Microglial P2Y6 calcium signaling promotes phagocytosis and shapes neuroimmune responses in epileptogenesis

Anthony D Umpierre; Bohan Li; Katayoun Ayasoufi; Whitney L Simon; Shunyi Zhao; Manling Xie; Grace Thyen; Benjamin Hur; Jiaying Zheng; Yue Liang; Dale B Bosco; Mark A Maynes; Zhaofa Wu; Xinzhu Yu; Jaeyun Sung; Aaron J Johnson; Yulong Li; Long-Jun Wu

doi:10.1016/j.neuron.2024.03.017

Microglial P2Y₆ calcium signaling promotes phagocytosis and shapes neuroimmune responses in epileptogenesis

Neuron. 2024 Apr 10:S0896-6273(24)00195-8. doi: 10.1016/j.neuron.2024.03.017. Online ahead of print.

Authors

Anthony D Umpierre¹, Bohan Li², Katayoun Ayasoufi³, Whitney L Simon⁴, Shunyi Zhao⁵, Manling Xie⁶, Grace Thyen⁶, Benjamin Hur⁷, Jiaying Zheng⁶, Yue Liang⁶, Dale B Bosco⁶, Mark A Maynes⁴, Zhaofa Wu², Xinzhu Yu⁸, Jaeyun Sung⁷, Aaron J Johnson⁹, Yulong Li¹⁰, Long-Jun Wu¹¹

Affiliations

¹ Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA. Electronic address: umpierre.anthony@mayo.edu.
² State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China.
³ Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA.
⁴ Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, USA.
⁵ Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, USA.
⁶ Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
⁷ Center for Individualized Medicine, Mayo Clinic, Rochester, MN 55905, USA; Department of Surgery, Mayo Clinic, Rochester, MN 55905, USA.
⁸ Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
⁹ Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA.
¹⁰ State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China. Electronic address: yulongli@pku.edu.cn.
¹¹ Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA; Department of Immunology, Mayo Clinic, Rochester, MN 55905, USA; Center for Neuroimmunology and Glial Biology, Institute of Molecular Medicine, University of Texas Health Science Center, Houston, TX 77030, USA. Electronic address: longjun.wu@uth.tmc.edu.

PMID: 38614103
DOI: 10.1016/j.neuron.2024.03.017

Abstract

Microglial calcium signaling is rare in a baseline state but strongly engaged during early epilepsy development. The mechanism(s) governing microglial calcium signaling are not known. By developing an in vivo uridine diphosphate (UDP) fluorescent sensor, GRAB_UDP1.0, we discovered that UDP release is a conserved response to seizures and excitotoxicity across brain regions. UDP can signal through the microglial-enriched P2Y₆ receptor to increase calcium activity during epileptogenesis. P2Y₆ calcium activity is associated with lysosome biogenesis and enhanced production of NF-κB-related cytokines. In the hippocampus, knockout of the P2Y₆ receptor prevents microglia from fully engulfing neurons. Attenuating microglial calcium signaling through calcium extruder ("CalEx") expression recapitulates multiple features of P2Y₆ knockout, including reduced lysosome biogenesis and phagocytic interactions. Ultimately, P2Y₆ knockout mice retain more CA3 neurons and better cognitive task performance during epileptogenesis. Our results demonstrate that P2Y₆ signaling impacts multiple aspects of myeloid cell immune function during epileptogenesis.

Keywords: CalEx; GRAB sensor; P2Y6; UDP; calcium signaling; inflammation; microglia; phagocytosis; purine; seizures.