105 results on '"Crean D"'
Search Results
2. NON-INVASIVE CARDIAC RADIOABLATION FOR RECURRENT VENTRICULAR TACHYCARDIA: INITIAL RESULTS AND INSIGHTS
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Redpath, C, primary, Crean, D, additional, Nair, G, additional, Birnie, D, additional, Sadek, M, additional, Cook, G, additional, Tiberi, D, additional, and Nery, P, additional
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- 2021
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3. A synchrotron X-ray spectroscopy study of titanium co-ordination in explosive melt glass derived from the trinity nuclear test
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Bailey, D. J., primary, Stennett, M. C., additional, Ravel, B., additional, Crean, D. E., additional, and Hyatt, N. C., additional
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- 2019
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4. Cytosporone B attenuates intestinal cytokine and chemokine production ex vivo
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Ismaiel, M., primary, Baird, A., additional, Winter, D., additional, and Crean, D., additional
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- 2018
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5. Adenosine Modulates NR4A Orphan Nuclear Receptors To Attenuate Hyperinflammatory Responses in Monocytic Cells
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Crean, D., Cummins, E. P., Bahar, Bojlul, Mohan, H., McMorrow, J. P., Murphy, E. P., Crean, D., Cummins, E. P., Bahar, Bojlul, Mohan, H., McMorrow, J. P., and Murphy, E. P.
- Abstract
Adenosine receptor–mediated regulation of monocyte/macrophage inflammatory responses is critical in the maintenance of tissue homeostasis. In this study, we reveal that adenosine potently modulates the expression of NR4A1, 2, and 3 orphan nuclear receptors in myeloid cells, and this modulation is primarily through the adenosine A2a receptor subtype. We demonstrate that A2a receptor activation of NR4A1-3 receptor synthesis is further enhanced in TLR4-stimulated monocytes. After TLR4 stimulation, NR4A receptor–depleted monocyte/macrophage cells display significantly altered expression of cell-surface markers and produce increased inflammatory cytokine and chemokine secretion rendering the cells an enhanced proinflammatory phenotype. Exposure of TLR4 or TNF-α–stimulated monocytes to adenosine analogs directs changes in the expression of MIP-3α and IL-23p19, with NR4A2 depletion leading to significantly enhanced expression of these factors. Furthermore, we establish that nuclear levels of NF-κB/p65 are increased in TLR/adenosine-stimulated NR4A2-depleted cells. We show that, after TLR/adenosine receptor stimulation, NR4A2 depletion promotes significant binding of NF-κB/p65 to a κB consensus binding motif within the MIP-3α proximal promoter leading to increased protein secretion, confirming a pivotal role for NF-κB activity in controlling cellular responses and gene expression outcomes in response to these mediators. Thus, these data demonstrate that during an inflammatory response, adenosine modulation of NR4A receptor activity acts to limit NF-κB–mediated effects and that loss of NR4A2 expression leads to enhanced NF-κB activity and hyperinflammatory responses in myeloid cells.
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- 2015
6. Acid components of fruit and vegetable I. Production of acids by thermal processing
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CREAN, D. E. C., primary
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- 2007
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7. Digital Photography: Enhancing Communication Between Burn Therapists and Nurses
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Van, Lan B., primary, Sicotte, K. M., additional, Lassiter, R. R., additional, Jablonski, K. A., additional, Crean, D. A., additional, Jeng, J. C., additional, and Jordan, M. H., additional
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- 2004
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8. Digital Photography: Enhancing Communication Between Burn Therapists and Nurses
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Van, L. B., primary, Dammen, K. M., additional, Lassiter, R. R., additional, Crean, D. A., additional, Jeng, J. C., additional, and Jordan, M. H., additional
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- 2003
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9. Surgeon Captain RWF Paul Royal Navy
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Crean, D M, primary
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- 2000
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10. A study of the effects of internal organ motion and setup error on dose escalation in conformal prostate treatments
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Happersett, L., primary, Crean, D., additional, Bull, S., additional, Lyass, O., additional, Mageras, G., additional, Zelefsky, M., additional, Burman, C., additional, Leibel, S., additional, Chui, C., additional, Fuks, Z., additional, van Herk, M., additional, Kooy, H., additional, Ling, C., additional, Mohan, R., additional, and Kutcher, G., additional
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- 1998
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11. 1012 Quantification of variation in organ position and volume during conformal radiotherapy of the prostate
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Crean, D., primary, Lyass, O., additional, Zelefsky, M.J., additional, Bull, S., additional, Mageras, G.S., additional, Luccio, V., additional, Fuks, Z., additional, Leibel, S.A., additional, Kooy, H.M., additional, van Herk, M., additional, and Kutcher, G.J., additional
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- 1996
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12. Synergistic effects of bombesin and epidermal growth factor on cancers.
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Liebow, C, primary, Crean, D H, additional, Lee, M T, additional, Kamer, A R, additional, Mang, T S, additional, and Schally, A V, additional
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- 1994
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13. Effects of oxandrolone on outcome measures in the severely burned: a multicenter prospective randomized double-blind trial.
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Wolf SE, Edelman LS, Kemalyan N, Donison L, Cross J, Underwood M, Spence RJ, Noppenberger D, Palmieri TL, Greenhalgh DG, Lawless M, Voigt D, Edwards P, Warner P, Kagan R, Hatfield S, Jeng J, Crean D, Hunt J, and Purdue G
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- 2006
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14. Equalization of amniotic fluid volumes after decompression amniocentesis for treatment of the twin oligohydramnios-polyhydramnios sequence.
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Bruner, Joseph P., Crean, Debbie M., Bruner, J P, and Crean, D M
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- 1999
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15. Evaluation of porfimer sodium fluorescence for measuring tissue transformation.
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Crean, David H., Liebow, Charles, Penetrante, Remedios B., Mang, Thomas S., Crean, D H, Liebow, C, Penetrante, R B, and Mang, T S
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- 1993
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16. Fluorescence detection of tumors. Early diagnosis of microscopic lesions in preclinical studies.
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Mang, Thomas S., McGinnis, Carolyn, Liebow, Charles, Nseyo, Unyime O., Crean, David H., Dougherty, Thomas J., Mang, T S, McGinnis, C, Liebow, C, Nseyo, U O, Crean, D H, and Dougherty, T J
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- 1993
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17. Osteitis Pubis as a Mimic of Prostatic Pain.
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BUCK, A. C., CREAN, D. M., and JENKINS, I. L.
