Fabp6, also known as ileal lipid binding protein, is a bile acid carrier protein. It is a component of the bile acid recovery system in the small intestine, playing a crucial role in maintaining bile acid homeostasis. It may also be involved in fatty acid metabolism [4,5].

In gene-knockout (KO) mouse models, Fabp6 -/- mice showed enhanced excretion of both bile acids and fat on a Western-style diet (WSD), indicating a role in dietary fat absorption [4]. In addition, male Fabp6 -/- mice had greater adiposity despite increased fat excretion, along with sex-specific changes in gut microbiota composition. The ovulation rate in response to superovulatory treatment was markedly decreased in Fabp6-deficient mice, suggesting its importance in ovarian function and fertility [6]. In cancer research, knockdown of FABP6 in colorectal cancer cells increased major histocompatibility complex (MHC) class 1 expression and promoted immune-related chemokine secretion, enhancing tumor cell immunogenicity [1]. In esophageal tumors, FABP6 was highly expressed in a cluster of epithelial cells, suggesting a role in tumor growth [2]. In glioblastoma cells, inhibition of FABP6 reduced tumor cell invasion and angiogenesis [3].

In summary, Fabp6 is essential for bile acid and fat metabolism, ovarian function, and may have implications in various diseases, especially cancers. KO mouse models have been instrumental in revealing its role in these biological processes and disease conditions, providing insights into potential therapeutic targets for treating related diseases.

References:

1. Lian, Wenping, Wang, Zhongquan, Ma, Yajie, Ding, Xianfei, Peng, Mengle. 2022. FABP6 Expression Correlates with Immune Infiltration and Immunogenicity in Colorectal Cancer Cells. In Journal of immunology research, 2022, 3129765. doi:10.1155/2022/3129765. https://pubmed.ncbi.nlm.nih.gov/36033394/

2. Zhang, Dengfeng, Zhao, Fangchao, Liu, Haitao, Li, Zhirong, Li, Shujun. 2024. FABP6 serves as a new therapeutic target in esophageal tumor. In Aging, 16, 1640-1662. doi:10.18632/aging.205448. https://pubmed.ncbi.nlm.nih.gov/38277205/

3. Pai, Feng-Cheng, Huang, Hsiang-Wei, Tsai, Yu-Ling, Chang, Hsin-Han, Chen, Ying. 2021. Inhibition of FABP6 Reduces Tumor Cell Invasion and Angiogenesis through the Decrease in MMP-2 and VEGF in Human Glioblastoma Cells. In Cells, 10, . doi:10.3390/cells10102782. https://pubmed.ncbi.nlm.nih.gov/34685761/

4. Habib, Salam M, Zwicker, Brittnee L, Wykes, Linda, Agellon, Luis B. . Sexually dimorphic response of mice to the Western-style diet caused by deficiency of fatty acid binding protein 6 (Fabp6). In Physiological reports, 9, e14733. doi:10.14814/phy2.14733. https://pubmed.ncbi.nlm.nih.gov/33527741/

5. Bonné, Anita, Gösele, Claudia, den Bieman, Maria, van Lith, Hein, van Zutphen, Bert. . Sequencing and chromosomal localization of Fabp6 and an intronless Fabp6 segment in the rat. In Molecular biology reports, 30, 173-6. doi:. https://pubmed.ncbi.nlm.nih.gov/12974472/

6. Duggavathi, Raj, Siddappa, Dayananda, Schuermann, Yasmin, Praslickova, Dana, Agellon, Luis B. 2015. The fatty acid binding protein 6 gene (Fabp6) is expressed in murine granulosa cells and is involved in ovulatory response to superstimulation. In The Journal of reproduction and development, 61, 237-40. doi:10.1262/jrd.2014-139. https://pubmed.ncbi.nlm.nih.gov/25754072/