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Colasante C, Bonilla-Martinez R, Berg T, Windhorst A, Baumgart-Vogt E. Peroxisomes during postnatal development of mouse endocrine and exocrine pancreas display cell-type- and stage-specific protein composition. Cell Tissue Res 2023:10.1007/s00441-023-03766-6. [PMID: 37126142 DOI: 10.1007/s00441-023-03766-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/15/2023] [Indexed: 05/02/2023]
Abstract
Peroxisomal dysfunction unhinges cellular metabolism by causing the accumulation of toxic metabolic intermediates (e.g. reactive oxygen species, very -chain fatty acids, phytanic acid or eicosanoids) and the depletion of important lipid products (e.g. plasmalogens, polyunsaturated fatty acids), leading to various proinflammatory and devastating pathophysiological conditions like metabolic syndrome and age-related diseases including diabetes. Because the peroxisomal antioxidative marker enzyme catalase is low abundant in Langerhans islet cells, peroxisomes were considered scarcely present in the endocrine pancreas. Recently, studies demonstrated that the peroxisomal metabolism is relevant for pancreatic cell functionality. During the postnatal period, significant changes occur in the cell structure and the metabolism to trigger the final maturation of the pancreas, including cell proliferation, regulation of energy metabolism, and activation of signalling pathways. Our aim in this study was to (i) morphometrically analyse the density of peroxisomes in mouse endocrine versus exocrine pancreas and (ii) investigate how the distribution and the abundance of peroxisomal proteins involved in biogenesis, antioxidative defence and fatty acid metabolism change during pancreatic maturation in the postnatal period. Our results prove that endocrine and exocrine pancreatic cells contain high amounts of peroxisomes with heterogeneous protein content indicating that distinct endocrine and exocrine cell types require a specific set of peroxisomal proteins depending on their individual physiological functions. We further show that significant postnatal changes occur in the peroxisomal compartment of different pancreatic cells that are most probably relevant for the metabolic maturation and differentiation of the pancreas during the development from birth to adulthood.
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Affiliation(s)
- Claudia Colasante
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus Liebig -University, Aulweg 123, 35392, Giessen, Germany
| | - Rocio Bonilla-Martinez
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus Liebig -University, Aulweg 123, 35392, Giessen, Germany
| | - Timm Berg
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus Liebig -University, Aulweg 123, 35392, Giessen, Germany
| | - Anita Windhorst
- Institute for Medical Informatic, Justus Liebig University, Rudolf-Buchheim-Str. 6, 35392, Gießen, Germany
| | - Eveline Baumgart-Vogt
- Institute for Anatomy and Cell Biology, Medical Cell Biology, Justus Liebig -University, Aulweg 123, 35392, Giessen, Germany.
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Beshlawy AE, Abd El Dayem SM, Mougy FE, Gafar EAE, Samir H. Screening of growth hormone deficiency in short thalassaemic patients and effect of L-carnitine treatment. Arch Med Sci 2010; 6:90-5. [PMID: 22371726 PMCID: PMC3278949 DOI: 10.5114/aoms.2010.13513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 11/23/2008] [Accepted: 12/16/2008] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Evaluation of growth hormone (GH) in short thalassaemic patients and effect of L-carnitine therapy in those with hormone deficiency. MATERIAL AND METHODS The study included 30 β-thalassaemic patients aged 13.8 ±1.7 years and 30 children with constitutional short stature as controls. Anthropometric measurements (basal and after 6 months), thyroid profile, insulin-like growth factor-1 (IGF-1) and GH provocation by 2 tests were carried out. Eight patients with inadequate GH response to both clonidine and ITT were given L-carnitine treatment for 6 months. They were re-evaluated (clinically, anthropometrically and in the laboratory by doing GH stimulation test) after 6 months of therapy. RESULTS Twelve (40%) patients had sub-clinical hypothyroidism and 10 (33.3%) had growth hormone deficiency (GHD). Peak GH and growth velocity (cm and standard deviation score [SDS]) were significantly lower while weight (SDS) and weight/height SDS were significantly higher than in patients with constitutional short stature (p < 0.05). A significant positive correlation was found between height and target height (cm). Haemoglobin levels, peak GH, IGF-1 and growth velocity (cm & SDS) were significantly higher and the number of blood transfusions was significantly lower in GH deficiency patients after L-carnitine treatment (p < 0.05). Delta changes were higher in height (cm & SDS), estimated mature height and sitting height and lower in target height - height (SDS and cm) six months after L-carnitine treatment in β-thalassaemic patients with GHD (p < 0.05). CONCLUSIONS Growth hormone deficiency is an aetiological factor in thalassaemic patients with short stature. L-carnitine can promote GH secretion and growth.
