Distinct Functional Signatures of Human Olfactory and Respiratory Mucus Revealed by Proteomics Combined With Machine...

Area of Science:

• Biochemistry
• Proteomics
• Immunology

Background:

• The nasal cavity contains two distinct epithelial regions: olfactory and respiratory, each with different functions.
• The mucus composition of these regions is not well understood.

Purpose of the Study:

• To analyze and compare the mucosal secretomes of the human olfactory and respiratory regions.
• To identify distinct molecular signatures differentiating olfactory mucus (OM) and respiratory mucus (RM).

Main Methods:

• Collected human OM and RM samples from 25 normosmic individuals.
• Utilized label-free quantitative proteomics (LFQ) for protein analysis.
• Applied Partial Least Squares Discriminant Analysis (PLS-DA) for molecular signature discrimination, alongside Gene Ontology (GO) and Reactome pathway analyses.

Main Results:

• Quantified 1,780 high-confidence proteins across 50 samples.
• Achieved robust discrimination between OM and RM using PLS-DA (AUC = 0.93 ±0.04).
• Confirmed findings through cross-validation with GO, Reactome, and PLS-DA analyses, demonstrating biological coherence.

Conclusions:

• Defined two complementary nasal mucosal ecosystems: olfactory and respiratory.
• Olfactory mucus is optimized for mitochondrial activity, ciliary renewal, and autophagy.
• Respiratory mucus is specialized for immune defense and host protection.