The sphingolipid receptor S1PR2 is a receptor for Nogo-a repressing synaptic plasticity.

Nogo-A is a membrane protein of the central nervous system (CNS) restricting neurite growth and synaptic plasticity via two extracellular domains: Nogo-66 and Nogo-A-Δ20. Receptors transducing Nogo-A-Δ20 signaling remained elusive so far. Here we identify the G protein-coupled receptor (GPCR) sphingosine 1-phosphate receptor 2 (S1PR2) as a Nogo-A-Δ20-specific receptor.

Characterization of apoptosis induced by photodynamic treatment with hypericin in A431 human epidermoid carcinoma cells.

Hypericin is a naturally occurring metabolite extracted from Hypericum plants and is regarded as a promising photosensitizing agent for applications in the frame of photodynamic treatment (PDT). This treatment procedure is based on the light-induced formation of reactive oxygen species and subsequent destruction of target cells. We used an in vitro model system consisting of human epidermoid carcinoma cells (A431) and hypericin as a photosensitizer to study the time- and dose-dependent characteristics of hypericin-PDT-based induction of cytotoxicity and apoptotic cell death.

Differential effects of glucose deprivation on the cellular sensitivity towards photodynamic treatment-based production of reactive oxygen species and apoptosis-induction.

Photodynamic treatment (PDT) employs a photosensitizer and the light-induced formation of reactive oxygen species--antagonized by cellular antioxidant systems--for the removal of harmful cells. This study addresses the effect of altered carbohydrate metabolism on the cellular antioxidant glutathione system, and the subsequent responses to PDT. It is shown that glucose-deprivation of 18 h prior to PDT causes a reduced level of intracellular glutathione and an increased cytotoxicity of PDT.