IRX3 promotes adipose tissue browning and inhibits fibrosis in obesity-resistant mice

• Published in: The international journal of biochemistry & cell biology 2024-10, Vol.175, p.106638, Article 106638
• Main Authors: Yan, Xi-yue, Luo, Yuan-yuan, Chen, Hui-jian, Hu, Xiao-qin, Zheng, Peng, Fang, Hong-ting, Ding, Fei, Zhang, Li, Li, Zhen, Yan, You-e
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; Adipose Tissue, Brown - metabolism; Adipose Tissue, Brown - pathology; Adipose Tissue, White - metabolism; Adipose Tissue, White - pathology; Animals; Browning; Diet, High-Fat - adverse effects; Fibrosis; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; IRX3; Male; Mice; Mice, Inbred C57BL; Obesity - genetics; Obesity - metabolism; Obesity - pathology; Obesity resistance; Thermogenesis - genetics; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 1357-2725; 1878-5875; 1878-5875
• DOI: 10.1016/j.biocel.2024.106638

Obesity is one of the threats to human health and survival. High fat diet (HFD)-induced obesity leads to adipose tissue fibrosis and a series of metabolic diseases. There are some people still thin under HFD, a phenomenon known as the "obesity resistance (OR) phenotype". It was found that Iroquois homeobox 3 (IRX3) is considered as a regulator in obesity, but the regulatory mechanism between OR and IRX3 is still unclear. In this study, we investigated OR on a HFD and the role of the IRX3 gene. Using mice, we observed that OR mice had lower body weights, reduced liver lipid synthesis, and increased white adipose tissue (WAT) lipolysis compared to obesity-prone (OP) mice. Additionally, OR mice exhibited spontaneous WAT browning and less fibrosis, correlating with higher Irx3 expression. Utilizing 3T3-L1 differentiated adipocytes, our study demonstrated that overexpression of Irx3 promoted thermogenesis-related gene expression and reduced adipocyte fibrosis. Therefore, Irx3 promotes WAT browning and inhibits fibrosis in OR mice. These results provide insight into the differences between obesity and OR, new perspectives on obesity treatment, and guidance for lessening adipose tissue fibrosis. [Display omitted] •IRX3 protects the mice from obesity and metabolic disorders.•IRX3 plays a key role in white adipose tissue browning of obesity-resistant mice.•IRX3 protects adipose tissue from fibrosis in obesity-resistant mice.