Expression Of Carnitine Palmitoyltransferase Research Articles

Investigation on the lipid-lowering effect and mechanism by combining turmeric with hawthorn in C57BL/6 obese mice.

Study on the hypolipidemic effect of turmeric combined with hawthorn on C57BL/6 obese mice and its possible mechanism. C57 mice were fed with 60% high-fat diet for 8 weeks to establish an obesity model, and 4 mice were slaughtered to verify whether the modeling was successful. The successful mice were divided into model group (HFD), positive group (high fat feed group [HFD]+simvastatin group [SIM]), turmeric group (HFD+TUR), hawthorn group (HFD+HAW), and para-medicine group (HFD+para-drug group [DOU]) for 4 weeks by gavage intervention. Different intervention groups had certain lipid-lowering effects, and the para-medicine group showed significant differences (p<0.05, p<0.01, p<0.001) in reducing serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, glutamic acid transaminase (ALT), glutamic acid transaminase (AST), and increasing high-density lipoprotein cholesterol. In the para-medicine group, the protein expression of peroxisome proliferator-activated receptor γ, fatty acid synthase, platelet-reactive protein receptor 36, and CCAAT/enhancer binding protein α were significantly downregulated, and the protein expression of carnitine palmitoyl transferase1 and peroxisome proliferator-activated receptor α protein expression (p<0.01, p<0.001), thus suggesting that turmeric and hawthorn are superior to turmeric and hawthorn alone in enhancing lipid metabolism-related mechanisms. Combined effects of turmeric and hawthorn improve lipid metabolism in mice, protect the liver, and improve the protein expression of liver-related genes. This study can lay the theoretical basis for the future association of medicinal food products and the development of related weight loss products.

Complexes of Soluble Dietary Fiber and Polyphenols from Lotus Root Regulate High-Fat Diet-Induced Hyperlipidemia in Mice.

In this paper, complexes of soluble dietary fiber (SDF) and polyphenols (PPs) isolated from lotus roots were prepared (SDF-PPs), as well as physical mixtures (SDF&PPs), which were given to high-fat-diet (HFD)-fed mice. The results demonstrated that SDF-PPs improve lipid levels and reverse liver injury in hyperlipidemic mice. Western blotting and real-time quantitative Polymerase Chain Reaction (RT-qPCR) results showed that SDF-PPs regulated liver lipids by increasing the phosphorylation of Adenine monophosphate activated protein kinase (AMPK), up-regulating the expression of Carnitine palmitoyltransferase1 (CPT1), and down-regulating the expression of Fatty acid synthase (FAS) and 3-hydroxy-3-methyl glutaryl coenzyme A (HMG-CoA), as well as the transcription factor sterol-regulatory element binding protein (SPEBP-1) and its downstream liposynthesis genes. Additionally, the intervention of SDF-PPs could modulate the composition of intestinal gut microbes, inducing an increase in Lachnospiraceae and a decrease in Desulfovibrionaceae and Prevotellaceae in high-fat-diet-fed mice. Thus, the research provides a theoretical basis for the application of lotus root active ingredients in functional foods and ingredients.

Fatty acid oxidation fuels natural killer cell responses against infection and cancer

Natural killer (NK) cells are a vital part of the innate immune system capable of rapidly clearing mutated or infected cells from the body and promoting an immune response. Here, we find that NK cells activated by viral infection or tumor challenge increase uptake of fatty acids and their expression of carnitine palmitoyltransferase I (CPT1A), a critical enzyme for long-chain fatty acid oxidation. Using a mouse model with an NK cell-specific deletion of CPT1A, combined with stable 13C isotope tracing, we observe reduced mitochondrial function and fatty acid-derived aspartate production in CPT1A-deficient NK cells. Furthermore, CPT1A-deficient NK cells show reduced proliferation after viral infection and diminished protection against cancer due to impaired actin cytoskeleton rearrangement. Together, our findings highlight that fatty acid oxidation promotes NK cell metabolic resilience, processes that can be optimized in NK cell-based immunotherapies.

Acyl-Carnitines Exert Positive Effects on Mitochondrial Activity under Oxidative Stress in Mouse Oocytes: A Potential Mechanism Underlying Carnitine Efficacy on PCOS.

