We know very well that high levels of fat in the blood, such as cholesterol or triglycerides, are not good for health, and can affect the proper functioning of the heart, among other things. Now, a study published in Nature Communications adds fuel to the fire and shows more dangers that we didn’t know about.
One of the situations that occur in our body when fats are above what is recommended is that they cause additional stress on muscle cells , causing damage to their structure and function. What this research has discovered is that these stressed cells also emit a signal that can be transmitted to other cells and cause further damage.
These signals take the form of molecules called ceramides , which are a family of lipids found in cell membranes. Although their normal function is to reduce cellular stress, in long-term metabolic diseases, such as type 2 diabetes, they can, on the contrary, destroy cells and aggravate the symptoms of the pathology.
“Although this research is at an early stage, our discovery could form the basis for new therapies or therapeutic approaches to prevent the development of cardiovascular and metabolic diseases, such as diabetes, in people with high blood fats in obesity,” says Dr. molecular physiologist Lee Roberts, from the University of Leeds, in the United Kingdom.
Using muscle cells from humans that were engineered to mimic cells from people with metabolic diseases, the researchers were able to activate ceramide signaling with the addition of a fatty acid known as palmitate.
What the scientists saw is that when these cells mixed with others that had not been exposed to fats, they began to communicate with each other, transferring ceramides into packages called extracellular vesicles , which are naturally released from all cells. The same processes that were observed in human cells occurred in tests with mice.
Although more research is needed to understand what this exchange of ceramides means, it is known that these molecules can be problematic . The increase in fat in the blood seems to cause the cells to share the stress with their neighbors.
Based on what was observed in the research, scientists believe that this communication system between cells could be one of the reasons why people who suffer from obesity end up developing more complications, such as diabetes. The researchers also acknowledge that there could be more factors, as yet unknown, that affect this situation.
The discovery of this transmission system between cells could be useful to find a way to avoid the complications associated with high levels of fat in the blood. The idea would be to somehow block the ceramides. However, this is still a long way off.
As the researchers point out, obesity rates have tripled since 1975, and the number of obese adults, who have higher levels of fat in their blood, is now 650 million people, according to the latest data from the World Organization of Health (WHO).
“As obesity is a growing epidemic, the associated chronic disease burden, such as type 2 diabetes, requires new treatments,” says Roberts. “We hope that the results of our investigation will open up a new avenue of investigation to help address this growing concern.”
Mcnally et al. 2022. Long-chain ceramides are cell non-autonomous signals linking lipotoxicity to endoplasmic reticulum stress in skeletal muscle. Nature Communications. DOI: https://doi.org/10.1038/s41467-022-29363-9