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Smith L, Martin C, Lasserre F, Engelmann B, Klément W, Fougerat A, Polizzi A, Canlet C, Rolle-Kampczyk U, Von Bergen M, Lippi Y, Guillou H, Loiseau N, Payastre L, Ellero-Simatos S. Impact d’une exposition alimentaire chronique au glyphosate à des doses de référence sur le microbiote intestinal et le métabolisme énergétique chez la souris. NUTR CLIN METAB 2021. [DOI: 10.1016/j.nupar.2021.01.110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Smati S, Régnier M, Fougeray T, Polizzi A, Fougerat A, Lasserre F, Lukowicz C, Tramunt B, Guillaume M, Burnol AF, Postic C, Wahli W, Montagner A, Gourdy P, Guillou H. Regulation of hepatokine gene expression in response to fasting and feeding: Influence of PPAR-α and insulin-dependent signalling in hepatocytes. Diabetes Metab 2019; 46:129-136. [PMID: 31163275 DOI: 10.1016/j.diabet.2019.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 05/10/2019] [Accepted: 05/19/2019] [Indexed: 12/21/2022]
Abstract
AIM In hepatocytes, the peroxisome proliferator-activated receptor (PPAR)-α and insulin receptor (IR) are critical for transcriptional responses to fasting and feeding, respectively. The present report analyzes the effects of nutritional status (fasting vs feeding) on the expression of a large panel of hepatokines in hepatocyte-specific PPAR-α (Pparαhep-/-) and IR (IRhep-/-) null mice. METHODS Pparαhep-/- and IRhep-/- mice, and their wild-type littermates, were subjected to fasting or feeding metabolic challenges, then analyzed for hepatokine gene expression. Experiments were conducted in mice of both genders. RESULTS Our data confirmed that PPAR-α is essential for regulating fasting-induced Fgf21 and Angptl4 expression. In mice lacking PPAR-α, fasting led to increased Igfbp1 and Gdf15 gene expression. In the absence of hepatic IR, feeding induced overexpression of Igfbp1, follistatin (Fst) and adropin (Enho), and reduced activin E (Inhbe) expression. Gender had only a modest influence on hepatokine gene expression in the liver. CONCLUSION The present results highlight the potential roles of hepatokines as a class of hormones that substantially influence nutritional regulation in both female and male mice.
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Affiliation(s)
- S Smati
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France; UMR 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Université de Toulouse, Institut National de la Santé et de la Recherche Médicale (Inserm), 31000 Toulouse, France
| | - M Régnier
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - T Fougeray
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - A Polizzi
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - A Fougerat
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - F Lasserre
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - C Lukowicz
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France
| | - B Tramunt
- UMR 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Université de Toulouse, Institut National de la Santé et de la Recherche Médicale (Inserm), 31000 Toulouse, France
| | - M Guillaume
- UMR 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Université de Toulouse, Institut National de la Santé et de la Recherche Médicale (Inserm), 31000 Toulouse, France
| | - A-F Burnol
- Institut National de la Santé et de la Recherche Médicale (INSERM U1016), Institut Cochin, 75014 Paris, France; CNRS UMR 8104, 75014 Paris, France; University of Paris Descartes, Sorbonne Paris Cité, 75005 Paris, France
| | - C Postic
- Institut National de la Santé et de la Recherche Médicale (INSERM U1016), Institut Cochin, 75014 Paris, France; CNRS UMR 8104, 75014 Paris, France; University of Paris Descartes, Sorbonne Paris Cité, 75005 Paris, France
| | - W Wahli
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France; Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, 11 Mandalay Road, 308232 Singapore, Singapore; Center for Integrative Genomics, Université de Lausanne, Le Génopode, Lausanne, Switzerland
| | - A Montagner
- UMR 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Université de Toulouse, Institut National de la Santé et de la Recherche Médicale (Inserm), 31000 Toulouse, France
| | - P Gourdy
- UMR 1048, Institute of Metabolic and Cardiovascular Diseases (I2MC), Université de Toulouse, Institut National de la Santé et de la Recherche Médicale (Inserm), 31000 Toulouse, France; Diabetology Department, CHU de Toulouse, 31000 Toulouse, France
| | - H Guillou
- UMR 1331, Institut National de la Recherche Agronomique (INRA), Toxalim (Research Centre in Food Toxicology), 180, chemin de Tournefeuille, 1331 Toulouse, France.
