SCD1 Gene Research Articles

Nutritional modification of <i>SCD</i>, <i>ACACA</i> and <i>LPL</i> gene expressions in different ovine tissues

Abstract. Fatty acid composition is one of the main factors affecting health benefits of food. Stearoyl-CoA desaturase 1 (SCD), acetyl-CoA carboxylase alpha (ACACA) and lipoprotein lipase (LPL) have been considered as the rate-limiting enzymes in the biosynthesis of different fatty acids critical in lipid metabolism. The aim of our study was the analysis of differences in expression profiles of three ovine genes related to lipid metabolism (LPL, ACACA, SCD) depending on feeding system and tissue type. The gene expression measurement was performed using a real-time PCR method on 60 old-type Polish Merino Sheep, which were divided into three feeding groups (I – complete pellet mixture, n = 12; II – complete mixture with addition of fresh grass, n = 24; III – complete mixture with addition of fresh red clover, n = 24). From all lambs, tissue samples – subcutaneous fat, perirenal fat and liver – were collected immediately after slaughter and LPL, ACACA and SCD expression was estimated based on two endogenous controls (RPS2 – ribosomal protein S2; ATP5G2 – H(+)-transporting ATP synthase). Our research indicated that supplementation of diet with an addition of fresh grass or red clover significantly (P < 0.05) decreased the expression of SCD, ACACA and LPL genes in fat tissue compared to standard complete pelleted mixture. On the other hand, the highest expression of ACACA was detected in liver tissue collected from sheep fed a diet with an addition of fresh red clover (P < 0.05). In turn, the highest expression of the SCD gene was detected in animals fed with grass supplementation (P < 0.05). Regardless of diet supplementation, the highest SCD transcript abundance was detected in perirenal fat, while LPL and ACACA expression was the highest in both perirenal and subcutaneous fat. The ability of nutrigenomic regulation of transcription of analyzed genes confirmed that these genes play a critical role in regulation of lipid metabolism processes in sheep and could be associated with fatty acid profiles in milk and meat.

Abstract 4317: EGLN1/c-Myc induced lymphoid-specific helicase inhibits ferroptosis through lipid metabolic gene expression changes

Abstract Ferroptosis has emerged as a new form of non-apoptotic cell death in multiple human diseases. However, the epigenetic mechanisms of ferroptosis remain poorly defined. We demonstrate that Lymphoid-specific helicase (LSH), a DNA methylation modifier, interacts with WDR76 to inhibit ferroptosis by activating lipid metabolism-associated genes, including GLUT1, and ferroptosis related genes SCD1 and FADS2. These effects are dependent on iron and lipid reactive oxygen species. We further show that EGLN1 and c-Myc directly activate LSH expression by inhibiting HIF-1α. Finally, we demonstrate that LSH functions as an oncogene in lung cancer in vitro and in vivo. Therefore, our study elucidates the molecular basis for a c-Myc/EGLN1-mediated induction of LSH expression to inhibit ferroptosis, which can be exploited for the development of therapeutic agents to target ferroptosis in cancer. Note: This abstract was not presented at the meeting. Citation Format: Yongguang Tao, Shuang Liu, Yiqun Jiang. EGLN1/c-Myc induced lymphoid-specific helicase inhibits ferroptosis through lipid metabolic gene expression changes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4317. doi:10.1158/1538-7445.AM2017-4317

Subspecies and diet affect the expression of genes involved in lipid metabolism and chemical composition of muscle in beef cattle

Fourteen Nellore and 14 Angus young bulls with BW of 381±11.8kg were randomly assigned into 2 feeding groups (whole shelled corn without forage (WSC) or corn silage and ground corn (GC)) to evaluate chemical composition and expression of genes involved in lipid metabolism in the longissimus thoracis (LT). We hypothesized that bulls fed the WSC diet have greater amounts of intramuscular fat and Angus have higher expression levels of PPAR and SREBF. Meat from Angus bulls had greater ether extract compared to Nellore (P<0.05). Muscle from bulls fed the WSC diet had greater expression of PPARA (P<0.05) and lower levels of SREBF1 expression (P<0.01). The LT of Nellore fed GC had greater expression of FABP4, ACACA and SCD genes (P<0.01). In conclusion, the greater concentration of starch in the WSC diet did not increase marbling in the beef of bulls fed this diet due to the reduced expression of SREBF1.

