Astroglial Ca2+ signaling is generated by the coordination of IP3R and store-operated Ca2+ channels

Shigeo Sakuragi, Fumihiro Niwa, Yoichi Oda, Katsuhiko Mikoshiba, Hiroko Bannai

    Research output: Contribution to journalArticlepeer-review

    11 Citations (Scopus)

    Abstract

    Astrocytes play key roles in the central nervous system and regulate local blood flow and synaptic transmission via intracellular calcium (Ca2+) signaling. Astrocytic Ca2+ signals are generated by multiple pathways: Ca2+ release from the endoplasmic reticulum (ER) via the inositol 1, 4, 5-trisphosphate receptor (IP3R) and Ca2+ influx through various Ca2+ channels on the plasma membrane. However, the Ca2+ channels involved in astrocytic Ca2+ homeostasis or signaling have not been fully characterized. Here, we demonstrate that spontaneous astrocytic Ca2+ transients in cultured hippocampal astrocytes were induced by cooperation between the Ca2+ release from the ER and the Ca2+ influx through store-operated calcium channels (SOCCs) on the plasma membrane. Ca2+ imaging with plasma membrane targeted GCaMP6f revealed that spontaneous astroglial Ca2+ transients were impaired by pharmacological blockade of not only Ca2+ release through IP3Rs, but also Ca2+ influx through SOCCs. Loss of SOCC activity resulted in the depletion of ER Ca2+, suggesting that SOCCs are activated without store depletion in hippocampal astrocytes. Our findings indicate that sustained SOCC activity, together with that of the sarco-endoplasmic reticulum Ca2+-ATPase, contribute to the maintenance of astrocytic Ca2+ store levels, ultimately enabling astrocytic Ca2+ signaling.

    Original languageEnglish
    Pages (from-to)879-885
    Number of pages7
    JournalBiochemical and biophysical research communications
    Volume486
    Issue number4
    DOIs
    Publication statusPublished - 2017 May 13

    Keywords

    • Astrocyte
    • Ca signal
    • Endoplasmic reticulum
    • IP receptor
    • SOC channel

    ASJC Scopus subject areas

    • Biophysics
    • Biochemistry
    • Molecular Biology
    • Cell Biology

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