Gene Expression Differences in Fat Tissue May Inform Targeted Treatment for Obesity

Rockville, Md. (Dec. 12, 2024)-New research reveals significant differences in gene expression related to metabolism, inflammation and cardioprotection in the fat tissue of lean and obese mice. These findings could advance the development of targeted therapies for different types of adipose tissue, addressing critical health concerns. The study is published in Physiological Genomics and has been chosen as an APSselect article for December.

Adipose Tissue: More Than Fat Storage

Once considered merely a storage site for fats, adipose tissue is now recognized as a vital endocrine organ. Dysfunction in this tissue contributes to metabolic disorders and poses a significant risk for heart disease. Two types of adipose tissue are involved in obesity, but with different associations.

• Visceral adipose tissue (VAT) surrounds the abdominal organs and is linked to chronic inflammation and insulin resistance.
• Subcutaneous adipose tissue (SAT) resides under the skin and is not associated with increased inflammation.

Key Findings

These differences led researchers from the University of Delaware to investigate gene expression in each of these two types of fat tissue. They analyzed genes from two groups of male mice following different diets for over one year. One group ate a high-fat diet and gained weight and adipose tissue mass. The other group was leaner, having stayed on a standard rodent chow diet. The research team found:

• 308 genes were differentially expressed in the SAT of the lean versus obese mice.
• More than 600 genes were expressed differently in the VAT of the two groups.
• Most of the genes that were upregulated (expressed more abundantly) in the SAT-the less dangerous type of fat-were those that support or enhance metabolic activity related to lipid (fat) handling.
• The majority of genes upregulated in the VAT of the obese mice were related to inflammatory signaling pathways.

"These findings more broadly highlight the major impact of obesity on VAT, whereas SAT appears minimally affected and may even respond by upregulating lipid handling, potentially preserving [adipose tissue] function," the researchers explained.

Some genes were upregulated in SAT and downregulated (expressed less) in VAT, including those that have been found to protect against certain types of heart disease and cancer.

While recognizing that this study was done in solely male animals and obesity affects the sexes differently, the findings "may improve our understanding of associated obesogenic variables and relationship to changes in [adipose tissue] gene expression in response to obesity," the researchers wrote.

Read the full article, "A Long-term High-fat Diet Induces Differential Gene Expression Changes in Spatially Distinct Adipose Tissue of Male Mice." It is highlighted as one of this month's "best of the best" as part of the American Physiological Society's APSselect program. Read this month's selected research articles.

NOTE TO JOURNALISTS: To schedule an interview with a member of the research team, please contact APS Media Relations or call 301.634.7314. Find more research highlights in our Newsroom.

Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.