Expression of TNF- Receptor Family Members in the Natural Luteal Cycle of the Rhesus Monkey

PELUFFO, MC; YOUNG, KA; STOUFFER, RL

Vancouver, British Columbia

Congreso; 37th SSR Annual Meeting; 2004

SSR (Society for the Study of Reproduction)

Members of the tumor necrosis factor (TNF)-receptor (R) family, including Fas, are transmembrane proteins that mediate various cell processes ranging from proliferation to apoptosis. Since TNF-Rs and their ligands are present in the ovary of many species, we hypothesized that this R-ligand system is involved in the tissue remodeling that occurs during development and regression of the primate corpus luteum (CL). As a first step towards addressing this issue, studies were designed to determine TNF R-ligand mRNA expression and protein localization during the CL lifespan in the menstrual cycle of rhesus monkeys. CL (n=3-4/stage) were collected from anesthetized animals during the early (ECL, d3 post LH surge), mid (MCL, d7), mid-late (MLCL, d10), late (LCL, d14), and very-late (VLCL, d18; menses) luteal phase. Total RNA was extracted from one CL portion for sq RT-PCR analysis, whereas other CL portions were fixed in formalin and used for immunohistochemical analyses, of TNF-alpha and -beta, TNF-RI and -RII, Fas and Fas-ligand (L). Luteal TNF-alpha mRNA levels were 2-to-6 fold greater (p<0.05) at the LCL phase as compared to other stages. TNF-beta mRNA levels were also higher (p<0.05) at the LCL (6- and 2-fold greater than at ECL and MCL, respectively) and declined (2-fold) by the VLCL stage. TNF-RI mRNA levels were higher (p<0.05)) in LCL as compared to ECL, MCL, and MLCL but remained elevated at the VLCL stage. In contrast, TNF-RII, Fas and Fas-L mRNA levels in CL did not change during the luteal phase. Immunostaining for TNF-beta was detected in endothelial, as well as granulosa luteal and theca luteal cells. Specific (compared to preabsorption with antigen) staining was detected in the cytoplasm and, in some cases, in the cell nucleus. Specific immunostaining for TNF-RI, TNF-RII, Fas, and Fas-L was observed in the luteal cells, but not in endothelial cells or surrounding stroma. Moreover, staining for the latter four proteins was more intense in the theca luteal than the granulosa luteal cells. Thus, several members of the TNF R-ligand family are expressed in the primate CL. The highest expression of the TNF-R system in the late luteal phase may signify a role for this cytokine family in death receptor-mediated apoptosis during luteolysis in the menstrual cycle. HD20869, HD18185, RR00163, HD42896, and NICHD Fogarty D43TW00668.