Static magnetic field selects undifferentiated myelomonocytes from low-glutamine concentration stimulated U937 cells

An increasing number of evidence indicates that static magnetic fields (SMF) are capable of altering apoptosis, mainly through modulation of Ca2+ influx. Here we present data that suggest apoptotic-related gene expression as an alternative pathway, through which exposure to 6 milliTesla (mT) SMF can interfere with apoptosis. Exposure to 6 mT SMF affects the apoptotic rate (spontaneous and drug-induced) and [Ca2+]i in isolated human lymphocytes; the aged cells are more susceptible to exposure than fresh ones. The exposure to 6 mT exerted a protective effect on chemical or physical-induced apoptosis, irrespective of the age of the cells. The investigation of the gene expression of bcl-2, bax, p53 and hsp70 in freshly isolated and in culture aged human lymphocytes indicates that these genes are modulated by SMF exposure in the experimental conditions used, in a gene-, age- and time- dependent manner. The exposure of isolated lymphocytes to SMF for up 24 h modulated increased bax and p53 and decreased hsp70, and bcl-2. The amount of increment and/or decrement of the proteins varied for each gene examined and was independent of the apoptotic inducers. Finally, the same stress applied to freshly isolated or aged lymphocytes resulted in different modulation of bcl-2, bax and hsp70.