Targeting of PCSK9 in the Management of Alzheimer's Disease: Expanding the New Potential Key Player.

Alzheimer's disease (AD) represents the most common cause of dementia in the elderly population worldwide. However, most of the anti-AD medications did not resolve the underlying neuropathology. Consequently, targeting other signaling pathways may be helpful in the management of AD. Particularly, preprotein convertase subtilisin/kexin type 9 (PCSK9), which is a regulator protein of low-density lipoprotein (LDL), is intricate in the pathogenesis of AD. Normally expressed PCSK9 in the brain plays a critical role in the regulation of neuronal differentiation and apoptosis, and degradation of LDL receptors (LDLRs). However, exaggerated brain PCSK9 via induction of inflammation and oxidative stress and related neurodegeneration may induce AD development. Therefore, neuronal PCSK9 has dual role in the CNS. Nevertheless, the exact role of PCSK9 in AD neuropathology is still elusive. Therefore, in the review, we try to revise and discuss the potential role of PCSK9 in the pathogenesis of AD, and how targeting of this protein may be helpful in the management of AD.