Activation of p38 MAPKα by extracellular pressure mediates the stimulation of macrophage phagocytosis by pressure
Activation of p38 MAPKα by extracellular pressure mediates the stimulation of macrophage phagocytosis by pressure
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DOI：
10.1152/ajpcell.00543.2004
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发表时间：
2005-05-01
影响因子：
5.5
通讯作者：
Basson, MD
中科院分区：
文献类型：
--
作者：
Shiratsuchi, H;Basson, MD
我们以前已经证明，恒定的20毫米汞柱的细胞外压力增加血清调理乳胶珠吞噬佛波醇12-肉豆蔻酸酯13-乙酸酯（PMA）分化的THP-1巨噬细胞的部分抑制粘着斑激酶（FAK）和细胞外信号调节激酶（ERK）。由于p38 MAPK在其他细胞中被物理力激活，我们假设p38 MAPK的调节也可能有助于通过压力刺激巨噬细胞吞噬。我们研究了PMA分化的THP-1巨噬细胞、原代人单核细胞和人单核细胞衍生的巨噬细胞（MDM）的吞噬作用。使用SB-203580或通过p38 MAPK α小干扰RNA（siRNA）抑制p38 MAPK活化。压力增加了原代单核细胞和MDM中的吞噬作用，如在THP-1细胞中一样。在DMSO处理的THP-1巨噬细胞中，增加细胞外压30分钟使磷酸化p38 MAPK增加46.4 +/- 20.5%，在原代单核细胞中增加20.9 +/- 9%（P < 0.05）。SB-203580（20 μ M）使THP-1巨噬细胞中基础p38 MAPK磷酸化降低34.7 +/- 2.1%，并阻止p38的压力激活。p38 MAPK alpha siRNA使总p38 MAPK蛋白减少50- 60%。SB-203580在THP-1细胞和外周血单核细胞，也没有p38 MAPK siRNA在THP-1细胞影响基础吞噬，但每个取消压力刺激的吞噬。SB-203580不影响THP-1巨噬细胞中的基础或压力降低的FAK活化，但显著减弱了与压力相关的ERK磷酸化的降低。p38 MAPK α siRNA使总FAK蛋白减少40- 50%，总ERK减少10- 15%，但使磷酸化ERK增加1.4 +/-0.1倍。p38 MAPK alpha siRNA转染不影响压力对FAK-Y397磷酸化的抑制，但阻止了ERK磷酸化的抑制。感染或炎症期间细胞外压的变化通过对p38 MAPK α的FAK依赖性反向作用调节巨噬细胞吞噬作用，该作用随后可能下调ERK。
We have previously demonstrated that constant 20 mmHg extracellular pressure increases serum-opsonized latex bead phagocytosis by phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 macrophages in part by inhibiting focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK). Because p38 MAPK is activated by physical forces in other cells, we hypothesized that modulation of p38 MAPK might also contribute to the stimulation of macrophage phagocytosis by pressure. We studied phagocytosis in PMA-differentiated THP-1 macrophages, primary human monocytes, and human monocyte-derived macrophages (MDM). p38 MAPK activation was inhibited using SB-203580 or by p38 MAPK alpha small interfering RNA (siRNA). Pressure increased phagocytosis in primary monocytes and MDM as in THP-1 cells. Increased extracellular pressure for 30 min increased phosphorylated p38 MAPK by 46.4 +/- 20.5% in DMSO-treated THP-1 macrophages and by 20.9 +/- 9% in primary monocytes (P < 0.05 each). SB-203580 (20 mu M) reduced basal p38 MAPK phosphorylation by 34.7 +/- 2.1% in THP-1 macrophages and prevented pressure activation of p38. p38 MAPK alpha siRNA reduced total p38 MAPK protein by 50-60%. Neither SB-203580 in THP-1 cells and peripheral monocytes nor p38 MAPK siRNA in THP-1 cells affected basal phagocytosis, but each abolished pressure-stimulated phagocytosis. SB-203580 did not affect basal or pressure-reduced FAK activation in THP-1 macrophages, but significantly attenuated the reduction in ERK phosphorylation associated with pressure. p38 MAPK alpha siRNA reduced total FAK protein by 40-50%, and total ERK by 10-15%, but increased phosphorylated ERK 1.4 +/- 0.1-fold. p38 MAPK alpha siRNA transfection did not affect the inhibition of FAK-Y397 phosphorylation by pressure but prevented inhibition of ERK phosphorylation. Changes in extracellular pressure during infection or inflammation regulate macrophage phagocytosis by a FAK-dependent inverse effect on p38 MAPK alpha that might subsequently downregulate ERK.