Project description:Tree peony (Paeonia ostii section Moutan DC.) is known for its excellent ornamental and medicinal values. In 2011, seeds from P. ostii have been identified as novel resource of alpha-linolenic acid (ALA) for seed oil production and development in China. However, the molecular mechanism on biosynthesis of unsaturated fatty acids in tree peony seeds remains unknown. Therefore, transcriptome data is needed to better understand the underlying mechanisms. In this study, lipids accumulation contents were measured using GC-MS methods across developing tree peony seeds, which exhibited an extraordinary ALA content (49.3%) in P. ostii mature seeds. Transcriptome analysis was performed using Illumina sequencing platform. A total of 144 million 100-bp paired-end reads were generated from six libraries, which identified 175,874 contigs. In the KEGG Orthology enrichment of differentially expressed genes, lipid metabolism pathways were highly represented categories. Using this data we identified 388 unigenes that may be involved in de novo fatty acid and triacylglycerol biosynthesis. In particular, three unigenes (SAD, FAD2 and FAD8) encoding fatty acid desaturase with high expression levels in the fast oil accumulation stage compared with the initial stage of seed development were identified.
Project description:Systematic analyses of the temporal dynamics of transcriptomes and chromatin landscapes of macrophages during timecourse of TLR4-mediated inflammatory response. As a multifunctional effector cell, macrophages play pivotal roles in both the induction and resolution components of varied inflammatory processes. During the course of an inflammation response, macrophages engage in a homeostatic program characterized by tightly coordinated modulation of temporal outputs of both lipid metabolism and inflammation. We demonstrate inversely biphasic temporal dynamics of specific fatty acid metabolic and inflammatory gene expression profiles, associated with concordant temporal reprogramming of macrophage fatty acid profiles. In part, the late phase of the macrophage inflammatory response is characterized by tailoring of fatty acid related gene expressions, facilitating both significant induction of anti-inflammatory unsaturated fatty acid production and associated resolution of inflammation. We demonstrate the biphasic temporal dynamics of macrophage inflammation, specifically anti-inflammatory omega-3 and omega-9 unsaturated fatty acid levels, are transcriptionally driven genome-wide by an unexpected shift from an LXR to SREBP1-dominant regulatory program in the late phase inflammatory response. Collectively, our findings reveal a novel Srebp1-driven mechanism allowing the intimate inverse temporal relationship between the transcriptional regulation of inflammatory and fatty acid metabolic outputs; whereby modulation key transcriptional regulators (LXR, SREBP1 and NF-kB) of these pathways coordinate appropriate temporal tailoring of local enhancer associated reprogramming and eventual pathway regulatory interactions, during the course of TLR4-dependent inflammatory response in macrophages. This specific Srebp-driven, temporal reprogramming of macrophage fatty acid metabolism, characterized by late phase induction of anti-inflammatory unsaturated fatty acid production, is necessary for appropriate resolution of inflammation. Thus, this study suggests that selective reprogramming of macrophage lipid metabolism can serve as a viable therapeutic intervention aimed at ameliorating chronic inflammation and varied metabolic syndrome associated states.
Project description:Scd1 is responsible for forming a carbon-carbon double bound at the 9-10th position from the C-terminus of saturated fatty acids such as palmitic acid and stearic acid (C16:0 and C18:0), to generate the products of palmitoleic acid (C16:1) and oleic acid (C18:1).Here, we found SCD1 is required for in vitro blastocyst embryo development, and one of the mechanisms is through regulating unsaturated fatty acid-mediated membrane fluidity and formation of apical domain. Overall, our study provides invaluable resources for lipid reprogramming in mammalian preimplantation embryo development and mechanistic insights on regulation of embryogenesis by lipid unsaturation.
Project description:Sesamin, a special compound present in sesame and sesame oil, has been reported the role in regulating blood lipids and improving liver function, while the underlying mechanisms remain unclear. This study aims to explore its potential mechanisms in regulating lipid metabolism. HepG2 cells were treated with oleic acid to establish an in vitro high-fat cell model to simulate impaired hepatocytes under lipid metabolism disorders.Differentially expressed genes during the sesame intervention were screened by RNA sequencing (RNA seq) and validated using real-time quantitative PCR and Western blot.The data showed that sesamin significantly upregulated the mRNA levels of genes involved in fatty acid metabolism processes such as ETFB, ACAT2, FADS2, FABP1, ACOT1, and those involved in cholesterol metabolism processes such as FDPS, PCSK9, and DHCR7, and downregulated the mRNA levels of CYP24A1 and GGT5 involved in fatty acid metabolism, as well as MVK involved in cholesterol synthesis. Sesamin significantly down-regulated the protein levels of NOTCH1, CD36, SOX4, and FABP1. In summary, sesamin alleviates lipid accumulation in HepG2 by regulating lipid metabolism, with potential mechanisms involving steroid biosynthesis, unsaturated fatty acid biosynthesis, fat digestion and absorption, fatty acid metabolism, Notch signaling pathway, and PPAR signaling pathway.
