ABSTRACT: The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
ORGANISM(S): Mus musculus Homo sapiens Gallus gallus
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola. To identify genes that are co-expressed with GATA3 at the striola reversal zone, we compared gene expression in cells micro-dissected from the sensory epithelia of the chick utricle striola to cells from the surrounding extra-striola. There are 2 biological samples and experiments include technical replicates as well as dye-switches for a total of 8 microarrays.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola. Whole utricle specimens were treated with streptomycin for 24 hrs, rinsed and allowed to recover for an additional 24 hrs. Whole utricles were transfected with either GATA3 or GFP 21mer synthetic siRNAs for an additional 48 hrs and pure sensory epithelia were isolated. There are 2 biological samples and experiments include technical replicates as well as dye-switches for a total of 8 microarrays.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these hair cells lack the capacity for regeneration. Unlike mammals, hair cells from non-mammalian vertebrates, such as birds, can be regenerated throughout the life of the organism making them a useful model for studying inner ear genetics pathways. The zinc finger transcription factor GATA3 is required for inner ear development and mutations cause sensory neural deafness in humans. In the avian cochlea GATA3 is expressed throughout the sensory epithelia; however, expression is limited to the striola of the utricle. The striola corresponds to an abrupt change in morphologically distinct hair cell types and a 180° shift in hair cell orientation. We used 3 complimentary approaches to identify potential downstream targets of GATA3 in the avian utricle. Specifically we used microarray expression profiling of GATA3 knockdown by siRNA and GATA3 over-expression treatments as well as direct comparisons of GATA3 expressing cells from the striola and non GATA3 expressing cells from the extra-striola. Dissociated sensory epithelia were plated in 96 well cultures, 5 wells per sample. 4 days post plating, ~ 30% confluency, cells were transfected with a pMES vector containing an internal ribosome entry site regulating expression of GATA3 and eGFP under control of a chick beta-actin promoter. Controls were transfected with a vector containing EGFP only. There are 2 biological samples and experiments include technical replicates as well as dye-switches for a total of 8 microarrays.
Project description:The avian utricle, a vestibular organ of the inner ear, displays turnover of sensory hair cells throughout life. This is in sharp contrast to the mammalian utricle, which shows limited regenerative capacity. Here, we use single-cell RNA-sequencing to identify distinct marker genes for the different sensory hair cell subtypes of the chicken utricle, which we validated in situ . We provide markers for spatially distinct supporting cell populations, and identified two transitional cell populations of dedifferentiating supporting cells and developing hair cells. Trajectory reconstruction resulted in an inventory of gene expression dynamics of natural hair cell generation in the avian utricle.
Project description:In adult mammals, hair cell loss is irreversible and may result in hearing and balance deficits. In contrast, birds can regenerate hair cells through differentiation of supporting cells and restore inner ear function, suggesting that hair cell progenitors are present in the population of supporting cells. We used microarrays to identify novel genes related to the regeneration in the chicken utricle. Supporting cell and hair cell populations of chicken utricle obtained by laser capture microdissection, following to do RNA extraction and hybridization on Affymetrix microarrays.
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these sensory hair cells lack the capacity for regeneration and if damaged lead to hearing or balance disorders. However, non-mammalian vertebrates such as birds maintain their regenerative abilities throughout their life. In a previous study we conducted a gene expression profiling time course of regenerating sensory epithelia (SE) in avian cochlea and utricle on a custom transcription factor microarray following damage by both laser and chemical ablation. We identified several known signaling cascades such as The Pax-Eya-Six-Dach pathway, Ap-1 pathway, the Tgf-β pathway and sonic hedgehog signaling that are differentially expressed during SE regeneration. In this study we selected 27 of these genes for knockdown by siRNA or small molecule inhibition to determine their requirement for SE regeneration and identify downstream targets. We assessed phenotypes using a 96 well proliferation assay and expression profiled each knockdown on a custom transcription factor microarray. Using these techniques we have determined several genes that are required for SE proliferation and identified novel epistatic relationships between many of these genes. Pure sensory epithelia was isolated from avian utricles. Sensory epithelia was physically dissociated and grown in 96 well cultures for 3 days. Prior to confluency, dissociated sensory epithelia were transfected with siRNAs (12 pmol/well) or small molecule inhibitor in 0.1% DMSO. RNA was isolated 24 hrs post transfection and assayed on a custom oligonucleotide transcription factor microarray compared to controls (GFP siRNA or 0.1% DMSO only). siRNA: CEBPG, JunD, BTAF1, LRP5, PAX2, PAX5, PAX7, Wnt4, BCL11A, CBX3, CBX4, CTNNB1, CUTL1, MYT1L, RARA, TIMELESS, TRIP15, PAX3, EZH2, HES1, ID1, CDKN1B, and PPARGC1 small molecule inhibition: IGF, MAPK, SHH, and JNK
Project description:The inner ear utilizes sensory hair cells as mechano-electric transducers for sensing sound and balance. In mammals, these sensory hair cells lack the capacity for regeneration and if damaged lead to hearing or balance disorders. However, non-mammalian vertebrates such as birds maintain their regenerative abilities throughout their life. In a previous study we conducted a gene expression profiling time course of regenerating sensory epithelia (SE) in avian cochlea and utricle on a custom transcription factor microarray following damage by both laser and chemical ablation. We identified several known signaling cascades such as The Pax-Eya-Six-Dach pathway, Ap-1 pathway, the Tgf-β pathway and sonic hedgehog signaling that are differentially expressed during SE regeneration. In this study we selected 27 of these genes for knockdown by siRNA or small molecule inhibition to determine their requirement for SE regeneration and identify downstream targets. We assessed phenotypes using a 96 well proliferation assay and expression profiled each knockdown on a custom transcription factor microarray. Using these techniques we have determined several genes that are required for SE proliferation and identified novel epistatic relationships between many of these genes.
Project description:In adult mammals, hair cell loss is irreversible and may result in hearing and balance deficits. In contrast, birds can regenerate hair cells through differentiation of supporting cells and restore inner ear function, suggesting that hair cell progenitors are present in the population of supporting cells. We used microarrays to identify novel genes related to the regeneration in the chicken utricle.