Expression of perilipins in human skeletal muscle in vitro and in vivo in relation to diet, exercise and energy balance

Abstract

The perilipin proteins enclose intracellular lipid droplets. We describe the mRNA expression of the five perilipins in human skeletal muscle in relation to fatty acid supply, exercise and energy balance. We observed that all perilipins were expressed in skeletal muscle biopsies with the highest mRNA levels of perilipin 2, 4 and 5. Cultured myotubes predominantly expressed perilipin 2 and 3. In vitro, incubation of myotubes with fatty acids enhanced mRNA expression of perilipin 1, 2 and 4. In vivo, low fat diet increased mRNA levels of perilipin 3 and 4. Endurance training, but not strength training, enhanced the expression of perilipin 2 and 3. Perilipin 1 mRNA correlated positively with body fat mass, whereas none of the perilipins were associated with insulin sensitivity. In conclusion, all perilipins mRNAs were expressed in human skeletal muscle. Diet as well as endurance exercise modulated the expression of perilipins.

Keywords::

• PAT-proteins
• dietary fat
• strength training
• endurance training

Acknowledgements

We thank Dr. Andreas Wensaas Hvammen, University of Oslo, Norway, for providing data on fatty acid incubation of myotubes; MSc Henrik Lian, University of Oslo, for providing data from the myotube differentiation study; bioengineer Anne Randi Enget, University of Oslo, for running RT-PCR on the aerobic interval training study; MSc Ellef Fange Gjelstad, Norway, for programming support in R; and Dr. Gerbrand Koster and Professor Oddmund Bakke of the NORMIC-UiO imaging platform, University of Oslo, for support and use of equipment.

Declaration of interest

This work was supported by LIPGENE − an EU 6th Framework Program Integrated Project (FOOD-CT-2003-505944); the Norwegian Foundation for Health and Rehabilitation; South-Eastern Norway Regional Health Authority; Johan Throne Holst Foundation for Nutrition Research, and Freia Medisinske Fond. The authors report no declarations of interest.