Salsalate activates brown adipose tissue in mice

Area of Science:

• Metabolic research
• Obesity studies
• Pharmacology

Background:

• Type 2 diabetes is often associated with glucose intolerance and dyslipidemia.
• Salsalate is known to improve these conditions, but its underlying molecular mechanisms remain unclear.
• High-fat diets induce obesity, glucose intolerance, and dyslipidemia in experimental models.

Purpose of the Study:

• To investigate the molecular mechanisms by which salsalate exerts its beneficial metabolic effects.
• To determine if salsalate impacts obesity and related metabolic dysfunctions induced by a high-fat diet.
• To explore the role of brown adipose tissue (BAT) activation in salsalate's action.

Main Methods:

• Mice were fed a high-fat diet and treated with salsalate during and after obesity development.
• Assessment of body weight, fat mass, glucose tolerance, and plasma triglyceride levels.
• Evaluation of fatty acid uptake in brown adipose tissue (BAT) and its effect on adipocyte respiration and gene expression (Ucp1).
• In vitro studies using differentiated T37i brown adipocytes treated with salsalate and inhibitors of cAMP-dependent protein kinase (PKA).

Main Results:

• Salsalate treatment attenuated and reversed high-fat diet-induced weight and fat mass gain.
• Improved glucose tolerance and reduced plasma triglyceride levels were observed in salsalate-treated mice.
• Salsalate promoted fatty acid uptake by BAT, decreased intracellular lipid content, and increased rectal temperature, indicating enhanced BAT activity.
• In vitro, salsalate increased uncoupled respiration and upregulated Ucp1 expression in brown adipocytes, effects mediated by the PKA pathway.

Conclusions:

• Salsalate activates brown adipose tissue (BAT), likely through direct activation of brown adipocytes via the PKA pathway.
• This BAT activation represents a novel mechanism contributing to salsalate's beneficial effects on glucose intolerance and dyslipidemia.
• The findings suggest a potential therapeutic strategy for type 2 diabetes and obesity by targeting BAT activation with salsalate.