Deciphering Adipose Tissue Extracellular Vesicles Protein Cargo and Its Role in Obesity.

Tamara Camino,Francisco Santos,Aurelio Martis-Sueiro,Iván Couto,Nerea Lago-Baameiro,María Pardo,Javier Baltar

doi:10.3390/ijms21249366

Abstract

The extracellular vesicles (EVs) have emerged as key players in metabolic disorders rising as an alternative way of paracrine/endocrine communication. In particular, in relation to adipose tissue (AT) secreted EVs, the current knowledge about its composition and function is still very limited. Nevertheless, those vesicles have been lately suggested as key players in AT communication at local level, and also with other metabolic peripheral and central organs participating in physiological homoeostasis, and also contributing to the metabolic deregulation related to obesity, diabetes, and associated comorbidities. The aim of this review is to summarize the most relevant data around the EVs secreted by adipose tissue, and especially in the context of obesity, focusing in its protein cargo. The description of the most frequent proteins identified in EVs shed by AT and its components, including their changes under pathological status, will give the reader a whole picture about the membrane/antigens, and intracellular proteins known so far, in an attempt to elucidate functional roles, and also suggesting biomarkers and new paths of therapeutic action.

Highlights

In the context of the alarming rise of obesity worldwide, there is an increasing interest to get a deeper knowledge about new signals secreted by adipose tissue at both healthy physiological and pathological status since energy imbalance causes an expansion of this tissue by hyperplasia and hypertrophy of adipocytes throughout the body
The role of extracellular vesicles (EVs) released by endocrine tissues, took certain time to emerge compared to other cellular systems such as in the immune system or in pathologies such as cancer; the development of investigations regarding EVs in the context of metabolic regulation has increased significantly in the last years
In this review we describe the protein content of EVs isolated from human and animal adipocytes in culture, from the stromal vascular fraction, and from whole adipose tissue paying special attention to those proteins elevated during the development of obesity

Summary

Introduction

In the context of the alarming rise of obesity worldwide, there is an increasing interest to get a deeper knowledge about new signals secreted by adipose tissue at both healthy physiological and pathological status since energy imbalance causes an expansion of this tissue by hyperplasia and hypertrophy of adipocytes throughout the body. The alteration on the secretion of these molecules is closely related to inflammation state, impaired adipocyte metabolism, and linked to obesity and its comorbidities. The whole picture of how adipokines and cytokines participate in obesity-related diseases and how these signaling molecules vary depending on the adipose tissue anatomical accumulation is still not clearly known. Given this scenario, other alternative ways of communication have been lately revealed for adipose tissue including non-classical secretion of proteins [3], release of extracellular vesicles [4], or long non-coding [5] and microRNAs [6] shedding that may travel free or inside the mentioned extracellular vesicles

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