- Abstract
- Thirty-five patients with pain suggesting a prostatic origin but with no evidence of active prostatic inflammation presented between 1979 and 1982 and were diagnosed as having osteitis pubis. The clinical presentation, diagnosis and treatment of osteitis pubis are presented together with the results of treatment. [ABSTRACT FROM AUTHOR]
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- 1982
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18. Photodynamic therapy and hyperthermia as an adjuvant modality in preventing tumor recurrence.
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Kübler, Alexander, Crean, David H., Kingsbury, Jeffrey, Liebow, Charles, Mang, Thomas S., Kübler, A, Crean, D H, Kingsbury, J, Liebow, C, and Mang, T S
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- 1997
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19. Acid components of fruit and vegetable I. Production of acids by thermal processing.
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CREAN, D. E. C.
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- 1966
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20. Elasticity coefficients and texture of cooked dried peas.
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Crean, D. E. C. and Haisman, D. R.
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- 1965
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21. The interaction between phytic acid and divalent cations during the cooking of dried peas.
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Crean, D. E. C. and Haisman, D. R.
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- 1963
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22. Quantification and predictors of prostate position variability in 50 patients evaluated with multiple CT scans during conformal radiotherapy
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Zelefsky, M. J., Crean, D., Mageras, G. S., Lyass, O., Happersett, L., Ling, C. Clifton, Leibel, S. A., Fuks, Z., Bull, S., and Kooy, H. M.
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- 1999
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23. Peptide analogues alter the progression of premalignant lesions, as measured by Photofrin fluorescence.
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Liebow, C, Crean, D H, Schally, A V, and Mang, T S
- Abstract
Somatostatin analogue RC-160 and bombesin/gastrin-releasing peptide antagonist RC-3095 were infused at 2 micrograms per day via miniosmotic pumps implanted s.c. in hamsters with premalignant disease to examine the effect of these peptides on cancer promotion and progression. These analogues have been shown to inhibit growth of certain tumors, especially those that overexpress tyrosine kinase activity. Progression of premalignant lesions initiated by applying 0.5% 9,10-dimethyl-1,2-benzanthracene (DMBA) to the hamster buccal cheek pouch was measured by Photofrin-induced fluorescence 24 hr after injecting the porphyrin (1.0 mg/kg) by using in vivo fluorescence photometry. This method of monitoring progression was reaffirmed by the observations that fluorescence increased significantly as compared with controls in lesions receiving 4 additional weeks of continuous promotion by DMBA application (P < 0.01 in two independent trials) and in lesions receiving transient promotion by laser incision (P < 0.01 and < 0.05 at the same time in the two trials). Twelve weeks after treatment, fluorescence had decreased significantly among animals treated for 2 weeks with RC-3095 (control, 0.53 +/- 0.03 V vs. RC-3095, 0.28 +/- 0.03 V; P < 0.0005) or with RC-160 (control, 0.85 +/- 0.03 V vs. RC-160, 0.24 +/- 0.03 V; P < 0.0001). These data were obtained 20 weeks after DMBA initiation. Thus, treatment with RC-160 and RC-3095 decreased the progression, measured by fluorescence, compared with control animals. In addition, there was also an absolute continuous decrease in fluorescence for the 22 weeks after the cessation of RC-160 treatment. That the changes in tumor progression produced by RC-160 extended beyond the treatment period supports the hypothesis that the changes were irreversible. Histopathological analysis revealed normal tissue and/or mild-moderate dysplasia in hamster buccal mucosa treated with the RC-160 (an improvement compared to pretreatment), whereas 40% of the animals receiving no treatment after DMBA initiation developed invasive squamous cell carcinomas after 20 weeks. These results show that the antagonists of bombesin/gastrin-releasing peptide can delay the development of malignancies and the agonists of somatostatin can potentially reverse this development.
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- 1993
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24. Cerebrospinal fluid alpha-fetoprotein in germ cell neoplasms.
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Penley, W C, Grosh, W W, Crean, D M, Hainsworth, J D, Greco, F A, and Parl, F F
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- 1988
25. Development of an in vitro renal epithelial disease state model for xenobiotic toxicity testing
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Crean D, Bellwon P, Aschauer L, Alice Limonciel, Moenks K, Hewitt P, Schmidt T, Herrgen K, Dekant W, Lukas A, Bois F, Wilmes A, Jennings P, and Mo, Leonard
26. Osteitis pubis as a mimic of prostatic pain
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Jenkins, I. L., primary, Crean, D. M., additional, and Buck, A. C., additional
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- 1984
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27. The third Colloquium on clinical problems related to sport
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Crean, D., primary
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- 1980
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28. Photographic Estimation of Plant Size1
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Sydnor, T. D., primary, Fretz, T. A., additional, Crean, D. E., additional, and Cobbs, M. R., additional
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- 1975
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29. Physical Fitness in the Prevention of Ischaemic Heart Disease
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Crean, D. M., primary
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- 1981
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30. The management of soft tissue ankle injuries.
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Crean, D., primary
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- 1981
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31. Salt free acidulant storage of pickling cucumbers
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Gould, W. A., Shoup, J. L., Geisman, J. R., and Crean, D. E.
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- 1975
32. A Novel Role for FERM Domain-Containing Protein 3 (FRMD3) in CKD.
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Kennedy C, Doyle R, Gough O, Mcevoy C, Anallen SM, Hughes M, Sheng X, Crifo B, Andrews D, Gaffney A, Rodriguez J, Kennedy S, Dillon E, Crean D, Zhang W, Yi Z, Nair V, Susztak K, Hirschhorn J, Florez J, Groop PH, Sandholm N, Kretzler M, Mckay GJ, Mcknight AJ, Maxwell AP, Matallanas D, Dorman A, Martin F, Conlon PJ, Sadlier DM, Brennan E, and Godson C
- Abstract
Background: Currently there are limited methods to link disease severity and risk of disease progression in Chronic Kidney Disease (CKD). To better understand this potential relationship, we interrogated the renal transcriptomic profile of individuals with CKD with measures of CKD severity and identified FERM-domain containing protein 3 (FRMD3) as a candidate gene for follow-up study., Methods: RNA-seq was used to profile the transcriptome of CKD biopsies from the North Dublin Renal BioBank the results of which were correlated with clinical parameters. The potential function of FRMD3 was explored by interrogating the FRMD3 interactome and assessing the impact of lentiviral mediated FRMD3 knock down on human renal proximal tubule epithelial cells by assessing cell viability, metabolic activity, and structural markers., Results: We identified a subset of 93 genes which are significantly correlated with estimated glomerular filtration rate and percentage tubulointerstitial fibrosis at time of biopsy and with CKD progression 5 years post-biopsy. These results were validated against transcriptomic data from an external cohort of 432 nephrectomy samples. One of the top-ranking genes from this subset, FRMD3, has previously been associated with the risk of developing diabetic kidney disease. Interrogating the interactome of FRMD3 in tubule epithelial cells revealed interactions with cytoskeletal components of cell-cell junctions. Knockdown of FRMD3 expression in tubule epithelial cells resulted in increased pro-apoptotic activity within the cells as well as dysregulation of E-Cadherin., Conclusions: We have identified a panel of kidney-specific transcripts correlated with severity and progression of kidney disease, and from this have identified a possible role for FRMD3 in tubule cell structure and health., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Nephrology.)
