Equinatoxin II : how a cationic pore-forming sea anemone toxin drives nodal swelling of myelinated nerve fibers

Benoit, Evelyne (avtor), Frangež, Robert (avtor), Ouanounou, Gilles (avtor), Meunier, Frédéric A. (avtor), Šuput, Dušan (avtor), Molgó, Jordi (avtor)

This study was performed to elucidate the mechanism underpinning the nodal swelling induced by equinatoxin II (EqtII), a cation-selective pore-forming toxin derived from the sea anemone Actinia equina. Experiments were conducted using frog myelinated nerve fibers as a model system. Application of EqtII led to an approximately two-fold increase in the nodal volume of myelinated axons, but only when extracellular Ca2+ was present. Replacing extracellular Cl− with isethionate had no measurable effect on this response, whereas substitution of NaCl with either sucrose or LiCl, an established Na+/Ca2+ exchanger (NCX) inhibitor, abolished the swelling. The persistence of the effect in the presence of tetrodotoxin indicates that voltage-gated Na+ channels are not involved in the underlying mechanism. Our data suggest that Ca2+ influx through EqtII-induced membrane pores raises intracellular Ca2+ levels, thereby stimulating the NCX in its forward-operating mode. This process promotes Ca2+ extrusion in exchange for Na+ entry. The resulting accumulation of intracellular Na+ increases osmotic pressure within the axon, leading to water influx and nodal swelling.

• Jezik: Angleški jezik
• Ključne besede: axonal swelling, cationic pore-forming peptide, confocal laser scanning microscopy, equinatoxin II, ionic mechanisms, myelinated nerve fiber
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: VF - Veterinarska fakulteta ; MF - Medicinska fakulteta
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: 17 str.
• Številčenje: Vol. 24, iss. 5, art. 187
• PID: 20.500.12556/RUL-182933
• UDK: 615.9:577.15:616.8
• ISSN pri članku: 1660-3397
• DOI: 10.3390/md24050187
• COBISS.SI-ID: 279259907
• Datum objave v RUL: 29.05.2026

Gradivo je del revije

• Naslov: Marine drugs
• Skrajšan naslov: Mar. drugs
• Založnik: MDPI
• ISSN: 1660-3397
• COBISS.SI-ID: 23578841

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: otekanje aksonov, kationski peptid, ki tvori pore, konfokalna laserska vrstična mikroskopija, ekvinatoksin II, ionski mehanizmi, mielinizirano živčno vlakno