Cytochrome P450 genes play central roles in transcriptional response by keratinocytes to a high-voltage alternating current electric field
Authors: Aoki, Masayo; Matsumoto, Noriko M.; Okubo, Yuri; Ogawa, Rei
The endogenous electric field (EF) of skin wounds plays an important role in the biological processes that underlie wound healing. Treatments that modulate wound-EFs promote healing. However, the mechanism(s) that underlie this effect remain unclear. Agilent-based microarrays were used to determine the transcriptomes of the keratinocyte line HaCaT, normal human dermal fibroblasts, and the human dermal endothelial cell line HMEC-1 before and after high-voltage alternating current (AC)-EF (14,000 V, 90 Hz) treatment. The keratinocytes had the most genes whose transcription was altered by EF. They included the cytochrome P450 (CYP) genes CYP1A1 and CYP1B1, HMOX1, EREG, DUSP5, and SLC7A1 1 (all upregulated), and DOCK8, ABCC6, and CYP26A1 (all downregulated). As shown by transcriptional-network analysis, all three CYP genes played central roles in the EF-induced changes in keratinocyte transcriptome. To the best of our knowledge, this is the first study that demonstrates that CYP genes play a key role in the transcriptional responses of human keratinocytes to EF treatment. Further investigations into the effects of EF on wound healing, aging, and regenerative medicine are likely to yield promising results. (C) 2018 Elsevier B.V. All rights reserved.
PML/RARa Interferes with NRF2 Transcriptional Activity Increasing the Sensitivity to Ascorbate of Acute Promyelocytic Leukemia Cells
Authors: Banella, Cristina; Catalano, Gianfranco; Travaglini, Serena; Divona, Mariadomenica; Masciarelli, Silvia; Guerrera, Gisella; Fazi, Francesco; Lo-Coco, Francesco; Voso, Maria Teresa; Noguera, Nelida Ines
NRF2 (NF-E2 p45-related factor 2) orchestrates cellular adaptive responses to stress. Its quantity and subcellular location is controlled through a complex network and its activity increases during redox perturbation, inflammation, growth factor stimulation, and energy fluxes. Even before all-trans retinoic acid (ATRA) treatment era it was a common experience that acute promyelocytic leukemia (APL) cells are highly sensitive to first line chemotherapy. Since we demonstrated how high doses of ascorbate (ASC) preferentially kill leukemic blast cells from APL patients, we aimed to define the underlying mechanism and found that promyelocytic leukemia/retinoic acid receptor alpha (PML/RARa) inhibits NRF2 function, impedes its transfer to the nucleus and enhances its degradation in the cytoplasm. Such loss of NRF2 function alters cell metabolism, demarcating APL tissue from both normal promyelocytes and other acute myeloide leukemia (AML) blast cells. Resistance to ATRA/arsenic trioxide (ATO) treatment is rare but grave and the metabolically-oriented treatment with high doses of ASC, which is highly effective on APL cells and harmless on normal hematopoietic stem cells (HSCs), could be of use in preventing clonal evolution and in rescuing APL-resistant patients.