Synthesis of Anticoagulantly Active Heparan Sulfate Proteoglycans by Glomerular Epithelial Cells Involves Multiple 3-O-Sulfotransferase Isoforms and a Limiting Precursor Pool
| Autor: | Armin Helisch, Béatrice Birmelé, Nicholas W. Shworak, Sassan Hajmohammadi, Eric Girardin, Ariane De Agostini |
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| Rok vydání: | 2005 |
| Předmět: |
Male
Gene isoform Sulfotransferase Cell type Kidney Glomerulus RNA Messenger/metabolism Anticoagulants/metabolism ddc:616.07 Epithelial Cells/enzymology/metabolism Biology Biochemistry Isozyme Rats Sprague-Dawley Mice chemistry.chemical_compound medicine Animals RNA Messenger Isoenzymes/metabolism Molecular Biology Cells Cultured Regulation of gene expression ddc:618 Sulfotransferases/genetics/metabolism Kidney Glomerulus/cytology/enzymology Glomerular basement membrane fungi Anticoagulants Epithelial Cells Cell Biology Heparan sulfate In vitro Rats Isoenzymes medicine.anatomical_structure Gene Expression Regulation chemistry Heparan Sulfate Proteoglycans/biosynthesis Sulfotransferases Gene Deletion Heparan Sulfate Proteoglycans |
| Zdroj: | Journal of Biological Chemistry, Vol. 280, No 45 (2005) pp. 38059-38070 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m507997200 |
| Popis: | Endothelial and other select cell types synthesize a subpopulation of heparan sulfate (HS) proteoglycans (HSPGs), anticoagulant HSPGs (aHSPGs) that bear aHS-HS chains with the cognate 3-O-sulfated pentasaccharide motif that can bind and activate anti-thrombin (AT). Endothelial cells regulate aHSPG production by limiting levels of HS 3-O-sulfotransferase-1 (3-OST-1), which modifies a non-limiting pool of aHS-precursors. By probing kidney cryosections with (125)I-AT and fluorescently tagged AT we found that the glomerular basement membrane contains aHSPGs, with the staining pattern implicating synthesis by glomerular epithelial cells (GECs). Indeed, cultured GECs synthesized aHS with high AT affinity that was comparable with the endothelial product. Disaccharide analyses of human GEC (hGEC) HS in conjunction with transcript analyses revealed that hGECs express predominantly 3-OST-1 and 3-OST-3(A). aHS production has not been previously examined in cells expressing multiple 3-OST isoforms. This unusual situation appears to involve novel mechanisms to regulate aHS production, as HS structural analyses suggest hGECs exhibit excess levels of 3-OST-1 and an extremely limiting pool of aHS-precursor. A limiting aHS-precursor pool may serve to minimize aHS synthesis by non-3-OST-1 isoforms. Indeed, we show that high in vitro levels of 3-OST-3(A) can efficiently generate aHS. Non-3-OST-1 isoforms can generate aHS in vivo, as the probing of kidney sections from 3-OST-1-deficient mice revealed GEC synthesis of aHSPGs. Surprisingly, Hs3st1(-/-) kidney only expresses 3-OST isoforms having a low specificity for aHS synthesis. Thus, our analyses reveal a cell type that expresses multiple 3-OST isoforms and produces minimal amounts of aHS-precursor. In part, this mechanism should prevent aHS overproduction by non-3-OST-1 isoforms. Such a role may be essential, as 3-OST isoforms that have a low specificity for aHS synthesis can generate substantial levels of aHSPGs in vivo. |
| Databáze: | OpenAIRE |
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