Maternal Diet High in Linoleic Acid Alters Renal Branching Morphogenesis and mTOR/AKT Signalling Genes in Rat Fetal Kidneys.

Linoleic acid (LA), an n-6 polyunsaturated fatty acid (PUFA), is obtained from the maternal diet during pregnancy, and is essential for normal fetal growth and development. A maternal high-LA (HLA) diet alters maternal and offspring fatty acids, maternal leptin and male/female ratio at embryonic (E) day 20 (E20). We investigated the effects of an HLA diet on embryonic offspring renal branching morphogenesis, leptin signalling, megalin signalling and angiogenesis gene expression. Female Wistar Kyoto rats were fed low-LA (LLA; 1.44% energy from LA) or high-LA (HLA; 6.21% energy from LA) diets during pregnancy and gestation/lactation. Offspring were sacrificed and mRNA from kidneys was analysed by real-time PCR. Maternal HLA decreased the targets involved in branching morphogenesis Ret and Gdnf in offspring, independent of sex. Furthermore, downstream targets of megalin, namely mTOR, Akt3 and Prkab2, were reduced in offspring from mothers consuming an HLA diet, independent of sex. There was a trend of an increase in the branching morphogenesis target Gfra1 in females (p = 0.0517). These findings suggest that an HLA diet during pregnancy may lead to altered renal function in offspring. Future research should investigate the effects an HLA diet has on offspring kidney function in adolescence and adulthood.

Integrated Transcriptomic and Metabolomic Analysis Reveal the Dynamic Process of Bama Hemp Seed Development and the Accumulation Mechanism of α-Linolenic Acid and Linoleic Acid.

Bama County is a world-famous longevity county in the Guangxi Province, China. Bama hemp is a traditional seed used in hemp cultivation in the Bama County. The seeds contain abundant unsaturated fatty acids, particularly linoleic acid (LA) and linolenic acid in the golden ratio. These two substances have been proven to be related to human health and the prevention of various diseases. However, the seed development and seed oil accumulation mechanisms remain unclear. This study employed a combined analysis of physiological, transcriptomic, and metabolomic parameters to elucidate the fatty acid formation patterns in Bama hemp seeds throughout development. We found that seed oil accumulated at a late stage in embryo development, with seed oil accumulation following an "S″-shaped growth curve, and positively correlated with seed size, sugar content, protein content, and starch content. Transcriptome analysis identified genes related to the metabolism of LA, α-linolenic acid (ALA), and jasmonic acid (JA). We found that the FAD2 gene was upregulated 165.26 folds and the FAD3 gene was downregulated 6.15 folds at day 21. Metabolomic changes in LA, ALA, and JA compounds suggested a competitive relationship among these substances. Our findings indicate that the peak period of substance accumulation and nutrient accumulation in Bama hemp seeds occurs during the midstage of seed development (day 21) rather than in the late stage (day 40). The results of this research will provide a theoretical basis for local cultivation and deep processing of Bama hemp.

The Composition of Volatiles and the Role of Non-Traditional LOX on Target Metabolites in Virgin Olive Oil from Autochthonous Dalmatian Cultivars.

The lipoxygenase pathway has a significant influence on the composition of the volatile components of virgin olive oil (VOO). In this work, the influence of the maturity index (MI) on the activity of the lipoxygenase enzyme (LOX) in the fruits of the autochthonous Dalmatian olive cultivars Oblica, Levantinka and Lastovka was studied. The analysis of the primary oxidation products of linoleic acid in the studied cultivars showed that LOX synthesises a mixture of 9- and 13-hydroperoxides of octadecenoic acid in a ratio of about 1:2, which makes it a non-traditional plant LOX. By processing the fruits of MI~3, we obtained VOOs with the highest concentration of desirable C6 volatile compounds among the cultivars studied. We confirmed a positive correlation between MI, the enzyme activity LOX and the concentration of hexyl acetate and hexanol in cultivars Oblica and Lastovka, while no positive correlation with hexanol was observed in the cultivar Levantinka. A significant negative correlation was found between total phenolic compounds in VOO and LOX enzyme activity, followed by an increase in the MI of fruits. This article contributes to the selection of the optimal harvest time for the production of VOOs with the desired aromatic properties and to the knowledge of the varietal characteristics of VOOs.

