Proteomic and lipidomics analyses of high fatty acid AhDGAT3 transgenic soybean reveals the key lipase gene associated with the lipid internal mechanism

Vegetable oil is one of the most important components of human nutrition. Soybean (Glycine max) is an important oil crop worldwide and contains rich unsaturated fatty acids. Diacylglycerol acyltransferase (DGAT) is a key rate-limiting enzyme in the Kennedy pathway from diacylglycerol (DAG) to triacylglycerol (TAG). In this study, we conducted further research using T3 AhDGAT3 transgenic soybean. A high-performance gas chromatography flame ionization detector showed that oleic acid (18:1) content and total fatty acid content of transgenic soybean were significantly higher than those of the wild type (WT). However, linoleic acid (18:2) was much lower than that in the WT. For further mechanistic studies, 20 differentially expressed proteins (DEPs) and 119 differentially expressed metabolites (DEMs) were identified between WT (JACK) and AhDGAT3 transgenic soybean mature seeds using proteomic and lipidomics analyses. Combined proteomic and lipidomics analyses showed that the upregulation of the key DEP (lipase GDSL domain-containing protein) in lipid transport and metabolic process induced an increase in the total fatty acid and 18:1 composition, but a decrease in the 18:2 composition of fatty acids. Our study provides new insights into the deep study of molecular mechanism underlying the enhancement of fatty acids in transgenic soybeans, especially oleic acid and total fatty acid, which are enhanced by over-expression of AhDGAT3.

High-Fat Diets Containing Different Types of Fatty Acids Modulate Gut-Brain Axis in Obese Mice

Background: Excessive consumption of high-fat diets is associated with disordered metabolic responses, which may lead to chronic diseases. High-fat diets containing different types of fatty acids lead to distinct alterations in metabolic responses of gut-brain axis. Methods: In our study, normal male C57BL/6J mice were fed to multiple high fatty acid diets (long-chain and medium-chain saturated fatty acid, LCSFA and MCSFA group; n-3 and n-6 polyunsaturated fatty acid, n-3 and n-6 PUFA group; monounsaturated fatty acid, MUFA group; trans fatty acid, TFA group) and a basic diet (control, CON group) for 19 weeks. To investigate the effects of high-fat diets on metabolic responses of gut-brain axis in obese mice, blood lipids were detected by fast gas chromatography, and related proteins in brain and intestine were detected using Western blotting, ELISA, and immunochemistry analysis. Results: All high-fat diets regardless of their fatty acid composition induced obesity, lipid disorders, intestinal barrier dysfunction, and changes in gut-brain axis related factors except basal diet in mice. For example, the protein expression of zonula occludens-1 (ZO-1) in ileum in the n-3 PUFA group was higher than those in the MCSFA and CON group (all Ps < 0.05). The expressions of insulin in hippocampus and leptin in ileum in the MCSFA group were all higher than those in other groups (all Ps < 0.05). Conclusions: The high MCSFA diet had the most effect on metabolic disorders, and the high n-3 PUFA diet had the least effect on changes in metabolism.

The Essential Roles of Exosome and CircRNA_101093 to Desensitize Lung Adenocarcinoma to Ferroptosis

