The Fas-Fas ligand (L) system is one of the major signalling pathways to induce apoptosis in various cells and tissues. The aim of this study was to investigate the expression of the Fas-Fas L system in rat and human oocytes and preimplantation embryos. We determined the expression of Fas and Fas L mRNA of rat oocytes and embryos up to the blastocyst stage, and of human embryos at the 2- or 4-c...

The role of Fas in the regulation of solid tumor growth was investigated. Murine renal carcinoma (Renca) cells were constitutively resistant to Fas-mediated killing in vitro, but exhibited increased expression of Fas and sensitivity to Fas-mediated killing after exposure to IFN-gamma and TNF. Transfected Renca cells overexpressing Fas were efficiently killed in vitro upon exposure to anti-Fas A...

Both the function and regulation of Fas expression in tumours is poorly understood. Our laboratory has reported that cultured, low Fas-expressing tumours undergo massive, yet reversible, up-regulation of cell surface Fas expression when injected into mice. The present study was aimed at determining what causes this enhanced Fas expression and whether the newly expressed Fas functions as a death...

Fas (CD95) mediates apoptosis of many cell types, but the susceptibility of cells to killing by Fas ligand and anti-Fas antibodies is highly variable. Jurkat T cells lacking CD47 (integrin-associated protein) are relatively resistant to Fas-mediated death but are efficiently killed by Fas ligand or anti-Fas IgM (CH11) upon expression of CD47. Lack of CD47 impairs events downstream of Fas activa...

Tissue-specific expression of Fas-ligand (Fas-L) can provide immune privilege by inducing apoptosis of "invading" lymphocytes expressing Fas. However, accelerated diabetes has been reported in transgenic mice expressing Fas-L in islets (RIP-Fas-L) as a result of Fas-dependent fratricide of beta-cells after transfer of diabetogenic clones. Here we studied whether Fas-L could protect islets from ...

Fas/APO-1 is a cell surface protein known to trigger apoptosis in a variety of cell types upon specific antibody binding. Although extensively studied on normal and malignant hematopoietic cells, little is known about Fas/APO-1 on nonhematopoietic cells. In the study presented here, we have examined Fas/APO-1 expression and function on 11 human tumors of nonhematopoietic origin. By flow cytomet...

This study aimed to describe the multivariate structure of Semimembranosus muscle and backfat fatty acid (FA) composition in 798 Italian Large White heavy pigs investigate effects environmental factors carcass characteristics on FA variations. The total variability was characterized by a negative correlation between saturated polyunsaturated FAs, which strongly depended adiposity. Slaughtering ...

This issue's Cell Biology Select highlights recent studies that improve our understanding of how switches and tuners regulate cellular processes. Two studies encompassing very different processes—programmed cell death and plant lateral root formation—both reveal regulatory switches that work independently of enzyme action. Three other studies present new insights into how cell motility, signal ...

A deadly receptor reveals a benevolent side in a study on page 575. Landau and colleagues show that the cell death–inducing receptor Fas is required for protection against neurodegeneration in a mouse model of Parkinson’s disease (PD). The Fas receptor (Fas), best known for its apoptotic role in the immune system, is widely expressed in nonimmune tissues, including the central nervous system. I...

The Fas Ag is a newly defined cell-surface molecule that may mediate apoptosis. The antibody against Fas Ag can induce the apoptotic cell death in cell lines expressing this Ag. PBL subpopulations at various ages were here examined for Fas expression by two-or three-color flow-cytometric analyses using anti-Fas mAb. It was found that Fas Ag was appreciably detected on a proportion of T and B ce...