ABSTRACT
El ambiente obesogénico promueve la obesidad al facilitar el acceso y consumo de una amplia variedad de alimentos palatables altos en calorías. La activación del receptor de GLP1 (GLP1R) reduce la ingesta de alimentos, enlentece el vaciamiento gástrico y promueve un balance energético negativo a través de su acción en distintos órganos como el músculo esquelético, disminuyendo así el peso corporal. La obesidad inducida por dieta alta en grasa disminuye el efecto anorexigénico de la administración sistémica vía intra-peritoneal de EX4 (agonista de GLP1R). Sin embargo, se desconoce si la exposición a un ambiente obesogénico previo a la manifestación de obesidad disminuye los efectos anorexigénicos de EX4 o un posible efecto de EX4 sobre marcadores de oxidación de ácidos grasos y termogénesis en músculo esquelético. El objetivo de esta investigación fue determinar el efecto a corto plazo de la dieta CAF, un modelo del ambiente obesogénico humano, sobre la capacidad de EX4 de reducir la ingesta y modular la expresión de marcadores proteicos de oxidación de ácidos grasos y termogénesis (CPT1 y UCP2) en músculo de ratones. Nuestros datos muestran que una inyección intraperitoneal de EX4 a ratones C57BL/6J alimentados con dieta CAF o dieta control durante 10 días no altera la ingesta calórica total, peso corporal, o la expresión de proteínas marcadoras de los procesos de beta-oxidación y de termogénesis (CPT1 y UCP2). Estos datos sugieren que protocolos alternativos de administración de EX4 son necesarios para observar los efectos fisiológicos de la activación de GLP1R.
The obesogenic environment promotes obesity by facilitating access to and consumption of a wide variety of palatable, high-calorie foods. Activation of the GLP1 receptor (GLP1R) reduces food intake, slows gastric emptying, and promotes a negative energy balance by acting on organs such as skeletal muscle, thus decreasing body weight. Obesity induced by a high-fat diet decreased the anorexigenic effect of intraperitoneal systemic administration of EX4 (GLP1R agonist). However, it is unknown whether exposure to an obesogenic environment before the manifestation of obesity diminishes the anorexigenic effects of EX4 or a possible effect of EX4 on markers of fatty acid oxidation and thermogenesis in skeletal muscle. This investigation aimed to determine the short-term effect of the CAF diet, a model of the human obesogenic environment, on the ability of EX4 to reduce intake and modulate the expression of protein markers of fatty acid oxidation and thermogenesis (CPT1 and UCP2) in mouse muscle. Our data show that intraperitoneal injection of EX4 to C57BL/6J mice fed CAF diet or control diet for ten days does not alter total caloric intake, body weight, or expression of proteins markers of beta-oxidation and thermogenesis processes (CPT1 and UCP2). These data suggest that alternative EX4 administration protocols are necessary to observe the physiological effects of GLP1R activation.
