Landscape of Sequence Variations in Homologous Copies of FAD2 and FAD3 in Rapeseed(Brassica napus L.)Germplasm with High/Low Linolenic Acid Trait

Genetic manipulation(either restraint or enhancement)of the biosynthesis pathway ofα-linolenic acid(ALA)in seed oil is an important goal in Brassica napus breeding.B.napus is a tetraploid plant whose genome often har-bors four and six homologous copies,respectively,of the two fatty acid desaturases FAD2 and FAD3,which con-trol the last two steps of ALA biosynthesis during seed oil accumulation.In this study,we compared their promoters,coding sequences,and expression levels in three high-ALA inbred lines 2006L,R8Q10,and YH25005,a low-ALA line A28,a low-ALA/high-oleic-acid accession SW,and the wildtype ZS11.The expression levels of most FAD2 and FAD3 homologs in the three high-ALA accessions were higher than those in ZS11 and much higher than those in A28 and SW.The three high-ALA accessions shared similar sequences with the pro-moters and CDSs of BnFAD3.C4 and BnFAD3.A3.In A28 and SW,substitution of three amino acid residues in BnFAD2.A5 and BnFAD2.C5,an absence of BnFAD2.C1 locus,and a 549 bp long deletion on the BnFAD3.A3 promoter were detected.The profile of BnFAD2 mutation in the two low-ALA accessions A28 and SW is different from that reported in previous studies.The mutations in BnFAD3 in the high-ALA accessions are reported for thefirst time.In identifying the sites of these mutations,we provide detailed information to aid the design of mole-cular markers for accelerated breeding schemes.

USP19 Stabilizes TAK1 to Regulate High Glucose/Free Fatty Acid-induced Dysfunction in HK-2 Cells

Objective Obesity-induced kidney injury contributes to the development of diabetic nephropathy(DN).Here,we identified the functions of ubiquitin-specific peptidase 19(USP19)in HK-2 cells exposed to a combination of high glucose(HG)and free fatty acid(FFA)and determined its association with TGF-beta-activated kinase 1(TAK1).Methods HK-2 cells were exposed to a combination of HG and FFA.USP19 mRNA expression was detected by quantitative RT-PCR(qRT-PCR),and protein analysis was performed by immunoblotting(IB).Cell growth was assessed by Cell Counting Kit-8(CCK-8)viability and 5-ethynyl-2′-deoxyuridine(EdU)proliferation assays.Cell cycle distribution and apoptosis were detected by flow cytometry.The USP19/TAK1 interaction and ubiquitinated TAK1 levels were assayed by coimmunoprecipitation(Co-IP)assays and IB.Results In HG+FFA-challenged HK-2 cells,USP19 was highly expressed.USP19 knockdown attenuated HG+FFA-triggered growth inhibition and apoptosis promotion in HK-2 cells.Moreover,USP19 knockdown alleviated HG+FFA-mediated PTEN-induced putative kinase 1(PINK1)/Parkin pathway inactivation and increased mitochondrial reactive oxygen species(ROS)generation in HK-2 cells.Mechanistically,USP19 stabilized the TAK1 protein through deubiquitination.Importantly,increased TAK1 expression reversed the USP19 knockdown-mediated phenotypic changes and PINK1/Parkin pathway activation in HG+FFA-challenged HK-2 cells.Conclusion The findings revealed that USP19 plays a crucial role in promoting HK-2 cell dysfunction induced by combined stimulation with HG and FFAs by stabilizing TAK1,providing a potential therapeutic strategy for combating DN.

