ABSTRACT: Transcription profiling of rat ventricle samples from streptozotocin (STZ)-diabetic animals to investigate mitochondrial long-chain free fatty acid export
Project description:vanEunen2013 - Network dynamics of fatty acid β-oxidation (time-course model)
Lipid metabolism plays an important role in the development of metabolic syndrome, a major risk factor for cardiovascular disease and diabetes. This model gives insights into the response of lipid oxidation to dietart and medical interventions. The model predicts the rate of lipid oxidation and the time course of most acyl carnitines. There are two models described in the paper, (i) steady-state model [ BIOMD0000000505
], (ii) time-course model [ BIOMD0000000506
]. This model corresponds to the time-course model.
This model is described in the article:
Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.
van Eunen K, Simons SM, Gerding A, Bleeker A, den Besten G, Touw CM, Houten SM, Groen BK, Krab K, Reijngoud DJ, Bakker BM.
PLoS Comput Biol. 2013;9(8):e1003186.
Abstract:
Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH). The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000506
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
Project description:vanEunen2013 - Network dynamics of fatty acid β-oxidation (steady-state model)
Lipid metabolism plays an important role in the development of metabolic syndrome, a major risk factor for cardiovascular disease and diabetes. This model gives insights into the response of lipid oxidation to dietart and medical interventions. The model predicts the rate of lipid oxidation and the time course of most acyl carnitines. There are two models described in the paper, (i) steady-state model [ BIOMD0000000505
], (ii) time-course model [ BIOMD0000000506
]. This model corresponds to the steady-state model.
This model is described in the article:
Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.
van Eunen K, Simons SM, Gerding A, Bleeker A, den Besten G, Touw CM, Houten SM, Groen BK, Krab K, Reijngoud DJ, Bakker BM.
PLoS Comput Biol. 2013;9(8):e1003186.
Abstract:
Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH). The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.
This model is hosted on BioModels Database
and identified
by: BIOMD0000000505
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource
for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to the public
domain worldwide. Please refer to CC0 Public Domain
Dedication
for more information.
Project description:Skeletal muscle mitochondrial dysfunction is secondary to T2DM and can be improved by long-term regular exercise training Mitochondrial dysfunction has long been implicated to play a causative role in development of type 2 diabetes (T2DM). However, a growing number of recent studies provide data that mitochondrial dysfunction is a consequence of T2DM development. The aim of our study is to clarify in further detail the causal role of mitochondrial dysfunction in T2DM by a comprehensive ex vivo analysis of mitochondrial function combined with global gene expression analysis in muscle of pre-diabetic newly diagnosed untreated T2DM subjects and long-standing insulin treated T2DM subjects compared with age- and BMI-matched controls. In addition, we assessed the impact of long-term interval exercise training on physical activity performance, mitochondrial function and glycemic control in long-standing insulin-treated T2DM subjects. Ex vivo mitochondrial density, quality and functioning was comparable between pre-diabetic subjects and matched controls, however, gene expression analysis showed a switch from carbohydrate toward lipids as energy source in pre-diabetes subjects. In contrast, long-term insulin treated T2DM subjects had slightly decreased mitochondrial density and ex vivo function. Expression of Krebs cycle and OXPHOS related genes were decreased, indicating a decreased capacity to use lipids as an energy source. The insulin-treated T2DM subjects had a lower physical activity level than pre-diabetic and normoglycemic subjects. A 52 weeks exercise training of these subjects increased submaximal oxidative efficiency, increased in vivo PCr recovery rate, as well as mildly increased in vitro mitochondrial function. Gene expression of β-oxidation, Krebs cycle and OXPHOS-related genes was increased. Our data demonstrate that mitochondrial dysfunction is rather a consequence than a causative factor in T2DM development as it was only detected in overt diabetes and not in early diabetes. Regular exercise training stabilized exogenous insulin requirement and improved mitochondrial functioning, fatty acid oxidation and general physical work load capacity in long-standing insulin-treated T2DM subjects. As such, the present study shows for the first time that long-term exercise interventions are beneficial in this group of complex diabetes patient and may prevent further metabolic deterioration. Insulin-treated T2DM subjects before and after 52 weeks of exercise training (T2DM_0 and T2DM_52), normoglycemic controls (NGT) and pre-diabetes subjects (IGT) and were selected. RNA was extracted from skeletal muscle biopsies and hybridized on Affymetrix microarrays.
