Objective To explore the effects of zinc-0t2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HF1))-induced obesity in mice and the possible mechanism. Methods Thirty-six male mice were fed with ...Objective To explore the effects of zinc-0t2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HF1))-induced obesity in mice and the possible mechanism. Methods Thirty-six male mice were fed with standard food (SF) (n=9) and HFD (n=27), respectively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase (FAS) and hormone sensitive lipase (HSL) in liver tissue were deterlnined by reverse transcription-polymerase chain reaction. Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice (0.51±0.10 AU vs. 0.75±0.07 AU, P〈0.01). Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight (r =-0.56, P〈0.001), epididymal fat mass (r=-0.67, P〈O. 001), percentage of epididymal fat (r= 0.65, P〈0.001), and increased weight (r= 0.57, P〈0.001) in simple SF- and HFD fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididyreal fat. Furthermore, FAS mRNA expression decreased (P〈0.01) and HSL mRNA expression increased (P〈0.001) in the liver in ZAG over-expressing mice. Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and increased HSL expression in the liver of obese mice.展开更多
Fatty acid synthase (FAS) attracts more and more attention recently as a potential target for metabolic syndrome,such as cancer, obesity, diabetes and cerebrovascular disease. FAS inhibitors are widely existed in pl...Fatty acid synthase (FAS) attracts more and more attention recently as a potential target for metabolic syndrome,such as cancer, obesity, diabetes and cerebrovascular disease. FAS inhibitors are widely existed in plants, consisting of diversiform compounds. These inhibitors exist not only in herbs also in many plant foods, such as teas, allium vegetables and some fruits. These effective components include gallated catechins, theaflavins,flavonoids, condensed and hydrolysable tannins, thioethers,pentacyclic triterpenes, stilbene derivatives, etc, and they target at the different domains of FAS, showing different inhibitory mechanisms. Interestingly, these FAS inhibitor-contained herbs and plant foods and their effective components are commonly related to the prevention of metabolic syndromes including fatreducing and depression of cancer. From biochemical angle,FAS can control the balance between energy provision and fat production. Some studies have shown that the effects of those effective components in plants on metabolic syndromes are mediated by inhibiting FAS. This suggests that FAS plays a critical role in the regulation of energy metabolism, and the FAS inhibitors from plants have significant potential application value in the treatment and prevention of metabolic syndromes.展开更多
AIM: To evaluate the possible role of Tribble 3 (TRB3) in a rat model of non-alcoholic fatty liver disease (NAFLD) and its signal transduction mechanism.METHODS: Thirty Sprague-Dawley rats were randomized into t...AIM: To evaluate the possible role of Tribble 3 (TRB3) in a rat model of non-alcoholic fatty liver disease (NAFLD) and its signal transduction mechanism.METHODS: Thirty Sprague-Dawley rats were randomized into three groups: normal control group, non-alcoholic fatty liver group A (fed on a high-fat diet for 8 wk) and group B (fed on a high-fat diet for 16 wk). To determine the degree of hepatic steatosis in rats of each group, livers were stained with hematoxylin and eosin, and evaluated; real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction was performed to measure the expression levels of TRI33 mRNA, and Western blotting analysis was done to determine the expression levels of protein kinase B (Akt) and phosphorylated protein kinase B (p-Akt-Thr308, p-Akt-Ser473).RESULTS: Hepatic steatosis was evident in both NAFLD groups: mild to moderate hepatic steatosis occurred in group A, mainly as mild steatosis.Moderate to severe hepatic steatosis occurred in group B, mainly as severe steatosis. The expression level of TRB3 mRNA in group B was significantly higher than in the control group (122.28 ± 95.37 vs 3.06 ± 2.33,P = 0.002) and group A (122.28 ± 95.37 vs 5.77 ± 4.20,P = 0.001). There was no significant difference in the expression levels of Akt (1.03 ± 0.53 vs 1.12 ± 0.77,P = 0.729) and p-Akt-Thr308 (0.82 ± 0.45 vs 0.92 ± 0.38, P = 0.592) between group A and the control group. The expression level of Akt and p-Akt-Thr308 in group B was significantly lower than in group A (Akt 0.41 ± 0.16 vs 1.12 ± 0.77, P = 0.008; p-Akt-Thr308 0.47 ± 0.19 vs 0.82 ± 0.45, P = 0.036) and the control group (Akt 0.41 ± 0.16 vs 1.03 ± 0.53, P = 0.018;p-Akt-Thr308 0.47 ± 0.19 vs 0.92 ± 0.38, P = 0.010).The expression level of p-Akt-Ser473 in group A was significantly higher than in group B (1.48 ± 0.50 vs 0.81± 0.39, P = 0.041) as well as the control group (1.48 ± 0.50 vs 0.45 ± 0.26, P = 0.003).CONCLUSION: TRB3 blocks insulin signaling by inhibiting Akt activation, which contributes to insulin resistance. It may be an important factor in the occurrence and development of NAFLD.展开更多
