The Escherichia coli fadR protein product, a paradigm/prototypical FadR regulator, positively regulates fabA and fabB, the two critical genes for unsaturated fatty acid (UFA) biosynthesis. However the scenario in the other Ɣ-proteobacteria, such as Shewanella with the marine origin, is unusual in that Rodionov and coworkers predicted that only fabA (not fabB) has a binding site for FadR protein. It raised the possibility of fad regulon contraction. Here we report that this is the case. Sequence alignment of the FadR homologs revealed that the N-terminal DNA-binding domain exhibited remarkable similarity, whereas the ligand-accepting motif at C-terminus is relatively-less conserved. The FadR homologue of S. oneidensis (referred to FadR_she) was over-expressed and purified to homogeneity. Integrative evidence obtained by FPLC (fast protein liquid chromatography) and chemical cross-linking analyses elucidated that FadR_she protein can dimerize in solution, whose identity was determined by MALDI-TOF-MS. In vitro data from electrophoretic mobility shift assays suggested that FadR_she is almost functionally-exchangeable/equivalent to E. coli FadR (FadR_ec) in the ability of binding the E. coli fabA (and fabB) promoters. In an agreement with that of E. coli fabA, S. oneidensis fabA promoter bound both FadR_she and FadR_ec, and was disassociated specifically with the FadR regulatory protein upon the addition of long-chain acyl-CoA thioesters. To monitor in vivo effect exerted by FadR on Shewanella fabA expression, the native promoter of S. oneidensis fabA was fused to a LacZ reporter gene to engineer a chromosome fabA-lacZ transcriptional fusion in E. coli. As anticipated, the removal of fadR gene gave about 2-fold decrement of Shewanella fabA expression by β-gal activity, which is almost identical to the inhibitory level by the addition of oleate. Therefore, we concluded that fabA is contracted to be the only one member of fad regulon in the context of fatty acid synthesis in the marine bacteria Shewanella genus.
Amino Acid Sequence ; Bacterial Proteins ; chemistry ; metabolism ; Base Sequence ; Binding Sites ; DNA, Bacterial ; metabolism ; Escherichia coli ; genetics ; metabolism ; Fatty Acid Synthase, Type II ; genetics ; metabolism ; Fatty Acids ; biosynthesis ; Gene Expression Regulation, Bacterial ; drug effects ; Molecular Sequence Data ; Oleic Acid ; pharmacology ; Protein Binding ; drug effects ; Regulon ; genetics ; Repressor Proteins ; chemistry ; metabolism ; Shewanella ; genetics ; metabolism

OBJECTIVE: To observe the protective effect of heart-fatty acid binding protein (H-FABP) on lipopolysaccharide (LPS)-induced cardiomyocyte damage. METHODS: The cardiomyocytes were isolated and cultured from 1-3 days old neonatal rats. The specific siRNA or plasmid of H-FABP were transfected into cells to alter H-FABP expression, which was evaluated by Western blot and quantitative-PCR. LPS-induced cardiomyocyte damage and inflammation were estimated by detecting the contents of lactate dehydrogenase(LDH), TNF-α, and IL-1β as well as cell viability. RESULTS: LPS treatment induced inflammation and cell damage indicated by a decrease in cell viability and an increase in LDH, TNF-α and IL-1β in the medium. When H-FABP was downregulated by siRNA transfection, the LPS-induced inflammation and cell damage were augmented. In contrast, when H-FABP was overexpressed by pcDNA3.1-H-FABP transfection, the LPS-induced inflammation and cell damage were suppressed. CONCLUSION H-FABP protects cardiomyocytes from LPS-induced inflammation and cell injury.
Animals ; Animals, Newborn ; Cell Line ; Cell Survival ; Down-Regulation ; Fatty Acid Binding Protein 3 ; Fatty Acid-Binding Proteins ; metabolism ; Inflammation ; metabolism ; Interleukin-1beta ; metabolism ; L-Lactate Dehydrogenase ; metabolism ; Lipopolysaccharides ; adverse effects ; Myocytes, Cardiac ; cytology ; drug effects ; RNA, Small Interfering ; genetics ; Rats ; Transfection ; Tumor Necrosis Factor-alpha ; metabolism

