Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

A Diet with 3% of Energy from a Mixture of Omega-3 Fatty Acids Significantly Increases in Vivo Lipid Peroxidation in Postmenopausal Women

Dietary omega-3 (n - 3) polyunsaturated fatty acids (PUFA) are recommended by public health organizations to reduce the risk of cardiovascular disease, and several epidemiological studies have suggested there is an inverse association between n - 3 intake and human cancers. However, n - 3 are susceptible to an increase in lipid peroxidation in the human body. As part of a crossover dietary intervention study of a diet (20% of energy from fat) with or without an additional 3% of energy from a mixture of n - 3 (with 5.36 g α-linolenic acid and 1.45 g eicosapentaenoic acid and docosahexaenoic acid per 2000 kcal per day), we measured total in vivo lipid peroxidation in healthy postmenopausal women (n = 15). Our results indicated that the diet with 3% of energy from n - 3 significantly increased the urinary concentrations of total polar lipophilic aldehydes and related compounds produced via lipid peroxidation (p α, β-unsaturated hydroxy aldehydes 4-hydroxy-2-trans - hexenal (p trans -decenal (p < 0.05) compared to the diet with less than 1% of energy from n - 3. This is also the first study to document the presence of 4-hydroxy-2-trans -decenal in the urine of individuals consuming n - 3. These results demonstrate that an increase in 3% of energy from dietary n – 3 increases in vivo lipid peroxidation.

Transgenic Pigs Carrying a Synthesized Fatty Acid Desaturase Gene Yield High Level of ω-3 PUFAs

Polyunsaturated fatty acids （PUFAs） are essential for normal growth in mammals, especially the ω-3 PUFAs, which play important roles in preventing several life-threatening diseases, such as coronary heart disease and diabetes. In this study, we aimed to investigate whether the sFat-1 gene from Caenorhabditis briggsae could be functionally expressed in transgenic pigs, and whether the transgenic could synthesize high quality ω-3 PUFAs endogenously. In this study, a gene construct consisting of CMV promoter and 1.9 kb cDNA of ω-3 fatty acid desaturase gene （sFat-1） from C. briggsae was injected into the male pronucleus of pig embryos by microinjection. The piglets were screened for the transgene by PCR, Southern blot and reverse transcription-PCR analysis. Pigs that give positive results were mated with wild-type pigs to produce the next generation and the transmission of transgene was examined by PCR analysis. Fatty acids compositions of various tissues in the transgenic pigs were then analyzed by gas chromatograph. A total of 878 embryos were transferred into 42 recipients, among which 29 successfully got pregnant and gave birth to a total of 162 piglets, and 8 of them were identified to be transgenic. Fatty acid compositions in the transgenic pigs were altered, and the levels of ω-6：ω-3 ratios were decreased from 14.53 in the control to 2.62 in Fat-1 transgenic pigs. A number of primary sFat-1-transgenic pigs were bred in this study, which lays the foundation for cultivation of new varieties of transgenic pigs.

Usefulness of ω-3 fatty acid supplementation in addition to mesalazine in maintaining remission in pediatric Crohn's disease: A double-blind, randomized, placebo-controlled study

AIM： To assess the value of long-chain w-3 fatty acids （FAs） supplementation in addition to amino-salicylic-acid （5-ASA） in pediatric patients with Crohn＇s disease （CD）. METHODS： Thirty-eight patients （20 males and 18 females, mean age 10.13 years, range 5-16 years） with CD in remission were randomized into two groups and treated for 12 too. Group Ⅰ （18 patients） received 5-ASA （50 mg/kg/d）＋w-3 FAs as triglycerides in gastroresistant capsules, 3 g/d （eicosapentanoic acid, EPA, 400 mg/g, docosahexaenoic acid, DHA, 200 mg/g）. Group Ⅱ （20 patients） received 5-ASA （50 mg/kg/d）＋olive oil placebo capsules. Patients were evaluated for fatty acid incorporation in red blood cell membranes by gas chromatography at baseline 6 and 12 mo after the treatment. RESULTS： The number of patients who relapsed at 1 year was significantly lower in group I than in group Ⅱ （P〈0.001）. Patients in group I had a significant increase in the incorporation of EPA and DHA （P〈0.001） and a decrease in the presence of arachidonic acids. CONCLUSION： Enteric-coated w-3 FAs in addition to treatment with 5-ASA are effective in maintaining remission of pediatric CD.