A High-Fructose-High-Coconut Oil Diet Induces Dysregulating Expressions of Hippocampal Leptin and Stearoyl-CoA Desaturase, and Spatial Memory Deficits in Rats.

We investigated the effects of high-fructose-high-fat diets with different fat compositions on metabolic parameters, hippocampal-dependent cognitive function, and brain leptin (as well as stearoyl-CoA desaturase (SCD1) mRNA expressions). Thirty-two male Wistar rats were divided into 3 groups, a control group (n = 8), a high-fructose soybean oil group (37.5% of fat calories, n = 12), and a high-fructose coconut oil group (37.5% of fat calories, n = 12) for 20 weeks. By the end of the study, the coconut oil group exhibited significantly higher serum fasting glucose, fructosamine, insulin, leptin, and triglyceride levels compared to those of the control and soybean oil groups. However, hippocampal leptin expression and leptin receptor mRNA levels were significantly lower, while SCD1 mRNA was significantly higher in rats fed the high-fructose-high-coconut oil diet than in rats fed the other experimental diets. In addition, the coconut oil group spent significantly less time in the target quadrant on the probe test in the Morris water maze (MWM) task. Rats fed the high-fructose-high-coconut oil diet for 20 weeks were prone to develop hyperglycemia, hyperinsulinemia, hyperleptinemia, and hypertriglyceridemia. These metabolic consequences may contribute to hippocampal-dependent memory impairment, accompanied by a lower central leptin level, and a higher SCD1 gene expression in the brain.

Genome-wide association study confirm major QTL for backfat fatty acid composition on SSC14 in Duroc pigs

BackgroundFatty acid composition contributes importantly to meat quality and is essential to the nutritional value of the meat. Identification of genetic factors underlying levels of fatty acids can be used to breed for pigs with healthier meat. The aim of this study was to conduct genome-wide association studies (GWAS) to identify QTL regions affecting fatty acid composition in backfat from the pig breeds Duroc and Landrace.ResultsUsing data from the Axiom porcine 660 K array, we performed GWAS on 454 Duroc and 659 Landrace boars for fatty acid phenotypes measured by near-infrared spectroscopy (NIRS) technology (C16:0, C16:1n-7, C18:0, C18:1n-9, C18:2n-6, C18:3n-3, total saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids). Two QTL regions on SSC4 and SSC14 were identified in Duroc for the de novo synthesized fatty acids traits, whereas one QTL on SSC8 was detected in Landrace for C16:1n-7. The QTL region on SSC14 has been reported in previous studies and a putative causative mutation has been suggested in the promoter region of the SCD gene. Whole genome re-sequencing data was used for genotype imputation and to fine map the SSC14 QTL region in Norwegian Duroc. This effort confirms the location of the QTL on this chromosome as well as suggesting other putative candidate genes in the region. The most significant single nucleotide polymorphisms (SNPs) located on SSC14 explain between 55 and 76% of the genetic variance and between 27 and 54% of the phenotypic variance for the de novo synthesized fatty acid traits in Norwegian Duroc. For the QTL region on SSC8 in Landrace, the most significant SNP explained 19% of the genetic variance and 5% of the phenotypic variance for C16:1n-7.ConclusionsThis study confirms a major QTL affecting fatty acid composition on SSC14 in Duroc, which can be used in genetic selection to increase the level of fatty acid desaturation. The SSC14 QTL was not segregating in the Landrace population, but another QTL on SSC8 affecting C16:1n-7 was identified and might be used to increase the level of desaturation in meat products from this breed.

Altered fatty acid metabolism and reduced stearoyl-coenzyme a desaturase activity in asthma.

