Variants of the arachidonate 5-1ipoxygenase-activating protein （ALOX5AP） gene have been suggested to play an important role in the pathogenesis of atherosclerosis and ischemic stroke. This study was aimed to explore...Variants of the arachidonate 5-1ipoxygenase-activating protein （ALOX5AP） gene have been suggested to play an important role in the pathogenesis of atherosclerosis and ischemic stroke. This study was aimed to explore the association of ALOX5AP variants with ischemic stroke risk in Han Chinese of eastern China. A total of 690 ischemic stroke cases and 767 controls were recruited. The subjects were further subtyped according to the Trial of Org 10172 in Acute Stroke Treatment （TOAST） criteria. On the basis of that, two polymorphisms of the ALOX5AP gene （rs10507391 and rs12429692） were determined by TaqMan genotyping assay. In addition, plasma leukotriene B4 （LTB4） levels were analyzed in these subjects. There was no evidence of association between the two variants of ALOX5AP and the risk of ischemic stroke or its TOAST-subtypes. Haplotype analysis and stratification analysis according to sex, age, body mass index, hypertension, and diabetes also showed negative association. Analysis of LTB4 levels in a subset of cases and controls revealed that LTB4 levels were significantly higher in ischemic stroke cases than in the controls （70.06± 14.75 ng/L vs 57.34±10.93 ng/L; P = 0.000） and carriers of the T allele of the rs10507391 variant were associated with higher plasma LTB4 levels （P = 0.000）. The present study suggests there is no association of the two polymorphisms in the ALOX5AP gene with ischemic stroke risk in Han Chinese of eastern China.展开更多
The interplay between inflammation and cancer progression is a growing area of research. A combination of clinical, epidemiological, and basic science investigations indicate that there is a relationship between infla...The interplay between inflammation and cancer progression is a growing area of research. A combination of clinical, epidemiological, and basic science investigations indicate that there is a relationship between inflammatory changes in the pancreas and neoplastic progression. Diets high in ω-6 polyunsaturated fatty acids provide increased substrate for arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) to form eicosanoids. These eicosanoids directly contribute to pancreatic cancer cell proliferation. Both COX-2 and 5-LOX are upregulated in multiple cancer types, including pancreatic cancer. In vitro studies using pancreatic cancer cell lines have demonstrated upregulation of COX-2 and 5-LOX at both the mRNA and protein levels. When COX-2 and 5-LOX are blocked via a variety of mechanisms, cancer cell proliferation is abrogated both in vitro and in vivo. The mechanism of COX-2 has been shown to include effects on apoptosis as well as angiogenesis. 5-LOX has been implicated in apoptosis. The use of COX-2 and 5-LOX inhibitors in clinical studies in patients with pancreatic cancer has been limited. Patient enrollment has been restricted to those with advanced disease which makes evaluation of these drugs as chemopreventive agents difficult. COX-2 and 5-LOX expression have been shown to be present during the early neoplastic changes of pancreatic cancer, well before progression to invasive disease. This indicates that the ideal role for these interventions is early in the disease process as preventive agents, perhaps in patients with chronic pancreatitis or hereditary pancreatitis.展开更多
AIM: To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis. METHODS: The relative quantity of 5-Lo...AIM: To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis. METHODS: The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods. RESULTS: There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392, P = 0.0002), depth or vessel invasion. CONCLUSION: These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.展开更多
The inhibitors of 5-LOX control the overproduction of pro-inflammatory mediators known as leukotrienes(LTs)and thus have therapeutic relevance in the treatment of various diseases like asthma,rheumatoid arthritis,infl...The inhibitors of 5-LOX control the overproduction of pro-inflammatory mediators known as leukotrienes(LTs)and thus have therapeutic relevance in the treatment of various diseases like asthma,rheumatoid arthritis,inflammatory bowel disease and certain types of cancers.This has increased the search for efficient therapeutic agents for protein 5-LOX and this process is now primarily based on QSAR.In this study,we have developed four different quantitative structure and 5-LOX inhibition activity relationship models of benzoquinone derivative by exploiting CoMFA,RF,SVM,and MLR chemometric methods.Performance of the QSAR models was measured by using cross-validation technique as well as through the external test set prediction.RF model outperforms all other models.SVM and MLR models failed due to the poor performance of the external test set prediction.CoMFA model,which shows relatively good performance was used to explore the essential structural regions where the modification was necessary to design a novel scaffold with improved activity.Moreover,molecular docking of all the derivatives to the binding site of 5-LOX was done to show their binding mode and to identify critical interacting residues inside the active site of 5-LOX.The docking result confirms the stability and rationality of the CoMFA model.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 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
