些药物对池空化的抑制作用与其对DMS细胞质碱性的抑制作用有关。总之，DMS增加pHi，从而从细胞内池中释放钙，并通过不同于储存操作通道（SOC）的通道增加钙流入。胞质钙和pHi的增加均受g蛋白和酪氨酸激酶的调节。(C) 2002爱思唯尔科学有限公司版权所有。
N,N-Dimethyl-D-erythro-sphinaosine (DMS) is the N-methyl derivative of sphingosine; both are activators of sphingosine-dependent protein kinases. The aim of this work was to study the effect of DMS on cytosolic calcium and intracellular pH (pHi) in human T lymphocytes. The variations of calcium and pH were determined by fluorescence digital imaging using Fura-2-AM and BCECF-AM, respectively. DMS increased both pHi and Ca2+-cytoslic in human T lymphocytes. These effects were dose-dependent. This drug induced a fast increase in pHi and a release of calcium from different intracellular calcium pools than thapsigargin. DMS also induced a Ca2+- influx different from the store-operated calcium channels, since drug effect was not modified by 30 muM SKF 96365. The influx of calcium induced by DMS was completely blocked by preincubation in the presence of nickel, or lanthanum, while the increase in pHi was no affected. However, the presence of cadmium reduced but does not block Ca2+-influx. The inhibition of G-protein by 100 ng/mL pertussis toxin, and the inhibition of tyrosine kinases by genistein significantly reduced the cytosolic calcium increase induced by DMS by an inhibition of both, release of calcium from intracellular pools and influx from extracellular medium. The inhibition of pools emptiness by these drugs was related with the inhibition that they induce in the DMS cytosolic alcalinization. In summary, DMS increases pHi and as consequence releases calcium from intracellular pools, and it increases calcium-influx through a channel different from store-operated channel (SOC). Both cytosolic calcium and pHi increase are modulated by G-proteins and tyrosine kinases. (C) 2002 Elsevier Science Inc. All rights reserved.