Fatty acids and lipid mediator signaling play an important role in the pathogenesis of asthma, yet this area remains largely underexplored. The aims of this study were (i) to examine fatty acid levels and their metabolism in obese and nonobese asthma patients and (ii) to determine the functional effects of altered fatty acid metabolism in experimental models. Medium- and long-chain fatty acid levels were quantified in serum from 161 human volunteers by LC/MS. Changes in stearoyl-coenzyme A desaturase (SCD) expression and activity were evaluated in the ovalbumin (OVA) and house dust mite (HDM) murine models. Primary human bronchial epithelial cells from asthma patients and controls were evaluated for SCD expression and activity. The serum desaturation index (an indirect measure of SCD) was significantly reduced in nonobese asthma patients and in the OVA murine model. SCD1 gene expression was significantly reduced within the lungs following OVA or HDM challenge. Inhibition of SCD in mice promoted airway hyper-responsiveness. SCD1 expression was suppressed in bronchial epithelial cells from asthma patients. IL-4 and IL-13 reduced epithelial cell SCD1 expression. Inhibition of SCD reduced surfactant protein C expression and suppressed rhinovirus-induced IP-10 secretion, which was associated with increased viral titers. This is the first study to demonstrate decreased fatty acid desaturase activity in humans with asthma. Experimental models in mice and human epithelial cells suggest that inhibition of desaturase activity leads to airway hyper-responsiveness and reduced antiviral defense. SCD may represent a new target for therapeutic intervention in asthma patients.

Maternal high-fat diet during pregnancy and lactation affects hepatic lipid metabolism in early life of offspring rat.

We investigated whether maternal over-nutrition during pregnancy and lactation affects the offspring's lipid metabolism at weaning by assessing liver lipid metabolic gene expressions and analysing its mechanisms on the development of metabolic abnormalities. Female Sprague-Dawley rats were fed with standard chow diet (CON) or high-fat diet (HFD) for 8 weeks, and then continued feeding during gestation and lactation. The offspring whose dams were fed with HFD had a lower birth weight but an increased body weight with impaired glucose tolerance, higher serum cholesterol, and hepatic steatosis at weaning. Microarray analyses showed that there were 120 genes differently expressed between the two groups. We further verified the results by qRT-PCR. Significant increase of the lipogenesis (Me1, Scd1) gene expression was found in HFD (P less than 0.05), and up-regulated expression of genes (PPAR-alpha, Cpt1 alpha, Ehhadh) involved in beta-oxidation was also observed (P less than 0.05), but the Acsl3 gene was down-regulated (P less than 0.05). Maternal over-nutrition could not only primarily induce lipogenesis, but also promote lipolysis through an oxidation pathway as compensation, eventually leading to an increased body weight, impaired glucose tolerance, elevated serum cholesterol and hepatic steatosis at weaning. This finding may provide some evidence for a healthy maternal diet in order to reduce the risk of metabolic diseases in the early life of the offspring.

Interactions of bovine oocytes with follicular elements with respect to lipid metabolism.

Among many factors, lipid metabolism within the follicular environment emerges as an important indicator of oocyte quality. In the literature a crucial significance is described concerning follicular fluid (FF) composition as well as messenger RNA (mRNA) expression in follicular cells. The aim of this study was to describe the relationship between oocyte, FF and follicular cells with regard to lipid metabolism. The set of data originating from individual follicles comprised: lipid droplets (LD) number in oocytes (BODIPY staining), mRNA expression of seven genes in cumulus and granulosa cells (SCD, FADS2, ELOVL2, ELOVL5, GLUT1, GLUT3, GLUT8; real time polymerase chain reaction) and fatty acid (FA) composition in FF (gas chromatography). Obtained results demonstrate significant correlation between oocyte lipid droplets number and FA composition in FF. However, gene expression studies show significant correlation between LD number and GLUT1 gene only. Moreover, the present experiment revealed correlations between FA content in FF and expression of several genes (SCD, FADS2, ELOVL5, GLUT8) in granulosa cells, whereas only the SCD gene in cumulus cells. We suggest that the results of our experiment indicate the importance of glucose:lipid metabolism balance, which contributes to better understanding of energy metabolism conversion between oocytes and the maternal environment.

