youtube link for video https://www.youtube.com/watch?v=uEh9Dd3O7vs SCIENTIFIC INTEREST AREAS Recurrent vertigo is a common health problem caused by several disorders of the vestibular system in the inner ear. The most common causes are benign paroxysmal positional vertigo, vestibular migraine and Menière’s disease. Among them, Menière’s disease (MD) is the most severe form of vertigo and tinnitus. MD is a multifactorial chronic disorder in the inner ear causing sensorineural hearing loss, vertigo episodes and tinnitus with a prevalence of 75 cases/100.000 population in Spain. Familial Menière’s disease represents the 8-9% of the cases and it has a genetic heterogeneity with autosomal dominant, autosomal recessive and mitochondrial inheritance patterns. Our group has compiled the largest collection of human DNA samples from MD patients including 76 multicase families and > 1700 sporadic cases to identify the genes associated with Meniere’s disease. For this purpose we have genotyped sporadic cases and identified several loci in chromosome 6 associated with MD in noncoding regions. These signals are markers for autoimmune inner ear disease. Furthermore, we have performed whole exome sequencing (WES) in multicase families and we have defined de novel mutations for familial MD in FAM136A, PRKCB and DTNA genes in two families with autosomal dominant inheritance. Currently, we are assessing the functional role of these genes in a stem cell model with the variants of interest. RESEARCH AREAS ◦Line 1. Genomic architecture of sporadic Ménière's disease (MD). Our group has shown that allelic variants of genes of the innate immune response (MICA and TLR10) modify the outcome of the hearing loss in the disease. The goal of the proposed research is to identify modulating genes and biochemical pathways associated with sporadic MD. For this purpose we genotyped by a microarray with 186 loci associated with autoimmune diseases (Inmunochip) in a cohort of patients from Spain and we identified several loci in chromosome 6 in patients with bilateral sensorineural hearing loss. These signals point to new loci in regulatory regions that we will replicate in other groups of samples of European ancestry. This project is made in collaboration with the group of Marta Alarcón. ◦Line 2. Identification of novel mutations in familial Ménière’s disease Familial Menière’s disease represents the 8-9% of the cases and it has a genetic heterogeneity with autosomal dominant, autosomal recessive and mitochondrial inheritance patterns, being expected an interaction between multiple genes in each family, which would explain the incomplete penetrance or intermediate phenotypes. Bioinformatic analysis includes the selection of exclusive variants in the cases to identify candidate genes in each family and a biochemical-based pathway analysis to define groups of coding genes with candidate variants prioritized located in signaling pathways or biochemical common processes. Our group is sequencing > 15 multicase families and we expect to generate a list of 25-50 candidates genes to define the signaling pathways that determine the cochlear and vestibular phenotype of MD. We have identified novel mutations in DTNA, FAM136A and PRCKB genes. ◦Line 3. Molecular mechanisms in the autoimmune inner ear disease (AIED) The autoimmune inner ear disease is characterized by a bilateral sensorineural hearing loss with periods of exacerbation caused by a not well known allergic stimulus. This disease is characterized by an immune response in which pro-inflammatory cytokines such as TNFα and IL-1β are released. These cytokines can be released by macrophages or macrophage-like melanocytes of the cochlea that are located in the stria vascularis in the blood-fluid intraestrial barrier. Thus, AIED would develop by the existence of epitopes in environmental antigens with cross-reactivity with the inner ear proteins, because patients with AIED have an abnormal elevated level of IL-1β and the exposure to a fungus extract of mononuclear cells of these patients could produce an overexpression of IL-1β and IL-6. Menière’s disease can react to corticoids treatment, as well as AIED. Therefore, several studies have described partial audiometric improvements in 58-72% of cases with bilateral hearing loss and in 30% of cases with unilateral hearing loss. This response to steroids depends on the expression of the soluble form of type 2 IL-1 receptor (sIL1R2), which is a decoy receptor that binds to IL-1β irreversibly and inhibits the signal of IL-1β. ◦Our hypothesis is that a significant group of patients with MD have a genetic susceptibility determining an altered immune response and this subgroup would be part of AIED. The objective is to develop a diagnostic and prognostic tool to identify patients with AIED. ◦Line 4. Development of a cellular model in Meniere's disease The main goal of this project is to obtain induced pluripontent stem cells (iPSC) derived from mononuclear cells from individuals with familial MD with the mutations of interest, to prove the persistence of mutations in the iPSC. Subsequently, we want to generate otic progenitors to differentiate it into hair cells, auditory and vestibular neurons and epithelial cells with secretory activity. This project is carried out in collaboration with the group of Pedro Real. ◦Line 5. Molecular basis of tinnitus in Meniere's disease Hyperacusis and tinnitus are constant symptoms in MD. Hypersensitivity and tinnitus poor tolerance reflect a altered brain excitability. The goal of the proposed research is to identify which individuals have a tinnitus problem and to develop a neuronal cell model from iPSC to define the molecular basis of abnormal neuronal excitability. Our group will select individuals with an extreme phenotype (MD with hyperacusis and unilateral tinnitus persistent without treatment and THI> percentile 90) to undertake a WES study to identify the responsible genes.