Research interests

  • Interests
    Human Physiology

Publications

  • 10.69
    Impact points
    Macrophage Migration Inhibitory Factor Enzymatic Activity, Lung Inflammation and Cystic Fibrosis.

    Huzaifa Adamali, Michelle E Armstrong, Anne Marie McLaughlin, Gordon Cooke, Edward McKone, Christine M Costello, Charles G Gallagher, Lin Leng, John A Baugh, Günter Fingerle-Rowson, Richard J Bucala, Paul McLoughlin, Seamas C Donnelly

    American journal of respiratory and critical care medicine. 05/2012;

    RATIONALE: Macrophage migration inhibitory factor (MIF) is a pro-inflammatorymediator with unique tautomerase enzymatic activity; the precise function has notbeen clearly defined. We previously demonstrated that individual CF patients that are genetically predisposed to be high MIF producers develop... [more] RATIONALE: Macrophage migration inhibitory factor (MIF) is a pro-inflammatorymediator with unique tautomerase enzymatic activity; the precise function has notbeen clearly defined. We previously demonstrated that individual CF patients that are genetically predisposed to be high MIF producers develop accelerated end organ injury. OBJECTIVES: To characterize the effects of the MIF-CATT polymorphism in CFpatients ex vivo. To investigate the role of MIF's tautomerase activity in a murinemodel of Pseudomonas aeruginosa infection. METHODS: MIF and TNF-α protein levels were assessed in plasma or PBMCsupernatants by ELISA. A murine pulmonary model of chronic Pseudomonasinfection was utilized in MIF wild-type mice (mif+/+) and in tautomerase-null, MIFgene knock-in mice (mif P1G/P1G). MEASUREMENTS: MIF protein was measured in plasma and PBMCs from 5- and 6-CATT CF patients; LPS-induced TNF-α production from PBMCs was also assessed.The effect of a specific inhibitor of MIF-tautomerase activity, ISO-1, was investigated in PBMCs. In the murine infection model, total weight loss, differential cell counts, bacterial load and intra-acinar airspace/tissue volume was measured. RESULTS: MIF and TNF-α levels were increased in 6-CATT compared with 5-CATTCF patients. LPS-induced TNF-α production from PBMCs was attenuated in thepresence of ISO-1. In a murine model of Pseudomonas infection, significantly lesspulmonary inflammation and bacterial load was observed in mif P1G/P1G compared with mif+/+ mice. CONCLUSIONS: MIF-tautomerase activity may provide a novel therapeutic target inpatients with chronic inflammatory diseases such as CF, particularly those patientswho are genetically predisposed to produce increased levels of this cytokine.
  • 3.25
    Impact points
    Long-term statin therapy in patients with systolic heart failure and normal cholesterol: effects on elevated serum markers of collagen turnover, inflammation, and B-type natriuretic peptide.

    Esam Abulhul, Kenneth McDonald, Ramon Martos, Dermot Phelan, J Paul Spiers, Martina Hennessy, John Baugh, Chris Watson, Christina O'Loughlin, Mark Ledwidge

    Clinical therapeutics. 12/2011; 34(1):91-100.

    The role of statin therapy in heart failure (HF) is unclear. The amino-terminal propeptide of procollagen type III (PIIINP) predicts outcome in HF, and yet there are conflicting reports of statin therapy effects on PIIINP. This study determined whether there was an increase in serum markers of infla... [more] The role of statin therapy in heart failure (HF) is unclear. The amino-terminal propeptide of procollagen type III (PIIINP) predicts outcome in HF, and yet there are conflicting reports of statin therapy effects on PIIINP. This study determined whether there was an increase in serum markers of inflammation, fibrosis (including PIIINP), and B-type natriuretic peptide (BNP) in patients with systolic HF and normal total cholesterol and determined the effects of long-term treatment with atorvastatin on these markers. Fifty-six white patients with systolic HF and normal cholesterol levels (age 72 [13] years; 68% male; body mass index 27.0 [7.3] kg/m(2); ejection fraction 35 [13]%; 46% with history of smoking) were randomly allocated to atorvastatin treatment for 6 months, titrated to 40 mg/d (A group) or not (C group). Age- and/or sex-matched subjects without HF (N group) were also recruited. Biomarkers were measured at baseline (all groups) and 6 months (A and C groups). Serum markers of collagen turnover, inflammation, and BNP were significantly elevated in HF patients compared with normal participants (all P < 0.05). There were correlations between these markers in HF patients but not in normal subjects. Atorvastatin treatment for 6 months caused a significant reduction in the following biomarkers compared with baseline: BNP, from median (interquartile range) 268 (190-441) pg/mL to 185 (144-344) pg/mL; high-sensitivity C-reactive protein (hs-CRP), from 5.26 (1.95 -9.29) mg/L to 3.70 (2.34-6.81) mg/L; and PIIINP, from 4.65 (1.86) to 4.09 (1.25) pg/mL (all P < 0.05 baseline vs 6 months). Between-group differences were significant for PIIINP only (P = 0.027). There was a positive interaction between atorvastatin effects and baseline hs-CRP and PIIINP (P < 0.01). Long-term statin therapy reduced PIIINP in this small, selected HF population with elevated baseline levels. Further evaluation of statin therapy in the management of HF patients with elevated PIIINP is warranted.
  • 3.71
    Impact points
    Can emerging biomarkers of myocardial remodelling identify asymptomatic hypertensive patients at risk for diastolic dysfunction and diastolic heart failure?