Polymorphism of stearoyl-CoA desaturase (SCD1) gene in Indonesian local cattle

Stearoyl-Coa desaturase (SCD1) gene is one of genes that involves in converting saturated fatty acids to unsaturated fatty acids. SNP at exon 5 in SCD1 gene that changes amino acid valine to alanine (V293A) has an influence to meat fatty acid composition. The aim of this research was to analyze SCD1 gene polymorphisms based on SNP V293A at exon 5 of three Indonesian local cattle. The identification of SCD1 gene polymorphisms was done by using 98, 20 and 7 DNA sample from Ciamis, Bali/Banteng, and Ongole Grade (PO) cattle, respectively. PCR_RFLP method with AciI enzim was carried out to identify SNP Val293Ala. Allelic frequencies and heterozygosity value were analyzed by using POPGENE32. The result showed that SCD1 gene at Ciamis local cattle and PO cattle were polymorphic. Their frequencies were 74.5% and 71.4% for T and 25.5% and 28.6% for C, respectively. There were three genotypes on Ciamis local cattle i.e TT, CT and CC with their frequencies were 52%, 44.9% and 3.10%, respectively. There were two genotypes on PO cattle i.e TT and CT with their frequencies were 42.9% and 57.1%, respectively. Meanwhile, SCD1 gene in Bali cattle was monomorphic. Heterozygosity value of SCD1 gene in Ciamis and PO cattle were 0.38 and 0.44, respectively. Their heterozigosities were categorized as medium.

Loss of ULK1 increases RPS6KB1-NCOR1 repression of NR1H/LXR-mediated Scd1 transcription and augments lipotoxicity in hepatic cells

ABSTRACTLipotoxicity caused by saturated fatty acids (SFAs) induces tissue damage and inflammation in metabolic disorders. SCD1 (stearoyl-coenzyme A desaturase 1) converts SFAs to mono-unsaturated fatty acids (MUFAs) that are incorporated into triglycerides and stored in lipid droplets. SCD1 thus helps protect hepatocytes from lipotoxicity and its reduced expression is associated with increased lipotoxic injury in cultured hepatic cells and mouse models. To further understand the role of SCD1 in lipotoxicity, we examined the regulation of Scd1 in hepatic cells treated with palmitate, and found that NR1H/LXR (nuclear receptor subfamily 1 group H) ligand, GW3965, induced Scd1 expression and lipid droplet formation to improve cell survival. Surprisingly, ULK1/ATG1 (unc-51 like kinase) played a critical role in protecting hepatic cells from SFA-induced lipotoxicity via a novel mechanism that did not involve macroautophagy/autophagy. Specific loss of Ulk1 blocked the induction of Scd1 gene transcription by GW3965, decreased lipid droplet formation, and increased apoptosis in hepatic cells exposed to palmitate. Knockdown of ULK1 increased RPS6KB1 (ribosomal protein S6 kinase, polypeptide 1) signaling that, in turn, induced NCOR1 (nuclear receptor co-repressor 1) nuclear uptake, interaction with NR1H/LXR, and recruitment to the Scd1 promoter. These events abrogated the stimulation of Scd1 gene expression by GW3965, and increased lipotoxicity in hepatic cells. In summary, we have identified a novel autophagy-independent role of ULK1 that regulates NR1H/LXR signaling, Scd1 expression, and intracellular lipid homeostasis in hepatic cells exposed to a lipotoxic environment.

EGLN1/c-Myc Induced Lymphoid-Specific Helicase Inhibits Ferroptosis through Lipid Metabolic Gene Expression Changes.

Ferroptosis is a newly discovered form of non-apoptotic cell death in multiple human diseases. However, the epigenetic mechanisms underlying ferroptosis remain poorly defined. First, we demonstrated that lymphoid-specific helicase (LSH), which is a DNA methylation modifier, interacted with WDR76 to inhibit ferroptosis by activating lipid metabolism-associated genes, including GLUT1, and ferroptosis related genes SCD1 and FADS2, in turn, involved in the Warburg effect. WDR76 targeted these genes expression in dependent manner of LSH and chromatin modification in DNA methylation and histone modification. These effects were dependent on iron and lipid reactive oxygen species. We further demonstrated that EGLN1 and c-Myc directly activated the expression of LSH by inhibiting HIF-1α. Finally, we demonstrated that LSH functioned as an oncogene in lung cancer in vitro and in vivo. Therefore, our study elucidates the molecular basis of the c-Myc/EGLN1-mediated induction of LSH expression that inhibits ferroptosis, which can be exploited for the development of therapeutic strategies targeting ferroptosis for the treatment of cancer.