Effect of ω-3 Polyunsaturated Fatty Acid on Toll-like Receptors in Patients with Severe Multiple Trauma

This study examined the effects of ω-3 polyunsaturated fatty acid（ω-3PUFA） on the expression of toll-like receptor 2（TLR2）,toll-like receptor 4（TLR4） and some related inflammatory factors in peripheral blood mononuclear cells（PBMCs） of patients with early-stage severe multiple trauma.Thirty-two patients who were admitted to the Department of Traumatic Surgery,Tongji Hospital（Wuhan,China） between May 2010 and November 2010,and diagnosed as having severe multiple trauma with a injury severity score（ISS） no less than 16,were enrolled in the study and divided into two groups at random（n=16 in each）：ω-3PUFA group and control group in which routine parenteral nutrition supplemented with ω-3PUFA or not was administered to the patients in two groups for consecutive 7 days.Peripheral blood from these patients was collected within 2 h of admission（day 0）,and 1,3,5 and 7 days after the nutritional support.PBMCs were isolated and used for detection of the mRNA and protein expression of TLR2 and TLR4 by using real-time PCR and flow cytometry respectively,the levels of NF-κB by quantum dots-based immunofluorescence assay,the levels of TNF-α,IL-2,IL-6 and COX-2 by ELISA,respectively.The results showed that the mRNA and protein expression of TLR2 and TLR4 in PBMCs was significantly lower in ω-3PUFA group than in control group 5 and 7 days after nutrition support（both P0.05）.The levels of TNF-α,IL-2,IL-6 and COX-2 were found to be substantially decreased in PBMCs in ω-3PUFA group as compared with control group at 5th and 7th day（P0.05 for all）.It was concluded that ω-3PUFA can remarkably decrease the expression of TLR2,TLR4 and some related inflammatory factors in NF-κB signaling pathway in PBMCs of patients with severe multiple trauma,which suggests that ω-3PUFA may suppress the excessive inflammatory response meditated by the TLRs/NF-κB signaling pathway.

Free fatty acids, glucose, and insulin in type 2 diabetes mellitus

Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based on the assumption that the glucose-insulin axis is central for the metabolic activities,which led to type 2 diabetes.However,significant downregulation of both the NKX2-1 gene and the TPD52L3 gene force an increase in the release of free fatty acids(FFAs)into the blood circulation,which leads to a marked reduction in membrane flexibility.These data favor a FFA-glucose-insulin axis.The authors are invited to extend their study with the introduction of the saturation index(number of carbon-carbon double bonds per 100 fatty-acyl chains),as observed in erythrocytes.

Cytochrome P450 monooxygenase-mediated eicosanoid pathway:A potential mechanistic linkage between dietary fatty acid consumption and colon cancer risk

Human consumption of linoleic acid(LA,18:2ω-6,abundant in vegetable oils)is very high.Animal experiments showed that excessive LA intake increased azoxymethane-induced colon tumorigenesis,however,the impact of excessive LA on colon cancer in human is not conclusive,making it difficult to make dietary recommendations for optimal intake of LA.Understanding the molecular mechanisms of LA on colon tumorigenesis could help to clarify its health effect,and facilitate development of mechanismbased strategies for preventing colon cancer.Recent studies show that the previously unappreciated cytochrome P450 monooxygenase-mediated eicosanoid pathway is upregulated in colon cancer and plays critical roles in its pathogenesis,and could contribute to the effects of dietary LA,as well asω-3 fatty acids,on colon tumorigenesis.In this review,we will discuss recent studies about the roles of cytochrome P450 monooxygenases in fatty acid metabolism and its roles in colonic inflammation and colon cancer,and how this information could help us to clarify the health impacts of dietary fatty acids.