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Affiliation(s)
| | | | - Fatma El Mougy
- Department of Clinical and Chemical Pathology, Cairo University, Cairo, Egypt
| | - Esmat Abd El Gafar
- Department of Clinical and Chemical Pathology, National Research Centre, Cairo, Egypt
| | - Hend Samir
- Department of Paediatrics, Cairo University, Cairo, Egypt
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Hauton D, Coney AM, Egginton S. Both substrate availability and utilisation contribute to the defence of core temperature in response to acute cold. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:514-22. [PMID: 19712745 DOI: 10.1016/j.cbpa.2009.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/18/2009] [Accepted: 08/18/2009] [Indexed: 11/28/2022]
Abstract
Acute cooling significantly increases energy demand in non-hibernators for the defence of core temperature but the contribution of the liver to thermogenesis is poorly understood. A two-tracer method to estimate lipid metabolism in cold-naïve control (CON) and cold-acclimated (CA) rats was employed to quantify hepatic rates of fat metabolism. Both fenofibrate, to increase liver mass and fat oxidation and dichloroacetate (DCA) to inhibit fat oxidation were used to alter lipid metabolism in CON animals. Following acute cooling, CA led to a doubling of the time to reach a core temperature 25 degrees C (P<0.001), whereas DCA treatment decreased time of cooling (P<0.01). DCA-treatment increased the gradient of Arrhenius-transformed rate-pressure product (P<0.01). CA increased both palmitate uptake (P<0.001) and beta-oxidation (P<0.01) whilst DCA treatment decreased uptake (P<0.01) and beta-oxidation (P<0.05). Tissue-specific estimates of metabolism revealed that CA led to a 12-fold increase in beta-oxidation for brown adipose tissue (P<0.001) whilst fenofibrate halved beta-oxidation in the liver (P<0.01) despite doubling the liver mass (P<0.001) and DCA decreased hepatic beta-oxidation to 15% of control levels. Taken together, these results suggest that the liver has minimal contribution to thermogenesis in the rat, with brown adipose tissue significantly increasing both fat uptake and oxidation in response to CA.
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Affiliation(s)
- David Hauton
- School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
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Cheng Y, Hauton D. Cold acclimation induces physiological cardiac hypertrophy and increases assimilation of triacylglycerol metabolism through lipoprotein lipase. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:618-26. [PMID: 18722549 PMCID: PMC2568868 DOI: 10.1016/j.bbalip.2008.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 07/15/2008] [Accepted: 07/15/2008] [Indexed: 12/24/2022]
Abstract
The contribution of triacylglycerol to energy provision in the hypertrophied heart, mediated through lipoprotein lipase (LPL) is largely unknown and the contribution of very-low-density lipoprotein (VLDL) receptor to control of LPL presentation at the endothelium is unclear. For isolated perfused rat hearts, cold acclimation (CA) induced volume-overload hypertrophy, with decreased developed pressure (P < 0.01), increased end-diastolic volume of the left ventricle (P < 0.001) and a loss of contractile reserve in response to dobutamine challenge (P < 0.01). Oleate utilisation by perfused hearts was unchanged by CA, however uptake of intralipid emulsion increased 3-fold (P < 0.01). CA increased the proportion of lipid deposited in tissue lipids from 10% in euthermic controls to 40% (P < 0.01) although the overall contribution of individual lipid classes was unaffected. Cold acclimation significantly increased heparin-releasable LPL (P < 0.05) and tissue residual LPL (P < 0.01). Western blot analysis indicated preserved expression of proteins coding for SERCA2, muscle-CPT1 and VLDL-receptor following CA, while AMPKα2 and phospho-AMPKα2 were unaffected. These observations indicate that for physiological hypertrophy AMPK phosphorylation does not mediate the enhanced translocation of LPL to cardiac endothelium.
