PAHs Target Hematopoietic Linages in Bone Marrow through Cyp1b1 Primarily in Mesenchymal Stromal Cells but Not AhR: A Reconstituted In Vitro Model

Figure 3

Effect of PAH treatment on WT progenitor activity in OP9 coculture from the fresh BMC preparation without in vitro culture. (a) Experimental design for assessing effects of PAHs on progenitor proliferation (PreB CFU activity) of cultured BMC. Cells isolated from the BM of mice of different genotypes are cocultured with serum media for 24 hours alone, on a monolayer stromal support (OP9 or BMS2 cells) or media enriched by 24-hour culture with OP9 cells (OP9-EM). PAH (1 M), TCDD (0.01 M), or an equivalent volume of DMSO solvent is added at the beginning of the 24-hour period. BMC (5 × 10⁵ cells) are added to the CFU methyl cellulose suspension assay at the end of 24 hours. Direct addition of BMC to the CFU assay provides a 100 percent reference activity. (b) Effect of DMBA (1 M) in OP9 coculture compared with effect in enriched medium (OP9-EM). Statistical significance; value < 0.05. (c) OP9 coculture experiments with DMBA (1 M), BP (1 M), and TCDD (0.01 M) treatments showed significant () loss of activity after 24-hour treatment, as compared with the DMSO solvent control.

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