Effects Of Diallyl Trisulfide On Reproductive Performance And Placental Vascular Development In Pregnant Obese Mice

The placenta is the only organ connected between the mother and the fetus during pregnancy in mammals.Normal development of placenta is the basis of maintaining healthy fetal growth.Our previous study found that sows with higher backfat thickness at the end of gestation induces lipotoxic placental environment,inhibits placental angiogenesis and is associated with increasing the number of IUGR offspring.Furthermore,it increases perinatal insulin resistance and reduces feed intake of sows and weaning weight of piglets during lactation.Hydrogen sulfide?H₂S?is an ubiquitous second messenger for for cellular signal transduction,contributing to many physiological and pathological processes.For example,H₂S participates in the regulation of blood vessel development and relaxation,anti-inflammatory,anti-oxidation,and inhibition insulin secretion.However,whether H₂S can be used a nutritional regulation scheme to promote placental angiogenesis,alleviate inflammation and insulin resistance,and thus improve the reproductive performance of sows has not been studied thoroughly.In this study,mice models were as research subjects,and two experiments were carried out with the aim of this project.In experiment 1,40 female Kunming mice with normal body weight at 12 weeks of age were selected.After mating with normal male mice,pregnant maternal mice were randomly divided into two groups,namely the control group?n=13?and the experimental group?n=14?.During pregnancy,the experimental group was fed with diallyl trisulfide?DATS?,a donor of H₂S,at a dose of 1.5 mg/d;the control group was given an equal amount of PBS.All mice was slaughtered at 18.5 days of gestation,and maternal gestational weight,live litter,fetal weight,placental weight,and placental efficiency were measured.In experiment 2,60 female 8-week-old C57BL/6J mice were selected and divided into a control group?n=15?and a high-fat diet group?n=45?.Feeding 10 weeks,after successful mating with normal male mice,the pregnant maternal mice was divided into three groups,respectively.Group1,control group,normal maternal mice was fed normal diet and gavage with PBS?n=9?during pregnancy.Group 2,negative control group,obese maternal mice were fed a high-fat diet and gavage with PBS?n=8?during pregnancy.Group 3,experimental group,obese maternal mice were fed a high-fat diet and gavage DATS?n=10?during pregnancy.The data of body weight and feed intake of mice during pregnancy was collected.All mice were slaughtered at 18.5 days of gestation,maternal serum,inguinal fat,placenta and fetus were collected.The number of litters,live births,fetal weight,placental efficiency and coefficient of variation in litters were measured.H₂S levels of the serum and placental tissue were measured.The expression of m RNA related to the development of the placental blood vessels,the indexes related to the placental inflammation and oxidative stress,and the maternal serum insulin and glucose levels were measured.1. The results of Experiment 1 showed that feeding DATS during normal pregnancy mice,the number of born alive,fetal weight,placental weight and placental efficiency were not significantly different from those of the control group?P>0.05?.2. The main research contents and results of Experiment 2 are as follows:2.1 The feed intake,weight and reproductive performance of mice during pregnancy:the feed intake of pregnant mice in the control group was significantly higher than that in the negative control group and the experimental group?P<0.05?,but there was no significant difference in the total energy intake between the three groups?P>0.05?.The weight gain during pregnancy in the control group was significantly higher than that in the other two groups?P<0.05?.There were no significant differences in the placenta weight,embryo absorption rate,placental efficiency,and intra-fetal variation coefficient among the three groups?P>0.05?.However,the number of litters of the experimental group?8.50±1.27?was significantly higher than that of the negative control group?7.00±1.20??P<0.05?,and there was no significant difference in live litter size between the experimental group?6.75±1.16?and the negative control group?6.75±1.16?and the control group?7.0±1.50??P>0.05?.2.2. Serum and placental tissues H₂S content of pregnant mice:the content of H₂S in serum of the experimental group?47.10±7.71?M?was significantly higher than the control group?29.17±8.39?M?and the negative control group?14.06±4.62?M??P<0.05?.The content of H₂S in maternal placental tissue was significantly higher in the experimental group?19.86±4.17nmol/mg?and the control group?20.26±3.77nmol/mg?than in the negative control group?15.55±2.39nmol/mg??P<0.05?.2.3 Relative indexes of placenta angiogenesis:the blood vessel density of the placenta labyrinth zone of the experimental group and the control group was significantly higher than the negative control group?P<0.05?.The m RNA expression of CD31 of placenta vascular endothelial cell marker factor was also significantly lower in the negative control group than other two groups?P<0.05?.However,the m RNA expression levels of HIF-1?and i-NOS were significantly higher than the experimental group and the control group?P<0.05?.2.4 Placenta tissues inflammation and oxidative stress indicators:compared with the negative control group,the m RNA expression of placental inflammatory factors TNF-?,IL-1?,IL-6,IL-8 and MCP-1 was significantly reduced in the experimental group?P<0.05?.Although there was no significant change in the total antioxidant capacity of the maternal mice serum among the three groups?P>0.05?,but the total antioxidant capacity of the placenta tissue of the experimental group was significantly higher than the control group and the negative control group?P<0.05?.The total antioxidant capacity of fetal homogenate was significantly lower in the control group than other two groups?P<0.05?.2.5 Blood biochemical indexes of pregnant mice:the content of low-density lipoprotein cholesterolin in the serum of the experimental group?0.10±0.05mmol/L?was significantly lower in the control group?0.14±0.03mmol/L?and the negative control group?0.18±0.04mmol/L??P<0.05?.There was no significant difference in maternal serum glucose level among the experimental group?4.71±0.71m M?,the negative control group?5.33±1.05m M?and the control group?4.13±1.14??P>0.05?.However,the maternal serum insulin level of the experimental group?5.78±0.28ml U/L?was significantly lower than the control group?6.27±0.41ml U/L?and the negative control group?6.54±0.34ml U/L??P<0.05?.While the homeostatic model index?HOMA-IR?of the negative control group was significantly higher than the experimental group and the control group?P<0.05?.In summary,the conclusions of this study are as follows:after feeding DATS to obese maternal mice during pregnancy,the total number of litter and the number of born alive were increased.The reason may be related to the increase of angiogenesis of placenta by the exogenous addition of DATS.Moreover,DATS also reduced the expression of placental proinflammatory cytokines,improved lipid metabolism in obese maternal mice during pregnancy,and thus alleviated the perinatal insulin resistance of maternal mice.