Progress 10/01/12 to 09/30/13
Outputs
Progress Report Objectives (from AD-416): Elevated fat levels within skeletal muscle cells (intramyocellular lipids) are highly correlated with muscle and whole-body insulin resistance, and more prevalent in obesity. The molecular links and metabolic shifts driving this association remain open to debate, but notably, reduced muscle mitochondrial fatty acid (FA) beta-oxidation is more prevalent among insulin-resistant/diabetic persons. Therefore, discovery of biomarkers reflective of the status of an individual�s muscle FA beta- oxidation activity or capacity would have tremendous prognostic and diagnostic value in terms of diabetes. Furthermore, characterization of metabolites associated with muscle mitochondrial fat metabolism should uncover candidate signaling factors which tie FA �-oxidation to insulin signaling. We propose to identify, for the first time, specific biomarkers of muscle FA beta-oxidation using multiple metabolomic analytical platforms to compare metabolite profiles in samples derived from biological systems displaying disparate muscle fat combustion, including: isolated mitochondrial organelles and muscle cells catabolizing FA at different rates, a UCP3 transgenic animal model, and human subjects harboring a UCP3 truncation polymorphism. Pilot validation studies will test whether plasma metabolites and/or metabolite signatures identified in cell, animal, and human studies that track muscular FA beta- oxidation can be experimentally increased in obese, insulin-resistant subjects via a diet-exercise regimen designed to improve muscle fitness and FA combustion. Approach (from AD-416): A comprehensive carnitine and acylcarnitine assay measuring >40 acylcarnitines will be employed to test samples derived from the following project aims: Aim 1--Identify Metabolite Biomarkers of Muscle Fat Combustion in Organelle, Cell, and Animal Models Displaying Significantly Altered Fatty Acid beta-Oxidation. We will determine how metabolite profiles shift in models displaying increased muscle beta-oxidation (uncoupling protein 3- overexpressing muscle cell line and muscle UCP3-transgenic mice), and hypothesize that profiles in UCP3-overexpressing systems will reflect increased FA beta-oxidation. Complementary studies will identify tissue- specific metabolites generated by mitochondria in the course of palmitate catabolism in vitro, comparing muscle to liver and kidney preparations. Aim 2--Identify Metabolite Biomarkers of Muscle Fat Combustion in Humans Harboring a UCP3 Missense Polymorphic Allele. We predict that subjects with this polymorphism (that yields a truncated UCP3 and 50% decreased whole-body fat combustion) will display a distinctive plasma metabolite profile indicative of reduced muscle FA oxidation, when compared to subjects without the polymorphism. Aim 3--Determine Whether Metabolomic Profiles Reflective of Muscle Fat Combustion Predict Metabolic Health Changes Following Diet & Exercise Intervention in Obese Subjects. We hypothesize that biomarkers reflective of normal to increased muscle beta-oxidation will be increased, and markers indicative of poor muscle fat combustion reduced, in a cohort of sedentary obese subjects undergoing a 4 month diet-exercise protocol which will increase muscle fitness and improve insulin action. This research relates to objective 3 of the inhouse project, �Determine mechanisms underlying the regulation of body weight and disorders associated with obesity, by examining hormonal, neuronal, and metabolite pathways linking adipose and non-adipose tissues, and characterizing tissue-specific inflammation in humans, cells, and animal models". Studies to determine plasma concentrations of acylcarnitines in human subjects continue. Specifically, samples from obese bariatric surgery patients have been completed and data are being analyzed. Other samples from the University of Alabama clinical test site are planned to be analyzed in the FY2014 timeframe.