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Montagner A, Iroz A, Benhamed F, Polizzi A, Anthony E, Régnier M, Lukowicz C, Fouché E, Lippi Y, Wahli W, Postic C, Guillou H. Rôle de PPARα hépatocytaire dans le contrôle central de la préférence au sucre par FGF21. NUTR CLIN METAB 2018. [DOI: 10.1016/j.nupar.2018.09.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Smati S, Polizzi A, Marrot A, Régnier M, Lukowicz C, Lasserre F, Saati T, Montagner A, Gourdy P, Guillou H. Influence du genre dans la sensibilité à la stéatose et de la stéato-hépatite non alcoolique. NUTR CLIN METAB 2018. [DOI: 10.1016/j.nupar.2018.09.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Montagner A, Michel G, Fouché E, Régnier M, Polizzi A, Lukowicz C, Amiel A, Lasserre F, Naylies C, Canlet C, Tremblay-Franco M, Debrauwer L, Lippi Y, Wahli W, Guillou H. PPARβ hépatocytaire est un senseur circadien des acides gras alimentaires. NUTR CLIN METAB 2017. [DOI: 10.1016/j.nupar.2017.06.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Barquissau V, Beuzelin D, Pisani DF, Beranger GE, Mairal A, Montagner A, Roussel B, Tavernier G, Marques MA, Moro C, Guillou H, Amri EZ, Langin D. White-to-brite conversion in human adipocytes promotes metabolic reprogramming towards fatty acid anabolic and catabolic pathways. Mol Metab 2016; 5:352-365. [PMID: 27110487 PMCID: PMC4837301 DOI: 10.1016/j.molmet.2016.03.002] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 03/13/2016] [Indexed: 12/29/2022] Open
Abstract
Objective Fat depots with thermogenic activity have been identified in humans. In mice, the appearance of thermogenic adipocytes within white adipose depots (so-called brown-in-white i.e., brite or beige adipocytes) protects from obesity and insulin resistance. Brite adipocytes may originate from direct conversion of white adipocytes. The purpose of this work was to characterize the metabolism of human brite adipocytes. Methods Human multipotent adipose-derived stem cells were differentiated into white adipocytes and then treated with peroxisome proliferator-activated receptor (PPAR)γ or PPARα agonists between day 14 and day 18. Gene expression profiling was determined using DNA microarrays and RT-qPCR. Variations of mRNA levels were confirmed in differentiated human preadipocytes from primary cultures. Fatty acid and glucose metabolism was investigated using radiolabelled tracers, Western blot analyses and assessment of oxygen consumption. Pyruvate dehydrogenase kinase 4 (PDK4) knockdown was achieved using siRNA. In vivo, wild type and PPARα-null mice were treated with a β3-adrenergic receptor agonist (CL316,243) to induce appearance of brite adipocytes in white fat depot. Determination of mRNA and protein levels was performed on inguinal white adipose tissue. Results PPAR agonists promote a conversion of white adipocytes into cells displaying a brite molecular pattern. This conversion is associated with transcriptional changes leading to major metabolic adaptations. Fatty acid anabolism i.e., fatty acid esterification into triglycerides, and catabolism i.e., lipolysis and fatty acid oxidation, are increased. Glucose utilization is redirected from oxidation towards glycerol-3-phophate production for triglyceride synthesis. This metabolic shift is dependent on the activation of PDK4 through inactivation of the pyruvate dehydrogenase complex. In vivo, PDK4 expression is markedly induced in wild-type mice in response to CL316,243, while this increase is blunted in PPARα-null mice displaying an impaired britening response. Conclusions Conversion of human white fat cells into brite adipocytes results in a major metabolic reprogramming inducing fatty acid anabolic and catabolic pathways. PDK4 redirects glucose from oxidation towards triglyceride synthesis and favors the use of fatty acids as energy source for uncoupling mitochondria. PPARγ and α agonists induce conversion of human white into brite adipocytes. Fatty acid anabolism and catabolism are activated in human brite adipocytes. Glucose use in brite adipocytes is redirected from oxidation to glyceroneogenesis. PDK4 induction is responsible for the shift from glucose to fatty acid oxidation.
