Bone marrow adipose tissue: a novel regulator of cardiometabolic health?

Bone marrow adipose tissue: a novel regulator of cardiometabolic health?

Obesity is a major risk factor for cardiovascular disease and numerous other pathologies. Given that obesity is defined by excessive adiposity, this health burden has motivated extensive research into the formation and function of white adipose tissue (WAT; Figure 1). Such research has revealed that WAT is a key regulator of metabolic health, both as a site for energy storage and as a major endocrine organ. More recently, there has been intense interest in brown adipose tissue (BAT), which might be a new target for treating obesity and related diseases (Figure 1). However, few people realise that adipocytes are also a major component of the bone marrow. Indeed, such bone marrow adipose tissue (MAT) accounts for up to 70% of bone marrow volume in lean, healthy adults, corresponding to over 10% of total fat mass (Figure 1). It is therefore striking that, compared to WAT and BAT, study of MAT has been extremely limited (Figure 1). Thus, the function of MAT remains largely unknown. Our previous research, published in Cell Metabolism, revealed that, like WAT, MAT is an endocrine organ that might influence cardiometabolic health. We are now building on this groundbreaking finding by further addressing the impact of MAT on human health and disease.

 

Figure1. Limited study of MAT, despite it being a major adipose depot.

Our current research focuses on the formation and function of MAT in conditions of caloric restriction (CR): in striking contrast to WAT, MAT accumulates during CR in animals and humans, but the reasons for this have not been determined (Figure 2). CR is associated with numerous health benefits, including increased lifespan, healthy ageing, and decreased risk of cancer and cardiometabolic diseases. However, CR can also have negative consequences, such as bone loss and impaired immune function. Therefore, we are currently investigating if increased MAT contributes to these diverse effects of CR. Our aim is to establish the function of MAT in normal physiology, and whether MAT might be a novel therapeutic target for cardiometabolic or other diseases.

 

Figure 2. Unlike WAT, MAT accumulates during caloric restriction, but the reasons for this remain to be determined.

Figure 3. 3D video reconstruction of a mouse tibia, showing MAT distribution