Low expression of fatty acid oxidation related gene ACADM indicates poor prognosis of renal clear cell carcinoma and is related to tumor immune infltration

This research aims to identify the key fatty acid beta-oxidation(FAO)genes that are altered in kidney renal clear cell carcinoma(KIRC)and to analyze the role of these genes in KIRC The Gene Expression Omnibus(GEO)and FAO datasets were used to identify these key genes.Wilcoxon rank sum test was used to assess the levels of acyl-CoA dehydrogenase medium chain(ACADM)between KIRC and non cancer samples.The logistic regression and Wilcoxon rank sum test were used to explore the association between ACADM and clinical features.The diagnostic performance of ACADM for KIRC was asessed using a diagnostic receiver operating ch aracteristic(ROC)curve.The co-expressed genes of ACADM were identifed in LinkedOmics database,and their function and pathway enrichment were analyzed.The correlation between ACADM expression level and immune infitration was analyzed by Gene Set Variation Analysis(GSVA)method Additionally,the proliferation,migration,and invasion abilities of KIRC cells were assessed after overexpressing ACADM.Following differential analysis and intersection,we identifed six hub genes,induding ACADM.We found that the expression level of ACADM was decreased in KIRC tissues and had a better diagnostic efect(AUC=0.916).Survival analysis suggested that patients with decreased ACADM expression had a worse prognosis.According to correlation analysis,a variety of dinical features were associated with the expression level of ACADML By analyzing the infiltration level of immune cells,we found that ACADM may be related to the enrichment of immune cells.Finally,ACADM overexpression inhibited proliferation,migration,and invasion of KIRC cells.In conclusion,our findings suggest that reduced ACADM expression in KIRC patients is indicative of poor prognosis.These results imply that ACADM may be a diagnostic and prognostic marker for individuals with KIRC,offering a reference for dinicians in diagnosis and treatment.

Mathematical Modeling of the Oxidation of Polyunsaturated Fatty Acids in Emulsions with Stirring and Limited Oxygen Compensation

The oxidation of polyunsaturated fatty acids （PUFA） in emulsion with stirring and limited oxygen compensation was studied. A mathematical model of diffusion-oxidation was developed considering the mass transfer resistance of a gas-liquid boundary, the resistance of the boundary layer from the emulsifier membrane, and the autocatalytic-type autoxidation reaction of PUFA. The dynamic mass transfer coefficient of the emulsifier membrane, k0, was introduced. The model was verified by comparing the predictions of the model with the experi- mental data. The results indicated that the model was in good agreement with the oxygen diffusion and linoleic acid oxidation in the emulsion, and showed good applicability in the prediction of the effect of the emulsifier type on the oxidation of PUFA in the emulsion. It indicated that the oxidation of PUFA in emulsions, with stirring and limited oxygen compensation from the atmosphere, was controlled mostly by mass transfer resistance from the emulsifier membrane.

Betaine affects muscle lipid metabolism via regulating the fatty acid uptake and oxidation in finishing pig

Background： Betaine affects fat metabolism in animals, but the specific mechanism is still not clear. The purpose of this study was to investigate possible mechanisms of betaine in altering lipid metabolism in muscle tissue in finishing pigs.Methods： A total of 120 crossbred gilts（Landrace × Yorkshire × Duroc） with an average initial body weight of 70.1 kg were randomly allotted to three dietary treatments. The treatments included a corn–soybean meal basal diet supplemented with 0, 1250 or 2500 mg/kg betaine. The feeding experiment lasted 42 d.Results： Betaine addition to the diet significantly increased the concentration of free fatty acids（FFA） in muscle（P 〈 0.05）. Furthermore, the levels of serum cholesterol and high-density lipoprotein cholesterol were decreased（P 〈 0.05） and total cholesterol content was increased in muscle（P 〈 0.05） of betaine fed pigs. Experiments on genes involved in fatty acid transport showed that betaine increased expression of lipoprotein lipase（LPL）, fatty acid translocase/cluster of differentiation（FAT/CD36）, fatty acid binding protein（FABP3） and fatty acid transport protein（FATP1）（P 〈 0.05）. The abundance of fatty acid transport protein and fatty acid binding protein were also increased by betaine（P 〈 0.05）. As for the key factors involved in fatty acid oxidation, although betaine supplementation didn＇t affect the level of carnitine and malonyl-CoA, betaine increased mR NA and protein abundance of carnitine palmitransferase-1（CPT1）and phosphorylated-AMPK（P 〈 0.05）.Conclusions： The results suggested that betaine may promoted muscle fatty acid uptake via up-regulating the genes related to fatty acid transporter including FAT/CD36, FATP1 and FABP3. On the other hand, betaine activated AMPK and up-regulated genes related to fatty acid oxidation including PPARα and CPT1. The underlying mechanism regulating fatty acid metabolism in pigs supplemented with betaine is associated with the up-regulation of genes involved in fatty acid transport and fatty acid oxidation.

