Identification of Novel Fibrosis Modifiers by In Vivo siRNA Silencing

Elisabeth H Vollmann; Lizhi Cao; Aldo Amatucci; Taylor Reynolds; Stefan Hamann; Isin Dalkilic-Liddle; Thomas O Cameron; Markus Hossbach; Kevin J Kauffman; Faryal F Mir; Daniel G Anderson; Tatiana Novobrantseva; Victor Koteliansky; Tatiana Kisseleva; David Brenner; Jeremy Duffield; Linda C Burkly

doi:10.1016/j.omtn.2017.04.014

Identification of Novel Fibrosis Modifiers by In Vivo siRNA Silencing

Mol Ther Nucleic Acids. 2017 Jun 16:7:314-323. doi: 10.1016/j.omtn.2017.04.014. Epub 2017 Apr 20.

Authors

Elisabeth H Vollmann¹, Lizhi Cao², Aldo Amatucci², Taylor Reynolds², Stefan Hamann², Isin Dalkilic-Liddle², Thomas O Cameron², Markus Hossbach³, Kevin J Kauffman⁴, Faryal F Mir⁴, Daniel G Anderson⁴, Tatiana Novobrantseva⁵, Victor Koteliansky⁶, Tatiana Kisseleva⁷, David Brenner⁷, Jeremy Duffield², Linda C Burkly²

Affiliations

¹ Biogen, Inc., Cambridge, MA 02142, USA. Electronic address: elisabeth.vollmann@biogen.com.
² Biogen, Inc., Cambridge, MA 02142, USA.
³ Axolabs, GmbH, 95326 Kulmbach, Germany.
⁴ David H. Koch Institute for Integrative Cancer Research, MIT, Cambridge, MA 02139, USA.
⁵ Verseau Therapeutics, Auburndale, MA 02466, USA.
⁶ Skolkovo Institute of Science and Technology, Moscow 143026, Russia.
⁷ Department of Medicine, University of California, San Diego, San Diego, CA 92093, USA.

Abstract

Fibrotic diseases contribute to 45% of deaths in the industrialized world, and therefore a better understanding of the pathophysiological mechanisms underlying tissue fibrosis is sorely needed. We aimed to identify novel modifiers of tissue fibrosis expressed by myofibroblasts and their progenitors in their disease microenvironment through RNA silencing in vivo. We leveraged novel biology, targeting genes upregulated during liver and kidney fibrosis in this cell lineage, and employed small interfering RNA (siRNA)-formulated lipid nanoparticles technology to silence these genes in carbon-tetrachloride-induced liver fibrosis in mice. We identified five genes, Egr2, Atp1a2, Fkbp10, Fstl1, and Has2, which modified fibrogenesis based on their silencing, resulting in reduced Col1a1 mRNA levels and collagen accumulation in the liver. These genes fell into different groups based on the effects of their silencing on a transcriptional mini-array and histological outcomes. Silencing of Egr2 had the broadest effects in vivo and also reduced fibrogenic gene expression in a human fibroblast cell line. Prior to our study, Egr2, Atp1a2, and Fkbp10 had not been functionally validated in fibrosis in vivo. Thus, our results provide a major advance over the existing knowledge of fibrogenic pathways. Our study is the first example of a targeted siRNA assay to identify novel fibrosis modifiers in vivo.

Keywords: Egr2; LNP; fibrosis; in vivo gene silencing; myofibroblast; siRNA.

Abstract

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