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- 2024
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33. Impact and Assessment of Research Integrity Teaching: A Systematic Literature Review.
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Crean D, Gordijn B, and Kearns AJ
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- Humans, Awareness, Scientific Misconduct ethics, Decision Making ethics, Ethics, Research education, Motivation, Teaching
- Abstract
Presented here is a systematic literature review of what the academic literature asserts about: (1) the stages of the ethical decision-making process (i.e. awareness, reasoning, motivation, and action) that are claimed to be improved or not improved by RI teaching and whether these claims are supported by evidence; (2) the measurements used to determine the effectiveness of RI teaching; and (3) the stage/s of the ethical decision-making process that are difficult to assess. Regarding (1), awareness was the stage most claimed to be amenable to improvement following RI teaching, and with motivation being the stage that is rarely addressed in the academic literature. While few, some sources claimed RI teaching cannot improve specific stages. With behaviour (action) being the stage referenced most, albeit in only 9% of the total sources, for not being amenable to improvement following RI teaching. Finally, most claims were supported by empirical evidence. Regarding (2), measures most frequently used are custom in-house surveys and some validated measures. Additionally, there is much debate in the literature regarding the adequacy of current assessment measures in RI teaching, and even their absence. Such debate warrants caution when we are considering the empirical evidence supplied to support that RI teaching does or does not improve a specific stage of the decision-making process. Regarding (3), only behaviour was discussed as being difficult to assess, if not impossible. In our discussion section we contextualise these results, and following this we derive some recommendations for relevant stakeholders in RI teaching., (© 2024. The Author(s).)
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- 2024
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34. Reproducible Synthesis of Biocompatible Albumin Nanoparticles Designed for Intra-articular Administration of Celecoxib to Treat Osteoarthritis.
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Khandelia R, Hodgkinson T, Crean D, Brougham DF, Scholz D, Ibrahim H, Quinn SJ, Rodriguez BJ, Kennedy OD, O'Byrne JM, and Brayden DJ
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- Animals, Humans, Celecoxib pharmacology, Celecoxib therapeutic use, Injections, Intra-Articular, Knee Joint, Albumins, Osteoarthritis drug therapy, Nanoparticles
- Abstract
Osteoarthritis (OA) is the most common form of arthritis, with intra-articular (IA) delivery of therapeutics being the current best option to treat pain and inflammation. However, IA delivery is challenging due to the rapid clearance of therapeutics from the joint and the need for repeated injections. Thus, there is a need for long-acting delivery systems that increase the drug retention time in joints with the capacity to penetrate OA cartilage. As pharmaceutical utility also demands that this is achieved using biocompatible materials that provide colloidal stability, our aim was to develop a nanoparticle (NP) delivery system loaded with the COX-2 inhibitor celecoxib that can meet these criteria. We devised a reproducible and economical method to synthesize the colloidally stable albumin NPs loaded with celecoxib without the use of any of the following conditions: high temperatures at which albumin denaturation occurs, polymer coatings, oils, Class 1/2 solvents, and chemical protein cross-linkers. The spherical NP suspensions were biocompatible, monodisperse with average diameters of 72 nm (ideal for OA cartilage penetration), and they were stable over 6 months at 4 °C. Moreover, the NPs loaded celecoxib at higher levels than those required for the therapeutic response in arthritic joints. For these reasons, they are the first of their kind. Labeled NPs were internalized by primary human articular chondrocytes cultured from the knee joints of OA patients. The NPs reduced the concentration of inflammatory mediator prostaglandin E
2 released by the primaries, an indication of retained bioactivity following NP synthesis. Similar results were observed in lipopolysaccharide-stimulated human THP-1 monocytes. The IA administration of these NPs is expected to avoid side-effects associated with oral administration of celecoxib and to maintain a high local concentration in the knee joint over a sustained period. They are now ready for evaluation by IA administration in animal models of OA.- Published
- 2024
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35. Orphan Nuclear Receptor Family 4A (NR4A) Members NR4A2 and NR4A3 Selectively Modulate Elements of the Monocyte Response to Buffered Hypercapnia.
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Phelan DE, Reddan B, Shigemura M, Sznajder JI, Crean D, and Cummins EP
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- Humans, Monocytes metabolism, Hypercapnia, Carbon Dioxide, Nuclear Receptor Subfamily 4, Group A, Member 1 genetics, Nuclear Receptor Subfamily 4, Group A, Member 2 genetics, DNA-Binding Proteins, Receptors, Thyroid Hormone, Orphan Nuclear Receptors genetics, Receptors, Steroid metabolism
- Abstract
Hypercapnia occurs when the partial pressure of carbon dioxide (CO
2 ) in the blood exceeds 45 mmHg. Hypercapnia is associated with several lung pathologies and is transcriptionally linked to suppression of immune and inflammatory signalling through poorly understood mechanisms. Here we propose Orphan Nuclear Receptor Family 4A (NR4A) family members NR4A2 and NR4A3 as potential transcriptional regulators of the cellular response to hypercapnia in monocytes. Using a THP-1 monocyte model, we investigated the sensitivity of NR4A family members to CO2 and the impact of depleting NR4A2 and NR4A3 on the monocyte response to buffered hypercapnia (10% CO2 ) using RNA-sequencing. We observed that NR4A2 and NR4A3 are CO2 -sensitive transcription factors and that depletion of NR4A2 and NR4A3 led to reduced CO2 -sensitivity of mitochondrial and heat shock protein (Hsp)-related genes, respectively. Several CO2 -sensitive genes were, however, refractory to depletion of NR4A2 and NR4A3, indicating that NR4As regulate certain elements of the cellular response to buffered hypercapnia but that other transcription factors also contribute. Bioinformatic analysis of conserved CO2 -sensitive genes implicated several novel putative CO2 -sensitive transcription factors, of which the ETS Proto-Oncogene 1 Transcription Factor (ETS-1) was validated to show increased nuclear expression in buffered hypercapnia. These data give significant insights into the understanding of immune responses in patients experiencing hypercapnia.- Published
- 2024
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36. Teaching research integrity as discussed in research integrity codes: A systematic literature review.