Prolactin regulatory element-binding protein is involved in suppression of the adiponectin gene in vivo.

Prolactin regulatory element-binding protein (PREB), a member of the WD-repeat protein family, has been recognized as a transcriptional factor that regulates prolactin promoter activity in the anterior pituitary of rats. PREB is expressed not only in the pituitary but also in various other tissues, including the adipose tissue. Previous studies have shown that PREB acts as a transcriptional regulator and suppresses the expression of the adiponectin gene in cultured 3T3L1 preadipocytes. The aim of this study was to further examine the potential role of PREB in adipose tissue in vivo. Transgenic mice that overexpressing PREB (PREB transgenic mice) were generated. Insulin resistance was evaluated in PREB transgenic mice using glucose and insulin tolerance tests. Adiponectin expression in the adipose tissue was examined by western blot analysis and quantitative polymerase chain reaction (qPCR). The expression levels of stearoyl-CoA desaturase (Scd) and adiponectin receptor 2(ADIPOR2) were quantified by qPCR. Glucose and insulin tolerance tests revealed insulin resistance in PREB transgenic mice. Serum adiponectin and leptin concentrations were decreased. Adiponectin gene expression was decreased in the adipose tissue, which was confirmed by the downregulation of the adiponectin-dependent hepatic Scd gene and upregulation of the ADIPOR2 gene in the liver of PREB transgenic mice. We also found that pioglitazone, an agonist for the peroxisome proliferator-activated receptor-r, improved the insulin resistance in the PREB transgenic mice after a 10-day feeding period. These results demonstrated that PREB might contribute to the regulation of adiponectin gene expression in vivo.

153 SUPPLEMENTATION WITH LINOLENIC ACID AND L-CARNITINE DURING IVM REDUCED THE EXPRESSION OF GENES RELATED TO LIPOGENESIS BUT DID NOT ALTER THE LIPID CONTENT AND CRYOTOLERANCE OF IN VITRO-PRODUCED EMBRYOS

This study was conducted to evaluate the impact of supplementation during in vitro maturation (IVM) with linolenic acid (ALA), l-carnitine (L-car), or the combination of both supplements on the embryo intracellular lipid content and cryotolerance, as well as in the embryo expression of genes involved in lipid metabolism (lipogenesis regulation: SCD1, FASN, and SREBP1; and β-oxidation pathway: CPT1B and CPT2). Cumulus-oocyte complexes (n = 1076) were IVM for 22 h at 38.5°C and 5% CO2 in air, in TCM-199 medium with bicarbonate, hormones, and 10% FCS (control group), supplemented with 100 μM ALA (ALA group), 5 mM L-car (L-car group), or a combination of 100 μM ALA + 5 mM L-car (ALA + L-car group). After IVF, presumptive zygotes were in vitro cultured in SOFaa medium supplemented with 5 mg mL−1 BSA and 2.5% FCS, at 38.5°C and 5% CO2 in air during 7 days. Cleavage and blastocyst rates were evaluated on Day 3 and 7, respectively (IVF = Day 0). At Day 7, the blastocysts were stained with the lipophilic dye Sudan Black B (n = 60), vitrified/warmed (n = 260; Ingámed® protocol, Maringa-PR, Brazil), or collected for analysis of gene expression (n = 180). Embryonic development were analysed by ANOVA and the multiple comparisons of means were determined by Tukey’s test. The embryonic re-expansion data were subjected to chi-square test and the differences in gene expression among groups were evaluated by Duncan’s multiple range test (P &lt; 0.05). Data are presented as means ± standard error means. There was no effect (P &gt; 0.05) of the supplements used during IVM on cleavage (79.54 ± 2.76% to 82.16 ± 1.13%) and blastocyst rates (29.03 ± 3.07% to 30.46 ± 2.01%). Similarly, the intracellular lipid content in Day-7 blastocysts (1.03 ± 0.04 to 1.15 ± 0.07 pixels) and the embryonic cryotolerance, assessed by the re-expansion rates after 24 h (67.3 to 78.3%) hatching rates after 48 h (11.5 to 25.5%) of post-warming culture, were unaffected (P &gt; 0.05) by the supplements of IVM medium. Although the treatments did not alter (P &gt; 0.05) the expression of CPT1B and CPT2 genes, the expression of FASN gene was decreased (P &lt; 0.05) in the ALA group and the expression of SREBP1 gene was decreased (P &lt; 0.05) in the ALA and L-car groups. The expression of the gene SCD1 was reduced (P &lt; 0.05) in all treatments compared with the control group. Thus, despite the lack of effects of the treatments performed during IVM on the intracellular lipid content and cryotolerance of the embryos derived from the treated oocytes, a reduction in the expression of genes related to lipogenesis was observed in Day-7 blastocysts. These results suggest that treatments performed in the oocytes during IVM may have prolonged effects, affecting the subsequent expression of genes in embryos. Further studies are needed to determine the mechanisms related to the differentiation of the oocyte machinery during maturation. Financial support was provided by FAPESP (#2012/10084–4 and #2013/07382–6).

