Scientists at the University of Southern California (USC) have identified a significant link between elevated cPLA2 activity and the risk of Alzheimer's disease, particularly among individuals carrying the APOE4 gene, the most potent known genetic risk factor for this condition. While many who possess the APOE4 variant do not develop Alzheimer's, those exhibiting higher levels of cPLA2 activity are more susceptible to the disease.
Recognizing that cPLA2 plays a role in maintaining healthy brain function, the research team aimed to mitigate its detrimental effects without completely inhibiting the enzyme. A key challenge was to discover compounds small enough to penetrate the blood-brain barrier effectively.
Senior author Hussein Yassine, who directs the Center for Personalized Brain Health at USC's Keck School of Medicine, stated, "In this study, we identified compounds that act selectively on cPLA2, with minimal effects on related PLA2 enzymes that are important for normal cellular function." The compounds demonstrated a reduction in cPLA2 activity at low concentrations across both cell-based and animal models, highlighting their potential effectiveness in brain-relevant systems.
Innovative Screening for Drug Candidates
The research team employed advanced computational techniques to screen billions of molecules, focusing on those predicted to selectively target cPLA2, effectively cross the blood-brain barrier, and maintain activity in biologically relevant conditions. These screening methods were developed by Vsevolod "Seva" Katritch from USC Dornsife College of Letters, Arts and Sciences and the USC Michelson Center for Convergent Bioscience.
Following the screening, pharmacologist Stan Louie from the USC Alfred E. Mann School of Pharmacy led the preparation of the selected compounds for testing in animal models, assessing their ability to reach the brain.
Among the candidates, one cPLA2 inhibitor stood out, successfully reducing harmful cPLA2 activation in human brain cells subjected to Alzheimer's-related stress.
Encouraging Early Findings from Animal Studies
In experiments with mice, the leading compound crossed the blood-brain barrier and positively influenced neuroinflammatory pathways associated with Alzheimer's disease. These findings suggest that selectively inhibiting cPLA2 could be a promising avenue for treating neurodegenerative disorders.
"Our goal is to determine whether targeting inflammation can modify Alzheimer's risk, especially in APOE4 carriers," Yassine noted. "The next phase will focus on rigorously evaluating the safety, feasibility, and significance of modulating this pathway for human health."
This research was supported by various grants from the National Institute on Aging and other organizations, showcasing the collaborative effort behind this groundbreaking work.
