Yuichi Oike of Kumamoto University in Japan states that a protein that causes ongoing, low-grade inflammation within fat tissues, also contributes to the health consequences that come with obesity.
The culprit Oike’s team identifies is a fat-derived protein called angiopoietin-like protein 2, or Angptl2. In mice, Angptl2 levels are elevated in fat tissue. Those levels increase even more in the oxygen-deprived conditions typically found within obese fat tissue.
Higher Angptl2 levels are also found in the blood of people with higher body mass index and insulin levels.
Obese mice lacking Angptl2 show less inflammation in their fat tissue and are less insulin resistant, the researchers report. Likewise, otherwise healthy mice made to have higher than normal Angptl2 levels in their fat tissue develop inflammation and insulin resistance.
Angptl2 starts an inflammatory cascade, causing blood vessels to remodel and attracting immune cells called macrophages, they note.
The researchers concluded that Angptl2 is a new molecular target that could be used to improve the diagnosis and treatment of obesity and related metabolic diseases.
Cell Press, news release, Sept. 1, 2009