A smooth muscle-like origin for beige adipocytes.

Area of Science:

• Metabolism and Endocrinology
• Cell Biology
• Molecular Biology

Background:

• Thermogenic adipocytes, including brown and beige cells, are crucial for energy expenditure and heat production.
• Understanding the distinct molecular signatures and origins of these cell types is vital for metabolic research.

Purpose of the Study:

• To comprehensively characterize the gene expression profiles of brown and beige adipocytes in vivo.
• To investigate the cellular origin of beige adipocytes.

Main Methods:

• Ribosomal profiling (Ribo-seq) was employed to analyze gene expression in brown and beige adipocytes from various fat depots.
• In vivo fate mapping using Myh11-driven Cre systems was utilized.
• Ectopic expression studies of PRDM16 in vascular smooth muscle cells were performed in vitro.

Main Results:

• A detailed molecular profile of brown and beige adipocytes in vivo was generated, highlighting similarities and differences.
• Beige adipocytes exhibit a distinct smooth muscle-like gene expression signature not found in classical brown adipocytes.
• In vivo fate mapping suggests a smooth muscle-like origin for a subset of beige adipocytes.
• Ectopic PRDM16 expression induced Ucp1 expression in vascular smooth muscle cells, converting them to adipocytes.

Conclusions:

• This study provides a comprehensive in vivo molecular portrait of brown and beige adipocytes.
• A novel smooth muscle-like origin for beige adipocytes has been identified.
• These findings offer new insights into adipocyte development and thermogenesis.