Effect of dietary soybean oil and antioxidants on fatty acids and volatile compounds of tail subcutaneous and perirenal fat tissues in fattening lambs

Background： Fat is the primary source of the volatiles that determine the characteristic flavors of animal products.Because unsaturated fatty acids（UFAs） contribute to changes in flavor as a result of the oxidation process, a feeding trial was performed to investigate the effects of dietary soybean oil or antioxidants on the fatty acid and volatile profiles of the tail subcutaneous（SF） and perirenal fat tissues（PF） of fattening lambs. Thirty-six Huzhou lambs were assigned to four dietary treatments in a randomized block design. The lambs＇ diets were supplemented with soybean oil（0 or 3 % of DM） or antioxidants（0 or 0.025 % of DM）.Results： Neither soybean oil nor antioxidant supplementation had an effect on lamb growth（P 〉 0.05）. In regard to tail SF, soybean oil supplementation increased the 18：2n6t（P 〈 0.05） and the total amount of volatile acids,whereas antioxidant supplementation increased the content of C18：2n6c and C18：3n3（P 〈 0.05） but had no effect on the volatiles profile. In regard to PF, dietary soybean oil supplementation increased the C18：0 content（P 〈 0.01）;decreased the C18：1（P = 0.01）, C22：1 n9（P 〈 0.01） and total UFA（P = 0.03） contents; and tended to decrease the E-2-octenal（P = 0.08）, E, E-2, 4-decadienal（P = 0.10）, 2-undecenal（P = 0.14） and ethyl 9-decenoate（P = 0.10） contents.Antioxidant supplementation did not affect either the fatty acid content or the volatiles profile in the PF.Conclusions： Tail SF and PF responded to dietary soybean oil and antioxidant supplementation in different ways. For SF, both soybean oil and antioxidant supplementation increased the levels of unsaturated fatty acids but triggered only a slight change in volatiles. For PF, soybean oil supplementation decreased the levels of unsaturated fatty acids and oxidative volatiles, but supplementation with antioxidants had little effect on PF fatty acids and the volatiles profile.

Transplacental induction of fatty acid oxidation in term fetal pigs by the peroxisome proliferator-activated receptor alpha agonist clofibrate

Background： To induce peroxisomal proliferator-activated receptor α（PPARα） expression and increase milk fat utilization in pigs at birth, the effect of maternal feeding of the PPARα agonist, clofibrate（2-（4-chlorophenoxy）-2-methyl-propanoic acid, ethyl ester）, on fatty acid oxidation was examined at ful-term delivery（0 h） and 24 h after delivery in this study.Each group of pigs（n = 10） was delivered from pregnant sows fed a commercial diet with or without 0.8% clofibrate for the last 7 d of gestation. Blood samples were col ected from the utero-ovarian artery of the sows and the umbilical cords of the pigs as they were removed from the sows by C-section on day 113 of gestation.Results： HPLC analysis identified that clofibric acid was present in the plasma of the clofibrate-fed sow（~4.2 μg/m L）and its offspring（~1.5 μg/m L）. Furthermore, the maternal-fed clofibrate had no impact on the liver weight of the pigs at 0 h and 24 h, but hepatic fatty acid oxidation examined in fresh homogenates showed that clofibrate increased（P 〈 0.01）^14C-accumulation in CO2 and acid soluble products 2.9-fold from [1-^14C]-oleic acid and 1.6-fold from[1-^14C]-lignoceric acid respectively. Correspondingly, clofibrate increased fetal hepatic carnitine palmitoyltransferase（CPT）and acyl-Co A oxidase（ACO） activities by 36% and 42% over controls（P 〈 0.036）. The m RNA abundance of CPT I was 20-fold higher in pigs exposed to clofibrate（P 〈 0.0001） but no differences were detected for ACO and PPARα m RNA between the two groups.Conclusion： These data demonstrate that dietary clofibrate is absorbed by the sow, crosses the placental membrane, and enters fetal circulation to induce hepatic fatty acid oxidation by increasing the CPT and ACO activities of the newborn.

