Inside out: Bone marrow adipose tissue as a source of circulating adiponectin

Area of Science:

• Endocrinology
• Metabolic research
• Adipose tissue biology

Background:

• Adiponectin, an adipocyte-derived hormone, confers cardiometabolic benefits.
• Low adiponectin (hypoadiponectinemia) is linked to metabolic and cardiovascular risks.
• Circulating adiponectin decreases in obesity and insulin resistance, often due to impaired white adipose tissue (WAT) production.

Purpose of the Study:

• To investigate the source of hyperadiponectinemia observed during caloric restriction (CR).
• To explore the role of bone marrow adipose tissue (MAT) in regulating adiponectin levels.
• To elucidate the mechanisms and broader implications of MAT-derived adiponectin.

Main Methods:

• Analysis of adiponectin levels in lean states and during caloric restriction.
• Investigation of potential adiponectin production sites, contrasting WAT and MAT.
• Review and synthesis of existing and novel evidence regarding MAT and adiponectin.

Main Results:

• Caloric restriction (CR) is associated with increased circulating adiponectin (hyperadiponectinemia).
• This increase occurs without a corresponding rise in adiponectin production from WAT.
• Our research implicates bone marrow adipose tissue (MAT) as a novel and significant source of adiponectin during CR.

Conclusions:

• Bone marrow adipose tissue (MAT) is identified as a key contributor to CR-associated hyperadiponectinemia.
• The findings challenge the traditional view of WAT as the sole significant source of circulating adiponectin.
• Further research into MAT biology is crucial for understanding metabolic regulation and adiponectin's role beyond CR.