The gonads of sea urchins(Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid(ARA, 20:4 n-6) and eicosapentaenoic acid(EPA, 20:5 n-3). However, to our knowledge, little information is ...The gonads of sea urchins(Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid(ARA, 20:4 n-6) and eicosapentaenoic acid(EPA, 20:5 n-3). However, to our knowledge, little information is available regarding the physiological response of adult sea urchins to dietary ARA. In the present study, four dietary feeds were formulated with graded ARA(0, 0.5%, 1%, and 2% dry diet). Each diet was randomly allocated to three cages during a 56-day feeding experiment. The results showed that the sea urchin weight gain rate(WGR) and the gonadosomatic index(GI) significantly increased as ARA was equal to or above 1.0% of dry diet(P < 0.05). The activities of superoxide dismutase(SOD), catalase(CAT), and total anti-oxidative capacity(T-AOC) were the highest in the coelomic fluid of sea urchins that were fed diets with 1% ARA. The total essential amino acid(TEAA) and its ratio to total non-essential amino acid(TNEAA) showed a similar tendency to WGR and GI as dietary ARA increased, and the highest TEAA and TEAA/TNEAA were observed in the gonads of sea urchins that were fed diets with 1% ARA. Levels of ARA and ARA/EPA of the gonads increased while n-3/n-6 polyunsaturated fatty acid(PUFA) decreased with the increase of dietary ARA(P < 0.05). EPA in the gonads of experimental animals fed with formulated feeds showed no significant differences(P> 0.05), but was significantly lower than those fed with kelp(P < 0.05). These results suggested that relatively higher levels of ARA(1% dry diet) significantly promoted growth, gonad development, activities of antioxidant enzymes, as well as nutritional values(TEAA, TEAA/TNEAA, and PUFA) of adult S. intermedius.展开更多
A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast reg...A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast regeneration mutagenesis. The results showed that a commixture enzyme (cellulase and glusulase) at the concentration of 4%, enzymolysis temperature at 30℃ and enzymolysis time on 7.5 h were the optimal conditions, in which the lethality of M. isabellina spores was 78.4%. After mutagenesis and re-screenings, M. isabellina mutant Y-69 was obtained. GC analysis showed that the yield of arachidonic acid by Y-69 (2.92 g. L-1) was 3.56 times higher than that of the wild-type strain (0.82 g.L-1). Pass generation tests showed that the properties of Y-69 by mutation were readily inherited.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
Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effe...Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effects of free docosahexaenoic acid (DHA), an essential brain polyunsaturated fatty acid (PUFA), on the inhibition of Aβ1-42 fibrillation by fluorescence correlation spectroscopy (FCS), a technique capable of detecting molecular movements and interactions in solution. We also examined whether free arachidonic acid (AA), eicosapentaenoic acid (EPA), and metabolites of DHA, including neuroprotectin D1 (NPD1, 10S, 17S-dihydroxy-DHA), resolvin D1 (RvD1, 7S, 8R, 17S-trihydroxy-DHA), and didocosahexaenoyl glycerol (diDHA), affect Aβ1-42 polymerization. The results of the FCS study reveal that DHA and AA significantly reduced the diffusion time of TAMRA (5-carboxytetramethylrhoda-mine)-Aβ1-42 by 28% and 31%, respectively, while EPA, NPD1, RvD1, and diDHA had no effects on diffusion time. These results indicate that DHA and AA inhibited Aβ1-42 polymerization and that their inhibitory effects occurred at the initial stage of Aβ1-42 polymerization. This study will advance the research on PUFAs in preventing AD progression.展开更多
Arachidonic acid (AA or ARA), an essential to-6 polyunsaturated fatty acid (PUFA), can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The...Arachidonic acid (AA or ARA), an essential to-6 polyunsaturated fatty acid (PUFA), can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The mutant strain of YZ-124 had the highest ARA of 4.72 g. L-1, which was 5.5 times higher than that of the original strain 3.3410. mRNA expression level of △ 6- desaturase was determined in five different kinds of ARA-producing Mortierella isabellina after cultured for 7 days, and in the mutant strain YZ-124 over a 3-8 day time-course. In addition, the desaturase activity and ARA content were measured at the selected time points. The lowest expression of △6-desaturase was observed in the original strain and the highest expression in the mutant strain YZ-124, which increased with increasing time in culture. Furthermore, a positive correlation was observed between the expression levels of △6-desaturase and ARA content. Based on this, △6-desaturase played a significant role in ARA synthesis pathway in Mortierella isabellina.展开更多
The changes of the levels of LTC4, PGI2 and TXA2 in the liver tissue in SD rats with GaIN/LPS-induced acute liver injury was studied with radioimmunoassay (RIA). As a result,12h after the administration of GaIN/LPS, s...The changes of the levels of LTC4, PGI2 and TXA2 in the liver tissue in SD rats with GaIN/LPS-induced acute liver injury was studied with radioimmunoassay (RIA). As a result,12h after the administration of GaIN/LPS, serum AST (398±37u), ALT (565 ±43u) increased (P<0.001 ) and the concentration of TXA2 (12188±588pg/g· w· wt) in liver tissue increased sigiuficantly(p<0.001), while the content of LTC4 (9713± 3557ng/g·w·wt ) and PGI2 (1748±560 pg/g· w·wt) in liver tissue were not obviously changed(p>0.05) and the inflammatory changes of the pathological findings were observed. The improvement of serum ALT (300±168u)(p< 0.05) and AST(273±424 u) (P<0. 05) and histopathological damage was observed after the administration of diethylcarbamazine (DEC), a LTA4 synthesis inhibitor, the liver TXA2(12740±699) concentration significantly increased (P<0. 001), while the levels of LTC4 (8179±1653) and PGI2 (2320±630) were not obviously changed. Serum ALT (536±74u) and AST (416± 41u)(P> 0. 05) levels and histopathology did not change with administration of indomethacin, a cyclooxygenase inhibitor, but the liver LTC4 (12166±13027) contents increased (P<0.05 ) and TXA2 (1868±791) reduced significantly (P<0. 001). The present study suggests that arachidonic acid metabolism in rats with acute liver injury are significantly abnormal. Leukotrienes and thromboxane are important inflammatory mediators in the liver injury.展开更多