Functional metabolomics reveals arsenic-induced inhibition of linoleic acid metabolism in mice kidney in drinking water.

Arsenic (As) is a heavy metal known for its detrimental effects on the kidneys, but the precise mechanisms underlying its toxicity remain unclear. In this study, we employed an integrated approach combining traditional toxicology methods with functional metabolomics to explore the nephrotoxicity induced by As in mice. Our findings demonstrated that after 28 days of exposure to sodium arsenite, blood urea nitrogen, serum creatinine levels were significantly increased, and pathological examination of the kidneys revealed dilation of renal tubules and glomerular injury. Additionally, uric acid, total cholesterol, and low-density lipoprotein cholesterol levels were significant increased while triglyceride level was decreased, resulting in renal insufficiency and lipid disorders. Subsequently, the kidney metabolomics analysis revealed that As exposure disrupted 24 differential metabolites, including 14 up-regulated and 10 down-regulated differential metabolites. Ten metabolic pathways including linoleic acid and glycerophospholipid metabolism were significantly enriched. Then, 80 metabolic targets and 168 predicted targets were identified using metabolite network pharmacology analysis. Of particular importance, potential toxicity targets, such as glycine amidinotransferase, mitochondrial (GATM), and nitric oxide synthase, and endothelial (NOS3), were prioritized through the "metabolite-target-pathway" network. Receiver operating characteristics curve and molecular docking analyses suggested that 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, linoleic acid, and L-hydroxyarginine might be functional metabolites associated with GATM and NOS3. Moreover, targeted verification result showed that the level of linoleic acid in As group was 0.4951 µg/mL, which was significantly decreased compared with the control group. And in vivo and in vitro protein expression experiments confirmed that As exposure inhibited the expression of GATM and NOS3. In conclusion, these results suggest that As-induced renal injury may be associated with the inhibition of linoleic acid metabolism through the down-regulation of GATM and NOS3, resulting in decreased levels of linoleic acid, 1-palmitoyl-2-myristoyl-sn-glycero-3-PC, and L-hydroxyarginine metabolites.

Impact of changes in root biomass on the occurrence of internal browning in radish root.

The purpose of this study was to investigate the effects of root biomass during the later stage of growth on fatty acid composition and lipid peroxidation, and to clarify the physiological mechanisms by which these differences affect internal browning (IB) development in radish roots. Therefore, we controlled the enlargement of roots by changing the thinning period and generated plots composed of roots with different biomass in the latter half of growth. The earlier the radish seedlings were thinned, the more vigorous the root growth from an earlier stage was achieved. Earlier thinning caused IB from the early stage of root maturation, and IB severity progressed with subsequent age progression; however, IB damage did not occur when root size during the later growth stage was kept small by later thinning. Higher levels of hydrogen peroxide, peroxidase activity, NADPH-dependent reactive oxygen species (ROS) burst-related genes, and carbonyl compounds were detected in earlier-thinned large-sized roots compared to later-thinned small-sized ones. Compared with the latter small-sized roots, the former large-sized roots had a lower ratio of linoleic acid (18:2) and a higher ratio of α-linolenic acid (α-18:3). Furthermore, in earlier-thinned large-sized roots, higher levels of phospholipase- and/or lipoxygenase-related genes were detected compared to later-thinned small-sized ones. These facts suggest the possibility that root biomass in the later stage of growth affects the desaturation of membrane fatty acids, ROS concentration, and activity of fatty acid degrading enzymes, and controls the occurrence of IB injury through membrane oxidative degradation.

Inflammatory response in dairy cows caused by heat stress and biological mechanisms for maintaining homeostasis.

