Tedeschi A, Lorini M, Gibelli S, Miadonna A
Respiratory Allergy and Immunopharmacology Unit, Third Division of Internal Medicine, IRCCS Ospedale Maggiore Policlinico, Milan, Italy.
Inflamm Res. 2000 Sep;49(9):480-5. doi: 10.1007/s000110050620.
This study was aimed to evaluate the effects of two protein kinase C (PKC) inhibitors (staurosporine and chelerythrine) and one phospholipase C (PLC) inhibitor (U73122) on basophil histamine release induced by anti-IgE, N-formyl-methionyl-leucyl-phenylalanine (FMLP), IL-3 and GM-CSF.
Leukocytes were suspended in solutions containing physiological or low Na+ concentrations, since IL-3 and GM-CSF were shown to induce histamine release only when the inhibitory effect of extracellular Na+ has been removed. After incubation with PKC and PLC inhibitors, the stimuli were added and histamine release was measured by an automated fluorometric method.
Staurosporine and chelerythrine exerted a significant inhibitory effect on histamine release induced by anti-IgE, IL-3 and GM-CSF at concentrations much higher than those required to inhibit PKC. FMLP-induced histamine release in a physiological Na+-containing medium was not significantly modified by staurosporine, although it was reduced by high concentrations of chelerythrine. A slight inhibition by high concentrations of staurosporine was found when basophils were suspended in a low Na+ medium. U73122 exerted a significant and dose-dependent inhibitory effect on basophil histamine release induced by anti-IgE, FMLP, IL-3 and GM-CSF.
These results suggest that a prodegranulatory role of PKC in basophil histamine release induced by anti-IgE, FMLP, IL-3 and GM-CSF is unlikely; conversely, it is conceivable that PLC has a role in signal transduction and histamine release induced by the above stimuli.
本研究旨在评估两种蛋白激酶C（PKC）抑制剂（星形孢菌素和白屈菜红碱）以及一种磷脂酶C（PLC）抑制剂（U73122）对由抗IgE、N-甲酰甲硫氨酰亮氨酰苯丙氨酸（FMLP）、白细胞介素-3（IL-3）和粒细胞-巨噬细胞集落刺激因子（GM-CSF）诱导的嗜碱性粒细胞组胺释放的影响。
将白细胞悬浮于含有生理浓度或低钠浓度的溶液中，因为已表明IL-3和GM-CSF仅在细胞外钠的抑制作用被消除时才诱导组胺释放。在用PKC和PLC抑制剂孵育后，加入刺激物，并通过自动荧光法测量组胺释放。
星形孢菌素和白屈菜红碱在远高于抑制PKC所需浓度时，对由抗IgE、IL-3和GM-CSF诱导的组胺释放产生显著抑制作用。在含生理钠浓度的培养基中，星形孢菌素对FMLP诱导的组胺释放无显著影响，尽管高浓度的白屈菜红碱可使其降低。当嗜碱性粒细胞悬浮于低钠培养基中时，高浓度的星形孢菌素有轻微抑制作用。U73122对由抗IgE、FMLP、IL-3和GM-CSF诱导的嗜碱性粒细胞组胺释放产生显著且剂量依赖性的抑制作用。
这些结果表明，PKC在由抗IgE、FMLP、IL-3和GM-CSF诱导的嗜碱性粒细胞组胺释放中不太可能具有促脱颗粒作用；相反，可以想象PLC在上述刺激诱导的信号转导和组胺释放中发挥作用。
