[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Method...[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Methods]Chlorogenic acid was extracted from hon-eysuckle by ultrasound assisted alcohol extraction method.Seventy mice were randomly divided into normal group,model group,and low,me-dium and high dose groups of honeysuckle chlorogenic acid.All the mice in each group except for the normal group were given maltol aluminum by intraperitoneal injection to establish models of aluminum induced AD,continuously injected for 5 d and stopped for 2 d,totally poisoned for 8 weeks.Starting from the 5^(th) week of poisoning,the low,medium and high dose groups of honeysuckle chlorogenic acid were given honeysuck-le chlorogenc acid solution 40,80 and 160 mg/kg by gavage,respectively,while the normal group and the model group were fed with an equal volume of distilled water,all once daily,continuously gavaged until the end of the 8^(th) week.At the end of the experiment,the learning memory ability of the mice was tested by Y-type waler maze,and the number of tests required to reach the learning standard,the number of memory er-rors in 20 tests and the error rate of the mice were recorded.The brains of mice were taken to determine the contents of β-secretase,α-secre-tase,γ-secretase,LXA4 and acetylcholinesterase(AchE)in the homogenates of brain tissues by ELISA,and their blood was taken to deter-mine the biochemical indexes.[Results]Compared with the normal group,the number of learning tests,number of memory errors,error rate and the contents of β-secretase,γ-secretase and AchE in brain tissue of the mice in the model group were all significantly increased(all P<0.05),the contents of LXA4 in brain tissue were significantly decreased(all P<0.05),and the contents of α-secretase did not change significantly(all P>0.05);compared with the model group,the number of learning tests,the number of memory errors,the error rate and the content of β-secretase,γ-secretase and AchE in brain tissue were all significantly reduced(all P<0.05),the content of LXA4 in brain tissue of the high dose group of honeysuckle chlorogenic acid was significantly increased(P<0.05),and there was no significant change in the content of α-secretase in brain tissue of all groups of honeysuckle chlorogenic acid(all P>0.05).Compared with the normal group,the levels of blood glucose,TC,TG,ALT,BUN,Cr and UA in the model group and the levels of TC,TG and BUN in the low-and medium-dose groups of honeysuckle chlorogenic acid were significantly increased(all P<0.05),and the level of HDL-C in the model group and the levels of UA in the medium-and high-dose groups of honeysuckle chlorogenic acid were significantly decreased(all P<0.05);compared with the model group,the levels of blood glucose,ALT,BUN,UA in each group of honeysuckle chlorogenic acid,the levels of TC and Cr in medium and high dose groups of honeysuckle chlorogenic acid,and the level of TG in the high dose group of honeysuckle chlorogenic acid were all signifi-cantly lower(all P<0.05),while the level of HDL-C in the medium and high dose groups of honeysuckle chlorogenic acid and the level of to-tal protein in the high dose group of honeysuckle chlorogenic acid were all significantly higher(all P<0.05).[Conclusions]Chlorogenic acid from honeysuckle may improve AD induced by aluminum exposure via regulating related secretory enzymes,LXA4,and various biochemi-cal indicators.展开更多
Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize t...Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize the OsLOX1 gene from rice seeds, the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a（＋） and transformed into Escherichia coil BL21 （DE3）. Expression of the fusion protein was successfully induced by isopropyl-β-D- thiogalactopyranoside （IPTG） and the purified recombinant protein was obtained by His.Bind Kits. Further assay showed that the purified recombinant protein exhibited the LOX activity. The optimum pH was 4.8 （acetate buffer） and the optimum temperature was 30℃ for the above enzyme. Thus, the recombinant might confer an available usage for the synthesis of jasmonate in vitro, and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.展开更多
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
Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an i...Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.展开更多
A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lya...A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lyase （PAL）, a rate-limiting enzyme of phenyl- propanoid pathway, were measured in the leaves of one-year-old poplar （Populus simonii × P. pyramidalis ＇Opera 8277＇） cuttings after Clostera anachoreta larvae attack. The results show that the increased activities of LOX and PAL were found not only in the leaves wounded by C. anachoreta larvae but also in their tipper systemic leaves, indicating that JA and phenylpropanoid pathways were activated, and the defense response was stimulated systemically. The increase in LOX and PAL activities in neighboring intact poplar cuttings sug- gested that there exists the interplant communication between poplar plants mediated by the herbivore-induced volatiles. Methyl jasmonate （MeJA） was also proved to be an airborne signal to induce defense response in P simonii × P pyramidalis ＇Opera 8277＇ cuttings.展开更多
