Dysfunction, oxidative stress markers and cytokine expression in the placentae of mice experimentally infected with Neospora caninum

Neosporosis is the major cause of abortion and reproductive failures in cattle, leading to important economic losses. In this study, we evaluated the impact of Neospora caninum infection on oxidative stress (OS) markers and local cytokine mRNA expression at the placenta, as well as its effect on the progesterone (P 4 ) serum levels and systemic cytokine profile in a pregnant mouse model. Infected pregnant mice (NC-1 group) showed increased percentages of foetal losses and IFN-γ serum levels, decreased serum progesterone, increased mRNA expression levels of both Th1 (IFN-γ and TNF-α) and Th2 (IL-4) cytokines and inhibited expression of TGF-β1 (Treg) compare to control dams (CONTROL group). In addition, lipid peroxidation and ROS were increased, whereas the antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) showed impairment in their activities in the placentae from infected mice compared to control mice. These findings demonstrate that multiple factors, including OS, are involved in foetal losses associated with N. caninum infection in mice, thus OS contribution to the placental physiopathology of neosporosis in other hosts must not be ruled out.