FIAT Deletion Increases Bone Mass But Does Not Prevent High-Fat-Diet-Induced Metabolic Complications.

Factor inhibiting activating transcription factor 4 (ATF4)-mediated transcription (FIAT) interacts with ATF4 to repress its transcriptional activity. We performed a phenotypic analysis of Fiat-deficient male mice (Fiat−/Y) at 8 and 16 weeks of age. Microcomputed tomography analysis of the distal femur demonstrated 46% and 13% age-dependent increases in trabecular bone volume and thickness, respectively, in Fiat−/Y mice. Cortical bone measurements at the femoral midshaft revealed a substantial increase in cortical thickness in older Fiat−/Y mice. Bone gain was related to increased mineral apposition rate and increased osteoblast function. Femoral stiffness and strength were substantially increased in Fiat−/Y compared with wild-type (WT) mice. We also investigated whether FIAT contributes to metabolic function. When fed standard mouse chow, Fiat−/Y animals were glucose-tolerant. However, when fed a high-fat diet (HFD) for 8 weeks, Fiat−/Y mice gained more weight than control mice, with a specific increase in white adipose tissue fat mass. The increase in fat mass was due to reduced energy expenditure, which correlated with reduced fatty acid oxidation and lipolysis in the adipose tissue of mutant mice. The expression of the Scd1 gene, involved in lipogenesis, was upregulated in the subcutaneous adipose tissue of Fiat−/Y mice. Moreover, HFD-fed Fiat−/Y mice exhibited increased circulating leptin and insulin levels relative to WT mice, demonstrating that endocrine abnormalities are associated with the disturbance in energy balance. We conclude that Fiat−/Y mice exhibited an anabolic bone phenotype but displayed increased susceptibility to developing metabolic-related disorders when consuming an HFD.

0342 Expression levels of the bovine SCD gene are significantly associated with fatty acid composition of cattle

0342 Expression levels of the bovine SCD gene are significantly associated with fatty acid composition of cattle

Symplocos cochinchinensis enhances insulin sensitivity via the down regulation of lipogenesis and insulin resistance in high energy diet rat model