    Patrick Collier, Chris J Watson, Victor Voon, Dermot Phelan, Aftab Jan, George Mak, Ramon Martos, John A Baugh, Mark T Ledwidge, Kenneth M McDonald

    European journal of heart failure. 06/2011; 13(10):1087-95.

    Hypertension is one of the main drivers of the heart failure (HF) epidemic. The aims of this study were to profile fibro-inflammatory biomarkers across stages of the hypertensive heart disease (HHD) spectrum and to examine whether particular biochemical profiles in asymptomatic patients identify a h... [more] Hypertension is one of the main drivers of the heart failure (HF) epidemic. The aims of this study were to profile fibro-inflammatory biomarkers across stages of the hypertensive heart disease (HHD) spectrum and to examine whether particular biochemical profiles in asymptomatic patients identify a higher risk of evolution to HF. This was a cross-sectional observational study involving a population of 275 stable hypertensive patients divided into two different cohorts: Group 1, asymptomatic hypertension (AH) (n= 94); Group 2, HF with preserved ejection fraction (n= 181). Asymptomatic hypertension patients were further subdivided according to left atrial volume index ≥34 mL/m(2) (n= 30) and <34 mL/m(2) (n= 64). Study assays involved inflammatory markers [interleukin 6 (IL6), interleukin 8 (IL8), monocyte chemoattractant protein 1 (MCP1), and tumour necrosis factor α], collagen 1 and 3 metabolic markers [carboxy-terminal propeptide of collagen 1, amino-terminal propeptide of collagen 1, amino-terminal propeptide of collagen 3 (PIIINP), and carboxy-terminal telopeptide of collagen 1 (CITP)], extra-cellular matrix turnover markers [matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), and tissue inhibitor of metalloproteinase 1 (TIMP1)], and the brain natriuretic peptide. Data were adjusted for age, sex, systolic blood pressure, and creatinine. Heart failure with preserved ejection fraction was associated with an increased inflammatory signal (IL6, IL8, and MCP1), an increased fibrotic signal (PIIINP and CITP), and an increased matrix turnover signal (MMP2 and MMP9). Alterations in MMP and TIMP enzymes were found to be significant indicators of greater degrees of asymptomatic left ventricular diastolic dysfunction. These data define varying fibro-inflammatory profiles throughout different stages of HHD. In particular, the observations on MMP9 and TIMP1 raise the possibility of earlier detection of those at risk of evolution to HF which may help focus effective preventative strategies.
  • 3.43
    Impact points
    Proteomic analysis of coronary sinus serum reveals leucine-rich α2-glycoprotein as a novel biomarker of ventricular dysfunction and heart failure.

    Chris J Watson, Mark T Ledwidge, Dermot Phelan, Patrick Collier, Jennifer C Byrne, Michael J Dunn, Kenneth M McDonald, John A Baugh

    Circulation. Heart failure. 01/2011; 4(2):188-97.

    Heart failure (HF) prevention strategies require biomarkers that identify disease manifestation. Increases in B-type natriuretic peptide (BNP) correlate with increased risk of cardiovascular events and HF development. We hypothesize that coronary sinus serum from a high BNP hypertensive population r... [more] Heart failure (HF) prevention strategies require biomarkers that identify disease manifestation. Increases in B-type natriuretic peptide (BNP) correlate with increased risk of cardiovascular events and HF development. We hypothesize that coronary sinus serum from a high BNP hypertensive population reflects an active pathological process and can be used for biomarker exploration. Our aim was to discover differentially expressed disease-associated proteins that identify patients with ventricular dysfunction and HF. Coronary sinus serum from 11 asymptomatic, hypertensive patients underwent quantitative differential protein expression analysis by 2-dimensional difference gel electrophoresis. Proteins were identified using mass spectrometry and then studied by enzyme-linked immunosorbent assay in sera from 40 asymptomatic, hypertensive patients and 105 patients across the spectrum of ventricular dysfunction (32 asymptomatic left ventricular diastolic dysfunction, 26 diastolic HF, and 47 systolic HF patients). Leucine-rich α2-glycoprotein (LRG) was consistently overexpressed in high BNP serum. LRG levels correlate significantly with BNP in hypertensive, asymptomatic left ventricular diastolic dysfunction, diastolic HF, and systolic HF patient groups (P≤0.05). LRG levels were able to identify HF independent of BNP. LRG correlates with coronary sinus serum levels of tumor necrosis factor-α (P=0.009) and interleukin-6 (P=0.021). LRG is expressed in myocardial tissue and correlates with transforming growth factor-βR1 (P<0.001) and α-smooth muscle actin (P=0.025) expression. LRG was identified as a serum biomarker that accurately identifies patients with HF. Multivariable modeling confirmed that LRG is a stronger identifier of HF than BNP and this is independent of age, sex, creatinine, ischemia, β-blocker therapy, and BNP.
  • 4.58
    Impact points
    Epigenetics, the epicenter of the hypoxic response.