Carnitines play a key physiological role in oocyte metabolism and redox homeostasis. In clinical and animal studies, carnitine administration alleviated metabolic and reproductive dysfunction associated with polycystic ovarian syndrome (PCOS). Oxidative stress (OS) at systemic, intraovarian, and intrafollicular levels is one of the main factors involved in the pathogenesis of PCOS. We investigated the ability of different acyl-carnitines to act at the oocyte level by counteracting the effects of OS on carnitine shuttle system and mitochondrial activity in mouse oocytes. Germinal vesicle (GV) oocytes were exposed to hydrogen peroxide and propionyl-l-carnitine (PLC) alone or in association with l-carnitine (LC) and acetyl-l-carnitine (ALC) under different conditions. Expression of carnitine palmitoyltransferase-1 (Cpt1) was monitored by RT-PCR. In in vitro matured oocytes, metaphase II (MII) apparatus was assessed by immunofluorescence. Oocyte mitochondrial respiration was evaluated by Seahorse Cell Mito Stress Test. We found that Cpt1a and Cpt1c isoforms increased under prooxidant conditions. PLC alone significantly improved meiosis completion and oocyte quality with a synergistic effect when combined with LC + ALC. Acyl-carnitines prevented Cpt1c increased expression, modifications of oocyte respiration, and ATP production observed upon OS. Specific effects of PLC on spare respiratory capacity were observed. Therefore, carnitine supplementation modulated the intramitochondrial transfer of fatty acids with positive effects on mitochondrial activity under OS. This knowledge contributes to defining molecular mechanism underlying carnitine efficacy on PCOS.

Dietary Supplementation with 20-Hydroxyecdysone Ameliorates Hepatic Steatosis and Reduces White Adipose Tissue Mass in Ovariectomized Rats Fed a High-Fat, High-Fructose Diet.

Metabolic dysfunction-associated fatty liver disease (MAFLD) is defined as hepatic steatosis in combination with overweight, diabetes, or other metabolic risk factors. MAFLD affects a significant number of the global population and imposes substantial clinical and economic burdens. With no approved pharmacotherapy, current treatment options are limited to diet and exercise. Therefore, the development of medicines for MAFLD treatment or prevention is necessary. 20-Hydroxyecdysone (20E) is a natural steroid found in edible plants and has been shown to improve metabolism and dyslipidemia. Therefore, it may be useful for MAFLD treatment. Here, we aimed to determine how dietary supplementation with 20E affects fat accumulation and lipogenesis in the liver and adipose tissue of ovariectomized rats fed a high-fat, high-fructose diet (OHFFD). We found that 20E reduced hepatic triglyceride content and visceral fat deposition. 20E increased the phosphorylation of AMP-activated protein kinase and acetyl CoA carboxylase while reducing the expression of fatty acid synthase in the liver and adipose tissue. Additionally, 20E increased hepatic expression of carnitine palmitoyltransferase-1 and reduced adipose expression of sterol regulatory element-binding protein-1. In conclusion, 20E demonstrated beneficial effects in rats with OHFFD-induced MAFLD. These findings suggest that 20E may represent a promising option for MAFLD prevention or treatment.

DDIT4 Downregulation by siRNA Approach Increases the Activity of Proteins Regulating Fatty Acid Metabolism upon Aspirin Treatment in Human Breast Cancer Cells

Repositioning of aspirin for a more effective breast cancer (BC) treatment requires identification of predictive biomarkers. However, the molecular mechanism underlying the anticancer activity of aspirin remains fully undefined. Cancer cells enhance de novo fatty acid (FA) synthesis and FA oxidation to maintain a malignant phenotype, and the mechanistic target of rapamycin (mTORC1) is required for lipogenesis. We, therefore, aimed to test if the expression of mTORC1 suppressor DNA damage-inducible transcript (DDIT4) affects the activity of main enzymes in FA metabolism after aspirin treatment. MCF-7 and MDA-MB-468 human BC cell lines were transfected with siRNA to downregulate DDIT4. The expression of carnitine palmitoyltransferase 1 A (CPT1A) and serine 79-phosphorylated acetyl-CoA carboxylase 1 (ACC1) were analyzed by Western Blotting. Aspirin enhanced ACC1 phosphorylation by two-fold in MCF-7 cells and had no effect in MDA-MB-468 cells. Aspirin did not change the expression of CPT1A in either cell line. We have recently reported DDIT4 itself to be upregulated by aspirin. DDIT4 knockdown resulted in 1.5-fold decreased ACC1 phosphorylation (dephosphorylation activates the enzyme), 2-fold increased CPT1A expression in MCF-7 cells, and 2.8-fold reduced phosphorylation of ACC1 following aspirin exposure in MDA-MB-468 cells. Thus, DDIT4 downregulation raised the activity of main lipid metabolism enzymes upon aspirin exposure which is an undesired effect as FA synthesis and oxidation are linked to malignant phenotype. This finding may be clinically relevant as DDIT4 expression has been shown to vary in breast tumors. Our findings justify further, more extensive investigation of the role of DDIT4 in aspirin’s effect on fatty acid metabolism in BC cells.