Subject(s)
Animals , Male , Mice , Diet/adverse effects , Exenatide/administration & dosage , Obesity/etiology , Obesity/metabolism , Oxidation-Reduction , Blotting, Western , Muscle, Skeletal/metabolism , Thermogenesis , Fatty Acids/metabolism , Glucagon-Like Peptide-1 Receptor/metabolism , Uncoupling Protein 2 , Irinotecan , Injections, Intraperitoneal , Mice, Inbred C57BLABSTRACT
Objective:To investigate the changes of CPT1A and CPT1B protein expression in rat intestinal epithelial cells (IEC-6) after 60Co γ-ray irradiation, and the mechanism of the influence of carnitine palmitoyltransferase 1 (CPT1) on the proliferation of irradiated IEC-6 cells. Methods:IEC-6 cells were cultured in serum-normal medium or in serum-starved medium overnight, and pretreated with 20 μmol/L palmitic acid (PA) before irradiation with 0, 5, 10, and 15 Gy. At 24 h after irradiation, the cellular protein was collected for the measurement of CPT1A and CPT1B proteins by Western blot. The influences of ETO, an inhibitor of CPT1, on the survival and proliferation of irradiated IEC-6 cells were analyzed by colony formation assay and CCK-8 assay. The protein expressions and phosphorylation levels of the extracellular signal-regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK) in 5 Gy irradiated IEC-6 cells pre-treated with ETO were analyzed by Western blot at 48 h after radiation.Results:When IEC-6 cells were cultured in serum-normal medium together with PA, the protein level of CPT1A was significantly increased after 15 Gy irradiation ( t=-2.82, P<0.05). When IEC-6 cells were cultured in serum-starved medium, the protein level of CPT1A was significantly increased at 5, 10, and 15 Gy ( t=-3.28, -8.72, -8.67, P<0.05). When IEC-6 cells were cultured in serum-starved medium together with PA, the protein levels of CPT1A were significantly increased at 5, 10 and 15 Gy ( t=-10.69, -7.02, -8.23, P<0.05), the protein levels of CPT1B were significantly increased at 10 and 15 Gy ( t=-3.73, -5.05, P<0.05). After irradiation, the survival and proliferation of IEC-6 cells in ETO group were significantly lower than those in control group ( t=5.46, 13.22, P<0.05), and the protein level of ERK1/2 and p-JNK in ETO group were significantly lower than those in control group ( t=4.01, 3.29, 10.68, 14.44, P<0.05). Conclusions:CPT1 promoted radiation-induced IEC-6 injury cells survival and proliferation by enhancing the expression level of ERK1/2 protein and the activity of JNK.
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ObjectiveTo investigate the medicinal effect of total flavonoids of mulberry leaves on regulating liver lipid metabolism disorder in diabetes mellitus type 2 （T2DM） rats， and the mechanism based on liver peroxidase proliferators activate receptors-α （PPAR-α） and carnitine palmityl transferase-1 （CPT-1） proteins. MethodTotal flavonoids of mulberry leaves were extracted and purified by ethanol extraction + macroporous resin purification and then identified. T2DM rat model was induced by high fat diet （HFD） + streptozocin（STZ）method. Rats with blood glucose ≥ 11.1 mmol·L-1 were divided into three administration groups with the high dose （300 mg·kg-1）， medium dose （150 mg·kg-1）， and low dose （75 mg·kg-1） of total flavonoids of mulberry leaves for 8 weeks， respectively， to observe the weight and blood glucose of the rats. The pathological changes of rat livers were observed by hematoxylin-eosin （HE） staining. Biochemical method was used to detect the levels of total cholesterol （TC）， triglyceride （TG）， low density lipoprotein-cholesterol （LDL-C）， and high density lipoprotein-cholesterol （HDL-C） of blood lipid metabolism in rats. The messenger ribonucleic acid （mRNA） and protein expressions of PPAR-α and CPT-1 were determined by real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultAfter 8 weeks of intervention of total flavonoids of mulberry leaves， compared with the control group， the food intake， liver index， and fasting blood glucose of rats in the model group increased significantly （P<0.01）. Compared with the model group， the food intake， fasting blood glucose， and liver index of rats in the administration groups decreased significantly （P<0.01）. The results of HE staining showed that the liver tissue structure of rats in the control group was complete and there was no obvious abnormality. The model group showed vacuolar degeneration and inflammatory infiltration of hepatocytes of rats. There was no obvious abnormality in the liver structure of rats in the administration groups. The results of blood lipid showed that compared with the control group， the levels of TC， TG， and LDL-C increased significantly （P<0.01）， but the level of HDL-C decreased significantly （P<0.01） in the model group. Compared with the model group， the levels of TC， TG， and LDL-C decreased significantly （P<0.05， P<0.01）， whereas the level of HDL-C increased significantly （P<0.01） in the administration groups. The results of Real-time PCR showed that compared with the control group， the mRNA expression of PPAR-α and CPT-1 of rats in the model group decreased significantly （P<0.01）. Compared with the model group， the mRNA expressions of PPAR-α and CPT-1 of rats in the high-dose group increased significantly （P<0.01）. The results of Western blot showed that compared with the control group， the protein expressions of PPAR-α and CPT-1 of rats in the model group decreased significantly （P<0.01）. Compared with the model group， the protein expressions of PPAR-α and CPT-1 of rats in the high-dose group increased significantly （P<0.05， P<0.01）. ConclusionTotal flavonoids of mulberry leaves can effectively reduce blood glucose and improve liver lipid metabolism disorder in T2DM rats. The total flavonoids of mulberry leaves could regulate lipid metabolism and play a hypoglycemic role by activating and regulating PPAR-α and CPT-1 proteins and promoting oxidative decomposition of fatty acids.