Serum bile acid and unsaturated fatty acid profiles of non-alcoholic fatty liver disease in type 2 diabetic patients

BACKGROUND The understanding of bile acid(BA)and unsaturated fatty acid(UFA)profiles,as well as their dysregulation,remains elusive in individuals with type 2 diabetes mellitus(T2DM)coexisting with non-alcoholic fatty liver disease(NAFLD).Investigating these metabolites could offer valuable insights into the pathophy-siology of NAFLD in T2DM.AIM To identify potential metabolite biomarkers capable of distinguishing between NAFLD and T2DM.METHODS A training model was developed involving 399 participants,comprising 113 healthy controls(HCs),134 individuals with T2DM without NAFLD,and 152 individuals with T2DM and NAFLD.External validation encompassed 172 participants.NAFLD patients were divided based on liver fibrosis scores.The analytical approach employed univariate testing,orthogonal partial least squares-discriminant analysis,logistic regression,receiver operating characteristic curve analysis,and decision curve analysis to pinpoint and assess the diagnostic value of serum biomarkers.RESULTS Compared to HCs,both T2DM and NAFLD groups exhibited diminished levels of specific BAs.In UFAs,particular acids exhibited a positive correlation with NAFLD risk in T2DM,while theω-6:ω-3 UFA ratio demonstrated a negative correlation.Levels ofα-linolenic acid andγ-linolenic acid were linked to significant liver fibrosis in NAFLD.The validation cohort substantiated the predictive efficacy of these biomarkers for assessing NAFLD risk in T2DM patients.CONCLUSION This study underscores the connection between altered BA and UFA profiles and the presence of NAFLD in individuals with T2DM,proposing their potential as biomarkers in the pathogenesis of NAFLD.

Association of Bovine Fatty Acid Desaturase 2 Gene Single-Nucleotide Polymorphisms with Intramuscular Fatty Acid Composition in Japanese Black Steers

Beef from Japanese Black cattle (JBK), is popular in Japan and valued for its highly marbled fat content. In JBK, genes affecting oleic acid content in meat have been studied mainly to lower the fat melting point and improve tenderness;however, there has been no direct correlation demonstrated between beef taste and oleic acid. To investigate genes affecting other fatty acids other than oleic acid, polymorphisms of the fatty acid desaturase 2 (FADS2) gene were genotyped and associations with fatty acid profile in JBK beef were investigated. Amplifications of 5’-flanking regions, 12 exons, and 3’-untranslated regions of the FADS2 gene in three Japanese and five Western cattle breeds via PCR, were amplified, sequenced and SNPs were identified using specific TaqMan genotyping assay. Fatty acid composition of intramuscular adipose tissue of the Trapezius muscle was analyzed in JBK steers. Six of the 15 identified SNPs are novel and have never been registered in any public bovine SNP database. A non-synonymous SNP (rs211580559;C > T;294 Ala > Val) in exon 7 was examined in order to evaluate its association with fatty acid profiles. The data showed that highly significant association existed between rs211580559 and C18:2 (n-6) composition, and accounted for 22.3% of the variation. There were no significant relationships between rs2115-80559 and the other fatty acids. It was concluded that rs211580559 of the FADS2 gene may be a useful selection marker for reducing unfavorable volatiles generated from linoleic acid in JBK beef during the cooking process.

Cloning of Cotton Delta-12 Oleate Desaturase Gene FAD2-1 and Construction of Its ihpRNA and amiRNA Interference Vectors

Delta-12 oleate desaturase gene （FAD2-1） which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed.

Short-chain fatty acids act as antiinflammatory mediators by regulating prostaglandin E_2 and cytokines

AIM： To investigate the effect of short-chain fatty acids （SCFAs） on production of prostaglandin E2 （PGE2）, cytokines and chemokines in human monocytes. METHODS： Human neutrophils and monocytes were isolated from human whole blood by using 1-Step Polymorph and RosetteSep Human Monocyte Enrichment Cocktail, respectively. Human GPR41 and GPR43 mRNA expression was examined by quantitative realtime polymerase chain reaction, The calcium flux assay was used to examine the biological activities of SCFAs in human neutrophils and monocytes. The effect of SCFAs on human monocytes and peripheral blood mononuclear cells （PBMC） was studied by measuring PGE2, cytokines and chemokines in the supernatant. The effect of SCFAs in vivo was examined by intraplantar injection into rat paws. RESULTS： Human GPR43 is highly expressed in human neutrophils and monocytes. SCFAs induce robust calcium flux in human neutrophils, but not in human monocytes. In this study, we show that SCFAs can induce human monocyte release of PGE2 and that this effect can be enhanced in the presence of lipopolysaccharide （LPS）. In addition, we demonstrate that PGE2 production induced by SCFA was inhibited by pertussis toxin, suggesting the involvement of a receptor-mediated mechanism. Furthermore, SCFAs can specifically inhibit constitutive monocyte chemotactic protein-1 （MCP-1） production and LPS-induced interleukin-10 （IL-10） production in human monocytes without affecting the secretion of other cytokines and chemokines examined. Similar activities were observed in human PBMC for the release of PGE2, MCP-1 and IL-10 after 5CFA treatment. In addition, SCFAs inhibit LPS-induced production of tumor necrosis factor-α and interferon-7 in human PBIVlC. Finally, we show that SCFAs and LPS can induce PGE2 production in vivo by intraplantar injection into rat paws （P 〈 0.01）. CONCLUSION： SCFAs can have distinct antiinflammatory activities due to their regulation of PGE2, cytokine and chemokine release from human immune cells.