The combination of metformin with morin alleviates hepatic steatosis via modulating hepatic lipid metabolism, hepatic inflammation, brown adipose tissue thermogenesis, and white adipose tissue browning in high-fat diet-fed mice

AimThe valuable effects of metformin (MET) and morin (MOR) in the improvement of NAFLD have been proposed, nevertheless, their combination impacts were not investigated so far. We determined the therapeutic effects of combined MET and MOR treatment in high-fat diet (HFD)-induced Non-alcoholic fatty liver disease (NAFLD) mice. MethodsC57BL/6 mice were fed on an HFD for 15 weeks. Animals were allotted into various groups and supplemented with MET (230 mg/kg), MOR (100 mg/kg), and MET + MOR (230 mg/kg + 100 mg/kg). Key findingsMET in combination with MOR reduced body and liver weight in HFD-fed mice. A significant decrease in fasting blood glucose and improvement in glucose tolerance was observed in HFD mice treated with MET + MOR. Supplementation with MET + MOR led to a decline in hepatic triglyceride levels and this impact was associated with diminished expression of fatty-acid synthase (FAS) and elevated expression of carnitine palmitoyl transferase 1 (CPT1) and phospho-Acetyl-CoA Carboxylase (p-ACC). Moreover, MET combined with MOR alleviates hepatic inflammation through the polarization of macrophages to the M2 phenotype, decreasing the infiltration of macrophages and lowering the protein level of NF-kB. MET and MOR in combination reduce the size and weight of epididymal white adipose tissue (eWAT), and subcutaneous WAT (sWAT), whereas improves cold tolerance, BAT activity, and mitochondrial biogenesis. Combination therapy results in stimulating brown-like adipocyte (beige) formation in the sWAT of HFD mice. SignificanceThese results suggest that the combination of MET and MOR has a protective effect on hepatic steatosis, which may use as a candidate therapeutic for the improvement of NAFLD.

The impact of variance in carnitine palmitoyltransferase-1 expression on breast cancer prognosis is stratified by clinical and anthropometric factors.

CPT1A is a rate-limiting enzyme in fatty acid oxidation and is upregulated in high-risk breast cancer. Obesity and menopausal status' relationship with breast cancer prognosis is well established, but its connection with fatty acid metabolism is not. We utilized RNA sequencing data in the Xena Functional Genomics Explorer, to explore CPT1A's effect on breast cancer patients' survival probability. Using [18F]-fluorothymidine positron emission tomography-computed tomography images from The Cancer Imaging Archive, we segmented these analyses by obesity and menopausal status. In 1214 patients, higher CPT1A expression is associated with lower breast cancer survivability. We confirmed a previously observed protective relationship between obesity and breast cancer in pre-menopausal patients and supported this data using two-sided Pearson correlations. Taken together, these analyses using open-access databases bolster the potential role of CPT1A-dependent fatty acid metabolism as a pathogenic factor in breast cancer.

Chlorogenic acid improves food allergy through the AMPK/ACC/CPT-1 pathway.

