Brain parasites found in cat poo could be ‘trained to spit out special proteins’ to TREAT Alzheimer’s and Parkinson’s
A PARASITE found in soiled cat litter could be used to treat Alzheimer’s and Parkinson’s, scientists say.
Researchers discovered that Toxoplasma gondii – commonly present in feline poo – can be successfully engineered to deliver proteins to the brain in mice.
In the past, human neurological healthcare has been limited by the difficulty of delivering targeted treatment across the blood-brain-barrier and into the correct location inside neurons.
But this world-first discovery “represents an exciting new field of research” as it can do just that.
Professor Oded Rechavi, of Tel Aviv University, Israel, said: “Evolution already ‘invented’ organisms that can manipulate our brains.
“I think that instead of re-inventing the wheel, we could learn from them and use their abilities.”
Toxoplasma gondii is believed to be carried in a dormant state by a third of the population worldwide.
Experts say it can now travel from the digestive system to the brain, where it secretes its proteins into neurons.
It has evolved to cross the blood-brain-barrier and placenta, and poses a risk to pregnant women as it can cause miscarriages – leading to advice that expectant mothers should avoid handling litter trays if their cat hunts for prey outdoors.
Most neurological conditions, including Alzheimer’s, Parkinson’s and Rett Syndrome, have been linked in some way to protein dysfunction, but scientists have struggled to address the problem at the source.
The potential to use engineered brain parasites to deliver treatment across the blood-brain-barrier was described as “pioneering” and a global breakthrough – although it is still years away from becoming reality.
International researchers, led by the University of Glasgow, Scotland, in collaboration with Tel Aviv University, wanted to establish if the parasite could act as a medicine delivery vehicle to disease-affected brain cells.
The study team first had to find out whether they could effectively make the parasites produce the therapeutic proteins, and then test whether the parasites would be able to “spit” the proteins back out into affected brain cells.
Researchers focused on engineering the parasites to deliver the MeCP2 protein, which has already been proposed as a promising therapeutic target for Rett syndrome – a debilitating neurological disorder caused by mutations in MECP2 gene.
The parasite successfully produced the protein, and then delivered it to the target cell location in brain organoids and in mice models.
Further experiments will take place to engineer the parasites so they die after delivery, to prevent additional cell damage.
The findings are published in the journal Nature Microbiology.
‘THINKING OUT OF THE BOX’
Scientists suggest that with further research and testing, parasites could potentially play a role in the delivery of therapeutic proteins to the brain.
Professor Lilach Sheiner, one of the leading authors of the study from the University of Glasgow’s School of Infection and Immunity, said: “This is a blue-sky project where our collaborative team was thinking out of the box to try to tackle the long-standing medical challenge of finding a way to successfully deliver treatment to the brain for cognitive disorders.
“The concept is not without challenges, considering the dangers involved with Toxoplasma infection.
“For our work to become a treatment reality, it will require many more years of careful research and development to enhance efficiency and improve safety.”
Other medical breakthroughs that could help eradicate Alzheimer's
WHILE experts have warned that dementia diagnoses in England have reached record numbers, there have been a number of recent advances against the brain-robbing disease.
From “game-changing” drugs gaining approval to blood tests that can spot the condition years before symptoms, here are other major Alzheimer’s breakthroughs:
- A “game-changing” Alzheimer’s drug called donanemab, that slows mental decline by up to 60 per cent has been approved in the United States. A UK decision on whether the medicine will become available to patients in the UK with early symptoms is expected imminently.
- A blood test that detects Alzheimer’s up to 15 years before symptoms emerge is set to be made free on the NHS within a year. The new test is cheaper, easier and at least as accurate as the current diagnosis options and works by measuring levels of a protein in the blood called p-tau217.
- Researchers have developed a first-of-its-kind test that could predict dementia up to nine years before a diagnosis, with 80 per cent accuracy. It involves analysing a network of connections in the brain when it’s in “idle mode” to look for very early signs of the condition.
- Scientists have also put AI to the test, developing machine learning models that were able to spot early warning signs of the memory-robbing condition up to seven years before Alzheimer’s symptoms appear.
- A woman who has evaded Alzheimer’s disease despite half her relatives getting it could hold the clues to how to prevent it, with scientists pinpointing a particular gene which they think could help prevent Alzheimer’s from progressing.
- A single-dose nasal spray treatment could ‘wash away’ build ups of toxic proteins associated with Alzheimer’s disease from brain cells and improve memory, scientists say.
Toxoplasma gondii can cause toxoplasmosis – an infection you can catch from the poo of infected cats or infected meat.
Many people won’t experience any symptoms at all, but it can cause a high temperature, headache, sore throat, aching body, swollen glands, tiredness and feeling or being sick.
Toxoplasmosis is not usually serious and normally gets better on its own.
But it can cause more serious problems if you are pregnant, have a weakened immune system or experience severe symptoms like confusion, blurred vision or slurred speech, the NHS warns.
If you are concerned, speak to your GP.