    Jenny A Watson, Chris J Watson, Amanda McCann, John Baugh

    Epigenetics : official journal of the DNA Methylation Society. 05/2010; 5(4):293-6.

    It is becoming increasingly apparent that epigenetics plays a crucial role in the cellular response to hypoxia. Such epigenetic regulation may work hand in hand with the hypoxia-induced transcription factor (HIF) family or may contribute in a more substantial way to the maintenance of a hypoxia-adap... [more] It is becoming increasingly apparent that epigenetics plays a crucial role in the cellular response to hypoxia. Such epigenetic regulation may work hand in hand with the hypoxia-induced transcription factor (HIF) family or may contribute in a more substantial way to the maintenance of a hypoxia-adapted cellular phenotype long after HIF has initiated the immediate response pathways. In this article we discuss the current research implicating epigenetic mechanisms in the cellular response to hypoxic environments. This includes; the role of epigenetics in both the stabilization and binding of HIF to its transcriptional targets, the role of histone demethylase enzymes following direct HIF transactivation, and finally, the impact of hypoxic environments on global patterns of histone modifications and DNA methylation.
  • 12.54
    Impact points
    Natural history of markers of collagen turnover in patients with early diastolic dysfunction and impact of eplerenone.

    George J Mak, Mark T Ledwidge, Chris J Watson, Dermot M Phelan, Ian R Dawkins, Niamh F Murphy, Anil K Patle, John A Baugh, Kenneth M McDonald

    Journal of the American College of Cardiology. 10/2009; 54(18):1674-82.

    OBJECTIVES: This study was designed to evaluate the impact of eplerenone on collagen turnover in preserved systolic function heart failure (HFPSF). BACKGROUND: Despite growing interest in abnormal collagen metabolism as a feature of HFPSF with diastolic dysfunction, the natural history of markers of... [more] OBJECTIVES: This study was designed to evaluate the impact of eplerenone on collagen turnover in preserved systolic function heart failure (HFPSF). BACKGROUND: Despite growing interest in abnormal collagen metabolism as a feature of HFPSF with diastolic dysfunction, the natural history of markers of collagen turnover and the impact of selective aldosterone antagonism on this natural history remains unknown. METHODS: We evaluated 44 patients with HFPSF, randomly assigned to control (n = 20) or eplerenone 25 mg daily (n = 24) for 6 months, increased to 50 mg daily from 6 to 12 months. Serum markers of collagen turnover and inflammation were analyzed at baseline and at 6 and 12 months and included pro-collagen type-I and -III aminoterminal peptides, matrix metalloproteinase type-2, interleukin-6 and -8, and tumor necrosis factor-alpha. Doppler-echocardiographic assessment of diastolic filling indexes and tissue Doppler analyses were also obtained. RESULTS: The mean age of the patients was 80 +/- 7.8 years; 46% were male; 64% were receiving an angiotensin-converting enzyme inhibitor, 34% an angiotensin-II receptor blocker, and 68% were receiving beta-blocker therapy. Pro-collagen type-III and -I aminoterminal peptides, matrix metalloproteinase type-2, interleukin-6 and -8, and tumor necrosis factor-alpha increased with time in the control group. Eplerenone treatment had no significant impact on any biomarker at 6 months but attenuated the increase in pro-collagen type-III aminoterminal peptide at 12 months (p = 0.006). Eplerenone therapy was associated with modest effects on diastolic function without any impact on clinical variables or brain natriuretic peptide. CONCLUSIONS: This study demonstrates progressive increases in markers of collagen turnover and inflammation in HFPSF with diastolic dysfunction. Despite high background utilization of renin-angiotensin-aldosterone modulators, eplerenone therapy prevents a progressive increase in pro-collagen type-III aminoterminal peptide and may have a role in management of this disease. (The Effect of Eplerenone and Atorvastatin on Markers of Collagen Turnover in Diastolic Heart Failure; NCT00505336).
  • 7.39
    Impact points
    Generation of an epigenetic signature by chronic hypoxia in prostate cells.

    Jenny A Watson, Chris J Watson, Ann Maria McCrohan, Kathryn Woodfine, Miriam Tosetto, Jennifer McDaid, Emma Gallagher, David Betts, John Baugh, Jacintha O'Sullivan, Adele Murrell, R William G Watson, Amanda McCann

    Human molecular genetics. 08/2009;

