H2O2-induced Ca2+ influx and its inhibition by N-(p-amylcinnamoyl) anthranilic acid in the beta-cells: involvement of TRPM2 channels
2009 (English)In: Journal of Cellular and Molecular Medicine (Print), ISSN 1582-1838, Vol. 13, no 9B, 3260-3267 p.Article in journal (Refereed) Published
Type 2 melastatin-related transient receptor potential channel (TRPM2), a member of the melastatin-related TRP (transient receptor potential) subfamily is a Ca(2+)-permeable channel activated by hydrogen peroxide (H(2)O(2)). We have investigated the role of TRPM2 channels in mediating the H(2)O(2)-induced increase in the cytoplasmic free Ca(2+) concentration ([Ca(2+)](i)) in insulin-secreting cells. In fura-2 loaded INS-1E cells, a widely used model of beta-cells, and in human beta-cells, H(2)O(2) increased [Ca(2+)](i), in the presence of 3 mM glucose, by inducing Ca(2+) influx across the plasma membrane. H(2)O(2)-induced Ca(2+) influx was not blocked by nimodipine, a blocker of the L-type voltage-gated Ca(2+) channels nor by 2-aminoethoxydiphenyl borate, a blocker of several TRP channels and store-operated channels, but it was completely blocked by N-(p-amylcinnamoyl)anthranilic acid (ACA), a potent inhibitor of TRPM2. Adenosine diphosphate phosphate ribose, a specific activator of TRPM2 channel and H(2)O(2), induced inward cation currents that were blocked by ACA. Western blot using antibodies directed to the epitopes on the N-terminal and on the C-terminal parts of TRPM2 identified the full length TRPM2 (TRPM2-L), and the C-terminally truncated TRPM2 (TRPM2-S) in human islets. We conclude that functional TRPM2 channels mediate H(2)O(2)-induced Ca(2+) entry in beta-cells, a process potently inhibited by ACA.
Place, publisher, year, edition, pages
2009. Vol. 13, no 9B, 3260-3267 p.
Calcium influx, Calcium signalling, Insulin-secreting cells, Microfluorometry, N-(p-amylcinnamoyl)anthranilic acid, TRP channels, TRPM2
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-132137DOI: 10.1111/j.1582-4934.2009.00737.xISI: 000274179300027PubMedID: 19382906OAI: oai:DiVA.org:uu-132137DiVA: diva2:357047