BackgroundResistance to ferroptosis, a regulated cell death caused by iron-dependent excessive accumulation of lipid peroxides has recently been linked to lung adenocarcinoma (LUAD), the most prevalent lung cancer subtype. Despite intracellular antioxidant system is required for protection against ferroptosis, whether and how extracellular system desensitizes LUAD cells to ferroptosis is incompletely known. MethodsImmunohistochemistry (IHC) and immunoblotting (IB) were used to analyze protein expression, and quantitative RT-PCR (qPCR) was used to analyze mRNA level. Cell viability, cell death and the lipid reactive oxygen species (ROS) generation were measured to evaluate the responses to ferroptosis induction. Metabolites were measured using appropriate kits. Exosomes were observed using transmission electron microscope (TEM). The localization of arachidonic acid (AA) was detected using click chemistry labeling followed by confocal microscope observation. Interaction between RNA and protein were detected using RNA-pulldown, RNA immunoprecipitation (RIP) and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP). Proteomic analysis was used to investigate circRNA_101093 (cir93) regulated protein and metabolomic analysis was used to analyze metabolites that changed among LUAD tissues expressing low and high Fatty acid-binding protein 3 (FABP3) levels. Cell-derived xenograft (CDX), patient-derived xenograft (PDX) and cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the mechanism that exosome and cir93 desensitized ferroptosis in LUAD. ResultsHere, the roles of exosome and circular RNA (circRNA) to desensitize LUAD cells to ferroptosis were investigated. Plasma exosome from LUAD patients exclusively reduced lipid peroxidation and desensitized ferroptosis. This might because exosomal-cir93 sustained an elevation of intracellular-cir93 in LUAD to modulate AA, a poly-unsaturated fatty acid that is critical for ferroptosis-associated over peroxidation in the plasma membrane. Mechanistically, cir93 interacted and lifted FABP3, which transported and facilitated AA reaction with taurine. Thus, global-AA was reduced while N-Arachidonoyl taurine (NAT), the product of AA and taurine, was induced. Notably, a role of NAT to suppress AA incorporation into plasma membrane was also revealed. In pre-clinical in vivo models, reducing exosome exhibited an improvement of ferroptosis-based treatment. ConclusionExosome and cir93 are essential for desensitizing LUAD cells to ferroptosis, and blocking exosome will be helpful for future LUAD treatment.

Classification of the multigene family of fatty acid binding proteins (FABPs) and transcription profile of the genes in striped catfish (Pangasianodon hypophthalmus)

Striped catfish (Pangasianodon hypophthalmus) is an economically important fish in Vietnam. The catfish fillets contain high fatty acid composition. The FABP family is involved in lipid transport and metabolism as well as in the regulation of gene expression and cell development. In this study, the catfish genome database was searched for fabp gene family; then, gene structure, classification and phylogenetic relationships were analyzed. In striped catfish genome, we found 10 fabp genes that are homologous to other fish species and other 5 novel fabp genes that have not been clearly annotated. These newly identified fabp genes cluster separately from the known members of the fabp family on the phylogenetic tree, and further studies are needed to understand their roles and functions. We examined transcriptional gene expression of fabp3, fabp7 and fabp10a genes in muscle, liver and brain tissues of the stripped catfish. The results showed that fabp10a gene was not strongly expressed in all 3 types of tissues; fabp3 gene was most strongly expressed in liver tissue and fabp7 was highly up-regulated in brain tissue. The results of this study provide a resource for further research on the function of fabp genes and their genetic diversity in striped catfish.

Obtaining Biodiesel by Direct Transesterification of Botryococcus braunii and Coccomyxa subellipsoidea