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ObjectiveTo investigate the effect and mechanism of Mori Folium extract on the glucose and lipid metabolism disorders in the liver of rats with type 2 diabetes mellitus （T2DM） through the phosphatidylinositol 3-kinase/protein kinase B/peroxisome proliferation-activated receptor α/carnitine palmitoyl transferase-1 （PI3K/Akt/PPARα/CPT-1） signaling pathway. MethodThe T2DM model was induced by the high-fat diet combined with the intraperitoneal injection of streptozotocin （STZ）. The model rats were randomly divided into a model group， a metformin （0.2 g·kg-1） group， and a Mori Folium water extract （4.0 g·kg-1） group according to blood glucose and body weight. In the 8-week administration， fasting blood glucose was measured at the same time every week. The histomorphological and fat changes in the rat liver were observed by hematoxylin-eosin （HE） staining and oil red O staining. The levels of total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）， alanine aminotransferase （ALT）， and aspartate aminotransferase （AST） in the serum were measured by biochemical methods. Western blot （WB） was used to quantitatively detect the protein expression of p-PI3K，PI3K，p-Akt，Akt，PPARα，and CPT-1 in the rat liver. ResultAfter 8-week administration， the blood glucose of rats was higher in the model group than that in the control group （P<0.01）， and lower in the Mori Folium water extract group than that in the model group （P<0.01）. The results of HE staining showed that the liver tissue structure of the control group was complete， and the hepatocytes were arranged radially around the central vein， while the hepatocyte injury in the model group was obvious. Compared with the model group， the Mori Folium water extract group showed improved vacuolar degeneration and no lesions such as small bile duct hyperplasia. Oil red O staining showed that there was no obvious steatosis and necrosis in the hepatocytes of rats in the control group， and no lipid droplets in the hepatocytes were observed， while the model group showed increased lipid droplets. Mori Folium significantly reduced the lipid droplets in the liver. Biochemical analysis showed that the levels of TC， TG， LDL-C， AST， and ALT in the model group were significantly higher than those in control group （P<0.01）. The levels of TC， TG， LDL-C， AST， and ALT in the Mori Folium water extract group were significantly lower than those in the model group （P<0.05，P<0.01）. WB showed that the protein expression of p-PI3K/PI3K， p-Akt/Akt， PPARα， and CPT-1 in the model group were lower than those in the control group （P<0.01）. Mori Folium water extract could increase the protein expression of p-PI3K/PI3K， p-Akt/Akt， PPARα， and CPT-1 （P<0.05 or P<0.01）. ConclusionThe hypoglycemic mechanism of Mori Folium water extract may be related to the regulation of the PI3K/Akt/PPARα/CPT-1 signaling pathway.
