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Metabolic regulation of fatty acid esterification and effects of conjugated linoleic acid on glucose homeostasis in pig hepatocytes

  • J. A. Conde-Aguilera (a1), M. Lachica (a1), R. Nieto (a1) and I. Fernández-Fígares (a1)

Abstract

Conjugated linoleic acids (CLAs) are geometric and positional isomers of linoleic acid (LA) that promote growth, alter glucose metabolism and decrease body fat in growing animals, although the mechanisms are poorly understood. A study was conducted to elucidate the effects of CLA on glucose metabolism, triglyceride (TG) synthesis and IGF-1 synthesis in primary culture of porcine hepatocytes. In addition, hormonal regulation of TG and IGF-1 synthesis was addressed. Hepatocytes were isolated from piglets (n = 5, 16.0 ± 1.98 kg average body weight) by collagenase perfusion and seeded into collagen-coated T-25 flasks. Hepatocytes were cultured in William's E containing dexamethasone (10−8 and 10−7 M), insulin (10 and 100 ng/ml), glucagon (0 and 100 ng/ml) and CLA (1 : 1 mixture of cis-9, trans-11 and trans-10, cis-12 CLA, 0.05 and 0.10 mM) or LA (0.05 and 0.10 mM). Addition of CLA decreased gluconeogenesis (P < 0.05), whereas glycogen synthesis and degradation, TG synthesis and IGF-1 synthesis were not affected compared with LA. Increased concentration of fatty acids in the media decreased IGF-1 production (P < 0.001) and glycogen synthesis (P < 0.01), and increased gluconeogenesis (P < 0.001) and TG synthesis (P < 0.001). IGF-1 synthesis increased (P < 0.001) and TG synthesis decreased (P < 0.001) as dexamethasone concentration in the media rose. High insulin/glucagon increased TG synthesis. These results indicate that TG synthesis in porcine hepatocytes is hormonally regulated so that dexamethasone decreases and insulin/glucagon increases it. In addition, CLA decreases hepatic glucose production through decreased gluconeogenesis.