Objective:To explore the potential mechanism of lysionotin in treating glioma.Methods:First,target prediction based on Bernoulli Naïve Bayes profiling and pathway enrichment was used to predict the biological act...Objective:To explore the potential mechanism of lysionotin in treating glioma.Methods:First,target prediction based on Bernoulli Naïve Bayes profiling and pathway enrichment was used to predict the biological activity of lysionotin.The binding between 5-lipoxygenase(5-LO)and lysionotin was detected by surface plasmon resonance(SPR)and molecular docking,and the inhibitory effects of lysionotin on 5-LO and proliferation of glioma were determined using enzyme inhibition assay in vitro and cell viability analysis,respectively.Furthermore,the pharmaceutical effect of lysionotin was explored by cell survival rate analysis and liquid chromatography with tandem mass spectrometry(LC-MS/MS).The protein expression,intracellular calcium ion concentration and cytoskeleton detection were revealed by Western blot,flow cytometry and fluorescence labeling,respectively.Results:Target prediction and pathway enrichment revealed that lysionotin inhibited 5-LO,a key enzyme involved in the arachidonic acid metabolism pathway,to inhibit the proliferation of glioma.Molecular docking results demonstrated that 5-LO can be binding to lysionotin through hydrogen bonds,forming bonds with His600,Gln557,Asn554,and His372.SPR analysis further confirmed the interaction between 5-LO and lysionotin.Furthermore,enzyme inhibition assay in vitro and cell survival rate analysis revealed that 50%inhibition concentration of lysionotin and the median effective concentration of lysionotin were 90 and 16.58µmol/L,respectively,and the results of LC-MS/MS showed that lysionotin inhibited the production of 5S-hydroperoxy-eicosatetraenoic acid(P<0.05),and moreover,the LC-MS/MS results indicated that lysionotin can enter glioma cells well(P<0.01)and inhibit their proliferation.Western blot analysis demonstrated that lysionotin can inhibit the expression of 5-LO(P<0.05)and downstream leukotriene B4 receptor(P<0.01).In addition,the results showed that lysionotin affected intracellular calcium ion concentration by inhibiting 5-LO to affect the cytoskeleton,as determined by flow cytometry and fluorescence labeling.Conclusion:Lysionotin binds to 5-LO could suppress glioma by inhibiting arachiodonic acid metabolism pathway.展开更多
It is suggested that Δ6 fatty acid desaturase(FAD) plays a critical role in the biosynthesis of polyunsaturated fatty acids in plants and microalgae. But why does it adapt to the changed environments such as nitrogen...It is suggested that Δ6 fatty acid desaturase(FAD) plays a critical role in the biosynthesis of polyunsaturated fatty acids in plants and microalgae. But why does it adapt to the changed environments such as nitrogen starvation is seldom understood. One Δ6 FAD gene( MiD6 fad) from an arachidonic acidrich microalga M yrmecia incisa Reisigl(Chlorophyta) was first heterologously expressed in S accharomyces cerevisiae for the identification of function. The fatty acid profile of transgenic yeast detected by gas chromatography-mass spectrometry illustrated that the enzyme MiD6 FAD could convert linoleic and ?-linolenic acids to γ-linolenic and stearidonic acids, respectively, demonstrating that M iD6 fad encoded a Δ6 FAD. A 1 965-bp fragment of the cloned 2 347-bp 5′-upstream region of M iD6 fad was next subcloned and fused upstream with green fluorescent protein(GFP) gene to replace the GAL1 promoter of the vector pYES2. The generated construct was transformed into S. cerevisiae for function determination. Confocal microscopic images of the transformed line illustrated that this inserted fragment could drive GFP expression, which was further verified by fluorescence intensity quantification and Western blot analysis using antiGFP antibody. The conversion efficiency(approximately 2%-3%) of MiD6 FAD was much lower than the reported ? 3 FAD and Δ6 elongase in this microalga, suggesting that MiD6 FAD catalysed the possible ratelimiting step for ArA biosynthesis. The presence of several putative c is-acting regulatory elements in this identified promoter sheds new light on the regulation mechanism research of Δ6 FAD transcription for the ArA production in M. incisa in changing environmental factors.展开更多
