Biomarkers for Inner Ear Disorders: Scoping Review on the Role of Biomarkers in Hearing and Balance Disorders

Abstract

The diagnostics of inner ear diseases are primarily functional, but there is a growing interest in inner ear biomarkers. The present scoping review aimed to elucidate gaps in the literature regarding the definition, classification system, and an overview of the potential uses of inner ear biomarkers. Relevant biomarkers were categorized, and their possible benefits were evaluated. The databases OVID Medline, EMBASE, EBSCO COINAHL, CA PLUS, WOS BIOSIS, WOS Core Collection, Proquest Dissertations, Theses Global, PROSPERO, Cochrane Library, and BASE were searched using the keywords “biomarker” and “inner ear”. Of the initially identified 1502 studies, 34 met the inclusion criteria. The identified biomarkers were classified into diagnostic, prognostic, therapeutic, and pathognomonic; many were detected only in the inner ear or temporal bone. The inner-ear-specific biomarkers detected in peripheral blood included otolin-1, prestin, and matrilin-1. Various serum antibodies correlated with inner ear diseases (e.g., anti-type II collagen, antinuclear antibodies, antibodies against cytomegalovirus). Further studies are advised to elucidate the clinical significance and diagnostic or prognostic usage of peripheral biomarkers for inner ear disorders, filling in the literature gaps with biomarkers pertinent to the otology clinical practice and integrating functional and molecular biomarkers. These may be the building blocks toward a well-structured guideline for diagnosing and managing some audio-vestibular disorders.

Identification of a Thyroid Hormone Binding Site in Hsp90 with Implications for Its Interaction with Thyroid Hormone Receptor Beta

“…There is an urgent need for a better understanding of the important role of regulating protein folding in the plasticity of hormonal signals. Here, Hsp90 plays a prominent role in the complete activation of TRb by T3. , Hsp90 was identified as a biomarker for cell stress and protein maturation and is important for differentiation and development. Our data indicate that the breakdown of the Hsp90-TRb complex elicits the T3 response perhaps in two ways, arresting Hsp90 in the ATP-bound form and releasing TRb, and consequently, the folding machinery is stopped (Scheme ).…”

Personalized Proteomics for Precision Diagnostics in Hearing Loss: Disease-Specific Analysis of Human Perilymph by Mass Spectrometry

“…For biomarker identification, the definition of a biomarker needs careful consideration. 39 A biological marker can be objectively measured and evaluated as an indicator of physiological or pathological processes. 40 Generally, proteomic analysis based on MS can analyze every single protein in a system and determine causal biological relationships.…”

“…From other proteomic studies on bodily fluids, lists of up to hundreds of differentially expressed proteins are available. For biomarker identification, the definition of a biomarker needs careful consideration . A biological marker can be objectively measured and evaluated as an indicator of physiological or pathological processes .…”

Exosomes as drug delivery vehicles and biomarkers for neurological and auditory systems

“…The number of exosomes was decreased when the pathology was resolved. There have been several studies that have suggested that fluctuating levels of exosomes could be used as biomarkers in certain inner ear pathologies, including SNHL secondary to ototoxic medications and otitis media (Breglio et al, 2020;Gomaa et al, 2021;Pei et al, 2021;Val et al, 2017;Wong et al, 2018).…”

“…Many drugs for AD and PD have not been approved in clinical trials due to poor drug absorption and distribution across the BBB (Stimu & lus package, 2018). However, it has been observed that exosomes have a unique ability to cross the BBB even in a bidirectional manner (Alvarez et al, 2012;Gomez-Molina et al, 2019;Luo et al, 2020;Saint-Pol et al, 2020).…”