Fatty Acid Synthase and Hormone-sensitive Lipase Expression in Liver Are Involved in Zinc-α2-glycoprotein-induced Body Fat Loss in Obese Mice

Objective To explore the effects of zinc-0t2-glycoprotein （ZAG） on body weight and body fat in high-fat-diet （HF1））-induced obesity in mice and the possible mechanism. Methods Thirty-six male mice were fed with standard food （SF） （n=9） and HFD （n=27）, respectively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase （FAS） and hormone sensitive lipase （HSL） in liver tissue were deterlnined by reverse transcription-polymerase chain reaction. Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice （0.51±0.10 AU vs. 0.75±0.07 AU, P〈0.01）. Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight （r =-0.56, P〈0.001）, epididymal fat mass （r=-0.67, P〈O. 001）, percentage of epididymal fat （r= 0.65, P〈0.001）, and increased weight （r= 0.57, P〈0.001） in simple SF- and HFD fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididyreal fat. Furthermore, FAS mRNA expression decreased （P〈0.01） and HSL mRNA expression increased （P〈0.001） in the liver in ZAG over-expressing mice. Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and increased HSL expression in the liver of obese mice.

Functional characterization of a Δ6 fatty acid desaturase gene and its 5′-upstream region cloned from the arachidonic acid-rich microalga Myrmecia incisa Reisigl(Chlorophyta)

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.

楤木属FAD2基因家族的鉴定及生物信息学分析

聚炔类化合物(PAs)是一类主要由桔梗类植物产生、具生物活性的植物特异性防御物质。其上游合成步骤由脂肪酸去饱和酶2(FAD2)催化。本文以PA的主要来源植物之一,桔梗类的五加科楤木属(Aralia)为研究对象,对楤木(A.elata(Miq.)Seem.)和龙眼独活(A.fargesii Franch.)的FAD2基因家族进行鉴定,并对其保守基序、结构域、染色体分布、基因共线性、进化关系、分子演化速率以及表达情况进行分析。结果显示,楤木属的FAD2基因家族经历了广泛扩张,这可能是通过全基因组加倍/片段重复实现的;不同功能的FAD2保守基序完全一致,但楤木属不同生活型(草本vs.木本)代表物种FAD2的保守基序却产生了分化;楤木中可能有4个不同功能的FAD2基因,其在不同组织中的表达情况不同。本研究可为后续楤木属的物种鉴定、聚炔类物质合成新基因的挖掘以及桔梗类植物具高度多样化PAs分子机制的揭示提供参考。

Free fatty acids receptors 2 and 3 control cell proliferation by regulating cellular glucose uptake

