Microglial SWELL1 deficiency drives male-specific seizure vulnerability but paradoxical neuroprotection through impaired phagocytosis
Abhijeet S. Barath, Aastha Dheer, Laura Montier, Mekenzie M Peshoff, Emily Dale, Flavia Goche, Thanh Thanh Le Nguyen, Mastura Akter, FangFang Qi, Dimitrios Kleidonas, Lauren Harris, Sarah A. Jewanee, Anthony D. Umpierre, Dale B. Bosco, Koichiro Haruwaka, Rajan Sah, Long-Jun Wu
Abhijeet S. Barath, Aastha Dheer, Laura Montier, Mekenzie M Peshoff, Emily Dale, Flavia Goche, Thanh Thanh Le Nguyen, Mastura Akter, FangFang Qi, Dimitrios Kleidonas, Lauren Harris, Sarah A. Jewanee, Anthony D. Umpierre, Dale B. Bosco, Koichiro Haruwaka, Rajan Sah, Long-Jun Wu
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Research Article Immunology Neuroscience

Microglial SWELL1 deficiency drives male-specific seizure vulnerability but paradoxical neuroprotection through impaired phagocytosis

Abstract

The discovery of genes encoding the volume-regulated anion channel (VRAC) has enabled detailed exploration of its cell type–specific roles in the brain. LRRC8A (SWELL1) is the essential VRAC subunit. We observed seizure-induced, subunit-specific changes in microglial VRAC expression and investigated its function using conditional KO (cKO) of LRRC8A in microglia. SWELL1 cKO mice exhibited a male-specific increase in kainate-induced seizure severity, yet showed paradoxical neuroprotection against seizure-associated neuronal loss. Mechanistically, SWELL1 deletion led to a cell-autonomous reduction in microglial density and decreased release of VRAC-permeable neuroactive metabolites, including taurine, GABA, and glutamate in culture. Additionally, impaired phagocytic kinetics and reduced lysosomal biogenesis contributed to the observed neuroprotection. These findings reveal potentially novel roles for microglial VRAC in regulating seizure outcomes and microglia-neuron interactions.

Authors

Abhijeet S. Barath, Aastha Dheer, Laura Montier, Mekenzie M Peshoff, Emily Dale, Flavia Goche, Thanh Thanh Le Nguyen, Mastura Akter, FangFang Qi, Dimitrios Kleidonas, Lauren Harris, Sarah A. Jewanee, Anthony D. Umpierre, Dale B. Bosco, Koichiro Haruwaka, Rajan Sah, Long-Jun Wu

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Figure 3

SWELL1 deletion impairs microglial release of neuroactive metabolites.

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SWELL1 deletion impairs microglial release of neuroactive metabolites. (...
(A) Experimental design for activation of SWELL1 (VRAC channel) in purified microglia cultures with a hypotonic stimulus and collection of supernatant for neuromodulator analysis. (B–G) Quantification of taurine, GABA, glutamate, aspartate, adenosine, and ATP levels in supernatant of SWELL1 cKO versus control microglia maintained in isotonic and hypotonic conditions (dot, 1 well; 4–5 wells/genotype; 50,000 microglia/well; statistic: 2-way ANOVA with Bonferroni’s multiple-comparison test). (H) Experimental design to test differences in CSF and plasma metabolites after seizure induction. (I–K) Batch-normalized taurine, GABA, and glutamate levels (statistic: permutation test). LC/MS, liquid chromatography/mass spectrometry; VRAC, volume regulated anion channel. *P <0.05, **P <0.01, ***P <0.005, ****P <0.001.