Abstract
Hemolytic uremic syndrome (HUS) is a severe renal disease that is often preceded by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC). The exact mechanism of Stx-mediated inflammation on human glomerular microvascular endothelial cells (HGMVECs) during HUS is still not well understood. In this study, we investigated the effect of Stx1 on the gene expression of proteins involved in leucocyte-mediated and complement-mediated inflammation. Our results showed that Stx1 enhances the mRNA and protein expression of heparan sulfate proteoglycan (HSPG) syndecan-4 in HGMVECs pre-stimulated with tumor necrosis factor α (TNFα). CD44 was upregulated on mRNA but not on protein level; no effect on the mRNA expression of other tested HSPGs glypican-1 and betaglycan was observed. Furthermore, Stx1 upregulated the mRNA, cell surface expression, and supernatant levels of the intercellular adhesion molecule-1 (ICAM-1) in HGMVECs. Interestingly, no effect on the protein levels of alternative pathway (AP) components was observed, although C3 mRNA was upregulated. All observed effects were much stronger in HGMVECs than in human umbilical endothelial cells (HUVECs), a common model cell type used in endothelial studies. Our results provide new insights into the role of Stx1 in the pathogenesis of HUS. Possibilities to target the overexpression of syndecan-4 and ICAM-1 for STEC-HUS therapy should be investigated in future studies.
Highlights
Hemolytic uremic syndrome (HUS) is a severe renal illness that is characterized by hemolytic anemia, thrombocytopenia, and acute renal failure [1,2]
As the endothelium of the kidney is mainly involved in the pathogenesis of HUS, differences between these endothelial cell types could be of high importance for the understanding of the disease, and, to date, not many studies have been done on Shiga toxin (Stx) with primary human glomerular microvascular endothelial cells (HGMVECs)
heparan sulfate proteoglycan (HSPG) expressed in human tissues, but here, we focused on the HSPGs CD44, syndecan-4, glypican-1, and betaglycan because these are known to be expressed on the glomerular endothelial surface and may be relevant in HUS [15]
Summary
Hemolytic uremic syndrome (HUS) is a severe renal illness that is characterized by hemolytic anemia, thrombocytopenia, and acute renal failure [1,2]. A high leucocyte blood count in the acute phase of the disease is related to a prognosis of a worse outcome [13] Both Stx and Stx induce leucocyte adhesion to the surface of primary HGMVECs, a cell type damaged in HUS. This process is partly abolished by heparinase treatment, indicating an important role for heparan sulfate proteoglycans (HSPGs) in Stx-mediated inflammation [14]. HUVECs. As the endothelium of the kidney is mainly involved in the pathogenesis of HUS, differences between these endothelial cell types could be of high importance for the understanding of the disease, and, to date, not many studies have been done on Stx with primary HGMVECs. There are numerous different. C3, CFH, complement factor I (CFI) and membrane cofactor protein (MCP)/CD46, as altered expression of these genes may lead to local inflammation-mediated damage in glomeruli
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