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Affiliation(s)
- V Barquissau
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - D Beuzelin
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - D F Pisani
- University of Nice Sophia Antipolis, Nice, France; CNRS, iBV, UMR 7277, Nice, France; INSERM, iBV, U 1091, Nice, France
| | - G E Beranger
- University of Nice Sophia Antipolis, Nice, France; CNRS, iBV, UMR 7277, Nice, France; INSERM, iBV, U 1091, Nice, France
| | - A Mairal
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - A Montagner
- University of Toulouse, Paul Sabatier University, France; INRA, UMR 1331, TOXALIM, Toulouse, France
| | - B Roussel
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - G Tavernier
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - M-A Marques
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - C Moro
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France
| | - H Guillou
- University of Toulouse, Paul Sabatier University, France; INRA, UMR 1331, TOXALIM, Toulouse, France
| | - E-Z Amri
- University of Nice Sophia Antipolis, Nice, France; CNRS, iBV, UMR 7277, Nice, France; INSERM, iBV, U 1091, Nice, France
| | - D Langin
- INSERM, UMR 1048, Institute of Metabolic and Cardiovascular Diseases, Toulouse, France; University of Toulouse, Paul Sabatier University, France; Toulouse University Hospitals, Laboratory of Clinical Biochemistry, Toulouse, France.
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Gobbetti T, Ducheix S, le Faouder P, Perez T, Riols F, Boue J, Bertrand-Michel J, Dubourdeau M, Guillou H, Perretti M, Vergnolle N, Cenac N. Protective effects of n-6 fatty acids-enriched diet on intestinal ischaemia/reperfusion injury involve lipoxin A4 and its receptor. Br J Pharmacol 2014; 172:910-23. [PMID: 25296998 DOI: 10.1111/bph.12957] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 09/12/2014] [Accepted: 09/22/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Long-term intake of dietary fatty acids is known to predispose to chronic inflammation, but their effects on acute intestinal ischaemia/reperfusion (I/R) injury is unknown. The aim of this study was to determine the consequences of a diet rich in n-3 or n-6 polyunsaturated fatty acids (PUFA) on intestinal I/R-induced damage. EXPERIMENTAL APPROACH Mice were fed three different isocaloric diets: a balanced diet used as a control and two different PUFA-enriched diets, providing either high levels of n-3 or of n-6 PUFA. Intestinal injury was evaluated after intestinal I/R. PUFA metabolites were quantitated in intestinal tissues by LC-MS/MS. KEY RESULTS In control diet-fed mice, intestinal I/R caused inflammation and increased COX and lipoxygenase-derived metabolites compared with sham-operated animals. Lipoxin A4 (LxA4 ) was significantly and selectively increased after ischaemia. Animals fed a high n-3 diet did not display a different inflammatory profile following intestinal I/R compared with control diet-fed animals. In contrast, intestinal inflammation was decreased in the I/R group fed with high n-6 diet and level of LxA4 was increased post-ischaemia compared with control diet-fed mice. Blockade of the LxA4 receptor (Fpr2), prevented the anti-inflammatory effects associated with the n-6 rich diet. CONCLUSIONS AND IMPLICATIONS This study indicates that high levels of dietary n-6, but not n-3, PUFAs provides significant protection against intestinal I/R-induced damage and demonstrates that the endogenous production of LxA4 can be influenced by diet.
