Scientists from Leipzig University identify new mechanisms for chronic inflammation and wound healing issues
In routine clinical practice, it has been noted that obese individuals are more likely to develop chronic inflammatory disorders like psoriasis at an earlier age and with greater severity. Additionally, these issues are more challenging to treat in people who are obese. Therefore, researchers at Leipzig University Hospital were curious to learn why obese people are more likely to develop chronic inflammatory disorders and chronic wounds that do not heal.
Researchers looked at how saturated fatty acids affect wound healing and inflammation incidence in a study that was recently published in the journal Theranostics.
“Our focus was on the danger molecule S100A9. S100A9, together with many saturated fatty acids, causes abnormal activation and differentiation of macrophages and ultimately leads to the fact that inflammatory reactions do not subside or skin injuries are not properly repaired,” explains study leader Dr. Anja Saalbach, scientist and working group leader at the Department of Dermatology, Venerology and Allergology at Leipzig University Hospital. Macrophages are important cells to initially fight infection. Later, they help the inflammation subside and help the tissue be repaired.
In mouse models, the Leipzig-based researchers have shown that blocking the danger molecule S100A9 normalizes the misdirected activation of macrophages in obesity and thus the inflammatory response and wound healing. Another solution involved feeding the animals a diet with reduced levels of saturated fatty acids. After just one week of dieting, the inflammatory reaction had returned to normal – without the animals necessarily having lost weight.
“Based on our data, it seems that changing a patient’s diet would be enough, even if they do not lose weight as a result,” says Dr. Saalbach.
“In a previous study at Leipzig University Hospital, we showed that saturated fatty acids play a very important role. In mouse models, just four weeks of a diet rich in saturated fatty acids, such as palmitic acid and stearic acid, was enough to increase the occurrence of inflammatory skin reactions,” explains study leader Dr. Saalbach, adding: “The data from our research in animal models has led to a clinical study now being conducted at the Department of Dermatology to investigate whether a change in diet would also aid the treatment of psoriasis in humans.” In addition, the danger molecule S100A9 is now an interesting target structure for scientists in order to normalize misdirected inflammatory reactions and wound healing disorders in obesity.
Reference: “Overexpression of S100A9 in obesity impairs macrophage differentiation via TLR4-NFkB-signaling worsening inflammation and wound healing” by Sandra Franz, Anastasia Ertel, Kathrin M Engel, Jan C. Simon and Anja Saalbach, January 2022, Theranostics.