Naslov
Cell growth or apoptosis: decision by GM3 ganglioside in partial hepatectomy model

Autori
Čikeš Čulić, Vedrana ; Tičinović Kurir, Tina ; Zemunik, Tatijana ; Grković, Ivica ; Terzić, Janoš ; Markotić, Anita

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Congress of the Croatian Society of Biochemistry and Molecular Biology with international participation : HDBMB2008 : Book of Abstracts / Strelec, Ivica ; Glavaš-Obrovac, Ljubica - Osijek : Hrvatsko Društvo za Biotehnologiju, 2008, 42-42

ISBN
978-953-95551-2-0

Skup
Congress of the Croatian Society of Biochemistry and Molecular Biology with international participation

Mjesto i datum
Osijek, Hrvatska, 17.09.2008. - 20.09.2008

Vrsta sudjelovanja
Pozvano predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
liver regeneration; hyperbaric oxygenation; gangliosides; apoptosis; ceramide

Sažetak
Rats treated with hyperbaric oxygen before partial hepatectomy (preHBO) shows the highest expression of GM3 gangliosides compared to animals oxygenated after operation and to non-oxygenated operated animals. In the same time, preHBO group has the best liver regeneration parameters (liver mass and body mass ratio, blood transaminase levels and liver tissue lipid peroxide level). It is known that GM3 interferes with cell signalling of epidermal growth factor (EGF), one of the most important mediators that induce liver regeneration, inhibiting autophosphorylation of its membrane receptor. Thereby, the result of higher GM3 expression and enhanced regeneration is unexpected in preHBO group. Our presumption was that GM3 in preHBO group would mainly be found in hepatocytes cytosol, from that location it cannot express the inhibitory effect on EGF receptor, which is located in plasma membrane. Therefore, the aim of the present study was to detect immunohistochemically GM3 expression and distribution in hepatocytes of animals expossed to different oxygen treatments (pre- and post-operative) after a partial hepatectomy. Additional aim was to analyse GM3 precursors, ceramide (Cer) monohexaosylceramide and lactosylceramide (LacCer) due to their possible role in apoptosis. The experiment was performed using exactly the same rat model which previously showed increased GM3 expression and more efficient liver regeneration. Frozen liver sections were analysed with confocal microscopy after staining with GM3 specific antibody, with or without hepatocyte membrane permeabilization. Ganglioside precursors, Cer, monohexaosylceramide and (LacCer) were determined by high perfomance thin layer chromatography. Apoptosis was assessed by fluorescein-dUTP end-labeling of fragmented DNA. Liver of pre-operative oxygenated rats showed high perinuclear expression of GM3 which was absent in post-operative oxygenated and control animals. In the same group Cer content was lower, monohexaosylceramide and LacCer were absent, and content of apoptotic cells was significantly the lowest, compared to other groups examined (F=20.36, p=0.0001). These findings indicate that GM3 ganglioside may be involved in mediation of beneficial effects of pre-operatively oxygenation during the liver regeneration.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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