Reactive oxygen species regulate the activity of matrix metalloproteinases in the placenta from normal and diabetic rats

PUSTOVRH C; JAWERBAUM A; LÓPEZ COSTA JJ; CAPOBIANCO E; WHITE V; HIGA R; GONZÁLEZ E

Buenos Aires

Congreso; XII Biennial Meeting of the Society for Free Radical Research International; 2004

Society for Free Radical Research

Matrix metalloproteinases (MMPs) are enzymes that degrade components of the extracellular matrix, and their expression is associated with normal tissue remodeling and growing processes. Abnormal MMPs levels contribute to pathological conditions  and are associated with non-controlled matrix degradation, incorrect cellular migration and proliferation in different tissues, including the placenta. Reactive oxygen species play a regulatory role on the inactive MMP proenzyme leading to the generation of the active form. In the diabetic pathology there are abnormal levels of MMPs, enhanced levels of ROS and alterations in the antioxidant defense mechanisms in different tissues. The aims of the present work are: -To evaluate MMP2 and MMP9 activities in the placenta of normal and diabetic rats; -To determine the influence of reactive oxygen species (ROS) on MMP2 and MMP9 enzymatic activity in the placenta from control and diabetic rats. METHODS: Rats were made diabetic by the administration of streptozotocin (100mg/Kg) to neonates, a method that leads in the adult to a stable and chronic non-insulin dependent diabetic model. Control and diabetic rats were mated with control males, and the placetal tissue (decidua and fetal side) was evaluated on day 14 of pregnancy for MMP2 and MMP9 activity  (by zymography analysis) . To evaluate the effect of ROS on MMP2 and MMP9 activity, placental tissue were incubated 1 h  in the presence or absence of ROS and antioxidants. RESULTS: In the decidual tissue of diabetic rats (DD) there are increased MMP2 (35%) and MMP 9 (40%) activity when compared to controls (DC) (p<0.005). MMP9 activity is present in the placental fetal side from control rats (FC), and its levels increase in diabetic (FD) (30%; p<0.05). MMP2 activity is absent in FC , but is present in FD. ROS additions (H2O2 50mM) increases MMP9 activity in DC (40%) and DD (30%) (p<0.05) while SOD (superoxide dismutase 1000U/ml) additions reduce MMP9 activity in these tissues ( 20% in CD and 35% in DD; p<0.05). Although MMP2 activity does not change in the presence or absence of H2O2 in DC, hydrogen peroxide enhances MMP2  activity in DD (40% p<0.05), and SOD reduces its activity (30%p<0.05). Differently, in the fetal side, neither MMP9 or MMP2 activity are modified in the presence of  H2O2. CONCLUSIONS: MMP2 and MMP9 are differently regulated in the fetal and maternal placental sides. In the decidua, ROS modulate MMP s activity, while the fetal side seem to be rather  resistant to those changes. Placental tissues from diabetic animals, Both in the maternal and fetal sides show higher MMP s activity than control, alterations that may be related to an increased oxidative stress, leading to an  abnormal remodeling processe and affecting the placental development in diabetes.