A groundbreaking discovery has ignited fresh hope in the fight against Parkinson’s disease, suggesting that drugs already in clinical development for other conditions could be repurposed to halt the relentless neurodegeneration that defines the illness. Scientists at University Hospitals, Case Western Reserve University, and the Cleveland VA Medical Center have demonstrated that blocking a single enzyme, 15-PGDH, powerfully shields dopamine-producing neurons from destruction across multiple preclinical models, restoring motor function and normalizing the brain’s internal redox environment. The findings, published in Redox Biology, illuminate an entirely new therapeutic avenue for the more than ten million people worldwide living with this progressive movement disorder.
Parkinson’s disease is characterized by the gradual loss of dopaminergic neurons in the substantia nigra, a process driven by a toxic blend of protein aggregation, mitochondrial dysfunction, and unrelenting oxidative stress. While existing treatments temporarily replenish dopamine signaling, none address the underlying cellular collapse. The enzyme at the center of this new work, 15-hydroxyprostaglandin dehydrogenase (15-PGDH), sits at a critical metabolic checkpoint: it degrades prostaglandin E2, a lipid signaling molecule, thereby tipping the cellular balance toward a pro-oxidant state. In a healthy brain, 15-PGDH activity is tightly controlled, but the team discovered that its levels are abnormally elevated in autopsied brain tissue from Parkinson’s patients, as well as in three distinct mouse models of the disease, including one driven by pathological α-synuclein accumulation that mimics the human condition.
The researchers deployed both genetic and pharmacological strategies to inhibit 15-PGDH. In one arm of the study, mice genetically engineered to lack the enzyme were completely shielded from the neuroinflammatory cascade and motor deficits typically induced by Parkinsonian toxins. In a parallel set of experiments, oral administration of a small-molecule inhibitor called SW033291—originally developed in the laboratory of co-senior author Sanford Markowitz—penetrated deep into the brain, achieving near-total suppression of 15-PGDH enzymatic activity. Treated animals maintained dopamine neuron numbers, preserved normal movement coordination, and displayed a striking dampening of glial activation, a hallmark of neuroinflammation that perpetuates neuronal damage.
Dissecting the molecular circuitry downstream of 15-PGDH, the team uncovered a trio of previously unrecognized mediators that collectively orchestrate dopaminergic cell death. Inhibition of the enzyme led to a sharp downregulation of lipocalin-2 (Lcn2), a secreted protein recently implicated in amplifying neurodegeneration; a reduction in the pro-inflammatory cytokine interleukin-1β; and a marked suppression of Cybb, the gene encoding the catalytic subunit of the reactive oxygen species-generating NADPH oxidase complex Nox2. This three-pronged effect effectively restored redox homeostasis, breaking a vicious cycle in which oxidative stress triggers inflammation that in turn generates more free radicals. “This provides new mechanistic insight into how 15-PGDH inhibitors could target and prevent neurodegeneration in Parkinson’s disease,” said Markowitz, the Ingalls Professor of Cancer Genetics at Case Western Reserve.
One of the most surprising and clinically significant outcomes was that neuroprotection occurred without any change in the accumulation of pathologically phosphorylated α-synuclein, the insoluble protein clumps long believed to be the primary toxic insult in Parkinson’s. This mirrors the team’s earlier observation in Alzheimer’s models, where 15-PGDH inhibition shielded synapses and memory despite unabated amyloid pathology. Together, these results build a compelling case that the brain’s intrinsic damage-response and inflammatory machinery may be a more tractable therapeutic target than the misfolded proteins themselves, and that 15-PGDH sits at a master regulatory node capable of disarming that machinery.
The translational path is unusually swift. The inhibitor MF-300, a next-generation 15-PGDH blocker, has already successfully completed Phase 1 clinical trials for peripheral indications with a clean safety profile. Moreover, humans born with biallelic inactivating mutations in the HPGD gene exhibit no serious developmental or cognitive deficits—the only consistent physical trait is digital clubbing, a harmless enlargement of the fingertips. This natural human genetics experiment provides powerful validation that chronically knocking down the enzyme is well-tolerated, removing a major obstacle that typically stalls drug development for central nervous system targets.
The research team, co-led by Andrew A. Pieper, the Morley-Mather Chair of Neuropsychiatry at University Hospitals, now plans to map the upstream signals that drive 15-PGDH overexpression in the Parkinsonian brain and to further dissect the intersecting Lcn2, IL-1β, and Nox2 pathways with cell-type-specific precision. Pieper noted that the ability of a single enzyme inhibitor to simultaneously normalize oxidative balance, quell inflammation, and prevent neuronal loss “encourages us to think that 15-PGDH inhibitors could be repurposed for Parkinson’s disease in a timeframe far shorter than starting from scratch.” With pharmaceutical companies already developing 15-PGDH inhibitors for conditions ranging from bone marrow recovery to inflammatory bowel disease, the infrastructure exists to pivot rapidly toward neurodegenerative indications. For a field that has long sought a therapy capable of doing more than simply managing symptoms, this convergence of mechanistic clarity and clinical readiness represents a genuine inflection point.
Subject of Research: Neuroprotective effect of inhibiting the enzyme 15-PGDH in Parkinson’s disease models
Article Title: Inhibiting 15-PGDH restores redox homeostasis and confers neuroprotection in Parkinson’s disease
News Publication Date: 2026
Web References: https://www.sciencedirect.com/science/article/pii/S2213231726002843
References: Redox Biology, 2026; DOI: 10.1016/j.redox.2026.104285
Image Credits: University Hospitals / CWRU
Keywords: Parkinson’s disease, 15-PGDH, neuroprotection, neuroinflammation, redox homeostasis, drug repurposing, alpha-synuclein, oxidative stress
