Analysis of Main Proteins Associated with Lipid Droplets from Peri- Adrenal Adipose Tissue of Patients with Cushing’s Syndrome

ABSTRACT

The Cushing’s syndrome results from chronic exposure to excess glucocorticoids produced by the adrenal cortex. The most common feature of patients with Cushing’s syndrome is central obesity associated with dyslipidaemia and insulin resistance leading to type 2 diabetes and cardiovascular diseases. In the adipocytes, triacylglycerol and cholesterol esters are stored within an intracellular lipid droplet covered by a monolayer of phospholipids and surrounded by proteins involved in the regulation of lipolysis. Since the protein composition of adipocyte lipid droplets from patients with Cushing’s syndrome has not yet been reported, we used two-dimensional gel electrophoresis followed by mass spectrometry to identify the main lipid droplet-associated proteins from peri-adrenal adipose cell of patients with this syndrome.

The lipid droplet proteome of peri-adrenal adipose cell of patients with Cushing’s syndrome is highly complex and contains more than 500 proteins. MALDI-TOF MS analysis of silver-stained protein spots revealed the identity of 27 proteins clustered into 7 groups according to their known function. Interestingly, proteins involved in response to oxidative stress and endoplasmic reticulum stress were found on the lipid droplets of adipose cell from patients with Cushing’s syndrome.

Keywords:

Adipocyte, Cushing’s syndrome, endoplasmic reticulum, lipid droplet, two-dimensional gel electrophoresis..