Adipose tissue macrophages as a therapeutic target in obesity‐associated diseases

Abstract

Summary Obesity is an increasing problem in developed and developing countries. Individuals with obesity have a higher risk of several diseases, such as cardiovascular disease, increased risk of insulin resistance, type 2 diabetes, infertility, degenerative disorders, and also certain types of cancer. Adipose tissue (AT) is considered an extremely active endocrine organ, and the expansion of AT is accompanied by the infiltration of different types of immune cells, which induces a state of low‐grade, chronic inflammation and metabolic dysregulation. Even though the exact mechanism of this low‐grade inflammation is not fully understood, there is clear evidence that AT‐infiltrating macrophages (ATMs) play a significant role in the pro‐inflammatory state and dysregulated metabolism. ATMs represent the most abundant class of leukocytes in AT, constituting 5% of the cells in AT in individuals with normal weight. However, this percentage dramatically increases up to 50% in individuals with obesity, suggesting an important role of ATMs in obesity and its associated complications. In this review, we discuss current knowledge of the function of ATMs during steady‐state and obesity and analyze its contribution to different obesity‐associated diseases, highlighting the potential therapeutic target of ATMs in these pathological conditions.

CIDEC: A Potential Factor in Diabetic Vascular Inflammation

“…For chronic systemic low-grade inflammation in type 2 diabetes, insulin resistance is to blame [16], which also promotes microinflammation [6] and macroinflammation [7], leading to the aggravation of cardiovascular complications [17]. We found that insulin resistance progressed gradually with the development of the disease, resulting in increased aortic IL-6 and IL-1β levels, which suggested that insulin resistance promoted aortic inflammation.…”

The Roles of Adipose Tissue Macrophages in Human Disease

“…M1 type ATMs are considered pro-inflammatory phenotypes in adipose tissue, and M2 type ATMs are considered anti-inflammatory phenotypes, but ATMs cannot be mechanically recognized in practice. A growing number of studies have shown that ATMs have multiple origins, with their functions spanning pure pro- or anti-inflammatory effects, and they are highly plastic and can achieve phenotypic transformation under specific circumstances, which can be therapeutic targets in the future ( 75 , 76 ).…”

cGAS/STING and innate brain inflammation following acute high-fat feeding

“…Specifically, a high-fat diet (HFD) in mice induces an inflammatory phenotype in microglia, the resident immune cells of the CNS (11,12). Additionally, HFD or other CNS pro-inflammatory events increase trafficking of peripheral immune cells into the brain (13)(14)(15), further promoting neuroinflammation.…”