Impacts
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Progress 10/01/11 to 09/30/12
Outputs
Progress Report Objectives (from AD-416): Elevated fat levels within skeletal muscle cells (intramyocellular lipids) are highly correlated with muscle and whole-body insulin resistance, and more prevalent in obesity. The molecular links and metabolic shifts driving this association remain open to debate, but notably, reduced muscle mitochondrial fatty acid (FA) beta-oxidation is more prevalent among insulin-resistant/diabetic persons. Therefore, discovery of biomarkers reflective of the status of an individual�s muscle FA beta- oxidation activity or capacity would have tremendous prognostic and diagnostic value in terms of diabetes. Furthermore, characterization of metabolites associated with muscle mitochondrial fat metabolism should uncover candidate signaling factors which tie FA �-oxidation to insulin signaling. We propose to identify, for the first time, specific biomarkers of muscle FA beta-oxidation using multiple metabolomic analytical platforms to compare metabolite profiles in samples derived from biological systems displaying disparate muscle fat combustion, including: isolated mitochondrial organelles and muscle cells catabolizing FA at different rates, a UCP3 transgenic animal model, and human subjects harboring a UCP3 truncation polymorphism. Pilot validation studies will test whether plasma metabolites and/or metabolite signatures identified in cell, animal, and human studies that track muscular FA beta- oxidation can be experimentally increased in obese, insulin-resistant subjects via a diet-exercise regimen designed to improve muscle fitness and FA combustion. Approach (from AD-416): A comprehensive carnitine and acylcarnitine assay measuring >40 acylcarnitines will be employed to test samples derived from the following project aims: Aim 1--Identify Metabolite Biomarkers of Muscle Fat Combustion in Organelle, Cell, and Animal Models Displaying Significantly Altered Fatty Acid beta-Oxidation. We will determine how metabolite profiles shift in models displaying increased muscle beta-oxidation (uncoupling protein 3- overexpressing muscle cell line and muscle UCP3-transgenic mice), and hypothesize that profiles in UCP3-overexpressing systems will reflect increased FA beta-oxidation. Complementary studies will identify tissue- specific metabolites generated by mitochondria in the course of palmitate catabolism in vitro, comparing muscle to liver and kidney preparations. Aim 2--Identify Metabolite Biomarkers of Muscle Fat Combustion in Humans Harboring a UCP3 Missense Polymorphic Allele. We predict that subjects with this polymorphism (that yields a truncated UCP3 and 50% decreased whole-body fat combustion) will display a distinctive plasma metabolite profile indicative of reduced muscle FA oxidation, when compared to subjects without the polymorphism. Aim 3--Determine Whether Metabolomic Profiles Reflective of Muscle Fat Combustion Predict Metabolic Health Changes Following Diet & Exercise Intervention in Obese Subjects. We hypothesize that biomarkers reflective of normal to increased muscle beta-oxidation will be increased, and markers indicative of poor muscle fat combustion reduced, in a cohort of sedentary obese subjects undergoing a 4 month diet-exercise protocol which will increase muscle fitness and improve insulin action. This research contributes to objectives 3 and 6 of the in-house parent project. Studies that examine blood and tissue metabolites during exercise are geared to discovering unique muscle-specific patterns of metabolism, that may be dysregulated in obesity, pre-diabetes, and the type 2 diabetic states. The team has analyzed blood plasma before and during exercise in obese, pre-diabetic women and compared results of a comprehensive acylcarnitine metabolite panel to samples derived after the subjects lost weight and improved physical activity. The final results will be forthcoming in FY2013, and preliminary findings indicate that unique metabolites reflective of incomplete fatty acid combustion are increased by exercise.
