1.A.8.10.15
The Aquaporin-8 (Aqp8) transporter is permeable to water, NH₃, formamide and H₂O₂, and it is present in the inner membrane of mitochondria and the plasma membrane (Bienert et al., 2007; Saparov et al., 2007; Soria et al., 2010). Cholesterol, via sterol regulatory element-binding protein (SREBP) transcription factors, activates or represses genes involved in its hepatic biosynthetic pathway, and also modulates the expression of hepatocyte mitochondrial aquaporin-8 (mtAQP8), a channel that can function as peroxiporin by facilitating the transmembrane diffusion of H₂O₂. The peroxiporin, mtAQP8, plays a role in the SREBP-controlled hepatocyte cholesterogenesis (Danielli et al. 2019). Aquaporin-8 is important for cytokine-mediated toxicity in rat insulin-producing cells (Krüger et al. 2021). Aquaporin-8 ameliorates hepatic steatosis through the farnesoid X receptor in obese mice (Xiang et al. 2023). Aqp8 is a peroxyporin, transporting P₂O₂, which regulates oxidative stress responses (da Silva et al. 2024).