Distribucija botulinum toksina u središnjem živčanom sustavu

master's thesis

• Title (english): Distribution of botulinum toxin in the central nervous system
• Author: Barbara Komar
• Mentor: Lidija Bach-Rojecky (mentor)
• Committee member: Lidija Bach-Rojecky (predsjednik povjerenstva)
• Committee member: Anita Hafner (član povjerenstva)
• Committee member: Sandra Šupraha-Goreta (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmacology); Zagreb
• Defense date and country: 2022-10-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Botulinum toksin tipa A je neurotoksični protein koji proizvodi anaerobna bakterija Clostridium botulinum,
te predstavja jedan od najsmrtonosnijih otrova u prirodi. Mehanizam djelovanja BoNT/A uključuje
cijepanje proteina SNAP-25 koji ima ključnu ulogu u egzocitozi acetilkolina na krajevima aksona, te
posljedično svoje djelovanje manifestira nastankom mlohane paralize mišića. Tijekom godina bazičnih
istraživanja, pokazano je da toksin osim na motoričke neurone, također djeluje i na senzorne neurone te
tako interferira s prijenosom bolnih signala, što za posljedicu može imati izniman klinički značaj.
Kontroliranom primjenom u pikomolarnim dozama toksin se koristi u terapiji stanja koja su uzrokovana
hiperaktivnosti mišića, kao što su cervikalna distonija, strabizam, hiperhidroza, ali i u terapiji kroničnih
migrena. Brojna istraživanja su rađena istražujući dodatne mogućnosti primjene BoNT/A u kliničke svrhe,
između ostalog i u terapiji kronične boli, čije je liječenje do sad predstavljalo veliki izazov. Cilj ovog
diplomksog rada bio je ispitati distribuciju botulinum toksina u različitim regijama mozga nakon njegove
primjene u cisternu magnu. Eksperimenti su provedeni na mužjacima štakora Wistar na Zavodu za
farmakologiju Medicinskog fakulteta Sveučilišta u Zagrebu u skladu s s aktualim propisima i Zakonom o
zaštiti životinja. Nakon iniciranja 5 i.j./kg BoNT/A u cisternu magnu, prikupljeni su uzorci tkiva mozgova i
pripremljeni za imunohistokemijsku analizu. Pratila se prisutnost pocijepanog SNAP-25 proteina kao
pokazatelja prisutnost toksina, u različitim regijama mozga.Dobiveni rezultati ukazuju na prisutnost toksina
u neposrednoj blizini mjesta iniciranja, u područjima trigeminalnog nucleus caudalisaihipokampusa, ali i u
udaljenim regijama mozga. Ovi nalazi zahtjevaju daljnja istraživanja kako bi se objasnili načini distribucije
toksina u udaljenija područja te njihovo značenje za djelovanje toksina, posebice u kliničkom okruženju.

Abstract (english)

Botulinum toxin type A is a neurotoxic protein produced by the anaerobic bacterium Clostridium
botulinum, and is one of the deadliest poisons in nature. The mechanism of action of BoNT/A involves the
cleavage of the SNAP-25 protein, which plays a key role in the exocytosis of acetylcholine at the ends of
axons, and consequently manifests its action in the occurrence of flaccid muscle paralysis. During the years
of basic research, it was shown that the toxin not only acts on motor neurons, but also on sensory neurons
and thus interferes with the transmission of pain signals, which as a result can have exceptional clinical
significance. With controlled application in picomolar doses, the toxin is used in the treatment of conditions
caused by muscle hyperactivity, such as cervical dystonia, strabismus, hyperhidrosis, but also in the
treatment of chronic migraines. Numerous studies have been conducted investigating the additional
possibilities of using BoNT/A for clinical purposes, among others in the therapy of chronic pain, the
treatment of which has been a great challenge so far. The aim of this thesis was to examine the distribution
of botulinum toxin in different regions of the brain after its application to the cisterna magna. The
experiments were conducted on male Wistar rats at the Department of Pharmacology, Faculty of Medicine,
University of Zagreb, in accordance with current regulations and the Animal Protection Act. After the
initiation of 5 IU/kg BoNT/A into the cisterna magna, brain tissue samples were collected and prepared for
immunohistochemical analysis. The presence of cleaved SNAP-25 protein was monitored as an indicator of
the presence of toxins in different regions of the brain. The obtained results indicate the presence of toxins
in the immediate vicinity of the initiation site, in the areas of the trigeminal nucleus of the caudalis and
hippocampus, but also in distant regions of the brain. These findings require further research to explain the
ways of toxin distribution to more distant areas and their significance for the action of the toxin, especially
in the clinical setting.

• Keywords: Botulinum toksin; pocijepani SNAP-25 protein; imunohitokemijska analiza; središnji živčani sustav
• Keywords (english): Botulinum toxin; cleaved SNAP-25 protein; immunocytochemical analysis; central nervous system
• Language: croatian
• URN:NBN: urn:nbn:hr:163:448449
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2024-10-28
• Created on: 2022-11-03 15:57:52