OBJECTIVE Previously we demonstrated the neuroprotective effect of 5-lipoxygenase(5-LOX)inhibitor as well as cysteinyl leukotriene receptor 1(Cys LT1)antagoniston rotenone-induced microglial activation and neuronal de...OBJECTIVE Previously we demonstrated the neuroprotective effect of 5-lipoxygenase(5-LOX)inhibitor as well as cysteinyl leukotriene receptor 1(Cys LT1)antagoniston rotenone-induced microglial activation and neuronal death.In this study,we determined the effects of 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast on neurotoxicity induced by 1-methyl-4-phenylpyridine(MPP+)in an in vitro model of Parkinson disease(PD).METHODS The neurotoxicity of MPP+,a neurotoxin relevant to PD,on the PC12 cells was measured by MTT assay,lactate dehydrogenase(LDH)release and double fluorescence staining with Hoechst/propidiumiodide(PI).The protective effects of 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast were investigated by the above methods.RESULTS We found that exposure of PC12 cells to MPP+led to a reduced cell viability and an increased level of LDH in a concentration-dependent manner.Pretreatment with zileuton and montelukast significantly attenuated viability loss and LDH release in MPP+-treated PC12 cells.Furthermore,MPP+increasednecrotic cell death in PC12 cells.Administration of montelukast significantly decreased MPP+-induced cell necrosis in PC12 cells.CONCLUSION The 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast have a neuroprotective effects on MPP+-induced neurotoxicity in PC12 cells.The 5-LOX inhibitor and Cys LT1 antagonist might raise a possibility as potential therapeutic agent for PD and other inflammation-related the central nervous system disorders.展开更多
Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in th...Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in the pathological progression of cerebral ischemia and neurodegenerative diseases including Parkinson disease(PD).Therefore,it is important to find effective therapeutic targets to attenuate inflammation and delay the progression of brain injury.Cysteinyl leukotrienes(CysLTs) are potent inflammatory mediators synthesized from arachidonic acid by 5-lipoxygenase(5-LOX) in the central nervous system.Two distinct G-protein-coupled receptors,CysLT1 R and CysLT2 R,mediate most of the known CysLTs biological responses.Accumulating evidence has demonstrated that postischemic inflammation and neuronal loss are mediated by 5-LOX and CysLTRs fol owing focal cerebral ischemia.We recently reported that the expression of 5-LOX,CysLT1R and inflammatory vascular cell adhesion molecule-1(VCAM-1) was upregulated in the hippocampus of rats with transient global cerebral ischemia,which was closely associated with delayed neuronal death in the hippocampal CA1 area.5-LOX inhibitor zileuton,CysLT1R antagonist ONO-1078 and montelukast dose-dependently reduced hippocampal CA1 neuronal death and inhibited the increased expression of 5-LOX and VCAM-1.In vitro ischemia-like injury in 5-LOXtransfected PC12 cells,oxygen-glucose deprivation(OGD) induced cell death mediated by5-LOX via ROS/P38 MAPK pathway.The nonselective 5-LOX inhibitor caffeic acid inhibited OGDstimulated activation of 5-LOX and ROS/P38 MAPK signaling and improved neuronal survival.In PD model,high concentrations of rotenone caused directly PC12 neurotoxicity,which was modulated by 5-LOX and abolished by suppression of 5-LOX.It is well known that microglia is major modulators of inflammatory response after brain injury.Overactivated microglia and production of proinflammatory cytokine IL-1β,IL-6 and TNF-α contribute to the neuroinflammation and brain injury.5-LOX,CysLT1R and CysLT2R are involved in microglial activation and resultant neurotoxic responses.It has been found that low concentrations of rotenone can activate 5-LOX and CysLT1R on microglial cells to enhance microglial inflammation and microglia-dependent neuronal death in vitro.5-LOX inhibitor zileuton and CysLT1R antagonist montelukast protected neurons from microglia-dependent rotenone neurotoxicity.Furthermore,lipopolysaccharide(LPS)induced