# Proteomics and Bioinformatics Profiles of Human Mesothelial Cell Line MeT-5A

## TL;DR

This study provides the first detailed proteome of mesothelial cells and their secreted proteins, offering insights into their biological functions.

## Contribution

The study presents the first comprehensive baseline proteome of mesothelial cells and their secreted medium.

## Key findings

- The study identified 5087 protein groups in mesothelial cells, with distinct functional profiles between intracellular and secreted proteins.
- Shared and compartment-specific proteins revealed insights into cellular and extracellular coordination in mesothelial cells.

## Abstract

Background: Despite existing proteomics studies of other cell types, a comprehensive proteome of mesothelial cells has not been characterized. This study establishes a crucial baseline proteome for mesothelial cells to better understand their fundamental bioprocesses in healthy and injured states. Methods: Using mass spectrometry-based shotgun proteomics, we characterized the cellular fraction (CF) and conditioned medium (CM) proteomes of mesothelial cell line MeT-5A. The datasets were analyzed for Gene Ontology (GO) terms and canonical pathway enrichments to identify biological themes. Results: Our analysis identified 5087 protein groups, including 1532 shared proteins, 3122 unique to the CF and 433 exclusive to the CM. GO annotation revealed distinct functional enrichment profiles, reflecting the differing roles of intracellular and secreted proteins. While intracellular proteins were linked to core cellular functions, the extracellular proteome was enriched for signaling and cell-to-cell interaction pathways. The proteins shared by both compartments provided an integrated view of the molecular coordination between the cellular and extracellular environments. Conclusions: This study provides the first comprehensive baseline proteome for mesothelial cells and their secreted medium, offering a vital resource for future investigations into the mesothelium, particularly in the context of disease or injury.