Osbpl2, also known as oxysterol-binding protein-related protein 2, is an important regulator in cellular lipid metabolism and transport [1]. It is involved in multiple cellular processes such as maintaining ciliogenesis by regulating the homeostasis of PI(4,5)P2 on the cilia membrane [2], and is associated with pathways like the Sonic Hedgehog (Shh) signaling pathway [2].

In gene-knockout models, Osbpl2-KO mice exhibited progressive hearing loss, abnormal cochlear development with defective cilia, and down-regulation of key molecules in the Shh signaling pathway [2]. Osbpl2-disrupted pigs showed progressive hearing loss, hypercholesterolaemia, and high-fat diet aggravated these phenotypes [1]. In HEI-OC1 cells, knockdown of Osbpl2 augmented cell death and apoptosis induced by H2O2, and inhibited the AKT/FOXG1 signaling pathway [3]. Deletion of Osbpl2 in auditory cells increased cholesterol biosynthesis and ROS production by inhibiting AMPK activity [4].

In conclusion, Osbpl2 is crucial for maintaining normal physiological functions related to lipid metabolism, cilia formation, and cell survival. The gene-knockout mouse and pig models have significantly contributed to understanding its role in diseases such as hearing loss, hypercholesterolaemia, and age-related hearing loss. These findings provide insights into the underlying mechanisms of these diseases and potential therapeutic targets.