The Effects of Dietary Fatty Acid Pattern on Layer's Performance and Egg Quality

The feeding trial was conducted to determine the effects of flaxseed on layer＇s performance and egg quality, and the effects of the dietary ratio of ω-6 fatty acid to ω-3 fatty acid on fatty acid deposition in yolk using flaxseed as resource of ω-3 fatty acid and sunflower seed as resource of ω-6 fatty acid. 192 20-wk-old Newroman commercial hens were randomly divided into 4 treatment groups with 6 replicates containing 8 birds. The rations corresponding with the four treatments were formulated with 4% flaxseed ＋ 9% sunflower seed, 8% flaxseed ＋ 18% sunflower seed, 15% flaxseed, and soybean meal, respectively. Sunflower seed was unshelled and flaxseed was whole. Ratios of ω-6 fatty acid to ω-3 fatty acid in 4 dietary treatments were 5.67, 5.21, 1.07, and 11.83, respectively. It can be concluded that long-term feeding 15% flaxseed had no significant （P〉 0.05） influence on egg production, egg weight, eggshell quality, yolk weight, and percentage of yolk weight. Dietary ratio of ω-6 fatty acid to ω-3 fatty acid had impact on the 0-3 fatty acid levels in yolk, nevertheless yolk fatty acid profiles were different from those of dietary fatty acid compositions.

Is there a role of lipid-lowering therapies in the management of fatty liver disease?

Atherogenic dyslipidemia is characterized by increased triglyceride-rich lipoproteins and low high-density lipoprotein cholesterol concentrations.It is highly prevalent in non-alcoholic fatty liver disease(NAFLD)and contributes to the increased cardiovascular risk associated with this condition.Alongside insulin resistance it plays an important pathogenetic role in NAFLD/non-alcoholic steatohepatitis(NASH)development and progression.It has been shown that cholesterol-lowering reduces cardiovascular risk more in NAFLD vs non-NAFLD high-risk individuals.This evidence highlights the importance of effective lipid modulation in NAFLD.In this narrative review the effects of the most commonly used lipid-lowering therapies on liver outcomes alongside their therapeutic implications in NAFLD/NASH are critically discussed.Preclinical and clinical evidence suggests that statins reduce hepatic steatosis,inflammation and fibrosis in patients with NAFLD/NASH.Most data are derived from observational and small prospective clinical studies using changes in liver enzyme activities,steatosis/fibrosis scores,and imaging evidence of steatosis as surrogates.Also,relevant histologic benefits were noted in small biopsy studies.Atorvastatin and rosuvastatin showed greater benefits,whereas data for other statins are scarce and sometimes conflicting.Similar studies to those of statins showed efficacy of ezetimibe against hepatic steatosis.However,no significant anti-inflammatory and anti-fibrotic actions of ezetimibe have been shown.Preclinical studies showed that fibrates through peroxisome proliferator-activated receptor(PPAR)αactivation may have a role in NAFLD prevention and management.Nevertheless,no relevant benefits have been noted in human studies.Species-related differences in PPARαexpression and its activation responsiveness may help explain this discrepancy.Omega-3 fatty acids reduced hepatic steatosis in numerous heterogeneous studies,but their benefits on hepatic inflammation and fibrosis have not been established.Promising preliminary data for the highly purified eicosapentaenoic acid require further confirmation.Observational studies suggest that proprotein convertase subtilisin/kexin9 inhibitors may also have a role in the management of NAFLD,though this needs to be established by future prospective studies.

ω-3PUFAs Prevent MK-801-induced Cognitive Impairment in Schizophrenic Rats via the CREB/BDNF/TrkB Pathway

This study was to determine the protective effect of ω-3 polyunsaturated fatty acids（ω-3PUFAs） on MK-801-induced cognitive impairment in schizophrenia（SZ） rats and the underlying mechanism. A rat model of schizophrenia was induced by MK-801. The cognitive function of rats was assessed using a Morris water maze. The number of hippocampal neurons was measured by Nissl staining. The expression of CREB, p-CREB, BDNF, TrkB, p-TrkB, AKT, p-AKT, ERK, and p-ERK in the hippocampus of rats was detected by Western blotting. The results showed that ω-3PUFAs attenuated MK-801-induced cognitive impairment and hippocampal neurons loss, reversed the injury of the CREB/BDNF/TrkB pathway induced by MK-801, and antagonized MK-801-induced down-regulation of p-AKT and p-ERK in the hippocampus of rats. In conclusion, ω-3PUFAs enhances the CREB/BDNF/TrkB pathway by activating ERK and AKT, thereby increasing the synaptic plasticity and decreasing neuron loss, and antagonizing MK-801-induced cognitive impairment in schizophrenic rats.

