Block of L-Type Ca²⁺ Current by Beauvericin, a Toxic Cyclopeptide, in the NG108-15 Neuronal Cell Line

Abstract

The effects of beauverficin, a cyclodepsipeptide compound, on ion currents in a mouse neuroblastoma and rat glioma hybrid cell line, NG108-15, were investigated with the aid of the whole-cell voltage-clamp technique. Beauvericin (0.3-100 microM) reversibly produced an inhibition of L-type voltage-dependent Ca2+ current (I(Ca,L)) in a concentration-dependent manner. Beauvericin caused no change in the overall shape of the current-voltage relationship of I(Ca,L). The IC(50) value of beauvericin-induced inhibition of I(Ca,L) was 4 microM. Neither gabapentin (30 microM) nor omega-conotoxin GVIA (3 microM) had effects on I(Ca,L). Beauvericin (30 microM) shifted the steady-state inactivation curve of I(Ca,L) to more negative membrane potentials by approximately -15 mV. The inhibitory effects of beauvericin on I(Ca,L) exhibited tonic and use-dependent characteristics. Beauvericin also suppressed I(Ca,L) evoked by repetitive action potential waveforms effectively. However, beauvericin (30 microM) had no effect on delayed rectifier K+ current in NG105-18 cells. Under current-clamp configuration, beauvericin reduced the firing frequency of action potentials. Therefore, this study indicates that beauvericin is a relatively specific inhibitor of L-type Ca2+ current in NG108-15 cells.

Dexmedetomidine, an α2-adrenergic agonist, inhibits neuronal delayed-rectifier potassium current and sodium current

“…In these experiments, cells were bathed in normal Tyrode's solution, and the waveforms of APs were digitally generated as voltage templates and replayed to evoke ion currents. 19 As shown in Figure 7, the amplitudes of I Na and I K(DR) in response to AP waveforms were reduced in the presence of DEX. For example, after application of 1 mM DEX, the peak amplitude of I Na elicited by the waveforms of APs was decreased by about 10%.…”

The synergistic inhibitory actions of oxcarbazepine on voltage-gated sodium and potassium currents in differentiated NG108-15 neuronal cells and model neurons

“…The NG108-15 cell line has been widely used as a neuron model in electrophysiology and pharmacology research (Meves et al, 1999, Tsai et al, 2006Wu et al, 2001Wu et al, , 2002. It is a hybrid cell line derived from the fusion of mouse neuroblastoma (N18TG-2, a subclone of mouse C1300 neuroblastoma cells) and rat glioma (C6BV-1, a subclone of rat C6 glioma).…”

Further data on the occurrence of Fusarium emerging mycotoxins enniatins (A, A1, B, B1), fusaproliferin and beauvericin in raw cereals commercialized in Morocco

“…BEA was shown to be a specific cholesterol acyltransferase inhibitor (Tomoda et al, 1992). BEA inhibited the L-type Ca 2þ current in the NG108-15 neuronal cell line and increased the intracellular calcium by increasing the formation of cation selective channels in lipid membrane (Kouri, Lemmens, & Lemmens-Gruber, 2003;Wu, Chen, Liu, & Chiang, 2002).…”