Yu Z.,Indiana University |
Gunst S.J.,Indiana University |
Tepper R.S.,Wells Center for Pediatric Research |
Tepper R.S.,James Whitcomb Riley Hospital for Children
European Respiratory Journal | Year: 2013
Asthma is characterised by airway hyperreactivity, which is primarily treated with badrenergic bronchodilators and anti-inflammatory agents. However, mechanical strain during breathing is an important modulator of airway responsiveness and we have previously demonstrated in animal models that continuous positive airway pressure (CPAP) resulted in lower in vivo airway reactivity. We now evaluated whether using nocturnal CPAP decreased airway reactivity in clinically-stable adults with asthma. Adults with stable asthma and normal spirometry used nocturnal CPAP (8-10 cmH2O) or sham treatment (0-2 cmH2O) for 7 days. Spirometry and bronchial challenges were obtained before and after treatment. The primary outcome was the provocative concentration of methacholine causing a 20% fall in forced expiratory volume in 1 s (PC20). The CPAP group (n=16) had a significant decrease in airway reactivity (change in (D)logPC20 0.406, p<0.0017) while the sham group (n=9) had no significant change in airway reactivity (δlogPC20 0.003, p=0.9850). There was a significant difference in the change in airway reactivity for the CPAP versus the sham group (δlogPC20 0.41, p<0.043). Our findings indicate that chronic mechanical strain of the lungs produced using nocturnal CPAP for 7 days reduced airway reactivity in clinically stable asthmatics. Future studies of longer duration are required to determine whether CPAP can also decrease asthma symptoms and/or medication usage.
PubMed | Biostatistics and., Microbiology and Immunology., Wells Center for Pediatric Research, Indiana University and 4 more.
Type: Journal Article | Journal: The Journal of biological chemistry | Year: 2015
Apurinic/apyrimidinic endonuclease/redox factor-1 (APE1/Ref-1) (henceforth referred to as Ref-1) is a multifunctional protein that in addition to its base excision DNA repair activity exerts redox control of multiple transcription factors, including nuclear factor -light chain enhancer of activated B cells (NF-B), STAT3, activator protein-1 (AP-1), hypoxia-inducible factor-1 (HIF-1), and tumor protein 53 (p53). In recent years, Ref-1 has emerged as a promising therapeutic target in cancer, particularly in pancreatic ductal carcinoma. Although a significant amount of research has centered on Ref-1, no wide-ranging approach had been performed on the effects of Ref-1 inhibition and transcription factor activity perturbation. Starting with a broader approach, we identified a previously unsuspected effect on the nuclear factor erythroid-related factor 2 (NRF2), a critical regulator of cellular defenses against oxidative stress. Based on genetic and small molecule inhibitor-based methodologies, we demonstrated that repression of Ref-1 potently activates NRF2 and its downstream targets in a dose-dependent fashion, and that the redox, rather than the DNA repair function of Ref-1 is critical for this effect. Intriguingly, our results also indicate that this pathway does not involve reactive oxygen species. The link between Ref-1 and NRF2 appears to be present in all cells tested in vitro, noncancerous and cancerous, including patient-derived tumor samples. In particular, we focused on understanding the implications of the novel interaction between these two pathways in primary pancreatic ductal adenocarcinoma tumor cells and provide the first evidence that this mechanism has implications for overcoming the resistance against experimental drugs targeting Ref-1 activity, with clear translational implications.
Barnes R.M.,Wells Center for Pediatric Research |
Firulli B.A.,Wells Center for Pediatric Research |
Vandusen N.J.,Wells Center for Pediatric Research |
Morikawa Y.,Tulane University |
And 5 more authors.
Circulation Research | Year: 2011
Rationale: The basic helix-loop-helix (bHLH) transcription factors Hand1 and Hand2 are essential for embryonic development. Given their requirement for cardiogenesis, it is imperative to determine their impact on cardiovascular function. Objective: To deduce the role of Hand2 within the epicardium. Zmethod and Results: We engineered a Hand1 allele expressing Cre recombinase. Cardiac Hand1 expression is largely limited to cells of the primary heart field, overlapping little with Hand2 expression. Hand1 is expressed within the septum transversum, and the Hand1 lineage marks the proepicardial organ and epicardium. To examine Hand factor functional overlap, we conditionally deleted Hand2 from Hand1-expressing cells. Hand2 mutants display defective epicardialization and fail to form coronary arteries, coincident with altered extracellular matrix deposition and Pdgfr expression. Conclusions: These data demonstrate a hierarchal relationship whereby transient Hand1 septum transversum expression defines epicardial precursors that are subsequently dependent on Hand2 function. © 2011 American Heart Association, Inc.
Andersson O.,University of California at San Francisco |
Adams B.A.,University of California at San Francisco |
Yoo D.,University of California at San Francisco |
Ellis G.C.,University of California at San Francisco |
And 5 more authors.
Cell Metabolism | Year: 2012
Diabetes can be controlled with insulin injections, but a curative approach that restores the number of insulin-producing β cells is still needed. Using a zebrafish model of diabetes, we screened ∼7,000 small molecules to identify enhancers of β cell regeneration. The compounds we identified converge on the adenosine signaling pathway and include exogenous agonists and compounds that inhibit degradation of endogenously produced adenosine. The most potent enhancer of β cell regeneration was the adenosine agonist 5′-N-ethylcarboxamidoadenosine (NECA), which, acting through the adenosine receptor A2aa, increased β cell proliferation and accelerated restoration of normoglycemia in zebrafish. Despite markedly stimulating β cell proliferation during regeneration, NECA had only a modest effect during development. The proliferative and glucose-lowering effect of NECA was confirmed in diabetic mice, suggesting an evolutionarily conserved role for adenosine in β cell regeneration. With this whole-organism screen, we identified components of the adenosine pathway that could be therapeutically targeted for the treatment of diabetes. ©2012 Elsevier Inc.
Yang L.,Wells Center for Pediatric Research |
Xie G.,Wells Center for Pediatric Research |
Fan Q.,Wells Center for Pediatric Research |
Xie J.,Wells Center for Pediatric Research
Oncogene | Year: 2010
The hedgehog pathway, initially discovered by two Nobel laureates Drs E Wieschaus and C Nusslein-Volhard in Drosophila, is a major regulator for cell differentiation, tissue polarity and cell proliferation. Studies from many laboratories reveal activation of this pathway in a variety of human cancer, including basal cell carcinomas (BCCs), medulloblastomas, leukemia, gastrointestinal, lung, ovarian, breast and prostate cancers. It is thus believed that targeted inhibition of hedgehog signaling may be effective in treatment and prevention of human cancer. Even more exciting is the discovery and synthesis of specific signaling antagonists for the hedgehog pathway, which have significant clinical implications in novel cancer therapeutics. In this review, we will summarize major advances in the last 2 years in our understanding of hedgehog signaling activation in human cancer, interactions between hedgehog signaling and other pathways in carcinogenesis, potential antagonists for hedgehog signaling inhibition and their clinical implications for human cancer treatment. © 2010 Macmillan Publishers Limited All rights reserved.