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SUN-P003: Liver Glycogen Metabolism in Mice Exposed to Hypoxia
S46 Research supported by FAPESP 2011/09612-3 and Scholarship DD 2013/03246-0. Disclosure of Interest: None declared
SUN-P003 LIVER GLYCOGEN METABOLISM IN MICE EXPOSED TO HYPOXIA N. Watanabe1,2, M. Sato1, Y. Hara1. 1Showa Women’s University, 2 Institute of Women’s Health Sciences, Tokyo, Japan Rationale: Chronic obstructive pulmonary disease and mountain sickness result in the suppression of physical activity followed by biogenic hypoxia. This suppression might be induced by the decrease in the amount of glycogen in the liver and skeletal muscles, because glucose utilization increases remarkably under hypoxic conditions. Here, we validated changes in glycogen metabolism in mice exposed to hypoxia. Methods: Eight-week-old male C57/BL6J mice were divided into 2 experimental groups (n = 8). The mice in the hypoxia group were exposed to 10.5% oxygen for 6 hours, while those in the control group were maintained under normoxic conditions, i.e., 21.0% oxygen. After exposure, the mice were sacrificed and their blood, liver, skeletal muscle, and hearts were collected. Glycogen contents in the liver, skeletal muscle, and hearts were measured. In addition, the mRNA expression of glycogen synthase and glycogen phosphorylase was measured using real-time polymerase chain reaction. Results: Glycogen content in the liver and heart increased up to 563% and 153%, respectively, after exposure to hypoxia for 6 hours but that in the skeletal muscle did not show significant increase. The relative gene expressions of glycogen synthase and glycogen phosphorylase decreased and increased, respectively, but the differences were not significant. In the liver, ATP levels were significantly decreased and lipid peroxidation was significantly increased in the hypoxia group. Conclusion: Contrary to our expectations, the glycogen level in the liver increased remarkably upon exposure to hypoxia. Disclosure of Interest: None declared
SUN-P004 OXYGEN CONSUMPTION BY MITOCHONDRIA OF PLATELETS FROM PATIENTS ON LONG-TERM PARENTERAL NUTRITION (PN) S. Osowska1, P. Kowalczyk2, M. Kunecki3, M. Radkowski4, K. Perlejewski4, K. Majewska1, J. Sobocki4. 1Szpital Im. Orłowskiego, 2Bionicum Ltd, Warszawa, 3Pirogow Hospital, Łódz,́ 4Warsaw Medical University, Warszawa, Poland Rationale: Molecular oxygen is the key substrate of aerobic metabolism. Knowledge of cell oxygenation is central to a detailed understanding of how cellular metabolic responses are modified by disease and by treatment. Patients with intestinal failure patients are constantly exposed to parenteral nutrition (PN), which may affect metabolism and oxygen consumption in cells. Methods: We obtained platelets from blood samples of 36 patients with intestinal failure on long-term PN and 42 sex- and age-matched healthy controls. The patients were on PN for more than 2 years. Patients with ongoing acute infections were excluded from the study. The measurements of oxygen
Poster consumption were performed by a fluorescence based assay, using the MitoXpress Xtra kit (Luxcel Biosciences), which allows real time analysis of the concentration of dissolved molecular oxygen. Statistical analysis was performed using Student’s t-test. Results: The average oxygen consumption by mitochondria from platelets of intestinal failure patients on long-term PN was higher (19.58 ± 3.15 μs/min) than by those from the control group (18.19 ± 1.82 μs/min). The two groups were statistically significant ( p = 0.006). Conclusion: We show that respiratory processes in platelets from long-term PN patients are not disturbed and may even be raised compared to healthy controls. Whether this reflects an alteration in substrate for oxidative metabolism and whether it is positive or negative effect is not clear. Further studies are needed to better understand this process. Disclosure of Interest: None declared
SUN-P005 GENISTEIN, AN ISOFLAVONE PRESENT IN SOY, IMPROVES LIPID AND CHOLESTEROL METABOLISM IN MICE FED A HIGH CHOLESTEROL DIET O. Granados1, M. D. R. Guizar1, A. Tovar1. 1INCMNSZ, Mexico DF, Mexico Rationale: Genistein, an isoflavone from soy, has a differential effect on trans-activation of LXR transcription factor isoforms. That is, once activated LXR by its synthetic ligand, T0901317, it was capable of downregulate lipogenic genes commanded by LXRα, whereas genes of reverse cholesterol transport (RTC) were overexpressed through LXRβ. These effects appear to have been caused by the action of AMPK. So, the aim of this study was to evaluate in vivo the effect of genistein on activation of AMPK and trans-activation of LXR. Methods: We fed mice with a diet high in cholesterol (0.2%) and with or without the addition of genistein (0.2%) for 2 months. Through PCR-real time and Western blot we measured genes and proteins involved in lipogenesis, TRC and AMPK activation. Results: The animals in the presence of cholesterol and genistein gained significantly less weight than other experimental groups. Furthermore, genistein showed a tendency to improve glucose tolerance. The relative mRNA expression SREBP1c is unchanged in either group. However, ACC and FAS mRNA was higher in the groups of casein and soy in the presence of cholesterol and genistein. Interestingly, by measuring the protein level, these experimental groups showed a lower level of protein in the presence of cholesterol and genistein regardless of the type of protein. The pACC/ACC ratio was also higher in these groups, suggesting a repression of lipogenesis by the action of genistein. In contrast, protein levels of RTC (ABCG5/ABCG8) did not differ with the treatment of cholesterol and genistein regardless of the type of protein. Finally, the ratio of pAMPK/AMPK showed a higher AMPK activation by genistein en presence of cholesterol. Conclusion: These findings indicate that genistein may transactivate the effects of LXR via AMPK and suggest that it may use as therapeutic agent to improve hepatic steatosis. Disclosure of Interest: None declared
