Nuclear factor erythroid 2-related factor 2 (Nrf2), tumor necrosis factor alpha protein (TNF-α), heme oxygenase-1 (HO-1) gene expressions during cardiopulmonary bypass

Objective: During extracorporeal circulation, blood is in contact with nonendothelial surfaces. The increase in the amount of blood touching the non-endothelial surface increases the damage to the blood elements. This initiates and increases oxidative stress. Increased oxidative stress leads to the activation of antioxidant systems. These two systems work gradually in the process of Cardiopulmonary Bypass. This study aims to investigate the changes of TNF-alpha, Nrf2 and HO-1 gene expression in extracorporeal circulation. Materials and Methods: Fifteen patients who underwent open heart surgery were included in the study. Blood samples were taken preoperatively, during cardiopulmonary bypass (CPB) and 24 hours postoperatively. TNF-alpha, Nrf2 and HO-1 gene expressions in plasma samples were studied by using appropriate kits. Changes in gene expressions were compared. Results: TNF-alpha gene expression increased during CPB compared to preoperative levels (p <0.05). Similarly, Nrf-2 gene expression increased significantly during CPB (p <0.001) and decreased postoperatively (p <0.001). There was a significant increase in HO-1 gene expression during CPB (p <0.01). Postoperatively, this increase was found to decrease similar to Nrf2 (p <0.05). Conclusions: According to the results, TNF-alpha, Nrf2, HO-1 gene expressions increase during CPB and these values decrease after the operation. This shows that oxidative stress and inflammatory processes start with CPB and antioxidant processes start similarly. With the termination of CPB, both processes are terminated. This has been demonstrated by gene expressions. Future studies will make it easier to understand these processes.

Automated summary

During cardiopulmonary bypass, TNF-alpha, Nrf2, and HO-1 gene expressions increase, and these values decrease postoperatively. This indicates that oxidative stress and inflammatory processes start with cardiopulmonary bypass, and antioxidant processes start similarly.