A prominent functional change during differentiation of lutein cells from follicular thecal and granulosa cells is an enhanced production and secretion of progestins. The regulation of this process is not fully understood but may be associated with the expression of transcription factors which activate genes, products of which are involved in pathways of the cholesterol and lipid metabolism. As peroxisome proliferator-activated receptors (PPARs) play a role in both pathways, we were interested in the expression of PPARgamma, a PPAR form which is involved in adipogenic differentiation. First, we were able to show the expression of PPARgamma in bovine lutein cells (day 12 of the ovarian cycle) at the mRNA and protein level by imaging, flow cytometry and blot analysis, and secondly a role of PPARgamma in the secretion of progesterone. The cells (24 h culture) responded dose dependently by increasing progesterone secretion (up to 1.5-fold of the basal level) to an endogenous ligand of PPARgamma, 15-deoxy-delta12,14 prostaglandin J2 (15-dPGJ2) and to the thiazolidinedione ciglitizone. Aurintricarboxylic acid (ATA) was found to reduce the intracellular PPARgamma level and to promote cell cycle progress, indicating that ATA can be used as a tool for experimental changes of PPARgamma proteins in intact cells and for studying the physiological consequences. The ATA-mediated decrease of PPARgamma was accompanied by reduced progesterone production and a progression of the cell cycle, suggesting a function of PPARgamma in both processes. The response to ATA was abrogated by a high dose (>490 nM) of 15-dPGJ2, suggesting that 15-dPGJ2 exerts its effect on steroidogenic activity via PPARgamma and that the 15-dPGJ2-PPARgamma system plays a role in the maintenance of a differentiated quiescent stage in lutein cells.

This article has been cited by other articles:

				V. Drouineaud, P. Sagot, C. Garrido, E. Logette, V. Deckert, P. Gambert, C. Jimenez, B. Staels, L. Lagrost, and D. Masson Inhibition of progesterone production in human luteinized granulosa cells treated with LXR agonists Mol. Hum. Reprod., June 1, 2007; 13(6): 373 - 379. [Abstract] [Full Text] [PDF]

				N. Tinfo and C. Komar Potential role for peroxisome proliferator-activated receptor {gamma} in regulating luteal lifespan in the rat Reproduction, January 1, 2007; 133(1): 187 - 196. [Abstract] [Full Text] [PDF]

				P Froment, F Gizard, D Defever, B Staels, J Dupont, and P Monget Peroxisome proliferator-activated receptors in reproductive tissues: from gametogenesis to parturition. J. Endocrinol., May 1, 2006; 189(2): 199 - 209. [Abstract] [Full Text] [PDF]

				J. Banerjee and C. M Komar Effects of luteinizing hormone on peroxisome proliferator-activated receptor {gamma} in the rat ovary before and after the gonadotropin surge Reproduction, January 1, 2006; 131(1): 93 - 101. [Abstract] [Full Text] [PDF]

				C. E Minge, N. K. Ryan, K. H. V. D. Hoek, R. L. Robker, and R. J. Norman Troglitazone Regulates Peroxisome Proliferator-Activated Receptors and Inducible Nitric Oxide Synthase in Murine Ovarian Macrophages Biol Reprod, January 1, 2006; 74(1): 153 - 160. [Abstract] [Full Text] [PDF]

				B Lohrke, T Viergutz, and B Kruger Polar phospholipids from bovine endogenously oxidized low density lipoprotein interfere with follicular thecal function J. Mol. Endocrinol., December 1, 2005; 35(3): 531 - 545. [Abstract] [Full Text] [PDF]

				P. Froment, S. Fabre, J. Dupont, C. Pisselet, D. Chesneau, B. Staels, and P. Monget Expression and Functional Role of Peroxisome Proliferator-Activated Receptor-{gamma} in Ovarian Folliculogenesis in the Sheep Biol Reprod, November 1, 2003; 69(5): 1665 - 1674. [Abstract] [Full Text] [PDF]

				C. M. Komar and T. E. Curry Jr Inverse Relationship Between the Expression of Messenger Ribonucleic Acid for Peroxisome Proliferator-Activated Receptor {gamma} and P450 Side Chain Cleavage in the Rat Ovary Biol Reprod, August 1, 2003; 69(2): 549 - 555. [Abstract] [Full Text] [PDF]

				Y. Cui, K. Miyoshi, E. Claudio, U. K. Siebenlist, F. J. Gonzalez, J. Flaws, K.-U. Wagner, and L. Hennighausen Loss of the Peroxisome Proliferation-activated Receptor gamma (PPARgamma ) Does Not Affect Mammary Development and Propensity for Tumor Formation but Leads to Reduced Fertility J. Biol. Chem., May 10, 2002; 277(20): 17830 - 17835. [Abstract] [Full Text] [PDF]

				M. F. M. Mitwally, S. F. Witchel, and R. F. Casper Troglitazone: A Possible Modulator of Ovarian Steroidogenesis Reproductive Sciences, May 1, 2002; 9(3): 163 - 167. [Abstract] [PDF]

				C. M. Komar and T. E. Curry Jr Localization and Expression of Messenger RNAs for the Peroxisome Proliferator-Activated Receptors in Ovarian Tissue from Naturally Cycling and Pseudopregnant Rats Biol Reprod, May 1, 2002; 66(5): 1531 - 1539. [Abstract] [Full Text]

				J. D. Veldhuis, G. Zhang, and J. C. Garmey Troglitazone, an Insulin-Sensitizing Thiazolidinedione, Represses Combined Stimulation by LH and Insulin of de Novo Androgen Biosynthesis by Thecal Cells in Vitro J. Clin. Endocrinol. Metab., March 1, 2002; 87(3): 1129 - 1133. [Abstract] [Full Text] [PDF]

				P. D. Schoppee, J. C. Garmey, and J. D. Veldhuis Putative Activation of the Peroxisome Proliferator-Activated Receptor {gamma} Impairs Androgen and Enhances Progesterone Biosynthesis in Primary Cultures of Porcine Theca Cells Biol Reprod, January 1, 2002; 66(1): 190 - 198. [Abstract] [Full Text]

				C. M. Komar, O. Braissant, W. Wahli, and T. E. Curry Jr. Expression and Localization of PPARs in the Rat Ovary During Follicular Development and the Periovulatory Period Endocrinology, November 1, 2001; 142(11): 4831 - 4838. [Abstract] [Full Text] [PDF]