Fat tissue, often criticized, plays a crucial role in energy storage and hormone production in the body. However, the prevalence of obesity due to modern lifestyles has resulted in a global increase in conditions like type 2 diabetes and cardiovascular disease.
Fat accumulation related to adverse health consequences
Researchers are endeavoring to elucidate the fundamental aspects of adipose tissue organization, particularly the inflammation linked to obesity, with the aim of revealing the nexus between fat accumulation and adverse health consequences.
In the recent study by Lindsey Muir, Ph.D., Cooper Stansbury, and their research team at the University of Michigan, they utilized a novel method that combines single-cell gene expression analysis with spatial transcriptomics to reveal new immune cell types and their interactions in adipose tissue. This cutting-edge technology captures detailed gene expression profiles in specific tissue regions.
This research, titled “A lipid-associated macrophage lineage rewires the spatial landscape of adipose tissue in early obesity,” has been featured in JCI Insight.
Studying fat presents unique challenges compared to tissues with defined layers like the spinal cord or the brain. In those tissues, it’s easier to verify data and identify specific cell types and their gene expression. However, in adipose tissue, which lacks distinct cell layers, the distribution of cell types is more evenly dispersed. In cases of obesity, fat cells (adipocytes) can expand to a point where they cause cell death and inflammation.
Macrophages responsible for cleaning up dead cells
Researchers conducted a study to explore the immune cell composition in adipose tissue during obesity. They fed mice a high-fat diet for 14 weeks, collected fat tissue, and employed single cell and spatial analyses to assess the mRNA profiles.
By using clustering in the single cell data, they categorized cells with similar genetic profiles. In the process, they made an unexpected finding regarding the macrophage population, which is responsible for cleaning up dead cells and debris.
The study initially expected macrophages to have multiple subtypes. However, it surprised the researchers when they found that numerous highly distinct subtypes emerged, with varying dominance levels over time.
