1. A transcriptional switch governs fibroblast activation in heart disease
- Author
-
Alexanian, Michael, Przytycki, Pawel F., Micheletti, Rudi, Padmanabhan, Arun, Ye, Lin, Travers, Joshua G., Gonzalez-Teran, Barbara, Silva, Ana Catarina, Duan, Qiming, Ranade, Sanjeev S., Felix, Franco, Linares-Saldana, Ricardo, Lee, Clara Youngna, Sadagopan, Nandhini, Pelonero, Angela, Huang, Yu, and Andreoletti, Gaia
- Subjects
Heart diseases -- Development and progression -- Genetic aspects ,Fibroblasts -- Genetic aspects -- Health aspects ,Genetic regulation -- Health aspects ,Genetic transcription -- Health aspects ,Environmental issues ,Science and technology ,Zoology and wildlife conservation - Abstract
In diseased organs, stress-activated signalling cascades alter chromatin, thereby triggering maladaptive cell state transitions. Fibroblast activation is a common stress response in tissues that worsens lung, liver, kidney and heart disease, yet its mechanistic basis remains unclear.sup.1,2. Pharmacological inhibition of bromodomain and extra-terminal domain (BET) proteins alleviates cardiac dysfunction.sup.3-7, providing a tool to interrogate and modulate cardiac cell states as a potential therapeutic approach. Here we use single-cell epigenomic analyses of hearts dynamically exposed to BET inhibitors to reveal a reversible transcriptional switch that underlies the activation of fibroblasts. Resident cardiac fibroblasts demonstrated robust toggling between the quiescent and activated state in a manner directly correlating with BET inhibitor exposure and cardiac function. Single-cell chromatin accessibility revealed previously undescribed DNA elements, the accessibility of which dynamically correlated with cardiac performance. Among the most dynamic elements was an enhancer that regulated the transcription factor MEOX1, which was specifically expressed in activated fibroblasts, occupied putative regulatory elements of a broad fibrotic gene program and was required for TGF[beta]-induced fibroblast activation. Selective CRISPR inhibition of the single most dynamic cis-element within the enhancer blocked TGF[beta]-induced Meox1 activation. We identify MEOX1 as a central regulator of fibroblast activation associated with cardiac dysfunction and demonstrate its upregulation after activation of human lung, liver and kidney fibroblasts. The plasticity and specificity of BET-dependent regulation of MEOX1 in tissue fibroblasts provide previously unknown trans- and cis-targets for treating fibrotic disease. BET proteins regulate a reversible transcriptional switch that governs fibroblast activation in heart disease through the transcription factor MEOX1., Author(s): Michael Alexanian [sup.1] , Pawel F. Przytycki [sup.1] , Rudi Micheletti [sup.2] , Arun Padmanabhan [sup.1] [sup.3] , Lin Ye [sup.1] , Joshua G. Travers [sup.4] , Barbara Gonzalez-Teran [...]
- Published
- 2021
- Full Text
- View/download PDF