Direct conversion of human myoblasts into brown-like adipocytes by engineered super-active PPARγ

Area of Science:

• Cell Biology
• Metabolism
• Adipocyte Differentiation

Background:

• Brown adipose tissue (BAT) plays a crucial role in thermogenesis and energy expenditure.
• Understanding the mechanisms of brown adipocyte differentiation is vital for metabolic research.
• Developing new models for studying brown fat is essential for therapeutic advancements.

Purpose of the Study:

• To investigate if enhanced peroxisome proliferator-activated receptor gamma (PPARγ) signaling can reprogram human myoblasts into brown-like adipocytes.
• To establish a novel cell model for research into brown adipose tissue (BAT) browning.

Main Methods:

• Human myoblasts were transduced with lentiviral vectors expressing either PPARγ or a super-activated form, M3-PPARγ.
• M3-PPARγ incorporates the transactivation domain of MyoD to enhance PPARγ signaling.
• Reprogrammed adipocytes were analyzed for brown adipocyte markers (UCP1, CIDEA, PRDM16) using qPCR and protein analysis, with comparisons to white adipocytes and native brown fat.

Main Results:

• M3-PPARγ demonstrated stronger constitutive activity than PPARγ in reporter assays.
• Both PPARγ and M3-PPARγ induced adipogenesis in myoblasts.
• M3-PPARγ significantly upregulated brown adipocyte markers: UCP1 (1,050-fold), CIDEA (2.4-fold), and PRDM16 (5.0-fold), and increased mitochondrial content (4-fold) compared to PPARγ.

Conclusions:

• Super-activation of PPARγ effectively converts human myoblasts into brown-like adipocytes.
• This study presents a new and effective approach for deriving brown-like adipocytes in vitro.
• The established cell model offers a valuable tool for future browning research.