Four different classes of inhibitors of receptor-mediated endocytosis decrease tumor necrosis factor-induced gene...

Area of Science:

• Cell Biology
• Immunology
• Molecular Biology

Background:

• Receptor-mediated endocytosis is a key cellular process.
• Tumor necrosis factor (TNF) plays a crucial role in inflammatory responses.
• Understanding the link between TNF endocytosis and gene expression is vital for therapeutic development.

Purpose of the Study:

• To investigate the relationship between receptor-mediated endocytosis of TNF and TNF-induced gene expression in human endothelial cells.
• To explore the potential of inhibiting endocytosis as an anti-inflammatory therapeutic strategy.

Main Methods:

• Utilized various treatments (hypertonicity, acidification, phenylarsine oxide, primary amines) to inhibit receptor-mediated endocytosis.
• Measured endocytosis via uptake of labeled low-density lipoprotein and 125I-TNF.
• Assessed TNF-induced gene expression (ELAM-1, ICAM-1, VCAM-1) and cytokine-mediated gene induction using techniques like [35S]methionine incorporation and mRNA analysis.

Main Results:

• Hypertonicity, acidification, phenylarsine oxide, and primary amines inhibited receptor-mediated endocytosis by 30-75%.
• These treatments also inhibited TNF-induced ELAM-1 expression by 50-100%.
• Primary amines selectively inhibited TNF-induced gene expression and reduced mRNA levels without affecting constitutive molecules like gp96.

Conclusions:

• Receptor-mediated endocytosis plays a significant role in TNF-mediated gene induction.
• Primary amines show promise as a targeted approach to inhibit inflammatory gene expression by interfering with endocytosis.
• Targeting receptor-mediated endocytosis presents a potential new avenue for anti-inflammatory therapies.