Effect of Vibrio parahaemolyticus haemolysin on human erythrocytes

• Published in: Cellular microbiology Vol. 6; no. 4; pp. 391 - 400
• Main Authors: Lang, Philipp A., Kaiser, Stephanie, Myssina, Swetlana, Birka, Christina, Weinstock, Christof, Northoff, Hinnak, Wieder, Thomas, Lang, Florian, Huber, Stephan M.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.04.2004
• Subjects: Annexins - metabolism; Apoptosis; Calcium - chemistry; Calcium - metabolism; Cations - metabolism; Cell Membrane Permeability - drug effects; Cell Size - drug effects; Clotrimazole - pharmacology; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Erythrocytes - cytology; Erythrocytes - drug effects; Erythrocytes - metabolism; Erythrocytes - physiology; Flow Cytometry; Hemolysin Proteins - toxicity; Hemolysis; Humans; In Vitro Techniques; Ionomycin - pharmacology; Patch-Clamp Techniques; Potassium - metabolism; Potassium Channels - physiology; Vibrio parahaemolyticus
• ISSN: 1462-5814; 1462-5822
• DOI: 10.1111/j.1462-5822.2004.00369.x

Summary Haemolysin Kanagawa, a toxin from Vibrio parahaemolyticus, is known to trigger haemolysis. Flux studies indicated that haemolysin forms a cation channel. In the present study, channel properties were elucidated by patch clamp and functional significance of ion fluxes by fluorescence‐activated cell sorting (FACS) analysis. Treatment of human erythrocytes with 1 U ml−1 haemolysin within minutes induces a non‐selective cation permeability. Moreover, haemolysin activates clotrimazole‐sensitive K+ channels, pointing to stimulation of Ca2+‐sensitive Gardos channels. Haemolysin (1 U ml−1) leads within 5 min to slight cell shrinkage, which is reversed in Ca2+‐free saline. Erythrocytes treated with haemolysin (0.1 U ml−1) do not undergo significant haemolysis within the first 60 min. Replacement of extracellular Na+ with NMDG+ leads to slight cell shrinkage, which is potentiated by 0.1 U ml−1 haemolysin. According to annexin binding, treatment of erythrocytes with 0.1 U ml−1 haemolysin leads within 30 min to breakdown of phosphatidylserine asymmetry of the cell membrane, a typical feature of erythrocyte apoptosis. The annexin binding is significantly blunted at increased extracellular K+ concentrations and by K+ channel blocker clotrimazole. In conclusion, haemolysin Kanagawa induces cation permeability and activates endogenous Gardos K+ channels. Consequences include breakdown of phosphatidylserine asymmetry, which depends at least partially on cellular loss of K+.