Publications by authors named "Paul L Dudas"

Interleukin-23 (IL-23) is a key cytokine implicated in the pathogenesis of autoimmune disorders, including psoriasis and ulcerative colitis. Although targeted IL-23 antibody therapeutics are used clinically, there are no small-molecule therapeutics that selectively inhibit IL-23 signaling. To address this gap, we developed a high-throughput screening strategy employing an IL-23-responsive cell-based luciferase reporter gene assay as the primary screen, with cellular cytotoxicity and off-target counter screening assays to identify IL-23 pathway-specific inhibitors.

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Background: Recent studies have demonstrated that Th2 responses have the ability to antagonize Th17 responses. In mouse models of allergic asthma, blockade of Th2-effector cytokines results in elaboration of Th17 responses and associated increases in pulmonary neutrophilia. While these can be controlled by simultaneous blockade of Th17-associated effector cytokines, clinical trials of anti-IL-17/IL-17RA blocking therapies have demonstrated increased of risk of bacterial and fungal infections.

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IL-13 and IL-17A, produced mainly by Th2 and Th17 cells, respectively, have an influential role in asthma pathogenesis. We examined the role of IL-13 and IL-17A in mediating airway hyperresponsiveness (AHR), lung inflammation, and mucus metaplasia in a dual Th2/Th17 model of asthma. IL-13 and/or IL-17A were neutralized using mAbs.

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Background/aims: Interleukin-17A (IL-17A) is a T cell-derived inflammatory cytokine that is upregulated during renal allograft rejection. The present study sought to further describe the IL-17A-mediated proinflammatory/profibrotic activity of proximal tubule epithelium that may contribute to allograft rejection.

Methods: Immortalized (HK-2) and primary (HRPTEpiC) human proximal tubule epithelial cells were utilized for this study.

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Background: In rodent models of chronic renal disease bone morphogenetic protein-7 (BMP-7) has been shown to halt disease progression and promote recovery. Subsequent studies utilizing immortalized rodent renal cell lines showed that BMP-7 was renoprotective by antagonizing TGF-beta1-stimulated epithelial-to-mesenchymal transition (EMT). The present study sought to determine if BMP-7 prevents TGF-beta1-induced EMT in primary (RPTEC) and immortalized (HK-2) human proximal tubule epithelial cells.

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Birds are uricotelic, and because they excrete urate by renal tubular secretion, they provide a convenient model for examination of this process. Primary monolayer cultures of the isolated renal proximal tubule epithelium from the domestic chicken, Gallus gallus L., were mounted in Ussing chambers where several substrates/inhibitors of renal organic anion transporters were tested for the sidedness and specificity of their effects on transepithelial urate transport.

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Previous studies have indicated that a major fraction of the filtered Cl(-) is reabsorbed via apical membrane Cl(-)/base exchange in the proximal tubule. Recent studies in Slc26a6 null mice have suggested that this transporter mediates only a portion of proximal tubule Cl(-)/base exchange, raising the possibility that one or more unidentified apical membrane transporters may additionally contribute. Recent studies have identified Slc26a7 as another Cl(-)/base exchanger expressed in the kidney.

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The mechanisms and control of transepithelial inorganic sulfate (Si) transport by primary cultures of chick renal proximal tubule monolayers in Ussing chambers were determined. The competitive anion, S2 O 3 2- (5 mM), reduced both unidirectional reabsorptive and secretory fluxes and net Si reabsorption with no effect on electrophysiological properties. The carbonic anhydrase (CA) inhibitor ethoxzolamide decreased net Si reabsorption approximately 45%.

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The effect of parathyroid hormone (PTH) and activation of protein kinase C (PKC) and protein kinase A (PKA) on transepithelial P(i) transport was examined in monolayers of chick proximal tubule cells in primary culture (PTCs). Acute exposure of the PTCs to PTH (10(-9) M, basolateral side) significantly decreased the net reabsorption of P(i) by approximately 66%. There was no effect after the addition of PTH to the luminal side.

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