目的观察充血性心力衰竭病人心肌重构病理过程中肿瘤抑制因子PTEN(phosphatase and tensin homolog tumor suppressor,PTEN)及丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)与蛋白激酶C(protein kinase C,PKC)的作用。方...目的观察充血性心力衰竭病人心肌重构病理过程中肿瘤抑制因子PTEN(phosphatase and tensin homolog tumor suppressor,PTEN)及丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)与蛋白激酶C(protein kinase C,PKC)的作用。方法通过手术取材,选择因瓣膜性心脏病接受二尖瓣置换术的心力衰竭病人39例,正常对照38例(其中8例来自意外伤亡的器官捐献者)。竞争蛋白结合法检测心肌组织PKC及MAPK活性,免疫沉淀法检测PTEN蛋白表达。结果心力衰竭病人心肌组织呈典型的重构心肌的病理改变。心肌组织PTEN表达蛋白光吸收(absorbance,A)与β肌动蛋白光吸收比值(PTEN/β-actin)随心功能恶化而降低,各心力衰竭组与正常组相比,差异有统计学意义(P<0.01);相反,心力衰竭病人心肌组织PKC和MAPK活性明显高于对照组(P<0.01),并随心功能恶化其表达逐渐增加,各心力衰竭组与正常组比较,差异有统计学意义(P<0.01)。结论PTEN及MAPK与PKC信号通路共同参与调节CHF病人心肌重构的病理过程,PTEN在心肌重构病理过程中起负性调节作用。展开更多
Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK...Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA2 is activated with a significant increase of the release of [ H3 ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-α and PKC-ε, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.展开更多
Fucoidan can cure both antimony-sensitive and antimony-resistant visceral leishmaniasis through immune activation. However, the signaling events underlying this cellular response remain uncharacterized. The present st...Fucoidan can cure both antimony-sensitive and antimony-resistant visceral leishmaniasis through immune activation. However, the signaling events underlying this cellular response remain uncharacterized. The present study reveals that fucoidan induces activation of p38 and ERKI/2 and NF-κB DNA binding in both normal and Leishmania donovani.infected macrophages, as revealed by western blotting and electrophoretic mobility shift assay （EMSA）, respectively. Pharmacological inhibition of p38, ERKI/2 or the NF-κB pathway markedly attenuated fucoidan-induced pro-inflammatory cytokine synthesis and inducible nitric oxide synthase （iNOS） gene transcription, resulting in a reduction of parasite clearance. To decipher the underlying mechanism of fucoidan-mediated parasite suppression, the expression and functionality of various protein kinase C （PKC） isoforms were evaluated by immunoblotting and enzyme activity assay. Fucoidan elicited an increase in expression and activity of PKC-α, -β1 and -βⅡ isoforms in infected macrophages. Functional knockdown of PKC-α and -β resulted in downregulation of p38 and ERKI/2, along with a marked reduction of IL-12 and TNF-α production in fucoidan-treated infected macrophages. Collectively, these results suggest that the curative effect of fucoidan is mediated by PKC-dependent activation of the mitogen-activated protein kinase （MAPK）/NF-κB pathway, which ultimately results in the production of nitric oxide （NO） and disease-resolving pro-inflammatory cytokines.展开更多
文摘目的观察充血性心力衰竭病人心肌重构病理过程中肿瘤抑制因子PTEN(phosphatase and tensin homolog tumor suppressor,PTEN)及丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)与蛋白激酶C(protein kinase C,PKC)的作用。方法通过手术取材,选择因瓣膜性心脏病接受二尖瓣置换术的心力衰竭病人39例,正常对照38例(其中8例来自意外伤亡的器官捐献者)。竞争蛋白结合法检测心肌组织PKC及MAPK活性,免疫沉淀法检测PTEN蛋白表达。结果心力衰竭病人心肌组织呈典型的重构心肌的病理改变。心肌组织PTEN表达蛋白光吸收(absorbance,A)与β肌动蛋白光吸收比值(PTEN/β-actin)随心功能恶化而降低,各心力衰竭组与正常组相比,差异有统计学意义(P<0.01);相反,心力衰竭病人心肌组织PKC和MAPK活性明显高于对照组(P<0.01),并随心功能恶化其表达逐渐增加,各心力衰竭组与正常组比较,差异有统计学意义(P<0.01)。结论PTEN及MAPK与PKC信号通路共同参与调节CHF病人心肌重构的病理过程,PTEN在心肌重构病理过程中起负性调节作用。
基金Project supported by the National Natural Science Foundation of China, Shanghai Joint Laboratory of Life Science, Shanghai Institute of Cell Biology, and Director's Foundations of Chinese Academy of Sciences and Shanghai Institute of Cell Biology.
文摘Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA2 is activated with a significant increase of the release of [ H3 ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-α and PKC-ε, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.
文摘Fucoidan can cure both antimony-sensitive and antimony-resistant visceral leishmaniasis through immune activation. However, the signaling events underlying this cellular response remain uncharacterized. The present study reveals that fucoidan induces activation of p38 and ERKI/2 and NF-κB DNA binding in both normal and Leishmania donovani.infected macrophages, as revealed by western blotting and electrophoretic mobility shift assay （EMSA）, respectively. Pharmacological inhibition of p38, ERKI/2 or the NF-κB pathway markedly attenuated fucoidan-induced pro-inflammatory cytokine synthesis and inducible nitric oxide synthase （iNOS） gene transcription, resulting in a reduction of parasite clearance. To decipher the underlying mechanism of fucoidan-mediated parasite suppression, the expression and functionality of various protein kinase C （PKC） isoforms were evaluated by immunoblotting and enzyme activity assay. Fucoidan elicited an increase in expression and activity of PKC-α, -β1 and -βⅡ isoforms in infected macrophages. Functional knockdown of PKC-α and -β resulted in downregulation of p38 and ERKI/2, along with a marked reduction of IL-12 and TNF-α production in fucoidan-treated infected macrophages. Collectively, these results suggest that the curative effect of fucoidan is mediated by PKC-dependent activation of the mitogen-activated protein kinase （MAPK）/NF-κB pathway, which ultimately results in the production of nitric oxide （NO） and disease-resolving pro-inflammatory cytokines.
