IFN-gamma alters the human sperm membrane permeability to Ca(2+).
Inflammation in the male genitourinary tract has been associated with the release of pro-inflammatory cytokines such as interferon-gamma (IFN-γ) and elevated reactive oxygen species, which affects spermatozoa capacitation, motility, and the acrosome reaction, along with functions regulated by the concentration of cytoplasmic Ca(2+) ([Ca(2+)]cyto). Though Ca(2+) signaling is of particular significance in sperm, the effect of IFN-γ intracellular calcium on these cells is still unknown. The present study evaluated the effect of IFN-γ on the [Ca(2+)]cyto and Ca(2+) permeability on human sperm. A cell suspension loaded with fura-2 was incubated with or without IFN-γ (from 0 to 2000 pg/ml) for 0, 30, 60, and 120 minutes, and the [Ca(2+)]cyto was measured. The permeability to Ca(2+) was evaluated by the change of the intracellular concentration following an extracellular Ca(2+) pulse. IFN-γ at low concentrations (≤ 500  pg/ml) did not affect the [Ca(2+)]cyto and Ca(2+) permeability of sperm. At a high concentration (2000  pg/ml), IFN-γ did not alter the [Ca(2+)](cyto), but significantly decreased the magnitude and velocity of Ca(2+) entry into the cell. This effect was dependent on incubation time and IFN-γ concentration. This alteration induced by IFN-γ was prevented by the simultaneous incubation of sperm with the antioxidant butylhydroxytoluene (BHT). In conclusion, in vitro, IFN-γ modifies Ca(2+) sperm membrane permeability, probably via lipid peroxidation. IFN-γ in high concentration, as observed in inflammation/infection, can affect [Ca(2+)](cyto) regulation and alter sperm fertilizing capacity.
Laboratorio de Reproducción y Desarrollo Animal, Departamento de Biología de Organismos, Universidad Simón Bolívar , Caracas , Venezuela and.
Gabriela
G
Carrasquel
María I
MI
Camejo
Fabian
F
Michelangeli
Marie Christine
MC
Ruiz
D000328:Adult; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000502:physiology*; D017136:Ion Transport; D008297:Male; D013094:Spermatozoa / Q000378:metabolism*; D055815:Young Adult
D002084:Butylated Hydroxytoluene; D007371:Interferon-gamma; D002118:Calcium