Project description:Objective: Otitis media is known to alter expression of cytokine and other genes in the mouse middle ear and inner ear. However, whole mouse genome studies of gene expression in otitis media have not previously been undertaken. Ninety-nine percent of mouse genes are shared in the human, so these studies are relevant to the human condition. Methods: To assess inflammation-driven processes in the mouse ear, gene chip analyses were conducted on mice treated with trans-tympanic heat-killed Hemophilus influenza using untreated mice as controls. Middle and inner ear tissues were separately harvested at 6 hours, RNA extracted, and samples for each treatment processed on the Affymetrix 430 2.0 Gene Chip for expression of its 34,000 genes. Results: Statistical analysis of gene expression compared to control mice showed significant alteration of gene expression in 2,355 genes, 11% of the genes tested and 8% of the mouse genome. Significant middle and inner ear upregulation (fold change >1.5, p<0.05) was seen in 1,081 and 599 genes respectively. Significant middle and inner ear downregulation (fold change <0.67, p<0.05) was seen in 978 and 287 genes respectively. While otitis media is widely believed to be an exclusively middle ear process with little impact on the inner ear, the inner ear changes noted in this study were numerous and discrete from the middle ear responses. This suggests that the inner ear does indeed respond to otitis media and that its response is a distinctive process. Numerous new genes, previously not studied, are found to be affected by inflammation in the ear. Conclusion: Whole genome analysis via gene chip allows simultaneous examination of expression of hundreds of gene families influenced by inflammation in the middle ear. Discovery of new gene families affected by inflammation may lead to new approaches to the study and treatment of otitis media. There are 8 control samples and 9 samples trans-tympanically injected with H flu 10e9 for 6 hours. Each sample is from a single animal.
Project description:Objective: Otitis media is known to alter expression of cytokine and other genes in the mouse middle ear and inner ear. However, whole mouse genome studies of gene expression in otitis media have not previously been undertaken. Ninety-nine percent of mouse genes are shared in the human, so these studies are relevant to the human condition. Methods: To assess inflammation-driven processes in the mouse ear, gene chip analyses were conducted on mice treated with trans-tympanic heat-killed Hemophilus influenza using untreated mice as controls. Middle and inner ear tissues were separately harvested at 6 hours, RNA extracted, and samples for each treatment processed on the Affymetrix 430 2.0 Gene Chip for expression of its 34,000 genes. Results: Statistical analysis of gene expression compared to control mice showed significant alteration of gene expression in 2,355 genes, 11% of the genes tested and 8% of the mouse genome. Significant middle and inner ear upregulation (fold change >1.5, p<0.05) was seen in 1,081 and 599 genes respectively. Significant middle and inner ear downregulation (fold change <0.67, p<0.05) was seen in 978 and 287 genes respectively. While otitis media is widely believed to be an exclusively middle ear process with little impact on the inner ear, the inner ear changes noted in this study were numerous and discrete from the middle ear responses. This suggests that the inner ear does indeed respond to otitis media and that its response is a distinctive process. Numerous new genes, previously not studied, are found to be affected by inflammation in the ear. Conclusion: Whole genome analysis via gene chip allows simultaneous examination of expression of hundreds of gene families influenced by inflammation in the middle ear. Discovery of new gene families affected by inflammation may lead to new approaches to the study and treatment of otitis media. There are 6 control samples and 8 samples trans-tympanically injected with H flu 10e9 for 6 hours. Each sample is a pool of 4 animals
Project description:The spontaneous mutant Bronx waltzer (bv) mouse line is characterized by deafness and balance defect. We located the bv mutation to the Srrm4 gene which encodes a regulator of alternative pre-mRNA splicing. We found that Srrm4 is expressed in balance and hearing organs (i.e. in the vestibular maculas and the cochlea). Srrm4 is also expressed in the central nervous system including the cerebellum. To identify potential splicing defects in bv/bv mice, we analyzed RNA samples from the vestibular maculas and cerebellums of bv/bv mice and control (bv/+) littermates, using mouse exon junction microarrays (MJAY). In this dataset, we include probe-set level data obtained from vestibular macula samples. The processed data represent probe-set intensities that have been normalized to gene expression levels (Inorm). Inorm was calculated using batch-corrected data as well as data that were not corrected for a batch effect. 7 total samples were analyzed: vestibular maculas from 4 heterozygous (bv/+) and 3 homozygous (bv/bv) mouse embryos at E16.5.