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Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) Elevated fat levels within skeletal muscle cells (intramyocellular lipids) are highly correlated with muscle and whole-body insulin resistance, and more prevalent in obesity. The molecular links and metabolic shifts driving this association remain open to debate, but notably, reduced muscle mitochondrial fatty acid (FA) beta-oxidation is more prevalent among insulin-resistant/diabetic persons. Therefore, discovery of biomarkers reflective of the status of an individual�s muscle FA beta- oxidation activity or capacity would have tremendous prognostic and diagnostic value in terms of diabetes. Furthermore, characterization of metabolites associated with muscle mitochondrial fat metabolism should uncover candidate signaling factors which tie FA �-oxidation to insulin signaling. We propose to identify, for the first time, specific biomarkers of muscle FA beta-oxidation using multiple metabolomic analytical platforms to compare metabolite profiles in samples derived from biological systems displaying disparate muscle fat combustion, including: isolated mitochondrial organelles and muscle cells catabolizing FA at different rates, a UCP3 transgenic animal model, and human subjects harboring a UCP3 truncation polymorphism. Pilot validation studies will test whether plasma metabolites and/or metabolite signatures identified in cell, animal, and human studies that track muscular FA beta- oxidation can be experimentally increased in obese, insulin-resistant subjects via a diet-exercise regimen designed to improve muscle fitness and FA combustion. Approach (from AD-416) A comprehensive carnitine and acylcarnitine assay measuring >40 acylcarnitines will be employed to test samples derived from the following project aims: Aim 1--Identify Metabolite Biomarkers of Muscle Fat Combustion in Organelle, Cell, and Animal Models Displaying Significantly Altered Fatty Acid beta-Oxidation. We will determine how metabolite profiles shift in models displaying increased muscle beta-oxidation (uncoupling protein 3- overexpressing muscle cell line and muscle UCP3-transgenic mice), and hypothesize that profiles in UCP3-overexpressing systems will reflect increased FA beta-oxidation. Complementary studies will identify tissue- specific metabolites generated by mitochondria in the course of palmitate catabolism in vitro, comparing muscle to liver and kidney preparations. Aim 2--Identify Metabolite Biomarkers of Muscle Fat Combustion in Humans Harboring a UCP3 Missense Polymorphic Allele. We predict that subjects with this polymorphism (that yields a truncated UCP3 and 50% decreased whole-body fat combustion) will display a distinctive plasma metabolite profile indicative of reduced muscle FA oxidation, when compared to subjects without the polymorphism. Aim 3--Determine Whether Metabolomic Profiles Reflective of Muscle Fat Combustion Predict Metabolic Health Changes Following Diet & Exercise Intervention in Obese Subjects. We hypothesize that biomarkers reflective of normal to increased muscle beta-oxidation will be increased, and markers indicative of poor muscle fat combustion reduced, in a cohort of sedentary obese subjects undergoing a 4 month diet-exercise protocol which will increase muscle fitness and improve insulin action. Significant progress has been made toward several of the objectives in the related project (5306-51530-016-09R), which examines broad metabolite patterns reflective of metabolic status in muscle in order to identify biomarkers of muscle fat combustion. This overarching aim is driven by the fact that poor insulin sensitivity and frank type 2 diabetes typically occur in the setting of reduced or inefficient muscle long chain fatty acid (LCFA) catabolism in mitochondria. In FY2011, the research team continued to work with colleagues at Case Western Reserve who continue to support the analytical aspects of acylcarnitines in human plasma and other biofluids derived from studies associated with the parent project. The Case Western acylcarnitine assay was used to verify levels of these metabolites in cell culture media. Other interactions related to provision of historic information from scientist collaborators regarding the concentrations of acylcarnitines in tissue from normal individuals and those harboring metabolic disease. The Principal Investigator and cooperator exchange information and results via email regularly, and the cooperator provides edits on manuscripts and presentations, as well as assists with results analysis.
