To investigate the effect of Gegen Qinlian Decoction(GQD) on enzyme activity, gene expression and methylation level of fatty acid synthase(FASN) in adipose tissue from rats with insulin resistance induced by high-fat diet. The 60% fat-powered high-fat diet was continuously given to male SD rats to induce the insulin resistance model. Then, they were divided into five groups randomly and administrated by gavage every day for 16 weeks with following drugs respectively: 10 mL·kg~(-1)water for control group(C) and insulin resistance model control group(IR), 1.65 g·kg~(-1)GQD per day for low-dose group(GQDL), 4.95 g·kg~(-1)GQD per day for medium-dose group(GQDM), 14.85 g·kg~(-1)GQD per day for high-dose group(GQDH), and 5 mg·kg~(-1) rosiglitazone per day for rosiglitazone group(RGN). Epididymal adipose tissue was taken to determine enzyme activity of FASN by colorimetric method, mRNA expression level of Fasn by quantitative Real-time PCR(Q-PCR) and CpGs methylation level between +313 and +582 by bisulfite sequencing PCR(BSP). These results showed that Fasn expression was significantly lowered in IR model rats compared with the control rats(P<0.01). Enzymatic activity and CpGs methylation level of Fasn in IR group showed downward trends. Low and medium-dose GQD can increase enzyme activity of FASN(P<0.05). Moreover, low-dose GQD increased the total CpGs methylation level of Fasn fragment between +313 and +582 in insulin resistance rats(P<0.05). For GQDM group, the methylation frequency of CpGs at positions +506 and +508(P<0.01) as well as the methylation frequency of CpGs on the binding sites of transcription factorzinc finger protein 161(P<0.05) were significantly increased. The methylation frequency of CpG at +442 position was positively correlated with Fasn expression(P<0.01, r=0.735), and methylation frequencies of CpGs at +345 and +366 positions were positively associated to enzyme activity of FASN respectively(P<0.05, r=0.479; P<0.01, r=0.640). In conclusion, GQD can reverse enzyme activity of FASN and methylation level of Fasn in adipose tissue of insulin resistant rats, and CpG sites at positions +506 and +508 may be the targets of GQD. The methylation level of CpGs at + 345 and + 366 sites were possibly related to FASN activity, while methylation of CpG at + 442 site may be closely correlated with mRNA level of Fasn. In addition, GQD did not significantly change mRNA expression level of Fasn, but effectively reversed enzymatic activity, suggesting that GQD may regulate the post transcriptional expression of Fasn.
Adipose Tissue ; Animals ; Drugs, Chinese Herbal ; Fatty Acid Synthases/genetics* ; Gene Expression ; Insulin Resistance/genetics* ; Male ; Methylation ; Rats ; Rats, Sprague-Dawley

Three long-chain polyunsaturated fatty acids, docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6), are the most biologically active polyunsaturated fatty acids in the body. They are important in developing and maintaining the brain function, and in preventing and treating many diseases such as cardiovascular disease, inflammation and cancer. Although mammals can biosynthesize these long-chain polyunsaturated fatty acids, the efficiency is very low and dietary intake is needed to meet the requirement. In this study, a multiple-genes expression vector carrying mammalian A6/A5 fatty acid desaturases and multiple-genes expression vector carrying mammalian Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases coding genes was used to transfect HEK293T cells, then the overexpression of the target genes was detected. GC-MS analysis shows that the biosynthesis efficiency and level of DHA, EPA and ARA were significantly increased in cells transfected with the multiple-genes expression vector. Particularly, DHA level in these cells was 2.5 times higher than in the control cells. This study indicates mammal possess a certain mechanism for suppression of high level of biosynthesis of long chain polyunsaturated fatty acids, and the overexpression of Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases broke this suppression mechanism so that the level of DHA, EPA and ARA was significantly increased. This study also provides a basis for potential applications of this gene construct in transgenic animal to produce high level of these long-chain polyunsaturated fatty acid.
Acetyltransferases ; genetics ; metabolism ; Arachidonic Acid ; biosynthesis ; Docosahexaenoic Acids ; biosynthesis ; Eicosapentaenoic Acid ; biosynthesis ; Fatty Acid Desaturases ; genetics ; metabolism ; Fatty Acid Synthases ; genetics ; metabolism ; Fatty Acids, Unsaturated ; biosynthesis ; Genetic Vectors ; HEK293 Cells ; Humans ; Transfection

