Rossi M A, Di Mauro C, Esterbauer H, Fidale F, Dianzani M U
Department of Experimental Medicine, University of Turin, Italy.
Cell Biochem Funct. 1994 Dec;12(4):275-80. doi: 10.1002/cbf.290120408.
A comparison has been made between the effects of 4-hydroxy-2,3-trans-nonenal (HNE) and 4-hydroxy-2,3-trans-octenal (HOE), two lipid peroxidation products, on the basal and GTPgammaS-stimulated activities of phosphoinositide-specific phospholipase C (PL-C) of rat polymorphonuclear leukocytes. PL-C activity was determined in vitro by measuring the hydrolysis of [3H] phosphatidylinositol-4,5-bis- phosphate (PtdIns-P2) added as exogenous substrate to neutrophil plasma membranes. PL-C was activated by concentrations of HNE ranging from 10(-8) to 10(-6) M both in the presence and in the absence of 2 x 10(-5) M GTPgammaS; HOE stimulated the enzymatic activity between 10(-11) and 10(-8) M; maximal stimulation was given by 10(-11) M HOE plus GTPgammaS. The aldehyde concentrations able to accelerate PtdIns-P2 breakdown displayed a good correspondence with those which have been reported to stimulate the oriented migration of rat neutrophils. Pretreatment of neutrophils with pertussis toxin prevented the stimulation of PL-C by 10(-11) M HOE and by HOE plus GTPgammaS. Our results suggest that the chemotactic action of HNE and HOE might depend on the activation of PL-C; furthermore a regulatory G protein appears to be involved in the acceleration of PtdIns-P2 turnover by HOE.
对两种脂质过氧化产物4-羟基-2,3-反式壬烯醛（HNE）和4-羟基-2,3-反式辛烯醛（HOE）对大鼠多形核白细胞磷酸肌醇特异性磷脂酶C（PL-C）的基础活性和GTPγS刺激活性的影响进行了比较。通过测量作为外源性底物添加到中性粒细胞膜中的[3H]磷脂酰肌醇-4,5-二磷酸（PtdIns-P2）的水解来体外测定PL-C活性。在存在和不存在2×10^(-5) M GTPγS的情况下，10^(-8)至10^(-6) M的HNE浓度均可激活PL-C；HOE在10^(-11)至10^(-8) M之间刺激酶活性；10^(-11) M HOE加GTPγS可产生最大刺激。能够加速PtdIns-P2分解的醛浓度与据报道能刺激大鼠中性粒细胞定向迁移的醛浓度具有良好的对应关系。用百日咳毒素预处理中性粒细胞可阻止10^(-11) M HOE以及HOE加GTPγS对PL-C的刺激。我们的结果表明，HNE和HOE的趋化作用可能取决于PL-C的激活；此外，一种调节性G蛋白似乎参与了HOE加速PtdIns-P2周转的过程。