130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analy...130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.展开更多
Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells...Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells, and have been implicated in diabetic peripheral neuropathy. In our recent studies, leukocytetype 12/15-lipoxygenase inhibition or gene deficiency alleviated large and small nerve fiber dysfunction, but not intraepidermal nerve fiber loss in streptozotocin-diabetic mice. Methods: To address a mechanism we evaluated the potential for pharmacological 12/15-lipoxygenase inhibition to counteract excessive MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy. C57Bl6/J mice were made diabetic with streptozotocin and maintained with or without the 12/15-lipoxygenase inhibitor cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC). Human Schwann cells were cultured in5.5 mMor30 mMglucose with or without CDC. Results: 12(S) HETE concentrations (ELISA), as well as 12/15-lipoxygenase expression and p38 MAPK, ERK, and SAPK/JNK phosphorylation (all by Western blot analysis) were increased in the peripheral nerve and spinal cord of diabetic mice as well as in high glucose-exposed human Schwann cells. CDC counteracted diabetes-induced increase in 12(S)HETE concentrations (a measure of 12/15-lipoxygenase activity), but not 12/15-lipoxygenase overexpression, in sciatic nerve and spinal cord. The inhibitor blunted excessive p38 MAPK and ERK, but not SAPK/ JNK, phosphorylation in sciatic nerve and high glucose exposed human Schwann cells, but did not affect MAPK, ERK, and SAPK/JNK phosphorylation in spinal cord. Conclusion: 12/15-lipoxygenase inhibition counteracts diabetes related MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy and implies that 12/15-lipoxygenase inhibitors may be an effective treatment for diabetic peripheral neuropathy.展开更多
The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC...The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC) and gas chromatography-mass spectrometry. Results showed that the same 24 flavor constituents were isolated in both soymilk and soyflour, and most of them were aldehydes and alcohols. Lox2 was most responsible for the production of the volatile and beany-flavor components, and Lox1 less responsible. Lox3 was least responsible and can reduce the yield of hexanal. Either Lx1 or Lx2 could significantly reduce the volatile and beany-flavor, and Lx3 could significantly increase the yield of hexanal. Primary and secondary interactions existed among the null mutant genes, and the major effects and interactions could be affected by processing conditions. The isoline with triple lipoxygenase null genes yielded the least volatile and beany-flavor components, and the isoline without the lipoxygenase gene Lx3 produced the greatest amount of the volatile and beany-flavor components. The amounts of volatile and beany-flavor components produced by the other isolines were between that of the isoline with triple lipoxygenase null genes and the isoline without lipoxygenase gene Lx3. According to the correlation analysis, the hexanal amount could be used as an index in evaluating the importance of lipoxygenase isozymes in the yield of beany-flavor compounds, and the effects of the different types of lipoxygenase null mutants in controlling beany-flavor compounds. The cultivars with triple lipoxygenase null genes will be a quality raw material for soy food processing.展开更多
Beany flavor induced by three lipoxygenases(LOXs, including LOX1, LOX2, and LOX3)restricts human consumption of soybean. It is desirable to generate lipoxygenase-free new mutant lines to improve the eating quality of ...Beany flavor induced by three lipoxygenases(LOXs, including LOX1, LOX2, and LOX3)restricts human consumption of soybean. It is desirable to generate lipoxygenase-free new mutant lines to improve the eating quality of soybean oil and protein products. In this study, a pooled clustered regularly interspaced short palindromic repeats(CRISPR)-CRISPRassociated protein 9(Cas9) strategy targeting three GmLox genes(GmLox1, GmLox2, and GmLox3) was applied and 60 T_0 positive transgenic plants were generated, carrying combinations of sg RNAs and mutations. Among them, GmLox-28 and GmLox-60 were gmlox1 gmlox2 gmlox3 triple mutants and GmLox-40 was a gmlox1 gmlox2 double mutant.Sequencing of T_1 mutant plants derived from GmLox-28, GmLox-60, and GmLox-40 showed that mutation in the GmLox gene was inherited by the next generation. Colorimetric assay revealed that plants carrying different combinations of mutations lost the corresponding lipoxygenase activities. Transgene-free mutants were obtained by screening the T_2 generation of lipoxygenase-free mutant lines(GmLox-28 and GmLox-60). These transgeneand lipoxygenase-free mutants could be used for soybean beany flavor reduction without restriction by regulatory frameworks governing transgenic organisms.展开更多
Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening p...Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.展开更多
BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHO...BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHODS:Expression of 12-LOX was assessed in a diethylnitrosamine-induced rat HCC model,and in SMMC-7721,HepG2 and L-02 cells using immunohistochemical staining and reverse transcriptase-polymerase chain reaction(RT-PCR).GST-π and Ki-67 were determined in vivo by immunohistochemical staining.Apoptosis was evaluated by TUNEL assay.Cell viability and apoptosis were determined by MTT assay and flow cytometry,respectively.Apoptosis-related proteins in SMMC-7721 and HepG2 cells were detected by Western blotting.RESULTS:Immunohistochemical staining and RT-PCR showed that 12-LOX was over-expressed in rat HCC and two HCC cell lines,while the expression was inhibited by baicalein,a specific inhibitor of 12-LOX.Baicalein inhibited cell proliferation and induced apoptosis in rat HCC and both cell lines in a dose-and time-dependent manner.Our in vivo study demonstrated that baicalein also reduced neoplastic nodules.Mechanistically,baicalein reduced Bcl-2 protein expression coupled with a slight increase of the expression of Bax and activation of caspase-3.Furthermore,baicalein inhibited the activation of ERK-1/2(phosphorylated).Interestingly,the effects of baicalein were reversed by 12(S)-HETE,a metabolite of 12-LOX.CONCLUSIONS:Inhibition of 12-LOX leads to reduced numbers of HCC cells,partially caused by increased apoptosis.12-LOX may be a potential molecular target for HCC prevention and treatment.展开更多
基金Supported by Baise Science Research and Technology Development Plan Project(20232022)Cuangxi College Students’Innovation and Entrepreneurship Training Program(Recommend National Level2022210599040S).
文摘[Objectives]To explore the effects of chlorogenic acid from honeysuckle on the secretion enzymes,lipoxygenase A4(LXA4),and blood biochemical indicators in mice with aluminum induced Alzheimer's disease(AD).[Methods]Chlorogenic acid was extracted from hon-eysuckle by ultrasound assisted alcohol extraction method.Seventy mice were randomly divided into normal group,model group,and low,me-dium and high dose groups of honeysuckle chlorogenic acid.All the mice in each group except for the normal group were given maltol aluminum by intraperitoneal injection to establish models of aluminum induced AD,continuously injected for 5 d and stopped for 2 d,totally poisoned for 8 weeks.Starting from the 5^(th) week of poisoning,the low,medium and high dose groups of honeysuckle chlorogenic acid were given honeysuck-le chlorogenc acid solution 40,80 and 160 mg/kg by gavage,respectively,while the normal group and the model group were fed with an equal volume of distilled water,all once daily,continuously gavaged until the end of the 8^(th) week.At the end of the experiment,the learning memory ability of the mice was tested by Y-type waler maze,and the number of tests required to reach the learning standard,the number of memory er-rors in 20 tests and the error rate of the mice were recorded.The brains of mice were taken to determine the contents of β-secretase,α-secre-tase,γ-secretase,LXA4 and acetylcholinesterase(AchE)in the homogenates of brain tissues by ELISA,and their blood was taken to deter-mine the biochemical indexes.[Results]Compared with the normal group,the number of learning tests,number of memory errors,error rate and the contents of β-secretase,γ-secretase and AchE in brain tissue of the mice in the model group were all significantly increased(all P<0.05),the contents of LXA4 in brain tissue were significantly decreased(all P<0.05),and the contents of α-secretase did not change significantly(all P>0.05);compared with the model group,the number of learning tests,the number of memory errors,the error rate and the content of β-secretase,γ-secretase and AchE in brain tissue were all significantly reduced(all P<0.05),the content of LXA4 in brain tissue of the high dose group of honeysuckle chlorogenic acid was significantly increased(P<0.05),and there was no significant change in the content of α-secretase in brain tissue of all groups of honeysuckle chlorogenic acid(all P>0.05).Compared with the normal group,the levels of blood glucose,TC,TG,ALT,BUN,Cr and UA in the model group and the levels of TC,TG and BUN in the low-and medium-dose groups of honeysuckle chlorogenic acid were significantly increased(all P<0.05),and the level of HDL-C in the model group and the levels of UA in the medium-and high-dose groups of honeysuckle chlorogenic acid were significantly decreased(all P<0.05);compared with the model group,the levels of blood glucose,ALT,BUN,UA in each group of honeysuckle chlorogenic acid,the levels of TC and Cr in medium and high dose groups of honeysuckle chlorogenic acid,and the level of TG in the high dose group of honeysuckle chlorogenic acid were all signifi-cantly lower(all P<0.05),while the level of HDL-C in the medium and high dose groups of honeysuckle chlorogenic acid and the level of to-tal protein in the high dose group of honeysuckle chlorogenic acid were all significantly higher(all P<0.05).[Conclusions]Chlorogenic acid from honeysuckle may improve AD induced by aluminum exposure via regulating related secretory enzymes,LXA4,and various biochemi-cal indicators.
