PPARγ agonist-induced alterations in Δ6-desaturase and stearoyl-CoA desaturase 1:Role of MEK/ERK1/2 pathway

AIM:To investigate the effect of MEK/ERK1/2 pathway on peroxisome proliferator-activated receptors(PPARγ)agonist-induced alterations in Δ6-desaturase(Δ6D)and stearoyl-CoA desaturase 1(SCD1)in hepatocellular carcinoma cell line HepG2.METHODS:HepG2 cells cultured in RPMI-1640 were exposed to the commonly used ERK1/2 pathway inhibitor PD98059 and PPARγ agonist,pioglitazone.Total RNA was isolated and reverse transcribed from treated cells.Changes in gene expression and metabolites ratio,as activity index for Δ6D and SCD1,were then determined using reverse transcriptionpolymerase chain reaction and gas liquid chromatography,respectively.RESULTS:The expression of both Δ6D(P = 0.03)and SCD1(P = 0.01)increased following PD98059 treatment,with a higher impact on SCD1(24.5%vs 62.5%).Although pioglitazone increased the mRNA level(1.47 ± 0.10 vs 0.88 ± 0.02,P = 0.006)and activity index(1.40 ± 0.07 vs 0.79 ± 0.11,P < 0.001)of Δ6D,no such changes have been observed for SCD1 activity index in pioglitazone-treated cells.SCD1 gene expression(+26.4%,P = 0.041)and activity index(+52.8%,P = 0.035)were significantly increased by MEK inhibition in the presence of pioglitazone,as compared with pioglitazone alone and control cells.However,the response of Δ6D expression and activity index to pioglitazone was unaffected by incubation with PD98059.CONCLUSION:PPARγ and ERK1/2 signaling pathway affect differentially and may have inhibitory crosstalk effects on the genes expression of 6D and SCD1,and subsequently on their enzymatic activities.

Fatty acid desaturation by stearoyl-CoA desaturase-1 controls regulatory T cell differentiation and autoimmunity

The imbalance between pathogenic and protective T cell subsets is a cardinal feature of autoimmune disorders such as multiple sclerosis(MS).Emerging evidence indicates that endogenous and dietary-induced changes in fatty acid metabolism have a major impact on both T cell fate and autoimmunity.To date,however,the molecular mechanisms that underlie the impact of fatty acid metabolism on T cell physiology and autoimmunity remain poorly understood.Here,we report that stearoyl-CoA desaturase-1(SCD1),an enzyme essential for the desaturation of fatty acids and highly regulated by dietary factors,acts as an endogenous brake on regulatory T-cell(Treg)differentiation and augments autoimmunity in an animal model of MS in a T cell-dependent manner.Guided by RNA sequencing and lipidomics analysis,we found that the absence of Scd1 in T cells promotes the hydrolysis of triglycerides and phosphatidylcholine through adipose triglyceride lipase(ATGL).ATGL-dependent release of docosahexaenoic acid enhanced Treg differentiation by activating the nuclear receptor peroxisome proliferator-activated receptor gamma.Our findings identify fatty acid desaturation by SCD1 as an essential determinant of Treg differentiation and autoimmunity,with potentially broad implications for the development of novel therapeutic strategies and dietary interventions for autoimmune disorders such as MS.

Construction of a High-efficient Expression Vector of Δ^(12) Fatty Acid Desaturase in Peanut and Its Prokaryotical Expression

A full-length sequence coding for △^12 fatty acid desaturase gene from peanut（Arachis hypogaea L.）was cloned into the expression vector, pRSETB, to generate recombinant plasmid pRSET/HO-A, which was subsequently transformed into expression Escherichia. coli BL21（DE3）pLysS. The △^12 fatty acid desaturase was highly expressed in E. coli BL21（DE3）pLysS in the presence of isopropyl-D-thiogalactopyranoside （IPTG）. The fusion protein was purified and used to form a reaction system in vitro by adding oleic acid as substrate and incubating it at 20℃ for 6 h. Total fatty acids was extracted and methlesterified and then analyzed with gas chromatography. A novel peak corresponding to linoleic acid methyl ester standards was detected with the same retention time. GC-MS （gas chromatogram and gas chromatogram-mass spectrometry） analysis showed that the novel peak was linoleic acid methyl ester. These results exhibited △^12 fatty acid desaturase activity, which could convert oleic acid to linoleic acid specifically.