Project description:To understand how GIPC3 exerts its effects on cuticular plate dimensions, we examined the GIPC3 protein-interaction network in hair cells. We immunoaffinity purified GIPC3 from crosslinked chicken inner ear extracts that were enriched for stereocilia, but still contain large amounts of hair-cell cytoplasmic proteins (Morgan et al., 2016). We carried out two separate experiments, each with ~1000 chicken ears, where we stabilized protein complexes using primary amine-reactive homo-bifunctional N-hydroxysuccimide ester crosslinkers that are thiol-cleavable and hence reversible (Mattson et al., 1993). In one experiment, we used dithiobis(succinimidyl propionate) (DSP), a membrane-permeable crosslinker that crosslinks extracellular and intracellular complexes; in the other experiment, we used 3,3'-dithiobis(sulfosuccinimidyl propionate) (DTSSP), which is membrane impermeant and thus only stabilizes extracellular and transmembrane complexes. We prepared soluble extracts of crude, crosslinked stereocilia and used these fractions for identifying GIPC3-interacting proteins.
Project description:Through its activity in stereocilia, MYO7A (myosin VIIA) is essential for hair cell function in the inner ear. Utilizing multiple stages of immunoaffinity enrichment, we have developed a strategy that allows us to partially purify stereocilia membranes from thousands of chick inner ears and isolate low-abundance MYO7A protein complexes from those membranes. By analysis of MYO7A and co-purifying molecules with shotgun and targeted mass spectrometry, we demonstrated that MYO7A forms a complex with PDZD7, a paralog of USH1C and DFNB31, which has been shown to localize to the ankle-link region of stereocilia.
Project description:Capping protein controls stereocilia length and width during hair bundle development. To determine what other proteins are involved in capping protein regulation, we carried out immunoaffinity purifications targeted at either CAPZA or CAPZB2. The starting material for immunopurification was crude stereocilia membranes isolated from mouse inner ear.
Project description:Allergic asthma is a complex trait. Several approaches have been used to identify biomarkers involved in this disease. This study aimed at demonstrating the relevance and validity of microarrays in the definition of allergic asthma expression pattern. The authors compared the transcript expressions of bronchial biopsy of 2 different microarray experiments done 2 years apart, both including nonallergic healthy and allergic asthmatic subjects (n = 4 in each experiment). U95Av2 and U133A GeneChips detected respectively 89 and 40 differentially expressed genes. Fifty-five percent of the U133A genes were previously identified with the U95Av2 arrays. The immune signaling molecules and the proteolytic enzymes were the most preserved categories between the 2 experiments, because 3/4 of the genes identified by the U133A were also significant in the U95Av2 study for both categories. These results demonstrate the relevance of microarray experiments using bronchial tissues in allergic asthma. The comparison of these GeneChip studies suggests that earlier microarray results are as relevant as actual ones to target new genes of interest, particularly in function categories linked to the studied disease. Moreover, it demonstrates that microarrays are a valuable technology to target novel allergic asthma pathways as well as biomarkers. 4 healthy controls without history of allergy and asthma and 4 allergic asthmatic subjects according to the American Thoracic Society (ATS) criteria were selected
Project description:We evaluated cutaneous contact hypersensitivity (CHS) in Cnr1-/-/Cnr2-/- animals using the obligate contact allergen 2,4-dinitrofluorobenzene (DNFB), which generates a specific cutaneous T-cell mediated allergic response upon repeated allergen contact. Allergic contact dermatitis affects about 5% of men and 11% of women in industrialized countries and is one of the leading causes for occupational diseases. In an animal model for cutaneous contact hypersensitivity we show that mice lacking both known cannabinoid receptors display exacerbated allergic inflammation. In contrast, fatty acid amide hydrolase deficient mice, which have increased levels of the endocannabinoid anandamide, displayed reduced allergic responses in the skin. Cannabinoid receptor antagonists exacerbated whereas receptor agonists attenuated allergic inflammation. These results demonstrate a protective role of the endocannabinoid system in contact allergy in the skin, and suggest a novel target for therapeutic intervention. Experiment Overall Design: Three wildtype mice (Wt) and three Cnr1-/-/Cnr2-/- (Ko) mice were used. Contact hypersensitivity was determined always at the right ears, which therefore were treated with DNFB (Tr). Left ears of mice were kept untreated and served as control ears (C). A total of 12 hybridizations were performed (2 strains x 2 treatments X 3 biological replicates) in this experiment.
Project description:Transcripts for GH, MHC Class I and II genes, and heavy- and light-chain myosins, as well as many others genes, were differentially regulated in the zebrafish inner ear following overexposure to sound. Following acoustic trauma in the zebrafish inner ear, we used microarray analysis to identify genes involved in inner ear repair following acoustic exposure by comparing the gene expression levels of 2 days and 4 days post-sound exposure (NE-ZF-2d and NE-ZF-4d, respectively) to controls without sound exposure (C-ZF).