Human umbilical vein endothelial cells (HU VECs) were treated with arachidonic acid (AA). After 24 h exposure to AA, typical morphological changes of apoptosis were observed by Giemsa stain and transmission electr...Human umbilical vein endothelial cells (HU VECs) were treated with arachidonic acid (AA). After 24 h exposure to AA, typical morphological changes of apoptosis were observed by Giemsa stain and transmission electron microscopy. The apoptotic ratio in HUVECs treated with 50μmol/L, 100μmol/L and 150μmol/L AA were (20.7±3.6)%, (38.6±4.3)% and (52.5±7.5) % respectively. Contrarily, low concentration of AA (425μmol/L) exerted no influence on cell viability by MTT assay. Intracellular malondialdehyde increased significantly in a dose-dependent manner upon AA treatment and for the reduced glutathione. the opposite tendency was found Western Blots show that apoplosis triggered by AA was associated with the down-regulation of Bcl-2 expression, but not with Bax and p53. Pretreatment with 50μmol/L α-tocopherol reduced AA-induced oxidative stress and apoptosis, also inhibited the dowwregulation of Bcl-2/Bax ratio. These results suggested that high concentration of free AA could induce apoptosis in HUVECs probably via oxidative stress and down-regulation of Bcl-2.展开更多
The fatty acids of a strain of Diasporangium sp.had been analyzed by using GC-MS.The fatty acids of twenty mutants were determined.Based on these results,the producing of eicosapentaenoic acid(EPA)supposed via 18∶2,1...The fatty acids of a strain of Diasporangium sp.had been analyzed by using GC-MS.The fatty acids of twenty mutants were determined.Based on these results,the producing of eicosapentaenoic acid(EPA)supposed via 18∶2,18∶3,20∶3,20∶4 which all belong to ω-6 fatty acids.The ω-3 desaturation was undertaken at arachidonic acid(AA).In addition,mutant strains resulted in enhanced content of AA which could get two times more than initial strain,but no compact on EPA.展开更多
Cerebrovascular accident(CVA)or stroke is one of the world's leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find ef...Cerebrovascular accident(CVA)or stroke is one of the world's leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery(MCAO),mainly by clots,is the origin of most CVAs in humans.展开更多
Pancreatic ductal adenocarcinoma(PDAC)is highly heterogeneous,making its prognosis prediction difficult.The arachidonic acid(AA)cascade is involved in carcinogenesis.Therefore,the metabolic enzymes of the AA cascade c...Pancreatic ductal adenocarcinoma(PDAC)is highly heterogeneous,making its prognosis prediction difficult.The arachidonic acid(AA)cascade is involved in carcinogenesis.Therefore,the metabolic enzymes of the AA cascade consist of lipoxygenases(LOXs),phospholipase A2s(PLA2s),and cyclooxygenases(COXs)along with their metabolic products,including leukotrienes.Nevertheless,the prognostic potential of AA metabolism-associated PDAC has not been explored.Herein,the mRNA expression patterns and the matching clinical information of individuals with PDAC were abstracted from online data resources.We employed the LASSO Cox regression model to develop a multigene clinical signature in the TCGA queue.The GEO queue and the ICGC queue were employed as the validation queue.There was differential expression of a significant number of AA metabolism-associated genes(56.8%)between PDAC and neighboring nonmalignant tissues in the TCGA queue.Univariate Cox regression demonstrated that 13 of the differentially expressed genes(DEGs)were linked to overall survival(OS)(p<0.05).A 6-gene clinical signature was developed for stratifying the PDAC patients into two risk groups,with the high-risk group patients exhibiting remarkably lower OS than the low-risk group patients(p<0.001 in the TCGA data set and the ICGC queue,and p=0.001 in the GEO data set).The multivariate Cox data revealed the risk score as an independent OS predictor(HR>1,p<0.01).The receiver operating characteristic(ROC)curve verified the predictive potential of our signature.The expression and alteration of the six genes in PDAC were also validated using online databases.Functional analyses demonstrated that immune-linked cascades were enriched,and the immune status was remarkably different between the high-and low-risk groups.In summary,an AA metabolism-associated clinical gene signature can be applied for prognostic estimation in PDAC.展开更多
Cell signaling is a very complex network of biochemical reactions triggered by a huge number of stimuli coming from the external medium. The function of any single signaling component depends not only on its own struc...Cell signaling is a very complex network of biochemical reactions triggered by a huge number of stimuli coming from the external medium. The function of any single signaling component depends not only on its own structure but also on its connections with other biomolecules. During prokaryotic-eukaryotic transition, the rearrangement of cell organization in terms of diffusional compartmentalization exerts a deep change in cell signaling functional potentiality. In this review I briefly introduce an intriguing ancient relationship between pathways involved in cell responses to chemical agonists (growth factors, nutrients, hormones) as well as to mechanical forces (stretch, osmotic changes). Some biomolecules (ion channels and enzymes) act as "hubs", thanks to their ability to be directly or indirectly chemically/mechanically co-regulated. In particular calcium signaling machinery and arachidonic acid metabolism are very ancient networks, already present before eukaryotic appearance. A number of molecular "hubs", including phospholipase A2 and some calcium channels, appear tightly interconnected in a cross regulation leading to the cellular response to chemical and mechanical stimulations.展开更多
Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative ...Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). This paper mainly introduced the structure, distribution, source, physiologic healthcare function and application of AA.展开更多
A microwave irradiated palladium-catalyzed reaction of carboxylic acids and crotyl type bromides creates series of esters in good to high yields. This facile ester synthesis then is applied to make esters from arachid...A microwave irradiated palladium-catalyzed reaction of carboxylic acids and crotyl type bromides creates series of esters in good to high yields. This facile ester synthesis then is applied to make esters from arachidonic acid, salicylic acid, folic acid, and aspirin efficiently.展开更多
