The atrial natriuretic peptide and cGMP: Novel activators of the heat shock response in rat livers
The atrial natriuretic peptide and cGMP: Novel activators of the heat shock response in rat livers
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DOI：
10.1053/jhep.2002.30080
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发表时间：
2002-01-01
期刊：
影响因子：
13.5
通讯作者：
Vollmar, AM
中科院分区：
文献类型：
--
作者：
Kiemer, AK;Gerbes, AL;Vollmar, AM
心钠素(ANP)通过环鸟苷(CGMP)减轻大鼠肝脏缺血再灌注损伤。核因子kappaB(NFkappaB)的减弱激活似乎与这一效应有关。这项研究的目的是确定热休克蛋白是否参与了这些分子途径。雄性SD大鼠肝脏持续灌流Krebs-Henseleit(KH)缓冲液，分别加或不加ANP或8-Br-cGMP。在不同的实验中，肝脏分别灌流ANP或不加ANP 20分钟，在冷藏液中保存24小时，然后再灌流。用凝胶迁移率改变分析法检测冻存肝组织中热休克转录因子(HSF)、热休克蛋白70(HSP70)和磷酸甘油醛脱氢酶(GAPDHmRNA)的表达，用Western印迹法检测HSP70的表达。在持续灌流过程中，ANP和8-BR-cGMP激活HSF时，HSP70蛋白浓度与HSF激活水平平行。ANP处理的肝脏在缺血24小时后HSF升高，再灌流期间HSP70 mRNA水平升高。ANP可阻止HSP70蛋白在再灌流过程中的显著下降。免疫共沉淀研究表明，在ANP处理的肝脏中，HSP70与抑制因子kappaB(I KappaB)的结合增加。总之，我们证明了cGMP介导的ANP对HSF的激活，导致HSP70的mRNA和蛋白浓度升高，并与HSP70与I kappaB的结合增强相关。这可能是ANP介导的预防肝脏保存损伤的重要机制之一。
Preischemic treatment with atrial natriuretic peptide (ANP) attenuates ischemia-reperfusion injury of the rat liver via cyclic guanosine monophosphate (cGMP). The attenuated activation of nuclear factor kappaB (NF-kappaB) seems to contribute to this effect. The aim of this study was to determine whether heat shock proteins are involved in these molecular pathways. Livers of male Sprague-Dawley rats were continuously perfused with Krebs-Henseleit (KH) buffer with or without ANP or 8-Br-cGMP. In different experiments livers were perfused with or without ANP for 20 minutes, kept in cold storage solution for 24 hours, and reperfused. Activation of heat shock transcription factor (HSF) (by electrophoretic mobility shift assay), heat shock protein 70 (HSP70), and glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA (by reverse transcription polymerase chain reaction [RT-PCR]), as well as HSP70 (by Western blot) were investigated in freeze-clamped liver samples. During continuous perfusion ANP as well as 8-Br-cGMP activated HSF, HSP70 protein concentrations paralleled HSF-activation. ANP pretreated livers exhibited elevated HSF after 24 hours of ischemia and elevated HSP70 mRNA levels during reperfusion. ANP prevented the marked decrease of HSP70 protein during reperfusion. Coimmunoprecipitation studies showed increased binding of HSP70 to inhibitory factor kappaB (I kappaB) in ANP-treated livers. In conclusion, we showed the cGMP-mediated activation of HSF by ANP, which resulted in elevated HSP70 mRNA and protein concentrations and correlated with enhanced binding of HSP70 to I kappaB. This could be an important mechanism of ANP-mediated prevention of hepatic preservation damage.