Climate change increases global temperatures, which is lethal to both livestock and humans. Heat stress is known as one of the various livestock stresses, and dairy cows react sensitively to high-temperature stress. We aimed to better understand the effects of heat stress on the health of dairy cows and observing biological changes. Individual cows were divided into normal (21-22 °C, 50-60% humidity) and high temperature (31-32 °C, 80-95% humidity), respectively, for 7-days. We performed metabolomic and transcriptome analyses of the blood and gut microbiomes of feces. In the high-temperature group, nine metabolites including linoleic acid and fructose were downregulated, and 154 upregulated and 72 downregulated DEGs (Differentially Expressed Genes) were identified, and eighteen microbes including Intestinimonas and Pseudoflavonifractor in genus level were significantly different from normal group. Linoleic acid and fructose have confirmed that associated with various stresses, and functional analysis of DEG and microorganisms showing significant differences confirmed that high-temperature stress is related to the inflammatory response, immune system, cellular energy mechanism, and microbial butyrate production. These biological changes were likely to withstand high-temperature stress. Immune and inflammatory responses are known to be induced by heat stress, which has been identified to maintain homeostasis through modulation at metabolome, transcriptome and microbiome levels. In these findings, heat stress condition can trigger alteration of immune system and cellular energy metabolism, which is shown as reduced metabolites, pathway enrichment and differential microbes. As results of this study did not include direct phenotypic data, we believe that additional validation is required in the future. In conclusion, high-temperature stress contributed to the reduction of metabolites, changes in gene expression patterns and composition of gut microbiota, which are thought to support dairy cows in withstanding high-temperature stress via modulating immune-related genes, and cellular energy metabolism to maintain homeostasis.

Linoleic acid induces human ovarian granulosa cell inflammation and apoptosis through the ER-FOXO1-ROS-NFκB pathway.

Polycystic ovary syndrome (PCOS) is a complex reproductive endocrinological disorder influenced by a combination of genetic and environmental factors. Linoleic acid (LA) is a widely consumed ω-6 polyunsaturated fatty acid, accounting for approximately 80% of daily fatty acid intake. Building upon the prior investigations of our team, which established a connection between LA levels in the follicular fluid and PCOS, this study deeply examined the specific impact of LA using a granulosa cell line. Our findings revealed that LA exerts its influence on granulosa cells (GCs) by binding to the estrogen receptor (ER). Activated ER triggers the transcription of the FOXO1 gene. Reactive oxygen species (ROS)-related oxidative stress (OS) and inflammation occur downstream of LA-induced FOXO1 activation. Increased OS and inflammation ultimately culminate in GC apoptosis. In summary, LA modulates the apoptosis and inflammation phenotypes of GCs through the ER-FOXO1-ROS-NF-κB pathway. Our study provides additional experimental evidence to comprehend the pathophysiology of PCOS and provides novel insights into the dietary management of individuals with PCOS.

Simultaneous production of algal biomass and lipid by heterotrophic cultivation of linoleic acid-rich oleaginous microalga Chlorella sorokiniana using high acetate dosage.

The low-cost carbon source, acetate, was utilized to feed a linoleic acid-rich Chlorella sorokiniana for microalgal biomass and lipid accumulation. Remarkably high tolerance capability to high acetate dosage up to 30 g/L was observed, with heterotrophy being the preferred trophic mode for algal growth and lipogenesis when supplemented 20 g/L acetate. Transcriptome analysis revealed a marked activation of pathways involved in acetate bioconversion and lipogenesis upon exposure to high-level of acetate. However, the enhancement of photorespiration inhibited photosynthesis, which ultimately led to a decrease in biomass and lipid under mixotrophy. Heterotrophic acetate-feeding generated more superior amino acid profiling of algal biomass and a predominant linoleic acid content (50 %). Heterotrophic repeat fed-batch strategy in 5 L fermenter significantly increased the growth performance and lipid titer, with the highest levels achieved being 23.4 g/L and 7.0 g/L, respectively. This work provides a viable approach for bio-products production through acetate-based heterotrophic algal cultivation.

Pla2g5 contributes to viral-like-induced lung inflammation through macrophage proliferation and LA/Ffar1 lung cell recruitment.

