Nontoxic proteasome inhibition activates a protective antioxidant defense response in endothelial cells

Area of Science:

• Molecular Biology
• Cell Biology
• Cardiovascular Research

Background:

• The ubiquitin-proteasome system is a therapeutic target for proliferative and inflammatory diseases.
• Understanding dose-dependent cellular effects of proteasome inhibitors is crucial for therapeutic applications.

Purpose of the Study:

• To elucidate complex cellular effects of toxic versus nontoxic proteasome inhibition in human endothelial cells.
• To compare expressional profiling between toxic and nontoxic proteasome inhibition doses.
• To investigate the therapeutic potential of nontoxic proteasome inhibition in endothelial dysfunction.

Main Methods:

• Expressional profiling of human endothelial cells treated with proteasome inhibitors.
• Dose-response analysis of proteasome inhibitor effects.
• Assessment of endothelial cell protection against oxidative stress (H2O2).
• Functional analysis using rat aortic rings.

Main Results:

• Nontoxic proteasome inhibitor doses induced a defined, dose-dependent transcriptional response.
• Toxic doses showed a significantly greater number of regulated genes and amplitude compared to nontoxic doses.
• Upregulation of antioxidative enzymes and differential regulation of endothelial function genes were observed with nontoxic doses.
• Nontoxic proteasome inhibition protected endothelial cells from oxidative stress and improved endothelial function in rat aortic rings.

Conclusions:

• Nontoxic proteasome inhibition elicits a distinct adaptive transcriptional response in endothelial cells.
• This response confers protection against oxidative stress and improves endothelial function.
• Nontoxic proteasome inhibition represents a promising therapeutic strategy for endothelial dysfunction in cardiovascular disorders.