Glycolytic and fatty acid oxidation genes affect the treatment and prognosis of liver cancer

BACKGROUND Metabolic reprogramming is a feature of tumour cells and is essential to support their rapid proliferation.The glycolytic activity of liver cancer cells is significantly higher than that of normal liver cells,and the rapidly proliferating tumour cells are powered by aerobic glycolysis.Lipid metabolism reprogramming enables tumour cells to meet their needs for highly proliferative growth and is an important driving force for the development of hepatocellular carcinoma(HCC).AIM To explore the influence of different metabolic subtypes of HCC and analyse their significance in guiding prognosis and treatment based on the molecular mechanism of glycolysis and fatty acid oxidation(FAO).METHODS By downloading related data from public databases including the Cancer Genome Atlas(TCGA),the Molecular Signatures Database,and International Cancer Genome Consortium,we utilised unsupervised consensus clustering to divide TCGA Liver Hepatocellular Carcinoma samples into four metabolic subgroups and compared single nucleotide polymorphism,copy number variation,tumour microenvironment,and Genomics of Drug Sensitivity in Cancer and Tumour Immune Dysfunction and Exclusion between different metabolites.The differences and causes of survival and the clinical characteristics between them were analysed,and a prognostic model was established based on glycolysis and FAO genes.Combined with the clinical features,a Norman diagram was created to compare the pros and cons of each model.RESULTS In the four metabolic subgroups,with the increase in glycolytic expression,the median survival of patients showed the worst results,while FAO showed the best.When comparing the follow-up analysis of each group,we considered that the differences between them might be related to reactive oxygen species,somatic copy number variation of key genes,and immune microenvironment.It was also found that the FAO group and the low-risk group had better efficacy and response to immune checkpoint blockade treatment and anti-tumour drugs.CONCLUSION There are obvious differences in genes,chromosomes,and clinical characteristics between metabolic subgroups.The establishment of a prognostic model could predict patient prognosis and guide clinical treatment.

Metabolic reprogramming of the inflammatory response in the nervous system:the crossover between inflammation and metabolism

Metabolism is a fundamental process by which biochemicals are broken down to produce energy(catabolism) or used to build macromolecules(anabolism). Metabolism has received renewed attention as a mechanism that generates molecules that modulate multiple cellular responses. This was first identified in cancer cells as the Warburg effect, but it is also present in immunocompetent cells. Studies have revealed a bidirectional influence of cellular metabolism and immune cell function, highlighting the significance of metabolic reprogramming in immune cell activation and effector functions. Metabolic processes such as glycolysis, oxidative phosphorylation, and fatty acid oxidation have been shown to undergo dynamic changes during immune cell response, facilitating the energetic and biosynthetic demands. This review aims to provide a better understanding of the metabolic reprogramming that occurs in different immune cells upon activation, with a special focus on central nervous system disorders. Understanding the metabolic changes of the immune response not only provides insights into the fundamental mechanisms that regulate immune cell function but also opens new approaches for therapeutic strategies aimed at manipulating the immune system.

