Larrazabal C S, Carretta M D, Hidalgo M A, Burgos R A
Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile.
Laboratory of Molecular Pharmacology, Institute of Pharmacology and Morphophysiology, Faculty of Veterinary Science, Universidad Austral de Chile, PO Box 567, Valdivia, Chile.
Vet Immunol Immunopathol. 2017 Sep;191:68-73. doi: 10.1016/j.vetimm.2017.08.007. Epub 2017 Aug 26.
Cytoplasmic pH homeostasis is required for an appropriate response in polymorphonuclear neutrophils (PMNs). In these cells, chemotaxis and reactive oxygen species (ROS) production are reduced by the use of Na/H exchanger (NHE-1) inhibitors, but these results are mainly obtained using amiloride, a non-selective NHE-1 inhibitor. In bovine PMNs, the role of NHE-1 in functional responses has not been confirmed yet. The aim of this study was to determine the role of NHE-1 using amiloride and zoniporide in pH regulation, ROS production, matrix metalloproteinase 9 (MMP-9) release and calcium flux in bovine PMNs induced by the platelet activation factor (PAF), additionally we evaluated the presence of NHE-1 and NHE-2 mRNA Our data show the presence only of NHE-1 but not NHE-2 in bovine PMNs. Amiloride or zoniporide inhibited the intracellular alkalization induced by PAF without affecting calcium flux. Amiloride diminished ROS production and MMP-9 release, while zoniporide enhanced ROS production without change the MMP-9 release induced by PAF. Our work led us to conclude that changes in intracellular pH induced by PAF are regulated by NHE-1 in bovine neutrophils, but the effects of amiloride on ROS production and MMP-9 release induced by PAF are not NHE-1 dependent.
细胞质pH稳态是多形核中性粒细胞（PMN）做出适当反应所必需的。在这些细胞中，使用钠/氢交换体（NHE-1）抑制剂会降低趋化性和活性氧（ROS）的产生，但这些结果主要是使用非选择性NHE-1抑制剂阿米洛利获得的。在牛PMN中，NHE-1在功能反应中的作用尚未得到证实。本研究的目的是使用阿米洛利和唑尼泊利来确定NHE-1在血小板活化因子（PAF）诱导的牛PMN的pH调节、ROS产生、基质金属蛋白酶9（MMP-9）释放和钙通量中的作用，此外，我们评估了NHE-1和NHE-2 mRNA的存在情况。我们的数据显示牛PMN中仅存在NHE-1而不存在NHE-2。阿米洛利或唑尼泊利抑制了PAF诱导的细胞内碱化，而不影响钙通量。阿米洛利减少了ROS的产生和MMP-9的释放，而唑尼泊利增强了ROS的产生，但不改变PAF诱导的MMP-9释放。我们的研究得出结论，PAF诱导的牛中性粒细胞内pH变化由NHE-1调节，但阿米洛利对PAF诱导的ROS产生和MMP-9释放的影响并非NHE-1依赖性。
