Prijenos proteina APP u organelima endocitoznog puta u stanicama CHO NPC1-null

master's thesis

• Title (english): Transport of APP protein in organelles of endocytic pathway in CHO NPC1-null cells
• Author: Ana Lisica
• Mentor: Silva Katušić Hećimović (mentor)
• Mentor: Dubravka Hranilović (sumentor)
• Committee member: Silva Katušić Hećimović (predsjednik povjerenstva)
• Committee member: Dubravka Hranilović (član povjerenstva)
• Committee member: Željka Vidaković Cifrek (član povjerenstva)
• Committee member: Maja Matulić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2009, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Promijenjen metabolizam i povećana sinteza peptida amiloid β (Aβ) smatra se ključnim događajem u razvoju Alzheimerove bolesti (AB). Nedavna istraživanja su pokazala da razina kolesterola utječe na procesiranje prekursora proteina amiloid β (APP), te utječe na stvaranje i razinu peptida Aβ. Nakupljanje kolesterola i značajno povećanje razine peptida Aβ uočeno je i u Niemann Pickovoj bolesti tipa C (NPC), nasljednoj bolesti nakupljanja lipida, pa se ova bolest pokazala kao dobar model u proučavanju mehanizma djelovanja kolesterola na razvoj AB. Cilj rada je bio ispitati utječe li nakupljanje kolesterola u bolesti NPC na promijenjen smještaj proteina APP i presenilina 1 (PS1) u staničnim organelima endocitoznog puta. Korištenjem modelnih stanica CHO NPC1-/- i stanica divljeg tipa (CHOwt), pokazano je da stanice CHO NPC1-/- pokazuju promijenjen smještaj proteina APP u ranim i reciklirajućim endosomima. Stanice CHO NPC1-/- pokazuju promijenjeno bojanje biljega za rane i reciklirajuće endosome što ukazuje na njihovo nakupljanje na periferiji stanice. Međutim nije pokazan promijenjen smještaj proteina PS1 u organelima endocitoznog puta. Ovi rezultati ukazuju da bi kolesterol mogao djelovati na nastanak AB tako da regulira smještaj proteina APP unutar staničnih organela endocitoznog puta, te da takva preraspodjela proteina APP dovodi do povećanog stvaranja odsječka C99, te peptida Aβ u ovim organelima.

Abstract (english)

Altered metabolism and increased formation of amyloid-β peptide (Aβ) is considered to be the key event in development of Alzheimer's disease (AD). Recent reports have shown that cholesterol levels modulate processing of amyloid-β precursor protein (APP) and formation of Aβ peptide. Cholesterol accumulation and increased levels of Aβ peptide have also been observed in Niemann-Pick type C disease (NPC), hereditary sphingolipid storage disorder, which has become an important model to study the role of cholesterol in the pathogenesis of AD. The goal of this work was to investigate whether cholesterol accumulation in NPC disease changes distribution of APP protein and presenilin 1 (PS1) within endocytic pathway. Using immunoconfocal microscopy, we observed altered localization of APP protein in early and recycling endosomes in CHO NPC1-/- compared to CHOwt cells. In addition, we detected altered staining of markers for early (EEA1) and recycling (transferrin receptor, TFR) endosomes in CHO NPC1-/- cells, which suggests their accumulation on the cell periphery. However, altered localization of PS1 was not observed in endocytic organelles. These results suggest that cholesterol may influence the onset of AD by regulating trafficking of APP protein within endocytic pathway, and that this redistribution od APP protein leads to increased synthesis of C99, and Aβ peptide in these organelles.

• Keywords: APP; prekursor proteina amiloid beta; kolesterol; bolest NPC; Niemann Pickova bolest tipa C; Alzheimerova bolest
• Keywords (english): APP; beta-amyloid precursor protein; cholesterol; NPC disease; Niemann-Pick type C; Alzheimer's disease
• Language: croatian
• URN:NBN: urn:nbn:hr:217:523653
• Study programme: Title: Integrated undergraduate and graduate university study of Biology and Chemistry Education; specializations in: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Course: Integrated undergraduate and graduate university study of Biology and Chemistry Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije biologije i kemije (magistar/magistra edukacije biologije i kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-03-13 11:06:13