Meldonium-induced steatosis is associated with increased delta 6 desaturation and reduced elongation of n-6 polyunsaturated fatty acids

Background and objective Metabolic associated fatty liver disease(MAFLD)is associated with abnormal lipid metabolism.Mitochondrial dysfunction is considered an important factor in the onset of MAFLD,whereas altered fatty acid composition has been linked to the severity of the disease.Tetradecylthioacetic acid(TTA),shown to induce mitochondrial proliferation and alter the fatty acid composition,was used to delay the accumulation of hepatic triacylglycerol.This study aimed to evaluate how impaired mitochondrial fatty acid beta-oxidation affects fatty acid composition by incorporating meldonium into a high-carbohydrate diet.Methods C57BL/6 mice(n=40)were fed high-carbohydrate diets supplemented with meldonium,TTA,or a combination of meldonium and TTA for 21 days.Lipid levels were determined in liver samples,and fatty acid composition was measured in both liver and plasma samples.Additionally,desaturase and elongase activities were estimated.The hepatic activities and gene expression levels of enzymes involved in fatty acid metabolism were measured in liver samples,whereas carnitines,their precursors,and acylcarnitines were measured in plasma samples.Results The meldonium-induced depletion of L-carnitine and mitochondrial fatty acid oxidation was confirmed by reduced plasma levels of L-carnitine and acylcarnitines.Principal component analyses of the hepatic fatty acid composition revealed clustering dependent on meldonium and TTA.The meldonium-induced increase in hepatic triacylglycerol levels correlated negatively with estimated activities of elongases and was associated with higher estimated activities of delta-6 desaturase(D6D;C18:4n-3/C18:3n-3 and C18:3n-6/C18:2n-6),and increased circulating levels of C18:4n-3 and C18:3n-6(gamma-linolenic acid).TTA mitigated meldonium-induced triacylglycerol levels by 80%and attenuated the estimated D6D activities,and elongation of n-6 polyunsaturated fatty acids(PUFAs).TTA also attenuated the meldonium-mediated reduction of C24:1n-9(nervonic acid),possibly by stimulating Elovl5 and increased elongation of erucic acid(C22:1n-9)to nervonic acid.The hepatic levels of nervonic acid and the estimated activity of n-6 PUFA elongation correlated negatively with the hepatic triacylglycerol levels,while the estimated activities of D6D correlated positively.Conclusion Circulating levels of gamma-linolenic acid,along with reduced estimated elongation of n-6 PUFAs and D6D desaturation activities,were associated with hepatic triacylglycerol levels.

Nonalcoholic fatty liver disease and mitochondrial dysfunction

Nonalcoholic fatty liver disease (NAFLD) includes hepatic steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, and cirrhosis. NAFLD is the most common liver disorder in the United States and worldwide. Due to the rapid rise of the metabolic syndrome, the prevalence of NAFLD has recently dramatically increased and will continue to increase. NAFLD has also the potential to progress to hepatocellular carcinoma (HCC) or liver failure. NAFLD is strongly linked to caloric overconsumption, physical inactivity, insulin resistance and genetic factors. Although significant progress in understanding the pathogenesis of NAFLD has been achieved in years, the primary metabolic abnormalities leading to lipid accumulation within hepatocytes has remained poorly understood. Mitochondria are critical metabolic organelles serving as "cellular power plants". Accumulating evidence indicate that hepatic mitochondrial dysfunction is crucial to the pathogenesis of NAFLD. This review is focused on the significant role of mitochondria in the development of NAFLD.

Indole alkaloids of Alstonia scholaris(L.)R.Br.alleviated nonalcoholic fatty liver disease in mice fed with high-fat diet

Alstonia scholaris(L.)R.Br(Apocynaceae)is a well-documented medicinal plant for treating respiratory diseases,liver diseases and diabetes traditionally.The current study aimed to investigate the effects of TA on non-alcoholic fatty liver disease(NAFLD).A NAFLD model was established using mice fed a high-fat diet(HFD)and administered with TA(7.5,15 and 30 mg/kg)orally for 6 weeks.The biochemical parameters,expressions of lipid metabolism-related genes or proteins were analyzed.Furthermore,histopathological examinations were evaluated with Hematoxylin-Eosin and MASSON staining.TA treatment significantly decreased the bodyweight of HFD mice.The concentrations of low-density lipoprotein(LDL),triglyceride(TG),aspartate aminotransferase(AST)and alanine aminotransferase(ALT)were also decreased significantly in TA-treated mice group,accompanied by an increase in high-density lipoprotein(HDL).Furthermore,TA alleviated hepatic steatosis injury and lipid droplet accumulation of liver tissues.The liver mRNA levels involved in hepatic lipid synthesis such as sterol regulatory element-binding protein 1C(SREBP-1C),regulators of liver X receptorα(LXRα),peroxisome proliferator activated receptor(PPAR)γ,acetyl-CoA carboxylase(ACC1)and stearyl coenzyme A dehydrogenase-1(SCD1),were markedly decreased,while the expressions involved in the regulation of fatty acid oxidation,PPARα,carnitine palmitoyl transterase 1(CPT1A),and acyl coenzyme A oxidase 1(ACOX1)were increased in TA-treated mice.TA might attenuate NAFLD by regulating hepatic lipogenesis and fatty acid oxidation.

