RESUMO
Resumen La obesidad es una enfermedad crónica, no transmisible, que recientemente ha tenido una connotación especial debido al aumento de su prevalencia en países en vía de desarrollo. Este incremento está relacionado con un aumento en la aparición de enfermedades metabólicas y el riesgo cardiovascular. Si bien la prevalencia de obesidad está aumentando en todos los países del mundo, existen diferencias regionales tanto en la prevalencia como en las tendencias de la obesidad. Por consiguiente, comprender los impulsores de estas diferencias regionales podría ayudar a proporcionar orientación para las estrategias de intervención más prometedoras. A pesar de considerarse una eventualidad simple en una proporción de lo que se ingiere y lo que se gasta, existen muchos factores que regulan esta enfermedad. No es sencillo encontrar medidas terapéuticas para la obesidad, pues sus causas son múltiples. En forma reciente, ha despertado un especial interés la caracterización funcional de los adipocitos, específicamente de los adipocitos beige, dado que su función está íntimamente relacionada con las circunstancias externas del ambiente y tienen una flexibilidad que les permite producir energía y mejorar muchos de los parámetros metabólicos en los individuos. En este manuscrito se hará énfasis en las características de las células adiposas y su influencia en el riesgo cardiovascular.
Abstract Obesity is a chronic non-transmissible disease that has recently had a special connotation due to the increase of its prevalence in developing countries. The increase in obesity is related to an expansion in the appearance of metabolic diseases and cardiovascular risk. Although the prevalence of obesity is increasing in all countries of the world, there are regional differences in both the prevalence and trends of obesity. Therefore, understanding the circumstances of these regional differences could help provide guidance for the most promising intervention strategies. Despite being considered a simple outcome in a proportion of what is ingested and what is spent, there are many factors that regulate this disease. It is not easy to find therapeutic measures for obesity, because their causes are multiple. Recently, the functional characterization of adipocytes, especially Beige adipocytes, has been of particular interest since their function is intimately related to the external circumstances of the environment and they have a flexibility that allows them to produce energy and improve many of the metabolic parameters in individuals. In the present manuscript we will focus on the characteristics of fat cells and their influence on cardiovascular risk.
Assuntos
Obesidade , Adipócitos Marrons , Adipócitos Brancos , Adipócitos Bege , Fatores de Risco de Doenças CardíacasRESUMO
Adipose tissue is the largest endocrine organ in humans and has an important influence on many physiological processes throughout life. An increasing number of studies have described the different phenotypic characteristics of fat cells in adults. Perhaps one of the most important properties of fat cells is their ability to adapt to different environmental and nutritional conditions. Hypothalamic neural circuits receive peripheral signals from temperature, physical activity or nutrients and stimulate the metabolism of white fat cells. During this process, changes in lipid inclusion occur, and the number of mitochondria increases, giving these cells functional properties similar to those of brown fat cells. Recently, beige fat cells have been studied for their potential role in the regulation of obesity and insulin resistance. In this context, it is important to understand the embryonic origin of beige adipocytes, the response of adipocyte to environmental changes or modifications within the body and their ability to transdifferentiate to elucidate the roles of these cells for their potential use in therapeutic strategies for obesity and metabolic diseases. In this review, we discuss the origins of the different fat cells and the possible therapeutic properties of beige fat cells.
RESUMO
Excess adipose tissue is considered one of the main causes of metabolic and cardiovascular diseases. Initially, the adipose tissue was considered the main lipid and energy storage of the organism. Subsequently it was discovered that adipose tissue had other functions such as endocrine, controlling different metabolic and immune processes. Currently, different types of adipose tissue are recognized. The white adipocyte represents the main energy reserve, on the contrary the brown adipocyte is responsible for the oxidation of lipids for thermogenesis. The beige adipocyte originates from the white adipocyte, by a process known as "browning", which leads to lipolysis and thermogenesis. The 3 previous types have recently joined the blue adipocyte, which has a role in liver retinoid homeostasis and the pink adipocyte that participates in lactogenesis and is present in the mammary gland of animals; its role is still unknown in humans. The newly identified hormone Irisin is secreted by the skeletal muscle and promotes browning of white to beige adipose tissue, thus favoring thermogenesis. Another interesting aspect of this hormone is that it represents a connection between muscle activity and lipolysis. The above suggests that Irisin may be the key in the prevention and treatment of obesity.
El exceso de tejido adiposo representa una de las principales causas de las enfermedades metabólicas y cardiovasculares. Inicialmente al tejido adiposo se le consideró el almacén de lípidos y energía del organismo. Posteriormente se descubrió que presentaba otras funciones, como la endocrina, controlando diferentes procesos metabólicos e inmunitarios. Por sus características funcionales y estructurales, se reconocen varios tipos de tejido adiposo. El adipocito blanco representa la reserva energética y el adipocito marrón se encarga de la oxidación de los lípidos para la termogénesis. El adipocito beige se origina del adipocito blanco, mediante un proceso que conduce a la lipólisis y la termogénesis. A los anteriores se han sumado el adipocito azul, en el hígado, que interviene en la homeostasis de retinoides, y el adipocito rosa, que participa en la lactogénesis y se ha identificado en la glándula mamaria de animales. La irisina es una hormona secretada principalmente por el músculo esquelético, que promueve el pardeamiento del tejido adiposo blanco a beige, favoreciendo así la termogénesis. Otro aspecto interesante de esta hormona es que representa una conexión entre la actividad muscular y la lipólisis. Por lo anterior, la irisina puede ser una clave en la prevención y el tratamiento de la obesidad.