Macrophages expressing group V phospholipase A2 (Pla2g5) release the free fatty acid (FFA) linoleic acid (LA), potentiating lung type 2 inflammation. Although Pla2g5 and LA increase in viral infections, their role remains obscure. We generated Pla2g5flox/flox mice, deleted Pla2g5 by using the Cx3cr1cre transgene, and activated bone marrow-derived macrophages (BM-Macs) with poly:IC, a synthetic double-stranded RNA that triggers a viral-like immune response, known Pla2g5-dependent stimuli (IL-4, LPS + IFNγ, IL-33 + IL-4 + GM-CSF) and poly:IC + LA followed by lipidomic and transcriptomic analysis. Poly:IC-activated Pla2g5flox/flox;Cx3cr1cre/+ BM-Macs had downregulation of major bioactive lipids and critical enzymes producing those bioactive lipids. In addition, AKT phosphorylation was lower in poly:IC-stimulated Pla2g5flox/flox;Cx3cr1cre/+ BM-Macs, which was not restored by adding LA to poly:IC-stimulated BM-Macs. Consistently, Pla2g5flox/flox;Cx3cr1cre/+ mice had diminished poly:IC-induced lung inflammation, including inflammatory macrophage proliferation, while challenging Pla2g5flox/flox;Cx3cr1cre/+ mice with poly:IC + LA partially restored lung inflammation and inflammatory macrophage proliferation. Finally, mice lacking FFA receptor-1 (Ffar1)-null mice had reduced poly:IC-induced lung cell recruitment and tissue macrophage proliferation, not corrected by LA. Thus, Pla2g5 contributes to poly:IC-induced lung inflammation by regulating inflammatory macrophage proliferation and LA/Ffar1-mediated lung cell recruitment and tissue macrophage proliferation.

PNPLA1 knockdown inhibits esterification of γ-linolenic acid to ceramide 1 in differentiated keratinocytes.

Patatin-like phospholipase domain-containing 1 (PNPLA1) is crucial in the esterification of linoleic acid (LA; 18:2n-6) to ω-hydroxy fatty acids (FA) of ceramide 1 (Cer1), the major barrier lipid of the differentiated epidermis. We previously reported that γ-linolenic acid (GLA; 18:3n-6) as well as LA is esterified to Cer1 subspecies with sphingosine (d18:1) or eicosasphingosine (d20:1) amide-linked to two different ω-hydroxy FA (30wh:0; 32wh:1). Here, we further investigated whether PNPLA1 is also responsible for esterification of GLA to these Cer1 subspecies in normal human keratinocytes (NHK). As late/terminal differentiation was induced in NHK, PNPLA1 and differentiation markers were expressed, and LA-esterified Cer1 subspecies (18:2n-6/C30wh:0 or C32wh:0/d18:1; 18:2n-6/C32wh:0/d20:1) were detected, which were further increased with LA treatment. GLA-esterified Cer1 subspecies (18:3n-6/C30wh:0 or C32wh:0/d18:1; 18:3n-6/C32wh:0/d20:1) were detected only with GLA treatment. Specific small interfering RNA-mediated knockdown of PNPLA1 (KDP) in differentiated NHK decreased levels of these LA-esterified Cer1 subspecies overall and of involucrin (IVL), a terminal differentiation marker. Moreover, KDP resulted in lesser LA/GLA responses as characterized by more significant decreases in IVL and LA/GLA-esterified Cer1 subspecies overall and an accumulation of non-esterified ω-hydroxy ceramides, their putative precursors; the decrease of 18:3n-6/C32wh:0/d18:1, the predominant GLA-esterified Cer1 subspecies, specifically paralleled the increase of C32wh:0/d18:1, its corresponding precursor. PNPLA1 is responsible for NHK terminal differentiation and also for esterification of GLA to the ω-hydroxy FA of Cer1.

Porphyromonas gingivalis aggravates colitis via a gut microbiota-linoleic acid metabolism-Th17/Treg cell balance axis.