Characteristics of glucose and lipid metabolism and the interaction between gut microbiota and colonic mucosal immunity in pigs during cold exposure

Background Cold regions have long autumn and winter seasons and low ambient temperatures.When pigs are unable to adjust to the cold,oxidative damage and inflammation may develop.However,the differences between cold and non-cold adaptation regarding glucose and lipid metabolism,gut microbiota and colonic mucosal immunological features in pigs are unknown.This study revealed the glucose and lipid metabolic responses and the dual role of gut microbiota in pigs during cold and non-cold adaptation.Moreover,the regulatory effects of dietary glucose supplements on glucose and lipid metabolism and the colonic mucosal barrier were evaluated in cold-exposed pigs.Results Cold and non-cold-adapted models were established by Min and Yorkshire pigs.Our results exhibited that cold exposure induced glucose overconsumption in non-cold-adapted pig models(Yorkshire pigs),decreasing plasma glucose concentrations.In this case,cold exposure enhanced the ATGL and CPT-1αexpression to promote liver lipolysis and fatty acid oxidation.Meanwhile,the two probiotics(Collinsella and Bifidobacterium)depletion and the enrichment of two pathogens(Sutterella and Escherichia-Shigella)in colonic microbiota are not conducive to colonic mucosal immunity.However,glucagon-mediated hepatic glycogenolysis in cold-adapted pig models(Min pigs)maintained the stability of glucose homeostasis during cold exposure.It contributed to the gut microbiota(including the enrichment of the Rikenellaceae RC9 gut group,[Eubacterium]coprostanoligenes group and WCHB1-41)that favored cold-adapted metabolism.Conclusions The results of both models indicate that the gut microbiota during cold adaptation contributes to the protection of the colonic mucosa.During non-cold adaptation,cold-induced glucose overconsumption promotes thermogenesis through lipolysis,but interferes with the gut microbiome and colonic mucosal immunity.Furthermore,glucagon-mediated hepatic glycogenolysis contributes to glucose homeostasis during cold exposure.

Effects of medium chain triglycerides on hepatic fatty acid oxidation in clofibrate-fed newborn piglets

To investigate whether increasing tricarboxylic acid(TCA)cycle activity and ketogenic capacity would augment fatty acid(FA)oxidation induced by the peroxisome proliferator-activated receptor-alpha(PPARα)agonist clofibrate,suckling newborn piglets(n=54)were assigned to 8 groups following a 2(±clofibrate)×4(glycerol succinate[SUC],triglycerides of 2-methylpentanoic acid[T2M],valeric acid[TC5]and hexanoic acid[TC6])factorial design.Each group was fed an isocaloric milk formula containing either 0%or 0.35%clofibrate(wt/wt,dry matter basis)with 5%SUC,T2M,TC5 or TC6 for 5 d.Another 6 pigs served as newborn controls.Fatty acid oxidation was examined in fresh homogenates of liver collected on d 6 using[1-^(14)C]palmitic acid(1 mM)as a substrate(0.265μCi/μmol).Measurements were performed in the absence or presence of L-carnitine(1 mM)or inhibitors of 3-hydroxy-3-methylglutaryl-CoA synthase(L659699,1.6μM)or acetoacetate-CoA deacylase(iodoacetamide,50μM).Without clofibrate stimulation,^(14)C accumulation in CO_(2) was higher from piglets fed diets containing T2M and TC5 than SUC,but similar to those fed TC6.Under clofibrate stimulation,accumulation also was higher in homogenates from piglets fed TC5 than all other dietary treatments.Interactions between clofibrate and carnitine or the inhibitors were observed(P=0.0004)for acid soluble products(ASP).In vitro addition of carnitine increased^(14)C-ASP(P<0.0001)above all other treatments,regardless of clofibrate treatment.The percentage of^(14)C in CO_(2) was higher(P=0.0023)in TC5 than in the control group.From these results we suggest that dietary supplementation of anaplerotic and ketogenic FA could impact FA oxidation and modify the metabolism of acetyl-CoA(product ofβ-oxidation)via alteration of TCA cycle activity,but the modification has no significant impact on the hepatic FA oxidative capacity induced by PPARα.In addition,the availability of carnitine is a critical element to maintain FA oxidation during the neonatal period.