    Increasing levels of tissue hypoxia have been reported as a natural feature of the aging prostate gland and may be a risk factor for the development of prostate cancer. In this study we have used PwR-1E benign prostate epithelial cells and an equivalently aged hypoxia-adapted PwR-1E sub-line to iden... [more] Increasing levels of tissue hypoxia have been reported as a natural feature of the aging prostate gland and may be a risk factor for the development of prostate cancer. In this study we have used PwR-1E benign prostate epithelial cells and an equivalently aged hypoxia-adapted PwR-1E sub-line to identify phenotypic and epigenetic consequences of chronic hypoxia in prostate cells. We have identified a significantly altered cellular phenotype in response to chronic hypoxia as characterised by increased receptor-mediated apoptotic resistance, the induction of cellular senescence, increased invasion and the increased secretion of IL1b, IL6, IL8 and TNF cytokines. In association with these phenotypic changes and the absence of HIF-1alpha protein expression we have demonstrated significant increases in global levels of DNA methylation and H3K9 histone acetylation in these cells, concomitant with the increased expression of DNA methyltransferase DMNT3b and gene-specific changes in DNA methylation at key imprinting loci. In conclusion, we have demonstrated a genome-wide adjustment of DNA methylation and histone acetylation under chronic hypoxic conditions in the prostate. These epigenetic signatures may represent an additional mechanism to promote and maintain a hypoxic-adapted cellular phenotype with a potential role in tumour development.
  • 5.65
    Impact points
    The Golgi-associated protein p115 mediates the secretion of macrophage migration inhibitory factor.

    Melanie Merk, John Baugh, Swen Zierow, Lin Leng, Utpal Pal, Seung-Joon Lee, Antje D Ebert, Yuka Mizue, John O Trent, Robert Mitchell, Walter Nickel, Paula B Kavathas, Jürgen Bernhagen, Richard Bucala

    Journal of immunology (Baltimore, Md. : 1950). 07/2009; 182(11):6896-906.

    Macrophage migration inhibitory factor (MIF) is a leaderless protein that is secreted from cells by a specialized, nonclassical export pathway. The release of MIF nevertheless is regulated and its production in response to different inflammatory, mitogenic, and hormonal stimuli plays an important ro... [more] Macrophage migration inhibitory factor (MIF) is a leaderless protein that is secreted from cells by a specialized, nonclassical export pathway. The release of MIF nevertheless is regulated and its production in response to different inflammatory, mitogenic, and hormonal stimuli plays an important role in diverse physiologic and pathologic processes. We report herein the identification of the Golgi complex-associated protein p115 as an intracellular binding partner for MIF. MIF interacts with p115 in the cytoplasm and the stimulated secretion of MIF results in the accumulation of both proteins in supernatants, which is consistent with MIF release from cells in conjunction with p115. The depletion of p115 from monocytes/macrophages decreases the release of MIF but not other cytokines following inflammatory stimulation or intracellular bacterial infection. Notably, the small molecule MIF inhibitor 4-iodo-6-phenylpyrimidine inhibits MIF secretion by targeting the interaction between MIF and p115. These data reveal p115 to be a critical intermediary component in the regulated secretion of MIF from monocytes/macrophages.
  • 3.71
    Impact points
    Diagnosis of heart failure with preserved ejection fraction: improved accuracy with the use of markers of collagen turnover.

    Ramón Martos, John Baugh, Mark Ledwidge, Christina O'Loughlin, Niamh F Murphy, Carmel Conlon, Anil Patle, Seamas C Donnelly, Kenneth McDonald

    European journal of heart failure : journal of the Working Group on Heart Failure of the European Society of Cardiology. 02/2009; 11(2):191-7.

    AIMS: Heart failure with preserved ejection fraction (HF-PEF) can be difficult to diagnose in clinical practice. Myocardial fibrosis is a major determinant of diastolic dysfunction (DD), potentially contributing to the progression of HF-PEF. The aim of this study was to analyse whether serological m... [more] AIMS: Heart failure with preserved ejection fraction (HF-PEF) can be difficult to diagnose in clinical practice. Myocardial fibrosis is a major determinant of diastolic dysfunction (DD), potentially contributing to the progression of HF-PEF. The aim of this study was to analyse whether serological markers of collagen turnover may predict HF-PEF and DD. METHODS AND RESULTS: We included 85 Caucasian treated hypertensive patients (DD n = 65; both DD and HF-PEF n = 32). Serum carboxy (PICP), amino (PINP), and carboxytelo (CITP) peptides of procollagen type I, amino (PIIINP) peptide of procollagen type III, matrix metalloproteinases (MMP-1, MMP-2, and MMP-9), and tissue inhibitor of MMP levels were assayed. Using receiver operating characteristic curve analysis, MMP-2 (AUC = 0.91; 95% CI: 0.84, 0.98), CITP (0.83; 0.72, 0.92), PICP (0.82; 0.72, 0.92), B-type natriuretic peptide (BNP) (0.82; 0.73, 0.91), MMP-9 (0.79; 0.68, 0.89), and PIIINP (0.78; 0.66, 0.89) levels were significant predictors of HF-PEF (P < 0.01 for all). Carboxytelo peptides of procollagen type I (AUC = 0.74; 95% CI: 0.62, 0.86), MMP-2 (0.73; 0.62, 0.84), PIIINP (0.73; 0.60, 0.85), BNP (0.69; 0.55, 0.83) and PICP (0.66; 0.54, 0.78) levels were significant predictors of DD (P < 0.05 for all). A cutoff of 1585 ng/mL for MMP-2 provided 91% sensitivity and 76% specificity for predicting HF-PEF and combinations of biomarkers could be used to adjust either sensitivity or specificity. CONCLUSION: Markers of collagen turnover identify patients with HF-PEF and DD. Matrix metalloproteinase 2 may be more useful than BNP in the identification of HF-PEF. This suggests that these new biochemical tools may assist in identifying patients with these diagnostically challenging conditions.
  • 5.65
    Impact points
    Small interfering RNAs induce macrophage migration inhibitory factor production and proliferation in breast cancer cells via a double-stranded RNA-dependent protein kinase-dependent mechanism.