Serum palmitic acid (PA), a type of saturated fatty acid, causes lipid accumulation and induces toxicity in hepatocytes. Ethanol (EtOH) is metabolized by the liver and induces hepatic injury and inflammation. Herein, we analyzed the effects of EtOH on PA-induced lipotoxicity in the liver. Our results indicated that EtOH aggravated PA-induced apoptosis and lipid accumulation in primary rat hepatocytes in dose-dependent manner. EtOH intensified PA-caused endoplasmic reticulum (ER) stress response in vitro and in vivo, and the expressions of CHOP, ATF4, and XBP-1 in nucleus were significantly increased. EtOH also increased PA-caused cleaved caspase-3 in cytoplasm. In wild type and CHOP(-/-) mice treated with EtOH and high fat diet (HFD), EtOH worsened the HFD-induced liver injury and dyslipidemia, while CHOP knockout blocked toxic effects of EtOH and PA. Our study suggested that targeting UPR-signaling pathways is a promising, novel approach to reducing EtOH and saturated fatty acid-induced metabolic complications.
Activating Transcription Factor 4 ; drug effects ; metabolism ; Animals ; Apoptosis ; drug effects ; Caspase 3 ; drug effects ; Chemical and Drug Induced Liver Injury ; metabolism ; DNA-Binding Proteins ; drug effects ; metabolism ; Diet, High-Fat ; adverse effects ; Dose-Response Relationship, Drug ; Dyslipidemias ; chemically induced ; metabolism ; Endoplasmic Reticulum Stress ; drug effects ; Ethanol ; metabolism ; toxicity ; Fatty Liver ; chemically induced ; metabolism ; Gene Knockout Techniques ; Hepatocytes ; drug effects ; metabolism ; Lipid Metabolism ; drug effects ; Liver ; metabolism ; Male ; Mice ; Palmitic Acid ; toxicity ; Rats ; Rats, Sprague-Dawley ; Regulatory Factor X Transcription Factors ; Signal Transduction ; drug effects ; Transcription Factor CHOP ; drug effects ; genetics ; metabolism ; Transcription Factors ; drug effects ; metabolism ; Unfolded Protein Response ; drug effects ; X-Box Binding Protein 1

OBJECTIVETo study the expression of fatty acid binding protein 4 (FABP4) in lungs and bronchoalveolar lavage fluid (BALF) of preterm rats exposed to 60% O2 and to elucidate the relationship between the changes of FABP4 expression and the pathogenesis of bronchopulmonary dysplasia (BPD).

METHODSHyperoxic lung injury was induced by exposing to 60% O2 in Spraque-Dawley rats within 6 hours after birth. Rats exposed to air were used as the control group. The lungs from groups aged postnatal days 3, 7 and 14 were removed and dissected from the main bronchi for analysis. Eight rats of each group were used to assess expression of FABP4 in lungs by immunohistochemistry and ELISA. Lung FABP4 mRNA levels were measured by semi-quantitative reverse transcription polymerase chain reaction. The levels of FABP4 in BALF were measured using ELISA.

RESULTSFABP4 immunoreactivity was detected in the majority of alveolar macrophages, bronchial epithelial cells and endothelial cells. FABP4 protein levels in lung tissues in the hyperoxic exposure group increased significantly compared with the control group on days 3, 7 and 14 after birth (P<0.05), and FABP4 mRNA levels in lung tissues also increased significantly in the hyperoxic exposure group compared with the control group on days 7 and 14 after birth (P<0.05). The hyperoxic exposure group demonstrated increased FABP4 levels in BALF compared with the control group on days 7 and 14 after birth (P<0.05).

CONCLUSIONSFABP4 levels increase in preterm rat lungs after hyperoxic lung injury, which may contribute to the pathogenesis of BPD.