CPT1A in cancer: Tumorigenic roles and therapeutic implications

Metabolic reprogramming frequently occurs in the majority of cancers,wherein fatty acid oxidation(FAO)is usually induced and serves as a compensatory mechanism to improve energy consumption.Carnitine palmitoyltransferase 1A(CPT1A)is the rate-limiting enzyme for FAO and is widely involved in tumor growth,metastasis,and chemo-/radio-resistance.This review summarizes the most recent advances in understanding the oncogenic roles and mechanisms of CPT1A in tumorigenesis,including in proliferation and tumor growth,invasion and metastasis,and the tumor microenvironment.Importantly,CPT1A has been shown to be a biomarker for diagnosis and prognosis prediction and proved to be a candidate therapeutic target,especially for the treatment of drug-and radiation-resistant tumors.In summary,CPT1A plays remarkable roles in promoting cancer progression and is a potential anticancer therapeutic target.

Inhibition of nitric oxide synthase lowers fatty acid oxidation in ~reeclampsia-like mice at early gestational stage

Background Preeclampsia is one of hypertensive disorders in pregnancy. It is associated with abnormal lipid metabolism, including fatty acid oxidation metabolism. Long chain 3-hydroxyacyI-CoA dehydrogenase （LCHAD） plays an indispensable role in the oxidation of fatty acids. It has been reported that nitric oxide （NO） is one of the regulatory factors of the fatty acid oxidation pathway. The aim of this research was to investigate whether the nitric oxide synthase （NOS）inhibitor L-NAME may cause down-regulation of LCHAD in the pathogenesis of preeclampsia.Methods Pregnant wild-type （WT） mice were treated with L-NAME or normal saline （NS） during gestation days 7-18 （early group）, days 11-18 （mid group） and days 16-18 （late group）, and apoE-/- mice served as a control. Systolic blood pressure （SBP）, urine protein, feto-placental outcome, plasma lipid levels and NO concentrations were measured, and the expression of mRNA and protein for LCHAD in placental tissue were determined by real-time polymerase chain reaction （RT-PCR） and Western blotting, respectively.Results In WT and apoE-/- mice, SBP and urinary protein increased following L-NAME injection. Fetal and placental weights and NO concentrations were reduced and total cholesterol, triglycerides and free fatty acid levels were increased in early and mid L-NAME groups in WT and apoE-/- mice, compared with the NS group. There was no significant difference between the late L-NAME group and NS group. RT-PCR and Western blotting analysis showed that the mRNA and protein levels of LCHAD expression were significantly down-regulated in the early and mid L-NAME groups but not in the late L-NAME group in the WT and apoE-/- mice compared with the corresponding NS groups.Conclusions Inhibition of NO in early and mid gestation in mice may cause hyperlipidemia and suppression of fatty acid oxidation, whereas preeclampsia-like conditions in late gestation may be a maternal vascular response to inhibition of NO.

Rhodiola crenulata extract decreases fatty acid oxidation and autophagy to ameliorate pulmonary arterial hypertension by targeting inhibiton of acylcarnitine in rats

