Expression of Angiotensin II Receptors Type 1 and Type 2 in Human Preadipose Cells During Differentiation

Abstract

Human adipose tissue expresses all the components necessary for the production of angiotensin peptides. Although local effects of angiotensin II on cells from adipose tissue are beginning to be recognised, the expression of angiotensin receptors on human preadipocytes and adipocytes is still controversial. This study addresses the issue by monitoring the mRNA levels as well as the protein production of angiotensin II receptors of type 1 and 2 (AT₁ and AT₂) during differentiation of primary human preadipocytes in culture and in mature adipocytes. mRNA levels of the two receptor types are inversely correlated during adipose conversion. AT₁ receptor mRNA is greatly diminished within 12 days after induction of differentiation, while AT₂ receptor mRNA is elevated. mRNA levels of mature adipocytes confirm this trend. The regulation is not seen as strongly on the protein level. The amount of AT₂ receptor protein is increased, correlating well with the rise in specific glycerol-3-phosphate dehydrogenase activity of the cells, but the AT₁ receptor protein does not vary during the whole differentiation period. As the functional role of AT₂ receptors in adipose tissue is not known to date, further studies have to show if the AT₁-mediated inhibitory actions on adipose conversion are downregulated in differentiating cells through decreased AT₁/AT₂ receptor ratio.