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.

Comparison of the Δ^(12) fatty acid desaturase gene between high-oleic and normal-oleic peanut genotypes

△^12 fatty acid desaturase gene has been targeted as a logical candidate controlling the high oleate trait in peanut seeds. By RT-PCR method, the full-length cDNAs of △^12 fatty acid desaturase gene were isolated from peanut （Arachis hypogaea L.） genotypes with normal and high ratio of oleic to linoleic acid, which were designated AhFAD2B and AhFAD2B＇, respectively. Sequence alignment of their coding regions revealed that an extra A was inserted at the position ＋442 bp of AhFAD2B＇ sequence of high oleic acid genotypes, which resulted in the shift of open reading frame and a truncated protein AhFAD2B＇, with the loss of one histidine box involved in metal ion complex required for the reduction of oxygen. Analysis of transcript level showed that the expression of △^12 fatty acid desaturase gene in high oleic acid genotype was slightly lower than that in normal genotype. The enzyme activity experiment of yeast （Saccharomyces cerevisiae） cell transformed with AhFAD2B or AhFAD2B＇ proved that only AhFAD2B gene product showed significant △^12 fatty acid desaturase activity, but AhFAD2B＇ gene product did not. These results suggested that the change of AhFAD2B＇ gene sequence resulted in lower activity or deactivation of △^12 fatty acid desaturase in high oleic acid genotype.

Disruption of phytoene desaturase gene results in albino and dwarf phenotypes in Arabidopsis by impairing chlorophyll, carotenoid, and gibberellin biosynthesis

Carotenoids play an important role in many physiological processes in plants and the phytoene desaturase gene （PDS3） encodes one of the important enzymes in the carotenoid biosynthesis pathway. Here we report the identification and analysis of a T-DNA insertion mutant of PDS3 gene. Functional complementation confirmed that both the albino and dwarfphenotypes ofthepds3 mutant resulted from functional disruption of the PDS3 gene. Chloroplast development was arrested at the proplastid stage in thepds3 mutant. Further analysis showed that high level ofphytoene was accumulated in the pds3 mutant. Addition of exogenous GA3 could partially rescue the dwarf phenotype, suggesting that the dwarf phenotype ofthepds3 mutant might be due to GA deficiency. Microarray and RT-PCR analysis showed that disrupting PDS3 gene resulted in gene expression changes involved in at least 20 metabolic pathways, including the inhibition of many genes in carotenoid, chlorophyll, and GA biosynthesis pathways. Our data suggest that the accumulated phytoene in the pds3 mutant might play an important role in certain negative feedbacks to affect gene expression of diverse cellular pathways.

Cloning and characterization of a stearoyl-ACP desaturase gene from Jatropha curcas

Using degenerate primers and RT-PCR, RACE techniques, a 1491 bp cDNA segment of stearoyl-acyl carrier protein desaturase （SAD） is cloned from developing seeds of Jatropha curcas L. The segment contains a 1191 bp of complete open reading frame （ORF）. Analysis in the BLAST on NCBI shows that Jatropha curcas SAD （JSAD） gene encodes a protein precursor composed of a signal peptide of 33 amino acids and a mature peptide of 363 amino acids. The homological analysis shows that JSAD has high level of homology both in nucleotide sequence and in amino acid sequence to other plants SADs. The nucleotide and peptide identity of JSAD to Ricinus communis SAD （RSAD） is up to 89% and 96.2% respectively. Molecular modeling of JSAD indicates that its three-dimensional structure strongly resembled the crystal structure of RSAD.

Cloning and characterization of a delta-6 desaturase encoding gene from Nannochloropsis oculata

A gene （NANOC-D6D） encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata （Droop） D. J. Hibberd （Eustigmatophyceae）. The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids （LCPUFAs）, including eicosapentaenoic acid （20：5n-3, EPA）. The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVScl to verify the substrate specificity of NAN OC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid （LA） and a-linolenic acid （ALA）.

