Simvastatin Attenuates Cardiac Fibrosis via Regulation of Cardiomyocyte-Derived Exosome Secretion

Abstract

Exosome-mediated communication within the cardiac microenvironment is associated with cardiac fibrosis. Simvastatin (SIM), a potent statin, protects against cardiac fibrosis, but its mechanism of action is unclear. We investigated the inhibitory effects and underlying mechanism of simvastatin in cardiac fibrosis, by regulating exosome-mediated communication. Male Sprague-Dawley rats were treated with angiotensin (Ang) II alone, or with SIM for 28 d. Cardiac fibrosis, expressions of fibrosis-associated proteins and mRNAs, and collagen fiber arrangement and deposition were examined. Protein expressions in exosomes isolated from Ang II-treated cardiomyocytes (CMs) were evaluated using nano-ultra-performance liquid chromatographic system, combined with tandem mass spectrometry. Transformation of fibroblasts to myofibroblasts was evaluated using scanning electron and confocal microscopy, and migration assays. Our results showed that SIM attenuated in vivo expression of collagen and collagen-associated protein, as well as collagen deposition, and cardiac fibrosis. The statin also upregulated decorin and downregulated periostin in CM-derived exosomes. Furthermore, it suppressed Ang II-induced transformation of fibroblast to myofibroblast, as well as fibroblast migration. Exosome-mediated cell-cell communication within the cardiac tissue critically regulated cardiac fibrosis. Specifically, SIM regulated the release of CM exosomes, and attenuated Ang II-induced cardiac fibrosis, highlighting its potential as a novel therapy for cardiac fibrosis.

Cardiomyocyte-Derived Exosomes: Biological Functions and Potential Therapeutic Implications

“…The tetraspanins CD9 and CD81 are also molecular markers of cardiomyocyte-derived exosomes (Wang et al, 2014; Garcia et al, 2015; Yang et al, 2018). Moreover, Hsp70 is a specific marker of cardiomyocyte-derived exosomes, and can be identified by western blotting (Kuo et al, 2019). However, exosomes formed through ESCRT-independent pathways are usually devoid of biomarkers associated with the ESCRT complex, such as CD63 or CD9 (Akers et al, 2013).…”

“…However, exosomes formed through ESCRT-independent pathways are usually devoid of biomarkers associated with the ESCRT complex, such as CD63 or CD9 (Akers et al, 2013). To rule out the contamination of other membrane vesicle populations, researchers have often performed the simultaneous detection of endoplasmic reticulum-related markers such as calnexin and glucose-regulated protein 78 (Grp78) (Gennebäck et al, 2013; Kuo et al, 2019).…”

“…It should be noted that the presence and relative abundance of biomolecules inside or on the surface of exosomes can fluctuate depending on the cell type and pathophysiological state (Zhou et al, 2006; Cosme et al, 2017; da Silva Novaes et al, 2019). Recently, Kuo et al (2019) reported that simvastatin, a potent competitive inhibitor of 5-hydroxy-3-methylglutaryl-coenzyme A reductase, attenuated collagen-associated protein expression in cardiomyocyte-derived exosomes and reduced the uptake of the exosomes by human cardiac fibroblasts. Yang et al (2018) also found that, in a rat model of cardiac fibrosis, miR-208a levels were up-regulated in cardiomyocyte-derived exosomes.…”

Thrombospondin 1‐induced exosomal proteins attenuate hypoxia‐induced paraptosis in corneal epithelial cells and promote wound healing

“…Cell tracking was performed as described in our previous study. 25 Briefly, cell image sequences were captured every 15 minutes in the microscope with different magnifications according to the cell size and field of view. We used ImageJ/ FIJI software (National Institutes of Health, Bethesda, MD, USA) to locate the positions of cells in every image frame.…”

Roles and Clinical Applications of Exosomes in Cardiovascular Disease

“…Injection into the ischemic myocardium of exosomes derived from endothelial cells stimulated by shock wave therapy decreases myocardial fibrosis [27]. Simvastatin significantly attenuates collagen deposition and cardiac fibrosis in rats treated with Ang II, which appears secondary to simvastatin-mediated induction of decorin and reduction of periostin in Ang II-treated cardiomyocytederived exosomes [35].…”