Strukturno podprto načrtovanje, sinteza in vrednotenje reverzibilnih in ireverzibilnih zaviralcev butirilholin esteraze

Meden, Anže (avtor), Gobec, Stanislav (mentor), Knez, Damijan (komentor)

Najpogostejša oblika demence je Alzheimerjeva bolezen, nevrodegenerativna bolezen, za katero so značilni agregati amiloida ß in hiperfosforiliranega proteina tau v centralnem živčnem sistemu, navzven pa se kaže kot progresiven upad kognitivnih funkcij. Pred odobritvijo dveh monoklonskih protiteles v zadnjih dveh letih je bilo na voljo le simptomatsko zdravljenje, kjer so se pretežno uporabljali zaviralci holin esteraz. Človeška butirilholin esteraza (hBChE) je validirana tarča na področju nevrodegenerativnih bolezni, presnove ksenobiotikov, zaščite pred živčnimi bojnimi strupi, homeostaze grelina, itd. V okviru doktorske disertacije smo optimizirali nov strukturni razred selektivnih, reverzibilnih zaviralcev hBChE z indolnim skeletom. Opazili smo, da lahko vzpostavimo dodatno ?–? interakcijo s Trp82 v holin-vezavnem žepku, če na cikloheptilni obroč v strukturi teh zaviralcev pripnemo aromatski obroč. Centralni ?-aminoamidni motiv smo lahko zamenjali s terciarnim aminom in ohranili zaviralno aktivnost. Optimizirane reverzibilne ligande smo lahko pretvorili v psevdoireverzibilne kovalentne zaviralce, ko smo na indolni obroč uvedli karbamatno bojno glavo, karbamoilacijo katalitičnega Ser198 pa smo potrdili z večimi komplementarnimi pristopi. Z optimizacijo steričnih in elektronskih lastnosti karbamatnih N-substituentov smo lahko podaljšali ali skrajšali čas reaktivacije. Nadalje smo z racionalnim načrtovanjem pripravili večtarčne spojine, ki dosežejo tako zaviranje hBChE kot antagonizem na ?2A adrenergičnih receptorjih, pri čemer bi bili takšni ligandi uporabni za zdravljenje, ki spremeni potek Alzheimerjeve bolezni. Natančneje, gre za karbamatna plejotropna predzdravila ?2A antagonista atipamezola, kjer za metabolično aktivacijo poskrbi hBChE, ki postane psevdoireverzibilno zavrta, hkrati pa se sprosti atipamezol, ki se veže na ?2A adrenoreceptorje in ustavi kaskado hiperfosforilacije proteina tau. Na primeru spojine vodnice smo dokazali, da je per os uporabna, prehaja krvno-možgansko pregrado in v mišjem modelu izboljša kognitivne funkcije.

• Jezik: Slovenski jezik
• Ključne besede: butirilholin esteraza, holinesterazni zaviralci, kovalentni zaviralci, karbamati, večtarčne spojine, Alzheimerjeva bolezen
• Vrsta gradiva: Doktorsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2023
• PID: 20.500.12556/RUL-151209
• Datum objave v RUL: 01.10.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Structure-based design, synthesis, and evaluation of reversible and irreversible butyrylcholinesterase inhibitors

Izvleček

The most common variant of dementia is Alzheimer’s disease, a neurodegenerative disease characterized by aggregated amyloid β and hyperphosphorylated tau, which manifests as a progressive deterioration of cognitive functions. Before the approval of two monoclonal antibodies in the last two years, only symptomatic treatment, predominantly based on cholinesterase inhibitors, was available. Human butyrylcholinesterase (hBChE) is a validated drug target in several areas, such as neurodegenerative diseases, detoxification of xenobiotics, nerve agent protection, and ghrelin homeostasis. In this doctoral thesis, we optimized a new structural class of indole-based, selective, reversible hBChE inhibitors. We noticed that an additional π–π interaction with Trp82 in choline-binding pocket could be gained by the introduction of an aromatic ring at the distal end of the cycloheptyl ring of these inhibitors, while the central α-aminoamide moiety could be replaced by a tertiary amine without a loss in inhibitory activity. Taking it one step further, we turned reversible inhibitors into pseudoirreversible covalent ones by introducing a carbamate warhead onto the indole ring. Carbamoylation of catalytic Ser198 was confirmed using different complementary techniques, and through optimization of steric and electronic properties of the carbamate N-substituents, the rate of reactivation could be prolonged or shortened. Furthermore, by rational design, we have prepared multifunctional compounds that achieve both hBChE inhibition and antagonism at α2A adrenoreceptors, and could mean a disease-modifying treatment of Alzheimer's disease. More specifically, these are carbamate pleiotropic prodrugs of a α2A antagonist, atipamezole, that are metabolically activated by hBChE, which is itself inhibited during the process. The liberated atipamezole binds to the α2A adrenoreceptors and blocks the cascade that leads to tau hyperphosphorylation. For one lead compound, we demonstrated its per os availability, blood-brain barrier permeability, and improvement of cognitive functions in a mice model.

• Ključne besede: butyrylcholinesterase, cholinesterase inhibitors, covalent inhibitors, carbamates, multifunctional ligands, Alzheimer's disease