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Affiliation(s)
- Y Cheng
- Department of Physiology, Division of Medical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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Jeyapalan AS, Orellana RA, Suryawan A, O'Connor PMJ, Nguyen HV, Escobar J, Frank JW, Davis TA. Glucose stimulates protein synthesis in skeletal muscle of neonatal pigs through an AMPK- and mTOR-independent process. Am J Physiol Endocrinol Metab 2007; 293:E595-603. [PMID: 17551002 DOI: 10.1152/ajpendo.00121.2007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Skeletal muscle protein synthesis is elevated in neonates in part due to an enhanced response to the rise in insulin and amino acids after eating. In vitro studies suggest that glucose plays a role in protein synthesis regulation. To determine whether glucose, independently of insulin and amino acids, is involved in the postprandial rise in skeletal muscle protein synthesis, pancreatic-substrate clamps were performed in neonatal pigs. Insulin secretion was inhibited with somatostatin and insulin was infused to reproduce fasting or fed levels, while glucose and amino acids were clamped at fasting or fed levels. Fractional protein synthesis rates and translational control mechanisms were examined. Raising glucose alone increased protein synthesis in fast-twitch glycolytic muscles but not in other tissues. The response in muscle was associated with increased phosphorylation of protein kinase B (PKB) and enhanced formation of the active eIF4E.eIF4G complex but no change in phosphorylation of AMP-activated protein kinase (AMPK), tuberous sclerosis complex 2 (TSC2), mammalian target of rapamycin (mTOR), 4E-binding protein-1 (4E-BP1), ribosomal protein S6 kinase (S6K1), or eukaryotic elongation factor 2 (eEF2). Raising glucose, insulin, and amino acids increased protein synthesis in most tissues. The response in muscle was associated with phosphorylation of PKB, mTOR, S6K1, and 4E-BP1 and enhanced eIF4E.eIF4G formation. The results suggest that the postprandial rise in glucose, independently of insulin and amino acids, stimulates protein synthesis in neonates, and this response is specific to fast-twitch glycolytic muscle and occurs by AMPK- and mTOR-independent pathways.
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Affiliation(s)
- Asumthia S Jeyapalan
- United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center and Pediatric Critical Care Section, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA
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Damon M, Louveau I, Lefaucheur L, Lebret B, Vincent A, Leroy P, Sanchez MP, Herpin P, Gondret F. Number of intramuscular adipocytes and fatty acid binding protein-4 content are significant indicators of intramuscular fat level in crossbred Large White × Duroc pigs1. J Anim Sci 2006; 84:1083-92. [PMID: 16612010 DOI: 10.2527/2006.8451083x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Intramuscular fat content is generally associated with improved sensory quality and better acceptability of fresh pork. However, conclusive evidence is still lacking for the biological mechanisms underlying i.m. fat content variability in pigs. The current study aimed to determine whether variations in i.m. fat content of longissimus muscle are related to i.m. adipocyte cellularity, lipid metabolism, or contractile properties of the whole muscle. To this end, crossbred (Large White x Duroc) pigs exhibiting either a high (2.82 +/- 0.38%, HF) or a low (1.15 +/- 0.14%, LF) lipid content in LM biopsies at 70 kg of BW were further studied at 107 +/- 7 kg of BW. Animals grew at the same rate, but HF pigs at slaughter presented fatter carcasses than LF pigs (P = 0.04). The differences in i.m. fat content between the 2 groups were mostly explained by variation in i.m. adipocyte number (+127% in HF compared with LF groups, P = 0.005). Less difference (+13% in HF compared with LF groups, P = 0.057) was noted in adipocyte diameter, and no significant variation was detected in whole-muscle lipogenic enzyme activities (acetyl-CoA carboxylase, P = 0.9; malic enzyme, P = 0.35; glucose-6-phosphate dehydrogenase, P = 0.75), mRNA levels of sterol-regulatory element binding protein-1 (P = 0.6), or diacylglycerol acyltransferase 1 (P = 0.6). Adipocyte fatty acid binding protein (FABP)-4 protein content in whole LM was 2-fold greater in HF pigs than in LF pigs (P = 0.05), and positive correlation coefficients were found between the FABP-4 protein level and adipocyte number (R2 = 0.47, P = 0.02) and lipid content (R2 = 0.58, P = 0.004). Conversely, there was no difference between groups relative to FABP-3 mRNA (P = 0.46) or protein (P = 0.56) levels, oxidative enzymatic activities (citrate synthase, P = 0.9; beta-hydroxyacyl-CoA dehydrogenase, P = 0.7), mitochondrial (P = 0.5) and peroxisomal (P = 0.12) oxidation rates of oleate, mRNA levels of genes involved in fatty acid oxidation (carnitine-palmitoyl-transferase 1, P = 0.98; peroxisome proliferator-activated receptor delta, P = 0.73) or energy expenditure (uncoupling protein 2, P = 0.92; uncoupling protein 3, P = 0.84), or myosin heavy-chain mRNA proportions (P > 0.49). The current study suggests that FABP-4 protein content may be a valuable marker of lipid accretion in LM and that i.m. fat content and myofiber type composition can be manipulated independently.
