Identifying collagen VI as a target of fibrotic diseases regulated by CREBBP/EP300

Abstract

Fibrotic diseases remain a major cause of morbidity and mortality, yet there are few effective therapies. The underlying pathology of all fibrotic conditions is the activity of myofibroblasts. Using cells from freshly excised disease tissue from patients with Dupuytren’s disease (DD), a localized fibrotic disorder of the palm, we sought to identify new therapeutic targets for fibrotic disease. We hypothesized that the persistent activity of myofibroblasts in fibrotic diseases might involve epigenetic modifications. Using a validated genetics-led target prioritization algorithm (Pi) of genome wide association studies (GWAS) data and a broad screen of epigenetic inhibitors, we found that the acetyltransferase CREBBP/EP300 is a major regulator of contractility and extracellular matrix production via control of H3K27 acetylation at the profibrotic genes, ACTA2 and COL1A1. Genomic analysis revealed that EP300 is highly enriched at enhancers associated with genes involved in multiple profibrotic pathways, and broad transcriptomic and proteomic profiling of CREBBP/EP300 inhibition by the chemical probe SGC-CBP30 identified collagen VI (Col VI) as a prominent downstream regulator of myofibroblast activity. Targeted Col VI knockdown results in significant decrease in profibrotic functions, including myofibroblast contractile force, extracellular matrix (ECM) production, chemotaxis, and wound healing. Further evidence for Col VI as a major determinant of fibrosis is its abundant expression within Dupuytren’s nodules and also in the fibrotic foci of idiopathic pulmonary fibrosis (IPF). Thus, Col VI may represent a tractable therapeutic target across a range of fibrotic disorders.

Collagen VI as a driver and disease biomarker in human fibrosis

“…BRD4 also marks the TSS within both promoters, again with elevated levels of H3K27 acetylation reflecting high levels of active transcription of these genes. We also performed EP300 Chip-Seq de novo motif analysis of the EP300-enriched loci and identified known consensus binding sequences for the transcription factor Fra-1/FOSL1 and subsequently confirmed a role of this TF in COL6A3 gene expression [107]. Further evidence supporting a direct role of this transcription family in the regulation of collagen VI gene expression was recently described by Ucero et al [109].…”

Identification of an Altered Matrix Signature in Kidney Aging and Disease

“…Therefore collagen VI deposition in ageing and disease may occur to restore the mechanical properties of the GBM. Furthermore, collagen VI is a prominent downstream regulator of myofibroblast activity, with knockdown reducing fibrosis (46). Our data shows collagen VI increasing early where it may act to strengthen BM defects while paradoxically promoting fibrosis (Figure 8E).…”

Epigenetic Modulation of Radiation-Induced Diacylglycerol Kinase Alpha Expression Prevents Pro-Fibrotic Fibroblast Response

“…The compound has been suggested to reduce fibrosis because it either directly or together with an inhibitor of the main collagen receptor discoidin domain receptor 1 (DDR1) attenuated lung inflammation and fibroblast activation in idiopathic pulmonary fibrosis [ 81 , 87 ]. In addition, a transcriptome analysis found that multiple pro-fibrotic pathways were dysregulated in CBP30-treated myofibroblasts derived from patients with Dupuytren’s disease [ 88 ]. As to be expected, CBP30 reduced the overall H3K27ac level and the radiation-induced expression of DGKA and collagens in BJ fibroblasts.…”