BACKGROUND Colorectal cancer(CRC)is a worldwide problem,which has been associated with changes in diet and lifestyle pattern.As a result of colonic fermentation of dietary fibres,short chain free fatty acids are generated which activate free fatty acid receptors(FFAR)2 and 3.FFAR2 and FFAR3 genes are abundantly expressed in colonic epithelium and play an important role in the metabolic homeostasis of colonic epithelial cells.Earlier studies point to the involvement of FFAR2 in colorectal carcinogenesis.AIM To understand the role of short chain FFARs in CRC.METHODS Transcriptome analysis console software was used to analyse microarray data from CRC patients and cell lines.We employed short-hairpin RNA mediated down regulation of FFAR2 and FFAR3 genes,which was validated using quantitative real time polymerase chain reaction.Assays for glucose uptake and cyclic adenosine monophosphate(cAMP)generation was done along with immunofluorescence studies to study the effects of FFAR2/FFAR3 knockdown.For measuring cell proliferation,we employed real time electrical impedancebased assay available from xCELLigence.RESULTS Microarray data analysis of CRC patient samples showed a significant down regulation of FFAR2 gene expression.This prompted us to study the FFAR2 in CRC.Since,FFAR3 shares significant structural and functional homology with FFAR2,we knocked down both these receptors in CRC cell line HCT 116.These modified cell lines exhibited higher proliferation rate and were found to have increased glucose uptake as well as increased level of glucose transporter 1.Since,FFAR2 and FFAR3 signal through G protein subunit(Gαi),knockdown of these receptors was associated with increased cAMP.Inhibition of protein kinase A(PKA)did not alter the growth and proliferation of these cells indicating a mechanism independent of cAMP/PKA pathway.CONCLUSION Our results suggest role of FFAR2/FFAR3 genes in increased proliferation of colon cancer cells via enhanced glucose uptake and exclude the role of PKA mediated cAMP signalling.Alternate pathways could be involved that would ultimately result in increased cell proliferation as a result of down regulated FFAR2/FFAR3 genes.This study paves the way to understand the mechanism of action of short chain FFARs in CRC.

Genetic Variants in the ELOVL5 but not ELOVL2 Gene Associated with Polyunsaturated Fatty Acids in Han Chinese Breast Milk

The present study was designed to examine the contributions of the fatty acid elongase （ELOVL） gene polymorphisms to the levels of polyunsaturated fatty acids （PUFAs） in breast milk. Two hundred and nine healthy Han Chinese mothers were included in the study. Carriers of minor alleles of SNPs （rs2397142 and rs9357760） in ELOVL5 were associated with higher levels of linoleic acid （LA）, dihomo-γ-linolenic acid （DGLA）, arachidonic acid （AA）, docosatetraenoic acid （DTA）, docosahexenoic acid （DHA）, while in rs209512 of ELOVL5 the carriers of minor alleles had lower levels of DTA compared to major homozygote alleles （P ranged from 0.004-0.046）, and genetically explained variability ranged from 3.2% for eicosapentaenoic acid （EPA） to 6.0% for LA. Our findings demonstrated that common variation in ELOVL5 gene encoding rate-limiting enzymes in the metabolism of PUFAs contribute to the PUFAs in breast milk.

High-starchy carbohydrate diet aggravates NAFLD by increasing fatty acids influx mediated by NOX2

Nonalcoholic fatty liver disease(NAFLD)is a high-incidence lipid disorder that affects more than a quarter of the population worldwide,and dietary intervention is the recognized treatment.Starch is the main component of staple foods that are consumed daily,and the effects,metabolic pathway,and molecular mechanism of starch in the context of NAFLD remain unclear.Our study showed that a high-starch carbohydrate diet(HCD)led to the occurrence and exacerbation of NAFLD in mice.Transcriptomics and metabonomic analyses showed that the increased fatty acid influx mediated by NADPH oxidase 2(NOX2)exacerbated NAFLD.Knocking down NOX2 specifically alleviated HCD-induced NAFLD in vivo and in vitro.Moreover,the large amounts of ROS produced by NOX2 further exacerbated insulin resistance and increased lipolysis in perirenal white adipose tissue(periWAT),thereby providing fatty acids for hepatic lipid synthesis.In addition,the interaction between AMPKα1 and p47phox was the pathway that mediated the high expression of NOX2 induced by a HCD.Our study systematically demonstrated the effect of a HCD on NAFLD.Elevated fatty acid influx is a unique molecular regulatory pathway that mediates HCD-induced NAFLD exacerbation,which is different from the effect of simple sugars.Additionally,NOX2 was suggested to be a specific and effective drug target for NAFLD.

