Project description:Chronic otitis media with effusion (COME) is the most common cause of childhood hearing loss in the developed world. Underlying pathophysiology is not well understood, and in particular the factors that lead to the transition from acute to chronic inflammation. Here we present the first genome-wide transcript analysis of white blood cells in the effusion of children with COME. Analysis of microarray data for enriched pathways reveals upregulation of hypoxia pathways, which is confirmed using real-time PCR and determining VEGF protein titres. Other pathways upregulated in both mucoid and serous effusions include Toll-like receptor signalling, complement, and RANK-RANKL. Transcript analysis indicates serous fluids have CD4+ and CD8+ T-lymphocyte, and NK cell signatures. Overall, our findings suggest that inflammation and hypoxia pathways are important in the pathology of COME and targets for potential therapeutic intervention, and that mucoid and serous COME may represent different immunological responses.
Project description:Nontypeable Haemophilus influenzae (NTHi) is a common causative organism of acute otitis media (AOM) in children. A human cDNA microarray comprising 30,968 human genome probes was used to evaluate the transcriptional changes that occur in peripheral blood mononuclear cells (PBMC) at the onset of clinical AOM caused by NTHi infection in children after comparison of microarray results with the pre-infection healthy stage of the same children. Four to ten milliliters of heparinized peripheral venous blood was collected from children at 6 to 30 months of age when they were in acute otitis media (AOM) stage and pre-infection healthy stage. The diagnosis of AOM was based on symptoms and signs as well as Nontypeable Haemophilus influenzae culture positive in the middle ear fluid. Patients with polymicrobial infections, history of immunodeficiency, history of chronic or recurrent AOM, chronic disease, or receiving steroids or other immunomodulatory agents were excluded. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll gradient and total RNA was extracted from PBMCs using the QIAamp RNA blood Mini Kit (Qiagen, Maryland, USA) according to manufacturerM-bM-^@M-^Ys instructions. Double-stranded cDNA generated from total RNA was labeled with Cyanine-5 and subsequently hybridized to Human OneArray glass slides according to the manufacturer's standard protocols (PhalanxBio Inc, CA, USA). Microarrays were scanned at 5 M-NM-<m resolution using an Agilent scanner. Raw intensity signals for each microarray were captured using a Molecular Dynamics Axon 4100A scanner, measured using GenePixProM-bM-^DM-" Software. The data from all microarrays in each experimental set was then analyzed using Omicsoft Array Studio software; control and missing features were removed, and the remaining signals were quantile normalized.
Project description:Streptococcus pneumoniae (Spn) is the predominant causative organism of acute otitis media (AOM) in children. A human cDNA microarray comprising 30,968 human genome probes was used to evaluate the transcriptional changes that occur in peripheral blood mononuclear cells (PBMC) at the onset of clinical AOM caused by Spn infection in children after comparison of microarray results with the pre-infection healthy stage of the same children. Four to ten milliliters of heparinized peripheral venous blood was collected from children at 6 to 30 months of age when they were in acute otitis media (AOM) stage and pre-infection healthy stage. The diagnosis of AOM was based on symptoms and signs as well as S. pneumoniae culture positive in the middle ear fluid. Patients with polymicrobial infections, history of immunodeficiency, history of chronic or recurrent AOM, chronic disease, or receiving steroids or other immunomodulatory agents were excluded. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll gradient and total RNA was extracted from PBMCs using the QIAamp RNA blood Mini Kit (Qiagen, Maryland, USA) according to manufacturer’s instructions. Double-stranded cDNA generated from total RNA was labeled with Cyanine-5 and subsequently hybridized to Human OneArray glass slides according to the manufacturer's standard protocols (PhalanxBio Inc, CA, USA). Microarrays were scanned at 5 μm resolution using an Agilent scanner. Raw intensity signals for each microarray were captured using a Molecular Dynamics Axon 4100A scanner, measured using GenePixPro™ Software. The data from all microarrays in each experimental set was then analyzed using Omicsoft Array Studio software; control and missing features were removed, and the remaining signals were quantile normalized.
Project description:Chronic Otitis Media (OM) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Non-typeable Haemophilus influenzae (NTHi), the most common acute OM pathogen, is known to activate inflammation and mucin expression in vitro and in animal models of OM. The goals of this study were to: examine expression profiling epithelial effects of NTHi challenge in murine middle ears. We used microarrays to detail examine the global programme of gene expression underlying epithelial effects of NTHi challenge in murine middle ears during this study.