基金grants from the National Basic Research Program of China (Grant No. 2004CB2117204)the National High-tech Research and Development Program of China (Grant No. 2006AA100101)+1 种基金the National Program of Science Technology and Tackle Key Problem of Chinathe Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) of China
文摘Lipoxygenase （LOX, EC1.13.11.12） is a key enzyme during the degradation of lipids in animals and even plants, and also the first key enzyme responsible for the biosynthesis of jasmonate. To purify and characterize the OsLOX1 gene from rice seeds, the entire coding region of the OsLOX1 gene was inserted into an expression vector pET30a（＋） and transformed into Escherichia coil BL21 （DE3）. Expression of the fusion protein was successfully induced by isopropyl-β-D- thiogalactopyranoside （IPTG） and the purified recombinant protein was obtained by His.Bind Kits. Further assay showed that the purified recombinant protein exhibited the LOX activity. The optimum pH was 4.8 （acetate buffer） and the optimum temperature was 30℃ for the above enzyme. Thus, the recombinant might confer an available usage for the synthesis of jasmonate in vitro, and also provides a possibility for elucidating the inter-relationship between the primary structure of the plant seed lipoxygenase protein and its physiological functions.
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.
基金supported by the National Natural Science Foundation of China(Grant Nos.32202542 and U20A2045)the Project of Major Science and Technology in Anhui Province(Grant No.202003a06020021)+2 种基金the Project of Science and Technology of Yunnan Province(Grant No.202102AE090038)Anhui Provincial Natural Science Foundation(Grant No.2108085QC121)the Natural Science Projects for Colleges and Universities in the Anhui Province(Grant No.KJ2021A0145)。
文摘Osmotic stress caused by low-temperature,drought and salinity was a prevalent abiotic stress in plant that severely inhibited plant development and agricultural yield,particularly in tea plant.Jasmonic acid(JA)is an important phytohormone involving in plant stress.However,underlying molecular mechanisms of JA modulated osmotic stress response remains unclear.In this study,high concentration of mannitol induced JA accumulation and increase of peroxidase activity in tea plant.Integrated transcriptome mined a JA signaling master,MYC2 transcription factor is shown as a hub regulator that induced by mannitol,expression of which positively correlated with JA biosynthetic genes(LOX and AOS)and peroxidase genes(PER).CsMYC2 was determined as a nuclei-localized transcription activator,furthermore,ProteinDNA interaction analysis indicated that CsMYC2 was positive regulator that activated the transcription of CsLOX7,CsAOS2,CsPER1 and CsPER3via bound with their promoters,respectively.Suppression of CsMYC2 expression resulted in a reduced JA content and peroxidase activity and osmotic stress tolerance of tea plant.Overexpression of CsMYC2 in Arabidopsis improved JA content,peroxidase activity and plants tolerance against mannitol stress.Together,we proposed a positive feedback loop mediated by CsMYC2,CsLOX7 and CsAOS2 which constituted to increase the tolerance of osmotic stress through fine-tuning the accumulation of JA levels and increase of POD activity in tea plant.