Project description:We analyzed the effects of enarodustat (JTZ-951; HIF stabilizer) on renal energy metabolism in streptozotocin-induced diabetic rat model. Transcriptome analysis of renal cortex revealed that genes related to fatty acid metabolism and amino acid metabolism were upregulated in diabetes and downregulated by enarodustat, whereas genes related to glucose metabolism were upregulated by enarodustat. Thus, HIF stabilization counteracts the renal energy metabolism alterations occurring in the early stages of diabetic kidney disease.
Project description:In this study we have analyzed gene expression and metabolite levels in the livers of male and female Zucker diabetic fatty (ZDF) rats. We speculated that the sex different development of diabetes in the ZDF animals presents the opportunity to relate gender to diabetes (since only males become diabetic on normal diet). In this model one can search for parameters that distinguish females fed normal diet compared to high fat diet (i.e. components that vary with the development of diabetes) and evaluate if such changes can be related to components that characterize male diabetic animals.. Biological replicates: 4 ZDF female rat livers from rats on a standard diet (SD) and 4 ZDF female rat livers from rats on high-fat diet (HFD) (6 weeks). One replicate per array. Hepatic gene expression, hepatic metabolites, sex-differences
Project description:In this study we have analyzed gene expression and metabolite levels in the livers of male and female Zucker diabetic fatty (ZDF) rats. We speculated that the sex different development of diabetes in the ZDF animals presents the opportunity to relate gender to diabetes (since only males become diabetic on normal diet). In this model one can search for parameters that distinguish females fed normal diet compared to high fat diet (i.e. components that vary with the development of diabetes) and evaluate if such changes can be related to components that characterize male diabetic animals.. Biological replicates: 4 male ZDF rat livers from rats on a standard diet (SD) and 4 ZDF female rat livers from rats on a standard diet (SD). One replicate per array. Hepatic gene expression, hepatic metabolites, sex-differences
Project description:Cardiomyopathy in type 1 diabetic patients is characterized by early onset diastolic and late onset systolic dysfunction. The mechanism underlying development of diastolic and systolic dysfunction in diabetes remains unknown. We used microarrays to detail the ventricle gene expression changes that underly development of diabetic cardiomyopathy. We identified distinct classes of up-regulated genes during this process. Experiment Overall Design: 150g male Wistar rats (Harlan) we injected with 65 mg/kg streptozotocin to induce Type 1 diabetes. Four replicates of Control and Diabetic rat ventricles were removed and frozen at Three time points for total RNA isolation and hybridization on the Affymetrix RG-U34A microarray. The 3 day samples show a baseline for initial diabetic changes in the ventricle. The 28 day samples show changes associated with diastolic dysfunction in diabetes. The 42 day samples show changes associated with both diastolic and systolic dysfunction in type 1 diabetic rat ventricles.
