Dissertation committee:
Γοργούλης Βασίλης, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Πάντος Κωνσταντίνος, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Κουλούκουσα-Γιαννιού Μυρσίνη, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Ευαγγέλου Κωνσταντίνος, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑς
Χαβάκη Σοφία (Επιβλέπουσα), Επίκουρη Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Πατέρας Ιωάννης, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Μουρούζης Ιορδάνης, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Summary:
Cellular senescence is an essentially irreversible cell-cycle arrest that can be an alarm response instigated by numerous stressors, including exposure to genotoxic agents, nutrient deprivation. It is a cell state implicated in various physiological processes and a wide range of age-related diseases and contributes to organismal development, aging, and diverse pathologies. Senescence is, also, important as an anti-tumour barrier to carcinogenesis. However, if tissue damage continues and macrophage attraction is reduced, senescent cells are not able to inhibit adenoma development and carcinogenesis, creating an environment conducive to tumor growth.To date, the most widely used method to detect senescent cells is Senescence- associated b-galactosidase activity (SA-b-gal) assay. This biomarker, however, has many disadvantages, making it increasingly difficult to study senescence in various cellular systems. Recently, it has been reported specific recognition of senescent cells in biological material including cultured cells, fresh/frozen, and archival (formalin-fixed and paraffin-embedded, FFPE) tissues, applying the Sudan Black B (SBB) histochemical dye. SBB reacts with lipofuscin, a non degradable aggregate of oxidized proteins, lipids, and metals. Lipofuscin accumulates in senescent cells, as a by- product of the senescent process, and should be considered as a new ‘hallmark’ of senescence. There was, therefore, a scientific idea to synthesize new chemical compounds, which detect lipofuscin, and therefore senescent cells. We designed and synthesized a lipophilic, biotin-linked Sudan Black B (SBB) analogue, GL13, suitable for sensitive and specific, antibody-enhanced detection of lipofuscin-containing senescent cells in any biological material. This new hybrid histo-/immunochemical method is easy to perform, reliable, and universally applicable to assess senescence in biomedicine, from cancer research to gerontology.During the doctoral dissertation, the phenomenon of cellular senescence in the blood serum of healthy and pathological samples was also examined, measuring the levels of lipofuscin. The healthy were classified into two categories depending on age, while the patients were classified according to the disease from which they suffer. The diseases that were examined were heart failure, rheumatoid arthritis, cancer and neurodegenerative diseases.The aim of these experiments was to investigate whether lipofuscin levels in blood serum vary according to age and in what percentage, as well as whether these levels change in some diseases, possibly indicating lipofuscin as a future prognosis biomarker.