Biofuels have been obtained from vegetable oils, animal fats and recently from microorganisms such as algae, bacteria or yeasts that present a significant content of triacylglycerols through a transesterification reaction. Technical problems with biodiesel or agrodiesel (Term recently used, in this work we will use biodiesel), include oxidative stability, cold flow, and increased NOx emissions. The solution to these problems involves the use of additives on the one hand or modifying the fatty acid composition of the microorganisms alternatively, either through changes in the cultivation temperature, addition of nanomaterials, or through genetic modification, to obtain high-quality biofuels. In this work, two species of microalgae with high fatty acid content were obtained, Botryococcus braunii originating from Cuzco, Peru and Coccomyxa subellipsoidea C-169, from Marble Point, Antarctica, both were cultivated under optimal conditions and later direct transesterification was performed to obtaining biodiesel. The main objective was to develop an economical and viable process that allows it to compete with fossil fuels, based on obtaining biomass and the transesterification method. Here, direct transesterification was effective and allows to significantly reduce the problems associated with the increase in costs of obtaining biodiesel, because reduces critical steps, also the biodiesel thus obtained represents an advance in the development of high-quality biofuels, large-scale and inexpensive. Resumen. Los biocombustibles se han obtenido desde finales del siglo XIX a partir de aceites vegetales, grasas animales y recientemente a partir de microorganismos como algas, bacterias o levaduras que presentan un contenido significativo en triacilgliceroles mediante una reacción de transesterificación. Algunos de los problemas técnicos con el biodiésel o agrodiesel (término usado recientemente, en este trabajo usaremos biodiesel) son: estabilidad oxidativa, flujo en frío y aumento de emisiones de NOx. La solución a estos problemas incluye el uso de aditivos, por un lado, o modificar la composición de ácidos grasos de los microorganismos por otro, ya sea mediante cambios en la temperatura de cultivo, adición de nanomateriales, o mediante modificación genética, para obtener biocombustibles de alta calidad. En este trabajo se utilizaron dos especies de microalgas con gran contenido en ácidos grasos, Botryococcus braunii originaria de Cuzco, Perú y Coccomyxa subellipsoidea C-169, de Punta Mármol, Antártida, ambas fueron cultivadas en óptimas condiciones y posteriormente se realizó la transesterificación directa para obtener el biodiésel. El principal objetivo fue desarrollar un proceso económico y viable, que permita competir con los combustibles fósiles, a partir de la obtención de biomasa y el proceso de transesterificación. La transesterificación directa fue exitosa y permitió reducir significativamente los problemas asociados con el aumento de costos de obtención de biodiésel, ya que reduce pasos críticos del proceso, además el biodiésel así obtenido representa un avance en el desarrollo de biocombustibles de alta calidad, a gran escala y de bajo costo.

Biodiesel Fuel from Waste Cooking Oil: A Cheaper and Cleaner Renewable Energy Source

Low cost, high fatty acid content waste cooking oil was transformed into biodiesel using an acid catalyzed chemical esterification reaction with 0.5 vol.% of H2SO4 at 60�C for 1 hour followed by the main transesterification reaction. For the purpose of comparison, biodiesel fuel was also prepared using straight vegetable oils (SVO�s). The gas chromatography test showed higher than 95% FAME (fatty acid methyl ester) content for different types of utilized feedstocks. Biodiesel fuel and its blends were characterized based on ASTM test methods to investigate its density, viscosity, flash point, pour point, heating value, and its cetane index and similar physical properties were obtained for all the prepared biodiesel fuels. B20 blend, which contains 20 vol.% of biodiesel and 80 vol.% of diesel, showed a better performance than B0 (100 vol.% of diesel) when tested in a laboratory compression ignition diesel engine. After simulation of the production process via Aspen Hysys, a feasibility study was conducted and the results revealed that utilizing waste cooking oils (WCO�s) as feedstock is more economical than starting with SVO�s as raw material.

The hepatic lipidome and HNF4α and SHBG expression in human liver

Low plasma levels of sex hormone-binding globulin (SHBG) are a marker for obesity, insulin resistance, non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes. The transcription factor HNF4α is a major determinant of hepatic SHBG expression and thereby serum SHBG levels, and mediates in part the association of low SHBG with hyperinsulinemia and hepatic steatosis. We analyzed the lipidome in human liver specimens from a cohort of patients who underwent hepatic resection as a treatment for cancer, providing insight into hepatic lipids in those without extreme obesity or the clinical diagnosis of NAFLD or non-alcoholic steatohepatitis. Both steatosis and high HOMA-IR were associated with higher levels of saturated and unsaturated FA, other than arachidonic, with the most dramatic rise in 18:1 oleate, consistent with increased stearoyl-CoA desaturase activity. Individuals with low HOMA-IR had low levels of total hepatic fatty acids, while both low and high fatty acid levels characterized the high HOMA-IR group. Both insulin resistance and high levels of hepatic fat were associated with low expression levels of HNF4α and thereby SHBG, but the expression of these genes was also low in the absence of these determinants, implying additional regulatory mechanisms that remain to be determined. The relationship of all FA studied to HNFα and SHBG mRNAs was inverse, and similar to that for total triglyceride concentrations, irrespective of chain length and saturation vs unsaturation.

