Common Injuries and Repair Mechanisms in the Endothelial Lining

Abstract

Objective: Endothelial cells (ECs) are important metabolic and endocrinal organs which play a significant role in regulating vascular function. Vascular ECs, located between the blood and vascular tissues, can not only complete the metabolism of blood and interstitial fluid but also synthesize and secrete a variety of biologically active substances to maintain vascular tension and keep a normal flow of blood and long-term patency. Therefore, this article presents a systematic review of common injuries and healing mechanisms for the vascular endothelium.

Data sources: An extensive search in the PubMed database was undertaken, focusing on research published after 2003 with keywords including endothelium, vascular, wounds and injuries, and wound healing.

Study selection: Several types of articles, including original studies and literature reviews, were identified and reviewed to summarize common injury and repair processes of the endothelial lining.

Results: Endothelial injury is closely related to the development of multiple cardiovascular and cerebrovascular diseases. However, the mechanism of vascular endothelial injury is not fully understood. Numerous studies have shown that the mechanisms of EC injury mainly involve inflammatory reactions, physical stimulation, chemical poisons, concurrency of related diseases, and molecular changes. Endothelial progenitor cells play an important role during the process of endothelial repair after such injuries. What's more, a variety of restorative cells, changes in cytokines and molecules, chemical drugs, certain RNAs, regulation of blood pressure, and physical fitness training protect the endothelial lining by reducing the inducing factors, inhibiting inflammation and oxidative stress reactions, and delaying endothelial caducity.

Conclusions: ECs are always in the process of being damaged. Several therapeutic targets and drugs were seeked to protect the endothelium and promote repair.

Keywords: Endothelium; Vascular; Wound Healing; Wounds and Injuries.

Figure 1

The diagrammatic drawing in regard to the injury and repair in the common status of endothelial lining. →: Promote; (-): Inhibition. EC: Endothelial cells; EPCs: Endothelial progenitor cells; EMS: Electric muscle stimulation; HSCs: Hematopoietic stem cells; ECFCs: Endothelial colony forming cells; EOCs: Early outgrowth cells; NO: Nitric oxide; hAECs: Human amniotic epithelial cells; ADSCs: Adipose-derived stem cells; Tang: Angiogenic T cells; HBMP–2: Human bone morphogenic protein-2; MSCs: Mesenchymal stromal cells; eNOS: Endothelial nitric oxide synthase; apoA-I: Apolipoprotein A-I; HO-1: Heme oxygenase-1; ZFP580: Zinc finger transcription factor; H₂O₂: Hydrogen peroxide; IL-8: Interleukin-6; TNF: Tumor necrosis factor; sCD40L: Soluble CD40 ligand; MCP-1: Monocyte chemoattractant protein-1; IL-6: Interleukin-6; ZnO: Zinc oxide; VEGFR2: Vascular endothelial growth factor receptor 2; CXCR4: CXC chemokine receptor 4; s-ICAM1: Soluble intercellular adhesion molecule 1; ROS: Reactive oxygen species; NADPH: Nicotinamide adenine dinucleotide phosphate; MnSOD: Manganese superoxide dismutase.