Advances in Biological Function and Clinical Application of Small Extracellular Vesicle Membrane Proteins.

Defa Huang,Yongwei Xiao,Tianyu Zhong,Die Hu,Jianing Zhong,Jie Chen,Tong Yang,Zhengzhe Li,Yu Jiang,Xiaokang Zhang,Xiaoxing Wang,Fangfang Xie

doi:10.3389/fonc.2021.675940

Abstract

Small extracellular vesicles are membrane-bound vesicles secreted into extracellular spaces by virtually all types of cells. These carry a large number of membrane proteins on their surface that are incorporated during their biogenesis in cells. The composition of the membrane proteins hence bears the signature of the cells from which they originate. Recent studies have suggested that the proteins on these small extracellular vesicles can serve as biomarkers and target proteins for the diagnosis and treatment of diseases. This article classifies small extracellular vesicle membrane proteins and summarizes their pathophysiological functions in the diagnosis and treatment of diseases.

Highlights

Small extracellular vesicles are membrane-bound vesicular structures produced by the endosomal pathway and others independent of the endosomal pathway [1]
Tetraspanin proteins (CD81, CD63, etc.) and peripheral membrane proteins (Alix, etc.) participate in the sorting of sEV contents. These proteins are often used as the marker proteins of sEVs
Some sEV membrane proteins are closely related to development and progress of some cancers

Summary

Introduction

Small extracellular vesicles (sEVs) are membrane-bound vesicular structures produced by the endosomal pathway (exosomes) and others independent of the endosomal pathway [1]. Exosomes are defined as a subset of sEVs with a diameter of 30-200 nm and a density of 1.12-1.18 g/ml [2] These vesicles are found in a wide variety of body fluids, such as blood, urine, breast milk, ascites, amniotic fluid, saliva and cerebrospinal fluid [3,4,5]. They can be isolated and separated from other membrane-bound EVs through differential centrifugation, precipitation and immunoassays [6]. International Society for Extracellular Vesicles (ISEV) published the Minimal information for studies of extracellular vesicles 2018 (MISEV2018) [7] that recommend the use of “small EVs

Discussion

Conclusion