Villar J.,CIBER ISCIII |
Villar J.,A+ Network |
Villar J.,Li Ka Shing Knowledge Institute |
Cabrera N.,CIBER ISCIII |
And 13 more authors.
Intensive Care Medicine
Background: Experimental and clinical studies on sepsis have demonstrated activation of the innate immune response following the initial host-bacterial interaction. In addition, mechanical ventilation (MV) can induce a pulmonary inflammatory response. How these two responses interact when present simultaneously remains to be elucidated. We hypothesized that MV modulates innate host response during sepsis by influencing Toll-like receptor (TLR) signaling. Design: Prospective, randomized, controlled animal study. Subjects: Male, septic Sprague- Dawley rats. Interventions: Sepsis was induced by cecal ligation and perforation. At 18 h, surviving animals had the cecum removed and were randomized to spontaneous breathing or two strategies of MV for 4 h: high (20 ml/kg) tidal volume (VT) with no positive end-expiratory pressure (PEEP) versus low VT (6 ml/kg) plus 10 cmH2O PEEP. Measurements and main results: Histological evaluation, TLR-2, TLR-4, inhibitory kappaB alpha (IκBα), interleukin-1 receptorassociated kinase-3 (IRAK-3) gene expression, protein levels and immunohistochemical lung localization, inflammatory cytokines gene expression, and protein serum concentrations were analyzed. MV with low VT plus PEEP attenuated sepsis-associated TLR-4 activation, and produced a signifi-cant decrease of IRAK-3 gene expression and protein levels, a significant increase of IjBa, and a decrease in lung gene expression and serum levels of cytokines. High-VT MV caused a significant increase of TLR-4 and IRAK-3 protein levels, lung and systemic cytokines,and mortality, and a significant decrease of IκBα. Conclusions: Our findings suggest a novel mechanism that could partially explain how MV modulates the innate immune response in the lung by interfering with cellular signaling pathways that are activated in response to pathogens. © 2010 jointly held by Springer and ESICM. Source
Flores C.,CIBER ISCIII |
Flores C.,Hospital Universitario Ns Of Candelaria |
Ma S.-F.,University of Chicago |
Pino-Yanes M.,CIBER ISCIII |
And 8 more authors.
Background: Asthma is a common complex condition with clear racial and ethnic differences in both prevalence and severity. Asthma consultation rates, mortality, and severe symptoms are greatly increased in African descent populations of developed countries. African ancestry has been associated with asthma, total serum IgE and lower pulmonary function in African-admixed populations. To replicate previous findings, here we aimed to examine whether African ancestry was associated with asthma susceptibility in African Americans. In addition, we examined for the first time whether African ancestry was associated with asthma exacerbations. Methodology/Principal Findings: After filtering for self-reported ancestry and genotype data quality, samples from 1,117 self-reported African-American individuals from New York and Baltimore (394 cases, 481 controls), and Chicago (321 cases followed for asthma exacerbations) were analyzed. Genetic ancestry was estimated based on ancestry informative markers (AIMs) selected for being highly divergent among European and West African populations (95 AIMs for New York and Baltimore, and 66 independent AIMs for Chicago). Among case-control samples, the mean African ancestry was significantly higher in asthmatics than in non-asthmatics (82.0±14.0% vs. 77.8±18.1%, mean difference 4.2% [95% confidence interval (CI):2.0-6.4], p<0.0001). This association remained significant after adjusting for potential confounders (odds ratio: 4.55, 95% CI: 1.69-12.29, p = 0.003). African ancestry failed to show an association with asthma exacerbations (p = 0.965) using a model based on longitudinal data of the number of exacerbations followed over 1.5 years. Conclusions/Significance: These data replicate previous findings indicating that African ancestry constitutes a risk factor for asthma and suggest that elevated asthma rates in African Americans can be partially attributed to African genetic ancestry. © 2012 Flores et al. Source
Shah C.V.,University of Pennsylvania |
Lanken P.N.,University of Pennsylvania |
Localio A.R.,University of Pennsylvania |
Gallop R.,West Chester University |
And 9 more authors.
