Unique expression pattern of KIBRA in the enteric nervous system of APP/PS1 mice.

KIBRA has been recognized as a memory-related gene, which is abundant in the brain and kidney of mammals. However, the expression pattern of KIBRA in the "second brain"-enteric nervous system (ENS) is still unknown, especially in neurodegenerative disorders. In this study, we aimed to investigate the detailed expression pattern of KIBRA in the intestinal myenteric nerve plexus of APP/PS1 and wild type mice by whole mount staining technology. The deposition of Aβ and increased levels of phosphorylated Tau (p-Tau) and total Tau (T-Tau) protein were observed in the intestinal myenteric nerve plexus of APP/PS1 mice. Interestingly, the amount of Tuj+ cells remained unchanged between these two groups. Compared to the control mice, the protein levels of KIBRA significantly increased in the jejunal myenteric plexus of APP/PS1 mice, and the proportion of KIBRA+ GABAergic neurons in both the jejunal myenteric nerve plexus and the cortex was much higher in the APP/PS1 mice. But there was no significant difference in the number of KIBRA+ cholinergic neurons and KIBRA+ nitrergic neurons between APP/PS1 and wild type mice. In summary, our study further confirmed that typical pathology features of Alzheimer's disease (AD) not only existed in the central nervous system but also in the ENS.