Impacts
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) Elevated fat levels within skeletal muscle cells (intramyocellular lipids) are highly correlated with muscle and whole-body insulin resistance, and more prevalent in obesity. The molecular links and metabolic shifts driving this association remain open to debate, but notably, reduced muscle mitochondrial fatty acid (FA) beta-oxidation is more prevalent among insulin-resistant/diabetic persons. Therefore, discovery of biomarkers reflective of the status of an individual�s muscle FA beta- oxidation activity or capacity would have tremendous prognostic and diagnostic value in terms of diabetes. Furthermore, characterization of metabolites associated with muscle mitochondrial fat metabolism should uncover candidate signaling factors which tie FA �-oxidation to insulin signaling. We propose to identify, for the first time, specific biomarkers of muscle FA beta-oxidation using multiple metabolomic analytical platforms to compare metabolite profiles in samples derived from biological systems displaying disparate muscle fat combustion, including: isolated mitochondrial organelles and muscle cells catabolizing FA at different rates, a UCP3 transgenic animal model, and human subjects harboring a UCP3 truncation polymorphism. Pilot validation studies will test whether plasma metabolites and/or metabolite signatures identified in cell, animal, and human studies that track muscular FA beta- oxidation can be experimentally increased in obese, insulin-resistant subjects via a diet-exercise regimen designed to improve muscle fitness and FA combustion. Approach (from AD-416) A comprehensive carnitine and acylcarnitine assay measuring >40 acylcarnitines will be employed to test samples derived from the following project aims: Aim 1--Identify Metabolite Biomarkers of Muscle Fat Combustion in Organelle, Cell, and Animal Models Displaying Significantly Altered Fatty Acid beta-Oxidation. We will determine how metabolite profiles shift in models displaying increased muscle beta-oxidation (uncoupling protein 3- overexpressing muscle cell line and muscle UCP3-transgenic mice), and hypothesize that profiles in UCP3-overexpressing systems will reflect increased FA beta-oxidation. Complementary studies will identify tissue- specific metabolites generated by mitochondria in the course of palmitate catabolism in vitro, comparing muscle to liver and kidney preparations. Aim 2--Identify Metabolite Biomarkers of Muscle Fat Combustion in Humans Harboring a UCP3 Missense Polymorphic Allele. We predict that subjects with this polymorphism (that yields a truncated UCP3 and 50% decreased whole-body fat combustion) will display a distinctive plasma metabolite profile indicative of reduced muscle FA oxidation, when compared to subjects without the polymorphism. Aim 3--Determine Whether Metabolomic Profiles Reflective of Muscle Fat Combustion Predict Metabolic Health Changes Following Diet & Exercise Intervention in Obese Subjects. We hypothesize that biomarkers reflective of normal to increased muscle beta-oxidation will be increased, and markers indicative of poor muscle fat combustion reduced, in a cohort of sedentary obese subjects undergoing a 4 month diet-exercise protocol which will increase muscle fitness and improve insulin action. Documents Grant with Case Western Reserve University. Formerly 5306-51530-016-10G (8/09) Significant progress has been made toward several of the objectives in the parent project (5306-51530-016-09R), which examines broad metabolite patterns reflective of metabolic status in muscle in order to identify biomarkers of muscle fat combustion. This overarching aim is driven by the fact that poor insulin sensitivity and frank type 2 diabetes typically occur in the setting of reduced or inefficient muscle long chain fatty acid (LCFA) catabolism in mitochondria. In FY2010, the research team continued to work with Dr. Hoppel and colleagues at Case Western Reserve continue to support the analytical aspects of acylcarnitines in human plasma and other biofluids derived from studies associated with the parent project. Recently, the Case Western acylcarnitine assay was used to verify levels of these metabolites in cell culture media and in human plasma from subjects treated with select nutrients thought to improve metabolic function. The latter results indicate that as hypothesized, metabolite patterns reflective of sub- optimal mitochondrial function in micronutrient-deficient subjects can be normalized by administration of the micronutrient; further studies are planned to confirm this observation in a different population. The PI and cooperator exchange information and results via email regularly, and the cooperator provides edits on manuscripts and presentations, as well as assists with results analysis.
