TWrapping the baby in soft, squishy fat rolls plays an important role. they are important warehouses brown fat cellsFat cells burn energy and release heat, helping to keep your baby warm.1 As babies grow, they lose most of these brown fat stores. Adults have a higher proportion of white adipose tissue (WAT), which stores fat as the body’s energy store. However, some cells embedded within WAT can burn fat. These cells that exhibit brown fat-like properties are called beige fat cells.
Now, researchers have discovered that inhibiting a protein within subcutaneous WAT confers fat-burning properties. beige fat cells.2 The result is clinical research journalrevealed that mature adipocytes exhibit plasticity and identified pathways that may be useful in developing treatments for obesity and metabolic diseases.
Inducing fat burning by converting other cell types into energy-consuming cells is not a new concept. Researchers previously coaxed stem cells to burn energy beige fat cells For therapeutic purposes.3 “However, the stumbling block in this field is that [adult] Stem cells are rare.” Brian Feldman He is a pediatric endocrinologist at the University of California, San Francisco and a co-author of the study. In contrast, white adipocytes are more readily available.
Feldman and his team previously discovered that transcription factors Kruppel-like factor 15 (KLF15) It affects adipogenesis, the process by which stem cells produce fat cells.4 To determine whether KLF15 is involved in adipocyte maintenance, Feldman’s team measured KLF15 expression in fat isolated from different parts of the mouse body. They have higher levels of WAT. Klf15 Comparison with brown adipose tissue (BAT). Deleting Klf15 Expression of genes related to the identity and function of brown fat was induced in white adipocytes isolated from mice. With these findings, researchers Klf15 This level may be required for BAT to generate heat.
Exposure to cold activates BAT, resulting in the production of heat. beta-adrenergic signaling aisle.5 When a researcher deletes Klf15 Increased expression of genes encoding β-1 adrenergic receptors was observed in mouse white adipocytes. Under treatment Klf15Adipocytes deleted with β-adrenergic stimulants had enhanced expression of brown fat-related genes.
Next, the researchers used deficient mice. Klf15 In particular, we will look at adipocytes to determine the effects of gene deletion in vivo. The researchers observed that the mice lacked subcutaneous WAT. Klf15 Compared to tissues from mice in which the protein was expressed, it appeared browner and had higher expression levels of brown fat-related genes. Klf15. The researchers observed increased expression of the beta-1 adrenergic receptor gene and protein in these mice, consistent with their in vitro findings.
When researchers monitored metabolic rates, Klf15 In the knockout mice, they observed that these mice expended more energy compared to controls.
“Rather than targeting stem cells, by targeting mature fat, [therapeutic] It’s Main Street,” Feldman said.
To see if these results applied to human fat cells, the researchers performed a knockdown. KLF15 Human adipocytes obtained from subcutaneous WAT biopsy. Consistent with the results of animal experiments, KLF15 Knockdown increased the expression of brown adipocyte-related genes. The researchers used an assay to estimate the metabolic rate of these human adipocytes and found that: KLF15 Knockdown causes an increase in oxygen consumption rate, indicating enhanced energy metabolism, a characteristic of BAT.
These results pinpoint its role in fat burning pathways in humans, Feldman said. “We think some of the previous research has not translated well into therapeutics because it targeted specific proteins that are not the ones we think are most relevant to humans,” he said. added.
“This is very important work,” he said. Shingo KajimuraHe is a molecular biologist at Harvard University but was not involved in the study. But he believes that a combination of approaches that control both food intake and energy expenditure could yield a more effective anti-obesity drug than simply activating energy-burning brown fat.
“Consuming brown fat is beneficial when you think about metabolic health, and it goes beyond just regulating weight,” he said. “In that sense, it is extremely important to fundamentally understand how brown and beige fats are regulated. This paper makes a significant contribution to our fundamental understanding of biology.”