Objective To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino(TSDN)on the arachidonic acid pathway in monosodium urate(MSU)crystal-induced M1-polarized m...Objective To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino(TSDN)on the arachidonic acid pathway in monosodium urate(MSU)crystal-induced M1-polarized macrophages.Methods M1 polarization of RAW264.7 cells were induced by 1µg/mL lipopolysaccharide(LPS).The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN.MSU(500µg/mL)was used to induce the gouty arthritis model.Afterwards,10µg/L TSDN and 8µmol/L celecoxib,which was used as a positive control,were added to the above LPS and MSU-induced cells for 24 h.The mRNA and protein expressions of cyclooxygenase(COX)2,5-lipoxygenase(5-LOX),microsomal prostaglandin E synthase derived eicosanoids(mPGES)-1,leukotriene B(LTB)4,cytochrome P450(CYP)4A,and prostaglandin E_(2)(PGE_(2))were tested by real-time polymerase chain reaction and Western blotting,respectively.The enzyme-linked immunosorbent assay was used to test the contents of M1 markers,including inducible nitric oxid synthase(NOS)2,CD80,and CD86.Results TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2,5-LOX,CYP4A,LTB4,and PGE_(2)(P<0.01)while increased the mRNA and protein expression of mPGES-1(P<0.05 or P<0.01).TSDN could also significantly decrease the contents of NOS2,CD80,and CD86(P<0.01).Conclusion TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.展开更多
Background:Inflammatory bowel disease(IBD),comprising Crohn's disease(CD)and ulcerative colitis(UC),is a heterogeneous state of chronic intestinal inflammation.Intestinal innate immunity,including innate immune ce...Background:Inflammatory bowel disease(IBD),comprising Crohn's disease(CD)and ulcerative colitis(UC),is a heterogeneous state of chronic intestinal inflammation.Intestinal innate immunity,including innate immune cells,defends against pathogens and excessive entry of gut microbiota,while preserving immune tolerance to resident intestinal microbiota,and may be characterized by its capacity to produce a rapid and nonspecific reaction.The association between microbiota dysbiosis and the pathogenesis of IBD is complex and dynamic.When the intestinal ecosystem is in dysbiosis,the reduced abundance and diversity of intestinal gut microbiota make the host more vulnerable to the attack of exogenous and endogenous pathogenic gut microbiota.The aim of our study was to comprehensively assess the relationship between microbial populations within UC,the signaling pathways of pathogenic gut microbe therein and the inflammatory response,as well as to understand the effects of using PE&AFWE(poppy extract[Papaver nudicaule L.]and Artemisia frigida Willd.extract)on UC modulation.Methods:A UC mouse model was established by inducing SPF-grade C57BL/6 mice using dextrose sodium sulfate(DSS).Based on metagenomic sequencing to characterize the gut microbiome,the relationship between gut microbiota dysbiosis and gut microbiota was further studied using random forest and Bayesian network analysis methods,as well as histopathological analysis.Results:(1)We found that the 5 gut microbiota with the highest relative abundance of inflammatory bowel disease UC model gut microbiota were consistent with the top 5 ranked natural bacteria.There were three types of abundance changes in the model groups:increases(Chlamydiae/Proteobacteria and Deferribacteres),decreases(Firmicutes),and no significant changes(Bacteroidetes).The UC model group was significantly different from the control group,with 1308 differentially expressed species with abundance changes greater than or equal to 2-fold.(2)The proportion of the fecal flora in the UC group decreased by 37.5%in the Firmicutes and increased by 14.29%in the proportion of Proteobacteria compared to the control group before treatment.(3)The significantly enriched and increased signaling pathways screened were the'arachidonic acid metabolic pathway'and the'phagosomal pathway',which both showed a decreasing trend after drug administration.(4)Based on the causal relationship between different OTUs and the UC model/PE&AFWE administration,screening for directly relevant OTU networks,the UC group was found to directly affect OTU69,followed by a cascade of effects on OTU12,OTU121,OTU93,and OTU7,which may be the pathway of action that initiated the pathological changes in normal mice.(5)We identified a causal relationship between common differentially expressed OTUs and PE&AFWE and UC in the pre-and post-PE&AFWE-treated groups.Thereby,we learned that PE&AFWE can directly affect OTU90,after which it inhibits UC,inhibiting the activity of arachidonic acid metabolic pathway by affecting OTU118,which in turn inhibits the colonization of gut microbiota by OTU93 and OTU7.(6)Histopathological observation and scoring(HS)of the colon showed that there was a significant difference between the model group and the control group(p<0.001),and that there was a significant recovery in both the sulfasalazine(SASP)and the PE&AFWE groups after the administration of the drug(p<0.0001).Conclusion:We demonstrated causal effects and inflammatory metabolic pathways in gut microbiota dysbiosis and IBD,with five opportunistic pathogens directly contributing to IBD.PE&AFWE reduced the abundance of proteobacteria in the gut microbiota,and histopathology showed significant improvement.展开更多
Background:The clinical features of keloids consist of aberrant proliferation,secretion,differentiation and apoptosis of keloid dermis-derived fibroblasts(KFBs).Notably,the apoptosis rate of KFBs is lower than the pro...Background:The clinical features of keloids consist of aberrant proliferation,secretion,differentiation and apoptosis of keloid dermis-derived fibroblasts(KFBs).Notably,the apoptosis rate of KFBs is lower than the proliferation rate.Though the anti-fibrotic effect of adipose-derived stem cells(ADSCs)on keloids has become a hot topic of research,the exact anti-fibrotic mechanism of the paracrine effect remains unclear.This study aimed to find out how the conditioned medium of ADSCs(ADSC-CM)exerts an anti-fibrotic effect in KFBs.Methods:KFBs and ADSCs were extracted and cultured.Then,ADSC-CM was prepared.Whether ADSC-CM could inhibit KFB growth and induce apoptosis was verified by the use of a cell counting kit-8,an 5-Ethynyl-2-deoxyuridine(Edu)kit and flow cytometry.The expressions of cyclooxygenase-1(COX-1),COX-2,caspase 3 and B-cell lymphoma-2(Bcl-2)in ADSC-CM-cultured KFBs were tested by real-time PCR and western blotting.To clarify the role of COX-2 in ADSC-CM-induced KFB apoptosis,a specific COX-2 inhibitor,celecoxib,was applied to KFBs cultured in ADSC-CM.Moreover,we tested the production of arachidonic acid(AA)and prostaglandin E2(PGE2)by ELISA.Then,we established a keloid transplantation model in a nude mouse to validate the therapeutic effect in vivo.Results:The proliferation ability of KFBs cultured in ADSC-CM was found to be weakened and apoptosis was significantly increased.Caspase 3 expression was significantly upregulated and Bcl-2 was downregulated in ADSC-CM-cultured KFBs.Furthermore,ADSC-CM strikingly elevated COX-2 mRNA and protein expressions,but COX-1 expression was unaltered.COX-2 inhibitors reduced ADSC-CM-induced apoptosis.Additionally,COX-2 inhibition blocked the elevation of caspase 3 and reversed the decrease in Bcl-2 expression.ADSC-CM increased PGE2 levels by 1.5-fold and this effect was restrained by COX-2 inhibition.In the nude mouse model,expressions of AA,COX-2 and PGE2 were higher in the translated keloid tissues after ADSC-CM injection than in the controls.Conclusions:We showed activation of the COX-2/PGE2 cascade in KFBs in response to ADSC-CM.By employing a specific COX-2 inhibitor,COX-2/PGE2 cascade activation played a crucial role in mediating the ADSC-CM-induced KFB apoptosis and anti-proliferation effects.展开更多