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Crean D, Gordijn B, and Kearns AJ
- Abstract
Presented here is a systematic literature review of how RI teaching is discussed in national and international research integrity (RI) codes. First, we set out to identify the codes that exist, and performed some generic analysis on them. Following a comprehensive search strategy, which included all 193 United Nations member states, we identified 52 national and 14 international RI codes. RI teaching is addressed in 46 national and 10 international codes. We then examined how the codes address RI teaching under the following headings: the aims, the target audience, the ethics approach proposed, the assessment and/or evaluation strategy, and any challenges identified in relation to RI teaching. There is considerable overlap between the aims of RI teaching in the various codes, for example, promoting awareness of RI. Most codes claim RI teaching is for all researchers, but without any in-depth guidance. While educational programmes, training, and mentorship/supervision are proposed for RI teaching, there is insufficient detail to identify the ethics approach to be used in such teaching. Lastly, only few address assessment and/or evaluation or challenges in RI teaching. Here, we analyzed how current codes address RI teaching; we identified some shortfalls, and in our discussion we advance recommendations.
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- 2023
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37. Hypercapnia alters mitochondrial gene expression and acylcarnitine production in monocytes.
- Author
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Phelan DE, Mota C, Strowitzki MJ, Shigemura M, Sznajder JI, Crowe L, Masterson JC, Hayes SE, Reddan B, Yin X, Brennan L, Crean D, and Cummins EP
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- Humans, Animals, Mice, Carbon Dioxide, Monocytes metabolism, Genes, Mitochondrial, Lipopolysaccharides, Gene Expression, Fatty Acids, Hypercapnia etiology, Hypercapnia metabolism, Pulmonary Disease, Chronic Obstructive complications
- Abstract
CO
2 is produced during aerobic respiration. Normally, levels of CO2 in the blood are tightly regulated but pCO2 can rise (hypercapnia, pCO2 > 45 mmHg) in patients with lung diseases, for example, chronic obstructive pulmonary disease (COPD). Hypercapnia is a risk factor in COPD but may be of benefit in the context of destructive inflammation. The effects of CO2 per se, on transcription, independent of pH change are poorly understood and warrant further investigation. Here we elucidate the influence of hypercapnia on monocytes and macrophages through integration of state-of-the-art RNA-sequencing, metabolic and metabolomic approaches. THP-1 monocytes and interleukin 4-polarized primary murine macrophages were exposed to 5% CO2 versus 10% CO2 for up to 24 h in pH-buffered conditions. In hypercapnia, we identified around 370 differentially expressed genes (DEGs) under basal and about 1889 DEGs under lipopolysaccharide-stimulated conditions in monocytes. Transcripts relating to both mitochondrial and nuclear-encoded gene expression were enhanced in hypercapnia in basal and lipopolysaccharide-stimulated cells. Mitochondrial DNA content was not enhanced, but acylcarnitine species and genes associated with fatty acid metabolism were increased in hypercapnia. Primary macrophages exposed to hypercapnia also increased activation of genes associated with fatty acid metabolism and reduced activation of genes associated with glycolysis. Thus, hypercapnia elicits metabolic shifts in lipid metabolism in monocytes and macrophages under pH-buffered conditions. These data indicate that CO2 is an important modulator of monocyte transcription that can influence immunometabolic signaling in immune cells in hypercapnia. These immunometabolic insights may be of benefit in the treatment of patients experiencing hypercapnia., (© 2023 The Authors. Immunology & Cell Biology published by John Wiley & Sons Australia, Ltd on behalf of the Australian and New Zealand Society for Immunology, Inc.)- Published
- 2023
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38. NR4A1-3 nuclear receptor activity and immune cell dysregulation in rheumatic diseases.
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Murphy EP and Crean D
- Abstract
The development and progression of immune-mediated rheumatic disease (IMRD) involves dysfunction of innate and adaptive immune cell populations leading to altered responses including inflammasome activation, dysregulated cytokine networks, increased immune cell numbers and multifaceted cell-cell communication. Several rheumatic diseases are further characterized by the presence of autoantibodies, immune complex mediated complement activation and the deficit of peripheral immune tolerance due to reduced regulatory T-lymphocyte cell function. Ultimately, in rheumatic disease the loss in cellular and tissue homeostasis culminates in the advancement of chronic inflammation. The three members of the NR4A subfamily of nuclear receptors are immediate early genes, and act as potent transcriptional responders to changes in the cellular and tissue microenvironment. Subfamily members are rapidly expressed in diseases characterized by inflammation and function to control the differentiation and activity of innate and adaptive immune cells in a cell-type and cell-context specific manner. Rheumatic disease including rheumatoid-, psoriatic-, osteo-arthritis and systemic sclerosis display altered NR4A1-3 activity in controlling immune cell migration and function, production of paracrine signaling molecules, synovial tissue hyperplasia, and regulating cartilage turn-over in vivo . Additionally, NR4A1-3 activities mediate cytokine, prostanoid and growth factor signaling to control angiogenesis, modulate the regulatory functions of mesenchymal stromal cells, alter the activation status of dendritic cells, influence the generation of peripheral myeloid and T-lymphocyte lineages and promote the maintenance of functional regulatory T-cells. Further reports uncover the potential of moderating NR4A 1-3 receptors as therapeutic targets in altering immune tolerance, pathological angiogenesis and controlling inflammation in several models of disease., (Copyright © 2022 Murphy and Crean.)
- Published
- 2022
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39. Transcriptional Profiling of Monocytes Deficient in Nuclear Orphan Receptors NR4A2 and NR4A3 Reveals Distinct Signalling Roles Related to Antigen Presentation and Viral Response.