Fatty acid synthase (FAS) catalyses the reaction between acetyl-CoA and malonyl-CoA to produce fatty acids. It is one of the most important enzyme in lipid biosynthesis. FAS of the oleaginous yeast Rhodosporidium toruloides has two acyl carrier protein (ACP) domains and a distinct subunit composition compared with FASs of other species. As ACP is a protein cofactor crucial for fatty acid chain elongation, more ACPs in the FAS may facilitate the reaction. To study the biochemical and structural properties of this novel FAS from R. toruloides, plasmids were constructed and transformed into Escherichia coli BL21 (DE3). The strain ZWE06 harboring plasmids pET22b-FAS1 and pET24b-FAS2 could co-overexpress the two subunits. The recombinant FAS was purified by sequentially using ammonium sulphate precipitation, sucrose density gradient centrifugation and anion exchange chromatography. The specific activity of the recombinant FAS was 548 mU/mg. The purified complex would be used to study enzyme kinetics and protein structure of FAS, and heterogeneous expression and purification will facilitate revealing the mechanism of this novel FAS with double ACPs.
Acyl Carrier Protein ; Basidiomycota ; enzymology ; Chromatography ; Escherichia coli ; metabolism ; Fatty Acid Synthases ; biosynthesis ; genetics ; Fatty Acids ; biosynthesis ; Plasmids ; Recombinant Proteins ; biosynthesis ; genetics

OBJECTIVETo investigate the expression of fatty acid synthase (FAS) in adenosis, atypical ductal epithelial hyperplasia, ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of breast, and the correlation of FAS expression with HER2 gene amplification in IDC.

METHODSImmunohistochemical EnVision method staining for FAS was performed in 100 cases of breast lesions and 10 normal breast tissues. HER2 gene amplification was detected with FISH in 60 cases of IDC.

RESULTSThe cohort included 10 cases of adenosis, 10 atypical ductal epithelial hyperplasia, 20 DCIS (8 high-grade, 9 intermediated-grade and 3 low-grade), and 60 cases of IDC (5 grade 1, 40 grade 2 and 15 grade 3). FAS expression was negative in all 10 normal breast tissues; in the 10 cases of adenosis, strongly positive FAS expression was detected in one case, positive in 2, weakly positive in 4, and negative in 3; in the 10 cases of atypical ductal epithelial hyperplasia, FAS immunohistochemistry showed that 1 was strongly positive, 4 positive, 4 weakly positive, and 1 negative; in the 20 cases of DCIS, FAS immunostaining showed that 12 were strongly positive, 5 positive, 1 weakly positive, and 2 negative; FAS expression showed a clear increasing trend from normal breast tissue, atypical ductal epithelial hyperplasia to DCIS (χ(2) = 42.02, P < 0.01). Likewise, the increasing trend was also demonstrated from adenosis to DCIS (χ(2) = 34.69, P < 0.01). There was also a positive correlation between FAS expression and extent of lesion among normal breast tissue, adenosis, atypical ductal epithelial hyperplasia and DCIS (χ(2) = 86.02, P < 0.01; r = 0.568, P < 0.01). FAS expression was not correlated with the grade of DCIS (χ(2) = 9.12, P = 0.16). In the five cases of grade 1 IDC, FAS immunostaining showed that 4 cases were strongly positive and 1 positive; in the 40 cases of grade 2 IDC, FAS immunostaining showed that 27 strongly positive, 12 positive, and 1 negative; in the 15 cases of grade 3 IDC, FAS immunostaining showed that 6 were strongly positive, 5 positive, 3 weakly positive, and 1 negative; FAS expression was stronger and more extensive in DCIS, IDC grades 1 and 2 than that in other groups. However, FAS expression was weaker in the IDC grade 3 (χ(2) = 11.26, P = 0.01). The positive expression rate of FAS in IDC was generally higher than that in benign breast lesions (χ(2) = 47.19, P < 0.01). In the 60 cases of IDC, FISH showed HER2 gene amplification in 22 cases, but not in the remaining 38 cases. FAS expression in IDC was highly correlated with HER2 gene amplification (r = 0.44, P < 0.01). The expression of FAS had significant correlation with status of ER and PR and tumor size (P < 0.05). There was no significant correlation with age, immunohistochemical HER2 expression, lymph node metastasis and clinical stage (P > 0.05).

