The traditional medical treatment paradigm focuses on prescribing one drug to treat all patients with a specific disease or condition, so called ‘one-size-fits-all’. However, it has been shown... Show moreThe traditional medical treatment paradigm focuses on prescribing one drug to treat all patients with a specific disease or condition, so called ‘one-size-fits-all’. However, it has been shown increasingly that differences between persons, such as in lifestyle or genes, can change both the course of a disease and effect of a drug. In order to adapt medical treatment and drug development to that, a concept know as precision medicine, it is essential to study which and how genetic differences affect drug response. This thesis describes the study of the influences of genetic variation on a specific class of drug targets, the G protein-coupled receptors (GPCRs).Altogether a novel cellular approach towards studying genetic effects on GPCR function has been explored and detailed throughout this thesis. Several GPCRs and different types of genetic variations were investigated, demonstrating together that personal cell lines in combination with label-free technology are an appropriate tool to enable GPCR pharmacogenetic studies. Incorporating aspects such as genetic variation in drug targets, representative model systems and appropriate assay technology are important factors for advancing GPCR drug discovery. The data presented in this thesis contributes towards the progress of applying precision medicine concepts to this class of drug targets. Show less
The Cannabinoid Receptor 2 (CB2R) is a G protein-coupled receptor (GPCR) investigated intensively as therapeutic target, however no drug has reached the market yet. We investigated personal... Show moreThe Cannabinoid Receptor 2 (CB2R) is a G protein-coupled receptor (GPCR) investigated intensively as therapeutic target, however no drug has reached the market yet. We investigated personal differences in CB2R drug responses using a label-free whole-cell assay (xCELLigence) combined with cell lines (Lymphoblastoid Cell Lines) from individuals with varying CB2R genotypes. Responses to agonists, partial agonists and antagonists of various chemical classes were characterized. Endogenous cannabinoids such as 2-AG induced cellular effects vastly different from all synthetic cannabinoids, especially in their time-profile. Secondly, the Q63R polymorphism affected CB2R responses in general. Agonists and especially partial agonists showed higher efficacy in a Q63R minor homozygote versus other genotypes. Non-classical cannabinoid CP55940 showed the most pronounced personal effects with highly reduced potency and efficacy in this genotype. Contrarily, aminoalkylindole compounds showed less individual differences. In conclusion, a label-free whole-cell assay combined with personal cell lines is a promising vehicle to investigate personal differences in drug response originating from genetic variation in GPCRs. Such phenotypic screening allows early identification of compounds prone to personal differences ('precision medicine') or more suited as drugs for the general population. Show less
Getting personal: Endogenous adenosine receptor signaling in lymphoblastoid cell linesJ.M.Hillger, C.Diehl, E.van Spronsen, D.I.Boomsma, P.E.Slagboom, L.H.Heitman, A.P.IJzerman Division of... Show moreGetting personal: Endogenous adenosine receptor signaling in lymphoblastoid cell linesJ.M.Hillger, C.Diehl, E.van Spronsen, D.I.Boomsma, P.E.Slagboom, L.H.Heitman, A.P.IJzerman Division of Medicinal Chemistry, LACDR, Leiden University, The Netherlands Department of Biological Psychology, VU University Amsterdam, The Netherlands Section of Molecular Epidemiology, Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, The Netherlands Abstract Genetic differences between individuals that affect drug action form a challenge in drug therapy. Many drugs target G protein-coupled receptors (GPCRs), and a number of receptor variants have been noted to impact drug efficacy. This, however, has never been addressed in a systematic way, and, hence, we studied real-life genetic variation of receptor function in personalized cell lines. As a showcase we studied adenosine A2A receptor (A2AR) signaling in lymphoblastoid cell lines (LCLs) derived from a family of four from the Netherlands Twin Register (NTR), using a non-invasive label-free cellular assay. The potency of a partial agonist differed significantly for one individual. Genotype comparison revealed differences in two intron SNPs including rs2236624, which has been associated with caffeine-induced sleep disorders. While further validation is needed to confirm genotype-specific effects, this set-up clearly demonstrated that LCLs are a suitable model system to study genetic influences on A2AR response in particular and GPCR responses in general. Graphical abstract Show less
