Kinetic profiling and functional characterization of 8-phenylxanthine derivatives as A adenosine receptor antagonists.

A adenosine receptor (AAR) antagonists have therapeutic potential in inflammation-related diseases such as asthma, chronic obstructive pulmonary disease and cancer. However, no drug is currently clinically approved, creating a demand for research on novel antagonists. Over the last decade, the study of target binding kinetics, along with affinity and potency, has been proven valuable in early drug discovery stages, as it is associated with improved in vivo drug efficacy and safety.

Targeting the K11.1 (hERG) channel with allosteric modulators. Synthesis and biological evaluation of three novel series of LUF7346 derivatives.

We synthesized and evaluated three novel series of substituted benzophenones for their allosteric modulation of the human K11.1 (hERG) channel. We compared their effects with reference compound LUF7346 previously shown to shorten the action potential of cardiomyocytes derived from human stem cells.

Design and pharmacological profile of a novel covalent partial agonist for the adenosine A receptor.

Partial agonists for G protein-coupled receptors (GPCRs) provide opportunities for novel pharmacotherapies with enhanced on-target safety compared to full agonists. For the human adenosine A receptor (hAAR) this has led to the discovery of capadenoson, which has been in phase IIa clinical trials for heart failure. Accordingly, the design and profiling of novel hAAR partial agonists has become an important research focus.

Constitutive activity of the metabotropic glutamate receptor 2 explored with a whole-cell label-free biosensor.

Label-free cellular assays using a biosensor provide new opportunities for studying G protein-coupled receptor (GPCR) signaling. As opposed to conventional in vitro assays, integrated receptor-mediated cellular responses are determined in real-time rather than a single downstream signaling pathway. In this study, we examined the potential of a label-free whole cell impedance-based biosensor system (i.

Label-free technology and patient cells: from early drug development to precision medicine.

Drug development requires physiologically more appropriate model systems and assays to increase understanding of drug action and pathological processes in individual humans. Specifically, patient-derived cells offer great opportunities as representative cellular model systems. Moreover, with novel label-free cellular assays, it is often possible to investigate complex biological processes in their native environment.

Small molecule absorption by PDMS in the context of drug response bioassays.

The polymer polydimethylsiloxane (PDMS) is widely used to build microfluidic devices compatible with cell culture. Whilst convenient in manufacture, PDMS has the disadvantage that it can absorb small molecules such as drugs. In microfluidic devices like "Organs-on-Chip", designed to examine cell behavior and test the effects of drugs, this might impact drug bioavailability.

Getting personal: Endogenous adenosine receptor signaling in lymphoblastoid cell lines.

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.

Equilibrium and kinetic selectivity profiling on the human adenosine receptors.

Classical evaluation of target selectivity is usually undertaken by measuring the binding affinity of lead compounds against a number of potential targets under equilibrium conditions, without considering the kinetics of the ligand-receptor interaction. In the present study we propose a combined strategy including both equilibrium- and kinetics-based selectivity profiling. The adenosine receptor (AR) was chosen as a prototypical drug target.

Human G protein-coupled receptor studies in Saccharomyces cerevisiae.

G protein-coupled receptors (GPCRs) are one of the largest families of membrane proteins, with approximately 800 different GPCRs in the human genome. Signaling via GPCRs regulates many biological processes, such as cell proliferation, differentiation, and development. In addition, many receptors have a pivotal role in immunophysiology.

Persistent GnRH receptor activation in pituitary αT3-1 cells analyzed with a label-free technology.

The gonadotropin-releasing hormone (GnRH) receptor is a drug target for certain hormone-dependent diseases such as prostate cancer. In this study, we examined the activation profiles of the endogenous ligand, GnRH and a well-known marketed analog, buserelin using a label-free assay in pituitary αT3-1 cells with endogenous GnRH receptor expression. This whole cell impedance-based technology allows for the real-time measurement of morphological cellular changes.

The role of the C-terminus of the human hydroxycarboxylic acid receptors 2 and 3 in G protein activation using Gα-engineered yeast cells.

In the present study we focused our attention on the family of hydroxycarboxylic acid (HCA) receptors, a GPCR family of three members, of which the HCA2 and HCA3 receptors share 95% high sequence identity but differ considerably in C-terminus length with HCA3 having the longest tail. The two receptors were expressed and analysed for their activation profile in Saccharomyces cerevisiae MMY yeast strains that have different G protein Gα subunits. The hHCA2 receptor was promiscuous in its G protein coupling preference.

Synthesis and biological evaluation of negative allosteric modulators of the Kv11.1(hERG) channel.

We synthesized and evaluated a series of compounds for their allosteric modulation at the Kv11.1 (hERG) channel. Most compounds were negative allosteric modulators of [(3)H]dofetilide binding to the channel, in particular 7f, 7h-j and 7p.

Scanning mutagenesis in a yeast system delineates the role of the NPxxY(x)(5,6)F motif and helix 8 of the adenosine A(2B) receptor in G protein coupling.

The adenosine receptor subfamily includes four subtypes: the A1, A2A, A2B and A3 receptors, which all belong to the superfamily of G protein-coupled receptors (GPCRs). The adenosine A2B receptor is the least investigated of the adenosine receptors, and the molecular mechanisms of its activation have hardly been explored. We used a single-GPCR-one-G protein yeast screening method in combination with mutagenesis studies, molecular modeling and bio-informatics to investigate the importance of the different amino acid residues of the NPxxY(x)6F motif and helix 8 in the human adenosine A2B receptor (hA2BR) activation.

Affinity and kinetics study of anthranilic acids as HCA2 receptor agonists.

Structure-affinity relationship (SAR) and structure-kinetics relationship (SKR) studies were combined to investigate a series of biphenyl anthranilic acid agonists for the HCA2 receptor. In total, 27 compounds were synthesized and twelve of them showed higher affinity than nicotinic acid. Two compounds, 6g (IC50=75nM) and 6z (IC50=108nM) showed a longer residence time profile compared to nicotinic acid, exemplified by their kinetic rate index (KRI) values of 1.

When structure-affinity relationships meet structure-kinetics relationships: 3-((Inden-1-yl)amino)-1-isopropyl-cyclopentane-1-carboxamides as CCR2 antagonists.

Chemokine ligand 2 (CCL2) mediates chemotaxis of monocytes to inflammatory sites via interaction with its G protein-coupled receptor CCR2. Preclinical animal models suggest that the CCL2-CCR2 axis has a critical role in the development and maintenance of inflammatory disease states (e.g.

Bias in chemokine receptor signalling.

Chemokine receptors are widely expressed on a variety of immune cells and play a crucial role in normal physiology as well as in inflammatory and infectious diseases. The existence of 23 chemokine receptors and 48 chemokine ligands guarantees a tight control and fine-tuning of the immune system. Here, we discuss the multiple regulatory mechanisms of chemokine signalling at a systemic, cellular, and molecular level.

Allosteric modulators of the hERG K(+) channel: radioligand binding assays reveal allosteric characteristics of dofetilide analogs.

Drugs that block the cardiac K(+) channel encoded by the human ether-à-go-go gene (hERG) have been associated with QT interval prolongation leading to proarrhythmia, and in some cases, sudden cardiac death. Because of special structural features of the hERG K(+) channel, it has become a promiscuous target that interacts with pharmaceuticals of widely varying chemical structures and a reason for concern in the pharmaceutical industry. The structural diversity suggests that multiple binding sites are available on the channel with possible allosteric interactions between them.