[Mycoplasma penetrans lipid-associated membrane proteins induce nuclear factor kappaB activation-mediated apoptosis in mouse macrophage].

To investigate the potential pathogenicity of Mycoplasma penetrans (M. penetrans) and the possible molecular mechanisms, we investigated whether M. penetrans lipid-associated membrane proteins (LAMPs) could induce mouse macrophages Raw264.7 apoptosis by activating nuclear factor kappaB (NF-kappaB). Apoptosis was detected in M. penetrans LAMPs-stimulated mouse macrophages by Annexin-V-FITC staining and DNA fragmentation analysis. We also analyzed the activation of NF-kappaB and the effects of pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappaB, on M. penetrans LAMPs-induced mouse macrophages apoptosis by indirect immunofluorescence and Western blotting. Our results suggested that M. penetrans LAMPs could induce mouse macrophages significant early- and late-stage apoptosis. Agarose gel electrophoresis of the DNA of LAMPs-challenged cells revealed that a ladder-like pattern of migration of DNA indicative of apoptosis. M. penetrans LAMPs could activate NF-kappaB in mouse macrophages. PDTC could partially inhibit the activation of NF-kappaB and thus inhibit M. penetrans LAMPs-induced mouse macrophages apoptosis. This study demonstrates that M. penetrans LAMPs may be an important etiological factor due to its ability to induce mouse macrophages apoptosis, which was probably mediated through the activation of NF-kappaB.