Analysis of self-renewing and differentiation-related microRNAs and transcription factors in multilineage mouse hematopoietic stem/progenitor cells induced by 1,4-benzoquinone

Background. HSPCs are targets for benzene-induced hematotoxicity and leukemogenesis. However, benzene toxicity targeting microRNAs (miRNAs) and transcription factors (TF) that are involve in regulating self-renewing and differentiation of HSPCs comprising of different hematopoietic lineages remains poorly understood. In this study, the effect of a benzene metabolite, 1,4-benzoquinone (1,4-BQ) exposure, in HSPCs focusing on the self-renewing (miRNAs: miR-196b and miR-29a; TF: HoxB4, Bmi-1) and differentiation (miRNAs: miR-181a, TF: GATA3) pathways were investigated. Methods. Freshly isolated mouse BM cells were initially exposed to 1,4-BQ at 1.25 to 5 mu M for 24 h, followed by miRNAs and TF studies in BM cells. Then, the miRNAs expression was further evaluated in HSPCs of different lineages comprised of myeloid, erythroid and pre-B lymphoid progenitors following 7-14 days of colony forming unit (CFU) assay. Results. Exposure to 1,4-BQ in BM cells significantly (p < 0:05) reduced the miR196b (2.5 and 5 mu M), miR-181a (1.25, 2.5 and 5 mu M) and miR-29a (1.25 mu M) along with upregulation of miR-29a at 2.5 mu M. Meanwhile, 1,4-BQ exposure in HSPCs significantly increased the miR-196b expression level (p<0:05) only in myeloid and pre-B lymphoid progenitors at 2.5 and 5 mu M. Significant (p < 0:05) reduction in expression of miR-181a in myeloid (1.25 mu M), erythroid (5 mu M) progenitors along with miR-29a in myeloid (1.25 mu M) and pre-B lymphoid (5 mu M) progenitors were noted following exposure to 1,4-BQ. Meanwhile, increased expression of miR-181a was observed in pre-B lymphoid progenitor upon exposure to 1,4-BQ, but only at 5 mu M. As for TF studies, expression of HoxB4 protein was significantly increased (p<0.05) at all 1,4-BQ concentrations as compared to Bmi-1 and GATA3, which were significantly (p<0.05) elevated starting at 2.5 mu M of 1,4-BQ. Conclusion. 1,4-BQ induces aberration of miRNAs and transcription factors protein expression that are involved in regulating self-renewing and differentiation pathways of HSPCs. Moreover, epigenetic toxicity as evidenced from the miRNAs expression found to be mediated by a lineage-driven mechanism. The role of cell lineage in governing the toxicity of 1,4-BQ in HSPCs lineages deserves further investigation.