Bone marrow adiposity: basic and clinical implications

Sebo ZL, Rendina-Ruedy E, Ables GP, Lindskog DM, Rodeheffer MS, Fazeli PK, Horowitz MC.

Endocr Rev. 2019 Oct 1;40(5):1187-1206

PMID: 31127816

The presence of adipocytes in mammalian bone marrow (BM) has been recognized histologically for decades, yet, until recently, these cells have received little attention from the research community. Advancements in mouse transgenics and imaging methods, particularly in the last 10 years, have permitted more detailed examinations of marrow adipocytes than ever before and yielded data that show these cells are critical regulators of the BM microenvironment and whole-body metabolism. Indeed, marrow adipocytes are anatomically and functionally separate from brown, beige, and classic white adipocytes. Thus, areas of BM space populated by adipocytes can be considered distinct fat depots and are collectively referred to as marrow adipose tissue (MAT) in this review. In the proceeding text, we focus on the developmental origin and physiologic functions of MAT. We also discuss the signals that cause the accumulation and loss of marrow adipocytes and the ability of these cells to regulate other cell lineages in the BM. Last, we consider roles for MAT in human physiology and disease.

https://www.ncbi.nlm.nih.gov/pubmed/31127816

Bone marrow adipocytes.

Horowitz MC, Berry R, Holtrup B, Sebo Z, Nelson T, Fretz JA, Lindskog D, Kaplan JL, Ables GP, Rodeheffer MS, Rosen CJ.

Adipocyte. 2017 Jul 3;6(3):193-204.

PMID: 28872979

Adipocytes were identified in human bone marrow more than a century ago, yet until recently little has been known about their origin, development, function or interactions with other cells in the bone marrow. Little functional significance has been attributed to these cells, a paradigm that still persists today. However, we now know that marrow adipose tissue increases with age and in response to a variety of physiologic induction signals. Bone marrow adipocytes have recently been shown to influence other cell populations within the marrow and can affect whole body metabolism by the secretion of a defined set of adipokines. Recent research shows that marrow adipocytes are distinct from white, brown and beige adipocytes, indicating that the bone marrow is a distinct adipose depot. This review will highlight recent data regarding these areas and the interactions of marrow adipose tissue (MAT) with cells within and outside of the bone marrow.