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Up-regulation of Fas ligand (FasL) mRNA expression in peripheral blood mononuclear cells (PBMC) after major surgery
M Sugimoto1, M Shimaoka, K Hosotsubo
1Intensive Care Unit, Osaka University Hospital, Suita, Japan.
Abstract:
FasL, which is expressed mainly on activated lymphocytes, can induce apoptosis (programmed cell death) of cells which express Fas. Fas/FasL interaction is primarily beneficial in maintaining immunological and physiological homeostasis by eliminating unnecessary cells. Dysregulation of the interaction, however, leads to tissue damage. We investigated how Fas/FasL levels changed after major surgery. The major aim of this study was to elucidate the involvement of the Fas/FasL system in postoperative inflammation. The investigation involved 10 patients admitted to the intensive care unit after surgery. Although the percentage of Fas+ cells and the amount of Fas expression tended to increase, there was no significant difference between pre- and post-operative samples. In contrast, the levels of FasL mRNA were dramatically up-regulated after operation. Post-operative C-reactive protein (CRP) levels increased and correlated well with FasL levels (r=0.91, P<0.01). Lymphocyte counts decreased after operation and were inversely proportional to FasL levels (r=0.58, P < 0.05). These results suggest that the enhanced FasL expression is likely to be related to systemic inflammatory responses induced during the perioperative period. FasL up-regulation may be involved in the aggravation of tissue damage, including lymphocytopenia, in the early post-operative period.
Insights
Major surgery significantly increases FasL mRNA levels, correlating with inflammation and decreased lymphocytes. This suggests the Fas/FasL system contributes to postoperative tissue damage and lymphocytopenia.
Area of Science:
- Immunology
- Surgical Pathology
- Cellular Biology
Background:
- The Fas/FasL system regulates apoptosis and immune homeostasis.
- Dysregulation of Fas/FasL interaction can cause tissue damage.
- Postoperative inflammation is a complex response following major surgery.
Purpose of the Study:
- To investigate changes in Fas/FasL system components after major surgery.
- To elucidate the role of the Fas/FasL system in postoperative inflammation.
- To explore the relationship between Fas/FasL levels and postoperative inflammatory markers.
Main Methods:
- Studied 10 intensive care unit patients post-major surgery.
- Measured Fas+ cell percentage and Fas expression pre- and post-operation.
- Quantified FasL mRNA levels and C-reactive protein (CRP) post-operation.
- Assessed lymphocyte counts and correlated them with FasL levels.
Main Results:
- FasL mRNA levels were significantly upregulated post-surgery.
- Postoperative CRP levels correlated positively with FasL levels (r=0.91, P<0.01).
- Lymphocyte counts decreased post-surgery, showing an inverse relationship with FasL levels (r=0.58, P<0.05).
- No significant changes were observed in Fas+ cell percentage or Fas expression.
Conclusions:
- Enhanced FasL expression post-surgery is linked to systemic inflammatory responses.
- FasL upregulation may exacerbate postoperative tissue damage, including lymphocytopenia.
- The Fas/FasL system plays a role in the early inflammatory phase after major surgery.