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Affiliation(s)
- T Gobbetti
- Inserm, U1043, Toulouse, France; CNRS, U5282, Toulouse, France; Centre de Physiopathologie de Toulouse Purpan (CPTP), Université de Toulouse, Université Paul Sabatier, Toulouse, France; WHRI, Queen Mary University, London, UK
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Berger J, Moreau F, Prieur X, Costet P, Lasserre F, Guillou H, Cariou B, Le May C. Diosgenin induces trans-intestinal cholesterol excretion in ldl receptor deficient females. Atherosclerosis 2014. [DOI: 10.1016/j.atherosclerosis.2014.05.280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Postic C, Iroz A, Benhamed F, Alexandra M, Guillou H, Girard J. O24 Régulation différentielle de FGF21 dans le foie par les facteurs ChREBP et PPARα au cours de la transition jeûne-réalimentation. Diabetes & Metabolism 2014. [DOI: 10.1016/s1262-3636(14)72198-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Marmugi A, Lasserre F, Montagner A, Polizzi A, Ducheix S, Guillou H, Mselli-Lakhal L. O45 L’adiponutrine, un nouveau marqueur de la stéatose hépatique est activé par le récepteur nucléaire aux androstanes CAR. NUTR CLIN METAB 2013. [DOI: 10.1016/s0985-0562(13)70317-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Montagner A, Polizzi A, Fouche E, Ducheix S, Lasserre F, Lippi Y, Canlet C, Franco-Tremblay M, Lakhal L, Loiseau N, Wahli W, Guillou H. O15 Effet de l’invalidation hépato-spécifique de PPARalpha sur le métabolisme des lipides et sur la régulation de FGF21. NUTR CLIN METAB 2013. [DOI: 10.1016/s0985-0562(13)70287-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Ramamonjisoa N, Ratiney H, Mutel E, Guillou H, Mithieux G, Pilleul F, Rajas F, Beuf O, Cavassila S. In vivo hepatic lipid quantification using MRS at 7 Tesla in a mouse model of glycogen storage disease type 1a. J Lipid Res 2013; 54:2010-22. [PMID: 23596325 DOI: 10.1194/jlr.d033399] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The assessment of liver lipid content and composition is needed in preclinical research to investigate steatosis and steatosis-related disorders. The purpose of this study was to quantify in vivo hepatic fatty acid content and composition using a method based on short echo time proton magnetic resonance spectroscopy (MRS) at 7 Tesla. A mouse model of glycogen storage disease type 1a with inducible liver-specific deletion of the glucose-6-phosphatase gene (L-G6pc(-/-)) mice and control mice were fed a standard diet or a high-fat/high-sucrose (HF/HS) diet for 9 months. In control mice, hepatic lipid content was found significantly higher with the HF/HS diet than with the standard diet. As expected, hepatic lipid content was already elevated in L-G6pc(-/-) mice fed a standard diet compared with control mice. L-G6pc(-/-) mice rapidly developed steatosis which was not modified by the HF/HS diet. On the standard diet, estimated amplitudes from olefinic protons were found significantly higher in L-G6pc(-/-) mice compared with that in control mice. L-G6pc(-/-) mice showed no noticeable polyunsaturation from diallylic protons. Total unsaturated fatty acid indexes measured by gas chromatography were in agreement with MRS measurements. These results showed the great potential of high magnetic field MRS to follow the diet impact and lipid alterations in mouse liver.
