Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic, progressive fibrosing interstitial disease of unknown cause. It remains impractical to conduct early diagnosis and predict IPF progression just based on gene expression information. Moreover, the relationship between gene expression and quantitative phenotypic value in IPF keeps controversial. To identify biomarkers to predict survival in IPF, we profiled protein-coding gene expression in peripheral blood mononuclear cells (PBMCs). We linked the gene expression level with the quantitative phenotypic variation in IPF, including diffusing capacity of the lung for carbon monoxide (DLCO) and forced vital capacity (FVC) percent predicted. In silico analyses on the expression profiles and quantitative phenotypic data allowed for the generation of a set of IPF molecular signature that predicted survival of IPF effectively.
Sphingosine-1-phosphate lyase is an endogenous suppressor of pulmonary fibrosis: role of S1P signalling and autophagy.
Sex, Age, Disease, Race
View SamplesSarcoidosis, a systemic granulomatous syndrome invariably affecting the lung, typically spontaneously remits but in ~20% of cases progresses with severe lung dysfunction or cardiac and neurologic involvement (complicated sarcoidosis). Unfortunately, current biomarkers fail to distinguish patients with remitting (uncomplicated) sarcoidosis from other fibrotic lung disorders, and fail to identify individuals at risk for complicated sarcoidosis.
Peripheral blood gene expression as a novel genomic biomarker in complicated sarcoidosis.
Specimen part, Disease, Race
View SamplesLung transplantation remains the only viable treatment option for the majority of patients with advanced lung diseases. However, 5-year post-transplant survival rates remain low primarily secondary to chronic rejection. Novel insights from global gene expression profiles may provide molecular phenotypes and therapeutic targets to improve outcomes after lung transplantation. We compared whole-genome transcriptional expression profiled using the Affymetrix Human Exon Array in peripheral blood mononuclear cells (PBMCs) in lung transplant patients and normal individuals. 364 dysregulated genes in Caucasian lung transplant patients relative to normal individuals. Enriched Gene Ontology biological processes and pathways included defense response, immune response and response to wounding. We then compared the expression profiles of potential regulating miRNAs which suggested that dysregulation of a number of lung transplant-associated genes (e.g., ATR, FUT8, LRRC8B, NFKBIA) may be attributed to the differential expression of their regulating miRNAs. This exploratory analysis of the relationship between these miRNAs and their gene targets in the context of lung transplantation warrants further investigation and may serve as novel therapeutic targets in lung transplant complications.
MicroRNAs Implicated in Dysregulation of Gene Expression Following Human Lung Transplantation.
Sex, Specimen part, Treatment, Race
View SamplesPulmonary hypertension (PH) is a serious complication of sickle cell disease (SCD) associated with increased mortality. Gene expression profiles of peripheral blood mononuclear cells (PBMC) have been studied in pulmonary arterial hypertension and in SCD. We hypothesized that a PBMC-derived gene signature in SCD patients may be utilized as a PH biomarker. Twenty-seven patients with homozygous SCD underwent transthoracic echocardiography and PBMC isolation. PH was defined as estimated right ventricular systolic pressure (RVSP)>30 mmHg with a peak tricuspid regurgitation velocity (TRV)>2.5m/s. Genome-wide gene expression profiles were correlated against PH severity using RVSP and TRV as surrogates, which yielded 631 potentially dysregulated transcripts.
A novel molecular signature for elevated tricuspid regurgitation velocity in sickle cell disease.
Disease, Race
View SamplesClinically significant radiation-induced lung injury (RILI) is associated with significant morbidity and mortality and a common toxicity in patients administered thoracic radiotherapy. While the molecular etiology of RILI is poorly understood, we previously characterized a murine model of RILI in which alterations in lung endothelial barrier integrity surfaced as a potentially important pathobiologic event. In these studies, inhibition of HMG-CoA reductase activity (simvastatin) reduced murine RILI-associated lung inflammation and vascular leak and attenuated radiation-induced dysregulation of sphingolipid metabolic pathway genes identified by genome-wide lung gene expression profiling. In the present study, we test the hypothesis that sphingolipid signaling components serve as important modulators of RILI pathobiology and novel therapeutic targets. Sphingolipid involvement in murine RILI was confirmed by radiation-induced increases in lung expression of sphingosine kinase (SphK) isoforms 1 and 2 and increases in the ratio of ceramide to cumulative sphingosine-1-phosphate (S1P) and dihydro-S1P (DHS1P) levels in plasma, bronchoalveolar lavage (BAL) fluid and lung tissue following 25 Gy exposure (6 weeks). Moreover, genetically-engineered mice with either targeted deletion of SphK1 (SphK1-/-), or with reduced expression of selective members of the S1P receptor family (S1PR1+/-, S1PR2-/-, S1PR3-/-,), exhibited marked susceptibility to RILI-mediated lung inflammation. Finally, we assessed the efficacy of three potent vascular barrier-protective S1P analogues FTY720 (FTY), fTysiponate (fTyS) and SEW-2871 (SEW) in attenuating indices of RILI. The phosphonate analogue, fTyS, and to a lesser degree SEW, exhibited significant attenuation of RILI and RILI-induced gene dysregulation compared to control RILI-challenged mice (6 weeks). In contrast, FTY failed to significantly alter physiologic or genomic changes compared to RILI-challenged controls. Together, these results support the targeting of sphingolipid components as a novel and effective therapeutic strategy in RILI.
