Hypertonic preconditioning inhibits macrophage responsiveness to endotoxin
Hypertonic preconditioning inhibits macrophage responsiveness to endotoxin
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DOI：
10.4049/jimmunol.168.3.1389
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发表时间：
2002-02-01
影响因子：
4.4
通讯作者：
Maier, RV
中科院分区：
文献类型：
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作者：
Cuschieri, J;Gourlay, D;Maier, RV
高渗盐水已被证明可以调节细胞形状和先天免疫应答组分的应答。然而，高渗盐水对巨噬细胞的影响尚不清楚。我们假设，高渗预处理将损害随后的炎症介质信号通过减少应力纤维聚合和丝裂原活化蛋白激酶活性后LPS刺激。用100 ng/ml LPS刺激兔肺泡巨噬细胞。将选择的细胞用40-100 mM NaCl、甘露醇或尿素预处理4小时，并在LPS刺激前返回等渗培养基。收获细胞蛋白并进行蛋白质印迹分析，以确定p38和细胞外信号相关激酶（ERK）1/2的双重磷酸化活性形式。通过L929生物测定法测定TNF产生，并通过共聚焦显微镜评价应力纤维聚合。用NaCl或甘露醇预处理巨噬细胞导致ERK 1/2磷酸化的剂量依赖性降低，而对p38磷酸化没有影响。尿素预处理对丝裂原活化蛋白激酶无影响。用NaCl和甘露醇预处理观察到TNF产生的剂量依赖性衰减（p < 0.05），但用尿素未观察到。NaCl和甘露醇预处理导致LPS诱导的应力纤维聚合失败，而尿素没有。细胞外高渗条件（即，NaCl和甘露醇）对巨噬细胞具有免疫调节作用，通过最佳应力纤维聚合、ERK 1/2活性和TNF产生的失败来证明。细胞内高渗条件（即，尿素）无明显影响。因此，高渗盐水或甘露醇复苏可能有助于预防多器官功能障碍综合征，因为这种促炎反应性降低。
Hypertonic saline has been shown to modulate cell shape and the response of components of the innate immune response. However, the effect of hypertonic saline on the macrophage remains unknown. We hypothesized that hypertonic preconditioning would impair subsequent inflammatory mediator signaling through a reduction in stress fiber polymerization and mitogen-activated protein kinase activity after LPS stimulation. Rabbit alveolar macrophages were stimulated with 100 ng/ml of LPS. Selected cells were preconditioned with 40-100 mM of NaCl, mannitol, or urea for 4 h and returned to isotonic medium before LPS stimulation. Cellular protein was harvested and subjected to Western blot analysis for the dually phosphorylated active forms of p38 and extracellular signal-related kinase (ERK) 1/2. TNF production was determined by an L929 bioassay, and stress fiber polymerization was evaluated by confocal microscopy. Preconditioning of macrophages with NaCl or mannitol resulted in dose-dependent reduction in ERK 1/2 phosphorylation with no effect on p38 phosphorylation. Urea preconditioning had no effect on either mitogen-activated protein kinase. A dose-dependent attenuation of TNF production was seen with NaCl and mannitol preconditioning (p < 0.05), but not with urea. NaCl and mannitol preconditioning resulted in failure of LPS-induced stress fiber polymerization, whereas urea did not. Extracellular hypertonic conditions (i.e., NaCl and mannitol) have an immunomodulatory effect on macrophages, demonstrated through failure of optimal stress fiber polymerization, ERK 1/2 activity, and TNF production. Intracellular hypertonic conditions (i.e., urea) had no significant effect. Hypertonic saline or mannitol resuscitation, therefore, may help protect against multiple-organ dysfunction syndrome as a result of this reduced proinflammatory responsiveness.