    Michelle E Armstrong, Michael Gantier, Lili Li, Wen Y Chung, Amanda McCann, John A Baugh, Seamas C Donnelly

    Journal of immunology (Baltimore, Md. : 1950). 06/2008; 180(11):7125-33.

    Small interfering RNAs (siRNAs) represent a novel tool to induce gene silencing in mammalian cells and clinical trials are currently ongoing to assess the therapeutic efficacy of siRNAs in various human diseases, including age-related macular degeneration and respiratory syncytial virus infection. H... [more] Small interfering RNAs (siRNAs) represent a novel tool to induce gene silencing in mammalian cells and clinical trials are currently ongoing to assess the therapeutic efficacy of siRNAs in various human diseases, including age-related macular degeneration and respiratory syncytial virus infection. However, previously reported off-target, nonspecific effects of siRNAs, including activation of type I IFNs and proinflammatory cytokines, remain an outstanding concern regarding use of these agents in vivo. Macrophage-migration inhibitory factor (MIF) is a pleiotropic cytokine with well-described roles in cell proliferation, tumorigenesis, and angiogenesis and represents a target gene for siRNA-based therapy in the treatment of breast cancer. However, in this study we describe an increase in MIF production from mammary adenocarcinoma (MCF-7) cells following transfection with MIF siRNA and various control siRNAs. This effect was shown to be dose-dependent and was attenuated in the presence of a double-stranded RNA-dependent protein kinase inhibitor, 2-aminopurine. Furthermore, treatment of MCF-7 cells with poly(I:C) also stimulated a PKR-dependent increase in MIF production from MCF-7 cells. The biological consequence of the siRNA-induced increase in MIF production from MCF-7 cells was a PKR-dependent increase in proliferation of breast cancer cells. Furthermore, in cDNAs prepared from a primary human breast cancer cohort, we demonstrated a significant correlation (Spearman rank correlation coefficient, r = 0.50, p < 0.0001, n = 63) between PKR- and MIF-mRNA expression. In conclusion, this study highlights the potential biological consequences of off-target, nonspecific effects of siRNAs and underlines the safety concerns regarding the use of siRNAs in the treatment of human diseases, such as cancer.
  • 5.65
    Impact points
    A role for macrophage migration inhibitory factor in the neonatal respiratory distress syndrome.

    Katharine A Kevill, Vineet Bhandari, Mika Kettunen, Lin Leng, Juan Fan, Yuka Mizue, James D Dzuira, Miguel Reyes-Mugica, Courtney L McDonald, John A Baugh, Christine L O'Connor, Zubair H Aghai, Seamas C Donnelly, Alia Bazzy-Asaad, Richard J Bucala

    Journal of immunology (Baltimore, Md. : 1950). 01/2008; 180(1):601-8.

    Using a mouse model of neonatal respiratory distress syndrome (RDS), we demonstrate a central role for macrophage migration inhibitory factor (MIF) in lung maturation at the developmental stage when human neonates are most susceptible to RDS. We prematurely delivered mouse pups at embryonic day 18, ... [more] Using a mouse model of neonatal respiratory distress syndrome (RDS), we demonstrate a central role for macrophage migration inhibitory factor (MIF) in lung maturation at the developmental stage when human neonates are most susceptible to RDS. We prematurely delivered mouse pups at embryonic day 18, during the early saccular stage of pulmonary development. Only 8% of the prematurely delivered pups genetically deficient in MIF survived 8 h vs 75% of wild-type controls (p<0.001). This phenotype was corrected when pups of all genotypes were bred from dams heterozygote for MIF deficiency. Local production of MIF in the lung increased at embryonic day 18, continued until full-term at embryonic day 19.5, and decreased in adulthood, thus coinciding with this developmental window. The lungs of pups genetically deficient in MIF were less mature upon histological evaluation, and demonstrated lower levels of vascular endothelial growth factor and corticosterone--two factors that promote fetal lung maturation. In vitro studies support a role for MIF in surfactant production by pulmonary epithelial cells. In a cohort of human neonates with RDS, higher intrapulmonary MIF levels were associated with a lower likelihood of developing bronchopulmonary dysplasia, a sequelae of RDS (p<0.03). This study demonstrates for the first time a role for MIF in lung maturation, and supports a protective role for MIF in newborn lung disease.
  • 1.63
    Impact points
    Nuclear transcription of long hairpin RNA triggers innate immune responses.