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Affiliation(s)
- Nirilanto Ramamonjisoa
- Université de Lyon, CREATIS, CNRS UMR 5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Villeurbanne, France
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Perret G, Chiang PT, Lacornerie T, Kumemura M, Lafitte N, Guillou H, Jalabert L, Lartigau E, Fujii T, Cleri F, Fujita H, Collard D. Silicon Nanotweezers with a microfluidic cavity for the real time characterization of DNA damage under therapeutic radiation beams. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:6820. [PMID: 24111310 DOI: 10.1109/embc.2013.6611123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the biomechanical characterization of λ-DNA bundle exposed to a therapeutic radiation beam by silicon Nanotweezers. The micromechanical device endures the harsh environment of radiation beams, and still retains molecular-level detection accuracy. The real-time DNA bundle degradation is observed in terms of biomechanical stiffness and viscosity reduction, both in air and in solution. These results pave the way for both fundamental and clinical studies of DNA degradation mechanisms under ionizing radiation for improved tumor treatment.
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Abstract
The thermodynamic treatment of the glass transition remains an issue of intense debate. When associated with the formalism of non-equilibrium thermodynamics, the lattice-hole theory of liquids can provide new insight in this direction, as has been shown by Schmelzer and Gutzow [J. Chem. Phys. 125, 184511 (2006)], by Möller et al. [J. Chem. Phys. 125, 094505 (2006)], and more recently by Tropin et al. [J. Non-Cryst. Solids 357, 1291 (2011); ibid. 357, 1303 (2011)]. Here, we employ a similar approach. We include pressure as an additional variable, in order to account for the freezing-in of structural degrees of freedom upon pressure increase. Second, we demonstrate that important terms concerning first order derivatives of the affinity-driving-force with respect to temperature and pressure have been previously neglected. We show that these are of crucial importance in the approach. Macroscopic non-equilibrium thermodynamics is used to enlighten these contributions in the derivation of C(p),κ(T), and α(p). The coefficients are calculated as a function of pressure and temperature following different theoretical protocols, revealing classical aspects of vitrification and structural recovery processes. Finally, we demonstrate that a simple minimalist model such as the lattice-hole theory of liquids, when being associated with rigorous use of macroscopic non-equilibrium thermodynamics, is able to account for the primary features of the glass transition phenomenology. Notwithstanding its simplicity and its limits, this approach can be used as a very pedagogical tool to provide a physical understanding on the underlying thermodynamics which governs the glass transition process.
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Affiliation(s)
- J-L Garden
- Institut Néel, CNRS et UJF, 25 Avenue des Martyrs, 38042 Grenoble Cedex 09, France.
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Ducheix S, Rayah Benhamed F, Montagner A, Polizzi A, Lasserre F, Bertrand-Michel J, Lobaccaro JM, Moschetta A, Postic C, Guillou H. O04 Régulation du Liver X Receptor par le fructose et développement de la stéatose hépatique. NUTR CLIN METAB 2011. [DOI: 10.1016/s0985-0562(11)70008-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Ali O, Guillou H, Destaing O, Albigès-Rizo C, Block MR, Fourcade B. Cooperativity between integrin activation and mechanical stress leads to integrin clustering. Biophys J 2011; 100:2595-604. [PMID: 21641304 DOI: 10.1016/j.bpj.2011.03.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 03/01/2011] [Accepted: 03/17/2011] [Indexed: 12/31/2022] Open
Abstract
Integrins are transmembrane receptors involved in crucial cellular biological functions such as migration, adhesion, and spreading. Upon the modulation of integrin affinity toward their extracellular ligands by cytoplasmic proteins (inside-out signaling) these receptors bind to their ligands and cluster into nascent adhesions. This clustering results in the increase in the mechanical linkage among the cell and substratum, cytoskeleton rearrangements, and further outside-in signaling. Based on experimental observations of the distribution of focal adhesions in cells attached to micropatterned surfaces, we introduce a physical model relying on experimental numerical constants determined in the literature. In this model, allosteric integrin activation works in synergy with the stress build by adhesion and the membrane rigidity to allow the clustering to nascent adhesions independently of actin but dependent on the integrin diffusion onto adhesive surfaces. The initial clustering could provide a template to the mature adhesive structures. Predictions of our model for the organization of focal adhesions are discussed in comparison with experiments using adhesive protein microarrays.