Effect of diacylglycerol acyltransferase 2overexpression in 3T3-L1 is associated to an increase in mono-unsaturated fatty acid accumulation

Background：Fatty acid（FA） composition is the most important parameter affecting the flavor and nutritional value of the meat.The final and the only committed step in the biosynthesis of triglycerides is catalyzed by diacylglycerol acyltransferase 2（DGAT2）.The role of DGAT2 in lipid accumulation has been demonstrated in adipocytes,However,little is known about the effect of DGAT2 on the FA composition of these cells.Methods：To investigate the role of DGAT2 in regulating lipid accumulation,FA composition and the expression of adipogenic genes,we cloned the open reading frame of the porcine DGAT2 gene and established 3T3-L1 cells that overexpressed DGAT2.Cells were then cultured in differentiation medium（DM） without FA,with a mixture of FAs（FA-DM）,or containing a ^（13）C stable isotope-labeled FA mixture（IFA-DM）.The FA composition of adipocytes was analyzed by gas chromatography-mass spectrometry and gas chromatography-isotope ratio mass spectrometry.Quantitative PCR and western blotting were employed to detect expression of adipogenic genes in 3T3-L1 adipocytes cultured with FA-DM for 12 d.Results：The triacylglyceride（TAG） content was significantly higher in 3T3-L1 adipocytes overexpressing DGAT2 than in control cells.When cultured in DM or FA-DM for 12 d,cells overexpressing DGAT2 showed a higher proportion of unsaturated FAs（C16：1 and C18：1）.However,when cells overexpressing DGAT2 were cultured with FA-DM for30 min,the FA composition was almost identical to that of controls.Further,the proportion of stable isotope-labeled FAs were similar in 3T3-L1 adipocytes overexpressing DGAT2 and control cells cultured in IFA-DM for 12 d.These results collectively indicate that the higher proportion of mono-unsaturated FAs,C16：1 and C18：1,may originate from de novo FA synthesis but not from the uptake of specific FAs from the medium.This hypothesis is further supported by evidence that both mRNA and protein expression of genes involved in FA synthesis（ACACA,FASN,SCD1,and A-FABP）were significantly higher in cells overexpressing DGAT2 than in control cells.Conclusions：In conclusion,our study revealed that TAG accumulation,the proportion of MUFAs,and the expression of adipogenic genes were higher in 3T3-L1 cells overexpressing DGAT2 than in control cells.

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.

Influence of gut bacteria on type 2 diabetes:Mechanisms and therapeutic strategy

The onset and progression of type 2 diabetes mellitus(T2DM)are strongly associated with imbalances in gut bacteria,making the gut microbiome a new potential therapeutic focus.This commentary examines the recent publication in World Journal of Diabetes.The article explores the association between T2DM and gut microbiota,with a focus on the pathophysiological changes related to dysbiosis.It proposes innovative microbiome-targeted therapeutic strategies and evaluates the challenges and future directions of such approaches.This editorial summarizes the key points of their discussion of the role of the gut microbiome in T2DM and elaborates on the influence of specific gut microbial species on the disease through the host–microbiota metabolic axis.It provides new insights for future research on gut-microbiota-based interventions for T2DM.

Biotechnology ofα-linolenic acid in oilseed rape(Brassica napus)using FAD2 and FAD3 from chia(Salvia hispanica)