The respiratory burst is an important physiological function of the neutrophils in killing the bacteria invading in human body. We used chemiluminescence method to measure the exogenous arachidonic acid-stimulated res...The respiratory burst is an important physiological function of the neutrophils in killing the bacteria invading in human body. We used chemiluminescence method to measure the exogenous arachidonic acid-stimulated respiratory burst, and measured the cytosolic free calcium concentration in neutrophils by the fluorescence method. It was found that, on one hand, the arachidonic acid-stimulated respiratory burst was enhanced by elevating the cytosolic free calcium concentration in neutrophils with a potent endomembrane Ca2+-ATPase inhibitor, Thapsgargin; on the other hand, chelating the intracellular or extracellular calcium by EGTA or BAPTA inhibited the respiratory burst. Results showed that calcium plays an important regulatory role in the signaling pathway involved in the exogenous arachidonic acid-stimulated respiratory burst of neutrophils.展开更多
Elevated plasma levels of free fatty acids(FFAs)may contribute to insulin resistance(IR)that is characteristic of type 2 diabetes mellitus.In this study,we investigated the effects of two fatty acids,palmitate(PA)and ...Elevated plasma levels of free fatty acids(FFAs)may contribute to insulin resistance(IR)that is characteristic of type 2 diabetes mellitus.In this study,we investigated the effects of two fatty acids,palmitate(PA)and arachidonic acid(AA)on glycogenesis under insulin signaling in HepG2cells,a transformed hepatic carcinoma cell line.In the presence of 200μmol of palmitate,insulin(10−7 mol/L)stimulation of glycogenesis was inhibited,as evidenced by increased glucose in the medium and decreased intracellular glycogen.Wortmannin(WM),a specific inhibitor of PI3K,dramatically decreased the amount of intracellular glycogen in cells without PA incubation.However,glycogen in PA treated cells was not significantly changed by WM,indicating that PA may also act on PI3K.Interestingly,AA restored the effects of WM inhibition on glycogenesis in PA cells.Western blot analysis demonstrated that PA in the absence of WM increased phosphorylated glycogen synthase(inactive form of GS)and decreased phosphorylated protein kinase B(active form of PKB),causing a reduction of intracellular glycogen.AA,however,reversed the effects of PA on GS and PKB.Furthermore,inhibition of protein kinase C(PKC)by a specific inhibitor chelerythrine chloride(CC)abolished the inhibitory effect of PA on glycogen synthesis by decreasing phosphorylated GS and increasing phosphorylated PKB.However,the effect of CC in the presence of PA disappeared when AA was also present.Our results suggest that there is a disruption of the insulin signaling pathway between PKB and GS when the cells were exposed to PA,contributing to IR.PA may also interrupt the PKC signaling pathway.In contrast,AA could rescue glycogenesis impaired by PA.展开更多
The analysis of flux distributions in metabolic networks has become an important approach for understand-ing the fermentation characteristics of the process.A model of metabolic flux analysis of arachidonic acid(AA)sy...The analysis of flux distributions in metabolic networks has become an important approach for understand-ing the fermentation characteristics of the process.A model of metabolic flux analysis of arachidonic acid(AA)synthesis in Mortierella alpina ME-1 was established and carbon flux distributions were estimated in different fermentation phases with different concentrations of N-source.During the expo-nential,decelerating and stationary phase,carbon fluxes to AA were 3.28%,8.80%and 6.97%,respectively,with sufficient N-source broth based on the flux of glucose uptake,and those were increased to 3.95%,19.21%and 39.29%,respectively,by regulating the shifts of carbon fluxes via fermentation with limited N-source broth and adding 0.05% NaNO_(3) at 96 h.Eventually AA yield was increased from 1.3 to 3.5 g·L^(−1).These results suggest a way to improve AA fermentation,that is,fermentation with limited N-source broth and adding low concentration N-source during the stationary phase.展开更多
Backgrounds Arachidonic acid (AA) metabolic network is activated in the most inflammatory related diseases, and small-molecular drugs targeting AA network are increasingly available. However, side effects of above men...Backgrounds Arachidonic acid (AA) metabolic network is activated in the most inflammatory related diseases, and small-molecular drugs targeting AA network are increasingly available. However, side effects of above mentioned drugs have always been the biggest obstacle.什)-2-( 1 -hydroxy 1-4-oxocycIohexyl) ethyl caffeate (HOEC), a natural product acted as an inhibitor of 5-Iipoxygenase (5-LOX) and 15-LOX in vitro^ exhibited weaker therapeutic effect in high dose than that in low dose to collagen induced arthritis (CIA) rats. In this study, we tried to elucidate the potential regulatory mechanism by using quantitative pharmacology. Methods: First, we generated an experimental data set by monitoring the dynamics of AA metabolites, concentration in A23187 stimulated and different doses of HOEC co-incubated RAW264.7. Then we constructed a dynamic model of A23187-stimulated AA metabolic model to evaluate how a model-based simulation of AA metabolic data assists to find the most suitable treatment dose by predicting the pharmacodynamics of HOEC? Results: Compared to the experimental data, the model could simulate the inhibitory effect of HOEC on 5-LOX and 15-LOX, and reproduced the increase of the metabolic flux in the cyclooxygenase (COX) pathway. However, a concomitant, early-stage of stimulation-related decrease of prostaglandins (PGs) production in HOEC incubated RAW264.7 cells was not simulated in the model. Conclusion-. Using the model, we predict that higher dose of HOEC disrupts the flux balance in COX and LOX of the AA network, and increased COX flux can interfere the curative effects of LOX inhibitor on resolution of inflammation which is crucial for the efficient and safe drug design.展开更多