Chlorogenic acid (CGA) is a polyphenol prevalent in daily food and plants. Food allergy (FA) can lead to metabolic disorders of the immune system. The objective of this study was to investigate CGA therapeutic effect on FA and regulatory mechanism through shrimp food allergy in mice models. Here, 24 female BALB/C mice were randomly allocated into the (I) Control group, (II) Food allergy group, (III) Chlorogenic acid low (50 mg/kg), and (IV) high group (200 mg/kg). Enzyme-linked immunosorbent assay revealed that CGA decreased levels of IgE and IgG induced by food allergy significantly. Real-time PCR demonstrated that high-dose chlorogenic acid significantly reduced Acetyl-CoA carboxylase (ACC) mRNA expression and increased Carnitine palmitoyltransferase-1 (CPT-1) mRNA expression. Western blot indicated that CGA promoted a noticeable increase at the levels of AMP-activated protein kinase (AMPK) and ACC phosphorylation, resulting in a significant activation in AMPK and inhibition in ACC, and increased CPT-1 expression. Consequently, CGA improves FA by the regulation of the AMPK/ACC/CPT-1 signaling pathway in the spleen. PRACTICAL APPLICATIONS: Chlorogenic acid is a water-soluble polyphenolic substance that is widely distributed in natural plants that show a variety of pharmacological effects. At present, CGA has been developed as a weigh-reducing tonic in western countries. As one of the most widely found and most easily obtained phenolic acids from food, the diverse physiological effects of CGA (such as anti-inflammatory, antioxidant, metabolic regulation, intestinal microbial regulation, etc.) imply its potential for application in functional foods, food additives, and clinical medicine. However, the basic molecular mechanisms of its effects have not been elucidated. In this study, CGA reduced allergy in a mouse model, likely by interacting with the AMPK/ACC/CPT-1 pathway.

Determination of Metabolomics Profiling in BPA-Induced Impaired Metabolism.

Exposure to bisphenol A (BPA) is unavoidable and it has far-reaching negative effects on living systems. This study aimed to explore the toxic effects of BPA in an experimental animal model through a metabolomics approach that is useful in measuring small molecule perturbations. Beside this, we also examined the ameliorative effects of resveratrol (RSV) against BPA-induced disturbances in experimental mice. This study was conducted for 28 days, and the results showed that BPA indeed induced an impairment in amino acid metabolism, taking place in the mitochondria by significantly (p &lt; 0.05) decreasing the levels of certain amino acids, i.e., taurine, threonine, asparagine, leucine, norleucine, and glutamic acid in the mice plasma. However, the administration of RSV did prove effective against the BPA-induced intoxication and significantly (p &lt; 0.05) restored the level of free amino acids. Lipid metabolites, L-carnitine, sphinganine, phytosphingosine, and lysophosphatidylcholine were also determined in the mice serum. A significant (p &lt; 0.05) decline in glutathione peroxidase (GPx), superoxide dismutase (SOD,) glutathione, and catalase levels and an elevation in malondialdehyde level in the BPA group confirmed the generation of oxidative stress and lipid peroxidation in experimental mice exposed to BPA. The expression of Carnitine palmitoyltransferase I (CPT-I), carnitine palmitoyltransferase II (CPT-II), lecithin-cholesterol acyltransferase (LCAT), carnitine O-octanoyltransferase (CROT), carnitine-acylcarnitine translocase (CACT), and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) genes was significantly upregulated in the liver tissue homogenates of experimental mice exposed to BPA, although RSV regulated the expression of these genes when compared with BPA treated experimental mice. CPT-I, CPT-II, and CACT genes are located in the mitochondria and are involved in the metabolism and transportation of carnitine. Hence, this study confirms that BPA exposure induced oxidative stress, upregulated gene expression, and impaired lipid and amino acid metabolism in experimental mice.

Dietary sodium butyrate supplementation improves fish growth, intestinal microbiota composition, and liver health in largemouth bass (Micropterus salmoides) fed high-fat diets

