The NKCC1 ion transporter modulates microglial phenotype and inflammatory response to brain injury in a cell-autonomous manner

Krisztina Tóth; Nikolett Lénárt; Péter Berki; Rebeka Fekete; Eszter Szabadits; Balázs Pósfai; Csaba Cserép; Ahmad Alatshan; Szilvia Benkő; Dániel Kiss; Christian A Hübner; Attila Gulyás; Kai Kaila; Zsuzsanna Környei; Ádám Dénes

doi:10.1371/journal.pbio.3001526

The NKCC1 ion transporter modulates microglial phenotype and inflammatory response to brain injury in a cell-autonomous manner

PLoS Biol. 2022 Jan 27;20(1):e3001526. doi: 10.1371/journal.pbio.3001526. eCollection 2022 Jan.

Authors

Krisztina Tóth^{1

2}, Nikolett Lénárt¹, Péter Berki^{2

3}, Rebeka Fekete¹, Eszter Szabadits¹, Balázs Pósfai^{1

2}, Csaba Cserép¹, Ahmad Alatshan^{4

5}, Szilvia Benkő^{4

5}, Dániel Kiss⁶, Christian A Hübner⁷, Attila Gulyás³, Kai Kaila⁸, Zsuzsanna Környei¹, Ádám Dénes¹

Affiliations

¹ Momentum Laboratory of Neuroimmunology, Institute of Experimental Medicine, Budapest, Hungary.
² János Szentágothai Doctoral School of Neurosciences, Semmelweis University, Budapest, Hungary.
³ Laboratory of Cerebral Cortex Research, Institute of Experimental Medicine, Budapest, Hungary.
⁴ Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
⁵ Doctoral School of Molecular Cellular and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
⁶ Software Engineering Institute, John von Neumann Faculty of Informatics, Óbuda University, Budapest, Hungary.
⁷ University Hospital Jena, Friedrich Schiller University, Jena, Germany.
⁸ Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland.

Abstract

The NKCC1 ion transporter contributes to the pathophysiology of common neurological disorders, but its function in microglia, the main inflammatory cells of the brain, has remained unclear to date. Therefore, we generated a novel transgenic mouse line in which microglial NKCC1 was deleted. We show that microglial NKCC1 shapes both baseline and reactive microglia morphology, process recruitment to the site of injury, and adaptation to changes in cellular volume in a cell-autonomous manner via regulating membrane conductance. In addition, microglial NKCC1 deficiency results in NLRP3 inflammasome priming and increased production of interleukin-1β (IL-1β), rendering microglia prone to exaggerated inflammatory responses. In line with this, central (intracortical) administration of the NKCC1 blocker, bumetanide, potentiated intracortical lipopolysaccharide (LPS)-induced cytokine levels. In contrast, systemic bumetanide application decreased inflammation in the brain. Microglial NKCC1 KO animals exposed to experimental stroke showed significantly increased brain injury, inflammation, cerebral edema and worse neurological outcome. Thus, NKCC1 emerges as an important player in controlling microglial ion homeostasis and inflammatory responses through which microglia modulate brain injury. The contribution of microglia to central NKCC1 actions is likely to be relevant for common neurological disorders.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Brain Edema / chemically induced
Brain Edema / genetics*
Brain Edema / metabolism
Brain Edema / pathology
Brain Injuries / chemically induced
Brain Injuries / genetics*
Brain Injuries / metabolism
Brain Injuries / pathology
Bumetanide / pharmacology
Embryo, Mammalian
Gene Expression Regulation
Hippocampus / drug effects
Hippocampus / metabolism
Hippocampus / pathology
Inflammasomes / drug effects
Inflammasomes / metabolism
Inflammation
Injections, Intraventricular
Interleukin-1beta / genetics
Interleukin-1beta / metabolism
Lipopolysaccharides / administration & dosage
Male
Mice
Mice, Inbred C57BL
Mice, Knockout
Microglia / drug effects
Microglia / metabolism*
Microglia / pathology
NLR Family, Pyrin Domain-Containing 3 Protein / genetics
NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
Neural Stem Cells / drug effects
Neural Stem Cells / metabolism
Neural Stem Cells / pathology
Phenotype
Solute Carrier Family 12, Member 2 / deficiency
Solute Carrier Family 12, Member 2 / genetics*
Stroke / chemically induced
Stroke / genetics*
Stroke / metabolism
Stroke / pathology

Substances

IL1B protein, mouse
Inflammasomes
Interleukin-1beta
Lipopolysaccharides
NLR Family, Pyrin Domain-Containing 3 Protein
Nlrp3 protein, mouse
Slc12a2 protein, mouse
Solute Carrier Family 12, Member 2
Bumetanide

Grants and funding

This work was supported by “Momentum” research grant from the Hungarian Academy of Sciences (LP2016-4/2016 to A.D.; https://mta.hu/lendulet) and ERC-CoG 724994 (to A.D.; https://erc.europa.eu/), with contribution from 2019-2.1.7-ERA-NET-2020-00004 (https://nkfih.gov.hu). Additionally, this work was funded by Hungarian National Scientific Research Fund (NKFIH-OTKA Grant No. K131844 to S.B.), the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (to C.C. and N.L., BO/00558/19/5; https://mta.hu/bolyai-osztondij/bolyai-janos-kutatasi-osztondij-105319), ÚNKP-20-3-II (to B.P.) and ÚNKP-21-5 (to C.C. and N.L.; http://www.unkp.gov.hu/unkp-rol) of the New National Excellence Program of the Ministry for Innovation and Technology, Hungary; German Research Foundation (SPP 1665; https://www.dfg.de/en/) and the Federal Ministry of Education and Research (NEURON ACRoBAT 01EW1706) to C.A.H.; and the Academy of Finland and Sigrid Jusélius Foundation (https://www.sigridjuselius.fi/en/) to K.K.. Prepared with the professional support of the Doctoral Scholarship Program of the Cooperative Doctoral Program of the Ministry of Innovation and Technology Financed from The National Research, Development and Innovation Fund (to B.P.). A.A. holds a Stipendium Hungaricum Scholarship from the Government of Hungary (https://stipendiumhungaricum.hu/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.