Increased expression of heparan sulfate proteoglycan on the cultured renal epithelial cells during oxalate exposure.
ABSTRACT We have previously 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 mechanism of the increased syndecan expression still remains unclear, HS/syndecan is thought to have some important roles in CaOx crystal formation. The present study examined the role of HS during oxalate exposure by using a newly developed cell line (KIC-synd-1) that expresses human heparan sulfate proteoglycan (syndecan-1). Quantitative competitive (QC)-RT-PCR was used to examine change of syndecan-1 mRNA expression in KIC-synd-1 cells. Production of syndecan-1 core protein and glycosaminoglycans (GAGs) were also confirmed by Western blot, immunohistochemistry and HPLC, respectively. Wild type Mardin-Darby canine kidney (MDCK) cells were also examined in the same manner. The stable expression of syndecan-1 gene and production of both core protein and HS chains were confirmed in the newly developed KIC-synd-1 cell line. Increased syndecan-1 mRNA expression and production of core proteins were confirmed in KIC-synd-1 cells during oxalate exposure. MTT assay revealed that the cell viability decreased significantly in the MDCK cells after 1 mM oxalate exposure (p<0.05). On the other hand, there was no significant difference in the oxalate exposed KIC-synd-1 cells. However, the cell viability in KIC-synd-1 cells pretreated with heparitinase digestion decreased significantly before oxalate exposure (p<0.05). The present data suggests that both exogenous and endogenous HS exerts protective effect against oxalate-induced cell injuries. Previous studies in our laboratory have indicated that hyperoxaluria and deposition of CaOx crystals resulted in renal tubular cellular injury inducing the synthesis of HSPG to protect and repair the damaged epithelial cell surface. The present data offers strong support for this hypothesis. Finally, HS could be potent inhibitor of CaOx nephrolithiasis and the absence of this substance on the tubular surface may increase the risk of CaOx crystal formation and retention.
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ABSTRACT: The early use of fresh frozen plasma as a resuscitative agent after hemorrhagic shock has been associated with improved survival, but the mechanism of protection is unknown. Hemorrhagic shock causes endothelial cell dysfunction and we hypothesized that fresh frozen plasma would restore endothelial integrity and reduce syndecan-1 shedding after hemorrhagic shock. A prospective, observational study in severely injured patients in hemorrhagic shock demonstrated significantly elevated levels of syndecan-1 (554±93 ng/ml) after injury, which decreased with resuscitation (187±36 ng/ml) but was elevated compared to normal donors (27±1 ng/ml). Three pro-inflammatory cytokines, interferon-γ, fractalkine, and interleukin-1β, negatively correlated while one anti-inflammatory cytokine, IL-10, positively correlated with shed syndecan-1. These cytokines all play an important role in maintaining endothelial integrity. An in vitro model of endothelial injury then specifically examined endothelial permeability after treatment with fresh frozen plasma orlactated Ringers. Shock or endothelial injury disrupted junctional integrity and increased permeability, which was improved with fresh frozen plasma, but not lactated Ringers. Changes in endothelial cell permeability correlated with syndecan-1 shedding. These data suggest that plasma based resuscitation preserved endothelial syndecan-1 and maintained endothelial integrity, and may help to explain the protective effects of fresh frozen plasma after hemorrhagic shock.PLoS ONE 01/2011; 6(8):e23530. · 3.53 Impact Factor