Interactive Dynamics of Cell Volume and Cell Death in Human Erythrocytes Exposed to alpha-Hemolysin from Escherichia coli.
Saffioti, N. A., Lauri, N., Cane, L., Gonzalez-Lebrero, R., Alleva, K., Mouro-Chanteloup, I., Ostuni, M. A., Herlax, V. and Schwarzbaum, P. J.
Laboratorio de Biosensores Avanzados, Instituto de Nanosistemas, Universidad Nacional de San Martin, San Martin, Buenos Aires 1650, Argentina.
Departamento de Quimica Biologica, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Junin 956, Buenos Aires 1113, Argentina.
Instituto de Quimica y Fisico-Quimica Biologicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquimica, Junin 956, Buenos Aires 1113, Argentina.
Instituto de Investigaciones Bioquimicas de La Plata (INIBIOLP) CCT-La Plata, CONICET, Facultad de Ciencias Medicas, Universidad Nacional de La Plata, 60 y 120, La Plata, Buenos Aires 1900, Argentina.
Universite de Paris and Universite des Antilles, INSERM, BIGR, F-75015 Paris, France.
alpha-hemolysin (HlyA) of E. coli binds irreversibly to human erythrocytes and induces cell swelling, ultimately leading to hemolysis. We characterized the mechanism involved in water transport induced by HlyA and analyzed how swelling and hemolysis might be coupled. Osmotic water permeability (Pf) was assessed by stopped-flow light scattering. Preincubation with HlyA strongly reduced Pf in control- and aquaporin 1-null red blood cells, although the relative Pf decrease was similar in both cell types. The dynamics of cell volume and hemolysis on RBCs was assessed by electrical impedance, light dispersion and hemoglobin release. Results show that HlyA induced erythrocyte swelling, which is enhanced by purinergic signaling, and is coupled to osmotic hemolysis. We propose a mathematical model of HlyA activity where the kinetics of cell volume and hemolysis in human erythrocytes depend on the flux of osmolytes across the membrane, and on the maximum volume that these cells can tolerate. Our results provide new insights for understanding signaling and cytotoxicity mediated by HlyA in erythrocytes.
International Journal of Molecular Sciences 23(2): en prensa (2022)