Primerjava mišjih modelov s kognitivnim upadom in ocena terapevtskega potenciala nove spojine, ki zavira delovanje butirilholinesteraze

Žnidaršič, Neža (avtor), Snoj, Tomaž (mentor), Grgurevič, Neža (komentor)

Demenca, zlasti Alzheimerjeva bolezen (AB), še vedno predstavlja velik klinični izziv, saj prizadene milijone ljudi po vsem svetu in močno vpliva na kakovost življenja bolnikov ter njihovih svojcev. Napredek pri razvoju učinkovitih strategij za zdravljenje in razumevanje bolezni poteka počasi, kar je deloma tudi posledica pomanjkanja ustreznih živalskih modelov za preučevanje njenih kompleksnih mehanizmov. Da bi bolje razumeli potek bolezni in proučili možnosti terapevtskih pristopov, smo preučevali dva mišja modela s potencialno izraženim kognitivnim upadom. Samce in ovariektomirane samice miši C57BL/6, ki so v odmerku 30 mg/kg prejeli aftin-4, spojino, ki sproži tvorbo amiloida, smo primerjali z mišmi iste linije, starimi 15–16 mesecev. Izvedli smo teste obnašanja in določili plazemske ravni amiloida ß (Aß1–40 in Aß1–42), označevalcev oksidativnega stresa (glutation peroksidaze, superoksid dismutaze in malondialdehida (MDA)) ter ugotavljali reaktivnost astrocitov glede na raven glialnega fibrilarnega kislega proteina (GFAP). Rezultati niso pokazali značilnih razlik v obnašanju pri miših, ki so prejele aftin-4, starih in kontrolnih miših. Pri miših, ki so prejele aftin-4, smo zaznali nižje ravni MDA v možganih in višje koncentracije Aß1–42 v plazmi. Razmerje Aß1–42/Aß1–40 je bilo primerljivo med vsemi skupinami. Kvalitativna analiza izražanja GFAP z metodo western blot je pokazala intenzivnejše pasove pri starih miših in miših, ki so prejele aftin-4, kar kaže na povečano aktivacijo astrocitov. Učinki aftina-4 in starosti niso bili odvisni od spola, saj nismo zaznali statistično značilne interakcije med spolom in eksperimentalno skupino. Rezultati kažejo, da se pri farmakološkem modelu z aftinom-4 in pri modelu starih miši ni pojavil merljiv kognitivni upad. V nadaljevanju smo raziskali terapevtski potencial večtarčne spojine, zasnovane za zaviranje delovanja butirilholinesteraze (BChE) in antagonizem adrenergičnih receptorjev ?2A. Spojina vodnica, MSG-44, je pleiotropno karbamatno predzdravilo, ki se aktivira ob stiku z BChE v plazmi, kar vodi do psevdo-ireverzibilne inhibicije encima in sproščanja atipamezola. Sproščeni atipamezol se veže na adrenergične receptorje ?2A in prekine kaskado hiperfosforilacije proteina tau. Naša študija je pokazala, da je spojina MSG-44 primerna za peroralno uporabo in prehaja krvno-možgansko pregrado. Spojina pri modelu starih mišjih samcev ni imela vpliva na kognitivne funkcije. Raziskava poudarja pomen raziskovanja novih terapevtskih strategij za AB in kompleksnost razvoja zanesljivih živalskih modelov.

• Jezik: Slovenski jezik
• Ključne besede: miši, živalski modeli, obnašanje živali, kognitivni upad, demenca, Alzheimerjeva bolezen, amiloid, aftin-4, oksidativni stres, butirilholinesteraza, atipamezol, adrenergični receptorji
• Vrsta gradiva: Doktorsko delo/naloga
• Organizacija: VF - Veterinarska fakulteta
• Leto izida: 2025
• PID: 20.500.12556/RUL-174291
• Datum objave v RUL: 01.10.2025

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Comparison of mouse models with cognitive impairment and evaluation of the therapeutic potential of a new compound that inhibits the action of butyrylcholinesterase

Izvleček

Dementia, particularly Alzheimer’s disease (AD), remains a major clinical challenge. It affects millions of people around the world and has a profound impact on the quality of life of patients and their families. Progress in developing effective strategies to treat and understand the disease has been slow, partly due to the lack of suitable animal models to study its complex mechanisms. To change this, we studied two models to better understand the disease and evaluate potential therapeutic approaches. We compared male and ovariectomized female C57BL/6 mice treated with 30 mg/kg aftin-4 - a compound that could induce amyloid-like toxicity - with naturally aged (15 - 16 months old) mice. Behavioral assessments were performed along with postmortem analyzes of plasma β-amyloid levels (Aβ1–40 and Aβ1–42), oxidative stress markers (glutathione peroxidase, superoxide dismutase, and malondialdehyde (MDA)), and astrocytic reactivity by glial fibrillary acidic protein (GFAP) levels. The results showed no statistically significant differences in behavior between aftin-4 treated, aged and control mice. In aftin-4 treated mice, we observed lower brain MDA levels and higher plasma concentrations of Aβ1–42. The Aβ1–42/Aβ1–40 ratio was comparable in all groups. Qualitative Western blot analysis of GFAP expression showed more intense bands in aged and aftin-4-treated mice, indicating increased astrocytic activation. The effects of aftin-4 and age were not sex-dependent, as no significant interaction was found between sex and experimental group. Our results show that neither the pharmacological model induced with aftin-4 nor the model with aged mice produced measurable cognitive impairment. Furthermore, we investigated the therapeutic potential of MSG-44, a multitarget compound that inhibits butyrylcholinesterase (BChE) and antagonizes α2A-adrenergic receptors. MSG-44 is a pleiotropic carbamate-based prodrug. Its activation is mediated by BChE and leads to a pseudo-irreversible inhibition of the enzyme and the release of atipamezole. The released atipamezole binds to α2A adrenergic receptors and interrupts the hyperphosphorylation cascade of the tau protein. Our study has shown that MSG-44 is suitable for oral administration and can cross the blood-brain barrier. In an aged male mouse model, MSG-44 did not improve cognitive function. This research demonstrates the importance of exploring new therapeutic strategies for AD and the complexity of developing reliable animal models.

• Ključne besede: Mice, Models Animal, Behavior Animal, Cognitive Impairment, Dementia, Alzheimer Disease, Amyloid, Aftin-4, Oxidative Stress, Butyrylcholinesterase, Atipamezole, Adrenergic Receptors