Our bodies need different types of cells, so generic cells go through a process in which they become highly specialized to perform specific tasks, enabling all the parts of us to function correctly. New work has shown that the precursors that specialize to become fat cells can be rapidly altered by environmental factors, in particular, two molecules that are associated with fatty food intake, and inflammation. It has been suggested that cell development is impacted by outside influences, but the mechanisms behind this effect have not been known. This work has now identified one such mechanism; the study, by scientists at the Novo Nordisk Foundation Center for Basic Metabolic Research at the University of Copenhagen, has been reported in the International Journal of Obesity.
“Our results stress the importance of a healthy diet and lifestyle for our metabolic health in the years to come. To a large extent, a healthy diet and healthy lifestyle can help prevent the reprogramming of our precursor cells. In the long term, we hope our study may be at the origin of new strategies to reverse the abnormal programming of fat precursor cells, making them healthy and functional once again,” said the leader of the study, Romain Barrès.
In this research, the scientists found that precursor fat cells are impacted by both fatty acid palmitate (from the intake of palm oil, dairy products, and meat), as well as the hormone TNF-alpha (an inflammatory hormone that the body releases during illness). TNF-alpha is also found at higher levels in obese people compared to people of healthy weight. These molecules disrupt the development of fat cells, reprogramming them epigenetically. That causes them to be dysfunctional later on life. The researchers found that in type 2 diabetes patients, cells had been reprogrammed in this way.
While our genes remain mostly the same throughout life, small modifications might be made to those genes that change how they are expressed or activated, epigenetic alterations that are tagged onto genes. Scientists are starting to link some of these epigenetic tags to changes in our biology.
The investigators used fat specimens collected from various surgeries. Of the 43 operations, 15 were performed on lean patients, 14 patients were obese, and 14 had type 2 diabetes and were obese. The state of precursor fat cells from the patients was then compared; in the diabetic individuals, reprogramming had occurred in their cells, making them abnormal.
Next, healthy precursor fat cells were exposed to TNF-alpha and palmitate for only 24 hours. That exposure was enough to induce reprogramming, mimicking what was seen in the diabetics.
The scientists want to find out if the reprogramming can be reversed to make the cells healthy again, but they don’t yet know how it could be done.
“We now know that precursors cells can be reprogrammed in a way that function is impaired at the final stage of their development, but so far no one has discovered how to reverse the process. But it is a promising field,” concluded Romain Barrès.