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Affiliation(s)
- O Ali
- INSERM U823-CNRS ERL 5284, Institut Albert Bonniot, Equipe Dysad, Site Santé, La Tronche, Grenoble cedex 9, France
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Kulkarni S, Sitaru C, Jakus Z, Anderson KE, Damoulakis G, Davidson K, Hirose M, Juss J, Oxley D, Chessa TAM, Ramadani F, Guillou H, Segonds-Pichon A, Fritsch A, Jarvis GE, Okkenhaug K, Ludwig R, Zillikens D, Mocsai A, Vanhaesebroeck B, Stephens LR, Hawkins PT. PI3Kβ plays a critical role in neutrophil activation by immune complexes. Sci Signal 2011; 4:ra23. [PMID: 21487106 DOI: 10.1126/scisignal.2001617] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Neutrophils are activated by immunoglobulin G (IgG)-containing immune complexes through receptors that recognize the Fc portion of IgG (FcγRs). Here, we used genetic and pharmacological approaches to define a selective role for the β isoform of phosphoinositide 3-kinase (PI3Kβ) in FcγR-dependent activation of mouse neutrophils by immune complexes of IgG and antigen immobilized on a plate surface. At low concentrations of immune complexes, loss of PI3Kβ alone substantially inhibited the production of reactive oxygen species (ROS) by neutrophils, whereas at higher doses, similar suppression of ROS production was achieved only by targeting both PI3Kβ and PI3Kδ, suggesting that this pathway displays stimulus strength-dependent redundancy. Activation of PI3Kβ by immune complexes involved cooperation between FcγRs and BLT1, the receptor for the endogenous proinflammatory lipid leukotriene B₄. Coincident activation by a tyrosine kinase-coupled receptor (FcγR) and a heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptor (BLT1) may provide a rationale for the preferential activation of the β isoform of PI3K. PI3Kβ-deficient mice were highly protected in an FcγR-dependent model of autoantibody-induced skin blistering and were partially protected in an FcγR-dependent model of inflammatory arthritis, whereas combined deficiency of PI3Kβ and PI3Kδ resulted in near-complete protection in the latter case. These results define PI3Kβ as a potential therapeutic target in inflammatory disease.
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Affiliation(s)
- Suhasini Kulkarni
- Inositide Laboratory, The Babraham Institute, Cambridge CB22 3AT, UK
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Demeure O, Lecerf F, Duby C, Desert C, Ducheix S, Guillou H, Lagarrigue S. Regulation of LPCAT3 by LXR. Gene 2011; 470:7-11. [DOI: 10.1016/j.gene.2010.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 09/01/2010] [Accepted: 09/06/2010] [Indexed: 10/19/2022]
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19
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Demeure O, Duby C, Desert C, Assaf S, Hazard D, Guillou H, Lagarrigue S. Liver X receptor α regulates fatty acid synthase expression in chicken. Poult Sci 2009; 88:2628-35. [DOI: 10.3382/ps.2009-00258] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Blavy P, Gondret F, Guillou H, Lagarrigue S, Martin PGP, van Milgen J, Radulescu O, Siegel A. A minimal model for hepatic fatty acid balance during fasting: application to PPAR alpha-deficient mice. J Theor Biol 2009; 261:266-78. [PMID: 19635486 DOI: 10.1016/j.jtbi.2009.07.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2009] [Revised: 06/25/2009] [Accepted: 07/16/2009] [Indexed: 11/17/2022]
Abstract
The purpose of this study is to identify the hierarchy of importance amongst pathways involved in fatty acid (FA) metabolism and their regulators in the control of hepatic FA composition. A modeling approach was applied to experimental data obtained during fasting in PPARalpha knockout (KO) mice and wild-type mice. A step-by-step procedure was used in which a very simple model was completed by additional pathways until the model fitted correctly the measured quantities of FA in the liver. The resulting model included FA uptake by the liver, FA oxidation, elongation and desaturation of FA, which were found active in both genotypes during fasting. From the model analysis we concluded that PPARalpha had a strong effect on FA oxidation. There were no indications that this effect changes during the fasting period, and it was thus considered to be constant. In PPARalpha KO mice, FA uptake was identified as the main pathway responsible for FA variation in the liver. The models showed that FA were oxidized at a constant and small rate, whereas desaturation of FA also occurred during fasting. The latter observation was rather unexpected, but was confirmed experimentally by the measurement of delta-6-desaturase mRNA using real-time quantitative PCR (QPCR). These results confirm that mathematical models can be a useful tool in identifying new biological hypotheses and nutritional routes in metabolism.