Non-alcoholic fatty liver disease (NAFLD) has been recognized as a major health burden. It is the most important cause of chronic liver disease and a major in- dependent cardiovascular risk factor. Lacking a definit...Non-alcoholic fatty liver disease (NAFLD) has been recognized as a major health burden. It is the most important cause of chronic liver disease and a major in- dependent cardiovascular risk factor. Lacking a definite treatment for NAFLD, a specific diet and an increase in physical activity represent the most commonly used therapeutic approaches. In this review, major literature data about the use of omega-3 polyunsaturated fatty ac- ids (n-3 PUFAs) as a potential treatment of NAFLD have been described, n-3 PUFAs, besides having a beneficial impact on most of the cardio-metabolic risk factors (hy- pertension, hyperlipidemia, endothelial dysfunction and atherosclerosis) by regulating gene transcription factors [i.e., peroxisome proliferator-activated receptor (PPAR) cz, PPARy, sterol regulatory element-binding protein-i, carbohydrate responsive element-binding protein], im- pacts both lipid metabolism and on insulin sensitivity. In addition to an enhancement of hepatic beta oxidation and a decrease of the endogenous lipid production, n-3 PUFAs are able to determine a significant reduction of the expression of pro-inflammatory molecules (tumor necrosis factor-~ and interleukin-6) and of oxygen reac- tive species. Further strengthening the results of the in vitro studies, both animal models and human interven- tion trials, showed a beneficial effect of n-3 PUFAs on the severity of NAFLD as expressed by laboratory pa- rameters and imaging measurements. Despite available results provided encouraging data about the efficacy of n-3 PUFAs as a treatment of NAFLD in humans, well- designed randomized controlled trials of adequate size and duration, with histological endpoints, are needed to assess the long-term safety and efficacy of PUFA, as well as other therapies, for the treatment of NAFLD and non-alcoholic steatohepatitis patients. It is worthwhile to consider that n-3 PUFAs cannot be synthesized by the human body and must be derived from exogenous sources (fish oil, flaxseeds, olive oil) which are typical foods of the Mediterranean diet, known for its beneficial effects in preventing obesity, diabetes and, in turn, cardiovascular events. According to these data, it is important to consider that most of the beneficial effects of n-3 PUFAs can also be obtained by an equilibrate nutrition program.展开更多
基金Supported by the National Natural Science Foundation of China (30771026)Beijing Natural Science Foundation (7082079)
文摘Objective To explore the effects of zinc-0t2-glycoprotein (ZAG) on body weight and body fat in high-fat-diet (HF1))-induced obesity in mice and the possible mechanism. Methods Thirty-six male mice were fed with standard food (SF) (n=9) and HFD (n=27), respectively. Five weeks later, 9 mice fed with HFD were subjected to ZAG expression plasmid DNA transfection by liposome transfection method, and another 9 mice to negative control plasmid transfection. Two weeks later, serum ZAG level in the mice was assayed by Western blot, and the effects of ZAG over-expression on body weight, body fat, serum biochemical indexes, and adipose tissue of obese mice were evaluated. The mRNA expressions of fatty acid synthase (FAS) and hormone sensitive lipase (HSL) in liver tissue were deterlnined by reverse transcription-polymerase chain reaction. Results Serum ZAG level significantly lowered in simple HFD-fed mice in comparison to SF-fed mice (0.51±0.10 AU vs. 0.75±0.07 AU, P〈0.01). Further statistical analysis demonstrated that ZAG level was negatively correlated with body weight (r =-0.56, P〈0.001), epididymal fat mass (r=-0.67, P〈O. 001), percentage of epididymal fat (r= 0.65, P〈0.001), and increased weight (r= 0.57, P〈0.001) in simple SF- and HFD fed mice. ZAG over-expression in obese mice reduced body weight and the percentage of epididyreal fat. Furthermore, FAS mRNA expression decreased (P〈0.01) and HSL mRNA expression increased (P〈0.001) in the liver in ZAG over-expressing mice. Conclusions ZAG is closely related to obesity. Serum ZAG level is inversely correlated with body weight and percentage of body fat. The action of ZAG is associated with reduced FAS expression and increased HSL expression in the liver of obese mice.
文摘Fatty acid synthase (FAS) attracts more and more attention recently as a potential target for metabolic syndrome,such as cancer, obesity, diabetes and cerebrovascular disease. FAS inhibitors are widely existed in plants, consisting of diversiform compounds. These inhibitors exist not only in herbs also in many plant foods, such as teas, allium vegetables and some fruits. These effective components include gallated catechins, theaflavins,flavonoids, condensed and hydrolysable tannins, thioethers,pentacyclic triterpenes, stilbene derivatives, etc, and they target at the different domains of FAS, showing different inhibitory mechanisms. Interestingly, these FAS inhibitor-contained herbs and plant foods and their effective components are commonly related to the prevention of metabolic syndromes including fatreducing and depression of cancer. From biochemical angle,FAS can control the balance between energy provision and fat production. Some studies have shown that the effects of those effective components in plants on metabolic syndromes are mediated by inhibiting FAS. This suggests that FAS plays a critical role in the regulation of energy metabolism, and the FAS inhibitors from plants have significant potential application value in the treatment and prevention of metabolic syndromes.