microglial activation and microglial neurotoxicity mediated by CysLT2R in vitro.Both pharmacological blockade(CysLT2R antagonist HAMI3379) and RNA interference(specific short hairpin RNA) of CysLT2 R significantly attenuated LPS-triggered microglial inflammation and subsequent neuronal death.Collectively,the present results indicate the role of 5-LOX and CysLTRs in neuroinflammation and brain injury.Modulation of 5-LOX and CysLTRs may be potential therapeutic approaches for inflammation-related brain disorders such as cerebral ischemia and PD.However,further research is needed to clarify the mechanisms underlying the regulation of neuinflammatory processes by 5-LOX and CysLTRs.展开更多
OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine micr...OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine microglial morphological changes and the upstream molecular underlying IL^(-1)β production in Cys LT receptor agonist leukotriene D4(LTD4)-treated BV2 microglia in vitro.METHODS Twenty-four hours after murine microglial BV2 cells were stimulated with LTD4(1-100 nmol·L^(-1)),the cell proliferation and morphology were observed.The expression level of cysteinyl aspartate-specific protease 1(CASP1) protein was measured by Western blotin BV2 cells.In addition,BV2 cells were pretreated with or without CysLT1 receptor antagonist montelukast for 1 h and the effects of monte-lukaston LTD4-stimulated microglial activation and CASP1 expression were evaluated.RESULTS The number of BV2 cells had an increasing tendency after 24 h treatment with LTD4,but no significant differences were observed between the control and LTD4-treated cells(P>0.05).Under basal and resting conditions,BV2 microglial cells displayed a ramified morphology.However,LTD4 at 100 nmool·L^(-1) drove microglial morphological changes from a ramified towards an amoeboid shape.The expression of CASP1 protein was significantly upregulated in 100 nmool·L^(-1) LTD4-treated BV2 microglia(P<0.01).Furthermore,pretreatment with CysLT1 receptor antagonist montelukast prevented cell morphological changes and suppressed the increased CASP1 expression in LTD4-treated BV2 cells(P<0.05).CONCLUSION Cys LT receptor agonist LTD4 induces morphological changes and CASP1 expressionin BV2 microglia,which can be inhibited by CysLT1 antagonist.These results suggest the involvement of Cys LT signaling in microglial morphological changes and CASP1 expression.展开更多
基金The project supported National Natural Science Foundation of China(81273491)the Zhejiang Provincial Natural Science Foundation(LY12H31010)
文摘OBJECTIVE Previously we demonstrated the neuroprotective effect of 5-lipoxygenase(5-LOX)inhibitor as well as cysteinyl leukotriene receptor 1(Cys LT1)antagoniston rotenone-induced microglial activation and neuronal death.In this study,we determined the effects of 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast on neurotoxicity induced by 1-methyl-4-phenylpyridine(MPP+)in an in vitro model of Parkinson disease(PD).METHODS The neurotoxicity of MPP+,a neurotoxin relevant to PD,on the PC12 cells was measured by MTT assay,lactate dehydrogenase(LDH)release and double fluorescence staining with Hoechst/propidiumiodide(PI).The protective effects of 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast were investigated by the above methods.RESULTS We found that exposure of PC12 cells to MPP+led to a reduced cell viability and an increased level of LDH in a concentration-dependent manner.Pretreatment with zileuton and montelukast significantly attenuated viability loss and LDH release in MPP+-treated PC12 cells.Furthermore,MPP+increasednecrotic cell death in PC12 cells.Administration of montelukast significantly decreased MPP+-induced cell necrosis in PC12 cells.CONCLUSION The 5-LOX inhibitor zileuton and Cys LT1 antagonist montelukast have a neuroprotective effects on MPP+-induced neurotoxicity in PC12 cells.The 5-LOX inhibitor and Cys LT1 antagonist might raise a possibility as potential therapeutic agent for PD and other inflammation-related the central nervous system disorders.