- Author
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Phelan DE, Shigemura M, Aldhafiri S, Mota C, Hall TJ, Sznajder JI, Murphy EP, Crean D, and Cummins EP
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- Antigen Presentation drug effects, Cell Movement drug effects, Cell Movement genetics, Computational Biology methods, DNA-Binding Proteins genetics, Gene Expression Regulation drug effects, Gene Knockdown Techniques, Humans, Lipopolysaccharides pharmacology, Nuclear Receptor Subfamily 4, Group A, Member 2 genetics, RNA-Seq methods, Receptors, Steroid genetics, Receptors, Thyroid Hormone genetics, THP-1 Cells, Transcriptome drug effects, Antigen Presentation genetics, DNA-Binding Proteins metabolism, Monocytes immunology, Monocytes virology, Nuclear Receptor Subfamily 4, Group A, Member 2 metabolism, Receptors, Steroid metabolism, Receptors, Thyroid Hormone metabolism, Signal Transduction genetics, Transcriptome genetics
- Abstract
The nuclear receptor sub-family 4 group A (NR4A) family are early response genes that encode proteins that are activated in several tissues/cells in response to a variety of stressors. The NR4A family comprises NR4A1 , NR4A2 and NR4A3 of which NR4A2 and NR4A3 are under researched and less understood, particularly in the context of immune cells. NR4A expression is associated with multiple diseases e.g. arthritis and atherosclerosis and the development of NR4A-targetting molecules as therapeutics is a current focus in this research field. Here, we use a combination of RNA-sequencing coupled with strategic bioinformatic analysis to investigate the down-stream effects of NR4A2 and NR4A3 in monocytes and dissect their common and distinct signalling roles. Our data reveals that NR4A2 and NR4A3 depletion has a robust and broad-reaching effect on transcription in both the unstimulated state and in the presence of LPS. Interestingly, many of the genes affected were present in both the unstimulated and stimulated states revealing a previously unappreciated role for the NR4As in unstimulated cells. Strategic clustering and bioinformatic analysis identified both distinct and common transcriptional roles for NR4A2 and NR4A3 in monocytes. NR4A2 notably was linked by both bioinformatic clustering analysis and transcription factor interactome analysis to pathways associated with antigen presentation and regulation of MHC genes. NR4A3 in contrast was more closely linked to pathways associated with viral response. Functional studies further support our data analysis pointing towards preferential/selective roles for NR4A2 in the regulation of antigen processing with common roles for NR4A2 and NR4A3 evident with respect to cell migration. Taken together this study provides novel mechanistic insights into the role of the enigmatic nuclear receptors NR4A2 and NR4A3 in monocytes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Phelan, Shigemura, Aldhafiri, Mota, Hall, Sznajder, Murphy, Crean and Cummins.)
- Published
- 2021
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40. Protein kinase D, ubiquitin and proteasome pathways are involved in adenosine receptor-stimulated NR4A expression in myeloid cells.
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Giffney HE, Cummins EP, Murphy EP, Brayden DJ, and Crean D
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- Adenosine administration & dosage, Adenosine metabolism, Adenosine pharmacology, Adenosine-5'-(N-ethylcarboxamide) administration & dosage, Adenosine-5'-(N-ethylcarboxamide) pharmacology, DNA-Binding Proteins metabolism, Humans, NF-kappa B metabolism, Nuclear Receptor Subfamily 4, Group A, Member 1 metabolism, Receptors, Steroid metabolism, Receptors, Thyroid Hormone metabolism, THP-1 Cells, Ubiquitin metabolism, Myeloid Cells metabolism, Orphan Nuclear Receptors metabolism, Proteasome Endopeptidase Complex metabolism, Protein Kinase C metabolism, Receptors, Purinergic P1 metabolism
- Abstract
Adenosine is a purine nucleoside pivotal for homeostasis in cells and tissues. Stimulation of the adenosine receptors (AR) has been shown to regulate the nuclear orphan receptor 4A (NR4A1-3) family, resulting in attenuation of hyper-inflammatory responses in myeloid cells. The NR4A1-3 orphan receptors are early immediate response genes and transcriptional regulators of cell and tissue homeostasis. The signal transduction and transcriptional mechanism(s) of how AR-stimulation promotes NR4A expression in myeloid cells is unknown and is the focus of this study. We confirm that adenosine and the stable analogue, 5'-N-Ethylcarboxamidoadenosine (NECA), enhance NR4A1-3 expression in THP-1 cells. Pharmacological approaches identified that protein kinase D (PKD) mediates AR-stimulated NR4A expression in myeloid cells and reveals no involvement of PKA nor PKC. The role of NF-κB, a principal regulator of NR4A expression in myeloid cells, was examined as a possible transcriptional regulator downstream of PKD. Utilising BAY11-7082 and MG-132, inhibitors of the respective ubiquitin and proteasome pathways essential for NF-κB activation, suggested a prospective role for NF-κB, or more specifically signalling via IKKα/β. However, biological interventional studies using overexpression of IκBα in myeloid cells and MEF cells lacking IKKα and IKKβ (IKKα/β
-/- ) revealed the NF-κB pathway is not utilised in mediating AR-stimulated NR4A expression. Thus, this study contributes mechanistic insight into how AR signalling modulates the expression of NR4A receptors, pivotal regulators of inflammatory responses in myeloid cells., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest associated with this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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41. The NR4A agonist, Cytosporone B, attenuates pro-inflammatory mediators in human colorectal cancer tissue ex vivo.
- Author
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Ismaiel M, Murphy B, Aldhafiri S, Giffney HE, Thornton K, Mukhopadhya A, Keogh CE, Fattah S, Mohan HM, Cummins EP, Murphy EP, Winter DC, and Crean D
- Subjects
- Adult, Aged, Aged, 80 and over, Chemokines metabolism, Colorectal Neoplasms immunology, Colorectal Neoplasms metabolism, Colorectal Neoplasms pathology, Cytokines metabolism, Female, Humans, Inflammation immunology, Inflammation metabolism, Inflammation pathology, Male, Middle Aged, Colorectal Neoplasms drug therapy, Inflammation Mediators metabolism, Nuclear Receptor Subfamily 4, Group A, Member 1 agonists, Phenylacetates pharmacology
- Abstract
Inflammation is a pivotal pathological factor in colorectal cancer (CRC) initiation and progression, and modulating this inflammatory state has the potential to ameliorate disease progression. NR4A receptors have emerged as key regulators of inflammatory pathways that are important in CRC. Here, we have examined the effect of NR4A agonist, Cytosporone B (CsnB), on colorectal tissue integrity and its effect on the inflammatory profile in CRC tissue ex vivo. Here, we demonstrate concentrations up 100 μM CsnB did not adversely affect tissue integrity as measured using transepithelial electrical resistance, histology and crypt height. Subsequently, we reveal through the use of a cytokine/chemokine array, ELISA and qRT-PCR analysis that multiple pro-inflammatory mediators were significantly increased in CRC tissue compared to control tissue, which were then attenuated with the addition of CsnB (such as IL-1β, IL-8 and TNFα). Lastly, stratification of the data revealed that CsnB especially alters the inflammatory profile of tumours derived from males who had not undergone chemoradiotherapy. Thus, this study demonstrates that NR4A agonist CsnB does not adversely affect colon tissue structure or functionality and can attenuate the pro-inflammatory state of human CRC tissue ex vivo., Competing Interests: Declaration of competing interest The authors of the article below declare no conflicts of interest associated with this article., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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42. Targeting NR4A Nuclear Receptors to Control Stromal Cell Inflammation, Metabolism, Angiogenesis, and Tumorigenesis.
