Our bodies have a complex system of adipose tissue that does more than store excess energy. When functioning properly, adipose tissue helps maintain normal blood sugar levels and overall metabolic health. However, in obesity, this essential system may not function properly when fat cells become too large. Now UCLA scientists have discovered why.
Posted in cell report | Estimated reading time: 6 minutes
A team led by Claudio Villanueva, PhD, of UCLA’s Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research has identified an important molecular mechanism that explains why obesity causes fat cells to divide, enlarging them instead of producing new, smaller cells. The answer lies in the inability of adipose stem cells to produce essential cellular components called ribosomal factors.
“Adipose tissue gets a bad rap, but it’s actually essential for maintaining normal glucose metabolism,” explains Dr. Villanueva. “What happens in obesity is you have too much fatty tissue and it doesn’t function optimally.”
When fat cells become too large, they cannot properly store energy from food. This excess energy can be redirected to other parts of the body, potentially leading to fatty liver disease and cardiovascular problems. It’s like trying to fit more clothes into an already full closet. Eventually things start to spill out and cause problems elsewhere.
The research team found that fat cells in obese mice were four to five times larger than fat cells in lean mice. These enlarged cells occur when fat stem cells lack the appropriate ribosomal factors, which prevents them from dividing and producing new, healthy fat cells.
But there is hope. Scientists found that when obese mice were given a drug called rosiglitazone, the fat stem cells began producing normal levels of ribosomal factors again. This triggered the creation of new, smaller fat cells that could properly store and process energy.
Most interestingly, although the mice remained obese after treatment, their type 2 diabetes symptoms essentially disappeared. “It’s like replacing one full storage device with several smaller storage devices. The system works better,” says Villanueva.
The findings are especially important for communities disproportionately affected by obesity and diabetes. “I am originally from Nicaragua,” says Villanueva. “Latinos have a higher risk of developing obesity and type 2 diabetes, so we hope this study can have a positive impact on our community.”
This research opens new avenues for developing treatments that may help improve fat tissue function in obese people. By understanding exactly how fat cells grow and divide, scientists can develop treatments that encourage the creation of healthy new fat cells rather than allowing existing fat cells to grow dangerously large.
Key Terms
- ribosomal factor
- It helps cells create new proteins and is an essential cellular component needed for proper cell division and function.
- fat stem cells
- Special cells in fat tissue that can divide and develop into new fat cells when needed.
- glucose metabolism
- The process by which your body processes sugar (glucose) for energy and maintain healthy blood sugar levels.
Test your knowledge
Why is enlarging fat cells a problem?
Because enlarged fat cells cannot store energy properly, excess energy can be redirected to other organs, such as the liver or heart, potentially causing disease.
What role do ribosomal factors play in adipose tissue health?
Ribosomal factor is essential for fat stem cells to divide and create new, healthy fat cells. Without this, existing fat cells will grow larger instead of dividing.
What effect did the treatment have on the obese mice?
The mice remained obese, but their type 2 diabetes symptoms essentially disappeared because their fat tissue became smaller and began to function properly alongside healthy fat cells.
Why is this research particularly important for certain communities?
This research is particularly relevant for the development of targeted treatments because some communities, such as Latinos, have a higher risk of developing obesity and type 2 diabetes.
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