Animals ; Bronchopulmonary Dysplasia ; etiology ; Fatty Acid-Binding Proteins ; analysis ; genetics ; Female ; Hyperoxia ; metabolism ; Lung ; chemistry ; Lung Injury ; metabolism ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor A ; physiology

Escherichia coli (E. coli) FadR regulator plays dual roles in fatty acid metabolism, which not only represses the fatty acid degradation (fad) system, but also activates the unsaturated fatty acid synthesis pathway. Earlier structural and biochemical studies of FadR protein have provided insights into interplay between FadR protein with its DNA target and/or ligand, while the missing knowledge gap (esp. residues with indirect roles in DNA binding) remains unclear. Here we report this case through deep mapping of old E. coli fadR mutants accumulated. Molecular dissection of E. coli K113 strain, a fadR mutant that can grow on decanoic acid (C10) as sole carbon sources unexpectedly revealed a single point mutation of T178G in fadR locus (W60G in FadRk113). We also observed that a single genetically-recessive mutation of W60G in FadR regulatory protein can lead to loss of its DNA-binding activity, and thereby impair all the regulatory roles in fatty acid metabolisms. Structural analyses of FadR protein indicated that the hydrophobic interaction amongst the three amino acids (W60, F74 and W75) is critical for its DNA-binding ability by maintaining the configuration of its neighboring two β-sheets. Further site-directed mutagenesis analyses demonstrated that the FadR mutants (F74G and/or W75G) do not exhibit the detected DNA-binding activity, validating above structural reasoning.
3-Oxoacyl-(Acyl-Carrier-Protein) Synthase ; genetics ; metabolism ; Amino Acid Sequence ; Bacterial Proteins ; chemistry ; genetics ; metabolism ; DNA, Bacterial ; chemistry ; metabolism ; Escherichia coli ; genetics ; metabolism ; Escherichia coli Proteins ; genetics ; metabolism ; Fatty Acid Synthase, Type II ; genetics ; metabolism ; Fatty Acids ; metabolism ; Gene Expression Regulation, Bacterial ; Hydro-Lyases ; genetics ; metabolism ; Hydrophobic and Hydrophilic Interactions ; Lipid Metabolism ; Models, Molecular ; Molecular Sequence Data ; Mutation ; Protein Binding ; Protein Structure, Secondary ; Repressor Proteins ; chemistry ; genetics ; metabolism ; Sequence Alignment ; Sequence Homology, Amino Acid ; Signal Transduction

Cervical cancer is the second most common gynecological cancer among Korean women. While nationwide screening program has developed, the pathogenesis of cervical cancer is unknown. The aim of this study was to compare the protein expression profiles between cervical squamous carcinomas and normal cervical tissues in order to identify proteins that are related to the cancer. Three cervical cancer tissue samples and three normal cervical tissue samples were obtained and protein expression was compared and was identified in the samples with the use of matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). A total of 20 proteins that showed up-regulated expression in the cervical cancer tissue samples were selected and identified. Seven proteins were matched to allograft inflammatory factor 1 (AIF-1), actine-like protein 2 (ALP2), brain type fatty acid-binding protein (B-FABP), NCK adaptor protein 1 (NCK-1), islet cell autoantigen 1 (ICA69), cationic trypsinogen (PRSS1), and cyclin-dependent kinase 4 (CDK4), but the remaining 13 proteins were unidentifiable. After confirmation by RT-PCR, Western blotting and immunohistochemistry, we found that B-FABP, NCK-1, and CDK4 were related to the pathogenesis of cervical cancer. These proteins are suggested as candidates of new pathological tumor markers for cervical cancer.
Adaptor Proteins, Signal Transducing/genetics/metabolism ; Blotting, Western ; Carcinoma, Squamous Cell/*metabolism/pathology ; Cyclin-Dependent Kinase 4/genetics/metabolism ; Electrophoresis, Gel, Two-Dimensional ; Fatty Acid-Binding Proteins/genetics/metabolism ; Female ; Humans ; Immunohistochemistry ; Oncogene Proteins/genetics/metabolism ; *Proteomics ; Reverse Transcriptase Polymerase Chain Reaction ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Tumor Markers, Biological/genetics/*metabolism ; Uterine Cervical Neoplasms/*metabolism/pathology

