Molekuláris mechanizmusok az elhalt retinális sejtek fagocitózis általi eltávolításaban különbözö fagocita sejtek által-a folyamat szerepe az időskori makula degenerációban
Title in English
Molecular mechanisms of the clearance of retinal dying cells by different phagocytes - implications to age-related macular degeneration
Biological basis of immunity related disorders (e.g. autoimmunity) (Council of Medical and Biological Sciences)
100 %
Panel
Immunity, Cancer and Microbiology
Department or equivalent
Department of Ophthalmology (University of Debrecen)
Starting date
2012-01-01
Closing date
2014-12-31
Funding (in million HUF)
11.964
FTE (full time equivalent)
2.10
state
closed project
Summary in Hungarian
Az utóbbi időben számos vizsgálat indult a fotoreceptor külső szegmentumok retina pigment epithel (RPE) sejtek általi eltávolításának zavarát célozva, azonban egyre inkább valószínűsíthető, hogy a különböző módon (apoptózis, anoikisz, nekrózis, autofágia) elhaló RPE sejtek eltávolításának károsodása is szerepet játszik az időskori macula degeneráció (age-related macular degeneratio, AMD) kialakulásában. Eddig nem ismert, olyan tanulmány, mely in vitro körülmények között a korai majd késői típusú AMD-ben lezajló molekuláris mechanizmusokat vizsgálná az előbb említett elhaló sejtek élő RPE sejtek, makrofágok és éretlen dentritikus sejtek (immature dendritic cells, iDC) általi eltávolítása során. Célunk az RPE sejtek különböző módon való elhalását indukáló in vitro módszerek kidolgozása, és az elhaló RPE sejtek nem professzionális (élő RPE sejtek) és professzionális (makrofágok és iDC-k) fagociták általi eltávolítási dinamizmusának meghatározása; molekuláris szinten a retinában lejátszódó fagocitózis mechanizmus tanulmányozása, valamint különböző gyógyszerek (glukokortikoid triamcinolon, ér-endothel növekedési faktor gátló) fagocitózisra gyakorolt hatása in vitro; a fagocitózist stimuláló molekuláris markerek listájának szűkítése, és funkcióvesztéses vizsgálatok RNA interferencia módszerrel való kivitelezése; in vitro AMD modellünkben megvizsgálni az RPE sejtek fagocitózisa során felszabaduló citokinek sorrendiségét, valamint az inflammoszóma érintettségét a folyamatban, lehetséges terápiás célpontokat keresve.
Summary
Much of the research in the past has focused on studying defects in the clearance of photoreceptor outer segments by retinal pigment epithelium (RPE) as a study model for age-related macular degeneration (AMD). Growing evidence suggests that failure of different dying RPE cells (e.g. apoptotic, anoikic, necrotic and autophagic) to be cleared may also be involved in the development of AMD, along the recognition of the inflamatory nature of this disease. No extensive studies of the molecular players involved in the clearance of these dying cells by the living RPE cells, macrophages or dendritic cells (DCs), resembling early (dry) and late (wet) type of AMD in vitro have been carried out yet. Our aim is to establish, in vitro assay for inducing the different types of death in RPE cells and study the dynamics of their clearance by living RPE cells, macrophages or DCs. We aim to study the molecular mechanisms of the phagocytic process and the effect of different medications (glucocorticoid triamcinolone/vascular-endothelial growth factor inhibitors) at a molecular level. We intend to narrow the selection of experimentally discovered molecular markers-the positive stimulators of phagocytosis, and carry loss-of-function studies on the genes of interest using RNA interference. We strive to assess the role of the cytokines produced during phagocytosis and the involvement of the inflammasome in our in vitro model for AMD with future therapeutic implications.
Final report
Results in Hungarian
Failure to clear out the different dying retinal pigment epithelial (RPE) cells (e.g. apoptotic, anoikic, necrotic and autophagic) can lead to development of age-related macular degeneration (AMD) and background inflammation. No extensive studies of the molecular players involved in the clearance of these dying cells by the living RPE cells, macrophages or dendritic cells (DCs), resembling early (dry) and late (wet) type of AMD in vitro have been carried out yet.
We established an in vitro assay for inducing the different types of death in RPE cells and for studying the dynamics of the clearance by living RPE cells, macrophages or DCs. The mechanisms of the phagocytic process and the effect of medications (glucocorticoid triamcinolone (TC)) could be studied at a molecular level. TC had a profound phagocytosis-enhancing effect on HMDM engulfing anoikic ARPE-19 or hRPE cells, causing a selective upregulation of the Mer tyrosine kinase (MERTK) receptor, while decreasing the expression of the AXL receptor tyrosine kinase and thrombospondin-1 (THSB-1). A narrow selection of experimentally discovered molecular markers - positive stimulators of phagocytosis (e.g. Gas6), and loss-of-function studies on the genes of interest using RNA interference could be performed. The profile of the cytokines/inflammatory pathways induced during phagocytosis were determined in the vitro model for AMD, which may have future therapeutic implications.
Results in English
Failure to clear out the different dying retinal pigment epithelial (RPE) cells (e.g. apoptotic, anoikic, necrotic and autophagic) can lead to development of age-related macular degeneration (AMD) and background inflammation. No extensive studies of the molecular players involved in the clearance of these dying cells by the living RPE cells, macrophages or dendritic cells (DCs), resembling early (dry) and late (wet) type of AMD in vitro have been carried out yet.
We established an in vitro assay for inducing the different types of death in RPE cells and for studying the dynamics of the clearance by living RPE cells, macrophages or DCs. The mechanisms of the phagocytic process and the effect of medications (glucocorticoid triamcinolone (TC)) could be studied at a molecular level. TC had a profound phagocytosis-enhancing effect on HMDM engulfing anoikic ARPE-19 or hRPE cells, causing a selective upregulation of the Mer tyrosine kinase (MERTK) receptor, while decreasing the expression of the AXL receptor tyrosine kinase and thrombospondin-1 (THSB-1). A narrow selection of experimentally discovered molecular markers - positive stimulators of phagocytosis (e.g. Gas6), and loss-of-function studies on the genes of interest using RNA interference could be performed. The profile of the cytokines/inflammatory pathways induced during phagocytosis were determined in the vitro model for AMD, which may have future therapeutic implications.
Goran Petrovski, Réka Albert, Kai Kaarniranta, Morten C. Moe, László Fésüs, András Berta and Dipak K. Das: AUTOPHAGY IN THE EYE: A DOUBLE-EDGED SWORD, Nova Publishers, Book: "Autophagy: Principles, Regulation and Roles in Disease", 2012
Albert R, Kristóf E, Zahuczky G, Szatmári-Tóth M, Veréb Z, Oláh B, Moe MC, Facskó A, Fésüs L, Petrovski G.: Triamcinolone regulated apopto-phagocytic gene expression patterns in the clearance of dying retinal pigment epithelial cells. A key role of Mertk in the enhanced phagocytosis, Biochim Biophys Acta, 2015
