Investigation Of The Roles Of Matriptase And Its Substrates In The Development Of Porcine Placenta Fold

Litter size is a key indicator of the reproductive properties of sows.It is affected by ovulation rate,attachment rate and placental efficiency.During 26 day gestation,after pig placenta trophoblast epithelium and endometrial epithelium adhered,the bilayer undergoes microscopic folding and forms placenta fold.The development of placenta fold affects placental efficiency directly.Many studies report that matriptase and its substrates play an important role in cell proliferation,migration,so this study intends to explore its role in the development of pig placenta fold,which may provide basis for revealing the mechanism of placental efficiency.In this study,we examined the expression pattern and activation state of matriptase and its downstream substrates in Yorkshire pigs on Days 12,15,18,26,50 and 95 of gestation by immunohistochemical technique and western blotting technique.The results are as follows:㈠Clone of two transcripts of pig ST14 geneST14(suppression of tumorigenicity 14)gene encodes matriptase,we cloned the two transcripts of pig ST14 gene by PCR and sequencing validation.㈡Investigation of the roles of matriptase and its substrates in the development of porcine placenta fold1.We tested the expression of matriptase and its downstream substrate MMP1 in the placenta fold during days 12,15,18 of gestation in Yorkshire by immunohistochemical technique.Results showed matriptase and MMP1 only expressed in placenta trophoblast.We also examined the expression of matriptase and MMP1 of Yorkshire pigs on Days 26,50 and 95 of gestation.Results displayed that the expression pattern of matriptase and MMP1 are the same : expressed in the trophoblast epithelium of pig placenta fold on day26 of gestation,expressed in the trophoblast epithelium of the side and bottom of placenta fold on day 50 and 95 of gestation.Further western blotting test results were found that matriptase and MMP1 are both activated in the placenta of day 50 and 95 of gestation.And maybe matriptase activates pro-MMP1 in the placenta trophoblast.2.We tested the expression of matriptase and its downstream substrate PAR2 andCCND1 in the placenta fold during days 12,15,18 of gestation in Yorkshire by immunohistochemical technique.Results showed that the expression pattern of PAR2 and CCND1 are the same with matriptase.Subsequently,the results of western blotting showed that PAR2 expresssed and were activated in the chorionic tissues on day 26,50,95 of gestation.All of the results verify matriptase perhaps participates to activate PAR2/TGF-β/CCND1 pathway.3.We examined the expression of basement membrane IV collogen and laminin during days 26,50,95 of gestation in Yorkshire by immunohistochemical technique,results revealed that the expression pattern of IV collogen and laminin are completely opposite with matriptase: expressed in the trophoblast on top of the pig placenta fold,not expressed in the trophoblast on bottom of the pig placenta fold.It explained that maybe matriptase takes part in the degradation of basement membrane in pig placenta trophoblast.