Adaptive changes in individual acyl-CoA esters from hamster BAT during cold acclimation.

Area of Science:

• Metabolism
• Adipose Tissue Biology
• Biochemistry

Background:

• Long-chain fatty acyl-CoA esters (LCFACoAE) are critical metabolic intermediates.
• Brown adipose tissue (BAT) plays a key role in thermogenesis and energy expenditure.
• Understanding LCFACoAE dynamics in BAT is essential for elucidating thermogenic mechanisms.

Purpose of the Study:

• To quantify and characterize LCFACoAE profiles in hamster brown adipose tissue (BAT) under thermoneutral and cold-acclimated conditions.
• To investigate the dynamic changes in specific LCFACoAE in response to cold exposure.
• To assess the role of LCFACoAE in the initiation and maintenance of BAT thermogenesis.

Main Methods:

• Extraction of LCFACoAE from freeze-clamped hamster BAT.
• Separation and identification of individual LCFACoAE using high-performance liquid chromatography (HPLC).
• Quantification of LCFACoAE concentrations (nmol/g protein) and comparison between control and cold-acclimated groups.

Main Results:

• Total LCFACoAE concentrations were significantly higher in cold-acclimated hamsters (648 nmol/g protein) compared to controls (235 nmol/g protein).
• Cold acclimation led to a rapid, fourfold increase in C16:0, C18:0, and C18:1 LCFACoAE within hours.
• These three fatty acyl-CoA esters constituted nearly 50% of total LCFACoAE in cold-acclimated hamster BAT.

Conclusions:

• Cold exposure induces significant dynamic changes in BAT LCFACoAE composition.
• Specific saturated and monounsaturated LCFACoAE (C16:0, C18:0, C18:1) are key players in cold-induced thermogenesis.
• These findings support the proposed role of LCFACoAE in initiating and sustaining BAT thermogenic function.