Diet-induced obese mouse hearts tolerate an acute high-fatty acid exposure that also increases ischemic tolerance

An acute myocardial fat-load leads to oxidative stress, oxygen wasting, mechanical inefficiency, hyperacetylation, and impaired mitochondrial function, which can contribute to reduced ischemic tolerance. Following obesity/insulin resistance, hearts were less affected by a high fat-load, which subsequently also improved ischemic tolerance. This study highlights that an acute fat-load affects normal and obese hearts differently and that obesity renders hearts less vulnerable to the disadvantageous effects of an acute fat-load.

Ketones can become the major fuel source for the heart but do not increase cardiac efficiency

Aims Ketones have been proposed to be a ‘thrifty’ fuel for the heart and increasing cardiac ketone oxidation can be cardioprotective. However, it is unclear how much ketone oxidation can contribute to energy production in the heart, nor whether increasing ketone oxidation increases cardiac efficiency. Therefore, our goal was to determine to what extent high levels of the ketone body, β-hydroxybutyrate (βOHB), contributes to cardiac energy production, and whether this influences cardiac efficiency. Methods and results Isolated working mice hearts were aerobically perfused with palmitate (0.8 mM or 1.2 mM), glucose (5 mM) and increasing concentrations of βOHB (0, 0.6, 2.0 mM). Subsequently, oxidation of these substrates, cardiac function, and cardiac efficiency were assessed. Increasing βOHB concentrations increased myocardial ketone oxidation rates without affecting glucose or fatty acid oxidation rates where normal physiological levels of glucose (5 mM) and fatty acid (0.8 mM) are present. Notably, ketones became the major fuel source for the heart at 2.0 mM βOHB (at both low or high fatty acid concentrations), with the elevated ketone oxidation rates markedly increasing tricarboxylic acid (TCA) cycle activity, producing a large amount of reducing equivalents and finally, increasing myocardial oxygen consumption. However, the marked increase in ketone oxidation at high concentrations of βOHB was not accompanied by an increase in cardiac work, suggesting that a mismatch between excess reduced equivalents production from ketone oxidation and cardiac adenosine triphosphate production. Consequently, cardiac efficiency decreased when the heart was exposed to higher ketone levels. Conclusions We demonstrate that while ketones can become the major fuel source for the heart, they do not increase cardiac efficiency, which also underscores the importance of recognizing ketones as a major fuel source for the heart in times of starvation, consumption of a ketogenic diet or poorly controlled diabetes.

Gut Microbiota, Its Role in Induction of Alzheimer’s Disease Pathology, and Possible Therapeutic Interventions: Special Focus on Anthocyanins

The human gut is a safe environment for several microbes that are symbiotic and important for the wellbeing of human health. However, studies on gut microbiota in different animals have suggested that changes in the composition and structure of these microbes may promote gut inflammation by releasing inflammatory cytokines and lipopolysaccharides, gut-wall leakage, and may affect systemic inflammatory and immune mechanisms that are important for the normal functioning of the body. There are many factors that aid in the gut’s dysbiosis and neuroinflammation, including high stress levels, lack of sleep, fatty and processed foods, and the prolonged use of antibiotics. These neurotoxic mechanisms of dysbiosis may increase susceptibility to Alzheimer’s disease (AD) and other neurodegenerative conditions. Therefore, studies have recently been conducted to tackle AD-like conditions by specifically targeting gut microbes that need further elucidation. It was suggested that gut dyshomeostasis may be regulated by using available options, including the use of flavonoids such as anthocyanins, and restriction of the use of high-fatty-acid-containing food. In this review, we summarize the gut microbiota, factors promoting it, and possible therapeutic interventions especially focused on the therapeutic potential of natural dietary polyflavonoid anthocyanins. Our study strongly suggests that gut dysbiosis and systemic inflammation are critically involved in the development of neurodegenerative disorders, and the natural intake of these flavonoids may provide new therapeutic opportunities for preclinical or clinical studies.