Bromodomain Inhibition Blocks Inflammation-Induced Cardiac Dysfunction and SARS-CoV2 Infection (preprint)

Cardiac injury and dysfunction occur in COVID-19 patients and increase the risk of mortality. Causes are ill defined, but could be direct cardiac infection and/or ‘cytokine-storm’ induced dysfunction. To identify mechanisms and discover cardio-protective drugs, we use a state-of-the-art pipeline combining human cardiac organoids with high throughput phosphoproteomics and single nuclei RNA sequencing. We identify that ‘cytokine-storm’ induced diastolic dysfunction can be caused by a cocktail of interferon gamma, interleukin 1β and poly(I:C) and also human COVID-19 serum. Bromodomain protein 4 (BRD4) is activated along with pathology driving fibrotic and induced nitric oxide synthase genes. BRD inhibitors fully recover function in hCO and totally prevent death in a cytokine-storm mouse model. BRD inhibition decreases transcription of multiple genes, including fibrotic, induced nitric oxide synthase and ACE2, and prevention of cardiac infection with SARS-CoV2. Thus, BRD inhibitors are promising candidates to prevent COVID-19 mediated cardiac damage.Funding: We acknowledge grant and fellowship support from the National Health and Medical Research Council of Australia (J.E.H., M.J.S., C.R.E., T.B.), Heart Foundation of Australia (J.E.H.), QIMR Berghofer Medical Research Institute (J.E.H.), The Stafford Fox Foundation (E.R.P.), the Royal Children’s Hospital Foundation (E.R.P.), Australian Research Council Strategic Initiative in Stem Cell Science (Stem Cells Australia) (E.R.P. and J.E.H.) and the Medical Research Future Fund (MRFF9200008) (J.E.H., T.B., M.J.S., K.P.A.MD., C.R.E., E.R.P.). M.J.S. is supported by Health and Medical Research Council of Australia Program (APP1132519) and Investigator (APP1173958) grants. A.S. is also supported by Investigator grant (APP1173880). The Murdoch Children’s Research Institute is supported by the Victorian Government’s Operational Infrastructure Support Program. This project received support from Dynomics Inc. J.E.H. is supported by a Snow Medical Fellowship. Conflict of Interest: R.J.M., J.E.H., G.A.Q.-R., D.M.T. and E.R.P. are listed as co-inventors on pending patents held by The University of Queensland and QIMR Berghofer Medical Research Institute that relate to cardiac organoid maturation and putative cardiac regeneration therapeutics. J.E.H. is a coinventor on licensed patents held by the University of Goettingen. R.J.M, E.R.P., D.M.T., B.G. and J.E.H. are co-founders, scientific advisors and stockholders in Dynomics Inc. D.M.T. and B.G. are employees of Dynomics Inc. /Dynomics Pty Ltd. QIMR Berghofer Medical Research Institute has filed a patent on the use of BRD inhibitors. Ethical Approval: Animal work was approved by the QIMR Berghofer Medical Research Institute Animal Ethics Committee. Ethical approval for the use of human embryonic stem cells (hESCs) was obtained from QIMR Berghofer’s Ethics Committee and was carried out in accordance with the National Health and Medical Research Council of Australia (NHMRC) regulations. Procedures complied with standards set under Australian guidelines for animal welfare and experiments were subject to Monash University animal welfare ethics review (Approval #MARP/2019/13606).

Discovery of drugs to treat cytokine storm-induced cardiac dysfunction using human cardiac organoids (preprint)

SARS-CoV2 infection leads to cardiac injury and dysfunction in 20-30% of hospitalized patients1 and higher rates of mortality in patients with pre-existing cardiovascular disease2,3. Inflammatory factors released as part of the cytokine storm are thought to play a critical role in cardiac dysfunction in severe COVID-19 patients4. Here we use human cardiac organoids combined with high sensitivity phosphoproteomics and single nuclei RNA sequencing to identify inflammatory targets inducing cardiac dysfunction. This state-of-the-art pipeline allowed rapid deconvolution of mechanisms and identification of putative therapeutics. We identify a novel interferon-{gamma} driven BRD4 (bromodomain protein 4)-fibrosis/iNOS axis as a key intracellular mediator of inflammation-induced cardiac dysfunction. This axis is therapeutically targetable using BRD4 inhibitors, which promoted full recovery of function in human cardiac organoids and prevented severe inflammation and death in a cytokine-storm mouse model. The BRD inhibitor INCB054329 was the most efficacious, and is a prime candidate for drug repurposing to attenuate cardiac dysfunction and improve COVID-19 mortality in humans.