Importance of CaMKII activation in the regulation of adiposomes and ATP concentration in rat skeletal muscle

Abstract

Lipid droplets, also referred to as adiposomes, are intracellular organelles that are found in most cells. They store oil-based reserves of metabolic energy and components of membrane lipids. Adenosine triphosphate (ATP), produced in the mitochondria, is used to supply energy to the cells. Both lipid droplets and ATP play fundamental roles in energy metabolism, as such critical in the pathogenesis of metabolic diseases like diabetes and obesity. Therefore, understanding their regulation can be a key pathway to understanding the aetiology of obesity and diabetes. Predominantly, CaMKII has been linked to the regulation of mitochondrial and glucose transport genes associated with diabetes and obesity. In this study, the role of exercise-induced CaMKII on the regulation of lipid droplets and ATP concentrations in rat skeletal muscle was investigated. Five to six week-old male Wistar rats were used in this study. Transmission Electron Microscopy (TEM) was performed to determine lipid droplet number/size and mitochondria size. ATP concentration was measured using CellTiter-Glo luminescent assay. This study showed that lipid droplet size and number were decreased in exercised rats when compared to the control rats. Furthermore, the results showed an increase in mitochondrial size and the concentration of ATP by exercise due to CaMKII activation. The results indicate that CaMKII activation by exercise could potentially give a new therapeutic approach to the treatment or prevention of metabolic diseases such as diabetes and obesity.

Keywords:

• exercise
• CaMKII
• lipid droplet
• mitochondria
• rats

Additional information

Funding

This work was funded by the National Research Foundation of South Africa (NRF) through the funding granted to Professor Emmanuel Mukwevho (grant numbers: 76194 and 88062).