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This Article Full Text Full Text (PDF) All Versions of this Article: 293/5/F1441    most recent 00088.2007v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Vesey, D. A. Articles by Johnson, D. W. Search for Related Content PubMed PubMed Citation Articles by Vesey, D. A. Articles by Johnson, D. W.

Proinflammatory and proliferative responses of human proximal tubule cells to PAR-2 activation

¹Centre for Kidney Disease Research, University of Queensland Department of Medicine, Princess Alexandra Hospital, Brisbane, ²School of Biomedical Sciences, University of Queensland, St. Lucia; and ³Department of Molecular and Cellular Pathology, University of Queensland, Royal Brisbane Hospital, Brisbane, Queensland, Australia

Submitted 20 February 2007 ; accepted in final form 13 August 2007

Despite the abundant expression of protease-activated receptor (PAR)-2 in the kidney, its relevance to renal physiology is not well understood. A role for this receptor in inflammation and cell proliferation has recently been suggested in nonrenal tissues. The aims of this study were to demonstrate that human proximal tubule cells (PTC) express functional PAR-2 and to investigate whether its activation can mediate proinflammatory and proliferative responses in these cells. Primary human PTC were cultured under serum-free conditions with or without the PAR-2-activating peptide SLIGKV-NH₂ (up to 800 µM), a control peptide, VKGILS-NH₂ (200 µM), or trypsin (0.01–100 nM). PAR-2 expression (RT-PCR), intracellular Ca²⁺ mobilization (fura-2 fluorimetry), DNA synthesis (thymidine incorporation), fibronectin production (ELISA, Western blotting), and monocyte chemotactic protein (MCP)-1 secretion (ELISA) were measured. Trypsinogen expression in kidney and PTC cultures was determined by immunohistochemistry and Western blotting. In the kidney PTC were the predominant cell type expressing PAR-2. SLIGKV-NH₂, but not VKGILS-NH₂, stimulated a rapid concentration-dependent mobilization of intracellular Ca²⁺ and ERK1/2 phosphorylation and, by 24 h, increases in DNA synthesis, fibronectin secretion, and MCP-1 secretion. These delayed responses appeared to be independent of ERK1/2. Trypsin produced similar rapid but not delayed responses. Trypsinogen was weakly expressed by PTC in the kidney and in culture. In summary, PTC are the main site of PAR-2 expression in the human kidney. In PTC cultures SLIGKV-NH₂ initiates proinflammatory and proliferative responses. Trypsinogen expressed within the kidney has the potential to contribute to PAR-2 activation in certain circumstances.

protease-activated receptor-2; fibronectin; monocyte chemotactic protein-1; DNA synthesis