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Evaluation of cell damage and modulation of cytokines TNF-α, IL-6 and IL-10 in macrophages exposed to PpIX-mediated photodynamic therapy

Avaliação do dano celular e da modulação das citocinas TNF-α, IL-6 e IL-10 em macrófagos expostos à terapia fotodinâmica mediada pela PpIX

Abstract

Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (MΦ), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated MΦ cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal MΦ from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-α, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 10–30%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF-α and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in MΦ.

Keywords:
photodynamic therapy; macrophage; DNA damage; cytokines; oxidative stress

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