Granulocytes cell apoptosis

Kelly ML, Tang Y, Rosensweig N, Clejan S, Beckman BS (1998) Granulocyte-macrophage colony-stimulating factor rescues TF-1 leukemia cells from ionizing radiation-induced apoptosis through a pathway mediated by protein kinase Ca. Blood 92 416-424... 

In contrast to catechol and hydroquinone, phenol was a weak inducer of apoptosis in HL60 human promyelocytic leukaemia cells, and had an apoptotic effect only at the highest concentration tested (0.75 mmol/L) (Moran et al., 1996). Phenol (< 10 mmol/L) had no effect on the colony formation of granulocytes/macrophages induced by a recombinant granulocyte/macrophage colony-stimulating factor of murine bone-marrow cells (Irons et al., 1992). 

Takemura et al. [155] described TUNEL positivity, and Hayakawa et al. [152] described caspase-3 positivity in infiltrated and proliferated interstitial cells in an experimental model of MI, suggesting that apoptosis might play an important role in the disappearance of these cells after MI. Consistent with these studies, we found positive reaction for cleaved caspase-3 in neutrophil granulocytes in the interstitium in acute MI in humans (Fig. 4B). 

Preparations from the gum resin of Boswellia serrata have been used as traditional remedies in Ayurvedic medicine in India for inflammatory diseases (1). The gum contains substances that have anti-inflammatory properties they are pentacyclic triterpenes related to boswellic acid, which inhibit leukotriene biosjmthesis in neutrophilic granulocytes by inhibiting 5-lipoxygenase. Certain boswellic acids also inhibit elastase in leukocytes, inhibit proliferation, induce apoptosis, and inhibit topoisome-rases in cancer cell lines. 

Intracellular mechanisms governing apoptosis are as yet poorly understood. However, there are indications that internal controls in granulocytes may differ from lymphoid cells. In thymocytes, elevation of intracellular calcium concentration ([Ca " ] ) by calcium ionophores induces apoptosis, and apoptosis induced by other stimuli, such as glucocorticoids, is associated with rises in [Ca " ] (McConkey et al., 1989). However, in neutrophils spontaneously undergoing apoptosis, there were no such rises in [Ca " ] , and agents increasing [Ca " ] caused dramatic slowing of neutrophil apoptosis without... 

The arachidonate cascade includes the COX pathway to form prostanoids and the lipoxygenase (LOX) pathway to generate several oxygenated fatty acids, collectively called eicosanoids. While the exact mechanism remains unknown, it has been shown that eicosanoids play a dual role in regulating both cell survival and apoptosis in various types of cells [81]. One recent study, for example, demonstrated that arachidonic acid metabolites are involved in the regulation of apoptosis in human polymorphonuclear neutrophil granulocytes [82],... 

---