ИСТИНА |
Войти в систему Регистрация |
|
ИСТИНА ИНХС РАН |
||
Influence on the processes of cognition and their improvement is one of the most important problems of modern medicine. The nicotinic acetylcholine receptors (nAChRs) could be considered as potential targets for drugs that improve the cognitive functions of the brain. It has been shown that activation of α7-AChR has a positive effect on cognitive processes such as thinking, concentration, attention, and increases resistance to stress factors. Allosteric modulators of this receptor are regarded as the prototype for biomedical drugs affecting cognition. The human protein Lynx-1 belonging to Ly6/uPAR family could be considered as such drug prototype. This endogenous membrane-tethered neuromodulator is expressed in different areas of the brain and regulates the work of nAChRs. Previously it was shown the involvement of Lynx1 in cognitive processes (memory, learning). Presently Lynx1 is considered as one of the key factors regulating neuronal plasticity. The molecular mechanisms underlying Lynx1 modulatory activity and its effects on cognition remain insufficiently studied. Here we describe the results of electrophysiology study of water-soluble recombinant analogue of human Lynx1 (ws-Lynx1) at the rat brain slices. We used whole-cell patch-clamp configuration and fast drug-application system. It was revealed that ws-Lynx1 at 1 μM concentration didn’t affect the ACh-evoked current in the brain slices, while application of 10 μM ws-Lynx1 resulted in the ~ 30% enhancement of the current amplitude. Using specific inhibitors MLA and DhbE, we showed that α7 and α4β2 nAChRs are responsible for the observed currents, and ws-Lynx1 substantially enhances response at the α7 receptor. The affinity purification of different nAChR subunits from the human cortex extracts using ws-Lynx1 coupled to the magnetic beads was assayed in the presence of different nAChR agonists and antagonists (nicotine, MLA, DhbE, MII, PIA, AUIB). It was shown that MLA and DhbE compete with ws-Lynx1 for the binding to α7 and β4 nAChR subunits, respectively. This indicates that ws-Lynx1 binds to the receptors near the ‘classical’ agonist/antagonist binding site. Obtained results revealed new facets in the Lynx1 action. The work was supported with the Russian Foundation of Basic Researches (project # 16-34-01302) and Russian Science Foundation (project # 16-14-00102).