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. 2011 Jul 25;108(33):13618–13623. doi: 10.1073/pnas.1105887108

Fig. 3.

Fig. 3.

Similar biological activity of erionite from North Dakota and Cappadocia, Turkey. (A) HM cells were cocultured with macrophages and exposed to either erionite or glass beads (control). After 6–8 wk of culture, foci were observed in erionite-exposed cells but not in glass beads-treated cells. (i) HM; (ii) HM cocultured with macrophages; (iii–vi) HM cocultured with macrophages and exposed to (iii) glass beads, (iv) US erionite from ND, (v) US erionite from Oregon, and (vi) Turkey erionite. (B) After 2 mo in culture, the numbers of tridimensional foci formed in HM cells under different treatment conditions were counted. Treatments were done in triplicates. OR, Oregon; TUR, Turkey. *P < 0.05 and ***P < 0.0001 compared with glass beads using unpaired t test. (C) Western blot analyses show that exposure to erionite fibers induced the release of HMGB1 by HM and TNF-α by macrophages. In the untreated negative control (lane 1) or cells treated with glass beads (lane 2), HMGB1 is mostly retained intracellularly (IC). HMGB1 was released from the HM cells into the conditioned medium (CM) as the cells underwent programmed necrosis, which is induced by exposure to US erionite from ND (lane 3), US erionite from Oregon (lane 4), or Turkey erionite (lane 5). Crocidolite asbestos (lane 6) was used as a positive control. Macrophages produced and secreted TNF-α into the conditioned medium 48 h after being exposed to the erionite fibers. (D) Immunohistochemical analyses show HMGB1 staining around areas of inflammation caused by crocidolite and erionite deposits. At low magnification (100×) H&E staining shows areas of the greater omentum from the peritoneum of mice injected with ASB or ND erionite or TUR erionite. Analysis at higher magnification (400×) shows adipose tissues with asbestos and erionite fibers surrounded by inflammatory cells, macrophages, giant cells, and lymphocytes. On the same samples, HMGB1 is detected in both cytoplasm and extracellular space where F4/80 and wide spectrum cytokeratin antibodies identify macrophages and mesothelial cells, respectively.