Transcriptomic profiles of Beauveria bassiana exposed to linoleic acid stress
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ABSTRACT: The entomopathogenici fungus B. bassiana is of great imporatnce in biological control of insect pests. In integrated pest management (IPM) program, unsaturated fatty acids and their derivatives are used as fungicides. The compatibility of mycoinsecticides with fungicides has attracted more and more attention. The genome-wide exprssion analysis involved in fungal resonse to unsaturated fatty acids was analyzed by using high throughput sequencing (RNA-Seq) at different concentrations of linoleic acid. Our transcriptional profiles revealed that numerous differentially expressed genes (DEGs), of which involved in metabolism, cell transport and cell rescue, were significantly involved in the tolerance of B. bassiana to linoleic acid stress.
Project description:Fungal tolerance is important for B. bassiana in biological control of insect pests. BbLar1 plays important roles in fungal resistance to linoleic acid stress. The genome-wide exprssion analysis involved in fungal resonse to unsaturated fatty acids was analyzed by using high throughput sequencing (RNA-Seq) at different concentrations of linoleic acid. Our analyese revealed that BbLar1 mediated numerous differentially expressed genes (DEGs), of which involved in metabolism, cell transport and cell rescue, were significantly involved in the tolerance of B. bassiana to linoleic acid stress.
Project description:Soybean oil consumption is increasing worldwide and parallels the obesity epidemic in the U.S. Rich in unsaturated fats, especially linoleic acid, soybean oil is assumed to be healthy, and yet it induces obesity, diabetes, insulin resistance and fatty liver in mice. The genetically modified soybean oil Plenish came on the U.S. market in 2014: it is low in linoleic acid and similar to olive oil in fatty acid composition. Here we show that Plenish induces less obesity than conventional soybean oil: metabolomics, proteomics and a transgenic mouse model implicate oxylipin metabolites of omega-6 and omega-3 fatty acids (linoleic and α-linolenic acid, respectively), which are generated by target genes of nuclear receptor HNF4α. While Plenish induces less insulin resistance than conventional soybean oil, it results in hepatomegaly and liver dysfunction as does olive oil. Altering the fatty acid profile of soybeans could help reduce obesity but may also cause liver complications.
Project description:Scope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Project description:Scope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Project description:Scope: Consumption of industrial trans fatty acids unfavourably alters plasma cholesterol and has been linked to NAFLD. However, the mechanisms underlying these deleterious effects of trans fatty acids are unclear. Here, we aim to investigate the molecular mechanisms of action of industrial trans fatty acids. Methods & Results: Hepa1-6 hepatoma cells were incubated with elaidate, oleate, or palmitate. C57Bl/6 mice were fed diets rich in trans-unsaturated, cis-unsaturated or saturated fatty acids. Transcriptomics analysis of Hepa1-6 cells showed that elaidate but not oleate or palmitate induced expression of genes involved in cholesterol biosynthesis. Induction of cholesterogenesis by elaidate was mediated by increased SREBP2 and dependent on SCAP, yet independent of LXR and UBXD8. Elaidate decreased intracellular free cholesterol levels and repressed the anti-cholesterogenic effect of exogenous cholesterol. In mice, the trans-unsaturated diet increased the ratio of liver to gonadal fat mass, steatosis, hepatic cholesterol levels, ALT activity, and fibrosis markers, suggesting enhanced NAFLD, compared to the cis-unsaturated and saturated diets. Conclusion: Elaidate induces cholesterogenesis in vitro via activation of the SCAP-SREBP axis, likely by lowering intracellular free cholesterol and attenuating cholesterol-dependent repression of SCAP. This pathway potentially underlies the increase in liver cholesterol and NAFLD by industrial trans fatty acids.