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Agius, L, Chowdhury, MH, Alberti, KGMM 1986. Regulation of ketogenesis, gluconeogenesis and the mitochondrial redox state by dexamethasone in hepatocytem monolayer cultures. Biochemical Journal 239, 593601.
Ajuwon, KM, Kuske, JL, Ragland, D, Adeola, O, Hancock, DL, Anderson, DB, Spurlock, ME 2003. The regulation of IGF-1 by leptin in the pig is tissue specific and independent of changes in growth hormone. Journal of Nutritional Biochemistry 14, 522530.
Amatruda, JM, Danahy, SA, Chang, CL 1983. The effects of glucocorticoids on insulin-stimulated lipogenesis in primary cultures of rat hepatocytes. Biochemical Journal 212, 135141.
Ametaj, BN, Bobe, G, Lu, Y, Young, JW, Beitz, DC 2003. Effect of sample preparation, length of time, and sample size on quantification of total lipids from bovine liver. Journal of Agricultural and Food Chemistry 51, 21052110.
Arany, E, Strain, AJ, Hube, MJ, Phillips, ID, Hill, DJ 1993. Interactive effects of nutrients and hormones on the expression of insulin-like growth factor binding protein-I (IGFBP-I) mRNA and peptide, and IGF-1 release from isolated adult rat hepatocytes. Journal of Cellular Physiology 155, 426435.
Beauloye, V, Ketelslegers, JM, Moreau, B, Thissen, JP 1999. Dexamethasone inhibits both growth hormone (GH)-induction of insulin-like growth factor-I (IGF-I) mRNA and GH receptor (GHR) mRNA levels in rat primary cultured hepatocytes. Growth Hormone & IGF Research 9, 205211.
Behnia, K, Bhatia, S, Jastromb, N, Balis, U, Sullivan, S, Yarmush, M, Toner, M 2000. Xenobiotic metabolism by cultured primary porcine hepatocytes. Tissue Engineering 6, 467479.
Boyd, RD, Whitehead, DM, Butler, WR 1985. Effect of exogenous glucagon and free fatty-acids on gluconeogenesis in fasting neonatal pigs. Journal of Animal Science 60, 659665.
Brameld, JM, Weller, PA, Saunders, JC, Buttery, PJ, Gilmour, RS 1995. Hormonal control of insulin-like growth factor-I and growth hormone receptor mRNA expression by porcine hepatocytes in culture. Journal of Endocrinology 146, 239245.
Calder, PC, Bond, JA, Harvey, DJ, Gordon, S, Newsholme, EA 1990. Uptake and incorporation of saturated and unsaturated fatty acids into macrophage lipids and their effect upon macrophage adhesion and phagocytosis. Biochemistry Journal 269, 807814.
Cantwell, H, Devery, R, Oshea, M, Stanton, C 1999. The effect of conjugated linoleic acid on the antioxidant enzyme defense system in rat hepatocytes. Lipids 34, 833839.
Christiansen, RZ 1977. Regulation of palmitate metabolism by carnitine and glucagon in hepatocytes isolated from fasted and carbohydrate refed rats. Biochimica et Biophysica Acta 488, 249262.
Clement, L, Poirier, H, Niot, I, Bocher, V, Guerre-Millo, M, Krief, S, Staels, B, Besnard, P 2002. Dietary trans-10,cis-12 conjugated linoleic acid induces hyperinsulinemia and fatty liver in the mouse. Journal of Lipid Research 43, 14001409.
Clore, JN, Glickman, PS, Helm, ST, Nestler, JE, Blackard, WG 1991. Evidence for dual control mechanism regulating hepatic glucose output in nondiabetic men. Diabetes 40, 10331040.
Corl, BA, Oliver, SAM, Lin, X, Oliver, WT, Ma, Y, Harrell, RJ, Odle, J 2008. Conjugated linoleic acid reduces body fat accretion and lipogenic gene expression in neonatal pigs fed low- or high-fat formulas. Journal of Nutrition 138, 449454.
Diamant, S, Shafrir, E 1975. Modulation of the activity of insulin-dependent enzymes of lipogenesis by glucocorticoids. European Journal of Biochemistry 53, 541546.
Duée, PH, Pégorier, JP, Peret, J, Girard, J 1985. Separate effects of fatty acid oxidation and glucagon on gluconeogenesis in isolated hepatocytes from newborn pigs. Biology of the Neonate 47, 7783.
Duerden, JM, Gibbons, GF 1990. Storage, mobilization and secretion of cytosolic triacylglycerol in hepatocyte cultures. The role of insulin. Biochemistry Journal 272, 583587.
Dugan, MER, Aalhus, JL, Schaefer, AL, Kramer, JKG 1997. The effect of conjugated linoleic acid on fat to lean repartitioning and feed conversion in pigs. Canadian Journal of Animal Science 77, 723725.
