Osmotic Response of Dorsal Root Ganglion Neurons Expressing Wild-Type and Mutant KCC3 Transporters
Open Access
- 7 June 2020
- journal article
- Published by Cell Physiol Biochem Press GmbH and Co KG in Cellular Physiology and Biochemistry
- Vol. 54 (4), 577-590
- https://doi.org/10.33594/000000241
Abstract
Loss-of-Function (LOF) of the potassium chloride cotransporter 3 (KCC3) results in hereditary sensorimotor neuropathy with Agenesis of the Corpus Callosum (HSMN/ACC). Our KCC3 knockout mouse recapitulated axonal swelling and tissue vacuolization observed in autopsies of individuals with HSMN/ACC. We previously documented the first human case of a KCC3 gain-of-function (GOF) in which the patient also exhibited severe peripheral neuropathy. Furthermore, the GOF mouse model exhibited shrunken axons implicating the cotransporter in cell volume homeostasis. It is unclear how both KCC3 LOF and GOF lead to peripheral neuropathy. Thus, we sought to study differences in cell volume regulation of dorsal root ganglion neurons isolated from different mouse lines. Using wide-field microscopy, we measured calcein fluorescence intensity through pinhole measurements at the center of cells and compared cell swelling and cell volume regulation/recovery of wild-type, LOF, and GOF dorsal root ganglia neurons, as well as wild-type neurons treated with a KCC-specific inhibitor. In contrast to control neurons that swell and volume regulate under a hypotonic challenge, neurons lacking KCC3 swell but fail to volume regulate. Similar data were observed in wild-type neurons treated with the KCC inhibitor. We also show that sensory neurons expressing a constitutively active KCC3 exhibited a blunted swelling phase compared to wild-type neurons, questioning the purely osmotic nature of the swelling phase. These findings demonstrate the integral role of KCC3 in cell volume homeostasis and support the idea that cell volume homeostasis is critical to the health of peripheral nerves.This publication has 31 references indexed in Scilit:
- Sites of Regulated Phosphorylation that Control K-Cl Cotransporter ActivityCell, 2009
- Small-molecule screen identifies inhibitors of the neuronal K-Cl cotransporter KCC2Proceedings of the National Academy of Sciences of the United States of America, 2009
- Physiology of Cell Volume Regulation in VertebratesPhysiological Reviews, 2009
- Axonal and periaxonal swelling precede peripheral neurodegeneration in KCC3 knockout miceNeurobiology of Disease, 2007
- Distal truncation of KCC3 in non–French Canadian HMSN/ACC familiesNeurology, 2007
- The K–Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosumNature Genetics, 2002
- Fine mapping the candidate region for peripheral neuropathy with or without agenesis of the corpus callosum in the French Canadian populationEuropean Journal of Human Genetics, 2002
- Localization of the K+–Cl− cotransporter, KCC3, in the central and peripheral nervous systems: expression in the choroid plexus, large neurons and white matter tractsNeuroscience, 2001
- Kinetics of activation and inactivation of swelling-stimulated K+/Cl- transport. The volume-sensitive parameter is the rate constant for inactivation.The Journal of general physiology, 1990
- Ion Permeability of Phospholipid BilayersNature, 1972