Antisense-Mediated Depletion of Tomato Chloroplast Omega-3 Fatty Acid Desaturase Enhances Thermal Tolerance

A chloroplast-localized tomato （Lycopersicon esculentum Mill.） ω-3 fatty acid desaturase gene （LeFADT） was isolated and characterized with regard to its sequence, response to various temperatures, and function in antisense transgenic tomato plants. The deduced amino acid sequence had four histidine-rich regions, of which three regions were highly conserved throughout the whole ω-3 fatty acid desaturasegene family. Southern blotting analysis showed that LeFAD7was encoded by a single copy gene and had two homologous genes in the tomato genome. Northern blot showed that LeFAD7 was expressed in all organs and was especially abundant in leaf tissue. Meanwhile, expression of LeFAD7 was induced by chilling stress （4 ℃）, but was inhibited by high temperature （45 ℃）, in leaves. Transgenic tomato plants were produced by integration of the antisense LeFAD7DNA under the control of a CaMV35S promoter into the genome. Antisense transgenic plants with lower 18 ： 3 content could maintain a higher maximal photochemical efficiency （Fv/Fm） and O2 evolution rate than wild-type plants. These results suggested that silence of the LeFAD7 gene alleviated high-temperature stress. There was also a correlation between the low content of 18 ： 3 resulting from silence of the LeFAD7 gene and tolerance to high-temperature stress.

Lipid and fatty acid fractions in Lingula anatina(Brachiopoda):an intertidal benthic fauna in the West Bengal-Orissa coast,India

Objective:To record the fractional components of lipid and polyunsaturated fatty acids of Lingula anatina(L.anatina),a Precambrian intertidal benthic brachiopod,giving emphasis on-ω series group especially eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)alongside assessing their biotransformation within the population and mangrove-estuarine associated community.Methods:Different biological samples after being collected from three contrasting study sites viz.SI,SII and SIII at Talsari(Longitude 87°5′E to 88°5′E and Latitude 20°30′N to 22°2′N)were stored at-20°C until analyzed.Total lipids were extracted from each sample following Bligh and Dryer method.Identification and conformation of fatty acids were done by following Ackman method.Results:On analyzing different collected samples,muscles of L.anatina exhibited the highest amount of total lipids(2.95%)of which 54.03%belongs to phospholipid groups.Different body parts of studied species contained appreciable and greater amount of EPA and DHA than α-linolenic acid.Conclusions:Different collected samples exhibited variabilities in respect of total lipids and its fractional fatty acid components.The muscles of L.anatina showed maximum storage of lipids and fatty acids.Differential occurrences of EPA and DHA in different body parts of L.anatina are supposed to be due to the biotransformation process converting theα-linolenic acid from its primary food sources.

麻疯树JcFAD7基因启动子克隆及植物表达载体构建

利用TAIL-PCR技术成功克隆了麻疯树JcFAD7基因起始密码子的上游1926bp序列。利用生物信息学手段对其序列特征和潜在的调控元件进行分析表明,该序列含有4个TATA-box和6个CAAT-box,还包含光响应元件、MYB结合位点、不同的激素反应元件以及各种胁迫响应元件,说明JcFAD7的表达可能受多种因素的调控。将启动子连接到pBI101.1载体,成功构建了驱动报告基因GUS的植物表达载体。为阐明麻疯树不饱和脂肪酸的合成代谢过程和植物生长发育的调控机理奠定了基础。

Effect of fish oil enriched enteral diet on inflammatory bowel disease tissues in organ culture: Differential effects on ulcerative colitis and Crohn's disease

