Kan Wen-Hong, Hsu Jun-Te, Schwacha Martin G, Choudhry Mashkoor A, Bland Kirby I, Chaudry Irshad H
Department of Surgery, Center for Surgical Research, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA.
Ann Surg. 2008 Aug;248(2):294-302. doi: 10.1097/SLA.0b013e318180a3db.
In this study, we tested the hypothesis that 17beta-estradiol (E2) administration after trauma-hemorrhage reduces lung injury through a mechanism involving estrogen receptor (ER)-dependent activation of the endothelial nitric oxide (NO) synthase (eNOS)/protein kinase G (PKG)/vasodilator-stimulated phosphoprotein (VASP) pathway.
Estrogen provides protection after injury via activation of multiple signaling cascades, including the cyclic GMP-dependent PKG pathway. Phosphorylation of VASP at Ser239 (p-VASP) can be used to assess PKG signaling activity.
Male Sprague-Dawley rats (275-325 g) underwent soft tissue trauma (midline laparotomy) and hemorrhagic shock (mean blood pressure 35-40 mm Hg for 90 minutes) followed by fluid resuscitation. Animals were pretreated with a nonselective NOS inhibitor (N(omega)-nitro-L-arginine methyl ester; 30 mg/kg), a soluble guanylyl cyclase (sGC) inhibitor [1H-(1, 2, 4) oxadiazolo (3, 4-alpha) quinoxalin-1-one; 10 mg/kg] or an ER antagonist (ICI 182,780; 3 mg/kg) 30 minutes before E2 (100 microg/kg) or vehicle administration. Animals were killed at 2 hours after resuscitation.
Lung injury induced by trauma-hemorrhage is evidenced by edema (wet/dry ratio), neutrophil infiltration (myeloperoxidase activity), and with an increased expression of cytokines, chemokines, and adhesion molecules. E2 treatment after trauma-hemorrhage resulted in an increase in eNOS expression/phosphorylation, PKG-I activation, and VASP/p-VASP expression, which paralleled a decrease in lung injury. Inhibition of NOS and sGC abolished the E2-induced increase in PKG-I activity, VASP/p-VASP expression. Blockade of eNOS, PKG-I, and ER exacerbated lung inflammation and injury.
These results collectively suggest that activation of the eNOS-PKG/VASP pathway by E2 protects against trauma-hemorrhage-induced lung injury.
在本研究中，我们验证了以下假说：创伤性出血后给予17β-雌二醇（E2）可通过涉及雌激素受体（ER）依赖性激活内皮型一氧化氮合酶（eNOS）/蛋白激酶G（PKG）/血管舒张刺激磷蛋白（VASP）途径的机制减轻肺损伤。
雌激素通过激活包括环鸟苷酸依赖性PKG途径在内的多种信号级联反应在损伤后提供保护作用。VASP在Ser239位点的磷酸化（p-VASP）可用于评估PKG信号活性。
雄性Sprague-Dawley大鼠（275 - 325 g）接受软组织创伤（中线剖腹术）和失血性休克（平均血压35 - 40 mmHg，持续90分钟），随后进行液体复苏。在给予E2（100 μg/kg）或溶剂前30分钟，动物分别用非选择性NOS抑制剂（Nω-硝基-L-精氨酸甲酯；30 mg/kg）、可溶性鸟苷酸环化酶（sGC）抑制剂[1H-(1,2,4)恶二唑并(3,4-α)喹喔啉-1-酮；10 mg/kg]或ER拮抗剂（ICI 182,780；3 mg/kg）进行预处理。复苏后2小时处死动物。
创伤性出血所致的肺损伤表现为水肿（湿/干比值）、中性粒细胞浸润（髓过氧化物酶活性）以及细胞因子、趋化因子和黏附分子表达增加。创伤性出血后给予E2导致eNOS表达/磷酸化增加、PKG-I激活以及VASP/p-VASP表达增加，同时肺损伤减轻。抑制NOS和sGC消除了E2诱导的PKG-I活性和VASP/p-VASP表达增加。阻断eNOS、PKG-I和ER会加重肺部炎症和损伤。
这些结果共同表明，E2激活eNOS-PKG/VASP途径可预防创伤性出血诱导的肺损伤。
