Study On The Influence Of Related Roles In Placental Trophablast By Toxoplasma Prevalent In China

Toxoplasma gondii is an obligate intracellular protozoan parasite with a high pathogenic potential. Toxoplasmosis affects such as mammals and birds, and humans as well of which a wide range of hosts.Toxoplasmosis, transmitted to human commonly through ingestion of raw or undercooked meat, or of the oocyst expelled by pets. For the course of its zoonotic nature, this disease has endangered public health worldwide. Congenital toxoplasmosis may result in abortion, premature birth, congenital malformation,severe mental retardation,dead fetus and neurologic damage in the offspring. Placenta damage is considered as the key event in this disease. Objective:To investigate oxidative and apoptosis level in Placental Trophablast in vivo by Toxoplasma Infection and to clarify the mechanisms of congenital toxoplasmosis for potential usage as therapeutic regimen for the treatment of T.Gondii-related diseases. Methods:ICR pregnant mice were divided into two groups:normal control group and T. gondii infection group.On the 8th day of pregnancy, each pregnant mice in the T.gondii infection group was injected intraperitoneally with 200 tachyzoites and normal group received nothing.Each mice was sacrificed on the 12 th day、14th day、 16 th day of pregnancy,placentas were carefully separated and processed into cell suspension for Flow Cytometer analysis,portion preserved snap-frozen in liquid nitrogen. The concentration of MDA, GSH, 8-OHd G, SOD, Capase9,and the expression of the 6apoptosis and ROS in placenta homogenates were measured as the manufactures’ instructions. Results:(1)The WH-3 T.gondii tachyzoites mouse had Symptoms of infection after 14 th day,most died after 16 th day.(2)ELISA results showed that the placenta homogenates concentration of T-AOC、MDA and 8-OHd G increased along with an increase in the days of pregnancy compared with the experimental group and the normal control group,however the concentration of GSH decreased.For each group, the difference in the concentrations of T-AOC、MDA、8-OHd G and GSH from pregnant mice on the 12th、14th day of pregnancy was statistically significant.The concentrations of T-AOC increased from 0.315± 0.014mmol/gprot(12th day)、0.151± 0.029 mmol/gprot(14th day) in the normal control group to 0.402± 0.068mmol/gprot(12th day)、0.315± 0.042 mmol/gprot(14th day)(p<0.01)in the experimental group。 Severe oxidative stress also resulted in peroxidation of lipids and DNA, presenting with increased levels of MDA, 8-OHd G:The concentrations of MDA and 8-OHd G increased respectively from 2.52±0.42 u M/gprot(12th day)、2.57±0.44 u M/gprot(14th day) and 0.91±0.26 ug/gprot(12th day)、0.98±0.26ug/gprot(14th day)in the normal control group to 3.13±0.57 u M/gprot(12th day)、3.92±0.86 u M/gprot(14th day) and 1.12±0.17 ug/gprot(12th day)、2.65±0.45 ug/gprot(14th day)(p<0.05) in the experimental group;The concentrations of GSH decreased from 9.87±1.35 u M/gprot(12th day)、9.88±1.37 u M/gprot(14th day) in the normal control group to 8.7±1.33 u M/gprot(12th day)、6.3±1.2 u M/gprot(14th day)(p<0.01)in the experimental group。(3)Results of Flow Cytometer analysis showed that the expression of the apoptosis and ROS in placenta homogenates increased along with an increase in the days of pregnancy.(4)A marked decrease of ROS was observed in 0.5m M/L apocynin treatment group. The activation of caspase-9, caspase-8, and caspase-3 were also detected by colorimetrical method or Western blotting. The cleavage and the increased activity of caspase-9 and caspase-3, rather than caspase-8, were found in T.gondii infection group. Conclusion:Infection with WH-3 T.Gondii tachyzoites can break out the oxidative Stress and placental trophablast apoptosis during pregnant.Besides, ROS-mediated ER stress result in Placental trophoblast apoptosis.