Phenotypic Screening Uncovered Anti-Myocardial Fibrosis Candidates Using a Novel 3D Myocardial Tissue Under Hypoxia

Myocardial fibrosis (MF) is a shared hallmark among cardiovascular diseases, reflecting a common thread in their pathogenesis. However, reliable MF models simulating the pathogenesis are limited, which leads to the urgent need for more efficient drugs targeting MF. Herein, a novel contractile three-dimensional (3D) myocardial tissue model integrating cardiomyocytes (CMs), cardiac-fibroblasts (CFs), and bone-marrow-derived macrophages (BMDMs) in collagen hydrogel was developed to simulate the clinical pathological changes of terminal stage of cardiovascular disease, heart failure, and screen compounds with anti-MF activity dependably. The 3D myocardial tissue model demonstrated precise, visualizable, and quantifiable contractile characteristics under hypoxia and drug interventions. 76 compounds extracted from the resins of T.vernicifluum, a traditional Chinese medicine with clear clinical benefits for fibrotic diseases, were screened for anti-fibrotic activity. Following the in vitro assay using 3D oxygen-glucose deprivation (OGD)-treated myocardial tissue model instead of two-dimensional (2D) transforming growth factor-ß (TGF-ß)-treated CFs model, two candidates including LQ-40 and SQ-3 exerts impressive anti-MF activity, which was further validated in left anterior descending coronary artery (LAD)-MF mouse model. The current results demonstrate the feasibility and advantage of the novel 3D contractile multicellular types model in the discovery of potential drugs for MF, and candidates with promising potential for MF. Overall design: To investigate the interactions between the three cell types, 3D-OGD-MF and three types of 2D cells at a ratio of 1:1:1 were subjected to RNA-seq. To accurately assess the effects of LQ-40 and SQ3 on myocardial fibrosis, and investigate the potential anti-fibrotic mechanism behind structural similarity, we performed mRNA-Seq analysis on mouse myocardial tissue in sham, model, LQ-40 and SQ-3 groups in triplicate