KCC2 is required for the survival of mature neurons but not for their development

Autor: Shu Fun Josephine Ng, Jack H. Howden, Christopher E. Bope, Miguel A. Rodriguez Santos, Jake S. Dengler, Matt R. Kelley, Qiu Ren, Paul Davies, Ross A. Cardarelli, Catherine Choi, Josef T. Kittler, Joshua L. Smalley, Stephen J. Moss, Georgina Kontou, Nicholas J. Brandon
Rok vydání: 2021
Předmět:
Male
0301 basic medicine
Programmed cell death
Neurogenesis
KCC2
Poly ADP ribose polymerase
Primary Cell Culture
TLE
temporal lobe epilepsy

Apoptosis
Biochemistry
Epileptogenesis
Mice
03 medical and health sciences
chemistry.chemical_compound
AAV
adeno-associated virus

Chlorides
Receptors
GABA

Seizures
Animals
TTX
tetrodotoxin

Receptor
Molecular Biology
gamma-Aminobutyric Acid
GFP
green fluorescent protein

Mice
Knockout

Neurons
KO
knockout

Symporters
030102 biochemistry & molecular biology
PARP
poly (ADP-ribose) polymerase (PARP)

Cell Biology
KCC2
K+/Cl− cotransporter 2

DIV
days in vitro

Cell biology
Mice
Inbred C57BL

cell death
030104 developmental biology
nervous system
chemistry
Potassium
Tetrodotoxin
Female
extrinsic pathway
Cotransporter
GABAAR
γ-aminobutyric acid type A receptors

Intracellular
Research Article
Zdroj: The Journal of Biological Chemistry
ISSN: 0021-9258
Popis: The K+/Cl− cotransporter KCC2 (SLC12A5) allows mature neurons in the CNS to maintain low intracellular Cl− levels that are critical in mediating fast hyperpolarizing synaptic inhibition via type A γ-aminobutyric acid receptors (GABAARs). In accordance with this, compromised KCC2 activity results in seizures, but whether such deficits directly contribute to the subsequent changes in neuronal structure and viability that lead to epileptogenesis remains to be assessed. Canonical hyperpolarizing GABAAR currents develop postnatally, which reflect a progressive increase in KCC2 expression levels and activity. To investigate the role that KCC2 plays in regulating neuronal viability and architecture, we have conditionally ablated KCC2 expression in developing and mature neurons. Decreasing KCC2 expression in mature neurons resulted in the rapid activation of the extrinsic apoptotic pathway. Intriguingly, direct pharmacological inhibition of KCC2 in mature neurons was sufficient to rapidly induce apoptosis, an effect that was not abrogated via blockade of neuronal depolarization using tetrodotoxin (TTX). In contrast, ablating KCC2 expression in immature neurons had no discernable effects on their subsequent development, arborization, or dendritic structure. However, removing KCC2 in immature neurons was sufficient to ablate the subsequent postnatal development of hyperpolarizing GABAAR currents. Collectively, our results demonstrate that KCC2 plays a critical role in neuronal survival by limiting apoptosis, and mature neurons are highly sensitive to the loss of KCC2 function. In contrast, KCC2 appears to play a minimal role in mediating neuronal development or architecture.
Databáze: OpenAIRE