Adipose Tissue - Renin-Angiotensin System - AT₁ - AT₂ - Western Blot - RT-PCR

References

• 1 Schling P, Löffler G. Cross talk between adipose tissue cells: Impact on pathophysiology.  News Physiol. 2002;  17 99-104
• 2 Schling P, Mallow H, Trindl A, Löffler G. Evidence for a local renin angiotensin systemin primary cultured human preadipocytes.  Int J Obes Relat Metab Disord. 1999;  23 336-341
• 3 Crandall D L, Armellino D C, Busler D E, McHendry-Rinde B, Kral J G. Angiotensin II receptors in human preadipocytes: role in cell cycle regulation.  Endocrinology. 1999;  140 154-158
• 4 Schling P, Löffler G. Effects of angiotensin II on adipose conversion and expression of genes of the renin-angiotensin system in human preadipocytes.  Horm Metab Res. 2001;  33 189-195
• 5 Janke J, Engeli S, Gorzelniak K, Luft F C, Sharma A M. Mature adipocytes inhibit in vitro differentiation of human preadipocytes via angiotensin type 1 receptors.  Diabetes. 2002;  51 1699-1707
• 6 Darimont C, Vassaux G, Ailhaud G, Negrel R. Differentiation of preadipose cells: paracrine role of prostacyclin upon stimulation of adipose cells by angiotensin-II.  Endocrinology. 1994;  135 2030-2036
• 7 Burson J M, Aguilera G, Gross K W, Sigmund C D. Differential expression of angiotensin receptor 1A and 1B in mouse.  Am J Physiol. 1994;  267 E260-E267
• 8 Jones B H, Standridge M K, Moustaid N. Angiotensin II increases lipogenesis in 3T3-L1 and human adipose cells.  Endocrinology. 1997;  138 1512-1519
• 9 Mallow H, Trindl A, Löffler G. Production of angiotensin II receptors type one (AT₁) and type two (AT₂) during the differentiation of 3T3-L1 preadipocytes.  Horm Metab Res. 2000;  32 500-503
• 10 Crandall D L, Herzlinger H E, Saunders B D, Armellino D C, Kral J G. Distribution of angiotensin II receptors in rat and human adipocytes.  J Lipid Res. 1994;  35 1378-1385
• 11 Cassis L A, Fettinger M J, Roe A L, Shenoy U R, Howard G. Characterization and regulation of angiotensin II receptors in rat adipose tissue - Angiotensin receptors in adipose tissue.  Adv Exp Med Biol. 1996;  396 39-47
• 12 Pinterova L, Krizanova O, Zorad S. Rat epididymal fat tissue express all components of the renin-angiotensin system.  Gen Physiol Biophys. 2000;  19 329-334
• 13 Engeli S, Gorzelniak K, Kreutz R, Runkel N, Distler A, Sharma A M. Co-expression of renin-angiotensin system genes in human adipose tissue.  J Hypertens. 1999;  17 555-560
• 14 Skurk T, Röhrig K, Hauner H. Angiotensin II stimuliert die Lipolyse in primär kultivierten humanen Adipozyten (abstract).  Aktuel Ernaehr Med. 2000;  25 248
• 15 Horiuchi M, Hamai M, Cui T-X, Iwai M, Minokoshi Y. Cross talk between angiotensin II type 1 and type 2 receptors: cellular mechanism of angiotensin type 2 receptor-mediated cell growth inhibition.  Hypertens Res. 1999;  22 67-74
• 16 Shillabeer G, Forden J M, Lau D CW. Induction of preadipocyte differentiation by mature fat cells in the rat.  J Clin Invest. 1989;  84 381-387
• 17 Ailhaud G. Cross talk between adipocytes and their precursors: Relationships with adipose tissue development and blood pressure.  Ann NY Acad Sci. 1999;  892 127-133
• 18 Pairault J, Green H. A study of the adipose conversion of suspended 3T3 cells by using glycerophosphate dehydrogenase as differentiation marker.  Proc Natl Acad Sci USA. 1979;  76 5138-5142
• 19 Bradford M M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilising the principle of protein-dye binding.  Anal Biochem. 1976;  72 248-254
• 20 Laemmli U K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4.  Nature. 1970;  227 680-685
• 21 Gorzelniak K, Engeli S, Janke J, Luft F C, Sharma A M. Hormonal regulation of the human adipose-tissue renin-angiotensin system: relationship to obesity and hypertension.  J Hypertens. 2002;  20 965-973
• 22 Garcia-Sainz J A, Martinez-Alfaro M, Romero-Avila M T, Gonzalez-Espinosa C. Characterisation of the AT₁ angiotensin II receptor expressed in guinea pig liver.  J Endocrinol. 1997;  154 133-138
• 23 Harrison-Bernard L M, Navar L G, Ho M M, Vinson G P, El-Dahr S S. Immunohistochemical localisation of Ang II AT₁ receptor in adult rat kidney using a monoclonal antibody.  Am J Physiol. 1997;  273 F170-F177
• 24 Nielsen A H, Schauser K, Winther H, Dantzer V, Poulsen K. Angiotensin II receptors and renin in the porcine uterus: myometrial AT₂ and endometrial AT₁ receptors are down-regulated during gestation.  Clin Exp Pharmacol Physiol. 1997;  24 309-314
• 25 Gáborik Z, Szaszák M, Szidonya L, Balla B, Paku S, Catt K J, Clark A JL, Hunyady L. Beta-arrestin- and dynamin-dependent endocytosis of the AT₁ angiotensin receptor.  Mol Pharmacol. 2001;  59 239-247
• 26 Chen R, Mukhin Y V, Garnovskaya M N, Thielen T E, Iijima Y, Huang C, Raymond J R, Ullian M E, Paul R V. A functional angiotensin II receptor-GFP fusion protein: evidence for agonist-dependent nuclear translocation.  Am J Physiol. 2000;  279 F440-448
• 27 Mori Y, Matsubara H, Murasawa S, Kijima K, Murayama K, Tsukaguchi H, Okubo N, Hamakubo T, Inagami T, Iwasaka T, Inada M. Translational Regulation of Angiotensin II Type 1A Receptor.  Hypertension. 1996;  28 810-817
• 28 Giacchetti G, Sechi L A, Griffin C A, Don B R, Mantero F, Schambelan M. The tissue renin-angiotensin system in rats with fructose-induced hypertension: overexpression of type 1 angiotensin II receptor in adipose tissue.  J Hypertens. 2000;  18 695-702
• 29 Cassis L A, Dwoskin L P. Presynaptic modulation of neurotransmitter release by endogeneous angiotensin II in brown adipose tissue.  J Neural Transm. 1991;  34 129-137
• 30 Boschmann M, Ringel J, Klaus S, Sharma A M. Metabolic and hemodynamic response of adipose tissue to angiotensin II.  Obes Res. 2001;  9 486-491
• 31 Phillips M I, Speakman E A, Kimura B. Levels of angiotensin and molecular biology of the tissue renin angiotensin systems.  Regul Pept. 1993;  43 1-20
• 32 Nishiyama A, Seth D M, Navar L G. Renal interstitial fluid concentrations of angiotensins I and II in anesthetized rats.  Hypertension. 2002;  39 129-134
• 33 Frederich R CJ, Kahn B B, Peach M J, Flier J S. Tissue-specific nutritional regulation of angiotensinogen in adipose tissue.  Hypertension. 1992;  19 339-344
• 34 Gabriely I, Yang X M, Cases J A, Ma X H, Rossetti L, Barzilai N. Hyperglycemia modulates angiotensinogen gene expression.  Am J Physiol. 2001;  281 R795-R802
• 35 Aubert J, Safonova I, Negrel R, Ailhaud G. Insulin down-regulates angiotensinogen gene expression and angiotensinogen secretion in cultured adipose cells.  Biochem Biophys Res Commun. 1998;  250 77-82
• 36 Safonova I, Aubert J, Negrel R, Ailhaud G. Regulation by fatty acids of angiotensinogen gene expression in preadipose cells.  Biochem J. 1997;  322 235-239
• 37 Aubert J, Darimont C, Safonova I, Ailhaud G, Negrel R. Regulation by glucocorticoids of angiotensinogen gene expression and secretion in adipose cells.  Biochem J. 1997;  328 701-706
• 38 McCallum F S, Maden B E. Human 18 S ribosomal sequence inferred from DNA sequence. Variations in 18 S sequence and secondary modification patterns between vertebrates.  Biochem J. 1985;  232 725-733
• 39 Takayanagi R, Ohnaka K, Sakai Y, Nakao R, Yanase T, Haji M, Inagami T, Furuta H, Gou D F, Nakamuta M, Nawata H. Molecular cloning, sequence analysis, and expression of cDNA encoding human type-1 angiotensin II receptor.  Biochem Biopyhs Res Commun. 1992;  183 910-916
• 40 Takayanagi R, Ohnaka K, Sakai Y, Ikuyama S, Nawata H. Molecular cloning and characterisation of the promoter for human type-1 angiotensin receptor gene.  Biochem Biophys Res Commun. 1994;  200 1264-1270
• 41 Martin M M, Su B, Elton T S. Molecular cloning of the human angiotensin II type 2 receptor cDNA.  Biochem Biophys Res Commun. 1994;  205 645-651
• 42 Martin M M, Su B, Elton T S. Molecular cloning of the human AT₂ receptor.  Adv Exp Med Biol. 1996;  396 153-165