The Role of PGRN in Alzheimer's Disease.

Progranulin (PGRN), a multifunctional growth factor expressed in various tissues, is involved in a diversity of physiologic and pathological processes, including cell proliferation, wound healing, and modulation of inflammation. Interest in the role of progranulin in the brain has increased dramatically since mutations in GRN, which encodes for the protein PGRN, are associated with the pathogenesis of Alzheimer's disease (AD). A great many of studies suggest that PGRN participates in AD pathogenesis through diverse pathways, including Aβ deposition and clearance, intraneuronal deposition of phosphorylated tau, neuroinflammation, and neuronal survival. Decreased GRN mRNA levels can be detected in the parietal lobe of patients clinically diagnosed with AD; more importantly, emerging data support that serum or plasma PGRN can act as a biomarker for AD. By understanding PGRN in a wider context, we may be better able to depict its role in AD and then provide a therapeutic strategy for AD.