Impacts
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) Elevated fat levels within skeletal muscle cells (intramyocellular lipids) are highly correlated with muscle and whole-body insulin resistance, and more prevalent in obesity. The molecular links and metabolic shifts driving this association remain open to debate, but notably, reduced muscle mitochondrial fatty acid (FA) beta-oxidation is more prevalent among insulin-resistant/diabetic persons. Therefore, discovery of biomarkers reflective of the status of an individual�s muscle FA beta- oxidation activity or capacity would have tremendous prognostic and diagnostic value in terms of diabetes. Furthermore, characterization of metabolites associated with muscle mitochondrial fat metabolism should uncover candidate signaling factors which tie FA �-oxidation to insulin signaling. We propose to identify, for the first time, specific biomarkers of muscle FA beta-oxidation using multiple metabolomic analytical platforms to compare metabolite profiles in samples derived from biological systems displaying disparate muscle fat combustion, including: isolated mitochondrial organelles and muscle cells catabolizing FA at different rates, a UCP3 transgenic animal model, and human subjects harboring a UCP3 truncation polymorphism. Pilot validation studies will test whether plasma metabolites and/or metabolite signatures identified in cell, animal, and human studies that track muscular FA beta- oxidation can be experimentally increased in obese, insulin-resistant subjects via a diet-exercise regimen designed to improve muscle fitness and FA combustion. Approach (from AD-416) A comprehensive carnitine and acylcarnitine assay measuring >40 acylcarnitines will be employed to test samples derived from the following project aims: Aim 1--Identify Metabolite Biomarkers of Muscle Fat Combustion in Organelle, Cell, and Animal Models Displaying Significantly Altered Fatty Acid beta-Oxidation. We will determine how metabolite profiles shift in models displaying increased muscle beta-oxidation (uncoupling protein 3- overexpressing muscle cell line and muscle UCP3-transgenic mice), and hypothesize that profiles in UCP3-overexpressing systems will reflect increased FA beta-oxidation. Complementary studies will identify tissue- specific metabolites generated by mitochondria in the course of palmitate catabolism in vitro, comparing muscle to liver and kidney preparations. Aim 2--Identify Metabolite Biomarkers of Muscle Fat Combustion in Humans Harboring a UCP3 Missense Polymorphic Allele. We predict that subjects with this polymorphism (that yields a truncated UCP3 and 50% decreased whole-body fat combustion) will display a distinctive plasma metabolite profile indicative of reduced muscle FA oxidation, when compared to subjects without the polymorphism. Aim 3--Determine Whether Metabolomic Profiles Reflective of Muscle Fat Combustion Predict Metabolic Health Changes Following Diet & Exercise Intervention in Obese Subjects. We hypothesize that biomarkers reflective of normal to increased muscle beta-oxidation will be increased, and markers indicative of poor muscle fat combustion reduced, in a cohort of sedentary obese subjects undergoing a 4 month diet-exercise protocol which will increase muscle fitness and improve insulin action. Documents Grant with Case Western Reserve University. Significant Activities that Support Special Target Populations Significant progress has been made toward several of the objectives in the parent project (5306-51530-016-09R), which examines broad metabolite patterns reflective of metabolic status in muscle in order to identify biomarkers of muscle fat combustion. This overarching aim is driven by the fact that poor insulin sensitivity and frank type 2 diabetes typically occur in the setting of reduced or inefficient muscle long chain fatty acid (LCFA) catabolism in mitochondria. In FY2009, the research team has published a significant paper outlining the finding that metabolite by-products of inefficient LCFA combustion (chain- shortened acylcarnitine moieties) are elevated in the plasma of type 2 diabetic African-American women. Scientists at Case Western Reserve continue to support the analytical aspects of acylcarnitines in human plasma and other biofluids derived from studies associated with the parent project. Recently, the Case Western acylcarnitine assay was used to verify levels of these metabolites in cell culture media and in human plasma from subjects treated with select nutrients thought to improve metabolic function. The latter positive proof-of-concept studies have triggered additional efforts to assess acylcarnitine status in specific populations thought to suffer from some nutrient deficiencies. The ADODR monitors the annual financial report from cooperating institutions, and conducts in-person or teleconference discussion sessions relating to the project.
Impacts
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