Ethnopharmacological relevanceThis plant has been utilized in Indian system of medicine for treatment of diabetes. This is clearly evident from the composition of Ayurvedic preparation for diabetes ‘Nisakathakadi Kashayam’ where this is one of the main ingredients of this preparation Aim of the studyThe study aims in elucidating the molecular mechanisms underlying the insulin sensitizing effects of Symplocos cochinchinensis ethanol extract (SCE) using a high fructose and saturated fat (HFS) fed insulin resistant rat model. Materials and methodsExperimental groups consisted of normal diet (ND), ND+SCE 500mg/kg bwd, HFS+vehicle, HFS+metformin 100mg/kg bwd, HFS+SCE 250/500mg/kg bwd. Initially the animals were kept under HFS diet for 8 weeks, and at the end of 8 week period, animals were found to develop insulin resistance and dyslipidemia. Post-administration of SCE, metformin or vehicle were carried out for 3 weeks. Gene and protein expressions relevant to insulin signalling pathway were analysed. ResultsHFS significantly altered the normal physiology of animals via proteins and genes relevant to metabolism like stearoyl-CoA desaturase (SCD1), sterol regulatory element binding protein 1 (SREBP-1c), fatty acid synthase (FAS), glucose 6 phosphatase (G6Pase), phosphoenol pyruvate carboxykinase (PEPCK), glucose transporter 2 (GLUT2), protein tyrosine phosphatse 1B (PTP1B), peroxisome proliferator activated receptor alpha (PPAR alpha), sirtuin 1 (SIRT1) and glucokinase. SCE administration attenuates the insulin resistance in HFS rat by the down regulation of SCD1 gene expression that modulates SREBP-1c dependent and independent hepatic lipid accumulation. ConclusionSCE enhances insulin sensitivity via the down regulation of lipogenesis and insulin resistance in HFS rat model.

PtrA Is Functionally Intertwined with GacS in Regulating the Biocontrol Activity of Pseudomonas chlororaphis PA23.

In vitro inhibition of the fungal pathogen Sclerotinia sclerotiorum by Pseudomonas chlororaphis PA23 is reliant upon a LysR-type transcriptional regulator (LTTR) called PtrA. In the current study, we show that Sclerotinia stem rot and leaf infection are significantly increased in canola plants inoculated with the ptrA-mutant compared to the wild type, establishing PtrA as an essential regulator of PA23 biocontrol. LTTRs typically regulate targets that are upstream of and divergently transcribed from the LTTR locus. We identified a short chain dehydrogenase (scd) gene immediately upstream of ptrA. Characterization of a scd mutant revealed that it is phenotypically identical to the wild type. Moreover, scd transcript abundance was unchanged in the ptrA mutant. These findings indicate that PtrA regulation does not involve scd, rather this LTTR controls genes located elsewhere on the chromosome. Employing a combination of complementation and transcriptional analysis we investigated whether connections exist between PtrA and other regulators of biocontrol. Besides ptrA, gacS was the only gene able to partially rescue the wild-type phenotype, establishing a connection between PtrA and the sensor kinase GacS. Transcriptomic analysis revealed decreased expression of biosynthetic (phzA, prnA) and regulatory genes (phzI, phzR, rpoS, gacA, rsmX, rsmZ, retS) in the ptrA mutant; conversely, rsmE, and rsmY were markedly upregulated. The transcript abundance of ptrA was nine-fold higher in the mutant background indicating that this LTTR negatively autoregulates itself. In summary, PtrA is an essential regulator of genes required for PA23 biocontrol that is functionally intertwined with GacS.

Characterization of Stearoyl-CoA Desaturases from a Psychrophilic Antarctic Copepod, Tigriopus kingsejongensis.

Stearoyl-CoA desaturase is a key regulator in fatty acid metabolism that catalyzes the desaturation of stearic acid to oleic acid and controls the intracellular levels of monounsaturated fatty acids (MUFAs). Two stearoyl-CoA desaturases (SCD, Δ9 desaturases) genes were identified in an Antarctic copepod, Tigriopus kingsejongensis, that was collected in a tidal pool near the King Sejong Station, King George Island, Antarctica. Full-length complementary DNA (cDNA) sequences of two T. kingsejongensis SCDs (TkSCDs) were obtained from next-generation sequencing and isolated by reverse transcription PCR. DNA sequence lengths of the open reading frames of TkSCD-1 and TkSCD-2 were determined to be 1110 and 681bp, respectively. The molecular weights deduced from the corresponding genes were estimated to be 43.1kDa (TkSCD-1) and 26.1kDa (TkSCD-2). The amino acid sequences were compared with those of fatty acid desaturases and sterol desaturases from various organisms and used to analyze the relationships among TkSCDs. As assessed by heterologous expression of recombinant proteins in Escherichia coli, the enzymatic functions of both stearoyl-CoA desaturases revealed that the amount of C16:1 and C18:1 fatty acids increased by greater than 3-fold after induction with isopropyl β-D-thiogalactopyranoside. In particular, C18:1 fatty acid production increased greater than 10-fold in E. coli expressing TkSCD-1 and TkSCD-2. The results of this study suggest that both SCD genes from an Antarctic marine copepod encode a functional desaturase that is capable of increasing the amounts of palmitoleic acid and oleic acid in a prokaryotic expression system.

