Effects Of Progesterone On The Endometrium Of Goats Infected With E.coli

Endometritis is a common reproductive disease of postpartum dairy cows,often causing increase in infertility,decrease in milk yield,and huge economic loss.Progesterone,as a steroid hormone,can lead to the accumulation of cytokines in the uterine cavity,the inhibition of lymphocyte function in vitro and the formation of antibody in vivo,which has a certain impact on uterine immunity.In order to explore the mechanism effects of progesterone on goat endometrium infected with E.coli,in this study,we tested the physiological indexes of goats infected by E.coli,detected changes in the number of WBC in blood and uterine secretions,observed uterine endometrial tissue structural changes,and elevated the changes in mRNA expression levels of TLR4,IL-1,IL-6,IL-8,TNF-?,TGF-?,VEGF and EGFR in endometrial tissue,using adult hybrid goats as experimental animals,which received an intramuscular injection of progesterone.The following is the test method:12 hybrid goats,30?40 kg were randomLy divided into 4 groups:control group,E.coli group,progesterone group,and P4+E.coli group.In a 10-day animal experiment period,daily intramuscular progesterone injection of lmg/kg was administered to the progesterone group and the P4+E.coli group respectively at 9:00 am.On the third day,the E.coli group and the P4+E.coli group received uterine infusion of 5mL(109cfu/mL)E.coli;in the meantime,the control group and the progesterone group received uterine infusion of 5mL saline.Temperature(T),pulse(P)and respiration(R)were observed at pre-inoculation(0h),12th,24th,96th and 168th h post inoculation with a thermometer and a stethoscope.Meanwhile,the blood collected from the jugular vein was mixed in the anticoagulant tube to detect the number of WBC by fully automatic haemacytometer analyzer.At the 24th,96th and 168th h post inoculation,uterine discharge was collected on a glass slide with a sterilized cotton swab and stained with Diff Quick,after this,the number of WBC was examined under bio microscope.On the 1st,4th and 7th day post inoculation,the endometrial tissues were collected by hysteroscope;part of the tissue was used for histopathological observation,which was fixed in 10%neutral formalin solution;and part of the tissue to be used for gene expression testing,was placed in RNase-free cryopreservation tube after washing with PBS and drying with sterilized filter paper and cryopreserved in liquid nitrogen.The following are the results:(1)Compared with the control group,the body temperature of E.coli group and P4+ E.coli group increased significantly(p<0.01)at the 12th and 24th h after injection,compared with the E.coli group,the body temperature of P4+E.coli group decreased,and the difference was significant(p<0.05).The number of WBC in peripheral blood of E.coli group was significantly higher than that of control group at 12 h and 24 h after injection(p<0.01).Compared with E.coli group,P4+ E.coli the number of peripheral blood WBC was significantly lower in the test goats(p<0.05).The number of WBCs in the secretions of goats was significantly higher than that of the E.coli group and the P4+E.coli group compared with the control group.Compared with the E.coli group,the P4+E.coli group,the number of WBCs in the secretions was significantly reduced.(2)On the first day after inoculation,a large number of leukocyte infiltration,uterine mucosal injury,and capillary congestion were observed in the uterine tissue of the E.coli group.P4+ E.coli group showed a small amount of leukocyte infiltration in goat uterine tissue sections.On the fourth day after inoculation,a large number of white blood cells was still observed in the E.coli group,and no change was observed in the other groups.(3)The relative expression of TLR4,IL-6,TNF-?,IL-1? and IL-8 mRNA in goat endometrium of the E.coli group was significantly higher than that in control group(p<0.05).Compared with E.coli group,the relative expression of TLR4,IL-6 and IL-8 mRNA in goat endometrium of P4+E.coli group was significantly lower than that of E.coli group(p<0.05).On the 4th day the relative expression of TLR4 and TNF-? mRNA in goat endometrium was significantly lower than that in the E.coli group(p<0.01).(4)on day 1,the mRNA expression of TGF-? in goat endometrium of the E.coli group and P4+E.coli group was higher than that of the control group,but the difference was not significant(p>0.05).The relative expression of VEGF and EGFR mRNA in goat endometrium of the P4,E.coli and P4+E.coli group was decreased,the E.coli group was significantly different(p<0.05).Compared with the E.coli group,the relative expression of TGF-? mRNA in goat endometrium of P4+ E.coli group was lower,but the difference was not significant(p>0.05).The mRNA expression of the P4+E.coli group the of VEGF was significantly increased,but the difference was not significant(p>0.05).In conclusion:after goat uterine infection,T,P,R,peripheral blood and uterine secretions WBC increased,and acute infection occurred in goats.Progesterone can regulate the expression of TLR4,IL-6,TNF-?,IL-1? and IL-8 in the endometrium of goats after the infection with E.coli,and regulate the expression of TGF-?,VEGF and EGFR,suggesting that progesterone,through the regulation of inflammatory cytokines and expression of cell proliferation factors have a certain impact on the local immunity but has no apparent effect on the repair of the uterus.