Identification and characterization of a delta-12 fatty acid desaturase gene from marine microalgae Isochrysis galbana

The cDNA of the delta-12 fatty acid desaturase gene, IgFAD2, was cloned from the marine microalgae Isochrysis galbana, a species capable of producing docosahexaenoic acid. Sequence analysis indicated that the open reading frame measured a length of 1 158 bp and encoded 386 amino acids with a predicted molecular weight of 42.8 kDa and an isoelectric point of 9.2. Computational analysis of the protein sequence of IgFAD2 showed typical features of membrane-bound desaturase such as three conserved histidine boxes along with four membranespanning regions that were universally present among plant desaturases. Quantitative real-time PCR results showed that the abundance of IgFAD2 transcript was significantly upregulated under different environmental stresses including low temperature(15℃), high salinity(salinity of 62 and 93), and nitrogen starvation(220 μmol/L). Heterologous expression indicated that yeast cells transformed with a plasmid construct containing IgFAD2 could convert endogenous oleic acid(18:1^(?9), OA) into linoleic acid(18:2^(?9, 12), LA). These findings confirm that I. galbana IgFAD2 plays important roles in the biosynthetic pathways of unsaturated fatty acids.

Production of γ-linolenic acid and stearidonic acid by Synechococcus sp.PCC7002 containing cyanobacterial fatty acid desaturase genes

Genetic modifi cation is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. S ynechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid(GLA) and stearidonic acid(SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6 D, Syd15 D and Syd6Dd15 D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in S ynechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.

Cloning and molecular characterization of△^(12)-fatty acid desaturase gene from Mortierella isabellina

AIM： To clone △^12 -fatty acid desaturase gene of Mortierella isabellina and to functionally characterize this gene in vitro and in vivo.METHODS： Reverse transcriptional polymerase chain reaction （RT-PCR） was used to clone the open reading frame of △^12-fatty acid desaturase gene （D12D） of Mortierella isabellina. Plasmids pEMICL12 and pYMICL12 were constructed with it. pEMICL12 was transformed into Escherichia coli（E.coli） strain BL21 using CaCl2 method for expression after induction with IPTG. pTMICL12 was transformed into Saccharomyces cerevisiae strain IN- VSc1 using lithium acetate method for expression under the induction of galactose. Northern blotting method was used to investigate the effect of temperature on the transcriptional level of this gene in S.cerevisiae strain IN- VSc1.RESULTS： Recombinant plasmids pEMICL12 and pTMICL12 were successfully constructed and transformed into E. coli and S.cerevisiae separately with appropriate method. After induction with IPTG and galactose, it was found that expression of △^12-fatty acid desaturase genes in E.coli and S. cerevisiae under appropriate conditions led to the production of active △^12-fatty acid desaturase, which could convert 17.876% and 17.604% of oleic acid respectively to linoleic acid by GC-MS detection in vitro and in vivo.CONCLUSION： Cloning and expression of M.isabellina D12D gene in E.coli and S.cerevisiae is successfully completed.

Identification and Functional Characterization of a NovelΔ12 Fatty Acid Desaturase Gene from Haematococcus pluvialis

The freshwater microalga Haematococcus pluvialis accumulates large amounts of fatty acids in response to adverse conditions.However,the key fatty acid desaturase genes in H.pluvialis remain unknown.In this study,we cloned and functionally characterized aΔ12 fatty acid desaturase gene,and designated it as HpFAD2.The open reading frame of HpFAD2 consisted of 1137 base pairs and encoded 378 amino acids.The deduced polypeptide showed 70%identity to other endoplasmic reticulumΔ12 fatty acid desaturases,whereas it had only 44%identity to plastidΔ12 fatty acid desaturases.The PSORT algorithm and phylogenetic analysis further confirmed its affiliation to the endoplasmic reticulumΔ12 fatty acid desaturases.Heterologous expression was performed in Saccharomyces cerevisiae cells transformed with the recombinant plasmid pYES2-HpFAD2.Two additional fatty acids(C16:2 and C18:2)were detected in the yeast transformants.The results indicatedΔ12 desaturation activity and substrate preference for C18:1 over C16:1.The transcriptional levels of H.pluvialis HpFAD2 at different growth stages were measured by quantitative polymerase chain reaction(PCR),indicating that the HpFAD2 transcriptional levels were significantly higher in red cells than those in green cells.Our study brings more insight into the fatty acid biosynthetic pathway of H.pluvialis.