Periodontitis is closely related to inflammatory bowel disease (IBD). An excessive and non-self-limiting immune response to the dysbiotic microbiome characterizes the two. However, the underlying mechanisms that overlap still need to be clarified. We demonstrate that the critical periodontal pathogen Porphyromonas gingivalis (Pg) aggravates intestinal inflammation and Th17/Treg cell imbalance in a gut microbiota-dependent manner. Specifically, metagenomic and metabolomic analyses shows that oral administration of Pg increases levels of the Bacteroides phylum but decreases levels of the Firmicutes, Verrucomicrobia, and Actinobacteria phyla. Nevertheless, it suppresses the linoleic acid (LA) pathway in the gut microbiota, which was the target metabolite that determines the degree of inflammation and functions as an aryl hydrocarbon receptor (AHR) ligand to suppress Th17 differentiation while promoting Treg cell differentiation via the phosphorylation of Stat1 at Ser727. Therapeutically restoring LA levels in colitis mice challenged with Pg exerts anti-colitis effects by decreasing the Th17/Treg cell ratio in an AHR-dependent manner. Our study suggests that Pg aggravates colitis via a gut microbiota-LA metabolism-Th17/Treg cell balance axis, providing a potential therapeutically modifiable target for IBD patients with periodontitis.

[What is the Initiating Reaction for the Lipid Radical Chain Reaction System That Can Induce Ferroptotic Cell Death at the Lower Oxygen Content?]

The neural cell death in cerebral infarction is suggested to be ferroptosis-like cell death, involving the participation of 15-lipoxygenase (15-LOx). Ferroptosis is induced by lipid radical species generated through the one-electron reduction of lipid hydroperoxides, and it has been shown to propagate intracellularly and intercellularly. At lower oxygen concentration, it appeared that both regiospecificity and stereospecificity of conjugated diene moiety in lipoxygenase-catalysed lipid hydroperoxidation are drastically lost. As a result, in the reaction with linoleic acid, the linoleate 9-peroxyl radical-ferrous lipoxygenase complex dissolves into the linoleate 9-peroxyl radical and ferrous 15-lipoxygenase. Subsequently, the ferrous 15-lipoxygenase then undergoes one-electron reduction of 13-hydroperoxy octadecadienoic acid, generating an alkoxyl radical (pseudoperoxidase reaction). A part of the produced lipid alkoxyl radicals undergoes cleavage of C-C bonds, liberating small molecular hydrocarbon radicals. Particularly, in ω-3 polyunsaturated fatty acids, which are abundant in the vascular and nervous systems, the liberation of small molecular hydrocarbon radicals was more pronounced compared to ω-6 polyunsaturated fatty acids. The involvement of these small molecular hydrocarbon radicals in the propagation of membrane lipid damage is suggested.

Role of the soluble epoxide hydrolase in keratinocyte proliferation and sensitivity of skin to inflammatory stimuli.

The lipid content of skin plays a determinant role in its barrier function with a particularly important role attributed to linoleic acid and its derivatives. Here we explored the consequences of interfering with the soluble epoxide hydrolase (sEH) on skin homeostasis. sEH; which converts fatty acid epoxides generated by cytochrome P450 enzymes to their corresponding diols, was largely restricted to the epidermis which was enriched in sEH-generated diols. Global deletion of the sEH increased levels of epoxides, including the linoleic acid-derived epoxide; 12,13-epoxyoctadecenoic acid (12,13-EpOME), and increased basal keratinocyte proliferation. sEH deletion (sEH-/- mice) resulted in thicker differentiated spinous and corneocyte layers compared to wild-type mice, a hyperkeratosis phenotype that was reproduced in wild-type mice treated with a sEH inhibitor. sEH deletion made the skin sensitive to inflammation and sEH-/- mice developed thicker imiquimod-induced psoriasis plaques than the control group and were more prone to inflammation triggered by mechanical stress with pronounced infiltration and activation of neutrophils as well as vascular leak and increased 12,13-EpOME and leukotriene (LT) B4 levels. Topical treatment of LTB4 antagonist after stripping successfully inhibited inflammation and neutrophil infiltration both in wild type and sEH-/- skin. While 12,13-EpoME had no effect on the trans-endothelial migration of neutrophils, like LTB4, it effectively induced neutrophil adhesion and activation. These observations indicate that while the increased accumulation of neutrophils in sEH-deficient skin could be attributed to the increase in LTB4 levels, both 12,13-EpOME and LTB4 contribute to neutrophil activation. Our observations identify a protective role of the sEH in the skin and should be taken into account when designing future clinical trials with sEH inhibitors.

Analysis of lipid metabolites derived from gut microbiota in ischemia-reperfusion model.