Background: In observational studies using acute lung injury (ALI) as an outcome, a spectrum of lung injury and difficult-to-interpret chest radiographs (CXRs) may hamper efforts to uncover risk factor associations. We assessed the impact of excluding patients with difficult-to-classify or equivocal ALI diagnosis on clinical and genetic risk factor associations for ALI after trauma. Methods: This study was of a prospective cohort of 280 critically ill trauma patients. The primary outcome was the development of ALI. Patients were classified into one of three groups:(1) definite ALI (patients who fulfilled the American-European Consensus Conference [AECC] criteria for ALI), (2) equivocal ALI (patients who had difficult-to-interpret CXRs), and (3) definite non-ALI. We compared clinical and genetic ALI risk factor associations between two classification schemes: AECC classification (definite ALI vs rest) and alternative classification (definite ALI vs definite non-ALI, excluding equivocal ALI). Results: Ninety-three (35%) patients were classified as definite ALI, 67 (25%) as equivocal, and 104 (39%) as definite non-ALI. Estimates of clinical and genetic ALI risk factor associations were farther from the null using the alternative classification. In a multivariable risk factor model, the C statistic of the alternative classification was significantly higher than that derived from the AECC classification (0.82 vs 0.74; P < .01). Conclusions: The ability to detect ALI risk factors may be improved by excluding patients with equivocal or difficult-to-classify ALI. Such analyses may provide improved ability to detect clinical and genetic risk factor associations in future epidemiologic studies of ALI. © 2010 American College of Chest Physicians. Source
Han Y.J.,University of Chicago |
Ma S.-F.,University of Chicago |
Wade M.S.,University of Illinois at Chicago |
Flores C.,CIBER ISCIII |
And 2 more authors.
Journal of Molecular Medicine
Intronic single-nucleotide polymorphisms (SNPs) are commonly associated with complex diseases but exhibit unknown biologic functionality. Myosin lightchain kinase (MLCK), a central cytoskeletal regulator encoded by MYLK, plays a key pathophysiological role in complex diseases including acute lung injury (ALI) and asthma. We studied the potential regulatory roles of two intronic MYLK SNPs (rs936170 and rs820336) previously associated with ALI and asthma. Due to their genomic location at the junction encoding the non-muscle and smooth muscle MLCK (smMLCK) isoforms, we first identified the transcription start site (TSS) of the smMLCK isoform, and isolated a 2,954-bp DNA fragment upstream of the smMLCK TSS. Serial 5? deletion of the fragment revealed a proximal promoter region exhibiting strong promoter activity with potential inhibitory elements in the distal region. Site-directed mutageneses and luciferase reporter assays showed no effect of the distal promoter SNP rs936170 on smMLCK promoter activity. In contrast, SNP rs820336, located in an enhancer/repressor region downstream of TSS, was identified to regulate smMLCK promoter activity in an allelic-dependent manner. The A allele interrupted the binding site for Forkhead box protein N1 (FOXN1), a transcription factor governing expression of immune response genes. Silencing of FOXN1 expression (siRNA) reduced FOXN1 interaction with cis-regulatory elements in proximity to rs820336 and significantly decreased smMLCK expression. These functional insights into the involvement of intronic MYLK SNPs further strengthen the concept that MYLK contributes to inflammatory disease susceptibility and represents an attractive molecular target in complex inflammatory disorders. © Springer-Verlag 2012. Source
Quilez M.E.,CIBER ISCIII |
Quilez M.E.,Institute Universitari |
Fuster G.,CIBER ISCIII |
Fuster G.,Institute Universitari |
And 11 more authors.
Introduction: Survivors of critical illness often have significant long-term brain dysfunction, and routine clinical procedures like mechanical ventilation (MV) may affect long-term brain outcome. We aimed to investigate the effect of the increase of tidal volume (Vt) on brain activation in a rat model.Methods: Male Sprague Dawley rats were randomized to three groups: 1) Basal: anesthetized unventilated animals, 2) low Vt (LVt): MV for three hours with Vt 8 ml/kg and zero positive end-expiratory pressure (ZEEP), and 3) high Vt (HVt) MV for three hours with Vt 30 ml/kg and ZEEP. We measured lung mechanics, mean arterial pressure (MAP), arterial blood gases, and plasma and lung levels of cytokines. We used immunohistochemistry to examine c-fos as a marker of neuronal activation. An additional group of spontaneously breathing rats was added to discriminate the effect of surgical procedure and anesthesia in the brain.Results: After three hours on LVt, PaO2decreased and PaCO2increased significantly. MAP and compliance remained stable in MV groups. Systemic and pulmonary inflammation was higher in MV rats than in unventilated rats. Plasma TNFα was significantly higher in HVt than in LVt. Immunopositive cells to c-fos in the retrosplenial cortex and thalamus increased significantly in HVt rats but not in LVt or unventilated rats.Conclusions: MV promoted brain activation. The intensity of the response was higher in HVt animals, suggesting an iatrogenic effect of MV on the brain. These findings suggest that this novel cross-talking mechanism between the lung and the brain should be explored in patients undergoing MV. © 2011 Quilez et al.; licensee BioMed Central Ltd. Source