Role of Heparan Sulfate Proteoglycan (Syndecan-1) on the Renal Epithelial Cells During Calcium Oxalate Monohydrate Crystal Attachment

We have reported that heparan sulfate (HS)/heparan sulfate proteoglycan (HSPG, syndecan-1) expression significantly increased in the rat kidney during calcium oxalate (CaOx) nephrolithiasis. Although the exact role of syndecan still remains unclear, HS/syndecan-1 is thought to have some important role in the CaOx crystal formation. Mardin-Darby canine kidney (MDCK) cells are most commonly used in kidney stone research. It was reported that MDCK cells do not express syndecan-1. In the present study, we established a novel MDCK cell line (KIC-synd-1) that expressed the human syndecan-1 gene. In this cell line, we confirmed stable expression of both sndecan-1 gene and core protein. Immunohistochemical study revealed positive staining of syndecan-1 monoclonal antibody in the basolateral and cytosolic area of the KIC-synd-1 cells. We also investigated the composition of glycosaminoglycans (GAGs) side chains in MDCK cells and KICsynd-1 cells by using high-performance liquid chromatography (HPLC). Four types of HS chains were identified in both cells as follows; ΔdiHS-NS, ΔdiHS-6S, ΔdiHS-diS1, ΔdiHS-diS2. Increased production of ΔdiHS-NS and ΔdiHS-diS2 were shown in KIC-synd-1 cells compared with production in MDCK cells (p