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.

Cloning and Characterization of the Phytoene Desaturase(pds) Gene-a Key Enzyme for Carotenoids Synthesis in Dunaliella(Chlorophyta)

The unicellular green alga Dunaliella is outstanding for its ability of massive accumulation of carotenoids. To elucidate the carotenoids synthesis pathway in this alga,phytoene desaturase(pds) gene cDNA together with its DNA sequences were isolated and their structures and functions analyzed. The full-length pds cDNA of 2290 bp(GenBank Accession No. DQ243892) was de-duced from RACE results,including untranslated 21 bp 5'-and 520 bp 3'-flanking regions and an open reading frame of 582 amino acids,coding a protein of 64.196 kDa. The DNA sequence of 2908 bp(GenBank Accession No. DQ845248) including five introns was obtained. The fifth intron was uncompleted and complex,including two bases' perfect repeats(GT) 10 and large different-sized repeats within the last 400 bp. The Southern blot hybridization result demonstrated that this gene occurred as a single copy in this species,and the quantitative RT-PCR result showed that the transcription of this gene was constitutive. The evolutional significance of pds was discussed.

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.

Mutagenesis of Arachidonic Acid-producing Mortierella Isabellina and Analyses of Δ~6-desaturase Role by qPCR

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.

Cloning, Expression of Crocus sativus Phytoene Desaturase Gene and Preparation of Antiserum against It

A 2 149 bp full length phytoene desaturase (PDS) cDNA was first cloned from saffron (Crocus sativus L.) stigma using RT-PCR technique and a rapid amplification of cDNA end (RACE) strategy. The cDNA has an open reading frame of 1 697 bp, which encodes a polypeptide of 565 amino acids. The coding region of the cDNA was inserted into a prokaryotic expression vector pET-21a(+) and over-expressed inE. coli BL21 (DE3). The fusion proteins were found largely in an insoluble inclusion bodies. The purified fusion protein was used to immunize rabbits to obtain polyclonal antiserum with titer of 1×105. Western blot analysis by using this particular antiserum showed that the higher expression level of PDS in mature stigma than in leaves and stamen, and the higher expression level of PDS in mature stigma than in young stigma. Key words saffron - carotenoids - phytoene desaturase - gene expression - antiserum - Western blot CLC number Q 781 - Q 786 Foundation item: Supported by the Doctoral Foundation of the Ministry of Education, P. R. China and the Young Science Foundation of Sichuan University (Grant 0020405505012)Biography: Bai Jie (1968-), female, Ph. D candidate, research direction: plant developmental biology and reproductive engineering.

Origin and evolution of fatty acid desaturase genes in oil crop Brassica napus

Fatty acid(FA)desaturases,as the key enzymes in lipid metabolism,are responsible for biosynthesis of the unsaturated fatty FAs,which play important roles in maintaining cell membrane integrity and multiple stress responses.Although attention has been drawn to some plant FA desaturase genes,their global landscape in oil crops is still lacking.Here,we performed systematic characterization and phylogenomic synteny network analyses of the FA desaturase gene family in polyploid oil crop B.napus and other 54 species covering major streptophyte lineages.A total of 1653 FA desaturase genes were identified from these plant genomes.Based on the broad-scale family phylogeny and functional domains,we proposed a unified eight-group classification system for angiosperm FA desaturases,and found that the origin of genes responsible for FA desaturation evolved early and some genes were absent in different species.Phylogenomic analyses revealed deeply conserved syntenic relationships within each of the eight FA desaturase groups.B.napus contains up to 93 FA desaturase genes from the eight groups.Recurrent duplication events in Brassicaceae contributed to the expansion of FA desaturase genes in B.napus,leading to further functional diversification.These FA desaturase genes exhibited spatio-temporal specific expression patterns in different tissues of B.napus,and a set of FA desaturase genes seem to be orchestrated by key transcriptional factors during seed development,such as zf-HD,B3,GATA3,PEI1,NFYA7,YAB1 and YAB2.Altogether,our data have inferred the evolutionary trajectory of this important gene family across distinct plant lineages,providing theoretical basis for future manipulation of FA desaturase genes to improve the seed oil quality of B.napus.

