TRPM8, ASIC1, and ASIC3 localization and expression in the human oropharynx

Area of Science:

• Neuroscience
• Gastroenterology
• Pharmacology

Background:

• Oropharyngeal dysphagia (OD) is a common condition in older adults with limited treatment options.
• Polymodal sensory receptors, including TRP and ASIC families, are potential therapeutic targets for OD.
• Current understanding of TRPM8, ASIC1, and ASIC3 expression in the human oropharynx is limited.

Purpose of the Study:

• To investigate the expression and localization of TRPM8, ASIC1, and ASIC3 in human oropharyngeal tissue.
• To establish a foundation for developing novel pharmacological treatments for OD.

Main Methods:

• Human oropharyngeal samples from 20 patients (mRNA analysis) and 12 patients (immunohistochemistry) were analyzed.
• RT-qPCR and fluorescent immunohistochemistry were employed to study receptor expression and localization.
• Samples were obtained from regions innervated by cranial nerves V, IX, and X.

Main Results:

• ASIC3 and TRPM8 were expressed on sensory fibers in the oropharyngeal mucosa, below the basal lamina.
• ASIC1 was detected in nerves innervating tongue muscles.
• ASIC3 showed consistent expression across the three studied regions.

Conclusions:

• TRPM8 and ASIC3 are present on submucosal sensory nerves in the human oropharynx.
• These receptors represent promising therapeutic targets for OD.
• The findings support the development of new pharmacological interventions for OD patients.