The present study evaluated the effect of dietary sodium butyrate (NaBT) supplementation on the growth performance, intestinal microbiota composition, and liver health of largemouth bass Micropterus salmoides fed high-fat diets. Four isonitrogenous and isolipid diets were formulated: a high-fat diet and the high-fat diet supplemented by 0.05% NaBT, 0.1% NaBT, or 0.2% NaBT. Each diet was randomly distributed to triplicate tanks (200L) containing 30 fish (initial weight 4.0 ± 0.1 g) per tank. The experimental fish were fed to apparent satiation twice daily for 60 days. The orthogonal polynomial contrasts showed that the weight gain rate (WGR) and specific growth rate (SGR) increased linearly (P < 0.05) with increasing dietary NaBT levels (P < 0.05). No significant differences were found for feed intake (FI), feed conversion ratio (FCR), condition factor (CF), viscerosomatic index (VSI), and hepatosomatic index (HSI). There were no differences in the alpha diversity indices (including Operational Taxonomic Units, Chao index, and Simpson index) of intestinal microbiota between the various dietary groups (P > 0.05). For the intestinal microbiota composition, the proportion of Proteobacteria were linearly and cubically increased, whereas the proportion of Tenericutes and Mesomycoplasma were linearly and cubically decreased with the increase of dietary NaBT levels (P < 0.05). The increasing dietary NaBT levels led to significantly quadratic decrease of alanine aminotransferase (ALT) (P < 0.05), linear and quadratic decrease of aspartate aminotransferase (AST) (P < 0.05), and linear, quadratic, and cubic decrease of diamine oxidase (DAO) (P < 0.05). Hepatic triglyceride (TG) and total cholesterol (TCHO) contents decreased linearly and quadratically with the increase of dietary NaBT levels (P < 0.05). Increasing dietary NaBT levels linearly, quadratically, and cubically decreased the malondialdehyde (MDA) contents (P < 0.05). Total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) activity levels increased linearly with the increasing dietary NaBT levels (P < 0.05). As the dietary NaBT levels gradually increased, the relative expression of carnitine palmitoyl transferase (CPT1) and peroxisome proliferator-activated receptor α (PPARα) increased linearly, quadratically, and cubically (P < 0.05), while the relative expression of sterol regulatory element binding protein 1 (SREBP 1) decreased linearly, quadratically, and cubically (P < 0.05). The relative expression of tumor necrosis factor α (TNF-α) and cysteinyl aspartate specific protease 3 (Caspase 3) decreased linearly and quadratically with the increasing NaBT levels (P < 0.05). Pearson correlation analysis showed that fish growth was closely correlated with microbiota composition, hepatic lipid accumulation, hepatic antioxidant-related parameters, and hepatic gene expression (P < 0.05). These results indicated that NaBT could be used to alleviate the negative influence of high-fat diets on fish growth, intestinal microbiota homeostasis, and liver health.

Chronic agmatine treatment prevents olanzapine-induced obesity and metabolic dysregulation in female rats

Antipsychotic-induced obesity affects millions of people and is a serious health condition worldwide. Olanzapine is the most widely prescribed antipsychotic agent with high obesogenic potential. However, the exact mechanism by which it causes its metabolic dysregulation remains poorly understood. In this study, we investigated the effect of agmatine in olanzapine-induced metabolic derangements in Female Sprague-Dawley rats. Repeated olanzapine administration for 28 days increased body weight while treatment with agmatine from days 15 to 28 prevented the body weight gain induced by olanzapine without any alteration in food intake. Repeated agmatine treatment decreased the elevated feeding efficiency and adiposity index, as well as improved dysregulated lipid metabolism induced by olanzapine. Increased activity of fatty acid synthase (FAS) and decreased expression of carnitine palmitoyl transferase-1 (CPT-1) were detected in chronic olanzapine-treated rats. Although agmatine treatment did not alter FAS activity, it increased CPT-1 activity. It is possible that the inhibitory effect of agmatine on weight gain and adiposity might be associated with increased mitochondrial fatty acid oxidation and energy expenditure in olanzapine-treated rats. We suggest that agmatine can be explored for the prevention of obesity complications associated with chronic antipsychotic treatment.

Effects of dietary lysolecithin on growth performance, serum biochemical indexes, antioxidant capacity, lipid metabolism and inflammation-related genes expression of juvenile large yellow croaker (Larimichthys crocea)

A 70-day feeding trial was conducted to investigate effects of dietary lysolecithin on growth performance, serum biochemical indexes, antioxidant capacity, lipid metabolism and inflammation-related genes expression of juvenile large yellow croaker (Larimichthys crocea) with initial weight of 6.04 ± 0.08 g. A formulated diet containing approximately 42% crude protein and 12.5% crude lipid was used as the control diet (CON). The other three experimental diets were formulated with supplementation of 0.2%, 0.4% and 0.6% lysolecithin based on the control diet, respectively. Results showed that weight gain rate (WGR) and specific growth rate (SGR) significantly increased in fish fed diets with lysolecithin compared with those in the control diet (P < 0.05). Fish fed diets with 0.4% and 0.6% lysolecithin had notably higher lipid content in muscle than that in the control diet (P < 0.05). When fish were fed diets with lysolecithin, serum high-density lipoprotein cholesterol (HDL-c) content was notably higher than that in the control diet (P < 0.05), while fish fed the diet with 0.6% lysolecithin had a significant lower serum low-density lipoprotein cholesterol (LDL-c) content than that in the control diet (P < 0.05). Meanwhile, serum aspartate transaminase (AST) and alanine transaminase (ALT) activities in fish fed diets with lysolecithin were remarkably lower than those in the control diet (P < 0.05). With the increase of dietary lysolecithin from 0.2% to 0.6%, mRNA expression of stearoyl-coenzyme A desaturase 1 (scd1), diacylglycerol acyltransferase 2 (dgat2) and sterol-regulatory element binding protein 1 (srebp1) showed decreasing trends. Furthermore, mRNA expression of carnitine palmitoyl transferase 1 (cpt1) and lipoprotein lipase (lpl) among each dietary lysolecithin treatment were significantly higher than those in the control diet (P < 0.05). In terms of inflammation, mRNA expression of tumor necrosis factor α (tnf-α) and interleukin-1 β (il-1β) were significantly down-regulated in fish fed diets with lysolecithin compared with those in the control diet (P < 0.05), while the mRNA expression of interleukin-10 (il-10) was significantly higher than that in the control diet (P < 0.05). In conclusion, dietary lysolecithin could promote the growth performance, improve hepatic lipid metabolism and regulate inflammation response in juvenile large yellow croaker, and the optimal supplement level of lysolecithin was approximately 0.4% in this study.