    Michael P Gantier, John A Baugh, Seamas C Donnelly

    Journal of interferon & cytokine research : the official journal of the International Society for Interferon and Cytokine Research. 10/2007; 27(9):789-97.

    RNA interference (RNAi) is one of the most promising tools for deciphering the human genome and has great therapeutic potential. However, its high target specificity limits its efficiency for therapeutic protection from viruses with high rates of genetic mutation. This limitation may be overcome by ... [more] RNA interference (RNAi) is one of the most promising tools for deciphering the human genome and has great therapeutic potential. However, its high target specificity limits its efficiency for therapeutic protection from viruses with high rates of genetic mutation. This limitation may be overcome by the expression of long hairpin RNAs (lhRNAs). Indeed, lhRNAs have been shown recently to have increased efficacy over short interfering RNAs (siRNAs) as protective antiviral agents. Here, we investigate the expression of lhRNAs and demonstrate unintended effects. We show that overexpressed lhRNAs are exported to the cytoplasm. As a consequence, we detect activation of innate immune signaling pathways by lhRNAs. With growing concerns about the complexity of cytoplasmic detection of dsRNAs by the innate immune machinery, this work highlights the need for closer scrutiny when using lhRNAs as potential antiviral agents.
  • 3.57
    Impact points
    Role of proteomics in the investigation of pulmonary fibrosis.

    Praveen Govender, John A Baugh, Stephen R Pennington, Michael J Dunn, Seamas C Donnelly

    Expert review of proteomics. 07/2007; 4(3):379-88.

    Pulmonary fibrosis arises as a consequence of aberrant remodeling and defective repair mechanisms within the lung. This destructive process is the cause of much of the morbidity and mortality in many pulmonary disorders. Unfortunately, therapeutic options are limited. A significant advancement in th... [more] Pulmonary fibrosis arises as a consequence of aberrant remodeling and defective repair mechanisms within the lung. This destructive process is the cause of much of the morbidity and mortality in many pulmonary disorders. Unfortunately, therapeutic options are limited. A significant advancement in the management of patients with pulmonary fibrosis would be the identification of biomarkers for diagnosis, prognosis and prediction of patient response to therapy. Bronchoalveolar lavage is an ideal tissue target for the discovery of these potential biomarkers in pulmonary fibrosis. Integrative approaches using both gel- and mass spectrometry-based proteomic workflows will allow full coverage of this complex proteome, thereby unlocking this potential information as a clinical tool to aid diagnosis and guide treatment for individual patients with pulmonary fibrosis.
  • 14.82
    Impact points
    Diastolic heart failure: evidence of increased myocardial collagen turnover linked to diastolic dysfunction.

    Ramón Martos, John Baugh, Mark Ledwidge, Christina O'Loughlin, Carmel Conlon, Anil Patle, Seamas C Donnelly, Kenneth McDonald

    Circulation. 02/2007; 115(7):888-95.

    BACKGROUND: The pathophysiology of diastolic heart failure (DHF) is poorly understood. One potential explanation is an active fibrotic process that produces increased ventricular stiffness, which compromises filling. The present study investigates collagen metabolism in hypertensive patients in diff... [more] BACKGROUND: The pathophysiology of diastolic heart failure (DHF) is poorly understood. One potential explanation is an active fibrotic process that produces increased ventricular stiffness, which compromises filling. The present study investigates collagen metabolism in hypertensive patients in different phases of diastolic function with and without proven DHF. METHODS AND RESULTS: We studied 86 hypertensive patients divided into groups according to the presence of DHF (32 with, 54 without) and phase of diastolic function (20 with normal function, 38 with impaired relaxation, 10 with pseudonormalization, and 16 with restrictive-like filling). Serum carboxy-terminal, amino-terminal, and carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, matrix metalloproteinases (MMPs; total MMP-1, active MMP-2, and MMP-9), and tissue inhibitor of MMPs levels were assayed by radioimmunoassay and ELISA. Doppler-echocardiographic assessment of diastolic filling was made with measurements of E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Serum carboxy-terminal telopeptide of procollagen type I, carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, MMP-2, and MMP-9 levels (P<0.001 for all, controlled for age and gender) were greater in patients with DHF than in those without. When we controlled for age and gender, levels of serum carboxy-terminal telopeptide of procollagen type I, tissue inhibitor of MMP-1, amino-terminal propeptide of procollagen type III (all P<0.001), carboxy-terminal telopeptide of procollagen type I (P=0.008), and MMP-2 (P=0.03) were greater in more severe phases of diastolic dysfunction. Within phases of diastolic dysfunction, serum carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, MMP-2, and MMP-9 were elevated in those with DHF compared with those without DHF (all P<0.001). CONCLUSIONS: These data demonstrate serological evidence of an active fibrotic process in DHF, which is more marked in more severe diastolic dysfunction. This observation may help explain the pathophysiology of DHF and may suggest new avenues for diagnostic and therapeutic intervention.
  • 2.55
    Impact points
    Dual regulation of macrophage migration inhibitory factor (MIF) expression in hypoxia by CREB and HIF-1.