- Author
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Crean D and Murphy EP
- Abstract
The NR4A1-NR4A3 (Nur77, Nurr1, and Nor-1) subfamily of nuclear receptors is a group of immediate early genes induced by a pleiotropy of stimuli including peptide hormones, growth factors, cytokines, inflammatory, and physiological stimuli, and cellular stress. NR4A receptors function as potent sensors of changes in the cellular microenvironment to control physiological and pathological processes through genomic and non-genomic actions. NR4A receptors control metabolism and cardiovascular and neurological functions and mediate immune cell homeostasis in inflammation and cancer. This receptor subfamily is increasingly recognized as an important molecular connection between chronic inflammation, altered immune cell responses, and cancer development. In this review, we examine how transcriptome analysis identified NR4A1/NR4A2 receptors as transcriptional regulators in mesenchymal stromal cell (MSC) migration, cell cycle progression, and cytokine production to control local immune responses. In chronic inflammatory conditions, such as rheumatoid arthritis, NR4A receptors have been shown to modify the activity of MSC and fibroblast-like stromal cells to regulate synovial tissue hyperplasia, pathological angiogenesis, and cartilage turnover in vivo . Additionally, as NR4A1 has been observed as a major transcriptional regulator in tumor-stromal communication controlling tumorigenesis, we discuss how advances in the pharmacological control of these receptors lead to important new mechanistic insights into understanding the role of the tumor microenvironment in health and disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Crean and Murphy.)
- Published
- 2021
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43. HIF hydroxylase inhibitors decrease cellular oxygen consumption depending on their selectivity.
- Author
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Sulser P, Pickel C, Günter J, Leissing TM, Crean D, Schofield CJ, Wenger RH, and Scholz CC
- Subjects
- HEK293 Cells, Humans, Protein Domains, Energy Metabolism drug effects, Enzyme Inhibitors pharmacology, Hypoxia-Inducible Factor-Proline Dioxygenases antagonists & inhibitors, Hypoxia-Inducible Factor-Proline Dioxygenases metabolism, Oxygen metabolism, Oxygen Consumption drug effects
- Abstract
Pharmacologic HIF hydroxylase inhibitors (HIs) are effective for the treatment of anemia in chronic kidney disease patients and may also be beneficial for the treatment of diseases such as chronic inflammation and ischemia-reperfusion injury. The selectivities of many HIs for HIF hydroxylases and possible off-target effects in cellulo are unclear, delaying the translation from preclinical studies to clinical trials. We developed a novel assay that discriminates between the inhibition of HIF-α prolyl-4-hydroxylase domain (PHD) enzymes and HIF-α asparagine hydroxylase factor inhibiting HIF (FIH). We characterized 15 clinical and preclinical HIs, categorizing them into pan-HIF-α hydroxylase (broad spectrum), PHD-selective, and FIH-selective inhibitors, and investigated their effects on HIF-dependent transcriptional regulation, erythropoietin production, and cellular energy metabolism. While energy homeostasis was generally maintained following HI treatment, the pan-HIs led to a stronger increase in pericellular pO
2 than the PHD/FIH-selective HIs. Combined knockdown of FIH and PHD-selective inhibition did not further increase pericellular pO2 . Hence, the additional increase in pericellular pO2 by pan- over PHD-selective HIs likely reflects HIF hydroxylase independent off-target effects. Overall, these analyses demonstrate that HIs can lead to oxygen redistribution within the cellular microenvironment, which should be considered as a possible contributor to HI effects in the treatment of hypoxia-associated diseases., (© 2019 Federation of American Societies for Experimental Biology.)- Published
- 2020
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44. Hydroxylase Inhibition Selectively Induces Cell Death in Monocytes.
- Author
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Crifo B, Schaible B, Brown E, Halligan DN, Scholz CC, Fitzpatrick SF, Kirwan A, Roche HM, Criscuoli M, Naldini A, Giffney H, Crean D, Blanco A, Cavadas MA, Cummins EP, Fabian Z, and Taylor CT
- Subjects
- Cell Death drug effects, Cell Death immunology, Cells, Cultured, HEK293 Cells, Humans, Inflammation immunology, Inflammation metabolism, Mixed Function Oxygenases immunology, Mixed Function Oxygenases metabolism, Monocytes immunology, Monocytes metabolism, Amino Acids, Dicarboxylic pharmacology, Inflammation drug therapy, Mixed Function Oxygenases antagonists & inhibitors, Monocytes drug effects, Prolyl-Hydroxylase Inhibitors pharmacology
- Abstract
Hypoxia is a common and prominent feature of the microenvironment at sites of bacteria-associated inflammation in inflammatory bowel disease. The prolyl-hydroxylases (PHD1/2/3) and the asparaginyl-hydroxylase factor-inhibiting HIF are oxygen-sensing enzymes that regulate adaptive responses to hypoxia through controlling the activity of HIF and NF-κB-dependent transcriptional pathways. Previous studies have demonstrated that the pan-hydroxylase inhibitor dimethyloxalylglycine (DMOG) is effective in the alleviation of inflammation in preclinical models of inflammatory bowel disease, at least in part, through suppression of IL-1β-induced NF-κB activity. TLR-dependent signaling in immune cells, such as monocytes, which is important in bacteria-driven inflammation, shares a signaling pathway with IL-1β. In studies into the effect of pharmacologic hydroxylase inhibition on TLR-induced inflammation in monocytes, we found that DMOG selectively triggers cell death in cultured THP-1 cells and primary human monocytes at concentrations well tolerated in other cell types. DMOG-induced apoptosis was independent of increased caspase-3/7 activity but was accompanied by reduced expression of the inhibitor of apoptosis protein 1 (cIAP1). Based on these data, we hypothesize that pharmacologic inhibition of the HIF-hydroxylases selectively targets monocytes for cell death and that this may contribute to the anti-inflammatory activity of HIF-hydroxylase inhibitors., (Copyright © 2019 by The American Association of Immunologists, Inc.)
- Published
- 2019
- Full Text
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45. Subcellular Localization of NR4A2 Orphan Nuclear Receptor Expression in Human and Mouse Synovial Joint Tissue.