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Affiliation(s)
- P Blavy
- INRA, UMR 1079 Systèmes d'Elevage, Nutrition Animale et Humaine, F-35590 Saint Gilles, France.
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Garden JL, Richard J, Guillou H. Erratum: “Temperature of systems out of thermodynamic equilibrium” [J. Chem. Phys. 129, 044508 (2008)]. J Chem Phys 2008. [DOI: 10.1063/1.2982513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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22
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Abstract
Two phenomenological approaches are currently used in the study of the vitreous state. One is based on the concept of fictive temperature introduced by Tool [J. Res. Natl. Bur. Stand. 34, 199 (1945)] and recently revisited by Nieuwenhuizen [Phys. Rev. Lett. 80, 5580 (1998)]. The other is based on the thermodynamics of irreversible processes initiated by De Donder at the beginning of the last century [L'Affinite (Gauthier-Villars, Paris, 1927)] and recently used by Moller et al. for a thorough study of the glass transition [J. Chem. Phys. 125, 094505 (2006)]. This latter approach leads to the possibility of describing the glass transition by means of the freezing-in of one or more order parameters connected to the internal structural degrees of freedom involved in the vitrification process. In this paper, the equivalence of the two preceding approaches is demonstrated, not only for glasses but in a very general way for any system undergoing an irreversible transformation. This equivalence allows the definition of an effective temperature for all systems departed from equilibrium generating a positive amount of entropy. In fact, the initial fictive temperature concept of Tool leads to the generalization of the notion of temperature for systems out of thermodynamic equilibrium, for which glasses are just particular cases.
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Affiliation(s)
- J-L Garden
- Institut Néel, CNRS et Université Joseph Fourier, BP 166, 38042 Grenoble Cedex 9, France.
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Carracedo JC, Badiola ER, Guillou H, De la Nuez J, Pérez Torrado FJ. Geología y vulcanología de La Palma y El Hierro, Canarias Occidentales. ACTA ACUST UNITED AC 2007. [DOI: 10.3989/egeol.01575-6134] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Carracedo JC, Singer B, Jicha B, Guillou H, Rodríguez Badiola E, Meco J, Pérez Torrado FJ, Gimeno D, Socorro S, Láinez A. La erupción y el tubo volcánico del Volcán Corona (Lanzarote, Islas Canarias). ACTA ACUST UNITED AC 2007. [DOI: 10.3989/egeol.03595-6104] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Abstract
A single gene encoding a δ6-desaturase (FADS2) has been isolated and characterized in mammalian species. This δ6-desaturase plays a major role in the biosynthesis of PUFAs (polyunsaturated fatty acids). It catalyses the rate-limiting desaturation of linoleic acid (C18:2n−6) and α-linolenic acid (C18:3n−3) required for the biosynthesis of long-chain PUFAs. Moreover, recent studies have provided strong evidence that this δ6-desaturase also acts on 24-carbon PUFAs of both the n−6 and n−3 series. Another substrate of this δ6-desaturase has been identified through complementary works from different investigators. This δ6-desaturase acts on a saturated fatty acid, palmitic acid (C16:0), leading to the newly characterized biosynthesis of hexadecenoic acid (C16:1n−10) or sapienate.
