Single-nucleus RNA sequencing reveals the pathological process and key transcription factor of sorafenib-induced cardiotoxicity

Sorafenib is a first-line treatment for advanced solid tumors. However, its clinical application is limited by cardiotoxicity. The underlying mechanisms remain unclear. We aimed to identify key mechanisms of sorafenib-induced cardiotoxicity using single-nucleus RNA sequencing (snRNA-seq) and experimental verification. SnRNA-seq was performed on cardiac tissue from a mouse model of sorafenib-induced cardiotoxicity. Bioinformatics analyses included weighted gene co-expression network analysis (WGCNA), differentially expressed gene (DEG) analysis, intercellular communication inference, and transcriptional regulatory network analysis. We conducted functional verification both in vivo and in vitro. SnRNA-seq demonstrated that cell clustering and component analysis confirmed the reduction in cardiomyocytes (CMs) and endothelial cells (ECs), along with an increase in immune cell populations. DEG enrichment analysis indicated that the upregulated DEGs in CMs, ECs, and fibroblasts (FBs) were consistently enriched in pathways associated with cardiomyopathy, whereas the downregulated DEGs were enriched in myocardial remodeling and repair processes. Gene set scoring revealed activation of fibrosis and inflammation programs in CMs and FBs. Cell communication analysis revealed a widespread disruption of cellular crosstalk in sorafenib-induced cardiotoxicity and identified key ligand-receptor pairs contributing to pro-inflammatory and pro-fibrotic phenotypes. Meanwhile we identified the common transcription factors and main effect genes in the three main effector cells during sorafenib-induced cardiotoxicity. Augur analysis and WGCNA consistently identified CMs as the most significantly affected cell type. Transcriptional regulatory network analysis highlighted melanocyte-inducing transcription factor (MITF) as a core transcription factor involved in sorafenib-induced cardiotoxicity. Functional validation showed that MITF expression was significantly increased in cardiac tissues and CMs after sorafenib treatment and that knockdown of MITF attenuated sorafenib-mediated CM hypertrophy in vitro. By constructing the first snRNA-seq data for sorafenib-induced cardiotoxicity, we identified MITF as a key transcription factor associated with sorafenib-induced cardiotoxicity. Our study provides potential therapeutic targets for mitigating sorafenib-induced cardiotoxicity.