- Author
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Smyth A, Gogarty M, Crean D, and Murphy EP
- Subjects
- Animals, Disease Models, Animal, Humans, Mice, Protein Transport, Arthritis, Rheumatoid metabolism, Immunohistochemistry methods, Nuclear Receptor Subfamily 4, Group A, Member 2 analysis, Nuclear Receptor Subfamily 4, Group A, Member 2 metabolism, Synovial Membrane metabolism
- Abstract
NR4A1-3 receptors are required in inflammatory disease initiation and progression, where they function as early response regulators, controlling the extent of the inflammatory response and promoting inflammatory resolution. NR4A receptor activity controls inflammatory processes in several diseases characterized by chronic inflammation including rheumatoid arthritis (RA) and atherosclerosis. Studies indicate that cell-type and cellular microenvironment can alter NR4A1-3 receptor activity and influence their biological roles. Thus, the study of appropriate in vivo models of inflammatory disease is important to ascertain their cell- and tissue-specific functional roles. Here we describe immunohistochemical approaches optimized to study the expression patterns of NR4A nuclear receptors in inflamed synovium tissues obtained from patients diagnosed with RA and mouse models of inflammatory joint disease.
- Published
- 2019
- Full Text
- View/download PDF
46. Lipoxins Protect Against Inflammation in Diabetes-Associated Atherosclerosis.
- Author
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Brennan EP, Mohan M, McClelland A, de Gaetano M, Tikellis C, Marai M, Crean D, Dai A, Beuscart O, Derouiche S, Gray SP, Pickering R, Tan SM, Godson-Treacy M, Sheehan S, Dowdall JF, Barry M, Belton O, Ali-Shah ST, Guiry PJ, Jandeleit-Dahm K, Cooper ME, Godson C, and Kantharidis P
- Subjects
- Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Atherosclerosis etiology, Chemokine CCL2 metabolism, Cytokines metabolism, Diabetes Mellitus, Experimental complications, Humans, Inflammation etiology, Interleukin-1beta metabolism, Interleukin-6 metabolism, Lipoxins pharmacology, Mice, Vascular Cell Adhesion Molecule-1 metabolism, Anti-Inflammatory Agents, Non-Steroidal therapeutic use, Aorta drug effects, Atherosclerosis drug therapy, Diabetes Mellitus, Experimental drug therapy, Inflammation drug therapy, Lipoxins therapeutic use
- Abstract
Increasing evidence points to the fact that defects in the resolution of inflammatory pathways predisposes individuals to the development of chronic inflammatory diseases, including diabetic complications such as accelerated atherosclerosis. The resolution of inflammation is dynamically regulated by the production of endogenous modulators of inflammation, including lipoxin A4 (LXA
4 ). Here, we explored the therapeutic potential of LXA4 and a synthetic LX analog (Benzo-LXA4 ) to modulate diabetic complications in the streptozotocin-induced diabetic ApoE-/- mouse and in human carotid plaque tissue ex vivo. The development of diabetes-induced aortic plaques and inflammatory responses of aortic tissue, including the expression of vcam-1 , mcp-1 , il-6 , and il-1β , was significantly attenuated by both LXA4 and Benzo-LXA4 in diabetic ApoE-/- mice. Importantly, in mice with established atherosclerosis, treatment with LXs for a 6-week period, initiated 10 weeks after diabetes onset, led to a significant reduction in aortic arch plaque development (19.22 ± 2.01% [diabetic]; 12.67 ± 1.68% [diabetic + LXA4 ]; 13.19 ± 1.97% [diabetic + Benzo-LXA4 ]). Secretome profiling of human carotid plaque explants treated with LXs indicated changes to proinflammatory cytokine release, including tumor necrosis factor-α and interleukin-1β. LXs also inhibited platelet-derived growth factor-stimulated vascular smooth muscle cell proliferation and transmigration and endothelial cell inflammation. These data suggest that LXs may have therapeutic potential in the context of diabetes-associated vascular complications., (© 2018 by the American Diabetes Association.)- Published
- 2018
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- View/download PDF
47. Intra-articular delivery of a nanocomplex comprising salmon calcitonin, hyaluronic acid, and chitosan using an equine model of joint inflammation.
- Author
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Sladek S, Kearney C, Crean D, Brama PAJ, Tajber L, Fawcett K, Labberte MC, Leggett B, and Brayden DJ
- Subjects
- Animals, Arthrocentesis, Biomarkers metabolism, Calcitonin pharmacology, Chitosan pharmacology, Disease Models, Animal, Drug Carriers chemistry, Horses, Hyaluronic Acid pharmacology, Injections, Intra-Articular, Lipopolysaccharides adverse effects, Nanoconjugates toxicity, Pilot Projects, Synovial Fluid metabolism, Synovitis chemically induced, Synovitis metabolism, Calcitonin administration & dosage, Chitosan administration & dosage, Hyaluronic Acid administration & dosage, Nanoconjugates chemistry, Synovitis drug therapy
- Abstract
Polyelectrolyte nanoparticle constructs (NPs) comprising salmon calcitonin (sCT), chitosan (CS), and hyaluronic acid (HA) were previously established as having anti-inflammatory potential when injected via the intra-articular (i.a.) route to a mouse model. We attempted to translate the formulation to a large animal model, the lipopolysaccharide (LPS)-stimulated equine model of joint inflammation. The aim was to manufacture under aseptic conditions to produce sterile pyrogen-free NPs, to confirm physicochemical characteristics, and to test toxicity and efficacy in a pilot study. NP dispersions were successfully formulated using pharmaceutical-grade source materials and were aseptically manufactured under GMP-simulated conditions in a grade A modular aseptic processing workstation. The NP formulation had no detectable pathogen or endotoxin contamination. NPs were then tested versus a lactated Ringer's solution control following single i.a. injections to the radiocarpal joints of two groups of four horses pre-treated with LPS, followed by arthrocentesis at set intervals over 1 week. There was no evidence of treatment-related toxicity over the period. While there were no differences between clinical read-outs of the NP and the control, two synovial fluid-derived biomarkers associated with cartilage turnover revealed a beneficial effect of NPs. In conclusion, NPs comprising well-known materials were manufactured for an equine i.a.-injectable pilot study and yielded no NP-attributable toxicity. Evidence of NP-associated benefit at the level of secondary endpoints was detected as a result of decreases in synovial fluid inflammatory biomarkers.
- Published
- 2018
- Full Text
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48. Liraglutide dictates macrophage phenotype in apolipoprotein E null mice during early atherosclerosis.