基金supported by the Pro-gramme for Changjiang Scholars and the Innovative Research Team in Universities of China (PCSIRT0607)by the National Natural Science Foundation of China (30871727+2 种基金 30872037)the National Key Project of Scientific and Technical Supporting Programmes Funded by the Ministry of Science & Technology of China (2006BAD01A15 2006BAD24B04)
文摘A study was conducted to explore the defense response in woody plants after insect herbivory. The activities of two enzymes, lipoxygenase （LOX）, a key enzyme ofjasmonate （JA） pathway, and phenylalanine ammonia lyase （PAL）, a rate-limiting enzyme of phenyl- propanoid pathway, were measured in the leaves of one-year-old poplar （Populus simonii × P. pyramidalis ＇Opera 8277＇） cuttings after Clostera anachoreta larvae attack. The results show that the increased activities of LOX and PAL were found not only in the leaves wounded by C. anachoreta larvae but also in their tipper systemic leaves, indicating that JA and phenylpropanoid pathways were activated, and the defense response was stimulated systemically. The increase in LOX and PAL activities in neighboring intact poplar cuttings sug- gested that there exists the interplant communication between poplar plants mediated by the herbivore-induced volatiles. Methyl jasmonate （MeJA） was also proved to be an airborne signal to induce defense response in P simonii × P pyramidalis ＇Opera 8277＇ cuttings.
基金Supported by the National Natural Science Foundation of China(NO:31371615)National Key Research&Developing Plan(2016YFD0300405)the National Natural Science Foundation of Anhui Province(1608085MC70)~~
文摘130 wheat varieties are selected as materials to test the LOX activity, whiteness, yellowness, carotenoids content and RVA parameters, which are to be analyzed by variance analysis, correlation analysis, cluster analysis and classified according to the origins. The result shows there are highly significant variations in LOX activity from varieties; LOX activity is positively correlated with whiteness, and significantly and negatively correlated with yellowness. Cluster analysis applying longest distance method based on LOX activity clusters all the varieties or lines into three major groups. There are great differences between the averages of LOX activity from varieties. LOX activities are discussed in the application of nutritional quality improvement in wheat.
文摘Background: Increased mitogen-activated protein kinase (MAPK) phosphorylation has been detected in peripheral nerve of human subjects and animal models with diabetes as well as high-glucose exposed human Schwann cells, and have been implicated in diabetic peripheral neuropathy. In our recent studies, leukocytetype 12/15-lipoxygenase inhibition or gene deficiency alleviated large and small nerve fiber dysfunction, but not intraepidermal nerve fiber loss in streptozotocin-diabetic mice. Methods: To address a mechanism we evaluated the potential for pharmacological 12/15-lipoxygenase inhibition to counteract excessive MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy. C57Bl6/J mice were made diabetic with streptozotocin and maintained with or without the 12/15-lipoxygenase inhibitor cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC). Human Schwann cells were cultured in5.5 mMor30 mMglucose with or without CDC. Results: 12(S) HETE concentrations (ELISA), as well as 12/15-lipoxygenase expression and p38 MAPK, ERK, and SAPK/JNK phosphorylation (all by Western blot analysis) were increased in the peripheral nerve and spinal cord of diabetic mice as well as in high glucose-exposed human Schwann cells. CDC counteracted diabetes-induced increase in 12(S)HETE concentrations (a measure of 12/15-lipoxygenase activity), but not 12/15-lipoxygenase overexpression, in sciatic nerve and spinal cord. The inhibitor blunted excessive p38 MAPK and ERK, but not SAPK/ JNK, phosphorylation in sciatic nerve and high glucose exposed human Schwann cells, but did not affect MAPK, ERK, and SAPK/JNK phosphorylation in spinal cord. Conclusion: 12/15-lipoxygenase inhibition counteracts diabetes related MAPK phosphorylation in mouse and cell culture models of diabetic neuropathy and implies that 12/15-lipoxygenase inhibitors may be an effective treatment for diabetic peripheral neuropathy.
