Browsing by Author "Gracon, Adam"

Now showing 1 - 3 of 3
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    Crosstalk between TGF-β1 and complement activation augments epithelial injury in pulmonary fibrosis
    (Federation of American Societies for Experimental Biology, 2014-10) Gu, Hongmei; Mickler, Elizabeth A.; Cummings, Oscar W.; Sandusky, George E.; Weber, Daniel J.; Gracon, Adam; Woodruff, Trent; Wilkes, David S.; Vittal, Ragini; Department of Microbiology and Immunology, IU School of Medicine
    The epithelial complement inhibitory proteins (CIPs) cluster of differentiation 46 and 55 (CD46 and CD55) regulate circulating immune complex-mediated complement activation in idiopathic pulmonary fibrosis (IPF). Our previous studies demonstrated that IL-17A mediates epithelial injury via transforming growth factor β1 (TGF-β1) and down-regulates CIPs. In the current study, we examined the mechanistic role of TGF-β1 in complement activation-mediated airway epithelial injury in IPF pathogenesis. We observed lower epithelial CIP expression in IPF lungs compared to normal lungs, associated with elevated levels of complement component 3a and 5a (C3a and C5a), locally and systemically. In normal primary human small airway epithelial cells (SAECs) treated with TGF-β1 (10 ng/ml), C3a, or C5a (100 nM), we observed loss of CIPs and increased poly(ADP-ribose) polymerase (PARP) activation [also observed with RNA interference (RNAi) of CD46/CD55]. TGF-β1-mediated loss of CIPs and Snail induction [SNAI1; a transcriptional repressor of E-cadherin (E-CAD)] was blocked by inhibiting mitogen-activated protein kinase (p38MAPK; SB203580) and RNAi silencing of SNAI1. C3a- and C5a-mediated loss of CIPs was also blocked by p38MAPK inhibition. While C3a upregulated TGFb transcripts, both C3a and C5a down-regulated SMAD7 (negative regulator of TGF-β), and whereas TGF-β1 induced C3a/C5a receptor (C3aR/C5aR) expression, pharmacologic C3aR/C5aR inhibition protected against C3a-/C5a-mediated loss of CIPs. Taken together, our results suggest that epithelial injury in IPF can be collectively amplified as a result of TGF-β1-induced loss of CIPs leading to complement activation that down-regulates CIPs and induces TGF-β1 expression
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    Hypoxia-Inducible Factor-1α Regulates CD55 in Airway Epithelium
    (American Thoracic Society, 2016-12) Pandya, Pankita H.; Fisher, Amanda J.; Mickler, Elizabeth A.; Temm, Constance J.; Lipking, Kelsey P.; Gracon, Adam; Rothhaar, Katia; Sandusky, George E.; Murray, Mary; Pollok, Karen; Renbarger, Jamie; Blum, Janice S.; Lahm, Tim; Wilkes, David S.; Microbiology and Immunology, School of Medicine
    Airway epithelial CD55 down-regulation occurs in several hypoxia-associated pulmonary diseases, but the mechanism is unknown. Using in vivo and in vitro assays of pharmacologic inhibition and gene silencing, the current study investigated the role of hypoxia-inducible factor (HIF)-1α in regulating airway epithelial CD55 expression. Hypoxia down-regulated CD55 expression on small-airway epithelial cells in vitro, and in murine lungs in vivo; the latter was associated with local complement activation. Treatment with pharmacologic inhibition or silencing of HIF-1α during hypoxia-recovered CD55 expression in small-airway epithelial cells. HIF-1α overexpression or blockade, in vitro or in vivo, down-regulated CD55 expression. Collectively, these data show a key role for HIF-1α in regulating the expression of CD55 on airway epithelium.
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    Proteomic characterization reveals that MMP-3 correlates with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell and lung transplantation
    (Wiley, 2016-08) Liu, Xiaowen; Yue, Zongliang; Yu, Jeffrey; Daguindau, Etienne; Kushekhar, Kushi; Zhang, Qing; Ogata, Yuko; Gafken, Philip R.; Inamoto, Yoshihiro; Gracon, Adam; Wilkes, David S.; Hansen, John A.; Lee, Stephanie J.; Chen, Jake Yue; Paczesny, Sophie; BioHealth Informatics, School of Informatics and Computing
    Improved diagnostic methods are needed for bronchiolitis obliterans syndrome (BOS), a serious complication after allogeneic hematopoietic cell transplantation (HCT) and lung transplantation. For proteins candidate discovery, we compared plasma pools from HCT transplantation recipients with: BOS at onset (n=12), pulmonary infection (n=16), chronic graft-versus-host disease without pulmonary involvement (n=15), and no chronic complications post-HCT (n=15). Pools were labeled with different tags [isobaric Tags for Relative and Absolute Quantification (iTRAQ)], and two software tools identified differentially expressed proteins (≥1.5-fold change). Candidate proteins were further selected using a six-step computational biology approach. The diagnostic value of the lead candidate, matrix metalloproteinase-3 (MMP-3), was evaluated by ELISA in plasma of a verification cohort (n=112) with and without BOS following HCT (n=76) or lung transplantation (n=36). MMP-3 plasma concentrations differed significantly between patients with and without BOS (AUC=0.77). Thus, MMP-3 represents a potential non-invasive blood test for diagnosis of BOS.