Effects of Acute Hypoxic Stress on Physiological and Hepatic Metabolic Responses of Triploid Rainbow Trout (Oncorhynchus mykiss).

This experiment simulated the hypoxic environment caused by actual production operations in fish farming (i.e., catching, gathering, transferring, and weighting) to study the effects of acute hypoxic conditions on the physiological and metabolic responses of triploid rainbow trout (O. mykiss). Two groups of fish weighting 590 g were sampled in the normoxia group (dissolved oxygen above 7 mg/L) and hypoxia group (dissolved oxygen ranged from 2 to 5 mg/L for 10 min). The results showed that 1) regarding stress response, hypoxia increased plasma levels of cortisol, heat shock protein 70 (HSP-70), lysozyme, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatine phosphokinase (CPK); induced the expression of hepatic genes encoding nuclear factor erythroid 2 related factor 2 (Nrf2), interferon γ (IFN-γ) and interleukin-1β (IL-1β). 2) Regarding metabolism response, hypoxia increased plasma levels of globulin (GLOB), glucose (GLU), triglyceride (TG) and lactate dehydrogenase (LDH); upregulated the hepatic gene expression of phosphoenolpyruvate carboxykinase, (PEPCK), pyruvate dehydrogenase kinase (PDK1), acetyl-CoA carboxylase (ACC) and acetyl-CoA oxidase (ACO); downregulated the hepatic gene expression of carnitine palmitoyl transferase 1 (CPT1); and unchanged the expression of hepatic genes in glycolysis and autophagy. 3) In response to hypoxia-inducible factors (HIFs), the hepatic HIF-2α gene was activated in the hypoxia group, but HIF-1α gene expression remained unchanged. Thus, during acute hypoxic stress, triploid rainbow trout were in a defensive state, with an enhanced immune response and altered antioxidant status. Additionally, the hepatic mitochondrial oxidation of glucose- and lipid-derived carbon in trout was suppressed, and hepatic gluconeogenesis and lipid synthesis were activated, which might be regulated by the HIF-2α pathway.

Tetrandrine, an immunosuppressive alkaloid isolated from Steohania tetrandra S. Moore, induces the generation of Treg cells through enhancing fatty acid oxidation.

Our previous studies have demonstrated that tetrandrine can induce the generation of regulatory T (Treg) cells in vitro and in vivo. But, the underlying mechanism of tetrandrine remains obscure. Naïve CD4+ T cells are isolated from the mesenteric lymph nodes of mice for the differentiation of Treg cells. Flow cytometry is used to detect the frequencies of Treg cells. Non-targeted metabolomics analysis based on UHPLC-QTOF/MS is performed to assess the intracellular metabolic profiles. ChIP-PCR analysis is conducted to detect the level of H3K27ac at Foxp3 promoter and CNS regions. Tetrandrine treatment alters the metabolic profile of Treg cells, and pathway enrichment of differential metabolites mainly involves fatty acid oxidation (FAO). Tetrandrine promotes the mRNA expression of carnitine palmitoyl transferase-1, and increases the level of acetyl coenzyme A (acetyl-CoA) and the intracellular oxygen consumption rate. Either CPT1 inhibitor (etomoxir) or siRNA markedly diminishes the promotion of tetrandrine on Treg cell differentiation. Furthermore, tetrandrine enhances the acetylation of H3K27 in the promoter and CNS1 regions of Foxp3 through the acetyl-CoA derived from FAO. In the mice with collagen-induced arthritis, tetrandrine also induces Treg cell generation through FAO pathway. In addition, tetrandrine enhances the immunosuppressive function of Treg cells both in vitro and in vivo. The findings indicate that tetrandrine promotes Treg cell differentiation by enhancing FAO-mediated Foxp3 acetylation, and the CPT1-mediated FAO can serve as the target for the discovery of novel inducers of Treg cell generation.