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Affiliation(s)
- H Guillou
- Laboratoire de Biochimie, INRA-ENSA, 65 rue de Saint-Brieuc, CS84215, 35042 Rennes cedex, France
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Singer BS, Relle MK, Hoffman KA, Battle A, Laj C, Guillou H, Carracedo JC. Ar/Ar ages from transitionally magnetized lavas on La Palma, Canary Islands, and the geomagnetic instability timescale. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jb001613] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- B. S. Singer
- Department of Geology and Geophysics; University of Wisconsin-Madison; Madison Wisconsin USA
| | - M. K. Relle
- Department of Geology and Geophysics; University of Wisconsin-Madison; Madison Wisconsin USA
| | - K. A. Hoffman
- Physics Department; California Polytechnic State University; San Luis Obispo California USA
| | - A. Battle
- Physics Department; California Polytechnic State University; San Luis Obispo California USA
| | - C. Laj
- Laboratoire des Sciences du Climat et de l'Environnement; CEA-CNRS; Gif-sur-Yvette France
| | - H. Guillou
- Laboratoire des Sciences du Climat et de l'Environnement; CEA-CNRS; Gif-sur-Yvette France
| | - J. C. Carracedo
- Estación Volcanológica de Canarias; Instituto de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Cientificas; La Laguna, Tenerife Spain
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Guillou H, Miranda G, Pelissier JP. Hydrolysis of beta-casein by gastric proteases. I. Comparison of proteolytic action of bovine chymosin and pepsin A. Int J Pept Protein Res 1991; 37:494-501. [PMID: 1917306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Hydrolysis of beta A2-casein by bovine chymosin and pepsin A was performed in order to compare the hydrolysis of the two enzymes on this protein. Different conditions have been tested: pH 5.5 for 116h and pH 3.5 for 7 h [E/S = 1/100 (w/w)] for chymosin. pH 3.0 for 24 h [E/S = 1/1000 (w/w)] for pepsin A. Under these conditions 17 peptides were obtained after the action of chymosin and 23 after the action of pepsin A. They corresponded respectively to the cleavage of 14 and 15 peptide bonds for chymosin and pepsin A. However, six of the peptide bonds were only hydrolyzed by chymosin and seven other bonds only by pepsin A. Our results showed a preferential splitting at the Leu-X, Ser-X, and Trp-X bonds for chymosin and Leu-X, Met-X, and Thr-X, for pepsin A. Some of the identified peptides contained sequences with possible physiological roles.
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Affiliation(s)
- H Guillou
- Milk Research Station, INRA, Jouy-en-Josas, France
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Brousse R, Barsczus HG, Bellon H, Cantagrel JM, Diraison C, Guillou H, Leotot C. Les Marquises (Polynesie francaise); volcanologie, geochronologie, discussion d'un modele de point chaud. ACTA ACUST UNITED AC 1990. [DOI: 10.2113/gssgfbull.vi.6.933] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
The activities of seven lysosomal enzymes (alpha-D-glucosidase, beta-D-galactosidase, beta-D-glucuronidase, hexosaminidase, alpha-L-fucosidase, alpha-D-mannosidase, acid phosphatases) were studied in the serum of 31 untreated patients with Graves' disease, 30 treated hyperthyroid patients whose clinical abnormalities had disappeared and whose hormones had returned to euthyroid levels, and 34 controls. The hyperthyroid state is characterized by increased serum levels of alpha-D-glucosidase, beta-D-glucuronidase, hexosaminidase and especially of alpha-L-glucosidase and alpha-D-mannosidase. In contrast, neither beta-D-galactosidase nor acid phosphatases serum levels were significantly modified. After antithyroid treatment, the activities of these enzymes returned to normal levels, except for alpha-D-mannosidase. The interpretation of these changes in serum acid hydrolases activities is controversial.
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