BACKGROUND: Disruption of intestinal barrier caused by intestinal ischemia due to hemorrhagic shock is associated with the pathogenesis of multiple organ dysfunction (MOD) after severe trauma. Mesenteric lymph (ML) plays an important role as a route for transporting inflammatory mediators, including lipids. Postbiotics, such as 10-hydroxy-cis-12-octadecenoic acid (HYA), have received much attention as a treatment option. However, the relationship between postbiotics and MOD has yet to be clarified. The aim of the present study was to analyze lipid metabolites derived from gut microbiota in the intestinal ischemia-reperfusion (IR) rat model. METHODS: Male Sprague-Dawley rats underwent laparotomy, and their ML duct and superior mesenteric artery were exposed. The superior mesenteric artery was clamped for 60 minutes, followed by 120 minutes of reperfusion. The ML and the plasma were collected before and after intestinal IR. Lipids were extracted from plasma and ML, and liquid chromatography-tandem mass spectrometry was performed. RESULTS: The concentration of linoleic acid in plasma samples was not different before and after IR; however, the linoleic acid concentration in the ML samples increased after intestinal IR. Eicosapentaenoic acids and docosahexaenoic related to linoleic acids showed similar changes with IR-induced increase in the ML. The concentration of HYA, a linoleic acid-derived bioactive metabolite produced by gut bacteria, was high in ML samples, while that in plasma samples was low. The relative increase rate of HYA in ML samples after IR was higher than that of the plasma samples (the ML samples: relative increase, 3.23 ± 1.36; the plasma samples: relative increase, 0.95 ± 0.35; n = 3, p = 0.048). CONCLUSION: The present study demonstrated increased linoleic acids and high concentrations of HYA, lipid metabolites derived from gut bacteria in the ML after intestinal IR. These findings may contribute to clarifying the relation between gut microbiota and MOD after severe trauma.

Important roles of linoleic acid and α-linolenic acid in regulating cognitive impairment and neuropsychiatric issues in metabolic-related dementia.

Metabolic syndrome (MetS), which is characterized by insulin resistance, high blood glucose, obesity, and dyslipidemia, is known to increase the risk of dementia accompanied by memory loss and depression. The direct pathways and specific mechanisms in the central nervous system (CNS) for addressing fatty acid imbalances in MetS have not yet been fully elucidated. Among polyunsaturated acids, linoleic acid (LA, n6-PUFA) and α-linolenic acid (ALA, n3-PUFA), which are two essential fatty acids that should be provided by food sources (e.g., vegetable oils and seeds), have been reported to regulate various cellular mechanisms including apoptosis, inflammatory responses, mitochondrial biogenesis, and insulin signaling. Furthermore, inadequate intake of LA and ALA is reported to be involved in neuropathology and neuropsychiatric diseases as well as imbalanced metabolic conditions. Herein, we review the roles of LA and ALA on metabolic-related dementia focusing on insulin resistance, dyslipidemia, synaptic plasticity, cognitive function, and neuropsychiatric issues. This review suggests that LA and ALA are important fatty acids for concurrent treatment of both MetS and neurological problems.

Cholesterol is more readily oxidized than phospholipid linoleates in cell membranes to produce cholesterol hydroperoxides.

Cholesterol is an essential component of cell membranes and serves as an important precursor of steroidal hormones and bile acids, but elevated levels of cholesterol and its oxidation products have been accepted as a risk factor for maintenance of health. The free and ester forms of cholesterol and fatty acids are the two major biological lipids. The aim of this hypothesis paper is to address the long-standing dogma that cholesterol is less susceptible to free radical peroxidation than polyunsaturated fatty acids (PUFAs). It has been observed that cholesterol is peroxidized much slower than PUFAs in plasma but that, contrary to expectations from chemical reactivity toward peroxyl radicals, cholesterol appears to be more readily autoxidized than linoleates in cell membranes. The levels of oxidation products of cholesterol and linoleates observed in humans support this notion. It is speculated that this discrepancy is ascribed to the fact that cholesterol and phospholipids bearing PUFAs are localized apart in raft and non-raft domains of cell membranes respectively and that the antioxidant vitamin E distributed predominantly in the non-raft domains cannot suppress the oxidation of cholesterol lying in raft domains which are relatively deficient in antioxidant.