AIM： To investigate the influence of fish oil enriched enteral diet on intestinal tissues taken from Crohn＇s disease （CD）, ulcerative colitis （UC） and non-inflamed non-IBD control patients in vitro. METHODS： Colonoscopic biopsies from patients with active CD （n = 4）, active UC （n = 7）, and non-inflamed non-IBD control patients （n = 4） were incubated （three dilutions of 1：20, 1：10, and 1：5） with Waymouth＇s culture medium and enteral elemental diet （EO28, SHS, Liverpool, UK） modified in the fatty acid composition with fish oil （EF） in an organ culture system for 24 h. In each experimental set-up, incubation with Waymouth＇s medium alone as control was included. Tissue viability was assessed by adding bromodeoxyuridine （BrdU） to the culture fluid and immunohistochemically staining for BrdU uptake. Cytokine ratio of IL-1ra/IL-1β （low ratio indicative of inflammation） and production of those cytokines as a percentage of medium control were assayed in the culture supernatant. RESULTS： Incubation of CD-affected tissue with EF （1：20, 1：10, and 1：5） modestly and non-significantly increased IL-1ra/IL-1β ratio as compared with medium control （CD 39.1±16.1; 26.5±7.8, 47.1±16.8 vs control 13.0±2.2）, but incubation of UC-affected tissues increased IL-1ra/IL-1β ratio significantly in all three dilutions （UC 69.1±32.2, P〈0.05; 76.1±36.4, P = 0.05; 84.5±37.3, P〈0.02; vs control 10.2±3.7）. Incubation of non-inflamed non-IBD control tissue did not increase the IL-1ra/IL-1β ratio in any dilution compared to medium control （69.3±47.0, 54.1±30.6, 79.4±34.0 vs control 76.1±37.3）. Average percentage production of IL-1β indexed against medium control was significantly less in UC after EF incubation as compared with CD （UC 24.0±4.8 vs CD 51.8±8.1; P〈0.05）. Average percentage production of IL-tra was markedly higher in UC （135.9±3.4） than that in control patients （36.5±4.3） （p〈0.0001）. CONCLUSION： IBD tissues, after incubation with elemental diet modified in its fatty acid composition with fish oil, show an increase in IL-1ra/IL-1β cytokine ratio. This effect of ω-3 fatty acid modulation is significantly more marked in UC compared with CD and is accompanied by both a reduction of IL-1β and increase of IL-1ra. The positive direct anti-inflammatory effect of elemental diet with fish oil in tissue affected with UC suggests dietary treatment of UC may be possible.

Modulatory Effects of EPA and DHA on Proliferation and Apoptosis of Pancreatic Cancer Cells

In order to investigate the effects of eicosapentaenoic acid （EPA） and docosahexaenoic acid （DHA） on the proliferation, apoptosis of pancreatic cancer cell line SW1990 cells and the expression of cyclin E mRNA, the SW1990 cells were treated with different concentrations of EPA or DHA （20, 40, 60 μg/mL） for 0, 12, 24, 36 and 48 h respectively. By using MTF method, the inhibitory effects of EPA or DHA on the cell growth were assayed. Real time PCR was used to detect the expression changes of cyclin E mRNA after the SW1990 cells were treated with 40μg/mL EPA or DHA for different time. Flow cytometry was used to test the changes of apoptostic rate in the SW1990 cells treated with different concentrations of EPA or DHA for 24 h. The results showed that EPA and DHA could inhibit the growth of SW1990 cells in a time- and concentration-dependent manner （P〈0.01）. EPA or DHA could also significantly inhibit the expression of cyclin E mRNA in a time-dependent manner （P〈0.05）. EPA or DHA could induce the apoptosis of SW1990 cells in a concentration-dependent manner （P〈0.01）. It was concluded that ω-3 fatty acid could inhibit the proliferation of pancreatic cancer cell line SW1990 cells and promote their apoptosis. The down-regulation of the cyclin E expression by ω-3 fatty acid might be one of the mechanisms for its anti-tumor effect on pancreatic cancer.

Synthesis of unsaturated phosphatidyl inositol-3,4,5-trisphosphate

Phosphatidylinositol polyphosphate (PIPx) are related with tyrosine kinase activation and cell proliferation and carcinogenesis. PIPx is an important target compound for synthetic organic chemist. PIPx having saturated fatty acid components have been reported. Recently we have succeeded in the synthesis of phosphatydylinositol-3,4,5-trisphosphate with unsaturated fatty acid component by the reaction of diethyl chlorophosphite with 1,2-di-O-cyclohexylidene-3,4-0-(tetraisopropyldisiloxane 1,3-diyl)-6-O-(4-oxopentanoyl)-myo-inositol.