Immunometabolism is a current issue that has shown relevance in recent years, because the way we understand the adipose tissue has shifted from simply being a site of energy storage to a very active endocrine organ, which dysregulation has a major impact on other systems, especially on the immune one. Understanding the molecular basis of the regulation of adipose tissue is essential to look for alternatives in the treatment and prognosis of obesity in future generations. In this regard, it is described that the immune system has great importance in physiological processes of adipose tissue and vice versa. The main objective of this chapter is to describe the relationship between the immune system and metabolism, emphasizing dysregulation when obesity is present. Upon completion of this chapter, the reader will be able to understand the relationship between the immune system and metabolism, in normal and obesity states; also, will identify the chronic state of low-grade inflammation as the main etiological factor of obesity co-morbidities, such as insulin resistance, diabetes mellitus, osteoarthritis and susceptibility to some kinds of cancer, among others.
Part of the book: Adiposity
Obesity, being an epidemy these days, is the trigger of metabolic disturbances such as cardiovascular disease, type 2 diabetes, and insulin resistance. Defined as an increase in fat storage, adipose tissue has been put under the spotlight as the culprit of these conditions, as it is composed not only by adipocytes but of any immune system cell and a singular extracellular matrix. Its behavior under acute and chronic hypercaloric states is quite different; persistent hypertrophy in the latter creates hypoxia, resulting in the release of reactive oxygen species and proinflammatory cytokines that impact on the immune response type of the resident leucocytes, mainly macrophages. Hypertrophy over hyperplasia, adipose tissue macrophages-M1 phenotype polarization, and the adipokines/myokines profile are thought to be regulated by foreign microRNAs, delivered from surrounding or distant cells by exosomes through the bloodstream. In this chapter, we focus on adipose tissue immunometabolism and how obesity causes the chronic inflammatory state, and, subsequently, this stablishes a pathologic adiposity, characterized by dyslipidemia and insulin resistance (IR).
Part of the book: Obesity