Differences in Absorption and Metabolism between Structured 1,3-Oleate-2-palmitate Glycerol and 1-Oleate-2-palmitate-3-linoleate Glycerol on C57BL/6J Mice.

This study investigated differences in absorption and metabolism between 1,3-oleate-2-palmitate glycerol (OPO) and 1-oleate-2-palmitate-3-linoleate glycerol (OPL) using C57BL/6J mice. OPL was associated with higher postprandial plasma total triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C) concentrations, and the ratio of LDL-C to high-density lipoprotein cholesterol (HDL-C) compared to those of OPO (p > 0.05). OPO significantly increased postprandial oleic acid (OA) concentrations compared to OPL over the entire monitoring period (p < 0.05), while OPL significantly elevated linoleic acid (LA) levels compared to OPO (p < 0.05). After 1 month of feeding, the mice in both OPO and OPL groups showed lower final weight, weight gain, and liver TG, LDL-C, and LDL/HDL concentrations compared to the control (soybean oil) group. Lipidomics results showed that OPO increased the biosynthesis of very long-chain fatty acids and decreased the abundance of AcCa (16:1), AcCa (18:2), AcCa (18:1), AcCa (16:0), CarE (16:0), and CarE (16:1) relative to OPL. These lipid metabolites were positively correlated with liver TG, LDL-C, and LDL/HDL levels and negatively related to peroxisome proliferator-activated receptors α (PPARα) and acyl-CoA oxidase (ACOX1) expression. This study showed differences in physiologic functions between OPO and OPL and provided support for the future application of OPL in infant formula.

Circulating microRNAs as novel biomarkers for measuring the potency of ginger extract against cyclophosphamide toxicity in rat renal tissues: molecular and histopathological study.

OBJECTIVE: This study aims to explore underlying molecular variations in the expression of miRNAs in kidney tissues of ginger-treated and non-treated cyclophosphamide (CP)-intoxicated rats. MATERIALS AND METHODS:   A total of 40 adult male Wistar rats were randomly divided into four groups of 10 each: Group I (control: received normal food and water), Group II (received ginger at a dose of 300 mg/kg), Group III (received CP 75 mg/kg, i.p.), and Group IV (received the same dose of CP and ginger extract).  Rats received a single injection of 75 mg/kg CP on days 3, 4, 5, 19, 20, and 21. In CP-intoxicated rats, the treatment with ginger extract at a dose of 300 mg/kg was received by oral gavage starting seven days before CP and continuing throughout the duration of the experiment for four weeks. Molecular variations in the expression of miRNAs, apoptotic genes, histological kidney damage, and abnormal kidney function in control, ginger, and CP-intoxicated rats were identified by using real-time RT-PCR Analysis, immunohistochemical, and colorimetric assays. In addition, HPLC analysis and liquid chromatography spectrophotometry analysis using Diphenyl-1-picrylhydrazyl (DPPH) radical, and Β-Carotene-linoleic acid reagents were applied respectively for in-vitro screening of phytoconstituents and antioxidant activity for ginger extract. RESULTS: The kidney tissues of CP-intoxicated rats displayed an increase in lipid peroxidation marker malonaldehyde (MDA), DNA damage, and fibrosis markers like hyaluronic acid (HA) and hydroxyproline Hypx) with a decrease in the superoxide dismutase (SOD) and total antioxidant capacity (TAC). In addition, molecular expressions of mRNA fibrotic genes such as collagen, type 1, alpha 1 (COL1A1), and α-smooth muscle actin (αSMA). Molecular expressions of levels of B-cell lymphoma 2 (BCl-2) mRNA gene were down-regulated, and the expression of mRNA apoptotic; BCL2 associated X gene (Bax), caspase-3, Bax/BCl-2 ratio genes were significantly up-regulated respectively. Moreover, cellular oxidative genes, erythroid 2-related factor (Nrf2), and heme oxygenase-1 (HO-1) were down-regulated, respectively. The miR-155-5p, miR-34a-5p, miR-21-5p significantly increased while the miR-193b-3p, miR-455-3p, and miR-342-3p significantly decreased. Ginger also increased the expression of Nrf2, HO-1, and BCl-2 genes in the kidneys of rats induced with CP. In addition, active phytoconstituents, particularly 6]]-shogaol and 6]]-gingerol, were significantly identified in ginger extract using HPLC analysis. Antioxidant activity of these active metabolites were shown to be higher against in vitro free radicals (DPPH and Β-Carotene-linoleic acid), suggesting the potential antioxidant and antiapoptotic properties of ginger against CP-toxicity. CONCLUSIONS: Treatment with ginger in rats induced with CP resulted in significant improvement in the expression of certain molecular miRNAs. The kidney tissues of these rats showed a marked decrease in the expression of miR-155-5p, miR-34a-5p, and miR-21-5p, while the levels of miR-193b-3p, miR-455-3p, and miR-342-3p were observed to increase significantly. In conclusion, ginger can protect rats from CP-induced nephrotoxicity.