基金The project supported by National Natural Science Foundation of China(81671188)Zhejiang Provincial Natural Science Foundation of China(LY12H31010)Key Laboratory of Hangzhou City Project(20090233T12)
文摘Brian ischemic injury and central neurodegenerative diseases as leading contributors to disability and death have become a majorclinical and public health concern worldwide.Neuroinflammation plays a pivotal role in the pathological progression of cerebral ischemia and neurodegenerative diseases including Parkinson disease(PD).Therefore,it is important to find effective therapeutic targets to attenuate inflammation and delay the progression of brain injury.Cysteinyl leukotrienes(CysLTs) are potent inflammatory mediators synthesized from arachidonic acid by 5-lipoxygenase(5-LOX) in the central nervous system.Two distinct G-protein-coupled receptors,CysLT1 R and CysLT2 R,mediate most of the known CysLTs biological responses.Accumulating evidence has demonstrated that postischemic inflammation and neuronal loss are mediated by 5-LOX and CysLTRs fol owing focal cerebral ischemia.We recently reported that the expression of 5-LOX,CysLT1R and inflammatory vascular cell adhesion molecule-1(VCAM-1) was upregulated in the hippocampus of rats with transient global cerebral ischemia,which was closely associated with delayed neuronal death in the hippocampal CA1 area.5-LOX inhibitor zileuton,CysLT1R antagonist ONO-1078 and montelukast dose-dependently reduced hippocampal CA1 neuronal death and inhibited the increased expression of 5-LOX and VCAM-1.In vitro ischemia-like injury in 5-LOXtransfected PC12 cells,oxygen-glucose deprivation(OGD) induced cell death mediated by5-LOX via ROS/P38 MAPK pathway.The nonselective 5-LOX inhibitor caffeic acid inhibited OGDstimulated activation of 5-LOX and ROS/P38 MAPK signaling and improved neuronal survival.In PD model,high concentrations of rotenone caused directly PC12 neurotoxicity,which was modulated by 5-LOX and abolished by suppression of 5-LOX.It is well known that microglia is major modulators of inflammatory response after brain injury.Overactivated microglia and production of proinflammatory cytokine IL-1β,IL-6 and TNF-α contribute to the neuroinflammation and brain injury.5-LOX,CysLT1R and CysLT2R are involved in microglial activation and resultant neurotoxic responses.It has been found that low concentrations of rotenone can activate 5-LOX and CysLT1R on microglial cells to enhance microglial inflammation and microglia-dependent neuronal death in vitro.5-LOX inhibitor zileuton and CysLT1R antagonist montelukast protected neurons from microglia-dependent rotenone neurotoxicity.Furthermore,lipopolysaccharide(LPS)induced microglial activation and microglial neurotoxicity mediated by CysLT2R in vitro.Both pharmacological blockade(CysLT2R antagonist HAMI3379) and RNA interference(specific short hairpin RNA) of CysLT2 R significantly attenuated LPS-triggered microglial inflammation and subsequent neuronal death.Collectively,the present results indicate the role of 5-LOX and CysLTRs in neuroinflammation and brain injury.Modulation of 5-LOX and CysLTRs may be potential therapeutic approaches for inflammation-related brain disorders such as cerebral ischemia and PD.However,further research is needed to clarify the mechanisms underlying the regulation of neuinflammatory processes by 5-LOX and CysLTRs.
基金supported by National Natural Science Foundation of China(81671188)Zhejiang Provincial Natural Science Foundation of China(LY12H31010)the Key Laboratory of Hangzhou City Project(20090233T12)
文摘OBJECTIVE We have recently reported that cysteinyl leukotriene(Cys LT) signaling plays an important role in microglial interleukin(IL)-1β secretion and subsequent neurotoxicity.The present study aimed to examine microglial morphological changes and the upstream molecular underlying IL^(-1)β production in Cys LT receptor agonist leukotriene D4(LTD4)-treated BV2 microglia in vitro.METHODS Twenty-four hours after murine microglial BV2 cells were stimulated with LTD4(1-100 nmol·L^(-1)),the cell proliferation and morphology were observed.The expression level of cysteinyl aspartate-specific protease 1(CASP1) protein was measured by Western blotin BV2 cells.In addition,BV2 cells were pretreated with or without CysLT1 receptor antagonist montelukast for 1 h and the effects of monte-lukaston LTD4-stimulated microglial activation and CASP1 expression were evaluated.RESULTS The number of BV2 cells had an increasing tendency after 24 h treatment with LTD4,but no significant differences were observed between the control and LTD4-treated cells(P>0.05).Under basal and resting conditions,BV2 microglial cells displayed a ramified morphology.However,LTD4 at 100 nmool·L^(-1) drove microglial morphological changes from a ramified towards an amoeboid shape.The expression of CASP1 protein was significantly upregulated in 100 nmool·L^(-1) LTD4-treated BV2 microglia(P<0.01).Furthermore,pretreatment with CysLT1 receptor antagonist montelukast prevented cell morphological changes and suppressed the increased CASP1 expression in LTD4-treated BV2 cells(P<0.05).CONCLUSION Cys LT receptor agonist LTD4 induces morphological changes and CASP1 expressionin BV2 microglia,which can be inhibited by CysLT1 antagonist.These results suggest the involvement of Cys LT signaling in microglial morphological changes and CASP1 expression.
