The IRE1α Pathway Links Endoplasmic Reticulum Stress to Atherosclerosis-Related Inflammation and Lipid Accumulation

Area of Science:

• Cellular biology
• Immunology
• Molecular medicine

Background:

• Endoplasmic reticulum stress (ER stress) is implicated in atherosclerosis pathogenesis via inflammation and foam cell formation.
• The precise mechanisms linking ER stress to atherosclerosis require further investigation.
• The inositol-requiring enzyme 1 alpha (IRE1α) pathway is a key component of the unfolded protein response (UPR).

Purpose of the Study:

• To investigate the role of the IRE1α arm of the UPR in regulating inflammatory cytokine expression in monocytes.
• To examine the impact of IRE1α on intracellular lipid accumulation in macrophages.
• To elucidate the mechanisms by which ER stress contributes to atherosclerosis.

Main Methods:

• CRISPR/Cas9 gene editing was used to create an IRE1α knockout (KO) THP-1 monocytic cell line.
• THP-1 cells were differentiated into macrophages for further analysis.
• Quantitative real-time PCR (qPCR) and ELISA were employed to measure cytokine expression (IL-1β, IL-6, TNFα).
• Intracellular cholesterol accumulation and gene expression (CD36, ABCA1) were assessed after LDL exposure.

Main Results:

• IRE1α knockout significantly reduced TNFα, IL-1β, and IL-6 expression following lipopolysaccharide (LPS) stimulation.
• ELISA confirmed substantially lower cytokine secretion in IRE1α KO monocytes.
• IRE1α deficiency impaired the cellular response to atherogenic LDL, inhibiting lipid-induced CD36 and ABCA1 upregulation.

Conclusions:

• IRE1α is a critical regulator of inflammatory cytokine expression and lipid metabolism in THP-1 cells.
• Targeting IRE1α presents a potential therapeutic strategy for inflammatory diseases and atherosclerosis.
• Modulating IRE1α may offer novel approaches to manage inflammation and lipid dysregulation in cardiovascular diseases.