- Author
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Bruen R, Curley S, Kajani S, Crean D, O'Reilly ME, Lucitt MB, Godson CG, McGillicuddy FC, and Belton O
- Subjects
- Animals, Atherosclerosis drug therapy, Cell Line, Humans, Hypoglycemic Agents pharmacology, Leukocytes, Mononuclear drug effects, Leukocytes, Mononuclear metabolism, Liraglutide pharmacology, Macrophages drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Apolipoproteins E deficiency, Atherosclerosis metabolism, Hypoglycemic Agents therapeutic use, Liraglutide therapeutic use, Macrophages metabolism, Phenotype
- Abstract
Background: Macrophages play a pivotal role in atherosclerotic plaque development. Recent evidence has suggested the glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, can attenuate pro-inflammatory responses in macrophages. We hypothesized that liraglutide could limit atherosclerosis progression in vivo via modulation of the inflammatory response., Methods: Human THP-1 macrophages and bone marrow-derived macrophages, from both wild-type C57BL/6 (WT) and apolipoprotein E null mice (ApoE
-/- ) were used to investigate the effect of liraglutide on the inflammatory response in vitro. In parallel, ApoE-/- mice were fed a high-fat (60% calories from fat) high-cholesterol (1%) diet for 8 weeks to induce atherosclerotic disease progression with/without daily 300 μg/kg liraglutide administration for the final 6 weeks. Macrophages were analysed for MΦ1 and MΦ2 macrophage markers by Western blotting, RT-qPCR, ELISA and flow cytometry. Atherosclerotic lesions in aortae from ApoE-/- mice were analysed by en face staining and monocyte and macrophage populations from bone marrow derived cells analysed by flow cytometry., Results: Liraglutide decreased atherosclerotic lesion formation in ApoE-/- mice coincident with a reduction in pro-inflammatory and increased anti-inflammatory monocyte/macrophage populations in vivo. Liraglutide decreased IL-1beta in MΦ0 THP-1 macrophages and bone marrow-derived macrophages from WT mice and induced a significant increase in the MΦ2 surface marker mannose receptor in both MΦ0 and MΦ2 macrophages. Significant reduction in total lesion development was found with once daily 300 μg/kg liraglutide treatment in ApoE-/- mice. Interestingly, liraglutide inhibited disease progression at the iliac bifurcation suggesting that it retards the initiation and development of disease. These results corresponded to attenuated MΦ1 markers (CCR7, IL-6 and TNF-alpha), augmented MΦ2 cell markers (Arg-1, IL-10 and CD163) and finally decreased MΦ1-like monocytes and macrophages from bone marrow-derived cells., Conclusions: This data supports a therapeutic role for liraglutide as an atheroprotective agent via modulating macrophage cell fate towards MΦ2 pro-resolving macrophages.- Published
- 2017
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49. Hypoxia and inflammatory bowel disease.
- Author
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Cummins EP and Crean D
- Subjects
- Animals, Humans, Inflammatory Bowel Diseases therapy, Hypoxia complications, Hypoxia physiopathology, Inflammatory Bowel Diseases etiology, Inflammatory Bowel Diseases physiopathology
- Abstract
Inflammatory bowel disease (IBD) is a general term to describe inflammatory diseases of the gastrointestinal tract such as Crohn's disease and ulcerative colitis. IBD affects approximately 1 in 200 individuals and exerts a significant health and quality of life burden on patients. Surgical intervention can be curative in ulcerative colitis but there is currently no cure for Crohn's disease. Since this is the case, and the fact that patients are often diagnosed at a young age, IBD exerts a significant financial burden on the health care system, and society as a whole. The underlying pathology of IBD is complex and involves a combination of genetic, environmental and microbial factors. Regardless of the underlying causes of the condition, this disease is universally characterized by disruption to the protective epithelial barrier separating the intestinal lumen above from the mucosal immune system below. Once this barrier becomes compromised a sequence of events ensues, that can occur in repetitive cycles to ensure long-term and serious damage to the gut. The role of hypoxia and hypoxia-dependent signalling pathways are increasingly appreciated to play a role in the physiology and pathophysiology of the intestine. The intestinal epithelium normally exists in a state of physiological hypoxia, with additional tissue hypoxia a feature of active inflammatory disease. Furthermore, recent pre-clinical animal studies have clearly supported the rationale for pharmacologically manipulating the oxygen-sensitive hypoxia-inducible factor (HIF) pathway in models of IBD. Thus, this review will discuss the contribution of hypoxia sensitive pathways in the pathology of IBD. Finally we will discuss the emerging evidence for manipulation of hypoxia-sensitive pathways in the treatment of IBD., (Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
50. NR4A Receptors Differentially Regulate NF-κB Signaling in Myeloid Cells.
- Author
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McEvoy C, de Gaetano M, Giffney HE, Bahar B, Cummins EP, Brennan EP, Barry M, Belton O, Godson CG, Murphy EP, and Crean D
- Abstract
Dysregulation of inflammatory responses is a hallmark of multiple diseases such as atherosclerosis and rheumatoid arthritis. As constitutively active transcription factors, NR4A nuclear receptors function to control the magnitude of inflammatory responses and in chronic inflammatory disease can be protective or pathogenic. Within this study, we demonstrate that TLR4 stimulation using the endotoxin lipopolysaccharide (LPS) rapidly enhances NR4A1-3 expression in human and murine, primary and immortalized myeloid cells with concomitant gene transcription and protein secretion of MIP-3α, a central chemokine implicated in numerous pathologies. Deficiency of NR4A2 and NR4A3 in human and murine myeloid cells reveals that both receptors function as positive regulators of enhanced MIP-3α expression. In contrast, within the same cell types and conditions, altered NR4A activity leads to suppression of LPS-induced MCP-1 gene and protein expression. An equivalent pattern of inflammatory gene regulation is replicated in TNFα-treated myeloid cells. We show that NF-κB is the critical regulator of NR4A1-3, MIP-3α, and MCP-1 during TLR4 stimulation in myeloid cells and highlight a parallel mechanism whereby NR4A activity can repress or enhance NF-κB target gene expression simultaneously. Mechanistic insight reveals that NR4A2 does not require DNA-binding capacity in order to enhance or repress NF-κB target gene expression simultaneously and establishes a role for NF-κB family member Relb as a novel NR4A target gene involved in the positive regulation of MIP-3α. Thus, our data reveal a dynamic role for NR4A receptors concurrently enhancing and repressing NF-κB activity in myeloid cells leading to altered transcription of key inflammatory mediators.
- Published
- 2017
- Full Text
- View/download PDF
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