Roles of C/EBPβ/AEP in Neurodegenerative Diseases

In recent years, an increasing number of studies have shown that increased activation of aspartic endopeptidases (AEPs) is a common symptom in neurodegenerative diseases (NDDs). AEP cleaves amyloid precursor protein (APP), tau (microtubule-associated protein tau), α- synuclein (α-syn), SET (a 39-KDa phosphoprotein widely expressed in various tissues and localizes predominantly in the nucleus), and TAR DNA-binding protein 43 (TDP-43), and promotes their aggregation, contributing to Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD) pathogenesis. Abundant evidence supports the notion that CCAAT/enhancer-binding protein β (C/EBPβ)/AEP may play an important role in NDDs. Developing its small molecule inhibitors is a promising treatment of NDDs. However, current research suggests that the pathophysiological mechanism of the C/EBPβ/AEP pathway is very complex in NDDs. This review summarizes the structure of C/EBPβ and AEP, their major physiological functions, potential pathogenesis, their small molecule inhibitors, and how C/EBPβ/AEP offers a novel pathway for the treatment of NDDs.