文摘The flavor of the soymilk and soyflour obtained from the lipoxygenase mutant isolines was concentrated by simultaneous distillation and extraction (SDE), and its constituents were identified by gas chro-matography (GC) and gas chromatography-mass spectrometry. Results showed that the same 24 flavor constituents were isolated in both soymilk and soyflour, and most of them were aldehydes and alcohols. Lox2 was most responsible for the production of the volatile and beany-flavor components, and Lox1 less responsible. Lox3 was least responsible and can reduce the yield of hexanal. Either Lx1 or Lx2 could significantly reduce the volatile and beany-flavor, and Lx3 could significantly increase the yield of hexanal. Primary and secondary interactions existed among the null mutant genes, and the major effects and interactions could be affected by processing conditions. The isoline with triple lipoxygenase null genes yielded the least volatile and beany-flavor components, and the isoline without the lipoxygenase gene Lx3 produced the greatest amount of the volatile and beany-flavor components. The amounts of volatile and beany-flavor components produced by the other isolines were between that of the isoline with triple lipoxygenase null genes and the isoline without lipoxygenase gene Lx3. According to the correlation analysis, the hexanal amount could be used as an index in evaluating the importance of lipoxygenase isozymes in the yield of beany-flavor compounds, and the effects of the different types of lipoxygenase null mutants in controlling beany-flavor compounds. The cultivars with triple lipoxygenase null genes will be a quality raw material for soy food processing.
基金supported by funds from the National Key Research and Development Program of China(2016YFD0100700)to Y.G。
文摘Beany flavor induced by three lipoxygenases(LOXs, including LOX1, LOX2, and LOX3)restricts human consumption of soybean. It is desirable to generate lipoxygenase-free new mutant lines to improve the eating quality of soybean oil and protein products. In this study, a pooled clustered regularly interspaced short palindromic repeats(CRISPR)-CRISPRassociated protein 9(Cas9) strategy targeting three GmLox genes(GmLox1, GmLox2, and GmLox3) was applied and 60 T_0 positive transgenic plants were generated, carrying combinations of sg RNAs and mutations. Among them, GmLox-28 and GmLox-60 were gmlox1 gmlox2 gmlox3 triple mutants and GmLox-40 was a gmlox1 gmlox2 double mutant.Sequencing of T_1 mutant plants derived from GmLox-28, GmLox-60, and GmLox-40 showed that mutation in the GmLox gene was inherited by the next generation. Colorimetric assay revealed that plants carrying different combinations of mutations lost the corresponding lipoxygenase activities. Transgene-free mutants were obtained by screening the T_2 generation of lipoxygenase-free mutant lines(GmLox-28 and GmLox-60). These transgeneand lipoxygenase-free mutants could be used for soybean beany flavor reduction without restriction by regulatory frameworks governing transgenic organisms.
基金Supported by National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (No.2006BAD22B01)National Natural Science Foundation of China (No.30800767)Postdoctoral Fund of China (No.20080430725)
文摘Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.
基金supported by grants from the National Natural Science Foundation of China(81000998)the Natural Science Foundation of Hubei Province,China(2007ABA248)the Foundation of the Ministry of Education of China for New Teachers(20090141120003)
文摘BACKGROUND:12-lipoxygenase(12-LOX) has been reported to be an important gene in cancer cell proliferation and survival,and tumor metastasis.However,its role in hepatocellular carcinoma(HCC) cells remains unknown.METHODS:Expression of 12-LOX was assessed in a diethylnitrosamine-induced rat HCC model,and in SMMC-7721,HepG2 and L-02 cells using immunohistochemical staining and reverse transcriptase-polymerase chain reaction(RT-PCR).GST-π and Ki-67 were determined in vivo by immunohistochemical staining.Apoptosis was evaluated by TUNEL assay.Cell viability and apoptosis were determined by MTT assay and flow cytometry,respectively.Apoptosis-related proteins in SMMC-7721 and HepG2 cells were detected by Western blotting.RESULTS:Immunohistochemical staining and RT-PCR showed that 12-LOX was over-expressed in rat HCC and two HCC cell lines,while the expression was inhibited by baicalein,a specific inhibitor of 12-LOX.Baicalein inhibited cell proliferation and induced apoptosis in rat HCC and both cell lines in a dose-and time-dependent manner.Our in vivo study demonstrated that baicalein also reduced neoplastic nodules.Mechanistically,baicalein reduced Bcl-2 protein expression coupled with a slight increase of the expression of Bax and activation of caspase-3.Furthermore,baicalein inhibited the activation of ERK-1/2(phosphorylated).Interestingly,the effects of baicalein were reversed by 12(S)-HETE,a metabolite of 12-LOX.CONCLUSIONS:Inhibition of 12-LOX leads to reduced numbers of HCC cells,partially caused by increased apoptosis.12-LOX may be a potential molecular target for HCC prevention and treatment.
