Itln1, also known as intelectin-1 or omentin, is a carbohydrate-binding protein with multiple functions. It is secreted by intestinal epithelial cells and is involved in innate immunity, as it binds microbial glycans [2,4]. Itln1 may also play roles in various signaling pathways, such as the PI3K/AKT pathway [6]. Its biological importance extends to multiple physiological and pathological processes, including host-microbiota interaction, disease susceptibility, and tumor-related processes [1,2,3,5,6]. Genetic models, like the knockout mouse model, are valuable for studying its functions in vivo [4].

In a Itln1 knockout mouse model, mice showed increased susceptibility in an acute model of experimentally induced colitis with 2% w/v dextran sulfate sodium (DSS), suggesting that Itln1 plays a role in the pathophysiology of chemically induced colitis. However, in a diet-induced obesity model, no increased susceptibility was observed in terms of weight gain, food intake, or plasma markers of obesity compared to wild-type littermates [4]. In colorectal carcinoma, ITLN1 was frequently lost in tissues and overexpression of ITLN1 inhibited tumor neovascularization and myeloid-derived suppressor cells accumulation, indicating its tumor-suppressive role [3].

In conclusion, Itln1 is crucial in innate immunity and host-microbiota interactions. Its knockout mouse model has revealed its role in chemically induced colitis, while studies in cancer models, especially colorectal carcinoma, have shown its potential as a tumor-suppressor gene. These findings contribute to our understanding of diseases related to inflammation and cancer, providing insights for potential therapeutic strategies.

References:

1. Matute, Juan D, Duan, Jinzhi, Flak, Magdalena B, Turner, Jerrold R, Blumberg, Richard S. 2022. Intelectin-1 binds and alters the localization of the mucus barrier-modifying bacterium Akkermansia muciniphila. In The Journal of experimental medicine, 220, . doi:10.1084/jem.20211938. https://pubmed.ncbi.nlm.nih.gov/36413219/

2. Nonnecke, Eric B, Castillo, Patricia A, Dugan, Amanda E, Lönnerdal, Bo, Bevins, Charles L. 2021. Human intelectin-1 (ITLN1) genetic variation and intestinal expression. In Scientific reports, 11, 12889. doi:10.1038/s41598-021-92198-9. https://pubmed.ncbi.nlm.nih.gov/34145348/

3. Chen, Li, Jin, Xiao-Han, Luo, Jie, Wang, Feng-Wei, Xie, Dan. 2021. ITLN1 inhibits tumor neovascularization and myeloid derived suppressor cells accumulation in colorectal carcinoma. In Oncogene, 40, 5925-5937. doi:10.1038/s41388-021-01965-5. https://pubmed.ncbi.nlm.nih.gov/34363021/

4. Nonnecke, Eric B, Castillo, Patricia A, Akahoshi, Douglas T, Bevins, Charles L, Lönnerdal, Bo. 2022. Characterization of an intelectin-1 (Itln1) knockout mouse model. In Frontiers in immunology, 13, 894649. doi:10.3389/fimmu.2022.894649. https://pubmed.ncbi.nlm.nih.gov/36072603/

5. Au-Yeung, Chi-Lam, Yeung, Tsz-Lun, Achreja, Abhinav, Nagrath, Deepak, Mok, Samuel C. 2020. ITLN1 modulates invasive potential and metabolic reprogramming of ovarian cancer cells in omental microenvironment. In Nature communications, 11, 3546. doi:10.1038/s41467-020-17383-2. https://pubmed.ncbi.nlm.nih.gov/32669559/

6. Paval, D Robert, Di Virgilio, Thomas George, Skipworth, Richard J E, Gallagher, Iain J. 2022. The Emerging Role of Intelectin-1 in Cancer. In Frontiers in oncology, 12, 767859. doi:10.3389/fonc.2022.767859. https://pubmed.ncbi.nlm.nih.gov/35186726/