Glucocorticoid receptor modulates myeloid-derived suppressor cell function via mitochondrial metabolism in immune thrombocytopenia.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells and natural inhibitors of adaptive immunity. Intracellular metabolic changes in MDSCs exert a direct immunological influence on their suppressive activity. Our previous study demonstrated that high-dose dexamethasone (HD-DXM) corrected the functional impairment of MDSCs in immune thrombocytopenia (ITP); however, the MDSC population was not restored in nonresponders, and the mechanism remained unclear. In this study, altered mitochondrial physiology and reduced mitochondrial gene transcription were detected in MDSCs from HD-DXM nonresponders, accompanied by decreased levels of carnitine palmitoyltransferase-1 (CPT-1), a rate-limiting enzyme in fatty acid oxidation (FAO). Blockade of FAO with a CPT-1 inhibitor abolished the immunosuppressive function of MDSCs in HD-DXM responders. We also report that MDSCs from ITP patients had lower expression of the glucocorticoid receptor (GR), which can translocate into mitochondria to regulate the transcription of mitochondrial DNA (mtDNA) as well as the level of oxidative phosphorylation. It was confirmed that the expression of CPT-1 and mtDNA-encoded genes was downregulated in GR-siRNA-treated murine MDSCs. Finally, by establishing murine models of active and passive ITP via adoptive transfer of DXM-modulated MDSCs, we confirmed that GR-silenced MDSCs failed to alleviate thrombocytopenia in mice with ITP. In conclusion, our study indicated that impaired aerobic metabolism in MDSCs participates in the pathogenesis of glucocorticoid resistance in ITP and that intact control of MDSC metabolism by GR contributes to the homeostatic regulation of immunosuppressive cell function.

Spiraea prunifolia leaves extract inhibits adipogenesis and lipogenesis by promoting β-oxidation in high fat diet-induced obese mice

Spiraea prunifolia has been used in Korean traditional medicine to treat malaria, fever, and emetic conditions. Previous investigation reported that several parts of Spiraea prunifolia show various functional effects. However, the effect of Spiraea prunifolia leaves extract (SPE) on anti-obesity remains unclear. Therefore, we used a high-fat diet (HFD)-induced obese mouse model in this study to investigate the effects of SPE on adipogenesis, lipogenesis, and β-oxidation. Oral administration of SPE in HFD-induced obese mice considerably reduced body weight, serum levels such as total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol, adipose tissue weight, and adipocyte cell size. Moreover, SPE significantly decreased protein expression levels of adipogenesis and lipogenesis related genes such as CCAAT/enhancer binding protein α, peroxisome proliferator-activated receptor γ, adipocyte protein 2, acetyl-CoA carboxylase, and fatty acid synthase in epididymal adipose tissues. SPE treatment induced the protein expression of carnitine palmitoyl transferase-1, which might have promoted phosphorylated AMP-activated protein kinase-medicated β-oxidation. The present study reveals an anti-adipogenic, anti-lipogenic, β-oxidation effects of SPE in vivo and represents AMP-activated protein kinase signaling as targets for SPE.

Treatment of preadipocytes with fish oil, mixed oil, or soybean oil-based lipid emulsions have differential effects on the regulation of lipogenic and lipolytic genes in mature 3T3-L1 adipocytes