Dunger, D, Yuen, K, Ong, K 2004. Insulin-like growth factor I and impaired glucose tolerance. Hormone Research 62, 101107.
Fenton, JP, Roehrig, KL, Mahan, DC, Corley, JR 1985. Effect of swine weaning age on body fat and lipogenic activity in liver and adipose tissue. Journal of Animal Science 60, 190199.
Fernández-Fígares, I, Shannon, AE, Wray-Cahen, D, Caperna, TJ 2004. The role of insulin, glucagon, dexamethasone and leptin in the regulation of ketogenesis and glycogen storage in primary cultures of porcine hepatocytes prepared from growing pigs. Domestic Animal Endocrinology 27, 125140.
Fernández-Fígares, I, Lachica, M, Nieto, R, Aguilera, JF 2007. Serum profile of metabolites and hormones of growing Iberian gilts fed diets supplemented with betaine, conjugated linoleic acid or both2nd International Symposium on Energy and Protein Metabolism and Nutrition (ed. I Ortigues-Marty, N Miraux, W Brand-Williams), Vichy, France, pp. 385386. Wageningen Academic Publishers, Wageningen, The Netherlands.
Ferré, P, Satabin, P, El Manoubi, L, Callikan, S, Girard, J 1981. Relationship between ketogenesis and gluconeogenesis in isolated hepatocytes from newborn rats. Biochemistry Journal 200, 429433.
Gondret, F, Ferré, P, Dugail, I 2001. ADD-1/SREBP-1 is a major determinant of tissue differential lipogenic capacity in mammalian and avian species. Journal of Lipid Research 42, 106113.
Granlund, L, Larsen, LN, Nebb, HI, Pedersen, JI 2005. Effects of structural changes of fatty acids on lipid accumulation in adipocytes and primary hepatocytes. Biochimica et Biophysica Acta 1687, 2330.
Gregory, PG, Connolly, CK, Toner, M, Sullivan, SJ 2000. In vitro characterization of porcine hepatocyte function. Cell Transplantation 9, 110.
Guillouzo, A 1986. Use of isolated and cultured hepatocytes for xenobiotic metabolism and cytotoxicity studies. In Research in isolated and cultures hepatocytes (ed. A Guillouzo and C Guguen-Guillouzo), pp. 313332. Les Editions INSERM/John Libbey Eurotext Ltd, Paris and London, France and UK.
Hansson, PK, Asztély, A, Clapham, JC, Schreyer, SA 2004. Glucose and fatty acid metabolism in McA-RH7777 hepatoma cells vs. rat primary hepatocytes: responsiveness to nutrient availability. Biochimica et Biophysica Acta 1684, 5462.
Houseknecht, KL, Vanden Heuvel, JP, Moya-Camarena, SY, Portocarrero, CP, Peck, LW, Nickel, KP, Belury, MA 1998. Dietary conjugated linoleic acid normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochemical and Biophysical Research Communications 244, 678682.
José, AAFBV, Gama, MAS, Lanna, DDP 2008. Effects of trans-10, cis-12 conjugated linoleic acid on gene expression and lipid metabolism of adipose tissue of growing pigs. Genetics and Molecular Research 7, 284294.
Koebe, HG, Schildberg, FW 1996. Isolation of porcine hepatocytes from slaughterhouse organs. International Journal of Artificial Organs 19, 5360.
Lee, KC, Azain, MJ, Hausman, DB, Ramsay, TG 2000. Somatotropin and adipose tissue metabolism: substrate and temporal effects. Journal of Animal Science 78, 12361246.
Lepine, AJ, Boyd, RD, Whitehead, DM 1991. Effect of colostrum intake on hepatic gluconeogenesis and fatty acid oxidation in the neonatal pig. Journal of Animal Science 69, 19661974.
Lepine, AJ, Watford, M, Boyd, RD, Ross, DA, Whitehead, DM 1993. Relationship between hepatic fatty acid oxidation and gluconeogenesis in the fasting neonatal pig. British Journal of Nutrition 70, 8191.
Li, Y, Seifert, MF, Ney, DM, Grahn, M, Grant, AL, Allen, KG, Watkins, BA 1999. Dietary conjugated linoleic acids alter serum IGF-1 and IGF binding protein concentrations and reduce bone formation in rats fed (n-6) or (n-3) fatty acids. Journal of Bone and Mineral Research 14, 11531162.
Mantha, L, Palacios, E, Deshaies, Y 1999. Modulation of triglyceride metabolism by glucocorticoids in diet-induced obesity. American Journal of Physiology 277, R455R464.