SUN-P003 LIVER GLYCOGEN METABOLISM IN MICE EXPOSED TO HYPOXIA N. Watanabe1,2, M. Sato1, Y. Hara1. 1Showa Women’s University, 2 Institute of Women’s Health Sciences, Tokyo, Japan Rationale: Chronic obstructive pulmonary disease and mountain sickness result in the suppression of physical activity followed by biogenic hypoxia. This suppression might be induced by the decrease in the amount of glycogen in the liver and skeletal muscles, because glucose utilization increases remarkably under hypoxic conditions. Here, we validated changes in glycogen metabolism in mice exposed to hypoxia. Methods: Eight-week-old male C57/BL6J mice were divided into 2 experimental groups (n = 8). The mice in the hypoxia group were exposed to 10.5% oxygen for 6 hours, while those in the control group were maintained under normoxic conditions, i.e., 21.0% oxygen. After exposure, the mice were sacrificed and their blood, liver, skeletal muscle, and hearts were collected. Glycogen contents in the liver, skeletal muscle, and hearts were measured. In addition, the mRNA expression of glycogen synthase and glycogen phosphorylase was measured using real-time polymerase chain reaction. Results: Glycogen content in the liver and heart increased up to 563% and 153%, respectively, after exposure to hypoxia for 6 hours but that in the skeletal muscle did not show significant increase. The relative gene expressions of glycogen synthase and glycogen phosphorylase decreased and increased, respectively, but the differences were not significant. In the liver, ATP levels were significantly decreased and lipid peroxidation was significantly increased in the hypoxia group. Conclusion: Contrary to our expectations, the glycogen level in the liver increased remarkably upon exposure to hypoxia. Disclosure of Interest: None declared
SUN-P004 OXYGEN CONSUMPTION BY MITOCHONDRIA OF PLATELETS FROM PATIENTS ON LONG-TERM PARENTERAL NUTRITION (PN) S. Osowska1, P. Kowalczyk2, M. Kunecki3, M. Radkowski4, K. Perlejewski4, K. Majewska1, J. Sobocki4. 1Szpital Im. Orłowskiego, 2Bionicum Ltd, Warszawa, 3Pirogow Hospital, Łódz,́ 4Warsaw Medical University, Warszawa, Poland Rationale: Molecular oxygen is the key substrate of aerobic metabolism. Knowledge of cell oxygenation is central to a detailed understanding of how cellular metabolic responses are modified by disease and by treatment. Patients with intestinal failure patients are constantly exposed to parenteral nutrition (PN), which may affect metabolism and oxygen consumption in cells. Methods: We obtained platelets from blood samples of 36 patients with intestinal failure on long-term PN and 42 sex- and age-matched healthy controls. The patients were on PN for more than 2 years. Patients with ongoing acute infections were excluded from the study. The measurements of oxygen
Poster consumption were performed by a fluorescence based assay, using the MitoXpress Xtra kit (Luxcel Biosciences), which allows real time analysis of the concentration of dissolved molecular oxygen. Statistical analysis was performed using Student’s t-test. Results: The average oxygen consumption by mitochondria from platelets of intestinal failure patients on long-term PN was higher (19.58 ± 3.15 μs/min) than by those from the control group (18.19 ± 1.82 μs/min). The two groups were statistically significant ( p = 0.006). Conclusion: We show that respiratory processes in platelets from long-term PN patients are not disturbed and may even be raised compared to healthy controls. Whether this reflects an alteration in substrate for oxidative metabolism and whether it is positive or negative effect is not clear. Further studies are needed to better understand this process. Disclosure of Interest: None declared
SUN-P005 GENISTEIN, AN ISOFLAVONE PRESENT IN SOY, IMPROVES LIPID AND CHOLESTEROL METABOLISM IN MICE FED A HIGH CHOLESTEROL DIET O. Granados1, M. D. R. Guizar1, A. Tovar1. 1INCMNSZ, Mexico DF, Mexico Rationale: Genistein, an isoflavone from soy, has a differential effect on trans-activation of LXR transcription factor isoforms. That is, once activated LXR by its synthetic ligand, T0901317, it was capable of downregulate lipogenic genes commanded by LXRα, whereas genes of reverse cholesterol transport (RTC) were overexpressed through LXRβ. These effects appear to have been caused by the action of AMPK. So, the aim of this study was to evaluate in vivo the effect of genistein on activation of AMPK and trans-activation of LXR. Methods: We fed mice with a diet high in cholesterol (0.2%) and with or without the addition of genistein (0.2%) for 2 months. Through PCR-real time and Western blot we measured genes and proteins involved in lipogenesis, TRC and AMPK activation. Results: The animals in the presence of cholesterol and genistein gained significantly less weight than other experimental groups. Furthermore, genistein showed a tendency to improve glucose tolerance. The relative mRNA expression SREBP1c is unchanged in either group. However, ACC and FAS mRNA was higher in the groups of casein and soy in the presence of cholesterol and genistein. Interestingly, by measuring the protein level, these experimental groups showed a lower level of protein in the presence of cholesterol and genistein regardless of the type of protein. The pACC/ACC ratio was also higher in these groups, suggesting a repression of lipogenesis by the action of genistein. In contrast, protein levels of RTC (ABCG5/ABCG8) did not differ with the treatment of cholesterol and genistein regardless of the type of protein. Finally, the ratio of pAMPK/AMPK showed a higher AMPK activation by genistein en presence of cholesterol. Conclusion: These findings indicate that genistein may transactivate the effects of LXR via AMPK and suggest that it may use as therapeutic agent to improve hepatic steatosis. Disclosure of Interest: None declared