High lipid levels in people with type 2 diabetes and obesity are more harmful than previously thought, according to findings from a new study which found that stressed cells can damage nearby cells.
In patients with metabolic diseases, elevated lipid levels in the blood create stress in muscle cells – a reaction to changes outside the cell which damage their structure and function.
The study, published in Nature Communications, shows that these stressed-out cells give off a signal which can be passed on to other cells.
The signals, known as ceramides, may confer a short-term protective benefit, because they are part of a mechanism designed to reduce stress in the cell. But in long term conditions such as metabolic diseases, the signals can actually kill the cells and worsen symptoms and the illness.
High lipid levels have long been known to damage tissues and organs, contributing to the development of cardiovascular and metabolic diseases including type 2 diabetes, a condition which can be caused by obesity.
Professor Lee Roberts, who supervised the research, said: “Although this research is at an early stage, our discovery may form the basis of new therapies or therapeutic approaches to prevent the development of cardiovascular and metabolic diseases such as diabetes in people with elevated blood fats in obesity.”
In the lab, the team replicated the blood lipid levels observed in humans with metabolic disease by exposing skeletal muscle cells to palmitate, a fatty acid. The cells began to transmit the ceramide signal.
When these cells were mixed with others which had not been previously exposed to lipids, the researchers found that they communicated with each other, transporting the signal in packages called extracellular vesicles.
The experiment was reproduced in human volunteers with metabolic diseases and gave comparable results. The findings provide a completely new angle on how cells respond to stress, with important consequences for our understanding of certain metabolic diseases including obesity.
Professor Roberts said: “This research gives us a novel perspective on how stress develops in the cells of individuals with obesity, and provides new pathways to consider when looking to develop new treatments for metabolic diseases.
“With obesity an ever-increasing epidemic, the burden of associated chronic disease such as type 2 diabetes necessitates new treatments. We hope the results of our research here open a new avenue for research to help address this growing concern.”
Source: University of Leeds