Project description:There are two mating types, “+” and “-” strains in S. scitamineum. Generally, dikaryote cells are formed after fussion of the germ turbs from both mating type strains and filamentation (filamentous growth) with infection potential occur afterward. By introducing bE2 gene and/or orther related genes, derived from the opposite mating type strain JG36, haploid mutants with filamentation characteristics were generated, including M6,M8,M9 and M10. Among these are 446 genes that were found in both filamentous haploid strains, including 237 genes up-regulated and 209 genes down-regulated. The up-regulated genes were mainly enriched in amino acid biosynthesis, starch and sucrose metabolism, secondary metabolite biosynthesis, and pentose phosphate pathways. Down-regulated expression genes are mainly enriched in fatty acid synthesis and metabolism, homologous recombination, peroxides, biosynthesis of unsaturated fatty acids, ubiquitin-mediated protein hydrolysis and other metabolic pathways. Several MAP kinases and protein kinases were up- or down-regulated in the filamentous haploid.
Project description:Dietary unsaturated fatty acids beneficially affect human health, in part by modulating the immune system, but the mechanism is not completely understood. Given that unsaturated fatty acids have been shown to be covalently incorporated into a small subset of proteins, we designed three alkyne-tagged chemical reporters of unsaturated fatty acids, alk-16:1, alk-17:1 and alk-18:1, to explore the generality and diversity of this protein modification. Following cell lysis, proteins labelled with the reporters could be captured by azido-functionalized reagents via CuAAC for fluorescence detection or enrichment for proteomics analysis. These reporters label many proteins in mammalian cells and can be incorporated site-specifically, notably on Cys residues. Quantitative proteomics analysis (n= 4 biological replicates) of LPS/IFN-gamma stimulated RAW264.7 labelled with oleic acid (control), alk-16 (palmitic acid chemical reporter), alk-16:1, alk-17:1 and alk-18:1, revealed that unsaturated fatty acids modify similar protein targets to saturated fatty acids, including several immune proteins. Interestingly, some proteins can be differentially labeled with unsaturated and saturated fatty acid.
Project description:The aim of the present study was to correlate lipid metabolism genes in the mammary gland tissue affected by stage of lactation and nutrition to the resulting milk fatty acids composition in grazing dairy cows, and to classify milk fatty acid (FA) groups based on variations in lipid metabolism gene expression patterns. Identifying the relationship between lipid metabolism genes in the mammary gland tissue and the resulting milk fatty acid composition is expected to greatly contribute to our understanding of milk fatty acid metabolism and to enhance opportunities to improve milk fat composition through nutrition. In fact, SNCA, SCD5, and PNPLA2 lipid metabolism-related genes affected by unsaturated fatty acids supplementation, were found to strongly correlated to different milk FA groups, but also contributed most to the classification of these FA groups, suggesting a significant role in mediating the lipid metabolism in the mammary gland tissue and determining the milk fatty acids composition. A total of 28 Holstein-Friesian dairy cows in mid-lactation were blocked according to parity (2.4 ± 0.63 years), days in milk (DIM; 153 ± 32.8 days), milk yield (25.7 ± 3.08 kg/d) and fat content (4.3 ± 0.12%). Cows were then randomly assigned to four UFA-sources based on rapeseed, soybean, linseed or a mixture of the three oils for 23 days (Period I) after which, all 28 cows were switched to a control diet for an additional 28 days (Period II). On the last day of both periods, mammary gland biopsies were taken to study genome-wide differences in lipid metabolism gene expression.
Project description:Interactions between the gut microbial ecosystem and host lipid homeostasis are highly relevant to host physiology and metabolic diseases. We present a comprehensive multi-omics view of the effect of intestinal microbial colonization on hepatic lipid metabolism, integrating transcriptomic, proteomic, phosphoproteomic, and lipidomic analyses of liver and plasma samples from germfree and specific pathogen-free mice. Microbes induced monounsaturated fatty acid generation by stearoyl-CoA desaturase 1 and polyunsaturated fatty acid elongation by fatty acid elongase 5, leading to significant alterations in glycerophospholipid acyl-chain profiles. Germfree mice contained more abundant saturated and poly-unsaturated lipids, whereas colonized mice primarily contained mono-unsaturated lipids. A composite classification score calculated from the observed alterations in fatty acid profiles in germfree mice clearly differentiated antibiotic-treated mice from untreated controls with high sensitivity. Mechanistic investigations revealed that acetate originating from gut microbial degradation of dietary fiber serves as precursor for hepatic synthesis of C16 and C18 fatty acids and their related glycerophospholipid species that are also released into the circulation.