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.
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.
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:Influenza A virus (IAV) predisposes individuals to secondary infections with the bacterium Streptococcus pneumoniae (the pneumococcus). Infections may manifest as pneumonia, sepsis, meningitis or otitis media (OM). It remains controversial as to whether secondary pneumococcal disease is due to the induction of an aberrant immune response or IAV induced immunosuppression. Moreover, as the majority of studies have been performed in the context of pneumococcal pneumonia, it remains unclear how far these findings can be extrapolated to other pneumococcal disease phenotypes. Here, we demonstrate that the viral hemagglutinin (HA) mediates bacterial OM by inducing a pro-inflammatory response in the middle ear cavity in a replication-dependent manner. Importantly, our findings show that it is the inflammatory response that mediates pneumococcal replication; not viral suppression of the immune system or epithelial damage. This study provide the first evidence that HA induced inflammation drives pneumococcal replication in the middle ear cavity, which has important consequences to the treatment of pneumococcal OM.
Project description:* Bone signaling in middle ear development * <br/>Common middle ear diseases, such as chronic suppurative otitis media and cholesteatoma, may affect bone behavior in the middle ear air cell system. <br/> This study analyzed gene expression of bone-related signaling factors and gene sets from lining tissues in the developing middle ear of the rat. Candidate gene products were compared with previously published data on middle ear bone metabolism. <br/> Microarray technology was used to identify bone-related genes and gene sets, which were differentially expressed between the adult (quiescent) bulla and young (resorbing/forming) bulla. <br/><br/> * Gene expression of the otic capsule *<br/>The behavior of bone cells within the otic capsule is unique. After occification localized bone remodeling is virtually absent. Human otosclerosis is a localized disease within the otic capsule where the bone starts to remodel pathologically. Disease etiology is unknown and the pathogenesis is only partially elucidated.<br/><br/> The objective of this study is to measure bone-related gene expression of the otic capsule in order to reveal additionally signaling factors responsible for the absent bone remodeling within the otic capsule.<br/><br/> Microarray technology was used to determine genes involved in the bone metabolism, which were differentially expressed between lining tissues from the otic capsule and lining tissues from the middle ear of the rat.
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.
Project description:Middle ear epithelium (MEE) is an extended part of the respiratory mucosa and mucociliary differentiation of MEE is crucial for the maintenance of homeostasis and sterility of the middle ear cavity. Previously we developed an in vitro model of murine MEE using air-liquid interface (ALI) culture that replicates aspects of the in vivo middle ear. Defects in MEE function can lead to the development of otitis media (OM). Decoding differential gene expression (DGE) across the MEE during mucociliary differentiation is valuable in understanding the mechanism underpinning the development of OM. We used ClariomTM S Mouse assay to understand the global gene expression at different time points of murine MEE differentiation at ALI culture and to identify sets of genes up-regulated and down-regulated during this process.
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. Weekly transtympanic inoculation of Balb/c mice with 300 µg/ml of NTHi lysates vs saline was performed. Bacteria were grown on chocolate agar at 37ºC in 5% CO2 overnight and inoculated in brain heart infusion (BHI) broth supplemented with 3.5 mg of nicotinamide adenine dinucleotide per ml. After overnight incubation, bacteria were subcultured into 5 ml of fresh brain heart infusion (BHI) and upon reaching log phase growth, NTHi were washed and suspended in phosphate-buffered saline (PBS) followed by sonication for lysis. Three transtympanic inoculation of 6 Balb/c mice middle ears (3 animals, 6 ears) with 50 uL of 300 ug/ml of NTHi bacterial lysate and 6 Balb/c mice middle ears (3 animals, 6 ears) with 50 uL of 1X phosphate buffered saline (PBS) were carried out weekly over 4 weeks (injection on days 7, 14, and 21). On day 28, the mice were euthanized and their bullae harvested. Expression microarray analysis was performed at 1 and 7 days. Microarray findings were validated in independent animal samples and in a cultured murine middle ear epithelial cell (mMEEC) line.