CONCLUSIONSFAS may be closely related to the carcinogenesis of breast IDC. FAS expression is closely associated with HER2 gene amplification in IDC.

Breast ; metabolism ; pathology ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Carcinoma, Ductal, Breast ; genetics ; metabolism ; pathology ; Carcinoma, Intraductal, Noninfiltrating ; genetics ; metabolism ; pathology ; Fatty Acid Synthases ; metabolism ; Female ; Fibrocystic Breast Disease ; metabolism ; Gene Amplification ; Genes, erbB-2 ; Humans ; Hyperplasia ; Lymphatic Metastasis ; Middle Aged ; Receptor, ErbB-2 ; metabolism

OBJECTIVETo explore the effects of zinc-alpha2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HFD)-induced obesity in mice and the possible mechanism.

METHODSThirty-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 determined by reverse transcription-polymerase chain reaction.

RESULTSSerum 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 < 0.001), 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 epididymal 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.

CONCLUSIONSZAG 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.

Adipose Tissue ; metabolism ; Animals ; Fatty Acid Synthases ; genetics ; physiology ; Liver ; enzymology ; Male ; Mice ; Mice, Obese ; Seminal Plasma Proteins ; blood ; physiology ; Sterol Esterase ; genetics ; physiology ; Weight Loss

BACKGROUNDEstrogen deficiency contributes to postmenopausal osteoporosis. Periosteum might be a potential target of estrogen, but the underlying mechanism at gene level is far from being elucidated. The objective of this study was to investigate the correlation between estrogen and fatty acid synthase (FAS) expression in periosteum.

METHODSHuman periosteum cells were cultured in vitro. Expressed genes in the substrated cDNA library were verified using semi-quantitative PCR and real-time PCR. The expression of FAS in periosteum of ovarectomized (OVX) SD rats was investigated.

RESULTSFAS gene was most significantly expressed in the subtracted cDNA library of periosteal cells screened by semi-quantitative PCR. Low FAS expression was verified by real-time PCR in the estrogen exposed human periosteum rather than in the control. The estradiol levels were (20.81 +/- 12.62) pg/ml, (19.64 +/- 4.35) pg/ml and (13.47 +/- 1.84) pg/ml in the sham group, the control, and the OVX group, respectively. The estradiol levels in the OVX group was significantly lower (P = 0.0386). The FAS gene expression in periosteum in the OVX group, sham group, and control group was 3.09 +/- 1.97, 1.33 +/- 0.47 and 1.51 +/- 1.32, respectively. The gene expression in the OVX group was significantly higher (P = 0.0372).

CONCLUSIONEstrogen modulates FAS gene expression in in vitro human perisoteum as well as in in vivo rat periosteum.

Animals ; Cells, Cultured ; Estradiol ; blood ; pharmacology ; physiology ; Fatty Acid Synthases ; genetics ; Female ; Gene Expression Regulation ; drug effects ; Humans ; Ovariectomy ; Periosteum ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo study the role of S6K1 in the induction of SREBP1c in mouse hepatic cell by high glucose stimulation.

METHODSS6K1 shRNA recombinant adenovirus (S6K1Ax) was injected into tail vein of db/db mice and then hepatic triglycerol content was analyzed. Liver specimen were stained with HE. After transfection with S6K1Ax or pU6Ax, mouse hepatic AML12 cells were treated with high glucose, insulin or glucose and insulin, the expression of mSREBP1c was detected by RT-PCR. S6K1 protein was detected by Western blot.

RESULTSHepatic S6K1 protein in db/db mice was inhibited a week after S6K1Ax injection. Compared with the control group, hepatic triglycerol content of S6K1Ax group was decreased (0.65+/-0.02) mmol/L vs (0.56+/-0.01) mmol/L (t = 4.312, P less than 0.01), hepatocyte fat droplet and vaculor generation were also decreased, fatty liver was improved. The mSREBP1c expression in S6K1Ax transfected cells was lower than that in the control cells (0.03+/-0.01 vs 0.06+/-0.01, t = 5.624, P less than 0.01). Compared with the basal state, SREBP1c expression of both groups was increased on the insulin stimulation, S6K1Ax group was 0.06+/-0.02 (t = 8.452, P less than 0.01) and control group was 0.08+/-0.02 (t = 3.591, P less than 0.05). There is no difference between control and S6K1Ax group by glucose addition (P more than 0.05).