基金supported by the National Natural Science Foundation of China (No. 41606180)Young Elite Scientists Sponsorship (No. YESS20150157)
文摘The gonads of sea urchins(Strongylocentrotus intermedius) are characterized by high levels of arachidonic acid(ARA, 20:4 n-6) and eicosapentaenoic acid(EPA, 20:5 n-3). However, to our knowledge, little information is available regarding the physiological response of adult sea urchins to dietary ARA. In the present study, four dietary feeds were formulated with graded ARA(0, 0.5%, 1%, and 2% dry diet). Each diet was randomly allocated to three cages during a 56-day feeding experiment. The results showed that the sea urchin weight gain rate(WGR) and the gonadosomatic index(GI) significantly increased as ARA was equal to or above 1.0% of dry diet(P < 0.05). The activities of superoxide dismutase(SOD), catalase(CAT), and total anti-oxidative capacity(T-AOC) were the highest in the coelomic fluid of sea urchins that were fed diets with 1% ARA. The total essential amino acid(TEAA) and its ratio to total non-essential amino acid(TNEAA) showed a similar tendency to WGR and GI as dietary ARA increased, and the highest TEAA and TEAA/TNEAA were observed in the gonads of sea urchins that were fed diets with 1% ARA. Levels of ARA and ARA/EPA of the gonads increased while n-3/n-6 polyunsaturated fatty acid(PUFA) decreased with the increase of dietary ARA(P < 0.05). EPA in the gonads of experimental animals fed with formulated feeds showed no significant differences(P> 0.05), but was significantly lower than those fed with kelp(P < 0.05). These results suggested that relatively higher levels of ARA(1% dry diet) significantly promoted growth, gonad development, activities of antioxidant enzymes, as well as nutritional values(TEAA, TEAA/TNEAA, and PUFA) of adult S. intermedius.
基金Supported by Young Scientifi c Fund of Heilongjiang Province (QC2010093)Project of Daqing Scientifi c Program (sggh2009-029)
文摘A developed method was used for the enhancement of arachidonic acid production by M. isabellina. An orthogonal, rotatable and central composite design was applied to determine the optimum conditions for protoplast regeneration mutagenesis. The results showed that a commixture enzyme (cellulase and glusulase) at the concentration of 4%, enzymolysis temperature at 30℃ and enzymolysis time on 7.5 h were the optimal conditions, in which the lethality of M. isabellina spores was 78.4%. After mutagenesis and re-screenings, M. isabellina mutant Y-69 was obtained. GC analysis showed that the yield of arachidonic acid by Y-69 (2.92 g. L-1) was 3.56 times higher than that of the wild-type strain (0.82 g.L-1). Pass generation tests showed that the properties of Y-69 by mutation were readily inherited.
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.
文摘Amyloid β(Aβ)1-42 fibrillation is a crucial step in the development of pathological hallmarks, such as neuritic plaques and neurofibrillary tangles, of Alzheimer’s disease (AD). In this study, we evaluated the effects of free docosahexaenoic acid (DHA), an essential brain polyunsaturated fatty acid (PUFA), on the inhibition of Aβ1-42 fibrillation by fluorescence correlation spectroscopy (FCS), a technique capable of detecting molecular movements and interactions in solution. We also examined whether free arachidonic acid (AA), eicosapentaenoic acid (EPA), and metabolites of DHA, including neuroprotectin D1 (NPD1, 10S, 17S-dihydroxy-DHA), resolvin D1 (RvD1, 7S, 8R, 17S-trihydroxy-DHA), and didocosahexaenoyl glycerol (diDHA), affect Aβ1-42 polymerization. The results of the FCS study reveal that DHA and AA significantly reduced the diffusion time of TAMRA (5-carboxytetramethylrhoda-mine)-Aβ1-42 by 28% and 31%, respectively, while EPA, NPD1, RvD1, and diDHA had no effects on diffusion time. These results indicate that DHA and AA inhibited Aβ1-42 polymerization and that their inhibitory effects occurred at the initial stage of Aβ1-42 polymerization. This study will advance the research on PUFAs in preventing AD progression.
基金Supported by the National Natural Science Foundation of China(31171657)Heilongjiang Youth Science Foundation(QC2010093)+1 种基金Heilongjiang Natural Science Foundation(20100481037)Key Projects on Ministry of Education in Heilongjiang(12511Z022)
文摘Arachidonic acid (AA or ARA), an essential to-6 polyunsaturated fatty acid (PUFA), can be produced by Mortierella isabellina. Mutagenesis on Mortierella isabellina As3.3410 was induced to raise ARA production. The mutant strain of YZ-124 had the highest ARA of 4.72 g. L-1, which was 5.5 times higher than that of the original strain 3.3410. mRNA expression level of △ 6- desaturase was determined in five different kinds of ARA-producing Mortierella isabellina after cultured for 7 days, and in the mutant strain YZ-124 over a 3-8 day time-course. In addition, the desaturase activity and ARA content were measured at the selected time points. The lowest expression of △6-desaturase was observed in the original strain and the highest expression in the mutant strain YZ-124, which increased with increasing time in culture. Furthermore, a positive correlation was observed between the expression levels of △6-desaturase and ARA content. Based on this, △6-desaturase played a significant role in ARA synthesis pathway in Mortierella isabellina.
文摘The changes of the levels of LTC4, PGI2 and TXA2 in the liver tissue in SD rats with GaIN/LPS-induced acute liver injury was studied with radioimmunoassay (RIA). As a result,12h after the administration of GaIN/LPS, serum AST (398±37u), ALT (565 ±43u) increased (P<0.001 ) and the concentration of TXA2 (12188±588pg/g· w· wt) in liver tissue increased sigiuficantly(p<0.001), while the content of LTC4 (9713± 3557ng/g·w·wt ) and PGI2 (1748±560 pg/g· w·wt) in liver tissue were not obviously changed(p>0.05) and the inflammatory changes of the pathological findings were observed. The improvement of serum ALT (300±168u)(p< 0.05) and AST(273±424 u) (P<0. 05) and histopathological damage was observed after the administration of diethylcarbamazine (DEC), a LTA4 synthesis inhibitor, the liver TXA2(12740±699) concentration significantly increased (P<0. 001), while the levels of LTC4 (8179±1653) and PGI2 (2320±630) were not obviously changed. Serum ALT (536±74u) and AST (416± 41u)(P> 0. 05) levels and histopathology did not change with administration of indomethacin, a cyclooxygenase inhibitor, but the liver LTC4 (12166±13027) contents increased (P<0.05 ) and TXA2 (1868±791) reduced significantly (P<0. 001). The present study suggests that arachidonic acid metabolism in rats with acute liver injury are significantly abnormal. Leukotrienes and thromboxane are important inflammatory mediators in the liver injury.
