Quantitative proteomics and RNA-sequencing of mouse liver endothelial cells identify novel regulators of BMP6 by iron

Allison L Fisher; Chia-Yu Wang; Yang Xu; Sydney Phillips; Joao A Paulo; Beata Małachowska; Xia Xiao; Wojciech Fendler; Joseph D Mancias; Jodie L Babitt

doi:10.1016/j.isci.2023.108555

Quantitative proteomics and RNA-sequencing of mouse liver endothelial cells identify novel regulators of BMP6 by iron

iScience. 2023 Nov 22;26(12):108555. doi: 10.1016/j.isci.2023.108555. eCollection 2023 Dec 15.

Authors

Allison L Fisher¹, Chia-Yu Wang¹, Yang Xu¹, Sydney Phillips¹, Joao A Paulo², Beata Małachowska^{3

4}, Xia Xiao¹, Wojciech Fendler^{3

5}, Joseph D Mancias⁵, Jodie L Babitt¹

Affiliations

¹ Nephrology Division and Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
² Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
³ Department of Biostatistics and Translational Medicine, Medical University of Lodz, Lodz, Poland.
⁴ Department of Radiation Oncology, Albert Einstein College of Medicine, NYC, NY, USA.
⁵ Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.

Abstract

Hepcidin is the master hormone governing systemic iron homeostasis. Iron regulates hepcidin by activating bone morphogenetic protein (BMP)6 expression in liver endothelial cells (LECs), but the mechanisms are incompletely understood. To address this, we performed proteomics and RNA-sequencing on LECs from iron-adequate and iron-loaded mice. Gene set enrichment analysis identified transcription factors activated by high iron, including Nrf-2, which was previously reported to contribute to BMP6 regulation, and c-Jun. Jun (encoding c-Jun) knockdown blocked Bmp6 but not Nrf-2 pathway induction by iron in LEC cultures. Chromatin immunoprecipitation of mouse livers showed iron-dependent c-Jun binding to predicted sites in Bmp6 regulatory regions. Finally, c-Jun inhibitor blunted induction of Bmp6 and hepcidin, but not Nrf-2 activity, in iron-loaded mice. However, Bmp6 and iron parameters were unchanged in endothelial Jun knockout mice. Our data suggest that c-Jun participates in iron-mediated BMP6 regulation independent of Nrf-2, though the mechanisms may be redundant and/or multifactorial.

Keywords: Integrative aspects of cell biology; Proteomics; Specialized functions of cells; Transcriptomics.

Abstract

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