Attenuation of shock-induced acute lung injury by sphingosine kinase inhibition
Attenuation of shock-induced acute lung injury by sphingosine kinase inhibition
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DOI：
10.1097/01.ta.0000149495.44582.76
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发表时间：
2004-11-01
影响因子：
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通讯作者：
Hauser, CJ
中科院分区：
文献类型：
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作者：
Lee, C;Xu, DZ;Hauser, CJ
背景资料：细胞溶质钙浓度（[Ca 2 +]（i））的长期升高是中性粒细胞（PMN）对G蛋白偶联化学引诱物的最佳激活反应所必需的。我们最近发现，耦合内体钙池耗尽更长时间的外部进入钙依赖于细胞转化鞘氨醇鞘氨醇1-磷酸（SIP）的鞘氨醇激酶（SK）。因此，我们推测，抑制SK可能会抑制中性粒细胞活化，从而改善创伤和失血性休克（T/HS）后的肺损伤。方法：采用改良的Boyden小室，在有或无选择性SK抑制剂SKI-2的情况下，研究人中性粒细胞的趋化性（CTX）。在测定抑制人PMN CTX 50%的SKI-2浓度（IC 50）后，我们对大鼠进行T/HS（剖腹手术，出血至30-40 mm Hg x 90分钟，3小时复苏）。然后，我们研究了大鼠中性粒细胞CD 11b的表达使用流式细胞术和肺损伤使用伊文思蓝染料技术在存在的IC 50剂量的SKI-2或车辆给予预处理剖腹手术。结果：40 μ mol/L SKI-2对人PMN CTX的抑制率略高于50%（233 +/- 20 vs 103 12 × 10（3）细胞/孔，p < 0.001）。在存在30 mumol/L SKI-2的情况下，T/HS后大鼠PMN的CD 11b表达从352 +/- 30降至232 +/- 7 MFU（p < 0.001）。肺对伊文思蓝的渗透性从9.5 +/- 2降低至4.1 +/- 0.7%（p = 0.036）。SKI-2没有引起血流动力学不稳定或改变复苏要求。结论：通过SK抑制调节PMN Ca 2+内流在体外抑制PMN CTX，并在体内抑制CD 11b表达，而对血流动力学没有重大影响。这些细胞变化与T/HS大鼠模型中体内肺损伤的改善有关。这些发现表明，SK抑制可通过控制[Ca 2 +]（i）调节炎症，而不会出现Ca 2+通道阻滞预期的心血管损害。因此，SK抑制似乎是一个重要的新的候选治疗休克后的炎症器官损伤。
Background: Prolonged elevations of cytosolic calcium concentrations ([Ca2+](i)) are required for optimal neutrophil (PMN) activation responses to G-Protein coupled chemoattractants. We recently showed that the coupling of endosomal Ca2+ store depletion to more prolonged entry of external Ca2+ depends on cellular conversion of sphingosine to sphingosine 1-phosphate (SIP) by sphingosine kinase (SK). We therefore hypothesized that inhibition of SK might inhibit PMN activation and thus ameliorate lung injury after trauma and hemorrhagic shock (T/HS). Methods: Chemotaxis (CTX) of human PMN was studied using modified Boyden chambers in the presence or absence of the selective SK inhibitor, SKI-2. After determining the concentration of SKI-2 that inhibited human PMN CTX by 50% (IC50) we subjected rats to T/HS (laparotomy, hemorrhage to 30-40 mm Hg x 90 minutes, 3 hours resuscitation). We then studied rat PMN CD11b expression using flow cytometry and lung injury using the Evans Blue dye technique in the presence of IC50 doses of SKI-2 or vehicle given in pretreatment at laparotomy. Resultd: Human PMN CTX was suppressed slightly more than 50% by 40 mumol/L SKI-2 (233 +/- 20 vs 103 12x 10(3) cells/well, p < 0.001). Rat PMN expression of CD11b after T/HS was decreased from 352 +/- 30 to 232 +/- 7 MFU (p < 0.001) in the presence 30 mumol/L SKI-2. Lung permeability to Evans Blue was decreased from 9.5 +/- 2 to 4.1 +/- 0.7% (p = 0.036.). SKI-2 did not cause hemodynamic instability or alter resuscitation requirements. Conclusion: Modulation of PMN Ca2+ entry via SK inhibition inhibits PMN CTX in vitro, and inhibits CD11b expression in vivo without major effects on hemodynamics. These cellular changes were associated with amelioration of lung injury in vivo in a rat model of T/HS. These findings suggest that SK inhibition allows modulation of inflammation via control of [Ca2+](i) without the cardiovascular compromise expected with Ca2+ channel blockade. SK inhibition therefore appears to be an important novel candidate therapy for inflammatory organ injury after shock.