Research
Our Mission
An estimated 6.9 million Americans aged 60 and older are affected by Alzheimer's disease making it one of the most prevalent diseases in modern society. Few therapeutic options exist for Alzheimer’s patients including FDA-approved anti-b-amyloid immunotherapies, which can slow the progression of cognitive decline only to a limited degree. Our group is highly invested in driving the discovery of therapies aimed at preventing or halting advancement of this devastating affliction. We specialize in transgenic mouse models and cellular models of Alzheimer’s pathology including mouse lines which model deposition of b-amyloid and tau protein, biological hallmarks of Alzheimer’s, and those where neurodegeneration is induced by prion infection. Our experiments are designed to modulate Alzheimer’s pathology in these models by complete or conditional knock out or overexpression of proteins of interests which we hypothesize might contribute to neurodegeneration and progressive cognitive impairment.
Our team has extensive experience with a wide array of genetic, behavioral, microscopic, biochemical, proteomic, and transcriptomic techniques we use to characterize outcomes of our genetic manipulations in Alzheimer’s model mice. We aim to identify and characterize distinct mechanisms of neurodegeneration, which can be leveraged to develop novel therapeutic approaches for Alzheimer’s disease.
Alzheimer’s treatment may be more effective for people at highest risk
Learn more about ongoing projects below
Amyloid plaque deposition is lowest in Alzheimer's transgenic mice with the ApoE2 allele, followed by ApoE3, with ApoE4 mice having the greatest amyloid burden, consistent with what is observed in ApoE4 human carriers (Pankiewicz et al., 2017)
Astrocytes (GFAP) are more likely to display a neurotoxic (C3) phenotype following prion infection when mice lack ApoE, pointing to a role of ApoE in suppressing neurotoxic astrocyte presentation (Pankiewicz & Lizinczyk et al., 2021)
Prion monoclonal antibodies highly co-localize with a marker of lysosomal activity in vitro, suggesting mAb-Prion complexes are degraded by lysosomes (Pankiewicz et al., 2019)
Immature (green) dendritic spines are most abundant in ApoE4 mice and mature (red) dendritic spines are most abundant in ApoE2 mice (Diaz et al., 2022)
Microglia (Iba1) express low levels of phagocytic markers (CD68) after prion infection in ApoE knockout mice, indicating ApoE may be needed for effective phagocytic activity in microglia (Pankiewicz & Lizinczyk et al., 2021)
In mice overexpressing Prdx6, astrocytes tightly surround amyloid plaques, likely for direct engagement or for guiding microglial processing of plaques (Pankiewicz et al., 2020)
Current Projects
NEW AWARD! Off-the-shelf CAR-Engineered Macrophage Therapy for AD
The deposition of Aß and hyperphosphorylated tau are the two main mechanisms leading to Alzheimer’s pathology, making them the primary targets for pharmaceutical therapies. Monoclonal antibodies (mAbs) targeting Aß have emerged as effective treatments for decreasing Aß plaque deposition and slowing cognitive decline, but there are some limitations. Frequent infusions of mAbs, high costs, and possible side effects requiring discontinuation or pausing of treatment are of concern. Chimeric antigen receptor (CAR) therapies engineering T-cells of macrophages have been effective for liquid malignancies and solid tumors, respectively, in the field of oncology. This approach can be leveraged for targeting Aß in Alzheimer’s patients, with a number of modifications to the oncology-specific strategy. These will include creating HLA-blank human induced pluripotent stem cells (hiPSCs) to make them immunocompatible with any patient as well as cheaper to generate, and engineering these hiPSCs to express Aß-specific CARs which will be transdifferentiated into microglia. After creation, optimizing, and testing of these CAR-Aß-iMφs, this off-the-shelf design should become an avenue of self-sustainable, cheap, and safe Alzheimer’s treatment.
