Best1Is a Gene Regulated by Nerve Injury and Required for Ca2+-Activated Cl−Current Expression in Axotomized Sensory Neurons

Abstract

We investigated the molecular determinants of Ca²⁺-activated chloride current (CaCC) expressed in adult sensory neurons after a nerve injury. Dorsal root ganglia express the transcripts of three gene families known to induce CaCCs in heterologous systems: bestrophin, tweety, and TMEM16. We found with quantitative transcriptional analysis andin situhybridization that nerve injury induced upregulation of solely bestrophin-1 transcripts in sensory neurons. Gene screening with RNA interference in single neurons demonstrated that mouseBest1is required for the expression of CaCC in injured sensory neurons. Transfecting injured sensory neurons with bestrophin-1 mutants inhibited endogenous CaCC. Exogenous expression of the fusion protein green fluorescent protein–Bestrophin-1 in naive neurons demonstrated a plasma membrane localization of the protein that generates a CaCC with biophysical and pharmacological properties similar to endogenous CaCC. Our data suggest thatBest1belongs to a group of genes upregulated by nerve injury and supports functional CaCC expression in injured sensory neurons.