# Low expression of TGF‐β2 and matrilin2 in human aqueous humour with acute primary angle closure

## TL;DR

This study identifies TGF-β2 and matrilin2 as proteins with lower expression in the eye fluid of patients with acute primary angle closure, potentially offering new biomarkers for diagnosing this form of glaucoma.

## Contribution

The study discovers novel downregulated proteins in acute primary angle closure eye fluid, suggesting their role in disease mechanisms.

## Key findings

- Transforming growth factor-β2 and matrilin2 are downregulated in acute primary angle closure aqueous humour.
- Differentially expressed proteins are linked to inflammation, fibrosis, and extracellular matrix formation.
- Over 400 proteins were identified, with 91 showing significant differences between the groups.

## Abstract

Primary angle‐closure glaucoma (PACG) is the leading cause of irreversible blindness in the world. Angle closure induced by pupil block and secondary iris synechia is the fundamental pathology of the PACG. The molecular mechanisms of angle closure have not yet been clearly illustrated. This study was designed to investigate the protein difference in the aqueous humour and explore new biomarker of the PACG. Aqueous humour (AH) was collected from patients with acute primary angle closure (APAC) and cataract (n = 10 in APAC group) and patients with cataract only (n = 10 in control group). Samples were pooled and measured using label‐free proteome technology. Then, the differentially expressed proteins (DEPs) were verified by ELISA using independent AH samples (n = 20 each group). More than 400 proteins were revealed in both groups through proteomics. Comparing the two groups, there were 91DEPs. These proteins participate in biological activities such as inflammation, fibrosis, nerve growth and degeneration and metabolism. We found that the expression of transforming growth factor‐β2 and matrilin2 was downregulated in the APAC group. The two proteins are related to inflammation and extracellular matrix formation, which might be involved in angle closure. This study characterized DEPs in AH of the APAC and found a downregulated protein matrilin2.