Fas ligand, Fas antigen and Bcl-2 expression in human endometrium during the menstrual cycle

Abstract

In this study, we investigate Fas ligand expression in the human endometrium during the menstrual cycle in relation to Fas antigen and Bcl-2 expression, using immunoelectron microscopy and Western blotting. Endometrial samples were obtained from 54 pre-menopausal non-pregnant women who underwent laparotomies for benign diseases. The Fas ligand, as well as the Fas antigen, were expressed on the surface of endometrial glandular cells throughout the menstrual cycle, whereas Bcl-2 showed a cyclic expression pattern, peaking during the late proliferative phase. A noteworthy finding was that both the Fas ligand and the Fas antigen were localized on Golgi apparatuses and vesicles, in addition to the cell membranes, during the late proliferative phase. These results indicate that the Fas ligand and Fas antigen which are localized on Golgi apparatus and vesicles during the late proliferative phase are incorporated into the cell membranes during the secretory phase, and are co-expressed on the cell membranes of endometrial glands throughout the menstrual cycle. The factors regulating Fas-mediated apoptosis in the human endometrium, including the level of expression of the Fas ligand and Bcl-2 are discussed.

Interferon-γ Induces Fas Trafficking and Sensitization to Apoptosis in Vascular Smooth Muscle Cells via a PI3K- and Akt-Dependent Mechanism

“…The majority of Fas in VSMCs is stored in the Golgi apparatus, and cells are refractive to Fas-induced death without presensitization. This phenomenon is observed in a variety of normal and diseased cell types, including melanoma, lymphoma, 33 prostatic 34 or breast carcinoma, or normal liver, 35 endometrium, 36 and endothelial cells, 37 and may have evolved as a mechanism for immune evasion. Fas-induced apoptosis may be regulated in VSMCs by a variety of cytokines, many of which are present in the atherosclerotic plaque.…”

Preclinical Antitumor Efficacy of BAY 1129980—a Novel Auristatin-Based Anti-C4.4A (LYPD3) Antibody–Drug Conjugate for the Treatment of Non–Small Cell Lung Cancer

“…Stained IHC samples were evaluated by a trained pathologist (Provitro GmbH or Ventana). The percentage of tumor cells staining positive for C4.4A at each intensity level (0, 1, 2, or 3) was calculated and an H-score was calculated as described previously (23). An intensity score was also calculated for each sample representing the highest intensity (on a scale of 0 to 3þ) with staining at that level or higher in at least 30% of tumor cells (membrane staining only).…”

DFF45 Expression in Human Endometrium Is Associated with Menstrual Cycle Phases and Decreases after Menopause

“…Apoptosis in human endometrium may be triggered by activation of both receptor apoptotic factors [Fas protein, Fas ligand (FasL), tumor necrosis factor-alpha (TNFα)] and mitochondrial factors (bcl-2 antiapoptotic protein, bax-proapoptotic protein, bid protein, cytochrome c) [3]. Expression of Fas and FasL was confirmed in human endometrium throughout the menstrual cycle, and their stronger immunoreactivity in the secretory endometrium suggests that Fas-FasL interactions may initiate the receptor apoptosis pathway during the second phase of the menstrual cycle [4]. An increased TNFα level was also detected in human glandular and colloid arterial endothelium during the secretory phase compared to proliferative phase of the menstrual cycle [5].…”