title: Up-regulation of Fas ligand (FasL) mRNA expression in peripheral blood mononuclear cells (PBMC) after major surgery.
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.
authors.affiliation: Intensive Care Unit, Osaka University Hospital, Suita, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sugimoto
authors.forename: M
authors.initials: M
authors.lastname: Shimaoka
authors.forename: K
authors.initials: K
authors.lastname: Hosotsubo
authors.forename: H
authors.initials: H
authors.lastname: Tanigami
authors.forename: N
authors.initials: N
authors.lastname: Taenaka
authors.forename: H
authors.initials: H
authors.lastname: Kiyono
authors.forename: I
authors.initials: I
authors.lastname: Yoshiya
mesh_terms: D000368:Aged; D053222:Fas Ligand Protein; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008875:Middle Aged; D011183:Postoperative Complications / Q000276:immunology*; D012333:RNA, Messenger / Q000096:biosynthesis; D015854:Up-Regulation
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D012333:RNA, Messenger