Serine/threonine phosphorylation in cellular signaling for alveolar macrophage phagocytic response to endotoxin.
Serine/threonine phosphorylation in cellular signaling for alveolar macrophage phagocytic response to endotoxin.
复制标题
肺泡巨噬细胞对内毒素吞噬反应的细胞信号传导中的丝氨酸/苏氨酸磷酸化。
DOI：
10.1097/00024382-200013010-00007
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Spitzer,JA
中科院分区：
文献类型：
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作者：
Zhang,P;Nelson,S;Summer,WR;Spitzer,JA
蛋白丝氨酸/苏氨酸（ser/thr）磷酸化是巨噬细胞活化中的早期信号事件。本研究观察了内毒素诱导大鼠肺泡巨噬细胞（AM）应激活化蛋白激酶/c-Jun氨基末端激酶（SAPK/JNK）活性的变化及磷酸酶抑制剂对AM功能的影响。在气管内脂多糖（LPS，100 [mu] g/大鼠）攻击后90分钟处死动物。AM与或不与磷酸酶抑制剂在37 [degree] C下孵育30 min。测定AM的吞噬作用、CD 18表达、SAPK/JNK和磷酸酶活性。LPS刺激激活SAPK/JNK活性，增强AM的吞噬作用，而不改变这些细胞中的磷酸酶活性。抑制磷酸酶1和2A的活性与冈田酸和calyculin A对AM吞噬功能产生双相效应。冈田酸在浓度为1 [mu] M增加平均通道荧光强度（MCF）和细胞的百分比参与吞噬作用（吞噬百分比）在AM从盐水处理的大鼠。这种抑制剂在浓度为0.5和1 [mu] M增强MCF和百分比吞噬AM从LPS攻击的大鼠。Calyculin A在10 nM的浓度下增加了来自LPS攻击的大鼠的AM的MCF吞噬作用。在较高浓度（20和30 nM）下，calyculin A显示出对盐水和LPS组中AM的MCF和吞噬百分比的抑制。AM CD 18表达在LPS攻击后没有改变。磷酸酶抑制剂在增强AM吞噬作用的剂量下显示出对AM CD 18表达没有影响（冈田酸）或抑制（calyculin A）。这些结果表明，丝氨酸/苏氨酸磷酸化和去磷酸化参与介导AM对LPS的吞噬反应。
mdash;: Protein serine/threonine (ser/thr) phosphorylation is an early signaling event in macrophage activation. We investigated the changes in stress-activated protein kinase/c-Jun NH2-terminal kinase (SAPK/JNK) activity and effects of phosphatase inhibition on alveolar macrophage (AM) function in rats challenged with intratracheal endotoxin. Animals were sacrificed 90 min post intratracheal lipopolysaccharide (LPS, 100 [mu] g/rat) challenge. AMs were incubated with or without phosphatase inhibitors at 37 [degrees] C for 30 min. Phagocytosis, CD18 expression, SAPK/JNK and phosphatase activities of AMs were determined. LPS challenge activated SAPK/JNK activity and enhanced phagocytosis of AMs without altering phosphatase activity in these cells. Inhibition of phosphatase 1 and 2A activity with okadaic acid and calyculin A exerted a bi-phasic effect on AM phagocytic function. Okadaic acid at a concentration of 1 [mu] M increased the mean channel fluorescence intensity (MCF) and the percentage of cells engaged in phagocytosis (percent phagocytosis) in AMs from saline-treated rats. This inhibitor at concentrations of 0.5 and 1 [mu] M enhanced both the MCF and percent phagocytosis of AMs from LPS-challenged rats. Calyculin A at a concentration of 10 nM increased the MCF phagocytosis of AMs from LPS-challenged rats. At higher concentrations (20 and 30 nM), calyculin A showed a suppression on both the MCF and percent phagocytosis of AMs in both saline and LPS groups. AM CD18 expression was not altered following LPS challenge. Phosphatase inhibitors at doses that enhanced AM phagocytosis showed either no effect (okadaic acid) or inhibition (calyculin A) of AM CD18 expression. These results suggest that ser/thr phosphorylation and dephosphorylation participate in mediating the phagocytic response of AMs to LPS.