Exosomes of endothelial progenitor cells repair injured vascular endothelial cells through the Bcl2/Bax/Caspase-3 pathway.

The main objective of this study is to evaluate the influence of exosomes derived from endothelial progenitor cells (EPC-Exo) on neointimal formation induced by balloon injury in rats. Furthermore, the study aims to investigate the potential of EPC-Exo to promote proliferation, migration, and anti-apoptotic effects of vascular endothelial cells (VECs) in vitro. The underlying mechanisms responsible for these observed effects will also be thoroughly explored and analyzed. Endothelial progenitor cells (EPCs) was isolated aseptically from Sprague-Dawley (SD) rats and cultured in complete medium. The cells were then identified using immunofluorescence and flow cytometry. The EPC-Exo were isolated and confirmed the identities by western-blot, transmission electron microscope, and nanoparticle analysis. The effects of EPC-Exo on the rat carotid artery balloon injury (BI) were detected by hematoxylin and eosin (H&E) staining, ELISA, immunohistochemistry, immunofluorescence, western-blot and qPCR. LPS was used to establish an oxidative damage model of VECs. The mechanism of EPC-Exo repairing injured vascular endothelial cells was detected by measuring the proliferation, migration, and tube function of VECs, actin cytoskeleton staining, TUNEL staining, immunofluorescence, western-blot and qPCR. In vivo, EPC-Exo exhibit inhibitory effects on neointima formation following carotid artery injury and reduce the levels of inflammatory factors, including TNF-α and IL-6. Additionally, EPC-Exo downregulate the expression of adhesion molecules on the injured vascular wall. Notably, EPC-Exo can adhere to the injured vascular area, promoting enhanced endothelial function and inhibiting vascular endothelial hyperplasia Moreover, they regulate the expression of proteins and genes associated with apoptosis, including B-cell lymphoma-2 (Bcl2), Bcl2-associated x (Bax), and Caspase-3. In vitro, experiments further confirmed that EPC-Exo treatment significantly enhances the proliferation, migration, and tube formation of VECs. Furthermore, EPC-Exo effectively attenuate lipopolysaccharides (LPS)-induced apoptosis of VECs and regulate the Bcl2/Bax/Caspase-3 signaling pathway. This study demonstrates that exosomes derived from EPCs have the ability to inhibit excessive carotid intimal hyperplasia after BI, promote the repair of endothelial cells in the area of intimal injury, and enhance endothelial function. The underlying mechanism involves the suppression of inflammation and anti-apoptotic effects. The fundamental mechanism for this anti-apoptotic effect involves the regulation of the Bcl2/Bax/Caspase-3 signaling pathway.

Glycoside combinations of Buyang Huanwu decoction ameliorate atherosclerosis via STAT3, HIF-1, and VEGF.

Buyang Huanwu decoction (BYHWD) is a classical traditional prescription. Glycosides are effective extracts of BYHWD, which have been proven to protect blood vessels and prevent atherosclerosis (AS). However, the mechanism of glycosides in inhibiting abnormal angiogenesis in atherosclerosis is still unclear. The specific amygdalin (AG), paeoniflorin (PF), and astragaloside IV (ASV) contents in the BYHWD-containing serum were detected using mass spectrometry. Network pharmacology and molecular docking are used to screen the targets of glycosides for treating atherosclerosis. The predicted targets were validated in an AS model of rat thoracic aortic endothelial cells (RTAEC) induced by oxidized low-density lipoprotein (ox-LDL). According to the mass spectrometry data, the specific contents of AG, PF, and ASV in the serum were 24.11 ng/ml, 20.94 ng/ml, and 69.87 ng/ml, respectively. Results of bioinformatics analysis show that signal transducer and activator of transcription (STAT)-3, hypoxia-inducible factor (HIF)-1, and vascular endothelial-derived growth factor (VEGF) may be involved in the treatment of AS with glycosides. The results of cell experiments revealed that glycoside combinations could treat atherosclerosis by inhibiting STAT3, HIF-1, and VEGF. AG, PF, and ASV are the effective ingredients of BYHWD. Glycoside combinations significantly ameliorate atherosclerosis by inhibiting STAT3, HIF-1, and VEGF.

Transplantation of Endothelial Progenitor Cells: Summary and prospect.

Endothelial Progenitor Cells (EPCs) are precursor cells of endothelial cells (ECs), which can differentiate into vascular ECs, protect from endothelial dysfunction and tissue ischemia, and reduce vascular hyperplasia. Due to these functions, EPCs are used as a candidate cell source for transplantation strategies. In recent years, a great progress was achieved in EPCs biology research, and EPCs transplantation has become a research hotspot. At present, transplanted EPCs have been used to treat ischemic diseases due to their powerful vasculogenesis and beneficial paracrine effects. Although EPCs transplantation has been proved to play an important role, the clinical application of EPCs still faces many challenges. This review briefly summarized the basic characteristics of EPCs, the process of EPCs transplantation promoting the healing of ischemic tissue, and the ways to improve the efficiency of EPCs transplantation. In addition, the application of EPCs in neurological improvement, cardiovascular and respiratory diseases and the challenges and problems in clinical application of EPCs were also discussed. In the end, the application of EPCs transplantation in regenerative medicine and tissue engineering was discussed.

Paracrine mechanisms of endothelial progenitor cells in vascular repair.

Endothelial progenitor cells (EPCs) play an important role in repairing damaged blood vessels and promoting neovascularization. However, the specific mechanism of EPCs promoting vascular repair is still unclear. Currently, there are two different views on the repair of damaged vessels by EPCs, one is that EPCs can directly differentiate into endothelial cells (ECs) and integrate into injured vessels, the other is that EPCs act on cells and blood vessels by releasing paracrine substances. But more evidence now supports the latter. Therefore, the paracrine mechanisms of EPCs are worth further study. This review describes the substances secreted by EPCs, some applications based on paracrine effects of EPCs, and the studies of paracrine mechanisms in cardiovascular diseases--all of these are to support the view that EPCs repair blood vessels through paracrine effects rather than integrating directly into damaged vessels.