학술논문

Novel synthetic sulfoglycolipid IG20 facilitates exocytosis in chromaffin cells through the regulation of sodium channels
Document Type
Academic Journal
Source
Journal of Neurochemistry. Dec 01, 2015 135(5):880-896
Subject
Language
English
ISSN
0022-3042
Abstract
ABSTRACT: In search of druggable synthetic lipids that function as potential modulators of synaptic transmission and plasticity, we synthesized sulfoglycolipid IG20, which stimulates neuritic outgrowth. Here, we have explored its effects on ion channels and exocytosis in bovine chromaffin cells. IG20 augmented the rate of basal catecholamine release. Such effect did not depend on Ca mobilization from intracellular stores; rather, IG20-elicited secretion entirely dependent on Ca entry through L-subtype voltage-activated Ca channels. Those channels were recruited by cell depolarization mediated by IG20 likely through its ability to enhance the recruitment of Na channels at more hyperpolarizing potentials. Confocal imaging with fluorescent derivative IG20-NBD revealed its rapid incorporation and confinement into the plasmalemma, supporting the idea that IG20 effects are exerted through a plasmalemmal-delimited mechanism. Thus, synthetic IG20 seems to mimic several physiological effects of endogenous lipids such as regulation of ion channels, Ca signaling, and exocytosis. Therefore, sulfoglycolipid IG20 may become a pharmacological tool for investigating the role of the lipid environment on neuronal excitability, ion channels, neurotransmitter release, synaptic efficacy, and neuronal plasticity. It may also inspire the synthesis of druggable sulfoglycolipids aimed at increasing synaptic plasticity and efficacy in neurodegenerative diseases and traumatic brain–spinal cord injury. : (Figure is included in full-text article.) : The novel synthetic sulfoglycolipid IG20 mimics several physiological effects of endogenous lipids such as regulation of ion channels, Ca signaling, and exocytosis. This profile may eventually drive enhanced synaptic plasticity and efficacy.(Figure is included in full-text article.)