Expression of c-jun/c-fos mRNA Indicates Persistent Myocardial Stretch During Asphyxia-Induced Cardiac Arrest

Area of Science:

• Cardiology
• Translational Medicine
• Molecular Biology

Background:

• Right ventricular dysfunction is a critical factor affecting the success of donation-after-circulatory-death (DCD) heart transplantation.
• DCD hearts experiencing volume overload are particularly susceptible to exacerbated right ventricular dysfunction post-transplant.
• Myocardial cell stretch, a response to mechanical stress, is implicated in cardiac dysfunction.

Purpose of the Study:

• To investigate the temporal dynamics of myocardial cell stretch in the right ventricle during asphyxia-induced cardiac arrest.
• To compare right ventricular and left ventricular responses to cardiac arrest at the molecular level.
• To elucidate the potential mechanisms underlying right ventricular dysfunction in the context of DCD heart transplantation.

Main Methods:

• Utilized a rat model of asphyxia-induced cardiac arrest.
• Measured c-jun/c-fos mRNA expression, a marker of immediate early gene response to cell stretch, in ventricular tissues at 0, 15, 30, and 45 minutes post-arrest.
• Employed droplet digital polymerase chain reaction (ddPCR) for precise quantification of mRNA levels.

Main Results:

• Left ventricle c-jun/c-fos mRNA levels showed a rapid increase at 15 minutes, returning to baseline by 30 minutes.
• Right ventricle c-jun/c-fos mRNA levels exhibited a gradual increase, peaking at 30 minutes post-arrest.
• These findings indicate a more prolonged period of myocardial cell stretching in the right ventricle compared to the left ventricle.

Conclusions:

• Prolonged myocardial cell stretching in the right ventricle following asphyxia-induced cardiac arrest may contribute to post-transplant right ventricular dysfunction.
• Understanding these molecular responses is crucial for improving outcomes in DCD heart transplantation.
• Further research into mitigating right ventricular stretch could enhance DCD heart graft viability.