基金Supported by the Natural Sceince Foundation ofHubei Province (2003ABA188)
文摘Human umbilical vein endothelial cells (HU VECs) were treated with arachidonic acid (AA). After 24 h exposure to AA, typical morphological changes of apoptosis were observed by Giemsa stain and transmission electron microscopy. The apoptotic ratio in HUVECs treated with 50μmol/L, 100μmol/L and 150μmol/L AA were (20.7±3.6)%, (38.6±4.3)% and (52.5±7.5) % respectively. Contrarily, low concentration of AA (425μmol/L) exerted no influence on cell viability by MTT assay. Intracellular malondialdehyde increased significantly in a dose-dependent manner upon AA treatment and for the reduced glutathione. the opposite tendency was found Western Blots show that apoplosis triggered by AA was associated with the down-regulation of Bcl-2 expression, but not with Bax and p53. Pretreatment with 50μmol/L α-tocopherol reduced AA-induced oxidative stress and apoptosis, also inhibited the dowwregulation of Bcl-2/Bax ratio. These results suggested that high concentration of free AA could induce apoptosis in HUVECs probably via oxidative stress and down-regulation of Bcl-2.
基金Supported by The National Key Technology Research and Development Program of China(2006BAD27B09)Project of the JiangsuKey Laboratory of Marine Biotechnology(2007HS012)
文摘The fatty acids of a strain of Diasporangium sp.had been analyzed by using GC-MS.The fatty acids of twenty mutants were determined.Based on these results,the producing of eicosapentaenoic acid(EPA)supposed via 18∶2,18∶3,20∶3,20∶4 which all belong to ω-6 fatty acids.The ω-3 desaturation was undertaken at arachidonic acid(AA).In addition,mutant strains resulted in enhanced content of AA which could get two times more than initial strain,but no compact on EPA.
文摘Cerebrovascular accident(CVA)or stroke is one of the world's leading causes of death and permanent disability.The high social and medical costs associated with this pathology mean there is an urgent need to find effective therapies.Occlusion of the middle cerebral artery(MCAO),mainly by clots,is the origin of most CVAs in humans.
文摘Pancreatic ductal adenocarcinoma(PDAC)is highly heterogeneous,making its prognosis prediction difficult.The arachidonic acid(AA)cascade is involved in carcinogenesis.Therefore,the metabolic enzymes of the AA cascade consist of lipoxygenases(LOXs),phospholipase A2s(PLA2s),and cyclooxygenases(COXs)along with their metabolic products,including leukotrienes.Nevertheless,the prognostic potential of AA metabolism-associated PDAC has not been explored.Herein,the mRNA expression patterns and the matching clinical information of individuals with PDAC were abstracted from online data resources.We employed the LASSO Cox regression model to develop a multigene clinical signature in the TCGA queue.The GEO queue and the ICGC queue were employed as the validation queue.There was differential expression of a significant number of AA metabolism-associated genes(56.8%)between PDAC and neighboring nonmalignant tissues in the TCGA queue.Univariate Cox regression demonstrated that 13 of the differentially expressed genes(DEGs)were linked to overall survival(OS)(p<0.05).A 6-gene clinical signature was developed for stratifying the PDAC patients into two risk groups,with the high-risk group patients exhibiting remarkably lower OS than the low-risk group patients(p<0.001 in the TCGA data set and the ICGC queue,and p=0.001 in the GEO data set).The multivariate Cox data revealed the risk score as an independent OS predictor(HR>1,p<0.01).The receiver operating characteristic(ROC)curve verified the predictive potential of our signature.The expression and alteration of the six genes in PDAC were also validated using online databases.Functional analyses demonstrated that immune-linked cascades were enriched,and the immune status was remarkably different between the high-and low-risk groups.In summary,an AA metabolism-associated clinical gene signature can be applied for prognostic estimation in PDAC.
文摘Cell signaling is a very complex network of biochemical reactions triggered by a huge number of stimuli coming from the external medium. The function of any single signaling component depends not only on its own structure but also on its connections with other biomolecules. During prokaryotic-eukaryotic transition, the rearrangement of cell organization in terms of diffusional compartmentalization exerts a deep change in cell signaling functional potentiality. In this review I briefly introduce an intriguing ancient relationship between pathways involved in cell responses to chemical agonists (growth factors, nutrients, hormones) as well as to mechanical forces (stretch, osmotic changes). Some biomolecules (ion channels and enzymes) act as "hubs", thanks to their ability to be directly or indirectly chemically/mechanically co-regulated. In particular calcium signaling machinery and arachidonic acid metabolism are very ancient networks, already present before eukaryotic appearance. A number of molecular "hubs", including phospholipase A2 and some calcium channels, appear tightly interconnected in a cross regulation leading to the cellular response to chemical and mechanical stimulations.
文摘Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). This paper mainly introduced the structure, distribution, source, physiologic healthcare function and application of AA.
文摘A microwave irradiated palladium-catalyzed reaction of carboxylic acids and crotyl type bromides creates series of esters in good to high yields. This facile ester synthesis then is applied to make esters from arachidonic acid, salicylic acid, folic acid, and aspirin efficiently.
