Scientists are nearer to understanding what happens in the fat cells of obese people.
Life inside a fat cell may be as complex as the universe itself.
That’s the conclusion of a group of Sydney scientists who surveyed for the first time the contents of the cells most of us would rather live without.
Scientists can now use this map to understand what goes awry in the cells of people with diseases like diabetes and obesity.
New technology: Sean Humphrey.
The team, led by researchers from the Garvan Institute of Medical Research, found individual fat cells contained multiple copies of between 10 000 and 12 000 proteins, each of which could be modified into up to 20 different versions of themselves. Proteins perform the work of every cell in the body.
The fat cells, collected from mice, were treated with insulin, a hormone released by the pancreas after eating which instructs muscle, liver and fat cells to absorb glucose from the blood.
They found 15 per cent of the cell’s proteins responded to the hormone’s signals, which no longer functioned properly in people with diabetes.
‘‘Until this study we did not really appreciate the scale of insulin regulation, which represents something as complex as the universe itself in every cell of our body,’’ said the research leader, David James, from the Garvan.
The findings re-enforce the elaborate biological processes that underpin diseases such diabetes and the difficulties scientists face treating them.
Sean Humphrey, who conducted the research as part of his PhD, said the complexity of fat cells came from the large number of proteins they contained, but also the vast number of ways these molecules could transform themselves to alter their function, a process known as phosphorylation.
‘‘The cell has the means of communicating many different things using these mechanisms,’’ said Mr Humphrey
The study, published in the journal Cell Metabolism, was made possible using the latest mass spectrometers, sophisticated machines that can identify thousands of molecules by their mass and capture a complete picture of cells at work.
‘‘This technology and methods are opening up a window into the cell to see how it communicates inside [itself] and with the rest of the body like never before,’’ said Mr Humphrey.
The new approach may also lead to drug discoveries that take into account the environment of the entire cell.
Until now scientists knew of only a dozen or so proteins that responded to insulin inside fat cells.
‘‘Unless we look at the whole picture, we are never going to figure these problem out,’’ said Professor James, who has focused his research on trying to understand why cells become resistant to insulin in diseases like diabetes.
The team will now survey human fat cells from healthy people and those with diabetes.