Recent Advances in Single-Cell Profiling and Multispecific Therapeutics: Paving the Way for a New Era of Precision Medicine Targeting Cardiac Fibroblasts

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

The complicated lives of GPCRs in cardiac fibroblasts

The role of different G protein-coupled receptors (GPCRs) in the cardiovascular system is well understood in cardiomyocytes and vascular smooth muscle cells (VSMCs). In the former, stimulation of Gs-coupled receptors leads to increases in contractility, while stimulation of Gq-coupled receptors modulates cellular survival and hypertrophic responses. In VSMCs, stimulation of GPCRs also modulates contractile and cell growth phenotypes. Here, we will focus on the relatively less well studied effects of GPCRs in cardiac fibroblasts, focusing on key signalling events involved in the activation and differentiation of these cells. We also review the hierarchy of signalling events driving the fibrotic response and the communications between fibroblasts and other cells in the heart. We discuss how such events may be distinct depending on where the GPCRs and their associated signalling machinery are localized in these cells with an emphasis on nuclear membrane-localized receptors. Finally, we explore what such connections between cell surface and nuclear GPCR signalling might mean for cardiac fibrosis.

Progress of Single-Cell RNA Sequencing Technology in Myocardial Infarction Research

After myocardial infarction, the heart enters a remodeling and repair phase that involves myocardial cell damage, inflammatory response, fibroblast activation, and, ultimately, angiogenesis. In this process, the proportions and functions of cardiomyocytes, immune cells, fibroblasts, endothelial cells, and other cells change. Identification of the potential differences in gene expression among cell types and/or transcriptome heterogeneity among cells of the same type greatly contribute to understanding the cellular changes that occur in heart and disease conditions. Recent advent of the single-cell transcriptome sequencing technology has facilitated the exploration of single cell diversity as well as comprehensive elucidation of the natural history and molecular mechanisms of myocardial infarction. In this manner, novel putative therapeutic targets for myocardial infarction treatment may be detected and clinically applied.