Neutrophil Apoptosis by Fas/FasL: Harmful or Advantageous in Cardiac Surgery?

Abstract

Polymorphonuclear leukocytes or neutrophils are the main executors of cellular death, both in septic inflammation during bacterial infection and in sterile inflammation during trauma or surgery. Whereas in septic inflammation neutrophils perform a useful function to fortify the host's defense against infection, in sterile inflammation, by contrast, they contribute to unwelcome tissue damage. Regardless of the situation, activated neutrophils exhibit a prolonged lifespan and delayed apoptotic death which, under normal conditions, is a prerequisite for their natural renewal. Traditionally, delayed neutrophil apoptosis was considered to promote trauma or surgical injury. According to the results of recent studies, however surprising they may appear, the reverse might be in keeping with what happens IN VIVO. Apoptotic signaling in neutrophils could, by contrast, contribute to intrinsic protection of the host's tissues. This review article, aimed preferentially but not exclusively at the cardiac surgeon, presents some new information in support of this viewpoint, which fits in with our own observations.

Expression of CD200/CD200R regulatory molecules on granulocytes and monocytes is modulated by cardiac surgical operation

“…Conversely, augmentation of neutrophil apoptosis accelerates resolution of inflammation. We found that the expression of the pro-apoptotic membrane molecule Apo/Fas (CD95) on granulocytes was significantly increased late in the postoperative period on the 3 rd and 7 th postoperative days in patients with standard cardiopulmonary bypass 21 . In this regard, the significantly increased expression of CD200R on granulocytes, which was found immediately after surgery in the OP group, seems to be a very early endogenous protective mechanism that may intervene in order to dampen the exaggerated inflammatory response due to cardiac surgery.…”

Brucella abortus Invasion of Osteoblasts Inhibits Bone Formation

“…In line with the first proposed mechanism, we showed that B. abortus infection can induce apoptosis of primary mouse osteoblasts. Whether pathogen-induced apoptosis is harmful or beneficial to the host has been a considerable source of debate (26,56). Osteoblast apoptosis may be responsible, at least in part, for the damage produced by Brucella infection to bone since apoptosis would reduce the number of osteoblasts in bone.…”

Genetic polymorphisms of TP53 and FAS promoter modulate the progression of coronary artery disease after coronary artery bypass grafting: a gender-specific view

“…Cardiosurgical procedures are inseparately associated with systemic inflammatory response, predominantly when patients have undergone surgery under extracorporeal circulation. That may lead to postoperative complications such as acute lung injury, cardiac low output syndrome, and in extreme cases to multi-organ failure [7,8] Here, TLR receptors play a major role. It has previously been shown that a close link exists between inflammation and apoptosis in atherosclerotic plaques, and our data support these findings.…”

“…TLRs are highly conserved genes which mediate the production of cytokines necessary for the development of effective immunity. This gene is expressed most abundantly in peripheral blood leukocytes, and mediates host response to Gram-positive bacteria and yeast via stimulation of NF-jB [7,8].…”