Pulmonary arterial hypertension(PAH)is a devastating pulmonary circulation disease lacking high-efficiency therapeutics.The present study aims to decipher the therapeutic mechanism of Rhodiola crenulata,a well-known traditional chinese medicine with cardiopulmonary protection capacity,on PAH by exploiting functional lipidomics.The rat model with PAH was successfully established for first,following Rhodiola crenulata water extract(RCE)treatment,then analysis of chemical constituents of RCE was performed,additional morphologic,hemodynamic,echocardiographic measurements were examined,further targeted lipidomics assay was performed to identify differential lipidomes,at last accordingly mechanism assay was done by combining qRT-PCR,Western blot and ELISA.Differential lipidomes were identified and characterized to differentiate the rats with PAH from healthy controls,mostly assigned to acylcarnitines,phosphatidylcholines,sphingomyelin associated with the PAH development.Excitingly,RCE administration reversed high level of decadienyl-L-carnitine by the modulation of metabolic enzyme CPT1A in mRNA and protein level in serum and lung in the rats with PAH.Furthermore,RCE was observed to reduce autophagy,confirmed by significantly inhibited PPARγ,LC3B,ATG7 and upregulated p62,and inactivated LKB1-AMPK signal pathway.Notably,we accurately identified the constituents in RCE,and delineated the therapeutic mechansim that RCE ameliorated PAH through inhibition of fatty acid oxidation and autophagy.Altogether,RCE might be a potential therapeutic medicine with multi-targets characteristics to prevent the progression of PAH.This novel findings pave a critical foundation for the use of RCE in the treatment of PAH.

T_3-induced liver AMP-activated protein kinase signaling:Redox dependency and upregulation of downstream targets

AIM: To investigate the redox dependency and promotion of downstream targets in thyroid hormone (T3)-induced AMP-activated protein kinase (AMPK) signaling as cellular energy sensor to limit metabolic stresses in the liver.

Constitutive androstane receptor agonist, TCPOBOP,attenuates steatohepatitis in the methionine choline-deficientdiet-fed mouse

AIM： To ascertain whether constitutive androstane receptor （CAR） activation by 1,4-bis-[2-（3,5,- dichloropyridyloxy）] benzene （TCPOBOP） modulates steatohepatitis in the methionine choline-deficient （MCD） diet-fed animal.METHODS： C57/BL6 wild-type mice were fed the MCD or standard diet for 2 wk and were treated with either the CAR agonist, TCPOBOP, or the CAR inverse agonist, androstanol.RESULTS： Expression of CYP2B10 and CYP3A11, known CAR target genes, increased 30-fold and 45-fold, respectively, in TCPOBOP-treated mice fed the MCD diet. TCPOBOP treatment reduced hepatic steatosis （44.6 ＋ 5.4% vs 30.4 ＋ 4.5%, P 〈 0.05） and serum triglyceride levels （48 ＋ 8 vs 20 ＋ 1 mg/dL, P 〈 0.05） in MCD diet- fed mice as compared with the standard diet-fed mice. This reduction in hepatic steatosis was accompanied by an increase in enzymes involved in fatty acid microsomal co-oxidation and peroxisomal p-oxidation, namely CYP4A10, LPBE, and 3-ketoacyI-CoA thiolase. The reduction in steatosis was also accompanied by a reduction in liver cell apoptosis and inflammation. In contrast, androstanol was without effect on any of the above parameters.CONCLUSION： CAR activation stimulates induction of genes involved in fatty acid oxidation, and ameliorates hepatic steatosis, apoptosis and inflammation.

Fatty acid oxidation and autophagy promote endoxifen resistance and counter the effect of AKT inhibition in ER-positive breast cancer cells

Tamoxifen(TAM)is the first-line endocrine therapy for estrogen receptor-positive(ER+)breast cancer(BC).However,acquired resistance occurs in∼50%cases.Meanwhile,although the PI3K/AKT/mTOR pathway is a viable target for treatment of endocrine therapy-refractory patients,complex signaling feedback loops exist,which can counter the effectiveness of inhibitors of this pathway.Here,we analyzed signaling pathways and metabolism in ER+MCF7 BC cell line and their TAM-resistant derivatives that are co-resistant to endoxifen using immunoblotting,quantitative polymerase chain reaction,and the Agilent Seahorse XF Analyzer.We found that activation of AKT and the energy-sensing kinase AMPK was increased in TAM and endoxifen-resistant cells.Furthermore,ERRα/PGC-1βand their target genes MCAD and CPT-1 were increased and regulated by AMPK,which coincided with increased fatty acid oxidation(FAO)and autophagy in TAM-resistant cells.Inhibition of AKT feedback-activates AMPK and ERRα/PGC-1β-MCAD/CPT-1 with a consequent increase in FAO and autophagy that counters the therapeutic effect of endoxifen and AKT inhibitors.Therefore,our results indicate increased activation of AKT and AMPK with metabolic reprogramming and increased autophagy in TAM-resistant cells.Simultaneous inhibition of AKT and FAO/autophagy is necessary to fully sensitize resistant cells to endoxifen.