The Effect of Parity on Conjugated Linoleic Acid(CLA) Content in Milk Fat and CLA-Desaturase Index from Holstein Dairy Cows

The performance of lactating dairy cows and composition of the fatty acids in milk fat were measured to investigate the effect of parity on conjugated linoleic acid(CLA)in milk fat and△~9-desaturase indices from Holstein dairy cows.Milk samples of two hundred and thirty-five lactating Holstein dairy cows in north China were tested.In order to avoid possible confounding effects of diet and season,Holstein cows were fed a single diet and milk was sampled on the same day.The average content of cis-9,trans-11 CLA was 5.14 mg/g fatty acids in milk fat,varying between 1.5 and 10.5 mg/g fatty acids.The average content of cis-9,trans-11 CLA of primiparous cattle was 5.19 mg/g fatty acids in milk fat,while it was 5.11 mg/g fatty acids in multiparous animals,with no significant difference between them(P】0.05).There was a significant(P【0.05)difference between the△~9-desaturase index of cis-9 C14:l and cis-9 C16:l between primiparous and multiparous cattle but not(P】0.05)in the△~9-desaturase index of cis-9 C18:l and cis-9,trans-11 CLA.

温胆汤对肥胖代谢相关基因B4 galt7、Sc5d启动子甲基化及表达的影响

目的 分析中医化痰名方温胆汤对肥胖腹腔脂肪组织代谢相关基因B4 galt7、Sc5d启动子区甲基化及表达的影响。方法 首先采用高脂饲料喂养构建肥胖大鼠模型,通过高、中、低不同剂量温胆汤干预肥胖大鼠,观察药物减重降脂的效应;然后采用Massarray技术检测B4Galt7、Sc5d基因启动子甲基化情况;再分别利用实时荧光定量RT-PCR技术、蛋白质印迹技术检测B4Galt7、Sc5d基因的表达情况,分析启动子区甲基化情况与表达间的关系。结果 (1)温胆汤的干预效果与药物浓度无明显剂量依赖关系,高、中剂量温胆汤对肥胖大鼠具有较好减轻体质量作用;温胆汤对改善肥胖大鼠的血脂中TG、TC、LDL-C水平有积极意义,尤其以高剂量组明显。(2)B4 galt7基因启动子区共检测到有31个位点发生甲基化改变。空白对照组与正常对照组比较平均甲基化程度上升,其中有24个位点甲基化程度上升。在此24个位点中,各药物组基本呈现与空白组相对的调控方向,即甲基化程度较空白对照组下降;Sc5d基因启动子区共检测到有37个位点发生甲基化改变。空白对照组与正常对照组比较平均甲基化程度下降,其中有20个位点甲基化程度下降。在此20个位点中,各药物组基本呈现与空白对照组相对的调控方向,即甲基化程度较空白对照组上升。(3)空白对照组与正常对照组相比B4Galt7 mRNA表达降低,但差异无统计学意义(P>0.05);温胆汤干预后,各药物组表达低于空白对照组,但组间均无统计学差异(P>0.05);空白对照组与正常对照组相比Sc5d mRNA表达增高,差异具有统计学意义(P<0.05);温胆汤干预后,各药物组与空白对照组比较表达降低,其中药物中剂量组降低明显,具有统计学差异(P<0.05)。(4)空白对照组与正常对照组比较,B4Galt7、Sc5d蛋白表达升高明显(P<0.01)。温胆汤干预后,各药物组B4Galt7、Sc5d蛋白表达明显低于空白对照组,且差异存在统计学意义(P<0.01)。结论 温胆汤对B4Galt7基因启动子甲基化程度的影响均与其表达无明显关系,而对Sc5d基因启动子的甲基化的影响与其表达有相关性。