Favorable Hepatoprotective Effects of Gongjin-dan on the Acute Ethanol-induced Liver Damaged C57BL/6 M ice

To observe the potential hepatoprotective effects of Gongjin-dan on the acute ethanol (EtOH)-induced liver damages in C57BL/6 mice with its possible action mechanisms. EtOH-mediated acute hepatic damages were induced by oral administration of EtOH total 3 doses. The changes on the body weight, liver weight, albumin, TG, AST, ALP, ALT, hepatic TG contents, hepatic antioxidant defense system, TNF-α, CYP 2E1 activity and mRNA expressions of hepatic lipogenic genes - SREBP-1c, SCD1, ACC1, FAS, PPARγ and DGAT2 or genes involved in fatty acid oxidation - PPARα, ACO and CPT1 were observed with final liver histopathological inspections after 15 days of continuous administration of silymarin 200 ㎎/㎏, Gongjin-dan (GJD) 400, 200 and 100 ㎎/㎏. The results were compared with silymarin 200 ㎎/㎏ treated mice. Marked decreases of body and liver weights, increases of serum AST, ALT, Albumin and TG levels, hepatic TG contents, TNF-α level, CYP 2E1 activity and mRNA expressions of hepatic lipogenic genes or decreases mRNA expressions of genes involved in fatty acid oxidation were observed with histopathological changes related hepatosteatosis increases of immunolabelled hepatocytes, as the results of a binge drinking of EtOH in the present study. Also destroys of hepatic antioxidant defense systems were demonstrated in EtOH control mice as compared with intact vehicle control mice, respectively. The results suggest that oral administration of 400, 200 and 100 ㎎/㎏ of GJD favorably protected the liver damages from acute mouse EtOH intoxications.

Prepubertal heifers versus cows—The differences in the follicular environment

The oocyte quality is to a large extent influenced by the sexual maturity of the donor female. Although this phenomenon has already been broadly described in domestic animals, the underlying mechanisms are poorly understood. Published data focus on oocyte ultrastructure, fertilization abnormalities, and blastocyst developmental rate. The goal of the present experiment was to characterize the follicular environment (oocyte, cumulus [CC] and granulosa (GC) cells as well as follicular fluid [FF]) in ovarian follicles of prepubertal heifers and cows. Each experimental replicate included the following set of traits within individual follicles: lipid droplets (LDs) number in oocytes, expression of seven genes involved in energy metabolism (fatty acids [FAs] metabolism—ELOVL2, ELOVL5, SCD, FADS2, glucose transport—GLUT1, GLUT3, GLUT8) in CC and GC as well as FA composition and glucose concentration in FF. According to our results, cow oocytes were larger in diameter and contained more LD than those from prepubertal heifers, both before and after IVM. The LD number was also higher in cow oocytes after IVM, when compared to immature oocytes. The FF from cow follicles had elevated glucose content similarly to the majority of the analyzed FA. Transcript analysis revealed differences for five out of seven analyzed genes (ELOVL, FADS2, SCD, GLUT3, GLUT8) in CC and GC cells. However after considering the female category, the only difference was noticed for the mRNA of SCD gene, which was more abundant in cow GC. This finding may indicate distinct roles of CC and GC in follicular energy metabolism. In conclusions, we suggest that distinct properties of follicular environment in prepubertal heifers and cows may be responsible for differences in the quality of oocytes from the two categories of donors. We hypothesize that suboptimal environment in heifer follicles (glucose and FA lower content in FF) determines reduced quality of their oocytes (lower diameter and LD number) and limited maturation potential. Besides, energy demands of heifer oocytes may be restricted due to a low LD number, exerting a negative effect on the development of the future embryo. The advantages of cow gametes (e.g., higher LD number and diameter) attributed to oocytes of superior quality may support the statement that cows donate oocytes of better quality than heifers.