Nrip2, also known as Nuclear Receptor-Interacting Protein 2, is involved in modulating key biological pathways. It has been shown to interact with components of the Wnt pathway, which is crucial for cell fate determination, proliferation, and self-renewal in various tissues. Dysregulation of the Wnt pathway is associated with numerous diseases, highlighting the importance of Nrip2 in maintaining normal cellular function [1].

In colorectal cancer initiating cells (CCICs), NRIP2 is significantly up-regulated. Overexpression of NRIP2 increases Wnt activity, while its silencing attenuates it. It acts by targeting the transcription factor RORβ, preventing its binding to the downstream HBP1 promoter regions, reducing HBP1 transcription, and ultimately attenuating HBP1-dependent inhibition of TCF4-mediated transcription. This reveals a new mechanism for CCIC self-renewal via the Wnt activity [1].

In podocyte injury, NRIP2 binds β-catenin and stabilizes it through the ubiquitin-proteasomal pathway. Knockout of Nrip2 in an adriamycin-induced nephropathy mouse model ameliorates podocyte injury, glomerulosclerosis, and proteinuria by inhibiting β-catenin activation. Also, NRIP2 is upregulated in podocytes of patients with focal segmental glomerulosclerosis (FSGS) [2].

In conclusion, Nrip2 plays essential roles in modulating the Wnt pathway and β-catenin stabilization, which are relevant to diseases such as colorectal cancer and podocyte-related kidney diseases. Gene knockout models, like the Nrip2 knockout mice, have been instrumental in revealing these functions, providing insights into the underlying disease mechanisms and potential therapeutic targets.

References:

1. Wen, Zhenzhen, Pan, Tianhui, Yang, Saisai, Mao, Jianshan, Zhu, Yongliang. 2017. Up-regulated NRIP2 in colorectal cancer initiating cells modulates the Wnt pathway by targeting RORβ. In Molecular cancer, 16, 20. doi:10.1186/s12943-017-0590-2. https://pubmed.ncbi.nlm.nih.gov/28137278/

2. Hou, Qing, Le, Weibo, Kan, Shuyan, Liu, Zhihong, Chen, Zhaohong. 2021. Nuclear Receptor Interacting Protein-2 Mediates the Stabilization and Activation of β-Catenin During Podocyte Injury. In Frontiers in cell and developmental biology, 9, 781792. doi:10.3389/fcell.2021.781792. https://pubmed.ncbi.nlm.nih.gov/35004680/