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Circulating neutrophils exhibit enhanced apoptosis associated with mitochondrial dysfunctions after surgery under
G Delogu1, S Moretti, G Famularo
1Institute of Anaesthesia & Intensive Care, La Sapienza University, Rome, Italy. giovanna.delogu@uniroma1.it
Background:
Evidence suggests that apoptosis plays a main role in the postoperative changes detected in the polymorphonuclear neutrophil (PMN) population. Furthermore, recent studies have demonstrated that mitochondrial alterations constitute critical events of the apoptotic cascade. In this study we investigated whether apoptosis among neutrophils taken from patients undergoing surgical trauma could be associated with perturbation of mitochondrial transmembrane potential (deltapsim) and/or exaggerated production of mitochondrial reactive oxygen species (ROS).
Methods:
Twenty-seven patients undergoing elective surgery under general anaesthesia were enrolled in the study. Peripheral blood samples were drawn one day before the operation and at 12 and 24 h after surgery. Apoptosis rate was assessed by staining neutrophils with 7-amino-actinomycin D (7-AAD) and by analysis by a FACScan flow cytometer. In order to evaluate deltapsim, cells were exposed to 3,3-dihexyloxacarbocyanine iodide [DiOC6(3)]; intracellular ROS was measured by means of hydroethidine (HE) and 2,7-diclorofluorescein diacetate (DCFH-DA), followed by analysis on a cytofluorometer.
Results:
At 12 h following surgery we observed a significantly (P<0.05) increased frequency of apoptotic PMNs compared to that preoperatively (30.79+/-3.68% vs 7.40+/-0.69%). At this same time-point, the rate of neutrophils stained with HE, DCFH-DA and [DiOC6(3)] were significantly (P<0.05) higher compared to baseline (51.05+/-5.44%, 50.58+/-5.84% and 55.31+/-4.33% vs 20.17+/-2.38%, 19.59+/-2.03 and 25.43+/-2.71% respectively). Overall measurements returned to the preoperative values 24 h after surgery.
Conclusion:
These data suggest that surgery under general anaesthesia triggers in the immediate postoperative period pathways of PMN accelerated apoptosis associated with significant alterations in mitochondrial function.
Insights
Surgery under general anesthesia accelerates polymorphonuclear neutrophil (PMN) apoptosis postoperatively. This process is linked to mitochondrial dysfunction, including altered transmembrane potential and increased reactive oxygen species (ROS) production.
Area of Science:
- Immunology
- Cell Biology
- Surgical Science
Background:
- Apoptosis significantly impacts polymorphonuclear neutrophil (PMN) populations after surgery.
- Mitochondrial alterations are key events in the apoptotic cascade.
Purpose of the Study:
- To investigate if apoptosis in neutrophils from surgical trauma patients is associated with mitochondrial transmembrane potential (deltapsim) perturbation and/or increased mitochondrial reactive oxygen species (ROS) production.
Main Methods:
- Blood samples from 27 patients undergoing elective surgery were analyzed preoperatively and at 12 and 24 hours post-surgery.
- Apoptosis rate was assessed using 7-amino-actinomycin D (7-AAD) and flow cytometry.
- Mitochondrial function was evaluated by measuring deltapsim with [DiOC6(3)] and ROS production with hydroethidine (HE) and DCFH-DA.
Main Results:
- A significant increase in apoptotic PMNs was observed 12 hours post-surgery (30.79% vs 7.40% preoperatively).
- At 12 hours, neutrophils showed significantly higher rates of HE, DCFH-DA, and [DiOC6(3)] staining, indicating increased ROS and altered deltapsim.
- These parameters returned to baseline levels 24 hours after surgery.
Conclusions:
- General anesthesia and surgical trauma induce accelerated PMN apoptosis in the early postoperative period.
- This accelerated apoptosis is associated with significant mitochondrial dysfunction, including changes in deltapsim and ROS production.