    John A Baugh, Michael Gantier, Lili Li, Aileen Byrne, Avril Buckley, Seamas C Donnelly

    Biochemical and biophysical research communications. 10/2006; 347(4):895-903.

    Macrophage migration inhibitory factor (MIF) is a well-described pro-inflammatory mediator that has also been implicated in the process of oncogenic transformation and tumor progression. However, despite the compelling evidence that MIF is overexpressed in, and contributes to, the pathology of infla... [more] Macrophage migration inhibitory factor (MIF) is a well-described pro-inflammatory mediator that has also been implicated in the process of oncogenic transformation and tumor progression. However, despite the compelling evidence that MIF is overexpressed in, and contributes to, the pathology of inflammatory and malignant diseases the mechanisms that contribute to exaggerated expression of MIF have been poorly described. Here we show that hypoxia, and specifically HIF-1alpha, is a potent and rapid inducer of MIF expression. In addition, we demonstrate that hypoxia-induced MIF expression is dependent upon a HRE in the 5'UTR of the MIF gene but is further modulated by CREB expression. We propose a model where hypoxia-induced MIF expression is driven by HIF-1 but amplified by hypoxia-induced degradation of CREB. Given the importance of MIF in inflammatory and malignant diseases these data reveal a HIF-1-mediated pathway as a potential therapeutic target for suppression of MIF expression in hypoxic tissues.
  • 10.69
    Impact points
    Cystic fibrosis, disease severity, and a macrophage migration inhibitory factor polymorphism.

    Barry J Plant, Charles G Gallagher, Richard Bucala, John A Baugh, Sally Chappell, Linda Morgan, Clare M O'Connor, Kevin Morgan, Seamas C Donnelly

    American journal of respiratory and critical care medicine. 01/2006; 172(11):1412-5.

    RATIONALE: Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. It contributes toward an exaggerated gram-negative inflammatory response via its ability to induce Toll-like receptor-4 expression. Studies have shown that MIF knockout mice have less aggressive Pseudomonas in... [more] RATIONALE: Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. It contributes toward an exaggerated gram-negative inflammatory response via its ability to induce Toll-like receptor-4 expression. Studies have shown that MIF knockout mice have less aggressive Pseudomonas infection (compared with wild-type). OBJECTIVES: To assess whether a novel functional MIF polymorphism was associated with clinical prognosis in a patient cohort with chronic gram-negative infection, namely cystic fibrosis (CF). METHODS: Collected genomic DNA was analyzed via polymerase chain reaction amplification for the polymorphic region for the CATT repeat polymorphism. Individuals may have a 5-, 6-, 7-, or 8-CATT tetranucleotide repeat unit on each allele. The 5-CATT repeat allele exhibits the lowest MIF promoter activity. MEASUREMENTS AND MAIN RESULTS: Patients with stable CF (n = 167) and a matched control group (n = 166) were enrolled. In patients with CF, the MIF5(+) group had a decreased incidence of Pseudomonas aeruginosa colonization (odds ratio, 0.25; 95% confidence interval, 0.09-0.65; p = 0.004) and a significant reduction in the risk of pancreatic insufficiency (odds ratio, 0.27; 95% confidence interval, 0.07-1.0; p = 0.05). A trend toward milder disease activity in the MIF5(+) group was seen with all other parameters. CONCLUSIONS: The results support the concept of a regulatory role for MIF in CF.
  • 14.51
    Impact points
    MIF signal transduction initiated by binding to CD74.

    Lin Leng, Christine N Metz, Yan Fang, Jing Xu, Seamas Donnelly, John Baugh, Thomas Delohery, Yibang Chen, Robert A Mitchell, Richard Bucala

    The Journal of experimental medicine. 07/2003; 197(11):1467-76.

    Macrophage migration inhibitory factor (MIF) accounts for one of the first cytokine activities to have been described, and it has emerged recently to be an important regulator of innate and adaptive immunity. MIF is an upstream activator of monocytes/macrophages, and it is centrally involved in the ... [more] Macrophage migration inhibitory factor (MIF) accounts for one of the first cytokine activities to have been described, and it has emerged recently to be an important regulator of innate and adaptive immunity. MIF is an upstream activator of monocytes/macrophages, and it is centrally involved in the pathogenesis of septic shock, arthritis, and other inflammatory conditions. The protein is encoded by a unique but highly conserved gene, and X-ray crystallography studies have shown MIF to define a new protein fold and structural superfamily. Although recent work has begun to illuminate the signal transduction pathways activated by MIF, the nature of its membrane receptor has not been known. Using expression cloning and functional analysis, we report herein that CD74, a Type II transmembrane protein, is a high-affinity binding protein for MIF. MIF binds to the extracellular domain of CD74, and CD74 is required for MIF-induced activation of the extracellular signal-regulated kinase-1/2 MAP kinase cascade, cell proliferation, and PGE2 production. A recombinant, soluble form of CD74 binds MIF with a dissociation constant of approximately 9 x 10-9 Kd, as defined by surface plasmon resonance (BIAcore analysis), and soluble CD74 inhibits MIF-mediated extracellular signal-regulated kinase activation in defined cell systems. These data provide a molecular basis for MIF's interaction with target cells and identify it as a natural ligand for CD74, which has been implicated previously in signaling and accessory functions for immune cell activation.
  • 3.52
    Impact points
    Macrophage migration inhibitory factor is associated with aneurysmal expansion.

