3 research outputs found
Matrix metalloproteinases in subjects with type 1 diabetes
<p>Abstract</p> <p>Background</p> <p>Nephropathy is serious complication of diabetes. We have previously shown that level of the proteoglycan syndecan-1 in blood is associated with ultrastructural kidney changes in young persons with type 1 diabetes. Dysregulation of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) may contribute to the development of nephropathy. The aim of this study was to investigate if the levels of MMPs in blood samples are potential markers of early nephropathy in type 1 diabetes.</p> <p>Methods</p> <p>Blood samples were collected from type 1 diabetes patients after 11 years of diabetes (n = 15) and healthy volunteers (n = 12) and stored at ÷80°C until measurement. Levels and activities of serum MMP-2, MMP-9, TIMP-1 and TIMP- 2 were analyzed and compared to those of control individuals using ELISA, SDS-PAGE gelatin zymography, and Western blot analysis.</p> <p>Results</p> <p>The serum levels of both MMP-9 and MMP-2 were significantly higher in subjects with type 1 diabetes, compared to controls (p = 0.016 and p = 0.008 respectively). Western blotting revealed no differences between the two groups in the levels of TIMP-1 or TIMP-2, respectively.</p> <p>Conclusion</p> <p>Our MMP analysis of serum from a limited number of patients with type 1 diabetes suggest that such analysis is potentially useful as markers in studies of people at risk of progression to chronic kidney disease.</p
Serglycin Is a Major Proteoglycan in Polarized Human Endothelial Cells and Is Implicated in the Secretion of the Chemokine GRO alpha/CXCL1
Proteoglycan (PG) expression was studied in primary human
umbilical vein endothelial cells (HUVEC). RT-PCR analyses
showed that the expression of the PG serglycin core protein was
much higher than that of the extracellular matrix PG decorin and
the cell surface PG syndecan-1. PG biosynthesis was further studied by biosynthetic [35S]sulfate labeling of polarized HUVEC. Interestingly, a major part of 35S-PGs was secreted to the apical medium. A large portion of these PGs was trypsin-resistant, a typical
feature of serglycin. The trypsin-resistant PGs were mainly of the
chondroitin/dermatan sulfate type but also contained a minor
heparan sulfate component. Secreted serglycin was identified by
immunoprecipitation as a PG with a core protein of ㅖ kDa.
Serglycin was furthermore shown to be present in perinuclear
regions and in two distinct types of vesicles throughout the cytoplasm using immunocytochemistry. To search for possible serglycin partner molecules, HUVEC were stained for the chemokine
growth-related oncogene α (GROα/CXCL1). Co-localization
with serglycin could be demonstrated, although not in all vesicles.
Serglycin did not show overt co-localization with tissue-type plasminogen activator-positive vesicles. When PG biosynthesis was
abrogated using benzyl-β-D-xyloside, serglycin secretion was decreased, and the number of vesicles with co-localized serglycin
and GROα was reduced. The level of GROα in the apical medium
was also reduced after xyloside treatment. Together, these findings indicate that serglycin is a major PG in human endothelial
cells, mainly secreted to the apical medium and implicated in
chemokine secretion