A gut microbial metabolite of linoleic acid ameliorates liver fibrosis by inhibiting TGF-ß signaling in hepatic stellate cells.

The antidiabetic drug pioglitazone ameliorates insulin resistance by activating the transcription factor PPARγ. In addition to its blood glucose-lowering action, pioglitazone exerts pleiotropic effects including amelioration of nonalcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). The mechanism by which pioglitazone achieves this latter effect has remained unclear, however. We here show that pioglitazone administration increases the amount of linoleic acid (LA) metabolites in adipose tissue of KK-Ay mice. These metabolites are produced by lactic acid bacteria in the gut, and pioglitazone also increased the fraction of Lactobacillus in the gut microbiota. Administration of the LA metabolite HYA (10-hydroxy-cis-12-octadecenoic acid) to C57BL/6 J mice fed a high-fat diet improved liver histology including steatosis, inflammatory cell infiltration, and fibrosis. Gene ontology analysis of RNA-sequencing data for the liver revealed that the top category for genes downregulated by HYA treatment was related to extracellular matrix, and the expression of individual genes related to fibrosis was confirmed to be attenuated by HYA treatment. Mechanistically, HYA suppressed TGF-ß-induced Smad3 phosphorylation and fibrosis-related gene expression in human hepatic stellate cells (LX-2). Our results implicate LA metabolites in the mechanism by which pioglitazone ameliorates liver fibrosis, and they suggest that HYA is a potential therapeutic for NAFLD/NASH.

Replacement of saturated fatty acids with linoleic acid in western diet attenuates atherosclerosis in a mouse model with inducible ablation of hepatic LDL receptor.

Dietary saturate fatty acids (SFAs) have been consistently linked to atherosclerosis and obesity, both of which are characterized by chronic inflammation and impaired lipid metabolism. In comparison, the effects of linoleic acid (LA), the predominant polyunsaturated fatty acid in the Western diet, seem to diverge. Data from human studies suggest a positive association between high dietary intake of LA and the improvement of cardiovascular risk. However, excessive LA intake has been implicated in the development of obesity. Concerns have also been raised on the potential pro-inflammatory properties of LA metabolites. Herein, by utilizing a mouse model with liver-specific Ldlr knockdown, we directly determined the effects of replacing SFAs with LA in a Western diet on the development of obesity and atherosclerosis. Specifically, mice treated with a Ldlr ASO were placed on a Western diet containing either SFA-rich butter (WD-B) or LA-rich corn oil (WD-CO) for 12 weeks. Despite of showing no changes in body weight gain or adiposity, mice on WD-CO exhibited significantly less atherosclerotic lesions compared to those on WD-B diet. Reduced lesion formation in the WD-CO-fed mice corresponded with a reduction of plasma triglyceride and cholesterol content, especially in VLDL and LDL, and ApoB protein levels. Although it increased expression of proinflammatory cytokines TNF-α and IL-6 in the liver, WD-CO did not appear to affect hepatic injury or damage when compared to WD-B. Collectively, our results indicate that replacing SFAs with LA in a Western diet could reduce the development of atherosclerosis independently of obesity.