    Jie-Hong Pan, Jes S Lindholt, Galina K Sukhova, John A Baugh, Eskild W Henneberg, Richard Bucala, Seamas C Donnelly, Peter Libby, Christine Metz, Guo-Ping Shi

    Journal of vascular surgery : official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter. 04/2003; 37(3):628-35.

    BACKGROUND: Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine released mainly from macrophages and activated lymphocytes. Both atherosclerosis and abdominal aortic aneurysm (AAA) are inflammatory diseases tightly linked to the function of these cells. The correlation and contr... [more] BACKGROUND: Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine released mainly from macrophages and activated lymphocytes. Both atherosclerosis and abdominal aortic aneurysm (AAA) are inflammatory diseases tightly linked to the function of these cells. The correlation and contribution of MIF to these human diseases remain unknown, although a recent rabbit study showed expression of this cytokine in atherosclerotic lesions. MATERIAL AND METHODS: MIF immunohistochemistry was performed on tissue sections from five normal aortas, seven atherosclerotic carotids, and six AAAs. A group of 112 men with small AAAs (defined as 3 to 5 cm) was recruited at the time of diagnosis, had serum samples taken, and was followed annually for 1 to 5 years (mean, 2.9 years) and referred for surgery if the AAA exceeded 5 cm in diameter. Of this study group, 98 had serum MIF measured with an enzyme-linked immunosorbent assay and 61 had detectable levels. RESULTS: In human atherosclerotic and aneurysmal lesions, MIF protein colocalized in macrophages, endothelial cells, and smooth muscle cells, but normal arteries had negligible MIF expression. Furthermore, serum-MIF levels correlated significantly with annual expansion rate (r = 0.28; P =.005), persisting after adjustment for initial AAA size, smoking habits, diastolic blood pressure, ankle blood pressure index, and age. After exclusion of 38 cases with MIF levels below the detection limit, initial AAA size was also significantly correlated with the MIF levels (r = 0.42; P =.001), persisting after adjustment for similar confounders, and the correlation coefficient with expansion rate increased to 0.42 (P =.001). CONCLUSION: Highly expressed MIF in macrophages, endothelial cells, and smooth muscle cells in lesions from atherosclerosis and AAA and significant association between serum MIF level and AAA initial size and AAA expansion rate in a group of patients with AAA suggest a potential involvement of this proinflammatory cytokine in the pathogenesis of these cardiovascular diseases.
  • 6.37
    Impact points
    Macrophage migration inhibitory factor.

    John Baugh, Richard Bucala

    Critical care medicine. 02/2002; 30(1 Supp):S27-S35.

    Macrophage migration inhibitory factor (MIF) has been proposed to be the physiologic counter-regulator of glucocorticoid action within the immune system. In this role, MIF's position within the cytokine cascade is to act in concert with glucocorticoids to control both the "set point" a... [more] Macrophage migration inhibitory factor (MIF) has been proposed to be the physiologic counter-regulator of glucocorticoid action within the immune system. In this role, MIF's position within the cytokine cascade is to act in concert with glucocorticoids to control both the "set point" and the magnitude of the inflammatory response. As well as overriding the immunosuppressive effects of glucocorticoids, it is now well established that MIF has a direct proinflammatory role in inflammatory diseases, such as sepsis, rheumatoid arthritis, and glomerulonephritis. The functions of MIF within the immune system are both unique and diverse, and although a unified molecular mechanism of action remains to be elucidated, there have been significant advances in our understanding of how MIF affects cellular processes. This review discusses the pathogenic role of MIF in inflammatory disease and highlights the novel structural, functional, and mechanistic properties of MIF.
  • 6.37
    Impact points
    Macrophage migration inhibitory factor.

    John A Baugh, Richard Bucala

    Critical care medicine. 02/2002; 30(1 Suppl):S27-35.

    Macrophage migration inhibitory factor (MIF) has been proposed to be the physiologic counter-regulator of glucocorticoid action within the immune system. In this role, MIF's position within the cytokine cascade is to act in concert with glucocorticoids to control both the "set point" a... [more] Macrophage migration inhibitory factor (MIF) has been proposed to be the physiologic counter-regulator of glucocorticoid action within the immune system. In this role, MIF's position within the cytokine cascade is to act in concert with glucocorticoids to control both the "set point" and the magnitude of the inflammatory response. As well as overriding the immunosuppressive effects of glucocorticoids, it is now well established that MIF has a direct proinflammatory role in inflammatory diseases, such as sepsis, rheumatoid arthritis, and glomerulonephritis. The functions of MIF within the immune system are both unique and diverse, and although a unified molecular mechanism of action remains to be elucidated, there have been significant advances in our understanding of how MIF affects cellular processes. This review discusses the pathogenic role of MIF in inflammatory disease and highlights the novel structural, functional, and mechanistic properties of MIF.

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