S-9-2 Syndecan-4 deficiency impairs the fetal vessels in the placental labyrinth.
K. Ishiguro, T. Kojima Nagoya University, School of Medicine and Nagoya University, School of Health Sciences, Nagoya, Japan


@ Syndecan-4 (Ryudocan) is a transmembrane protein with heparan sulfate glycosaminoglycans.

@ In situ hybridization and immunohistochemical staining demonstrated that the expression of syndecan-4 in the microvasculature was restricted to the placental labyrinth and the kidneys of adult mice. We have generated syndecan-4 deficient [Synd4(-/-)] mice to investigate its biological functions. The area of degeneration of the fetal vessels in the placental labyrinth at 17.5 gestational days was more diffuse and larger in the placentas of Synd4(-/-) embryos than wild-type [Synd4(+/+)] controls. Calcium deposition at the degenerated vessels was also more extensive and severer in the placentas of Synd4(-/-) embryos. When lipopolysaccharide or k-carrageenan was injected intraperitoneally into pregnant Synd4(+/-) mice mated with Synd4(+/-) males, intrauterine growth of Synd4(-/-) embryos was affected more severely than that of Synd4(+/+) controls. Thus, syndecan-4 deficiency impaired the fetal vessels in the placenta, especially under procoagulant stress, likely due to a deficit in the anticoagulation mechanism.

@ Among a large number of core proteins of heparan sulfate proteoglycans, it is the first report demonstrating that a defect of a single core protein caused an increased blood coagulation in a specific site.