The worst effects may not be inevitable
At Johns Hopkins Medicine, researchers have identified a compound that interrupts the very mechanism by which Parkinson's disease destroys brain cells — not merely masking its symptoms, but confronting the biological process at its root. Named PAANIB-1, the chemical blocks a protein called PAAN from dismantling neuronal DNA, preserving both cell life and motor function in mouse models. The discovery invites a quiet but profound reconsideration: that the slow erasure of self wrought by neurodegeneration may, in time, be something medicine can refuse.
- Every existing Parkinson's treatment manages decline rather than stopping it — leaving patients and physicians without a way to halt the disease's underlying destruction.
- The culprit is a protein called PAAN, which delivers a fatal blow to dopamine-producing neurons by shredding their DNA — a process so precise and relentless it had no known counter.
- Johns Hopkins researchers screened thousands of compounds to find one that could disarm PAAN's destructive function without disrupting its essential roles elsewhere in the brain.
- Mice with Parkinson's symptoms treated with PAANIB-1 held their grip — literally — matching the strength of healthy animals, while their brains showed far less neuronal damage.
- The path to human treatment remains long, but scientists are now searching for clinically safe versions of the compound and testing whether PAAN inhibition could extend to stroke and other neurodegenerative diseases.
A team at Johns Hopkins Medicine has identified a chemical compound capable of stopping the brain cell death that drives Parkinson's disease — at least in mice. Published in Cell in May 2022, the finding marks a departure from every current treatment approach: rather than softening symptoms, it targets the mechanism that kills neurons in the first place.
Parkinson's begins when a misfolded protein, alpha synuclein, accumulates in dopamine-producing brain cells and triggers a form of programmed cell death the Johns Hopkins team had previously named parthanatos. Central to this process is a protein called PAAN, which delivers the killing stroke by destroying a neuron's DNA. The problem with simply switching PAAN off entirely is that it also performs immune functions the brain depends on — making a blunt inhibitor more dangerous than helpful.
The researchers screened thousands of compounds from the Johns Hopkins Drug Library, looking for one that could block PAAN's DNA-destroying activity while leaving its other roles intact. One chemical did exactly that. They named it PAANIB-1.
The results in Parkinson's mice were measurable and striking. Animals given PAANIB-1 maintained grip strength comparable to healthy mice, while untreated animals showed the expected motor decline. Brain tissue from treated mice revealed significantly less neuronal damage — suggesting the compound had genuinely interrupted the disease's progression.
The researchers now face the longer work of finding compounds safe for human use and exploring whether PAAN inhibition might also apply to stroke and other neurodegenerative conditions. The proof of concept, however, is in place: the cell death cascade that defines Parkinson's can be interrupted, and the damage it causes may not be inevitable.
A team at Johns Hopkins Medicine has identified a chemical compound that stops the cascade of brain cell death in Parkinson's disease—at least in mice. The finding, published in Cell in May 2022, offers a fundamentally different approach to treating the disease than anything currently available. Where existing drugs merely slow or soften symptoms, this compound targets the actual mechanism that kills neurons, suggesting that the progressive damage characteristic of Parkinson's may not be inevitable.
Parkinson's develops when a misfolded protein called alpha synuclein accumulates inside brain cells that produce dopamine, the neurotransmitter responsible for smooth movement and emotional regulation. As these malformed proteins clump together, they trigger a form of programmed cell death that researchers at Johns Hopkins had previously identified and named parthanatos—from the Greek word for death. The process is relentless. Once it begins, no known drug can stop it.
The key to halting this cascade, the researchers discovered, lies in blocking a protein called PAAN. In earlier work, Valina Dawson and her colleagues had shown that PAAN delivers the final blow to neurons damaged by alpha synuclein, destroying the cell's DNA and killing it. The challenge was that PAAN has other jobs in the brain—immune functions, for instance—that are essential to keep the organ healthy. Any drug that simply shut down PAAN entirely would cause more harm than good.
So the team set out to find a chemical that could block PAAN's ability to destroy DNA while leaving its other critical functions intact. They screened thousands of compounds from the Johns Hopkins Drug Library, exposing DNA strands to PAAN in the presence of each chemical. When a compound prevented PAAN from breaking down the DNA, they had a candidate. One chemical stood out: it blocked PAAN's destructive activity without affecting anything else. They named it PAANIB-1, for PAAN inhibitor 1.
In mice engineered to develop Parkinson's symptoms, the difference was measurable and striking. Researchers tested grip strength by seeing how long each animal could hold onto a lever with its front paws. Untreated mice with Parkinson's showed the expected weakness. But mice given PAANIB-1 maintained grip strength comparable to healthy mice—suggesting the compound had halted the motor decline linked to brain cell death. When the researchers examined the brains of treated animals afterward, they found significantly less neuronal damage than in untreated controls.
The work represents a proof of concept: it is possible to intervene in the cell death pathway that drives neurodegeneration, and the worst effects of the disease may not be written in stone. But the journey from mouse to human is long. The researchers are now screening additional compounds that could be safely used in people, with the goal of developing a drug that works the same way PAANIB-1 does in rodents. They are also investigating whether blocking PAAN might help in other neurodegenerative conditions, including stroke. The real test will come when these findings move from the laboratory into clinical trials.
Citas Notables
Studies like this show that there is hope in intervening with neurodegenerative disease, and that its worst effects may not be inevitable.— Valina Dawson, professor of neurology at Johns Hopkins University School of Medicine
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Why does it matter that this compound leaves PAAN's other functions alone?
Because PAAN does more than just kill cells. It's involved in immune responses in the brain. If you shut it down completely, you'd lose that protection. You'd trade one problem for another.
So the researchers had to be surgical about it.
Exactly. They needed to find the one thing PAAN does that kills neurons—the DNA destruction—and block only that. It's like disarming a bomb without cutting the wrong wire.
The grip strength test seems almost simple.
It is simple, which is why it works. You can't fake grip strength. If the mouse can hold on like a healthy mouse, the motor neurons are still firing. The cell death has stopped.
What happens next? Do they just try this in humans?
Not yet. They need to find compounds that work in human brains without toxicity. PAANIB-1 was the proof—the proof that the strategy works. Now they're looking for the drug that could actually be given to patients.
And if they find one?
Then Parkinson's becomes a disease you might actually be able to stop, not just slow down. That changes everything.