Effects of Insulin Treatment on Intracellular Lipid Metabolism in Liver of Diabetic Rats

The effects and the mechanism of insulin treatment on intracellular lipid metabolism in liver of diabetic rats were evaluated. Type 2 diabetic rats were induced by injecting the streptozotocin （25 mg/kg） and fat rich food. According to the results of oral glucose tolerance test （OGTT） and glucose-induced insulin secretion test （IRT）, the rats were divided into two groups： untreated group （UT） and insulin-treated group （IT）. Normal rats （NC） served as controls. The treatment with either Humulin N （4-6 U/kg every day）, or saline lasted for 4 weeks. Body weight, OGTT, IRT, blood lipids, intracellular lipids in liver, hepatic fatty acid oxidation and the activity of fatty acid synthase （FAS） were detected. The change of liver histology was observed. The insulin sensitivity index （ISI） was applied to assess the status of insulin resistance. The results showed that as compared with NC group, the plasma and hepatic intracellular Triglyceride （TG）, total cholesterol （TC） and free fatty acids （FFAs） were increased significantly in UT group （P〈0.05）, and lipid droplets could be seen dispersedly in the liver specimens, the hepatic fatty acid oxidation was increased markedly （P〈0.05）, while the fatty acid synthase activity decreased （P〈0.05）. Insulin treatment resulted in a further accumulation of lipids in liver by 55.7 %, 19.87 % and 22.2 % increase in TG, TC, FFAs respectively. The size of hepatocytes was enlarged and the cells were filled with fat drops. Plasma lipids showed little decrease and still significantly higher than those in NC group after the insulin treatment. Meanwhile, insulin treatment was companied by 20 % decrease in the rate of fatty acid oxidation and 31 % increase in hepatic FAS activity compared to, UT group. It was concluded that treatment with insulin on type 2 diabetic rat increases hepatic intracellular lipid accumulation by inhibiting hepatic fatty acid oxidation and activating FAS.

Molecular mechanism of carvedilol in attenuating the reversion to fetal energy metabolism during cardiac hypertrophy development

Objective: To explore the molecular regulation mechanism of carvedilol in attenuating the reversion back towards fetal energy metabolism during the development of cardiac hypertrophy induced by coarctation of abdominal aorta (CAA) in male Wistar rats. Methods: Hemodynamic and ventricular remodeling parameters, free fatty acid content in the serum were measured in the experimental animals at 16 weeks after the surgical CAA, the rats receiving carvedilol intervention (CAR) after CAA, and those with sham operation (SH). The expressions of muscle carnitine palmitoyltransferaseⅠ (M-CPTⅠ) and medium chain acyl-CoA dehydrogenase (MCAD) mRNA in the cardiac myocytes from every group were studied with RT-PCR. Results: Significant left ventricular hypertrophy were observed in the rats 16 weeks after coarctation operation (P<0.05), together with significant free fatty acids accumulation and downregulation of M-CPTⅠ and MCAD mRNA (P<0.05) in CAA group. Carvedilol at a dose of 30 mg/kg/d for 12 weeks inhibited the left ventricular hypertrophy induced by pressure overload and enhanced the gene expressions of rate-limiting enzyme (M-CPTⅠ) and key enzyme of fatty acid (MCAD) in the CAR group compared with CAA group (P<0.05). Conclusion: Pressure overload-induced hypertrophy in CAA rats causes the reversion back towards fetal enery metabolism, that is, downregulates the expressions of rate-limiting enzyme and key enzyme of fatty acid oxidation. The intervention therapy with carvedilol, a vasodilating alpha- and beta-adrenoreceptor antagonist, attenuates the reversion of the metabolic gene expression to fetal type through upregulating M-CPTⅠ and MCAD mRNA expressions. Thus, carvedilol may exert cardioprotective effects on heart failure by the mechanism of preserving the adult metabolic gene regulation.