PCB-induced endothelial cell dysfunction: role of poly(ADP-ribose) polymerase

Area of Science:

• Environmental Health
• Cardiovascular Science
• Toxicology

Background:

• Polychlorinated biphenyls (PCBs) are persistent pollutants linked to inflammation and atherosclerosis.
• Endothelial cell dysfunction from PCBs involves oxidative stress, inflammation, and cell death.
• The role of PCBs in vascular relaxant responses and PARP activation was previously unexamined.

Purpose of the Study:

• To investigate if 2,2',4,6,6'-pentachlorobiphenyl (PCB 104) directly causes endothelial cell dysfunction.
• To determine if PCB 104-induced dysfunction involves oxidative stress and poly(ADP-ribose) polymerase (PARP) overactivation.
• To assess the impact of PCB 104 on vascular relaxant responses.

Main Methods:

• Ex vivo exposure of rat aortic rings to varying concentrations and durations of PCB 104.
• In vitro exposure of mouse endothelial cells to PCB 104.
• Measurement of cellular oxidative stress, PARP activation, and NADPH levels.
• Pharmacological inhibition of CYP1A1 and PARP to assess protective effects.

Main Results:

• PCB 104 exposure impaired acetylcholine-mediated relaxation in rat aortic rings in a dose- and time-dependent manner.
• In mouse endothelial cells, PCB 104 increased oxidative stress via CYP1A1 activation, leading to PARP overactivation and NADPH depletion.
• Inhibition of CYP1A1 or PARP prevented PCB 104-induced endothelial cell dysfunction.

Conclusions:

• PCBs, specifically PCB 104, directly impair endothelial cell function.
• Overactivation of PARP, triggered by PCB-induced oxidative stress, is a key mechanism in PCB-mediated endothelial dysfunction.
• These findings suggest PCBs contribute to hypertension and cardiovascular disease development by affecting vascular function.