3D microscopy method improves understanding of immune response to obesity

Some adipose tissue (fatty tissue) is more prone to inflammation-related comorbidities than others, but the reasons why are not well understood. Recognizing this, a team of bioengineering researchers at the University of Illinois Urbana Champaign has developed a technique that pairs microscopy and deep learning to better analyze the microenvironments found within adipose tissue associated with obesity. This advance may illuminate why some adipose tissues are more prone to inflammation—leading to diseases like type 2 diabetes, cancer, and cardiovascular disorders—and help direct future drug therapies to treat obesity.

Inflammation in adipose tissue presents itself as round complexes of inflammatory tissue called crownlike structures. Previous studies have shown that body fat that contains these structures is associated with worse outcomes of obesity and related metabolic disorders, according to the research team’s paper describing their work.

Previously, researchers were confined to the use of 2D slices of tissue and traditional microscopy, limiting what researchers could learn about them. To get a better view, the Illinois research team combined 3D light-sheet microscopy, a fat-clearing technique that renders tissue optically transparent, and deep-learning algorithms that help process the large amount of imaging data produced.

In doing so, the researchers found that the crownlike appearances that gives these structures their name are, in reality, more like 3D shells or concentric spheres surrounding an empty core, explains Andrew Smith, a bioengineering professor and one of the paper’s authors. “Using our new technique, we can determine the crownlike structures’ volume, the specific number of cells associated with them, as well as their size, geometry, and distribution,” Smith says.   

This ability led the team to discover that obesity tends to be associated with a prevalence of rare, massive crownlike structures that are not present in the lean state. “These very large crownlike structures are clustered together and located in the center of the tissue,” Smith says. “And there is no way we could have analyzed this before using our new technique.”

Smith said the research may lead to new drug therapies and new ways to evaluate patients’ metabolic health.

Full details of the work appear in the journal Science Advances.

Source: Illinois News Bureau press release – February 17, 2021