基金Supported by Joint Guidance Project of Heilongjiang Natural Science Foundation(No.LH2021H099)Start Fund of Postdoctoral Research in Heilongjiang Province(No.LBH-Q19188)+3 种基金Outstanding Youth Development Fund of Heilongjiang University of Chinese Medicine(No.2019JC06)Project of Heilongjiang Administration of Traditional Chinese Medicine(No.ZHY202094)Graduate Innovative Scientific Research Project of Heilongjiang University of Chinese Medicine(No.2020yjscx057)Natural Science Foundation of Heilongjiang Province(Key project,No.ZD2020H006)。
文摘Objective To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino(TSDN)on the arachidonic acid pathway in monosodium urate(MSU)crystal-induced M1-polarized macrophages.Methods M1 polarization of RAW264.7 cells were induced by 1µg/mL lipopolysaccharide(LPS).The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN.MSU(500µg/mL)was used to induce the gouty arthritis model.Afterwards,10µg/L TSDN and 8µmol/L celecoxib,which was used as a positive control,were added to the above LPS and MSU-induced cells for 24 h.The mRNA and protein expressions of cyclooxygenase(COX)2,5-lipoxygenase(5-LOX),microsomal prostaglandin E synthase derived eicosanoids(mPGES)-1,leukotriene B(LTB)4,cytochrome P450(CYP)4A,and prostaglandin E_(2)(PGE_(2))were tested by real-time polymerase chain reaction and Western blotting,respectively.The enzyme-linked immunosorbent assay was used to test the contents of M1 markers,including inducible nitric oxid synthase(NOS)2,CD80,and CD86.Results TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2,5-LOX,CYP4A,LTB4,and PGE_(2)(P<0.01)while increased the mRNA and protein expression of mPGES-1(P<0.05 or P<0.01).TSDN could also significantly decrease the contents of NOS2,CD80,and CD86(P<0.01).Conclusion TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.
基金National Natural Science Foundation of ChinaGrant/Award Number:81774449。
文摘Background:Inflammatory bowel disease(IBD),comprising Crohn's disease(CD)and ulcerative colitis(UC),is a heterogeneous state of chronic intestinal inflammation.Intestinal innate immunity,including innate immune cells,defends against pathogens and excessive entry of gut microbiota,while preserving immune tolerance to resident intestinal microbiota,and may be characterized by its capacity to produce a rapid and nonspecific reaction.The association between microbiota dysbiosis and the pathogenesis of IBD is complex and dynamic.When the intestinal ecosystem is in dysbiosis,the reduced abundance and diversity of intestinal gut microbiota make the host more vulnerable to the attack of exogenous and endogenous pathogenic gut microbiota.The aim of our study was to comprehensively assess the relationship between microbial populations within UC,the signaling pathways of pathogenic gut microbe therein and the inflammatory response,as well as to understand the effects of using PE&AFWE(poppy extract[Papaver nudicaule L.]and Artemisia frigida Willd.extract)on UC modulation.Methods:A UC mouse model was established by inducing SPF-grade C57BL/6 mice using dextrose sodium sulfate(DSS).Based on metagenomic sequencing to characterize the gut microbiome,the relationship between gut microbiota dysbiosis and gut microbiota was further studied using random forest and Bayesian network analysis methods,as well as histopathological analysis.Results:(1)We found that the 5 gut microbiota with the highest relative abundance of inflammatory bowel disease UC model gut microbiota were consistent with the top 5 ranked natural bacteria.There were three types of abundance changes in the model groups:increases(Chlamydiae/Proteobacteria and Deferribacteres),decreases(Firmicutes),and no significant changes(Bacteroidetes).The UC model group was significantly different from the control group,with 1308 differentially expressed species with abundance changes greater than or equal to 2-fold.(2)The proportion of the fecal flora in the UC group decreased by 37.5%in the Firmicutes and increased by 14.29%in the proportion of Proteobacteria compared to the control group before treatment.(3)The significantly enriched and increased signaling pathways screened were the'arachidonic acid metabolic pathway'and the'phagosomal pathway',which both showed a decreasing trend after drug administration.(4)Based on the causal relationship between different OTUs and the UC model/PE&AFWE administration,screening for directly relevant OTU networks,the UC group was found to directly affect OTU69,followed by a cascade of effects on OTU12,OTU121,OTU93,and OTU7,which may be the pathway of action that initiated the pathological changes in normal mice.(5)We identified a causal relationship between common differentially expressed OTUs and PE&AFWE and UC in the pre-and post-PE&AFWE-treated groups.Thereby,we learned that PE&AFWE can directly affect OTU90,after which it inhibits UC,inhibiting the activity of arachidonic acid metabolic pathway by affecting OTU118,which in turn inhibits the colonization of gut microbiota by OTU93 and OTU7.(6)Histopathological observation and scoring(HS)of the colon showed that there was a significant difference between the model group and the control group(p<0.001),and that there was a significant recovery in both the sulfasalazine(SASP)and the PE&AFWE groups after the administration of the drug(p<0.0001).Conclusion:We demonstrated causal effects and inflammatory metabolic pathways in gut microbiota dysbiosis and IBD,with five opportunistic pathogens directly contributing to IBD.PE&AFWE reduced the abundance of proteobacteria in the gut microbiota,and histopathology showed significant improvement.
基金supported by grant from the National Natural Science Foundation of China(No.81772085).
文摘Background:The clinical features of keloids consist of aberrant proliferation,secretion,differentiation and apoptosis of keloid dermis-derived fibroblasts(KFBs).Notably,the apoptosis rate of KFBs is lower than the proliferation rate.Though the anti-fibrotic effect of adipose-derived stem cells(ADSCs)on keloids has become a hot topic of research,the exact anti-fibrotic mechanism of the paracrine effect remains unclear.This study aimed to find out how the conditioned medium of ADSCs(ADSC-CM)exerts an anti-fibrotic effect in KFBs.Methods:KFBs and ADSCs were extracted and cultured.Then,ADSC-CM was prepared.Whether ADSC-CM could inhibit KFB growth and induce apoptosis was verified by the use of a cell counting kit-8,an 5-Ethynyl-2-deoxyuridine(Edu)kit and flow cytometry.The expressions of cyclooxygenase-1(COX-1),COX-2,caspase 3 and B-cell lymphoma-2(Bcl-2)in ADSC-CM-cultured KFBs were tested by real-time PCR and western blotting.To clarify the role of COX-2 in ADSC-CM-induced KFB apoptosis,a specific COX-2 inhibitor,celecoxib,was applied to KFBs cultured in ADSC-CM.Moreover,we tested the production of arachidonic acid(AA)and prostaglandin E2(PGE2)by ELISA.Then,we established a keloid transplantation model in a nude mouse to validate the therapeutic effect in vivo.Results:The proliferation ability of KFBs cultured in ADSC-CM was found to be weakened and apoptosis was significantly increased.Caspase 3 expression was significantly upregulated and Bcl-2 was downregulated in ADSC-CM-cultured KFBs.Furthermore,ADSC-CM strikingly elevated COX-2 mRNA and protein expressions,but COX-1 expression was unaltered.COX-2 inhibitors reduced ADSC-CM-induced apoptosis.Additionally,COX-2 inhibition blocked the elevation of caspase 3 and reversed the decrease in Bcl-2 expression.ADSC-CM increased PGE2 levels by 1.5-fold and this effect was restrained by COX-2 inhibition.In the nude mouse model,expressions of AA,COX-2 and PGE2 were higher in the translated keloid tissues after ADSC-CM injection than in the controls.Conclusions:We showed activation of the COX-2/PGE2 cascade in KFBs in response to ADSC-CM.By employing a specific COX-2 inhibitor,COX-2/PGE2 cascade activation played a crucial role in mediating the ADSC-CM-induced KFB apoptosis and anti-proliferation effects.
