Adipose tissue depot specific differences of PLIN protein content in endurance trained rats

ABSTRACT

Adipose tissue is classified as either white (WAT) or brown (BAT) and differs not only by anatomical location but also in function. WAT is the main source of stored energy and releases fatty acids in times of energy demand, whereas BAT plays a role in regulating non-shivering thermogenesis and oxidizes fatty acids released from the lipid droplet. The PLIN family of proteins has recently emerged as being integral in the regulation of fatty acid storage and release in adipose tissue. Previous work has demonstrated that PLIN protein content varies among adipose tissue depots, however an examination of endurance training-induced depot specific changes in PLIN protein expression has yet to be done. Male Sprague-dawley rats (n = 10) underwent 8-weeks of progressive treadmill training (18–25 m/min for 30–60 min at 10% incline) or remained sedentary as control. Following training, under isoflurane induced anesthesia epidydmal (eWAT), inguinal subcutaneous (iWAT) and intrascapular brown adipose tissue (BAT) was excised, and plasma was collected. Endurance training resulted in an increase in BAT PLIN5 and iWAT PLIN3 content, while there was no difference in PLIN protein content in endurance trained eWAT. Interestingly, endurance training resulted in a robust increase in ATGL and CGI-58 in eWAT alone. Together these results suggest the potential of a depot specific function of PLIN3 and PLIN5 in adipose tissue in response to endurance training.

KEYWORDS:

• adipose tissue
• endurance exercise
• lipolysis
• perilipin

Disclosure of potential conflicts of interest

No potential conflicts of interest were disclosed.

Author contributions

PCT, SVR, and REKM conceived and designed the experiments. PCT and SVR performed the animal training and experiments and harvested tissues. REKM and SVR collected and assembled the biochemical data. PCT, SVR, and REKM analyzed and interpreted the data. PCT, SVR, and REKM drafted the manuscript. All authors revised the article for intellectual content and approved the final version of the manuscript. All persons designated as authors qualify for authorship, and all those who qualify for authorship are listed.

Acknowledgments

We would like to acknowledge Dr. S.J. Peters and Dr. DC. Wright for their support of this research.

Funding

S.J. Peters is funded by a Natural Sciences and Engineering Research Council of Canada (NSERC) grant. DCW is a Tier II Canada Research Chair and is supported by an Operating Grant from the Canadian Institutes of Health. REK is funded by a Postdoctoral Fellowship from the Alzheimer Society. SV Ramos is funded by an Ontario Graduate Student Scholarship.