Particulate Matter Elevates Ocular Inflammation and Endoplasmic Reticulum Stress in Human Retinal Pigmented...

Area of Science:

• Ophthalmology
• Cell Biology
• Environmental Health

Background:

• Eye exposure to air pollutants like particulate matter (PM) can lead to severe ocular pathologies.
• Prolonged ocular PM exposure is linked to increased retinal inflammation and endoplasmic reticulum (ER) stress.

Purpose of the Study:

• To investigate if PM exposure induces ocular inflammation and ER stress-related cellular responses in human retinal cells (ARPE-19).
• To elucidate the molecular mechanisms by which PM promotes ocular inflammation and ER stress.

Main Methods:

• ARPE-19 cells were exposed to varying doses of PM.
• Activation of the mitogen-activated protein kinase (MAPK)/nuclear factor kappa beta (NFκB) axis and inflammatory mRNA expression were monitored.
• Upregulation of ER-related unfolded protein response (UPR) pathways and intracellular calcium ([Ca2+]i) levels were measured as indicators of ER stress.

Main Results:

• PM exposure dose-dependently elevated cytokine mRNA expression and increased NFκB-MAPK axis phosphorylation.
• PM exposure significantly increased intracellular calcium levels and the expression of UPR-related proteins.
• These findings indicate ER stress induction, potentially due to cell hypoxia and subsequent activation of adaptive mechanisms.

Conclusions:

• Ocular PM exposure triggers inflammation in ARPE-19 cells by activating the MAPK/NFκB pathway and cytokine expression.
• PM exposure induces ER stress and adaptive stress responses in retinal cells.
• These results offer insights into the role of PM in ocular pathophysiology and its molecular mechanisms.