Aβ production and clearance by protein kinase C

Alzheimer's disease is the most common form of dementia in the elderly population. One of the most notable pathological characteristics of Alzheimer's disease is the aggregation of amyloid β-peptide (Aβ) plaque from the processing of amyloid precursor protein (APP) in neurons, which leads to neurodegeneration and cognitive dysfunction. Recently, numerous studies suggest that activation of protein kinase C (PKC) reduces the production of Aβ plaque by promoting α-secretase activity, which is the enzyme that converts APP to the secretory form of amyloid precursor protein (sAPPβ). One isoform of PKC, PKCβ, is known to actively play a role in the clearance of Aβ plaque by activating endothelin converting enzyme type 1 (ECE-1), which can degrade Aβ plaque. Therefore, PKC can activate α-secretase and ECE-1 to limit the production of, and actively degrade, Aβ plaque, respectively. Here we discuss in more detail the various roles that PKC can have in Aβ plaque production and clearance and its implication in Alzheimer's disease. Moreover, PKC is a downstream signaling molecule of G-protein coupled receptors (GPCRs), which have also recently been shown to be implicated in the pathogenesis of Alzheimer's disease. Therefore, recent research efforts suggest that further investigation on the pharmacological regulation of PKC, possibly via GPCRs, may lead to the identification of clinically useful targets to treat Alzheimer's disease.