Publications

Our papers

An up-to-date list of citations is on PubMed. Alice's Google Scholar profile and her CV are also available.

Highlighted papers

Secreted GPNMB enhances uptake of fibrillar alpha-synuclein in a non-cell-autonomous process that can be blocked by anti-GPNMB antibodies

Neuron 2026Marc Carceles-Cordon et al.

This 2026 follow-up paper demonstrates that GPNMB can be cleaved off the cell surface, and the extracellular domain (ECD) can do everything that we reported full-length GPNMB to do in 2022. Moreover, we present evidence suggesting that the source of the GPNMB ECD is microglia, which upregulate GPNMB secretion in response to neuronal damage. Finally, we show that anti-GPNMB antibodies can block uptake of aSyn fibrils in neurons and prevent the subsequent formation of aSyn pathology.

GPNMB confers risk for Parkinson's disease through interaction with α-synuclein

Science 2022Maria Diaz-Ortiz, Yunji Seo et al.

This 2022 paper demonstrates that GPNMB is the target gene of a Parkinson's disease GWAS locus, that higher GPNMB expression is associated with PD risk, and that GPNMB is necessary and sufficient for uptake of aSyn fibrils in cellular models (iPSC-derived neurons). Effects may be through a protein-protein interaction between aSyn and GPNMB.

Blood α-synuclein separates Parkinson's disease from dementia with Lewy bodies

Annals of Neurology 2025George Kannarkat, Rebecca Zack et al.

Clinicians learn the "one year rule" — if a patient develops cognitive issues more than one year after motor symptoms, they are diagnosed with PD, while if they develop cognitive problems before or within the first year after motor symptoms, they are diagnosed with DLB. If that sounds arbitrary to you, you're not alone. But this 2025 study completely changed Alice's prior belief that PD and DLB are the same disease — because it turns out that conformations of alpha-synuclein may distinguish the two.

Cognitive heterogeneity in Parkinson's disease: a mechanistic view

Review in Neuron 2023Marc Carceles-Cordon, Dan Weintraub, Alice Chen-Plotkin

A review that captures a lot of how we're thinking about the synucleinopathies — Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. We are actively trying to target many of these mechanisms now.

The things we learned the hard way

Some experiments work out the way that you expect. Some do not. Some projects are publishable. Some are not.

Here is a place we are putting data that we think is valuable, but not publishable. Some of it is negative data — biomarkers that did not replicate. Some of it is data that is too confusing — things too noisy to translate clinically. Some of it is information that you may just want: quality control procedures, experience with various assays, slides from talks.

MJFF PPMI data, May 2015

Slides showing our data for measures of epidermal growth factor (EGF) and apolipoprotein A1 (ApoA1) in plasma samples from the international Michael J. Fox Foundation Parkinson's Progression Marker Initiative cohort. EGF measures vary greatly by clinical site of origin, even with the rigorous standard operating procedures that PPMI uses. In these same samples, ApoA1 measures, in contrast, do not. Bottom line: from the perspective of biomarker development, some proteins will be better candidates by virtue of their stability to variation in sample collection, storage and processing.

Somalogic quality control

Quality control data from our experience with the Somalogic aptamer platform. The first slide shows the analytes that "failed" quality control (>20% CV across any of three sets of triplicates — 9 QC samples total). The second shows whether the three sets of triplicates overlapped with respect to failures. The third and fourth show whether the platform performs similarly across space (Penn vs. Boulder) and time (2013 vs. 2015).

Derek Denny-Brown lecture slides

From Alice's presentation in October 2018 when she was awarded the Derek Denny-Brown Award from the American Neurological Association. They provide an overview of what the lab was doing in its first 8 years.

Advancing PD therapeutics — NINDS workshop

Slides from Alice's overview of the April 2024 NINDS workshop aimed at advancing therapeutics development in Parkinson's disease. Initiated by the NIH-NINDS, the meeting was co-chaired by Alice and Bill Martin, Global Therapeutic Area Head for Neuroscience, J&J. The workshop paper is here.