Rhein, a novel Histone Deacetylase (HDAC) inhibitor with antifibrotic potency in human myocardial fibrosis

David Monteiro Barbosa,David Monteiro Barbosa,David Monteiro Barbosa,Sonja Hartwig,Sonja Hartwig,Sonja Hartwig,Daniella Herzfeld De Wiza,Daniella Herzfeld De Wiza,Daniella Herzfeld De Wiza,Jorg Kotzka,Hadi Al-Hasani,Hadi Al-Hasani,Hadi Al-Hasani,Ulrike Kettel,Ulrike Kettel,Ulrike Kettel,Stefan Lehr,Stefan Lehr,Stefan Lehr,D Margriet Ouwens,Martina Krüger,Sylvia Jacob,Pia Fahlbusch,Pia Fahlbusch,Pia Fahlbusch,Birgit Knebel,Birgit Knebel,Birgit Knebel

doi:10.1038/s41598-020-61886-3

Abstract

Although fibrosis depicts a reparative mechanism, maladaptation of the heart due to excessive production of extracellular matrix accelerates cardiac dysfunction. The anthraquinone Rhein was examined for its anti-fibrotic potency to mitigate cardiac fibroblast-to-myofibroblast transition (FMT). Primary human ventricular cardiac fibroblasts were subjected to hypoxia and characterized with proteomics, transcriptomics and cell functional techniques. Knowledge based analyses of the omics data revealed a modulation of fibrosis-associated pathways and cell cycle due to Rhein administration during hypoxia, whereas p53 and p21 were identified as upstream regulators involved in the manifestation of cardiac fibroblast phenotypes. Mechanistically, Rhein acts inhibitory on HDAC classes I/II as enzymatic inhibitor. Rhein-mediated cellular effects were linked to the histone deacetylase (HDAC)-dependent protein stabilization of p53 under normoxic but not hypoxic conditions. Functionally, Rhein inhibited collagen contraction, indicating anti-fibrotic property in cardiac remodeling. This was accompanied by increased abundance of SMAD7, but not SMAD2/3, and consistently SMAD-specific E3 ubiquitin ligase SMURF2. In conclusion, this study identifies Rhein as a novel potent direct HDAC inhibitor that may contribute to the treatment of cardiac fibrosis as anti-fibrotic agent. As readily available drug with approved safety, Rhein constitutes a promising potential therapeutic approach in the supplemental and protective intervention of cardiac fibrosis.

Highlights

Heart failure (HF) accounts for the most deaths in both first- as well as third-world countries[1]
The hypoxic treatment protocol was monitored by analyses of hypoxia marker HIF1α and its direct transcriptional downstream target GLUT1, which revealed an approximate 6-fold increased protein abundance and 5-fold increased transcription in hypoxia exposed cells (Fig. 1B,C), respectively
Rhein treatment showed an overall reduction in the expression of exemplary pro-fibrotic response targets (Supplementary Fig. 2A; ACTA2, CTGF, COL1A1, COL3A1, OGN, ITGA8, TIMP3) and increased MMP1 expression pointing towards a higher MMP:TIMP ratio

Summary

Introduction

Heart failure (HF) accounts for the most deaths in both first- as well as third-world countries[1]. During cardiac fibrosis an imbalance between extracellular matrix (ECM) turnover and synthesis results in the formation of excess fibrous connective tissue[3]. This accumulation of ECM in the left ventricle is directly associated with increased mechanical stiffness, contributing to both systolic and diastolic dysfunction[4]. Chronic or prolonged periods of hypoxia have been hypothesized to be involved in adverse fibrosis, directly associated to changes of fibroblast behavior and modulation of secreted soluble factors i.e. VEGF or TGFβ by CFs8,11,12. The role of Rhein in cardiac pathology has been scarcely investigated, yet one study reported that administration of its pro-drug form Diacerein improved left ventricular remodeling and cardiac function after myocardial infarction in rats[18]. In this study the effect of Rhein administration on FMT of hypoxia-treated primary human ventricular cardiac fibroblasts (HCF-v) was investigated

Objectives

Methods

Results

Conclusion