Određivanje strukture farmakofore, dizajn i in vitro ispitivanje liganada sa višestrukim dejstvom kao potencijalno efikasnijih terapeutika složenih neuroloških i mentalnih oboljenja

Abstract

Disfunkcija serotoninske i dopaminske neurotransmisije u mozgu je u osnovi patofiziologije brojnih neuroloških i mentalnih oboljenja. Definisanje protokola koji integriše in silico i in vitro metode, u cilju prouĉavanja farmakofore multi-potentnih jedinjenja koja deluju na nivou centralnog nervnog sistema (CNS), predstavlja vaţan korak u racionalizaciji procesa otkrivanja novih lekova. Primenom simulacija molekulske dinamike i molekulskog dokinga, kao i analize kvantitativnog odnosa strukture i aktivnosti (eng. 3D-Quantitative Structure Activity Relationship, 3D-QSAR) definisane su kljuĉne strukturne karakteristike dualnih antagonista 5-HT2A i D2 receptora, sa smanjenim afinitetom za H1 receptor. Na osnovu dobijenih rezultata izvršeno je pretraţivanje baza fragmenata primenom metode virtuelnog skrininga (eng. Virtual Screening, VS) u cilju dizajniranja potencijalno bezbednijih i efikasnijih liganada sa višestrukim delovanjem (eng. multi-target), pruţajući smernice za razvoj novih lekova u terapiji sloţenih CNS oboljenja. 3D-QSAR analizom bicikliĉnih α-iminofosfonata definisana je struktura farmakofore selektivnih liganada imidazolinskih I2 receptora, kao potencijalno novih lekova za leĉenje kognitivnih poremećaja. In vitro paralelni test permeabilnosti na veštaĉkim membranama (eng. Parallel Artificial Membrane Permeability Assay, PAMPA) je korišćen za odreĊivanje efektivne permeabilnosti (logPe) kroz krvno-moţdanu barijeru (KMB) jedinjenja koja utiĉu na modulaciju aktivnosti serotoninskog i dopaminskog sistema u mozgu. Dobijeni rezultati su korišćeni u analizi kvantitativnog odnosa strukture i osobina (eng. Quantitative Structure-Property Relationship, QSPR) u cilju razumevanja strukturnih karakteristika koje najviše utiĉu na prolazak jedinjenja kroz KMB. Model formiran primenom metode podrţavajućih vektora (eng. Support-Vector Machine, SVM) i validiran opseţnom statistiĉkom analizom, je korišćen za predviĊanje logPe vrednosti dizajniranih dualnih antagonista i liganada I2 receptora, svrstavajući ih u grupu visoko permeabilnih jedinjenja. Sa ciljem da se dodatno analizira i vizuelizuje proces permeabilnosti centralnodelujućih jedinjenja kroz KMB na molekulskom nivou, korišćene su simulacije usmerene molekulske dinamike (eng. Steered Molecular Dynamics, SMD).

Disturbances in serotoninergic and dopaminergic neurotransmissions in the central nervous system (CNS) play a key role in the pathophysiology of various neurological and mental disorders. Developing an integrative approach through application of in silico and in vitro methods, in order to analyse pharmacophore of multi-target neuroactive compounds, presents a promising strategy in rationalization of drug design process. Molecular dynamics simulations and molecular docking methods in combination with 3D-quantitative structure activity relationship analysis (3D-QSAR) were used to evaluate crucial structural features of potent dual antagonists of 5-HT2A i D2 receptors, with lower antagonistic activity on H1 receptors. The virtual screening of the available fragment libraries was performed with the aim to design novel multi-target compounds with a more effective and safer profile, laying a good foundation for the therapy of complex brain diseases. Moreover, 3D-QSAR analysis of bicyclic α-iminophosphonates was used to reveal the pharmacophore structure of selective imidazoline I2 receptor (I2-IR) ligands, as potentially new drugs for the treatment of cognitive disorders. In vitro parallel artificial membrane permeability assay (PAMPA) was further employed to examine the effective permeability (logPe) through blood brain barrier (BBB) of compounds that affect serotonin and dopamine levels in the CNS. Based on the obtained results, quantitative structure-property relationship (QSPR) analysis was performed with the aim to define structural features that mostly affect the permeability of compounds through BBB. Support- vector machine (SVM) method was used to create predictable and reliable QSPR model that was further employed to predict logPe values of new designed dual antagonists of 5-HT2A/D2 receptors and I2-IR ligands, classifying them into a group of highly permeable compounds. Steered molecular dynamics (SMD) simulations have been carried out to additionally explain and visualize the entire BBB permeation pathway at the molecular level.