基金the National Natural Science Foundation of China (Grant No. 39670205).
文摘The respiratory burst is an important physiological function of the neutrophils in killing the bacteria invading in human body. We used chemiluminescence method to measure the exogenous arachidonic acid-stimulated respiratory burst, and measured the cytosolic free calcium concentration in neutrophils by the fluorescence method. It was found that, on one hand, the arachidonic acid-stimulated respiratory burst was enhanced by elevating the cytosolic free calcium concentration in neutrophils with a potent endomembrane Ca2+-ATPase inhibitor, Thapsgargin; on the other hand, chelating the intracellular or extracellular calcium by EGTA or BAPTA inhibited the respiratory burst. Results showed that calcium plays an important regulatory role in the signaling pathway involved in the exogenous arachidonic acid-stimulated respiratory burst of neutrophils.
基金This study was supported by grants from the Natural Science Foundation of the Hubei Province(2003ABA137)Research Foundation of the Health Department of Hubei Province(NX200403).
文摘Elevated plasma levels of free fatty acids(FFAs)may contribute to insulin resistance(IR)that is characteristic of type 2 diabetes mellitus.In this study,we investigated the effects of two fatty acids,palmitate(PA)and arachidonic acid(AA)on glycogenesis under insulin signaling in HepG2cells,a transformed hepatic carcinoma cell line.In the presence of 200μmol of palmitate,insulin(10−7 mol/L)stimulation of glycogenesis was inhibited,as evidenced by increased glucose in the medium and decreased intracellular glycogen.Wortmannin(WM),a specific inhibitor of PI3K,dramatically decreased the amount of intracellular glycogen in cells without PA incubation.However,glycogen in PA treated cells was not significantly changed by WM,indicating that PA may also act on PI3K.Interestingly,AA restored the effects of WM inhibition on glycogenesis in PA cells.Western blot analysis demonstrated that PA in the absence of WM increased phosphorylated glycogen synthase(inactive form of GS)and decreased phosphorylated protein kinase B(active form of PKB),causing a reduction of intracellular glycogen.AA,however,reversed the effects of PA on GS and PKB.Furthermore,inhibition of protein kinase C(PKC)by a specific inhibitor chelerythrine chloride(CC)abolished the inhibitory effect of PA on glycogen synthesis by decreasing phosphorylated GS and increasing phosphorylated PKB.However,the effect of CC in the presence of PA disappeared when AA was also present.Our results suggest that there is a disruption of the insulin signaling pathway between PKB and GS when the cells were exposed to PA,contributing to IR.PA may also interrupt the PKC signaling pathway.In contrast,AA could rescue glycogenesis impaired by PA.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20576054)Natural Science Foundation of Jiangsu(Grant No.BK2005114)Jiangsu Planned Projects for Postdoctoral Research Funds.
文摘The analysis of flux distributions in metabolic networks has become an important approach for understand-ing the fermentation characteristics of the process.A model of metabolic flux analysis of arachidonic acid(AA)synthesis in Mortierella alpina ME-1 was established and carbon flux distributions were estimated in different fermentation phases with different concentrations of N-source.During the expo-nential,decelerating and stationary phase,carbon fluxes to AA were 3.28%,8.80%and 6.97%,respectively,with sufficient N-source broth based on the flux of glucose uptake,and those were increased to 3.95%,19.21%and 39.29%,respectively,by regulating the shifts of carbon fluxes via fermentation with limited N-source broth and adding 0.05% NaNO_(3) at 96 h.Eventually AA yield was increased from 1.3 to 3.5 g·L^(−1).These results suggest a way to improve AA fermentation,that is,fermentation with limited N-source broth and adding low concentration N-source during the stationary phase.
基金the National Key Research and Development Program (No. 2016YFA0502304)Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase, No.U150l501)the National Natural Science Foundation of China (No. 21173076).
文摘Backgrounds Arachidonic acid (AA) metabolic network is activated in the most inflammatory related diseases, and small-molecular drugs targeting AA network are increasingly available. However, side effects of above mentioned drugs have always been the biggest obstacle.什)-2-( 1 -hydroxy 1-4-oxocycIohexyl) ethyl caffeate (HOEC), a natural product acted as an inhibitor of 5-Iipoxygenase (5-LOX) and 15-LOX in vitro^ exhibited weaker therapeutic effect in high dose than that in low dose to collagen induced arthritis (CIA) rats. In this study, we tried to elucidate the potential regulatory mechanism by using quantitative pharmacology. Methods: First, we generated an experimental data set by monitoring the dynamics of AA metabolites, concentration in A23187 stimulated and different doses of HOEC co-incubated RAW264.7. Then we constructed a dynamic model of A23187-stimulated AA metabolic model to evaluate how a model-based simulation of AA metabolic data assists to find the most suitable treatment dose by predicting the pharmacodynamics of HOEC? Results: Compared to the experimental data, the model could simulate the inhibitory effect of HOEC on 5-LOX and 15-LOX, and reproduced the increase of the metabolic flux in the cyclooxygenase (COX) pathway. However, a concomitant, early-stage of stimulation-related decrease of prostaglandins (PGs) production in HOEC incubated RAW264.7 cells was not simulated in the model. Conclusion-. Using the model, we predict that higher dose of HOEC disrupts the flux balance in COX and LOX of the AA network, and increased COX flux can interfere the curative effects of LOX inhibitor on resolution of inflammation which is crucial for the efficient and safe drug design.