P2Y6 Receptors Inhibit Astroglia Proliferation in Cultures with Activated Microglia

Field: Neuroscience (Life Sciences)

Event Abstract Back to Event P2Y6 Receptors Inhibit Astroglia Proliferation in Cultures with Activated Microglia Clara Quintas1*, Joao Magalhaes1, Jorge Goncalves1 and Gloria Queiroz1 1 Faculty of Pharmacy, University of Porto, Laboratory of Pharmacology, REQUIMTE, Portugal In the CNS, activation of P2 receptors triggers astrogliosis (Franke et al., 2006, Eur. J. Physiol. 452: 622-644), which is a response to injury and inflammation modulated by trophic factors and cytokines released by microglia (Röhl et al., 2007, Brain Res. 1129: 43-52). P2 pyrimidine receptors are activated by uridine nucleotides released from astrocytes (Lazarowski et al., 2006, Novartis Found. Symp. 276: 73-84) and play an important role in activated microglia, triggering phagocytosis and the release of cytokines (Koizumi et al., 2007, Nature 446, 1091-1095). However, the influence of these receptors in the astrogliosis is not fully understood. In the present work we investigated the influence of uridine nucleotides on glial proliferation in cultures of astrocytes and co-cultures of astrocytes with activated microglia, in order to clarify the role of P2 pyrimidine receptors in the astrocyte-microglia signalling.Primary cultures of astrocytes and co-cultures with activated microglia (LPS cultures, obtained by treatment with 100 ng/ml LPS) were prepared from brain cortex of newborn rats. Astrocytes and microglia were labelled with anti-GFAP or anti-OX42 antibodies, respectively. Effects of uridine nucleotides on cell proliferation were measured by methyl-[3H]-thymidine incorporation and its metabolism in the cultures was evaluated by HPLC- UV. LDH release and staining of nuclear chromatin with Hoechst dye were used to estimate effects on cell viability.In LPS cultures, but not in cultures of astrocytes, UTP and UDP (0.001-1 mM) inhibited cell proliferation up to 43 ± 3% (n=8, P<0.05). UTP (0.1 mM, n=4) was metabolised within 1h into 68.6 ± 8.7 µM UDP. The inhibitory effect of UTP (0.1 mM; 35 ± 2%; n=6, P<0.05) was antagonised by the P2Y6 antagonist MRS 2578 (1 µM; 10 ± 5%; n=6, P<0.05) and mimicked by the P2Y6 agonist PBS 0474 (0.1 µM). UTP and UDP (both at 1 mM) did not change LDH release or the % of apoptotic nuclei in the cultures. In the presence of the NTPDase inhibitor ARL 67156, UTP (0.1 mM) increased cell proliferation by 48 ± 8% (n=6, P<0.05), an effect mimicked by the more stable analogue UTPγS (100 µM; 37 ± 6%, n=4, P<0.05) and prevented by suramin.In astroglia cultures with activated microglia P2Y2/4 receptor-induced cell proliferation is prevented by a high rate of UTP metabolism into UDP which activates P2Y6 receptors and inhibits astrocyte proliferation by a mechanism that does not involve cell death. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Poster Presentation Citation: Quintas C, Magalhaes J, Goncalves J and Queiroz G (2009). P2Y6 Receptors Inhibit Astroglia Proliferation in Cultures with Activated Microglia. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.055 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 06 Aug 2009; Published Online: 06 Aug 2009. * Correspondence: Clara Quintas, Faculty of Pharmacy, University of Porto, Laboratory of Pharmacology, REQUIMTE, Porto, Portugal, claraquintas@ff.up.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Clara Quintas Joao Magalhaes Jorge Goncalves Gloria Queiroz Google Clara Quintas Joao Magalhaes Jorge Goncalves Gloria Queiroz Google Scholar Clara Quintas Joao Magalhaes Jorge Goncalves Gloria Queiroz PubMed Clara Quintas Joao Magalhaes Jorge Goncalves Gloria Queiroz Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.