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This Article Full Text Full Text (PDF) All Versions of this Article: 295/4/L688    most recent 00504.2007v1 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 ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Chang, R. Articles by Nelin, L. D. PubMed PubMed Citation Articles by Chang, R. Articles by Nelin, L. D.

Cytokine-induced arginase activity in pulmonary endothelial cells is dependent on Src family tyrosine kinase activity

¹Centers for Perinatal Research and Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The Ohio State University, Columbus, Ohio; ²Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; and ³Vascular Physiology Group, Departments of Pediatrics and Cell Biology and Physiology; University of New Mexico, Albuquerque, New Mexico

Submitted 7 December 2007 ; accepted in final form 8 July 2008

We hypothesized that the Src family tyrosine kinases (STKs) are involved in the upregulation of arginase and inducible nitric oxide synthase (iNOS) expression in response to inflammatory stimuli in pulmonary endothelial cells. Treatment of bovine pulmonary arterial endothelial cells (bPAEC) with lipopolysaccharide and tumor necrosis factor- (L/T) resulted in increased urea and nitric oxide (NO) production, and this increase in urea and NO production was inhibited by the STK inhibitor PP1 (10 µM). The STK inhibitors PP2 (10 µM) and herbimycin A (10 µM) also prevented the L/T-induced expression of both arginase II and iNOS mRNA in bPAEC. Together, the data demonstrate a central role of STK in the upregulation of both arginase II and iNOS in bPAEC in response to L/T treatment. To identify the specific kinase(s) required for the induction of urea and NO production, we studied human pulmonary microvascular endothelial cells (hPMVEC) so that short interfering RNA (siRNA) techniques could be employed. We found that hPMVEC express Fyn, Yes, c-Src, Lyn, and Blk and that the protein expression of Fyn, Yes, c-Src, and Lyn could be inhibited with specific siRNA. The siRNA targeting Fyn prevented the cytokine-induced increase in urea and NO production, whereas siRNAs specifically targeting Yes, c-Src, and Lyn had no appreciable effect on cytokine-induced urea and NO production. These findings support our hypothesis that inflammatory stimuli lead to increased urea and NO production through a STK-mediated pathway. Furthermore, these results indicate that the STK Fyn plays a critical role in this process.

inducible nitric oxide synthase; L-arginine; lipopolysaccharide; lung injury