α-Linolenic acid(ALA,18:3Δ9,12,15)is an essential fatty acid for humans since it is the precursor for the biosynthesis of omega-3 long-chain polyunsaturated fatty acids(LC-PUFA).Modern people generally suffer from deficiency of ALA because most staple food oils are low or lack ALA content.Biotechnological enrichment of ALA in staple oil crops is a promising strategy.Chia(Salvia hispanica)has the highest ALA content in its seed oil among known oil crops.In this study,the FAD2 and FAD3 genes from chia were engineered into a staple oil crop,oilseed rape(Brassica napus),via Agrobaterium tumefaciens-mediated transformation of their LP4-2A fusion gene construct driven by the seed-specific promoter P_(NapA).In seeds of T0,T1,and T2 lines,the average ALA contents were 20.86,23.54,and 24.92%,respectively,which were 2.21,2.68,and 3.03 folds of the non-transformed controls(9.42,8.78,and 8.22%),respectively.The highest seed ALA levels of T0,T1,and T2 plants were 38.41,35.98,and 39.19%respectively,which were 4.10-4.77 folds of the respective controls.FA-pathway enzyme genes(BnACCD,BnFATA,BnSAD,BnSCD,BnDGAT1,BnDGAT2,and BnDGAT3)and positive regulatory genes(BnWRI1,BnLEC1,BnL1L,BnLEC2,BnABI3,BnbZIP67,and BnMYB96)were all significantly up-regulated.In contrast,BnTT1,BnTT2,BnTT8,BnTT16,BnTTG1,and BnTTG2,encoding negative oil accumulation regulators but positive secondary metabolism regulators,were all significantly down-regulated.This means the foreign ShFAD2-ShFAD3 fusion gene,directly and indirectly,remodeled both positive and negative loci of the whole FA-related network in transgenic B.napus seeds.

血清游离脂肪酸和心型脂肪酸结合蛋白表达与2型糖尿病病人动脉粥样硬化斑块的关系研究

目的探讨血清游离脂肪酸(FFA)和心型脂肪酸结合蛋白(H-FABP)表达与2型糖尿病(T2DM)病人动脉粥样硬化斑块(CAP)的关系研究。方法选取2020年6月至2022年6月保定市第四中心医院接收的T2DM病人302例为研究对象。通过颈动脉超声检查进一步将研究对象分为CAP组(165例)和无CAP组(137例)。采用酶联免疫吸附测定(ELISA)检测血清FFA、H-FABP水平;采用logistic多因素回归分析CAP发生的影响因素;采用Spearman法分析血清FFA、H-FABP水平及与临床资料的相关性分析;采用受试者操作特征曲线(ROC曲线)评价血清FFA、H-FABP及其联合对CAP发生的诊断效能。结果相较于无CAP组,CAP组年龄、高血压史、C反应蛋白(CRP)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL)、载脂蛋白A(ApoA)、FFA、H-FABP[(4.63±1.43)μg/L比(3.68±1.05)μg/L]水平显著上升(P<0.05),LPa水平显著下降(P<0.05)。logistic分析显示,年龄、CRP、TG、LDL、FFA、H-FABP均是T2DM病人CAP发生的独立危险因素(P<0.05)。T2DM合并CAP病人血清FFA与H-FABP、年龄、CRP、TG、LDL水平呈正相关(rs=0.61、0.59、0.52、0.57、0.55,P<0.05)。血清H-FABP与年龄、CRP、TG、LDL水平呈正相关(rs=0.58、0.53、0.57、0.54,P<0.05)。ROC曲线结果显示血清中FFA、H-FABP水平及二者联合预测T2DM病人CAP发生的AUC分别为0.71、0.74、0.84,其中联合预测AUC显著高于二者单独预测AUC(Z=3.65、2.68,P<0.05)。结论FFA、H-FABP水平在T2DM合并CAP病人血清中升高,与年龄、CRP、TG、LDL关系密切,均有望成为T2DM病人CAP发生的诊断因子。

Comparison of the fatty acid composition of the serum phospholipids of controls, prediabetics and adults with type 2 diabetes

