There is a growing interest in peroxisome proliferator-activated receptors (PPARs) as major players in the regulation of lipid and carbohydrate metabolism. Drugs targeting PPARs were in fact shown to have major relevance for the treatment of diseases associated with aging, such as arteriosclerosis and diabetes. However, a variety of toxic effects associated with PPAR ligand administration has been documented, including hepatocarcinogenesis, which may severely limit its therapeutic use. A better comprehension of the multiplicity of PPAR physiological functions is therefore mandatory for the development of novel, safer drugs. We here describe the generation of a novel transgenic mouse for the detection of the generalized activities of PPARs, the PPAR responsive element-Luc reporter mouse. In this model luciferase expression is under the control of a PPAR-inducible promoter in all target organs. By optical imaging and ex vivo analysis, we were able to demonstrate the remarkable gender specificity of the PPAR transcriptional activity in liver. In fact, in the liver of female PPAR responsive element-Luc, the PPAR reporter transgene is more than one order of magnitude less expressed, thus leading to the conclusion that the signaling in females is much less activated than in males. Diet or hormonal manipulations as demonstrated here by treatments with high-fat diet or gonad removal and hormone replacement do not influence this low activation. The extent of the gender difference in PPAR transcriptional activity and the ineffectiveness of hormone treatments or diet to significantly elevate liver PPAR activity in females led us to hypothesize that gender-specific epigenetic events occurring during development may affect PPAR signaling in the liver. This study sets the ground for understanding the differential susceptibility of the two genders to metabolic disorders; furthermore, the model generated provides a novel opportunity for the molecular characterization of PPAR activity in pathophysiological conditions.

A beneficial effect of the addition of LC to RBCs stored at 4 degrees C was evident. This effect may be related to both biophysical and metabolic actions on the cell membrane.

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We report here the finding of a new pharmacological activity of a well known antagonist of peroxisome proliferator-activated receptors (PPARs). PPARs belong to the family of nuclear receptors playing a relevant role in mammalian physiology and are currently believed to represent a major target for the development of innovative drugs for metabolic and inflammatory diseases. In the present study, the application of reporter animal technology was instrumental to obtain the global pharmacological profiling indispensable to unraveling 3-(1-(4-chlorobenzyl)-3-t-butylthio-5-isopropylindol-2-yl)-2,2-dimethylpropanoic acid (MK-886)-selective PPAR modulator (SPPARM) activity not underlined by previous traditional, cell-based studies. The results of this study, demonstrating the usefulness of reporter mice, may open new avenues for the development of innovative drugs for cardiovascular, endocrine, neural, and skeletal systems characterized by limited side effects.

Phenol ethers Q 0270 Synthesis and Biological Evaluation of New Clofibrate Analogues as Potential PPARα Agonists. -None of the novel analogues show PPAR activity. -(PERRONE, M. G.; SANTANDREA, E.; DELL'UOMO, N.; GIANNESSI, F.; MILAZZO, F. M.; SCIARRONI, A. F.; SCILIMATI*, A.; TORTORELLA, V.; Eur. J. Med. Chem. 40 (2005) 2, 143-154; Dip. Farmacochim., Univ. Bari, I-70125 Bari, Italy; Eng.) -K. Schneider 25-074