Meniere’s disease is a set of rare disorders of the inner ear defined by sensorineural hearing loss, episodic vertigo and roaring tinnitus. It is a debilitating condition of unknown etiology, where a personalised medicine approach is needed.
Most Meniere’s disease patients are considered sporadic, and 20 per cent of patients show an abnormal immune response with persistent levels of pro-inflammatory cytokines (IL1ß, TNFa, IL-6), leading to a systemic chronic inflammation. The trigger of this pro-inflammatory reaction is not known and it has been related with allergy, viral or bacterial infections.
Other subgroups of Meniere’s disease patients have migraine or an autoimmune disorder, including autoimmune thyroid disease or rheumatoid arthritis which require a multi-disciplinary approach to control the symptoms.
Familial Meniere’s disease is around 8-9 per cent in European descendent population and it may show autosomal dominant of recessive inheritance. By exome sequencing, we have identified rare variants in several genes including OTOG, MYO7A, TECTA in familial Meniere’s disease. These findings support the hypothesis that the interaction between hair cells stereocilia and the tectorial membrane in the organ of Corti or the otolithic membrane in the saccule play a central role in the pathogenesis of the disease. We plan to perform functional validation studies of these variants in cellular and animal models.
Chronic tinnitus is a common condition in Meniere’s disease patients and severe tinnitus is found in 1 per cent of the population. Tinnitus is considered a disorder when the condition is associated with sensorineural hearing loss, hyperacusis, anxiety and depression.
Professor of Meniere disease Neuroscience
Faculty of Medicine and Health, School of Medical Sciences
The Kolling Institute, University of Sydney
Postdoctoral Research Associate
Research Assistant
Research Fellow
Postdoctoral Research Associate
Tanvi Hussain - Master Student
Jacob Pogson - Senior Audiologist
Tom Comford - Honours Student
Pablo Cruz Granados - PhD Student
Sayedali Mohseni - Masters Student (Data Science Intern)
Anvitha Peddada - Masters Student (Data Science Intern)
Maniratnam (Mani) Meka - - Masters Student (Data Science Intern)
Sreeparna Das - Honours Student
Giselle Bianco Bortoletto - Visiting Student
Kiana Bagheri Lotfabad - IT Research Associate – Digital Health
Current projects:
Deciphering the genetics and inflammatory bases of Meniere’s disease and Tinnitus Disorder by combining multi-omic data and 3D cellular models.
Meniere's disease is the third most common cause of episodic vertigo after benign paroxysmal positional vertigo and vestibular migraine in neurotology clinics. It is considered a rare and debilitating disease within the general population.
It is a multifactorial inner ear disorder characterized by episodes of spontaneous vertigo, associated with tinnitus, and fluctuating sensorineural hearing loss. It is a heterogeneous condition with a variable phenotype associated with other comorbidities such as migraine, several autoimmune and autoinflammatory disorders, including allergies.
According to epidemiological and genetic data, the condition has a significant genetic contribution. Familial MD is observed in 6-10% of cases and rare mutations in OTOG, MYO7A and TECTA genes have been found in several unrelated families. Although most patients are considered sporadic, hidden recessive inheritance and de novo mutations are emerging as causative in Meniere's Disease, and genetic diagnosis is being implemented.
Genetic modelling of Meniere disease
We have established an auditory and vestibular phenotyping laboratory at the Kolling Institute. We are working with a preclinical model to assess the functional role of human mutations found in Spanish families with Meniere disease, including OTOG-mediated compound recessive inheritance and MYO7A-mediated loss of function Meniere disease.
Understanding the immune response in Meniere disease
Patients with Meniere's disease show a persistent systemic inflammatory status, proinflammatory cytokines released by monocytes (IL-1β and TNF-α), and high levels of CCL2, IL-4, and IgE, support a disorder in the immune response with several immunophenotypes. Some patients with an autoinflammatory phenotype mediated by IL-1β, while others show an autoimmune profile driven byTNF-α and usually associated with autoimmune thyroid disease or systemic rheumatoid disorders. Moreover, a relevant group of individuals have a persistent type 2 immune response with IL-4, IL-13, and IL-6 with high levels of IgE. By combining single cell transcriptomics and proteomics, we are starting to define the molecular signals driving each immunophenotype.
Therefore, genetic factors and innate/adaptive immune responses play a central role in the pathophysiology of the condition.
Tinnitus is the perception of a phantom sound that affects between 10 and 15% of the general population. Furthermore, 1–3% of the population can be diagnosed with a debilitating tinnitus disorder, a condition associated with sleep disturbance and psychological distress, with emotional and behavioral consequences with a significant impact on health-related quality of life.
Despite this high burden for the health system, treatments for tinnitus are presently lacking since the heterogeneity of the tinnitus patients represents a major barrier to the development of effective tinnitus therapies. Tinnitus is not only a symptom associated with hearing loss, but it is also considered the result of exacerbated plasticity of the central auditory system in response to the crosstalk with auditory nerve fibers.
The development of tinnitus is related to different nuclei of the auditory pathway, particularly the cochlear nuclei and the primary auditory cortex. The perception of tinnitus involves different brain areas and neural networks in which other structures such as the hippocampus or prefrontal cortex. Likewise, it can involve unknown auditory and non-auditory networks and molecular pathways. This complex combination has hampered advancements in the field and the identification of a genetic contribution to tinnitus has been at the forefront of tinnitus research in the last five years.
Potential PhD projects
1. Identification and validation of novel genes in Meniere disease by comprehensive analysis of coding and non-coding regions in the human genome.
2. Role of mobile elements in the genetic architecture of Meniere disease and tinnitus disorder
3. Audiovestibular phenotyping of a transgenic OTOG mouse model of Meniere disease
4. Single cell multiome analysis of immune response in Meniere disease patients
5. Tonotopic epigenetic profiling in the mouse cochlea
6. Genetic and epigenetic biomarkers of severe tinnitus
The Meniere’s Disease Neuroscience Program is an initiative of the University of Sydney to investigate the cellular and molecular bases of this condition and to identify molecular targets to develop personalised treatments.
Our laboratory is located at the Kolling Institute, level 11, and will join the expertise of the Otology and Neurotology Group at the University of Granada with the added value of new laboratory members to develop an ambitious international multidisciplinary research program. The team will combine clinical and human multi-omic data (genomic, epigenomic, transcriptomics) and cellular and animal models to reveal the molecular mechanisms leading to Meniere's Disease and severe tinnitus.
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