Objective: Although abnormalities in the fatty acid composition of serum and red cell membrane phospholipids of patients with type 2 diabetes are well-documented, lacking are studies of this issue in prediabetic individuals. Materials/Methods: For this cross-sectional study, we recruited 180 subjects (30 - 80 years), 56 of whom were normal with regard to glucose control (HbA1c, 6.5%). Serum phospholipids were isolated and analyzed for fatty acids. Results: Most importantly, the fatty acid compositions of the controls and prediabetic subjects were not different for 19 fatty acids. However, the fatty acid profile of the phospholipids of the patients with diabetes differed from the other two groups;the 14 to 18-carbon saturated fatty acids were decreased by 12% - 26% whereas the unsaturated fatty acids 16:1n-7, 18:1n-9, 18:2n-6, 20:3n-6 and 20:4n-6 were increased by 45% - 64%. Of note, the docosahexaenoic acid (DHA) status of individuals in all three study groups was remarkably low compared with international values, as indicated by DHA proportions in the 1.62% - 2.07% range, and there were no differences between groups. The mean melting point of the phospholipid fatty acids of the diabetic patients (32.2℃) was significantly lower (p < 0.001) than that of the prediabetic subjects (38.1℃) and the controls (39.9℃) which were not different from each other. Conclusion: These observations indicate that the fatty acid changes associated with type 2 diabetes follow the onset of the disease as opposed to being a causative factor of poor glucose control and insulin insensitivity.

Type 2 diabetes with good glycemic control have improved insulin response and lower non-esterified fatty acid level after a meal challenge

Background: Pathogenesis of type 2 diabetes (T2DM) involves defects in β-cell function with impaired first and second phase insulin response, and reduced insulin sensitivity. Diabetic dyslipidemia is an important and common risk factor for coronary heart disease (CHD). Aims: This study examined the effect of glycemic control on post prandial insulin and lipid parameters in response to a standardised meal challenge among Type 2 diabetes patients with good and poor glycemic control. Methods: We cross-sectionally studied 31 T2DM patients with good glycemic control and 32 T2DM patients with poor glycemic control. Subjects were given, after minimum 10 hours of fasting, a standard meal containing 58% fat. Fasting and serial postprandial blood samples were taken over 8 hours to determine levels of triglyceride, direct LDL-C, apoB lipoprotein, non-esterified-fatty-acid, insulin and blood glucose. Results: Post prandial NEFA was significantly higher in poor controlled diabetes patients compared to good control diabetes patients (p = 0.019), and post-hoc analysis showed significant difference from 3 hours post prandial to 4 hours post prandial, where p= 0.021. Although the difference in insulin between the 2 groups did not reach statistical significance (p =0.058), post-hoc analysis showed significant difference between the 2 groups from fasting to 1 hour post prandial (p = 0.034) despite postprandial glucose being significantly higher in poor controlled diabetes patients (p < 0.001), throughout the postprandial period. Conclusion: T2DM patients with good glycemic control have improved insulin response with lower non-esterified fatty acid.

Relationship between Ethanol and 2-phenylethanol Stress Tolerance and Fatty Acid Compositions of Saccharomyces cerevisiae

In the present study, we investigated of the ethanol （Eth）, 2-phenylethanol （2-PE） and ethanol/2-phenylethanol （Eth/2-PE） stress tolerance and established relationship between stress tolerance and fatty acid compositions of wine yeast strain S. cerevisiae UCM Y-524 in relation to different cultivation factors. Changes in cell membrane fatty acid profiles studied under different temperature and media. The active oxygenation, semi-aerobic cultivation supplemented Tween 80 conditions were used in different combinations. The concentrations of 2-PE and Eth, the fatty acids methyl esters （FAMES） in the media were measured by GC-MS analyses. 2-PE, Eth, FAMES were identified by NIST02 MS database at the 2-PE and Eth standard solution （Merck, Germany）, bacterial FAMES standard （Supelco）. Palmitoleic and oleic acid were dominated for S. cerevisiae UCM Y-524. The unsaturated/saturated fatty acid （UFA/SFA） ratio was higher than five for S. cerevisiae UCM Y-524 at 14 ~C in simple medium and about more than three for other conditions. It has been found that yeast cells grown in the presence of the 2-PE, Eth and Eth/2-PE appear to increase the amount of unsaturated fatty acids, especially oleic acid, in cellular lipids especially under active oxygenation supplemented with Tween 80. S. cerevisiae UCM Y-524 has a higher tolerance under 2-PE, Eth and Eth/2-PE stress at 28 ~C in a simple medium under aerobic conditions. A higher concentration of unsaturated fatty acids in the membrane S. cerevisiae UCM Y-524 and a lower temperature under aerobic conditions, has been considered to have a positive influence on the excretion of 2-phenylethanol.