The key adipose tissue characteristics are established during early development, where lipids play an essential role. Lipid emulsions used in total parenteral nutrition have different omega-(n) 6 to n-3 fatty acid ratios. A lower n-6:n-3 fatty acid decreases lipid accumulation; however, the effects of lipid emulsions with different n-6 to n-3 fatty acid ratios on the programming of preadipocytes to affect lipid accumulation in mature adipocytes is not known. This study compared the effects of Fish oil (FO), Mixed oil (MO), and Soybean oil (SO) based lipid emulsion on genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation in 3T3-L1 adipocytes. Preadipocytes were treated with specific lipid emulsions and then differentiated to mature adipocytes in the absence of lipid emulsions. In a separate experiment, mature 3T3-L1 adipocytes were treated with lipid emulsions to investigate the effects on genes involved in lipolysis. Fatty acid composition, triacylglycerol levels, and the mRNA expression of genes involved in adipogenesis, lipogenesis, lipolysis, and β-oxidation were measured. Preadipocytes and mature adipocytes treated with FO showed higher incorporation of n-3 polyunsaturated fatty acids, lower triacylglycerol levels, and decreased mRNA expression of adipogenic and lipogenic genes, followed by MO and SO. FO and MO increased the mRNA expression of carnitine palmitoyltransferase-1, while FO decreased the mRNA expression of lipolytic genes compared to untreated cells. Our findings suggest that FO programs preadipocytes to prevent adipose tissue dysfunction in mature adipocytes; the effects of FO-based lipid emulsion were followed by MO and SO.

Pink Lotus Essential Oil and Alleviates on Free Fatty Acid Induced Steatosis in HepG2 Cells via PI3K/Akt and NF-κB Pathways.

Pink lotus essential oil (PLEO) is the volatile components extracted from lotus flowers and there are few relevant research. The purpose of this study was to observe the effect of PLEO on NAFLD in vitro model and its possible mechanism. The ingredients of PLEO were determined by gas chromatography-mass spectrometry (GS-MS) and its lipid-lowering and hepatoprotective activities were investigated. HepG2 cells were treated with free fatty acid (FFA) to establish a cell model of NAFLD. Cell viability was evaluated by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. Total cholesterol (TC), triglyceride (TG), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were determined by Enzyme-Linked Immune Sorbent Assay (ELISA). Oil red O staining was performed to observe the lipid accumulation in the HepG2 cells. Lipid metabolism enzymes including fatty acid synthase (FAS), acetyl-coA carboxylase (ACC), stearoyl-CoA desaturase 1 (SCD-1), and carnitine palmitoyltransferase-1 (CPT-1), insulin signaling pathways including phosphatidylinositol 3 kinase (PI3K) and protein kinase B Akt, inflammatory signaling pathways such as nuclear factor kappa-B (NF-κB), were determined by Western blotting. There were 46 components determined in PLEO with many terpenoids compounds. PLEO decreased TC and TG contents in the FFA-treated HepG2 cells. Furthermore, PLEO inhibited TNF-α, IL-6 and IL-1β excretion, decreased NF-κB, FAS, ACC and SCD-1 while increased phosphorylation of NF-κB, PI3K, Akt, and CPT-1 expression. It is the first time to reveal that PLEO alleviates FFA-induced steatosis in HepG2 cells by regulating lipid metabolism, inhibiting inflammatory response, and improving insulin sensitivity.

Vascular endothelial growth factor B exerts lipid-lowering effect by activating AMPK via VEGFR1

As an ambiguous member of vascular endothelial growth factor family, VEGF-B has long been poorly understood in its function. Recent researches showed VEGF-B isoforms exerted their metabolic effect through indirectly activating the VEGF-A/VEGFR2 pathway. Here, we report the lipid-lowing effect of VEGF-B via VEGFR1. We investigated the effect of VEGF-B on lipid metabolism in vivo and in vitro approaches. Treatment of mice with VEGF-B recombinant protein repressed HFD-induced body weight gain. This treatment also alleviated obesity associated hyperlipidemia and fatty liver disease. In the muscle and liver of VEGF-B-treated HFD mice were observed increased protein expression of carnitine palmitoyltransferase-1 (CPT-1) and the phosphorylation of ACC and AMP-activated protein kinase (AMPK). This effect was confirmed in HepG2 cells incubated with VEFG-B in which the increased AMPK activation and CPT-1 expression occurs due to activation of Calcium/calmodulin-dependent Protein Kinase β (CaMKKβ) by VEFG-B. VEGF-B increased expression of key genes responsible for lipid oxidation while reducing those for fatty acid synthesis in vivo and in vitro. In addition, the selective inhibitor of VEGFR1 blocked the lipid clearance effect of VEGF-B in HepG2. Our study unraveled unknown role of VEGF-B/VEGFR1 signaling in regulating lipid metabolism. Furthermore, our findings indicate that VEGF-B may have beneficial effects for the treatment of dyslipidemia.