BACKGROUND/AIMS: Adipose tissue is an active endocrine organ that secretes various metabolically important substances including adipokines, which represent a link between insulin resistance and nonalcoholic steatohepatitis (NASH). The factors responsible for the progression from simple steatosis to steatohepatitis remain elusive, but adipokine imbalance may play a pivotal role. We evaluated the expressions of adipokines such as visfatin, adipocyte-fatty-acid-binding protein (A-FABP), and retinol-binding protein-4 (RBP-4) in serum and tissue. The aim was to discover whether these adipokines are potential predictors of NASH. METHODS: Polymerase chain reaction, quantification of mRNA, and Western blots encoding A-FABP, RBP-4, and visfatin were used to study tissue samples from the liver, and visceral and subcutaneous adipose tissue. The tissue samples were from biopsy specimens obtained from patients with proven NASH who were undergoing laparoscopic cholecystectomy due to gallbladder polyps. RESULTS: Patients were classified into two groups: NASH, n=10 and non-NASH, n=20 according to their nonalcoholic fatty liver disease Activity Score. Although serum A-FABP levels did not differ between the two groups, the expressions of A-FABP mRNA and protein in the visceral adipose tissue were significantly higher in NASH group than in non-NASH group (104.34 vs. 97.05, P<0.05, and 190.01 vs. 95.15, P<0.01, respectively). Furthermore, the A-FABP protein expression ratio between visceral adipose tissue and liver was higher in NASH group than in non-NASH group (4.38 vs. 1.64, P<0.05). CONCLUSIONS: NASH patients had higher levels of A-FABP expression in their visceral fat compared to non-NASH patients. This differential A-FABP expression may predispose patients to the progressive form of NASH.
Adipose Tissue/metabolism/pathology ; Adult ; Aged ; Fatty Acid-Binding Proteins/genetics/*metabolism ; Fatty Liver/metabolism/*pathology ; *Gene Expression Regulation ; Humans ; Intra-Abdominal Fat/*metabolism ; Liver/metabolism/pathology ; Middle Aged ; Nicotinamide Phosphoribosyltransferase/genetics/metabolism ; RNA, Messenger/metabolism ; Retinol-Binding Proteins, Plasma/genetics/metabolism

AIMTo explore the changes of mRNA and protein expressions of heart-type fatty acid binding protein (H-FABP) in rat ischemic myocardium at different intervals ischemia.

METHODS60 SD male rats weighing 250-350 g, were randomly divided into one sham-operated group and five study groups (group A1, A2, A3, A4, A5, the left coronary artery of rats has been ligated for 1 h, 2 h, 4 h, 6 h, 12 h respectively). Myocardil samples from infarct zone, ischemic and non-ischemic zone, were obtained for histology examination, and the mRNA for H-FABP in ischemic myocardial tissue were determined by RT-PCR. Serum free fatty acid(FFA) was determined by colorimetric method.

RESULTSCompared to sham hearts, H-FABP mRNA expression were significantly decreased in ischemia zone of AMI rat hearts (P < 0.05), especially in rats underwent 4 h ischemia and 6 h ischemia (P < 0.01). Serum FFA were significantly increased in AMI rats relative to sham rats (P < 0.05).

CONCLUSIONSignificant down-regulated heart-type fatty acid binding protein after myocardial ischemia might play an important role in myocardial injury and energy metabolism disorder.

Animals ; Down-Regulation ; Fatty Acid-Binding Proteins ; genetics ; metabolism ; Male ; Myocardial Infarction ; metabolism ; Myocytes, Cardiac ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley

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