CD59 prevents human complement-mediated injuries in isolated guinea pig hearts

Area of Science:

• Cardiovascular Research
• Immunology
• Complement System Biology

Background:

• The complement system, a crucial part of innate immunity, can paradoxically mediate tissue damage.
• Complement-mediated injury is implicated in various cardiovascular pathologies.
• Understanding the direct effects of complement activation on the heart is essential for developing targeted therapies.

Purpose of the Study:

• To investigate complement-mediated myocardial injury in an isolated guinea pig working heart model.
• To evaluate the cardioprotective efficacy of CD59 against complement-induced cardiac damage.

Main Methods:

• Isolated guinea pig working hearts were perfused with plasma and zymosan to induce complement activation.
• Experimental groups included inactivated plasma (control), normal plasma, and normal plasma with CD59.
• Cardiac function (e.g., cardiac output, developed pressure) and electrocardiograms were monitored.
• Immunohistochemistry was used to detect complement components (C3a, C5b-9) in myocardial tissue.

Main Results:

• Perfusion with normal plasma and zymosan induced significant cardiac dysfunction, including decreased cardiac output and developed pressure, and ECG abnormalities.
• Immunohistochemistry confirmed the deposition of C3a and C5b-9 in the myocardium of hearts exposed to normal plasma.
• Hearts treated with CD59 exhibited preserved cardiac function and minimal complement deposition, similar to controls.

Conclusions:

• Human complement activation directly injures isolated guinea pig working hearts.
• CD59 effectively inhibits complement-mediated myocardial damage, demonstrating significant cardioprotective effects.
• These findings support the potential of CD59 as a therapeutic agent to mitigate complement-induced cardiac injury.