The role of astrocytic NMDAR in the brain physiology and pathology has only begun to be understood. The results of this dissertation demonstrate that the short-term treatment of NMDA caused an increase of intracellular Ca2+ concentration in astrocytes in a way involving NMDA interaction with NMDAR, because the response was blocked by the receptor channel blocker , MK801, and it did not occur in cells with a silenced GluN1 subunit. For the first time , we have shown that NMDA causes an increase of [3H]-MK 801 binding in cultured astrocytes, an effect that can only occur if that receptor has been preactivated. Immunocytochemical analysis confirmed the presence of the GluN1 subunit of NMDAR and revealed its membrane localization in astrocytes, moreover use of specific siRNA for the GluN1 subunit warranted the soecificity oh the obtained result. Additionally, expression of the GluN1 subunit at the protein level was affirmed by Western blot analysis. The long-term exposure of astrocytes to NMDA decreased the expression of three astrolia-specific proteins-glutamine synthetase (GS), aquaporin 4 (AQP4) and Kir4.1. Moreover, downregulation of GS expression was translatedof to the decreased enzyme activity. The abolition of the NMDA-induced changes by silencing the GluN1subunit of NMDAR positively verified the dependence of the changes on specific interaction of NMDA with NMDAR. The dependence of the decrease of GS, AQP4 and Kir4.1 content on the presence of calcium in the incubation medium, indicated that this effect was induced by the ionotropic mechanisms. Moreover , tt has been demonstrates that the mechanisms of regulation by NMDAR differs for astroglia-specific proteins; NMDA treatment increased expression of GLAST mRNA without affecting the ability of astrocytes to D-aspatate uptake (an unmetabolisable Glu analogue). The fact long-term exposure of astrocytes in vitro to NMDA decreased the expression of three astrocytic proteins, critical in maintaining of ion (Kir4.1), water (AQP4) homeostasis and the balance of neurotransmitters (GS), documented the participation of astrocytic NMDAR in the response of astrocytes to the excitotoxic signal.
Operational Program Digital Poland, 2014-2020, Measure 2.3: Digital accessibility and usefulness of public sector information; funds from the European Regional Development Fund and national co-financing from the state budget.
Jan 20, 2020
Oct 30, 2019
Lazarewicz, Jerzy Salińska, Elżbieta
Skowrońska, Marta Albrecht, Jan (Promotor)
Kraśnicka, Zuzanna Albrecht, Jan Mossakowski, Mirosław Jan (1929 - 2001)
Krupska, Olga Zabłocka, Barbara (Promotor)
Bratek, Ewelina Salińska, Elżbieta (Promotor)
Skowrońska-Ochmann, Katarzyna Ziomek, Joanna Banaszek, Agata Polska Akademia Nauk. Muzeum i Instytut Zoologii
Mossakowski, Mirosław Jan (1929 - 2001) Long, D. M. Myers, Ronald E. Rodriguez de Curet, H. Klatzo, Igor