Biosensors for spatially and temporally resolved measurements of prostanoids

• Applicant: Professor Dr. Moritz Bünemann
• Subject Area: Pharmacy
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 504936713

Prostanoids (prostaglandins and thromboxane) belong to the most important lipid mediators and take part in numerous clinically relevant processes within the entire human body, including the immune and cardiovascular systems. They exert their effect by binding to and activating specific prostanoid receptors, which belong to the G protein-coupled receptor family. The locally formed prostanoids have a short half-life, which leads to an uneven distribution in tissue or organs. Therefore, enabling the measurement of the concentration of specific prostanoids providing spatial and temporal resolution is of particular importance in order to obtain a broader understanding their biological role. However, as no such suitable method exists to date, at the moment prostanoid concentrations are measured by taking mean values of whole tissues or the supernatant of cells. Antibody-based measuring procedures are often used which only provide a snapshot of the concentration of a particular prostanoid without spatial or temporal resolution and sometimes with no distinction between active and inactive metabolites.In an effort to overcome these limitations, our new FRET-based measurement procedure comes into action. The deployment of FRET-based prostanoid receptor conformational sensors is an appropriate means for these measurements. We have succeeded in generating and optimizing a sensor based on the PGE-receptor subtype 4 (EP4 receptor) which seems suitable to act as a biological reporter especially for endogenous PGE2. To evaluate the potential of this approach we measured the real-time release of paracrine PGE2 not only of cell lines but also of primary cells. Moreover using this sensor, we were able to display artificially generated PGE2 gradients with spatial and temporal resolution. In this project, we would like to further develop the presented measuring methods using the example of the EP4 receptor sensor. Furthermore, we will attempt to develop equally comparable biosensors for the remainder of the prostanoid group. A successful implementation of our presented method of FRET-based measurements of the concentration of extracellular GPCR ligands will not only widen the possibility of researching prostanoids, but will also pave the way to discovering the spatial and temporal concentration of further hormones, neurotransmitters and mediators.

• DFG Programme: Research Grants