Role of sphingolipids in murine radiation-induced lung injury: protection by sphingosine 1-phosphate analogs.
Sex, Specimen part, Treatment
View SamplesStaphylococcus aureus pneumonia causes significant morbidity and mortality. Alpha-hemolysin (Hla), a pore-forming cytotoxin of S. aureus, has been identified through animal models of pneumonia as a critical virulence factor that induces lung injury. In spite of considerable molecular knowledge of how this cytotoxin injures the host, the precise host response to Hla in the context of infection remains poorly understood. We employed whole-genome expression profiling of infected lung to define the host response to wild-type S. aureus compared with an Hla-deficient isogenic mutant in experimental pneumonia. These data provide a complete expression profile at four and at twenty-four hours post-infection, revealing a unique response to the toxin-expressing strain. Gene ontogeny analysis revealed significant differences in the extracellular matrix and cardiomyopathy pathways, both of which govern cellular interactions in the tissue microenvironment. Evaluation of individual transcript responses to Hla-secreting bacteria was notable for upregulation of host cytokine and chemokine genes, including the p19 subunit of interleukin-23. Consistent with this observation, the cellular immune response to infection was characterized by a prominent TH17 response to wild-type staphylococci. These findings define specific host mRNA responses to Hla-producing S. aureus, coupling the pulmonary TH17 response to the presence of this cytotoxin. Expression profiling to define the host response to a single virulence factor proved to be a valuable tool in identifying pathways for further investigation in S. aureus pneumonia. This approach may be broadly applicable to the study of bacterial toxins, defining host pathways that can be targeted to mitigate toxin-induced disease.
Host response signature to Staphylococcus aureus alpha-hemolysin implicates pulmonary Th17 response.
Sex, Specimen part
View SamplesLung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes.
A sphingosine 1-phosphate 1 receptor agonist modulates brain death-induced neurogenic pulmonary injury.
Sex, Specimen part, Treatment
View SamplesSmooth muscle cells (SMCs) display dynamic plasticity by changing phenotype under various pathophysiological conditions. Uncovering how SMCs regulate their phenotype is a key to understanding the molecular mechanisms of a number of gastrointestinal diseases. MicroRNAs (miRNAs), generated in cells by Dicer, have been identified as regulators of the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal SMCs in a transgenic animal model. We generated SMC-specific Dicer (smDicer) null animals that express the reporter, green fluorescence protein (eGFP), in a SMC-specific manner. eGFP labeled SMCs were used for morphological, cytometric and genetic studies of smDicer null mutant and wild type control mice. The structure of the bowel wall was examined by confocal microscopy, and function was evaluated by recording spontaneous and evoked contractions. SMCs were purified with fluorescence-activated cell sorting and SM specific gene expression studies were performed with genechip arrays, PCR and quantitative PCR. Bioinformatic analyses were used to characterize the interaction between miRNAs and target genes. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs. Profiling and bioinformatic analyses showed SMC phenotype is regulated by a complex network of positive and negative feedback by SM miRNAs, serum response factor (SRF), and other transcriptional factors. SM miRNAs play an important role in growth, development and survival of SMCs. Phenotypic changes of SMCs may be regulated through multiple pathways in an interaction network of SM miRNAs, SRF, and additional transcriptional factors.
No associated publication
Age, Specimen part
View SamplesMost organisms have an endogenous circadian clock that is synchronized to environmental signals such as light and temperature. Although circadian rhythms have been described in the nematode C. elegans at the behavioral level, these rhythms appear to be relatively non-robust. Moreover, in contrast to other animal models, no circadian transcriptional rhythms have been identified. Thus, whether this simple nematode contains a bona fide circadian clock remains an open question.
Genome-wide analysis of light- and temperature-entrained circadian transcripts in Caenorhabditis elegans.
Specimen part, Time
View SamplesTo identify transcripts that are regulated by putative transcriptional co-activators, WT (Col) and KO of heat responsive transcriptional co-activator (Multiprotein Bridging Factor 1c) in Arabidopsis were subjeted to heat stress. These plants were compared to find transcripts that are regulated by the transcriptional co-activator during heat stress.
Identification of the MBF1 heat-response regulon of Arabidopsis thaliana
Age, Specimen part, Time
View Samples