文摘AIM: To evaluate the possible role of Tribble 3 (TRB3) in a rat model of non-alcoholic fatty liver disease (NAFLD) and its signal transduction mechanism.METHODS: Thirty Sprague-Dawley rats were randomized into three groups: normal control group, non-alcoholic fatty liver group A (fed on a high-fat diet for 8 wk) and group B (fed on a high-fat diet for 16 wk). To determine the degree of hepatic steatosis in rats of each group, livers were stained with hematoxylin and eosin, and evaluated; real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction was performed to measure the expression levels of TRI33 mRNA, and Western blotting analysis was done to determine the expression levels of protein kinase B (Akt) and phosphorylated protein kinase B (p-Akt-Thr308, p-Akt-Ser473).RESULTS: Hepatic steatosis was evident in both NAFLD groups: mild to moderate hepatic steatosis occurred in group A, mainly as mild steatosis.Moderate to severe hepatic steatosis occurred in group B, mainly as severe steatosis. The expression level of TRB3 mRNA in group B was significantly higher than in the control group (122.28 ± 95.37 vs 3.06 ± 2.33,P = 0.002) and group A (122.28 ± 95.37 vs 5.77 ± 4.20,P = 0.001). There was no significant difference in the expression levels of Akt (1.03 ± 0.53 vs 1.12 ± 0.77,P = 0.729) and p-Akt-Thr308 (0.82 ± 0.45 vs 0.92 ± 0.38, P = 0.592) between group A and the control group. The expression level of Akt and p-Akt-Thr308 in group B was significantly lower than in group A (Akt 0.41 ± 0.16 vs 1.12 ± 0.77, P = 0.008; p-Akt-Thr308 0.47 ± 0.19 vs 0.82 ± 0.45, P = 0.036) and the control group (Akt 0.41 ± 0.16 vs 1.03 ± 0.53, P = 0.018;p-Akt-Thr308 0.47 ± 0.19 vs 0.92 ± 0.38, P = 0.010).The expression level of p-Akt-Ser473 in group A was significantly higher than in group B (1.48 ± 0.50 vs 0.81± 0.39, P = 0.041) as well as the control group (1.48 ± 0.50 vs 0.45 ± 0.26, P = 0.003).CONCLUSION: TRB3 blocks insulin signaling by inhibiting Akt activation, which contributes to insulin resistance. It may be an important factor in the occurrence and development of NAFLD.
文摘Non-alcoholic fatty liver disease (NAFLD) has been recognized as a major health burden. It is the most important cause of chronic liver disease and a major in- dependent cardiovascular risk factor. Lacking a definite treatment for NAFLD, a specific diet and an increase in physical activity represent the most commonly used therapeutic approaches. In this review, major literature data about the use of omega-3 polyunsaturated fatty ac- ids (n-3 PUFAs) as a potential treatment of NAFLD have been described, n-3 PUFAs, besides having a beneficial impact on most of the cardio-metabolic risk factors (hy- pertension, hyperlipidemia, endothelial dysfunction and atherosclerosis) by regulating gene transcription factors [i.e., peroxisome proliferator-activated receptor (PPAR) cz, PPARy, sterol regulatory element-binding protein-i, carbohydrate responsive element-binding protein], im- pacts both lipid metabolism and on insulin sensitivity. In addition to an enhancement of hepatic beta oxidation and a decrease of the endogenous lipid production, n-3 PUFAs are able to determine a significant reduction of the expression of pro-inflammatory molecules (tumor necrosis factor-~ and interleukin-6) and of oxygen reac- tive species. Further strengthening the results of the in vitro studies, both animal models and human interven- tion trials, showed a beneficial effect of n-3 PUFAs on the severity of NAFLD as expressed by laboratory pa- rameters and imaging measurements. Despite available results provided encouraging data about the efficacy of n-3 PUFAs as a treatment of NAFLD in humans, well- designed randomized controlled trials of adequate size and duration, with histological endpoints, are needed to assess the long-term safety and efficacy of PUFA, as well as other therapies, for the treatment of NAFLD and non-alcoholic steatohepatitis patients. It is worthwhile to consider that n-3 PUFAs cannot be synthesized by the human body and must be derived from exogenous sources (fish oil, flaxseeds, olive oil) which are typical foods of the Mediterranean diet, known for its beneficial effects in preventing obesity, diabetes and, in turn, cardiovascular events. According to these data, it is important to consider that most of the beneficial effects of n-3 PUFAs can also be obtained by an equilibrate nutrition program.