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Signaling Molecules Involved in IFN-γ-Inducible Nitric Oxide Synthase Expression in the Mouse Trophoblast


Estela Bevilacqua, Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524 – Butantã, 05508-900 São Paulo – SP, Brazil.


Problem  We have previously shown that trophoblast can generate nitric oxide (NO) and express inducible isoform of nitric oxide synthase (iNOS). Moreover, this production was changed by the presence of interferon-γ (IFN-γ) establishing a relationship between trophoblast inductive response and this proinflammatory cytokine.

Method of study  As the intracellular signal transduction pathway used by IFN-γ in target cells is the Janus kinase (JAK)-signal transducer and transcription activator (STAT), here we analyzed in the mouse trophoblast the effect of IFN-γ and staurosporine on mRNA and protein expressions of IFN-γ signaling molecules correlating them with iNOS expression.

Results  Interferon-γ induced iNOS expression and upregulated Jaks and Stat1, but not Stat2 transcriptions. The protein distribution matched the mRNA expression pattern. These effects were abrogated when IFN-γ receptor was blocked by staurosporine.

Conclusion  Due to the biological effects of NO-iNOS generated on induction of apoptosis and inflammatory responses, interaction between iNOS expression and IFN-γ-mediated signaling is very important for understanding the physiology of trophoblast at the maternal–fetal interface. Our data indicate IFN-γ acts specifically on trophoblast, regulating the expression of signaling molecules and is fundamental for iNOS expression.