Project description:Podocyte injury in diabetic kidney disease contributes to the development of albuminuria and subsequent renal decline. Clinically, gastric bypass surgery is associated with reductions in albuminuria, and rodent studies demonstrate coherent improvements in renal histology. We aimed to investigate the mechanisms underpinning remission of albuminuria following gastric bypass focussing on podocyte injury. Firstly, we tracked the evolution of albuminuria and cognate evidence of histological and ultrastructural damage to the glomerulus in male Zucker Diabetic Fatty rats. Secondly, we examined the impact of gastric bypass in these rats, focussing on podocyte injury. Thirdly, we conducted a global transcriptomic study profiling the shift in the renal transcriptome in the Zucker Diabetic Fatty rats rat and its relevance to human disease. Lastly, we explored whether gastric bypass could reverse the changes seen in the disease associated transcriptome. Albuminuria in the Zucker Diabetic Fatty rat developed by 12 weeks of age. This was accompanied by glomerulomegaly, podocyte stress and ultrastructural evidence of podocyte dedifferentiation. When animals underwent gastric bypass at 12 weeks of age, marked reductions in albuminuria in association with normalisation of glomerular tuft size, attenuation of podocyte stress and improvements in podocyte foot process morphology were observed within 2 months of surgery. A characteristic disease associated gene expression signature was observed in the kidneys of Zucker Diabetic Fatty rats, with a core set of alterations conserved in global analysis of the human DKD transcriptome. Many of the shared gene expression alterations were reversed by gastric bypass. Reductions in podocyte injury represent a key mechanism underpinning the remission of albuminuria following gastric bypass.
Project description:Skeletal muscle mitochondrial dysfunction is secondary to T2DM and can be improved by long-term regular exercise training Mitochondrial dysfunction has long been implicated to play a causative role in development of type 2 diabetes (T2DM). However, a growing number of recent studies provide data that mitochondrial dysfunction is a consequence of T2DM development. The aim of our study is to clarify in further detail the causal role of mitochondrial dysfunction in T2DM by a comprehensive ex vivo analysis of mitochondrial function combined with global gene expression analysis in muscle of pre-diabetic newly diagnosed untreated T2DM subjects and long-standing insulin treated T2DM subjects compared with age- and BMI-matched controls. In addition, we assessed the impact of long-term interval exercise training on physical activity performance, mitochondrial function and glycemic control in long-standing insulin-treated T2DM subjects. Ex vivo mitochondrial density, quality and functioning was comparable between pre-diabetic subjects and matched controls, however, gene expression analysis showed a switch from carbohydrate toward lipids as energy source in pre-diabetes subjects. In contrast, long-term insulin treated T2DM subjects had slightly decreased mitochondrial density and ex vivo function. Expression of Krebs cycle and OXPHOS related genes were decreased, indicating a decreased capacity to use lipids as an energy source. The insulin-treated T2DM subjects had a lower physical activity level than pre-diabetic and normoglycemic subjects. A 52 weeks exercise training of these subjects increased submaximal oxidative efficiency, increased in vivo PCr recovery rate, as well as mildly increased in vitro mitochondrial function. Gene expression of β-oxidation, Krebs cycle and OXPHOS-related genes was increased. Our data demonstrate that mitochondrial dysfunction is rather a consequence than a causative factor in T2DM development as it was only detected in overt diabetes and not in early diabetes. Regular exercise training stabilized exogenous insulin requirement and improved mitochondrial functioning, fatty acid oxidation and general physical work load capacity in long-standing insulin-treated T2DM subjects. As such, the present study shows for the first time that long-term exercise interventions are beneficial in this group of complex diabetes patient and may prevent further metabolic deterioration.
Project description:In the present study, we explored the hypothesis that the fatty liver phenotype and associated gene expression changes associated with the specific deletion of the POR gene in adult mouse liver could be abrogated by supplementation of the mouse diet with the very long chain highly unsaturated fatty acids, arachidonic acid (C20:4ω6), eicosapentaenoic acid (C20:5ω3) and docosahexaenoic acid (C22:6ω3). We expected the fatty liver phenotype would not be reduced by the polyunsaturated fatty acids linoleic (C18:2ω6) or linolenic acid (C18:3ω3), since these accumulated in the fatty livers of LivPORKO animals. This proved to be the case. However, we also made two surprising observations. First, control animals fed a diet enriched in PUFA had fatty livers and gene expression profiles similar to animals fed a lard diet, which was deficient in both PUFA and HUFA. Second, while a diet enriched in HUFA did result in reduced steatosis in livers of the LivPOKO animals, fat accumulation was still elevated relative to controls. Array analyses indicated most differences in gene expression were related to fatty acid metabolism and could explain differences in fat accumulation in LivPORKO livers with dietary treatment.