Bone marrow adipose tissue: formation, function, and impact on health and disease

Bone marrow adipose tissue (MAT) accounts for up to 70% of human bone marrow volume and over 10% of total adipose mass in healthy adults. However, in contrast to other adipose depots, research into the formation and function of MAT has been relatively limited. Clinical studies have shown that bone marrow adiposity is altered in diverse disease states, including during osteoporosis and age-associated bone loss; type 1 diabetes; glucocorticoid therapy; hypertensive heart failure; and during anorexia nervosa and other states of caloric restriction. More recent studies suggest that MAT is increased in some obese patients and may decrease following bariatric surgery. Results from preclinical and clinical studies suggest that MAT has the potential to impact bone remodeling, hematopoiesis, and cancer metastasis to bone, as well as acting as an endocrine organ to exert systemic metabolic effects. Other recent published studies have revealed that adipocytes in MAT have developmental origins distinct to adipocytes in white adipose tissue (WAT). Together, these observations strongly suggest that MAT is developmentally and functionally distinct to WAT, and that MAT formation and function might have diverse effects on human health and disease.

In this Research Topic, we welcome authors to present novel findings related to the formation and function of MAT, both in the context of normal physiology and during disease states. Potential subjects include the following:

Basic MAT biology:
- Developmental origins of MAT
- Differences between MAT, WAT, and brown adipose tissue (BAT)
- Evolutionary function of MAT (i.e. whether MAT expansion confers a selective advantage during states of starvation)
- Impact of MAT on skeletal homeostasis
- Impact of MAT on metabolic homeostasis
- Impact of MAT on hematopoiesis
- Impact of MAT on immune function
- MAT as an endocrine organ
- Environmental determinants of MAT
- Insights from epidemiological studies

Role of MAT in disease pathogenesis
- MAT, osteoporosis, and skeletal health
- MAT and obesity/type 2 diabetes (including bariatric surgery/weight loss in obesity)
- MAT in type 1 diabetes
- MAT in anorexia nervosa
- MAT and metastatic bone disease
- MAT and ageing
- MAT and other diseases

Technical developments
- Model organisms for study of MAT
- Analysis of MAT in humans
- Techniques for MAT characterisation
- Genetic models of altered MAT formation: current strategies and future directions.

The goal of this Frontiers Research Topic is to present the state-of-the-art in our understanding of MAT biology, thereby laying a foundation for future research into this intriguing, clinically relevant tissue.