Man-made mineral fibers induce apoptosis of human peripheral blood mononuclear cells similarly to chrysotile B

The aim of this study was to investigate whether man-made mineral fibers (M MMF) induce apoptosis of human peripheral blood mononuclear cells (PBMC), a s we recently demonstrated for chrysotile B. In vitro cultivation of PBMC w ith various MMMF as well as chrysotile B clearly produced apoptotic cells. The alteration of the expression for apoptosis related genes at the mRNA le vel during in vitro cultures of PBMC with various MMMF revealed upregulatio n of Flice and Apaf-1 genes and down regulation of TNF receptor 1 and Bid g enes. These results indicate that MMMF induce apoptosis of PBMC in a simila r manner to chrysotile B. However, the process may be mediated not only by the Fas-related apoptotic pathway but also a mitochondrial pathway. Thus, o ne should be aware that respiratory and immunological abnormalities may occ ur in workers who are exposed to MMMFs.