Distinct Shades of Adipocytes Control the Metabolic Roles of Adipose Tissues: From Their Origins to Their Relevance for Medical Applications

Abstract

Adipose tissue resides in specific depots scattered in peripheral or deeper locations all over the body and it enwraps most of the organs. This tissue is always in a dynamic evolution as it must adapt to the metabolic demand and constraints. It exhibits also endocrine functions important to regulate energy homeostasis. This complex organ is composed of depots able to produce opposite functions to monitor energy: the so called white adipose tissue acts to store energy as triglycerides preventing ectopic fat deposition while the brown adipose depots dissipate it. It is composed of many cell types. Different types of adipocytes constitute the mature cells specialized to store or burn energy. Immature adipose progenitors (AP) presenting stem cells properties contribute not only to the maintenance but also to the expansion of this tissue as observed in overweight or obese individuals. They display a high regeneration potential offering a great interest for cell therapy. In this review, we will depict the attributes of the distinct types of adipocytes and their contribution to the function and metabolic features of adipose tissue. We will examine the specific role and properties of distinct depots according to their location. We will consider their cellular heterogeneity to present an updated picture of this sophisticated tissue. We will also introduce new trends pointing out a rational targeting of adipose tissue for medical applications.

The Value of Serum Adiponectin in Osteoporotic Women: Does Weight Have an Effect?

“…Higher adipose tissue reflected by increased BMI serves as an estrogen supply for women in menopause, and it seems to suppress osteoclast bone resorption. Interestingly, this defensive action will be missed if BMI surged into obesity, which explains the controversy in earlier research [ 9 ].…”

“…As a result, there is a rising interest in bone marrow adipocytes as a targeted therapy for osteoporosis [ 8 ]. In addition, adiponectin receptors were described in osteoblasts, implying their role in bone formation by promoting proliferation and differentiation of osteoblast and inhibiting osteoclasts activity [ 9 ].…”

Dysregulated Epicardial Adipose Tissue as a Risk Factor and Potential Therapeutic Target of Heart Failure with Preserved Ejection Fraction in Diabetes

“…Animal and human data indicate that EAT is phenotypically brown during the early stages of life. Despite whitening with age, it retains in adulthood the biological property to combust proinflammatory FAs, showing molecular features and a gene profile of beige adipocytes, a new class of adipocytes that display the properties of brown adipocytes, but are located within WAT depots [ 24 , 37 ]. In a study on fat samples taken at open heart surgery, the expression of uncoupling protein-1 (UCP-1), the inner mitochondrial membrane protein that is a specific marker for and a mediator of nonshivering thermogenesis in brown adipocytes, was 5-fold higher in epicardial than substernal fat and basically undetectable in SAT [ 38 ].…”

The Relationship of Epicardial Adipose Tissue and Cardiovascular Disease in Chronic Kidney Disease and Hemodialysis Patients

“…In human and animal experiments, it has been determined that EAT exhibits predominantly brown adipose tissue characteristics in the early stages of life. Although white adipose tissue features dominate EAT with age, it is known that beige adipocytes, a new class of adipocyte with brown adipocyte tissue features, also exhibit their molecular and biological features in adulthood [ 16 ]. These inflammatory and anti-inflammatory events are attributed to EAT-secreted substances such as adinopectin, leptin, omentin-1, nitric oxide, and angiotensinogen, which have both autocrine and paracrine effects [ 17 ].…”