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@#[Abstract] Objective: To investigate the mechanisms of carnitine palmitoyltransferase 1c (CPT1c) expression to affect the proliferation and apoptosis of human thyroid papillary cancer B-CPAP cells through the AMP-dependent/activated protein kinase (AMPK) pathway in the low glucose and hypoxic conditions. Methods: Firstly,humanthyroidpapillarycarcinomaB-CPAP cells were cultured under normal condition or low glucose and hypoxic condition respectively, followed with the treatment of AMPK inhibitor compound C. Western blotting was used to detect the expressions of AMPK, p-AMPK, peroxisome proliferator-activated receptor α (PPARα) and CPT1c; the proliferation and apoptosis were detected by CCK-8 and Flow cytometry, respectively. Then PPARα-siRNA was synthesized and transfected into B-CPAP cells to knock down PPARα, and then the cells were cultured under normal or low glucose and hypoxic condition respectively.Above indicators were also detected to verify the regulation of PPARα on CPT1c. Finally, the human luciferase reporter plasmid containing CPT1c gene promoter was constructed, and the effect of PPARα on the activity of CPT1c promoter luciferase activity was observed by immunofluorescence. Results: The expressions ofAMPK, p-AMPK, PPARα and CPT1c were significantly increased in B-CPAP cells under low glucose and hypoxia condition (P<0.05 or P<0.01), while cell proliferation and apoptosis rate did not change significantly (P>0.05). After the treatment of AMPK inhibitor compound C, the expressions of p-AMPK, PPARα and CPT1c in low glucose and hypoxia group were significantly decreased (P<0.05 or P<0.01), the inhibitory rate on cell proliferation and apoptosis rate were significantly increased (P<0.05). However, the change range was smaller than that in the normal culture + compound C group (P<0.05).After PPARα knockdown, the expressions ofAMPK, p-AMPK, PPARα and CPT1c in cancer cells cultured under normal conditions were significantly decreased (P<0.05 or P<0.01), and the inhibitory rate on cell proliferation and apoptosis rate were significantly increased (P<0.05). While under low glucose and hypoxia condition, the expression of CPT1c in cells after transfection was significantly decreased (P<0.05), and the inhibition rate on cell proliferation and the apoptosis rate were significantly increased (P<0.05); However, the change range was still lower than that of normal condition group after transfection (P<0.05).After PPARα overexpression, the ratio of fluorescence in the empty vector group was not significantly different from that of the blank group (P>0.05), and the ratio of fluorescence was significantly increased in PPARα over-expression group (P<0.05). Conclusions: AMPK can increase the expression of PPARα to promote the expression of CPT1c in thyroid cancer B-CPAP cells under low glucose and hypoxia conditions, thereby inhibiting cell apoptosis and maintaining cell proliferation ability.
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Objective To explore the effect of the combination of carnitine palmityl transferase 1( CPT1) inhibitor etomoxir and chemotherapy drug cisplatin on lung cancer cell line A549 proliferation and migration of lung cancer. Methods CCK8 was applied to investigate the effect of the combination of etomoxir and cisplatin on A549 survival. Transwell test was used to detect migration of lung cancer cell line A549 treated with the combination of etomoxir and cisplatin. Apoptosis of A549 was detected by annexin V/PI. A549 transplanted mice were used to test therapeu-tic effect of etomoxir combined with cisplatin. Results Tumor cells proliferation and migration were inhibited by the combination of etomoxir and cisplatin. Apoptosis of tumor cells was enhanced by the combination of etomoxir. After the treatment of the combination of etomoxir and cisplatin, tumor growth of mouse was inhibited. Conclusions The combination of etomoxir and cisplatin can decrease tumor cells survival and induce tumor cells apoptosis, and then inhibit tumor growth in mouse lung cancer model.
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Objective To study the effects of the Yinlingtong capsules on intracellular triglyceride,fatty acid oxidation levels and CPT-1/ACC-β in HHL-5 cells.Methods After treated HHL-5 cells with different doses Yinlingtong capsules,intracellular triglyceride content and the fatty acid oxidation level were detected by the kits.The CPT-1β and ACC-β mRNA levels were detected by Q-PCR.Results Yinlingtong capsules could reduce triglyceride content (compared with the control group,triglyceride content of0.5,1 and 2 mg/ml dose group were reduced by 9.5％,14.3％ and 19.4％,respectively),enhance the level of fatty acid oxidation by a dose-response relationship(compared with the control group,the level of fatty acid oxidation of 0.5,1and 2 mg/ml dose group were increased 4.3％,6.9％ and 11.2％,respectively),but could not affect the CPT-1βand ACC-β mRNA levels.Conclusion Yinlingtong capsules reduced the accumulation of fat in HHL-5 hepatocytes,and the specific impact mechanism needs to be further explored.
