High Density Lipoproteins and Alzheimer’s disease
by Ashley Martinez
High Density Lipoproteins (HDL) are often referred to as “good” cholesterol because they travel throughout the body picking up excess cholesterol to be delivered to tissues for energy. The drivers of these particles are called apolipoproteins. The most abundant apolipoprotein found on plasma derived HDL particles is apolipoprotein A-I, or apoA-I. We are interested in apoA-I because of its cardioprotective and neuroprotective functions. ApoA-I has been found on HDL particles in CSF, as well as apolipoprotein E, or apoE. ApoE is the principal cholesterol carrier in the brain and is heavily implicated in Alzheimer’s Disease.
HDL particles in human plasma have been well characterized by their physical, chemical and biological properties. However, much less is known about HDL particles in CSF or their association with AD pathology. Additionally, there is a gap in knowledge between brain-derived HDL and plasma-derived HDL.
Conferences and Awards
Diabetes and Obesity Research Institution (DORI) 7th Annual Symposium
I study HDL particles in human cerebrospinal fluid (CSF) and their association with AD biomarkers in a cohort of non-demented elderly participants recruited from the USC ADRC and HMRI Aging program. With the help of collaborators from the Children’s Hospital Oakland Research Institute (CHORI), we were able to define HDL particles subspecies by size in human plasma and CSF samples from this cohort using an analytical method called Ion Mobility. Size distribution of HDL subpopulations in these samples were analyzed against variables such as performance on cognitive measure and CSF Abeta42, a biomarker for amyloid deposition in the brain.
We hypothesized that smaller ApoA-I containing HDL particles in CSF associate with lower beta amyloid deposition and better performance on cognitive measures. In contrast, we posit that larger ApoE containing HDL particles associate with the APOE4 genotype and greater beta amyloid deposition.
I am primarily interested in characterizing HDL subspecies in human CSF by protein and lipid content, as well as their functional properties. On February 26, 2020, I was awarded 2nd place for the trainee poster session at the DORI 7th Annual Symposium.