基金supported by a grant from the Health Bureau of Jiangsu Province (No. H201005)
文摘Variants of the arachidonate 5-1ipoxygenase-activating protein （ALOX5AP） gene have been suggested to play an important role in the pathogenesis of atherosclerosis and ischemic stroke. This study was aimed to explore the association of ALOX5AP variants with ischemic stroke risk in Han Chinese of eastern China. A total of 690 ischemic stroke cases and 767 controls were recruited. The subjects were further subtyped according to the Trial of Org 10172 in Acute Stroke Treatment （TOAST） criteria. On the basis of that, two polymorphisms of the ALOX5AP gene （rs10507391 and rs12429692） were determined by TaqMan genotyping assay. In addition, plasma leukotriene B4 （LTB4） levels were analyzed in these subjects. There was no evidence of association between the two variants of ALOX5AP and the risk of ischemic stroke or its TOAST-subtypes. Haplotype analysis and stratification analysis according to sex, age, body mass index, hypertension, and diabetes also showed negative association. Analysis of LTB4 levels in a subset of cases and controls revealed that LTB4 levels were significantly higher in ischemic stroke cases than in the controls （70.06± 14.75 ng/L vs 57.34±10.93 ng/L; P = 0.000） and carriers of the T allele of the rs10507391 variant were associated with higher plasma LTB4 levels （P = 0.000）. The present study suggests there is no association of the two polymorphisms in the ALOX5AP gene with ischemic stroke risk in Han Chinese of eastern China.
文摘The interplay between inflammation and cancer progression is a growing area of research. A combination of clinical, epidemiological, and basic science investigations indicate that there is a relationship between inflammatory changes in the pancreas and neoplastic progression. Diets high in ω-6 polyunsaturated fatty acids provide increased substrate for arachidonic acid metabolism by cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) to form eicosanoids. These eicosanoids directly contribute to pancreatic cancer cell proliferation. Both COX-2 and 5-LOX are upregulated in multiple cancer types, including pancreatic cancer. In vitro studies using pancreatic cancer cell lines have demonstrated upregulation of COX-2 and 5-LOX at both the mRNA and protein levels. When COX-2 and 5-LOX are blocked via a variety of mechanisms, cancer cell proliferation is abrogated both in vitro and in vivo. The mechanism of COX-2 has been shown to include effects on apoptosis as well as angiogenesis. 5-LOX has been implicated in apoptosis. The use of COX-2 and 5-LOX inhibitors in clinical studies in patients with pancreatic cancer has been limited. Patient enrollment has been restricted to those with advanced disease which makes evaluation of these drugs as chemopreventive agents difficult. COX-2 and 5-LOX expression have been shown to be present during the early neoplastic changes of pancreatic cancer, well before progression to invasive disease. This indicates that the ideal role for these interventions is early in the disease process as preventive agents, perhaps in patients with chronic pancreatitis or hereditary pancreatitis.
文摘AIM: To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis. METHODS: The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods. RESULTS: There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392, P = 0.0002), depth or vessel invasion. CONCLUSION: These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.
文摘The inhibitors of 5-LOX control the overproduction of pro-inflammatory mediators known as leukotrienes(LTs)and thus have therapeutic relevance in the treatment of various diseases like asthma,rheumatoid arthritis,inflammatory bowel disease and certain types of cancers.This has increased the search for efficient therapeutic agents for protein 5-LOX and this process is now primarily based on QSAR.In this study,we have developed four different quantitative structure and 5-LOX inhibition activity relationship models of benzoquinone derivative by exploiting CoMFA,RF,SVM,and MLR chemometric methods.Performance of the QSAR models was measured by using cross-validation technique as well as through the external test set prediction.RF model outperforms all other models.SVM and MLR models failed due to the poor performance of the external test set prediction.CoMFA model,which shows relatively good performance was used to explore the essential structural regions where the modification was necessary to design a novel scaffold with improved activity.Moreover,molecular docking of all the derivatives to the binding site of 5-LOX was done to show their binding mode and to identify critical interacting residues inside the active site of 5-LOX.The docking result confirms the stability and rationality of the CoMFA model.