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This study determined the effects of fucoxanthin on gene expressions related to lipid metabolism in rats with a high-fat diet. Rats were fed with normal fat diet (NF, 7% fat) group, high fat diet group (HF, 20% fat), and high fat with 0.2% fucoxanthin diet group (HF+Fxn) for 4 weeks. Body weight changes and lipid profiles in plasma, liver, and feces were determined. The mRNA expressions of transcriptional factors such as sterol regulatory element binding protein (SREBP)-1c, Carnitine palmitoyltransferase-1 (CPT1), Cholesterol 7alpha-hydroxylase1 (CYP7A1) as well as mRNA expression of several lipogenic enzymes were determined. Fucoxanthin supplements significantly increased plasma high density lipoprotein (HDL) concentration (P < 0.05). The hepatic total lipids, total cholesterols, and triglycerides were significantly decreased while the fecal excretions of total lipids, cholesterol, and triglycerides were significantly increased in HF+Fxn group (P < 0.05). The mRNA expression of hepatic Acetyl-CoA carboxylase (ACC), Fatty acid synthase (FAS), and Glucose-6-phosphate dehydrogenase (G6PDH) as well as SREBP-1C were significantly lower in HF+Fxn group compared to the HF group (P < 0.05). The hepatic mRNA expression of Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) and Acyl-CoA cholesterol acyltransferase (ACAT) were significantly low while lecithin-cholesterol acyltransferase (LCAT) was significantly high in the HF+Fxn group (P < 0.05). There was significant increase in mRNA expression of CPT1 and CYP7A1 in the HF+Fxn group, compared to the HF group (P < 0.05). In conclusion, consumption of fucoxanthin is thought to be effective in improving lipid and cholesterol metabolism in rats with a high fat diet.
Subject(s)
Animals , Rats , Acetyl-CoA Carboxylase , Body Weight Changes , Carnitine , Carrier Proteins , Cholesterol , Coenzyme A , Diet , Diet, High-Fat , Fatty Acid Synthases , Feces , Gene Expression , Glucosephosphate Dehydrogenase , Lipid Metabolism , Lipogenesis , Lipoproteins , Liver , Plasma , RNA, Messenger , Sterol O-Acyltransferase , Sterol Regulatory Element Binding Protein 1 , Triglycerides , XanthophyllsABSTRACT
Postmenopausal women or ovariectomized rats are associated with increased cholesterol levels, which are risk factors of metabolic syndrome and cardiovascular diseases. Increased prevalence of metabolic syndrome after menopause might be associated with estradiol deficiency. Harmful effect of estradiol hampers the casual usage of hormone to prevent the metabolic syndrome. Soy protein has been reported to show several beneficial effects on health, however it is unclear which components of soy protein is responsible for anti-obesity and hypocholesterolemic effects. Soy isoflavones, genistein and daizein, are suggested to have anti-obesity and hypocholesterolemic effects but with inconsistency. The present study investigated the effect of supplementation of genistein (experiment I) and soy protein containing isoflavones (experiment II) to high fat diet on body weight gain, food intake, liver and fat tissue weight and the lipid levels in ovariectomized rats. Plasma and hepatic lipid contents and the mRNA levels of genes encoding lipid metabolism related proteins, such as CPT1 and HMGR were measured. Ovariectomy increased body weight, fat tissue weight and plasma and hepatic lipid levels which increase the risk of metabolic syndrome. Soy protein could improve plasma and hepatic lipids levels. Soy protein also increased hepatic CPT1 and HMGR mRNA levels. Plasma and hepatic lipids levels could not be decreased by dietary genistein alone. In contrast, lipids levels could be decreased by isoflavone-fortified soy protein, suggesting that the ingestion of soy protein enriched with isoflavone gives more benefit for protecting postmenopausal women from metabolic syndrome.