Ciesla D J, Moore E E, Musters R J, Biffl W L, Silliman C A
Department of Surgery, Denver Health Medical Center, 777 Bannock Street, Denver, CO 80204, USA.
J Trauma. 2001 Feb;50(2):206-12. doi: 10.1097/00005373-200102000-00004.
Recognition that hypertonic saline (HTS) modulates the inflammatory response has renewed interest in this agent for postinjury resuscitation. Changes in extracellular tonicity alter cell shape and are accompanied by cytoskeletal reorganization. Recent evidence suggests that cytoskeletal reorganization is critical for receptor-mediated signal transduction. We hypothesized that HTS-induced changes in the cytoskeleton interfere with cytotoxic signal transduction.
Isolated neutrophils (PMNs) were incubated in HTS (Na+ = 180 mmol/L) and activated with N-formyl-methionyl-leucyl-phenylalanine (receptor-mediated) or phorbol myristate (receptor independent). Actin polymerization was assessed by digital image microscopy and flow cytometry. PMN superoxide anion (O2-) production and p38 MAPK activation was measured by reduction of cytochrome c and Western blot. Pretreatment with cytochalasin B was used to disrupt HTS-induced actin reorganization.
HTS inhibited receptor-mediated cytoskeletal reorganization and attenuated p38 MAPK activation and O2- production. HTS had no effect on receptor-independent O2- production. Cytoskeletal disruption (cytochalasin B) prevented HTS attenuation of receptor-mediated p38 MAPK activation.
HTS attenuates the PMN cytotoxic response by interfering with intracellular signal transduction. Changes in the actin cytoskeleton appear to modulate receptor-mediated p38 MAPK signaling.
高渗盐水（HTS）可调节炎症反应，这一认识重新激发了人们对其用于伤后复苏的兴趣。细胞外张力的变化会改变细胞形状，并伴有细胞骨架重组。最近的证据表明，细胞骨架重组对于受体介导的信号转导至关重要。我们推测，HTS诱导的细胞骨架变化会干扰细胞毒性信号转导。
将分离的中性粒细胞（PMN）置于HTS（Na⁺ = 180 mmol/L）中，并分别用N-甲酰甲硫氨酰-亮氨酰-苯丙氨酸（受体介导）或佛波酯（受体非依赖性）激活。通过数字图像显微镜和流式细胞术评估肌动蛋白聚合。通过细胞色素c还原和蛋白质印迹法测量PMN超氧阴离子（O₂⁻）产生和p38丝裂原活化蛋白激酶（MAPK）激活。用细胞松弛素B预处理以破坏HTS诱导的肌动蛋白重组。
HTS抑制受体介导的细胞骨架重组，并减弱p38 MAPK激活和O₂⁻产生。HTS对受体非依赖性O₂⁻产生无影响。细胞骨架破坏（细胞松弛素B）可防止HTS减弱受体介导的p38 MAPK激活。
HTS通过干扰细胞内信号转导减弱PMN细胞毒性反应。肌动蛋白细胞骨架的变化似乎调节受体介导的p38 MAPK信号传导。