Role of Microglia in Neurodegeneration – Effect of ApoE
Like Alzheimer’s Disease, in which misfolded beta-amyloid and tau accumulate in the brain, Prion Disease is characterized by a rapid accumulation of misfolded prion protein. Thus, this investigation seeks to determine whether apolipoprotein E (apoE) expression in astrocytes and activated microglia modulate the effects of microglia in conformational neurodegenerative diseases. This project is parsing apart factors that enhance microglia phagocytosis—which helps to clear misfolded proteins—and the associated inflammatory response—which leads to neuronal death. A better understanding of apoE’s role in phagocytic vs inflammatory microglia phenotypes is enabled by prion disease mouse models, in which mice are inoculated with mouse-adapted scrapie prions. An additional goal for this project is to explore the impacts of APOE genotype on microglia activation phenotype under conditions of neurodegeneration, as human APOE4 carriers have a substantially higher risk of developing Alzheimer’s disease as well as a younger age at onset, the mechanism of which is not completely understood.
Apolipoprotein E & Alzheimer’s Disease
ApoE allele genotype is a strong predictor of developing Alzheimer’s Disease, making this one of the greatest contributors to disease risk. Though mice do not have apoE allele diversity, we are exploring the effects of possessing human apoE2, apoE3, apoE4, or the complete absence of apoE in a mouse model of Alzheimer’s Disease under conditions of monoclonal antibody (mAbs) treatment targeting beta-amyloid (Aß). Given potential vascular complications known to occur with anti-Aß mAbs, we are also testing concurrent treatment with a peptide, Aß12-28P, which interferes with apoE/Aß interactions, providing further plaque attenuation and a reduction in vascular pathology. Using mice harboring human apoE alleles, microglia and astrocytes are also being analyzed to understand how apoE genotype might impact glial activity.
In addition, part of this investigation will pertain to mitovesicles, a newly discovered extracellular vesicle stemming from mitochondria and thought to play a role in synaptotoxicity when derived from diseased neurons. Primary neuronal cultures from mice harboring each human ApoE allele will be established for in vitro testing of mitovesicles harvested from Alzheimer’s Disease neurons. The effects of these disease-compromised mitovesicles will be examined through changes in dendritic spine growth, expression of synaptic proteins, and transcriptomic changes in E2, E3, and E4 harboring neurons.
Mechanisms of Peroxiredoxin 6 Endowed Protection in AD
Beta-amyloid accumulation in the brain is the primary feature of preclinical Alzheimer’s disease, eventually leading to neurofibrillary degeneration and cognitive decline. Glial cells such as microglia and astrocytes are critical to maintaining homeostasis of numerous functions in the brain, but under conditions of neurodegenerative disorders, these glial cells may shift to cause more harm than support of neuronal survival.
Peroxiredoxin-6 (Prdx6) is a protein that is primarily expressed by astrocytes in the brain. In addition to general antioxidant enzymatic activity that promotes the repair of oxidative damage in cell membranes and its role in cellular signaling, Prdx6 appears to control astrocytic and subsequently, microglial activity surrounding beta-amyloid.
The specific role of Prdx6 in neurodegeneration has not yet been established, but our lab is interested in our hypothesis that increasing Prdx6 expression may delay Alzheimer’s progression. Preliminary data suggests that overexpression of Prdx6 in Alzheimer’s transgenic mice leads to both increased penetration of Aß plaques by astrocytic processes and enhanced phagocytic activation of microglia surrounding plaques, leading to a reduction in Aß-associated neurodegeneration. This makes Prdx6 a promising target for Alzheimer’s treatment.
Current research in our lab is focused on determining the neurodegenerative and cognitive consequences of overexpressing and knocking out the PRDX6 gene from Alzheimer’s mice, inactivating enzymatic sites Gpx and PLA2 from PRDX6 to establish the role of each in PRDX6 activity, and using transcriptomic approaches to explore the relationship between astrocytes and microglia following manipulation of Prdx6 expression.
For more published research, visit our publications page