Itove stanice jetre u zdravlju i bolesti

master's thesis

• Title (english): Itus liver cells in health and disease
• Author: Antonio Klemenčić
• Mentor: Ljerka Banek (mentor)
• Committee member: Đurđica Grbeša (predsjednik povjerenstva)
• Committee member: Dinko Mitrečić (član povjerenstva)
• Committee member: Ljerka Banek (član povjerenstva)
• Granter: University of Zagreb; School of Medicine; (Department of Histology and Embryology); Zagreb
• Defense date and country: 2014-07-15, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Basic Medical Sciences; Cytology, Histology and Embryology

Abstract

Zvjezdolike ili Itove stanice jetre smještene su u subendotelnom, perikapilarnom Disseovom prostoru. S njihova tijela pružaju se stanični nastavci koji sadrže mikrotubule i aktinske filamente. Pomoću svojih nastavaka Itove stanice ostvaruju kontakt s hepatocitima i endotelnim stanicama sinusoidnih kapilara.
Itove stanice pohranjuju 50 do 80 % vitamina A u našem tijelu. Zato značajan dio njihove citoplazme sadrži vitamin A u obliku lipidnih kapljica. Osim što imaju ključnu ulogu u metabolizmu vitamina A, one izlučuju citokine i čimbenike rasta, te imaju važnu ulogu u modulaciji imunosnog odgovora jetre. Također sudjeluju u regeneraciji jetre, izlučuju sastojke izvanstaničnog matriksa te omogućuju kontrolu protoka krvi kroz sinusoidne kapilare jetrenog režnjića.
Ove složene funkcije omogućuje im interakcija s njihovim mikrookolišem pomoću različitih vrsta receptora na površini stanične membrane i u jezgri stanica. Među ovim receptorima osobito su zanimljivi receptori za transformacijski čimbenik rasta β i retinoidni receptori.
Prilikom oštećenja jetre, Itove stanice se aktiviraju pri čemu se mijenjaju morfološki i funkcionalno, te dobivaju karakteristike miofibroblasta. U tom obliku, one aktivno sudjeluju u procesu fibroze jetre, što u konačnici dovodi do ciroze i zatajenja jetre. Budući da su terapijske mogućnosti ciroze jetre za sada vrlo ograničene, provodi se niz istraživanja kojima se nastoji pronaći adekvatno terapijsko mjesto djelovanja upravo na Itove stanice, a s ciljem povlačenja same fibroze.

Abstract (english)

Hepatic stellate cells or Ito cells are located in subendothelial, pericapillary space of Disse. Cellular processes, that contain microtubules and actin filaments, extend from cell body. They make contact with neighboring hepatocytes and endothelial cells of sinusoidal capillaries.
Ito cells store 50 to 80 % of vitamin A in organism. That's why significant part of their cytoplasm is consisted of vitamin A in form of lipid droplets. Beside that, they have key role in the metabolism of vitamin A, they secrete cytokines and growth factors and play an important role in modulating the immune response in the liver. They are also involved in the regeneration of the liver, production of extracellular matrix components and control of the blood flow through the sinusoidal capillaries of liver lobules.
These complex functions are enabled by interactions of these cells and their microenvironment through different types of receptors that are located on surface of cell membrane and in nucleus of cell. Among these receptors, especially interesting are receptors for transforming growth factor β (TGF-β) and retinoid receptors.
During liver damage, Ito cells are activated with the functional and morphological change, and receive characteristics of myofibroblasts. In this form, they actively participate in the process of liver fibrosis, which ultimately leads to cirrhosis and liver failure. Since the therapeutic options for liver cirrhosis are still very limited, the aim of series of studies that are currently conducted is to find an adequate therapeutic site of action on Ito cells in order to withdraw the fibrosis.

• Keywords: zvjezdolike stanice jetre; funkcija zvjezdolikih stanica jetre; aktivacija zvjezdolikih stanica jetre; fibroza jetre
• Keywords (english): hepatic stellate cell; function of hepatic stellate cell; activation of hepatic stellate cell; liver fibrosis
• Language: croatian
• URN:NBN: urn:nbn:hr:105:084786
• Study programme: Title: Medicine; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: doktor/doktorica medicine (doktor/doktorica medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2015-10-22 09:51:15