Androgenic status affects rat preadipocyte adipose conversion from two deep intra-abdominal (epididymal and perirenal) fat depots differently. The aim of this study was to establish whether these site-specific alterations of adipogenesis are related to altered expressions of the transcriptional factors regulating proliferation and differentiation of preadipocytes, c-myc and CCAAT/enhancer binding proteins (C/EBPs: C/EBPalpha and beta). The increased proliferation of epididymal and perirenal preadipocytes from castrated rats was not linked to variations in c-myc mRNA and protein levels. The expression of the early marker of adipogenesis, lipoprotein lipase (LPL), was decreased by androgenic deprivation in epididymal cells but remained insensitive to the androgenic status in perirenal preadipocytes. In contrast, LPL expression increased in subcutaneous preadipocytes from castrated rats, an effect which was partly corrected by testosterone treatment. Expression of C/EBPbeta was unaffected by androgenic status whatever the anatomical origin of the preadipocytes. In contrast, the mRNA and protein levels of C/EBPalpha were greatly decreased by androgenic deprivation in epididymal cells, an alteration which could not be corrected by in vivo testosterone administration. Altogether these results demonstrated that in preadipocytes androgenic deprivation affects site-specifically the expression of LPL, an early marker of adipogenesis and of C/EBPalpha, a master regulator of adipogenesis. These observations contribute to an explanation of why castration induces defective adipose conversion in rat epididymal preadipocytes specifically.

This article has been cited by other articles:

				R. Ray, C. M. Herring, T. A. Markel, P. R. Crisostomo, M. Wang, B. Weil, T. Lahm, and D. R. Meldrum Deleterious effects of endogenous and exogenous testosterone on mesenchymal stem cell VEGF production Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2008; 294(5): R1498 - R1503. [Abstract] [Full Text] [PDF]

				T. Tchkonia, T. Pirtskhalava, T. Thomou, M. J. Cartwright, B. Wise, I. Karagiannides, A. Shpilman, T. L. Lash, J. D. Becherer, and J. L. Kirkland Increased TNF{alpha} and CCAAT/enhancer-binding protein homologous protein with aging predispose preadipocytes to resist adipogenesis Am J Physiol Endocrinol Metab, December 1, 2007; 293(6): E1810 - E1819. [Abstract] [Full Text] [PDF]

				I. Karagiannides, T. Thomou, T. Tchkonia, T. Pirtskhalava, K. E. Kypreos, A. Cartwright, G. Dalagiorgou, T. L. Lash, S. R. Farmer, N. A. Timchenko, et al. Increased CUG Triplet Repeat-binding Protein-1 Predisposes to Impaired Adipogenesis with Aging J. Biol. Chem., August 11, 2006; 281(32): 23025 - 23033. [Abstract] [Full Text] [PDF]

				R. Singh, J. N. Artaza, W. E. Taylor, M. Braga, X. Yuan, N. F. Gonzalez-Cadavid, and S. Bhasin Testosterone Inhibits Adipogenic Differentiation in 3T3-L1 Cells: Nuclear Translocation of Androgen Receptor Complex with {beta}-Catenin and T-Cell Factor 4 May Bypass Canonical Wnt Signaling to Down-Regulate Adipogenic Transcription Factors Endocrinology, January 1, 2006; 147(1): 141 - 154. [Abstract] [Full Text] [PDF]

				A. M. Davidoff, C. Y. C. Ng, J. Zhou, Y. Spence, and A. C. Nathwani Sex significantly influences transduction of murine liver by recombinant adeno-associated viral vectors through an androgen-dependent pathway Blood, July 15, 2003; 102(2): 480 - 488. [Abstract] [Full Text] [PDF]