PURPOSE To determine whether retinoids are capable of inducing vascular endothelial cell apoptosis and whether the presence of an intact RPE monolayer can block retinoid-induced vascular endothelial cell death. METHODS Confluent fetal bovine aortic endothelial (FBAE) cells were incubated with various concentrations of all-trans or 9-cis retinoic acid (an analogue of 11-cis retinoic acid). Apo...

Retinoic acid modulates proliferation and differentiation of a wide variety of normal and leukemic cells through two distinct families of transcriptional factors: the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). A stereoisomer of retinoic acid, 9-cis-retinoic acid, is a high-affinity ligand for RXR and binds efficiently to RAR. In contrast, all-trans-retinoic acid interac...

The pleiotropic effects of retinoids are mediated by two families of nuclear receptors: RAR (retinoic acid receptors) and RXR (retinoid X receptors). 9-cis-Retinoic acid is a specific ligand for RXR receptors, whereas either 9-cis- or all-trans-retinoic acid activates the RAR receptor family. The existence of RXRs suggests a new role for isomerization in the biology of retinoic acid. We report ...

The retinoids, the natural or synthetic derivatives of Vitamin A (retinol), are essential for the normal development of prostate and have been shown to modulate prostate cancer progression in vivo as well as to modulate growth of several prostate cancer cell lines. 9-cis-retinoic acid and all-trans-retinoic acid are the two most important metabolites of retinol. Gap junctions, formed of protein...

BACKGROUND/AIMS The endogenous retinoid 9-cis-retinoic acid has previously been shown to trigger apoptosis in a wide variety of cells including several tumor cells and has thus been suggested for the treatment of malignancy. Similar to apoptosis of nucleated cells, erythrocytes may enter suicidal erythrocyte death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambli...

Retinoic acid is generated by a two-step mechanism. First, retinol is converted into retinal by a retinol dehydrogenase, and, subsequently, retinoic acid is formed by a retinal dehydrogenase. In vitro, several enzymes are suggested to act in this metabolic pathway. However, little is known regarding their capacity to contribute to retinoic acid biosynthesis in vivo. We have developed a versatil...

Retinoids have been shown to be potent inhibitors of epithelial carcinogenesis. Recent evidence has demonstrated that retinoid actions are mediated through nuclear receptors, which are proteins encoded by the retinoic acid receptor and retinoid X receptor gene families. These receptors are activated by binding to specific retinoids; of the known naturally occurring retinoids, 9-cis retinoic aci...

All-trans and 9-cis retinoic acids function as ligands for retinoic acid receptors (RARs and RXRs), which are ligand-dependent transcription factors and play important roles in development and cellular differentiation. Several retinal dehydrogenases are likely to contribute to the production of all-trans and 9-cis RAs in vivo, but their respective roles in different tissues are still poorly cha...