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Supported by the Natural Science Foundation of China(No.81473369)the National Key Research and Development Program of China(No.2017YFC1702703)Jinan City Science and Technology SMES Innovation Ability Improvement Project,“Traditional Chinese Medicine Digital Humanities Youth Innovation Team”of College and University in Shandong Province(No.2023RW093)。
文摘Objective:To explore the potential mechanism of lysionotin in treating glioma.Methods:First,target prediction based on Bernoulli Naïve Bayes profiling and pathway enrichment was used to predict the biological activity of lysionotin.The binding between 5-lipoxygenase(5-LO)and lysionotin was detected by surface plasmon resonance(SPR)and molecular docking,and the inhibitory effects of lysionotin on 5-LO and proliferation of glioma were determined using enzyme inhibition assay in vitro and cell viability analysis,respectively.Furthermore,the pharmaceutical effect of lysionotin was explored by cell survival rate analysis and liquid chromatography with tandem mass spectrometry(LC-MS/MS).The protein expression,intracellular calcium ion concentration and cytoskeleton detection were revealed by Western blot,flow cytometry and fluorescence labeling,respectively.Results:Target prediction and pathway enrichment revealed that lysionotin inhibited 5-LO,a key enzyme involved in the arachidonic acid metabolism pathway,to inhibit the proliferation of glioma.Molecular docking results demonstrated that 5-LO can be binding to lysionotin through hydrogen bonds,forming bonds with His600,Gln557,Asn554,and His372.SPR analysis further confirmed the interaction between 5-LO and lysionotin.Furthermore,enzyme inhibition assay in vitro and cell survival rate analysis revealed that 50%inhibition concentration of lysionotin and the median effective concentration of lysionotin were 90 and 16.58µmol/L,respectively,and the results of LC-MS/MS showed that lysionotin inhibited the production of 5S-hydroperoxy-eicosatetraenoic acid(P<0.05),and moreover,the LC-MS/MS results indicated that lysionotin can enter glioma cells well(P<0.01)and inhibit their proliferation.Western blot analysis demonstrated that lysionotin can inhibit the expression of 5-LO(P<0.05)and downstream leukotriene B4 receptor(P<0.01).In addition,the results showed that lysionotin affected intracellular calcium ion concentration by inhibiting 5-LO to affect the cytoskeleton,as determined by flow cytometry and fluorescence labeling.Conclusion:Lysionotin binds to 5-LO could suppress glioma by inhibiting arachiodonic acid metabolism pathway.
基金Supported by the National Natural Science Foundation of China(No.31172389)the Special Project of Marine Renewable Energy from the State Oceanic Administration(No.SHME2011SW02)the Shanghai Universities Peak Discipline Project of Aquaculture
文摘It is suggested that Δ6 fatty acid desaturase(FAD) plays a critical role in the biosynthesis of polyunsaturated fatty acids in plants and microalgae. But why does it adapt to the changed environments such as nitrogen starvation is seldom understood. One Δ6 FAD gene( MiD6 fad) from an arachidonic acidrich microalga M yrmecia incisa Reisigl(Chlorophyta) was first heterologously expressed in S accharomyces cerevisiae for the identification of function. The fatty acid profile of transgenic yeast detected by gas chromatography-mass spectrometry illustrated that the enzyme MiD6 FAD could convert linoleic and ?-linolenic acids to γ-linolenic and stearidonic acids, respectively, demonstrating that M iD6 fad encoded a Δ6 FAD. A 1 965-bp fragment of the cloned 2 347-bp 5′-upstream region of M iD6 fad was next subcloned and fused upstream with green fluorescent protein(GFP) gene to replace the GAL1 promoter of the vector pYES2. The generated construct was transformed into S. cerevisiae for function determination. Confocal microscopic images of the transformed line illustrated that this inserted fragment could drive GFP expression, which was further verified by fluorescence intensity quantification and Western blot analysis using antiGFP antibody. The conversion efficiency(approximately 2%-3%) of MiD6 FAD was much lower than the reported ? 3 FAD and Δ6 elongase in this microalga, suggesting that MiD6 FAD catalysed the possible ratelimiting step for ArA biosynthesis. The presence of several putative c is-acting regulatory elements in this identified promoter sheds new light on the regulation mechanism research of Δ6 FAD transcription for the ArA production in M. incisa in changing environmental factors.
