GPR18, still considered an orphan receptor, may respond to endocannabinoids, whose canonical receptors are CB and CB. GPR18 and CB receptors share a role in peripheral immune response regulation and are co-expressed in microglia, which are immunocompetent cells in the central nervous system (CNS). We aimed at identifying heteroreceptor complexes formed by GPR18 and CBR or CBR in resting and activated microglia. Receptor-receptor interaction was assessed using energy-transfer approaches, and receptor function by determining cAMP levels and ERK1/2 phosphorylation in heterologous cells and primary cultures of microglia. Heteroreceptor identification in primary cultures of microglia was achieved by in situ proximity ligation assays. Energy transfer results showed interaction of GPR18 with CBR but not with CBR. CB-GPR18 heteroreceptor complexes displayed particular functional properties (heteromer prints) often consisting of negative cross-talk (activation of one receptor reduces signaling arising from the partner receptor) and cross-antagonism (the response of one of the receptors is blocked by a selective antagonist of the partner receptor). Activated microglia showed the heteromer print (negative cross-talk and bidirectional cross-antagonism) and increased expression of CBR and GPR18. Due to the important role of CBR in neuroprotection, we further investigated heteroreceptor occurrence in primary cultures of microglia from transgenic mice overexpressing human APP, an Alzheimer's disease model. Microglial cells from transgenic mice showed the heteromer print and functional interactions that were similar to those found in cells from wild-type animals that were activated by treatment with lipopolysaccharide and interferon-γ. Our results suggest that GPR18 and its heteromers may play important roles in neurodegenerative processes.
Cyclin-dependent kinases (CDKs) are involved in many crucial processes, such as cell cycle and transcription, as well as communication, metabolism, and apoptosis. The kinases are organized in a pathway to ensure that, during cell division, each cell accurately replicates its DNA, and ensure its segregation equally between the two daughter cells. Deregulation of any of the stages of the cell cycle or transcription leads to apoptosis but, if uncorrected, can result in a series of diseases, such as cancer, neurodegenerative diseases (Alzheimer’s or Parkinson’s disease), and stroke. This review presents the current state of knowledge about the characteristics of cyclin-dependent kinases as potential pharmacological targets.
A b s t r a c tBovine tuberculosis is an infectious disease that occurs in many species of both domestic and wild animals, as well as those held in capti vity. The etiological factor is the acid resistant bacillus (Mycobacterium bovis or Mycobacterium caprae), which is characterized by the major pathogenicity among mycobacteria belonging to the Mycobacterium tuberculosis complex. The material from 8 antelopes from the zoo, suspected for tuberculosis were examined, and M. bovis strains were isolated from 6 of them. The spoligotyping method showing spoligo pattern 676763777777600. In Poland, this spoligotype has not been observed so far.K e y w o r d s: Mycobacterium bovis, antelopes, MTBC, public health, zoo
Available data support the proposition that the examined compounds with adenosine A receptor affinity may be an interesting target for the development of antidepressant and/or anxiolytic agents.
A library of 27 novel amide derivatives of annelated xanthines was designed and synthesized. The new compounds represent 1,3-dipropyl- and 1,3-dibutyl-pyrimido[2,1-]purinedione-9-ethylphenoxy derivatives including a CHCONH linker between the (CH)-amino group and the phenoxy moiety. A synthetic strategy to obtain the final products was developed involving solvent-free microwave irradiation. The new compounds were evaluated for their adenosine receptor (AR) affinities. The most potent derivatives contained a terminal tertiary amino function. Compounds with nanomolar AR affinities and at the same time high water-solubility were obtained (A ( = 24-605 nM), A ( = 242-1250 nM), A ( = 66-911 nM) and A ( = 155-1000 nM)). 2-(4-(2-(1,3-Dibutyl-2,4-dioxo-1,2,3,4,7,8-hexahydropyrimido[2,1-]purin-9(6)-yl)ethyl)phenoxy)--(3-(diethylamino)propyl)acetamide () and the corresponding -(2-(pyrrolidin-1-yl)ethyl)acetamide () were found to be the most potent antagonists of the present series. While showed CYP inhibition and moderate metabolic stability, was found to possess suitable properties for applications. In an attempt to explain the affinity data for the synthesized compounds, molecular modeling and docking studies were performed using homology models of A and A adenosine receptors. The potent compound was used as an example for discussion of the possible ligand-protein interactions. Moreover, the compounds showed high water-solubility indicating that the approach of introducing a basic side chain was successful for the class of generally poorly soluble AR antagonists.
Annelated purinedione derivatives have been shown to act as possible multiple‐target ligands, addressing adenosine receptors and monoaminooxidases. In this study, based on our previous results, novel annelated pyrimido‐ and diazepino[2,1‐f]purinedione derivatives were designed as dual‐target‐directed ligands combining A2A adenosine receptor (AR) antagonistic activity with blocking monoamine oxidase B. A library of 19 novel compounds was synthesized and biologically evaluated in radioligand binding studies at AR subtypes and for their ability to inhibit MAO‐B. This allowed 9‐(2‐chloro‐6‐fluorobenzyl)‐3‐ethyl‐1‐methyl‐6,7,8,9‐tetrahydropyrimido[2,1‐f]purine‐2,4(1H,3H)‐dione (13 e; Ki human A2AAR: 264 nM and IC50 human MAO‐B: 243 nM) to be identified as the most potent dual‐acting ligand from this series. ADMET parameters were estimated in vitro, and analysis of the structure‐activity relationships was complemented by molecular‐docking studies based on previously published X‐ray structures of the protein targets. Such dual‐acting ligands, by selectively blocking A2A AR, accompanied by the inhibition of dopamine metabolizing enzyme MAO‐B, might provide symptomatic and neuroprotective effects in, among others, the treatment of Parkinson disease
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