McGarry, JD, Foster, DW 1980. Effects of exogenous fatty acid concentration on glucagon-induced changes in hepatic fatty acid metabolism. Diabetes 29, 236240.
Nelson, DL, Cox, MM 2000. The citric acid cycle. In Lehninger principles of biochemistry, 3rd edition (ed. DL Nelson and MM Cox), pp. 567597. Worth Publishers, New York, NY, USA.
Nerurkar, LS, Marino, PA, Adams, DO 1981. Quantification of selected intracellular and secreted hydrolases of macrophages. In Manual of macrophage methodology(ed. HB Herscowitz, HT Holden, JA Bellanti and A Ghaffer), pp. 229247. Marcel Dekker Inc., New York, NY, USA.
Nordlie, RC, Sukalski, A, Alvares, FL 1980. Responses of glucose 6-phosphate levels to varied glucose loads in the isolated perfused rat liver. Journal of Biological Chemistry 255, 18341838.
Pariza, MW, Park, Y 2001. The biologically active isomers of conjugated linoleic acid. Progress in Lipid Research 40, 283298.
Pégorier, JP, Duée, PH, Girard, J, Peret, J 1983. Metabolic fate of non-esterified fatty acids in isolated hepatocytes from newborn and young pigs. Evidence for a limited capacity for oxidation and increased capacity for esterification. Biochemical Journal 212, 9397.
Pégorier, JP, Ferré, P, Girard, J 1977. The effects of inhibition of fatty acid oxidation in suckling newborn rats. Biochemical Journal 166, 631634.
Priore, P, Giudetti, AM, Natali, F, Gnoni, GV, Geelen, MJ 2007. Metabolism and short-term metabolic effects of conjugated linoleic acids in rat hepatocytes. Biochimica et Biophysica Acta 1771, 12991307.
Purushotham, A, Shrode, GE, Wendel, AA, Liu, LF, Belury, MA 2007. Conjugated linoleic acid does not reduce body fat but decreases hepatic steatosis in adult Wistar rats. Journal of Nutritional Biochemistry 18, 676684.
Soler-Argilaga, C, Russell, RL, Heimberg, M 1977. Reciprocal relationship between uptake of Ca++ and biosynthesis of glycerolipids from sn-glycerol-3-phosphate by rat liver microsomes. Biochemical and Biophysical Research Communications 78, 10531059.
Sparks, JD, Sparks, CE 1994. Insulin regulation of triacylglycerol-rich lipoprotein synthesis and secretion. Biochimica et Biophysica Acta 1215, 932.
Stangl, GI, Müller, H, Kirchgessner, M 1999. Conjugated linoleic acid effects on circulating hormones, metabolites and lipoproteins, and its proportion in fasting serum and erythrocyte membranes of swine. European Journal of Nutrition 38, 271277.
Svedberg, J, Björntorp, P, Smith, U, Lönnroth, P 1990. Free-fatty acid inhibition of insulin binding, degradation, and action in isolated rat hepatocytes. Diabetes 39, 570574.
Thiel-Cooper, RL, Parrish, JRFC, Sparks, JC, Wiegand, BR, Ewan, RC 2001. Conjugated linoleic acid changes swine performance and carcass composition. Journal of Animal Science 79, 18211828.
Tsuboyama-Kasaoka, N, Takahashi, M, Tanemura, K, Kim, HJ, Tange, T, Okuyama, H, Kasai, M, Ikemoto, S, Ezaki, O 2000. Conjugated linoleic acid supplementation reduces adipose tissue by apoptosis and develops lipodystrophy in mice. Diabetes 49, 15341542.
Williamson, JR, Browning, ET, Scholz, R 1969. Control of mechanisms of gluconeogenesis and ketogenesis. Effects of oleate on gluconeogenesis in perfused rat liver. Journal of Biological Chemistry 244, 46074616.
Witters, LA, Trasko, CS 1979. Regulation of hepatic free fatty acid metabolism by glucagon and insulin. American Journal of Physiology 237, E23E29.
Yamamoto, K, Fukuda, N, Fukui, M, Kai, Y, Ikeda, H, Sakai, T 1996. Increased secretion of triglyceride and cholesterol following inhibition of long-chain fatty acid oxidation in rat liver. Annals of Nutrition and Metabolism 40, 157164.
Youn, JH, Youn, MS, Bergman, RN 1986. Synergism of glucose and fructose in net glycogen synthesis in perfused rat livers. Journal of Biological Chemistry 261, 1596015969.

Keywords

Metabolic regulation of fatty acid esterification and effects of conjugated linoleic acid on glucose homeostasis in pig hepatocytes

  • J. A. Conde-Aguilera (a1), M. Lachica (a1), R. Nieto (a1) and I. Fernández-Fígares (a1)

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