Project description:Methicillin-resistant Staphylococcus aureus (MRSA) infections result in more than 200,000 hospitalizations and 10,000 deaths in the United States each year and remain an important medical challenge. A key factor of S. aureus pathogenesis is the production of virulence proteins that are secreted into the extracellular matrix damaging host tissues and forming abscesses that may serve as replicative niches for the bacteria. We recently discovered that host-derived cis-unsaturated fatty acids activate the transcription and translation of EsxA, a protein that plays a central role in abscess formation in clinically relevant MRSA strains. Additionally, we discovered that fatty acid stimulation of EsxA is dependent on fakA, a gene that encodes a protein responsible for the incorporation of exogenous fatty acids into the S. aureus phospholipid membrane. In order to gain a comprehensive understanding of host-fatty-acid-sensing in S. aureus, we performed RNA-Seq analysis on WT Staphylococcus aureus USA300 NRS384, a community-acquired MRSA strain, in the presence and absence of 10μM linoleic acid.
Project description:Gene BbMbp1 playes an essential role in asexual differentiation, a determinant to the biocontrol potential of entomopathogenic fungi. The genome-wide exprssion analysis involved in fungal development was analyzed by using high throughput sequencing (RNA-Seq). Our transcriptional profiles revealed that numerous differentially expressed genes (DEGs), of which involved in metabolism, cell transport and cell rescue, were significantly involved in asexual deveopment of B. bassiana.
Project description:Soybean oil consumption is increasing worldwide and parallels the rise in obesity. Rich in unsaturated fats, especially linoleic acid, soybean oil is assumed to be healthy, and yet it induces obesity, diabetes, insulin resistance and fatty liver in mice. Here, we show that the genetically modified soybean oil Plenish, which came on the U.S. market in 2014 and is low in linoleic acid, induces less obesity than conventional soybean oil in C57BL/6male mice.
Project description:In the present study, we explored the hypothesis that the fatty liver phenotype and associated gene expression changes associated with the specific deletion of the POR gene in adult mouse liver could be abrogated by supplementation of the mouse diet with the very long chain highly unsaturated fatty acids, arachidonic acid (C20:4ω6), eicosapentaenoic acid (C20:5ω3) and docosahexaenoic acid (C22:6ω3). We expected the fatty liver phenotype would not be reduced by the polyunsaturated fatty acids linoleic (C18:2ω6) or linolenic acid (C18:3ω3), since these accumulated in the fatty livers of LivPORKO animals. This proved to be the case. However, we also made two surprising observations. First, control animals fed a diet enriched in PUFA had fatty livers and gene expression profiles similar to animals fed a lard diet, which was deficient in both PUFA and HUFA. Second, while a diet enriched in HUFA did result in reduced steatosis in livers of the LivPOKO animals, fat accumulation was still elevated relative to controls. Array analyses indicated most differences in gene expression were related to fatty acid metabolism and could explain differences in fat accumulation in LivPORKO livers with dietary treatment.
Project description:The low temperature normally applied to prevent fruit decay during the storage of apples, can also triggers the onset of a chilling injury disorder known as superficial scald. In this work, the etiology of this disorder and the mechanism of action of two preventing strategies, such as the application of 1-MCP and storage at low oxygen concentration in ‘Granny Smith’ and ‘Ladina’ apple cultivars was investigated. The metabolite assessment highlighted a reorganization of specific secondary metabolites, in particular flavan-3-ols (catechin, epicatechin and procyanidin B) and unsaturated fatty acids (oleic acid, linoleic acid and linolenic acid), while the genome-wide transcriptomic analysis grouped the DEGs into four functional clusters. The KEGG pathway, GO enrichment analysis, together with the gene-metabolite profiling interactome, showed as the treatment with 1-MCP prevented the development of superficial scald by actively promoting the production of unsaturated fatty acids, especially in ‘Granny Smith’. ‘Ladina’ was instead more susceptible to superficial scald, and characterized by a higher accumulation of very long chain fatty acids (VLCFAs). Storage at low oxygen concentration stimulated a higher accumulation of ethanol and acetaldehyde together with the expression of genes involved in anaerobic respiration, such as malate and alcohol dehydrogenase and pyruvate decarboxylase in both cultivars. Moreover, in ‘Granny Smith’ apple, the expression of three members of the VII subgroups of ERF genes, encoding for elements coordinating the acclimation process to hypoxia in plants was observed. The global RNA-Seq pattern also elucidated a specific transcriptomic signature between the two cultivars, validating the effect of the different genetic background in the control of this disorder.