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Affiliation(s)
- M Damon
- Unité Mixte de Recherches Systèmes d'Elevage Nutrition Animale et Humaine, Institut National de la Recherche Agronomique, 35590 Saint Gilles, France.
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Hauton D, Richards SB, Egginton S. The role of the liver in lipid metabolism during cold acclimation in non-hibernator rodents. Comp Biochem Physiol B Biochem Mol Biol 2006; 144:372-81. [PMID: 16730468 DOI: 10.1016/j.cbpb.2006.03.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2006] [Revised: 03/30/2006] [Accepted: 03/31/2006] [Indexed: 11/24/2022]
Abstract
Cold exposure increases the demand for energy substrates. Cold acclimation of rats led to a 3-fold increase in fatty acid (FA) beta-oxidation (P<0.01) for ex vivo livers perfused at 37 degrees C. This increase was preserved following perfusion at 25 degrees C (P<0.001). In vitro measurement of absolute rates of hepatic beta-oxidation revealed no significant difference following cold acclimation, implying changes in fatty acid flux through beta-oxidation rather than increased oxidation capacity. Total FA uptake was increased one-third following perfusion at 25 degrees C (P<0.001) and cold acclimation (P<0.05) and cold acclimation led to diversion of tissue FA from storage to beta-oxidation (P<0.01). In separate experiments, in vivo hepatic lipogenesis rates for saponifiable lipids doubled (P<0.01) and cholesterol synthesis increased one-third (P<0.001). Taken together these data suggest the oxidation and synthesis of lipids occur simultaneously in hepatic tissue possibly to increase prevailing tissue FA concentrations and to generate heat through increased metabolic flux rates.
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Affiliation(s)
- David Hauton
- Department of Physiology, Division of Medical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
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Gondret F, Damon M, Jadhao SB, Houdebine LM, Herpin P, Hocquette JF. Age-related changes in glucose utilization and fatty acid oxidation. J Muscle Res Cell Motil 2004; 25:405-10. [PMID: 15548870 DOI: 10.1007/s10974-004-2768-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The optimal utilization of energy substrates in muscle fibers is of primary importance for muscle contraction and whole body physiology. This study aimed to investigate the age-related changes in some indicators of glucose catabolism and fatty acid oxidation in muscles of growing rabbits. Longissimus lumborum (fast-twitch, LL) and semimembranosus proprius (slow-twitch, SMP) muscles were collected at 10 or 20 weeks of age ( n=6 per age). Glucose transporter GLUT4 content was investigated by immunoblot assay. Activity levels of five enzymes were measured: lactate dehydrogenase (LDH) and phosphofructokinase (PFK) for glycolysis; citrate synthase (CS), isocitrate dehydrogenase (ICDH) and -3-hydroxyacyl-coenzyme A dehydrogenase (HAD) for oxidation. Mitochondrial and peroxisomal oxidation rates were assessed on fresh homogenates using [1-14C]-oleate as substrate. At both ages, mitochondrial and peroxisomal oxidations rates, as well as activities of oxidative enzymes were higher in SMP than in LL. In both muscles, the apparent rate of fatty acid oxidation by the mitochondria did not differ between the two ages. However, a decrease in the activities of the three oxidative enzymes was observed in LL, whereas activities of CS and HAD and peroxisomal oxidation rate of oleate increased between the two ages in SMP muscle. In both muscles, LDH activity increased between 10 and 20 weeks, without variations in glucose uptake (GLUT4 transporter content) and in the first step of glucose utilization (PFK activity). In conclusion, mitochondrial oxidation rate of fatty acids and activities of selected mitochondrial enzymes were largely unrelated. Moreover, regulation of energy metabolism with advancing age differed between muscle types.
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Affiliation(s)
- Florence Gondret
- INRA, Unité Mixte de Recherches sur le Veau et le Porc, Saint Gilles, France.
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