Expressions of isopeptide bonds and corneodesmosin in middle ear cholesteatoma

Biomarkers in Otorhinolaryngology

Biomarkers of otorhinolaryngologic diseases with higher insult over a person’s him/herself and overall health services are summarized in brief. In order to define, diagnose, treat and monitor any disease markers are needed. Otorhinolaryngology (ORL) is interested in special disease entities of the region besides otorhinolaryngologic involvements of the systemic diseases and unique forms of pathologies such as cholesteatoma, Meniere’s disease and otosclerosis. Neoplasia is another heading to deal with. In the following chapter, one will find an overview of molecules that have been used as a biomarker as well as the end points of the present research on the issue relevant with ORL. Day by day, new molecules are being named however, the pathways of action are rather the same. Readers will find the headings related to the most common diseases of the field, informing them about where to look for defining new strategies of understanding of each disease.

Extensive qPCR analysis reveals altered gene expression in middle ear mucosa from cholesteatoma patients

The middle ear is a small and hard to reach compartment, limiting the amount of tissue that can be extracted and the possibilities for studying the molecular mechanisms behind diseases like cholesteatoma. In this paper 14 reference gene candidates were evaluated in the middle ear mucosa of cholesteatoma patients and two different control tissues. ACTB and GAPDH were shown to be the optimal genes for the normalisation of target gene expression when investigating middle ear mucosa in multiplex qPCR analysis. Validation of reference genes using c-MYC expression confirmed the suitability of ACTB and GAPDH as reference genes and showed an upregulation of c-MYC in middle ear mucosa during cholesteatoma. The occurrence of participants of the innate immunity, TLR2 and TLR4, were analysed in order to compare healthy middle ear mucosa to cholesteatoma. Analysis of TLR2 and TLR4 showed variable results depending on control tissue used, highlighting the importance of selecting relevant control tissue when investigating causes for disease. It is our belief that a consensus regarding reference genes and control tissue will contribute to the comparability and reproducibility of studies within the field.

Expressions of TRPVs in the cholesteatoma epithelium

OBJECTIVE

We have recently proposed a hypothesis that acid leakage through the cholesteatoma epithelium mediates bone resorption in middle ear cholesteatoma. In the present study, we investigated the expressions of transient receptor potential vanilloid (TRPV) channels, which have been shown to play roles in the regulation of epidermal barrier function, in the cholesteatoma epithelium in comparison with the normal skin.

METHODS

Cholesteatoma epithelium and postauricular skin were collected from 17 patients with primary acquired middle ear cholesteatoma who underwent tympanomastoidectomy. Expressions of TRPV1, TRPV3, TRPV4, and TRPV6 were explored by fluorescence immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR).

RESULTS

TRPV1, TRPV3, TRPV4, and TRPV6 mRNAs were all detected by qRT-PCR both in the skin and cholesteatoma tissue. Immunohistochemical staining showed that TRPV1 and TRPV3 were positive in the viable cell layers of the epidermis of the skin, and only TRPV3 was positive in those of the cholesteatoma epithelium. The immunoreactivity for TRPV3 was significantly weaker in cholesteatoma than in the skin.

CONCLUSIONS

The lower expression of TRPV3 in cholesteatoma may be one of the mechanisms underlying the increased permeability of this tissue. On the other hand, TRPV1, TRPV4, and TRPV6 are unlikely to be involved in the regulation of epithelial permeability in cholesteatoma.