CONCLUSIONS6K1 acts on fatty synthesis by regulating mSREBP1c expression.

Adenoviridae ; genetics ; Animals ; Cell Line ; Fatty Acid Synthases ; genetics ; metabolism ; Gene Expression Regulation ; Glucose ; administration & dosage ; Insulin ; administration & dosage ; Liver ; metabolism ; pathology ; Liver Cirrhosis ; etiology ; metabolism ; pathology ; Mice ; Mice, Inbred Strains ; RNA Interference ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Ribosomal Protein S6 Kinases, 90-kDa ; genetics ; metabolism ; Staining and Labeling ; Sterol Regulatory Element Binding Protein 1 ; genetics ; metabolism ; Transfection ; Triglycerides ; metabolism

OBJECTIVETo study the activation of sterol regulatory element binding protein (SREBP) and its critical role in endothelial cell migration.

METHODSBovine aortic endothelial cells (ECs) were cultured. The expression of SREBP and Cdc42 were determined by Western blot and quantitative real-time PCR. Moreover, outward growth migration model and transwell chamber assay were used to detect ECs migration.

RESULTS(1) SREBP was activated during ECs migration. Western blot analysis demonstrated increased active form SREBP in migrating as compared to non-migrating ECs population. SREBP activation decreased as ECs migration slowed;(2) Coincidental with SREBP activation, mRNA expression of its target genes such as low density lipoprotein receptor, HMG-CoA reductase, and fatty acid synthase also increased in migrating ECs population as detected by real-time PCR; (3) Migration induced SREBP activation in ECs was inhibited by SREBP-acting protein RNAi and pharmacologically by 25-hydroxycholesterol; (4) Inhibition of SREBP led to decreased ECs migration in various models; (5) Cells genetically deficient in SREBP-acting protein, S1P, or S2P, phenotypically exhibited impaired migration; (6) SREBP inhibition in ECs suppressed the activity of small GTPase Cdc42, a key molecule for ECs motility.

CONCLUSIONSSREBP is activated during and plays a critical role in ECs migration. Targeting SREBP could become a novel approach in fighting diseases involving abnormal ECs migration.

Animals ; Aorta ; cytology ; CHO Cells ; Cattle ; Cell Movement ; Cells, Cultured ; Cricetinae ; Cricetulus ; Endothelial Cells ; Fatty Acid Synthases ; genetics ; metabolism ; Hydroxycholesterols ; pharmacology ; Hydroxymethylglutaryl CoA Reductases ; genetics ; metabolism ; RNA Interference ; RNA, Messenger ; metabolism ; Receptors, LDL ; genetics ; metabolism ; Sterol Regulatory Element Binding Proteins ; metabolism ; physiology

OBJECTIVETo detect the expression of epidermal fatty acid-binding protein (E-FABP) and fatty acid synthase (FAS) in human breast cancer and identify the potential markers and therapeutic targets for breast cancer.

METHODSFAS and E-FABP expressions were detected in 76 patients with infiltrating ductal breast carcinoma using RT-PCR, immunohistochemistry and Western blotting. The possible associations of the expression of the two proteins with the major clinicopathological factors were analyzed.

RESULTSE-FABP and FAS expression levels were significantly decreased (P<0.05) in grade III as compared with grades I and II infiltrating ductal breast carcinoma. There was a positive correlation between E-FABP and FAS expressions, but their expressions were not correlated to the clinicopathological factors of the patients except for the tumor grades. High E-FABP expression level in grades I and II tumors were associated with an early increased responsiveness to FAS.

CONCLUSIONThe variation of the E-FABP and FAS expressions in the lesions is associated with increase of the risk for breast cancer, and the results of this study provide evidence for developing new molecular markers of high-risk lesions and identifying new the targets for breast cancer therapy.

Adult ; Aged ; Biomarkers, Tumor ; biosynthesis ; genetics ; Blotting, Western ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Carcinoma, Ductal, Breast ; genetics ; metabolism ; pathology ; Fatty Acid Synthases ; biosynthesis ; genetics ; Fatty Acid-Binding Proteins ; biosynthesis ; genetics ; Female ; Humans ; Immunohistochemistry ; Middle Aged ; Reverse Transcriptase Polymerase Chain Reaction