Chilean scientists create and patent new and innovative therapy for deadly neurodegenerative disease
07-30-2020
07-30-2020
Claudio Hetz and René Vidal from the Millennium Institute of Biomedical Neuroscience (BNI) of the U. de Chile took eight years to develop it and now they have managed to register it in the US and the Netherlands.
Huntington's disease is a hereditary genetic neurodegenerative pathology that occurs due to a genetic mutation that affects a specific group of neurons and that is caused by the accumulation in the brain of a protein called huntington.
Until now, it does not have an effective treatment and after the appearance of uncontrolled movements, cognitive damage, behavioral disturbances and finally death follow.
"Unlike other neurodegenerative diseases, Huntington is 100% genetic and mutations in the huntingtin gene can appear spontaneously. For example, a person who does not have it may have a child who develops the disease. Now, if someone presents the pathology, their offspring will have a 50% chance of having it and their grandchildren a 75%. Furthermore, unlike Alzheimer's, in 10 years a patient dies from Alzheimer's, in Huntington's case they can be ill for up to 20 years, suffering from progressive cognitive deterioration ”, explains Claudio Hetz, director of the Millennium Institute of Biomedical Neuroscience (BNI) of the Faculty of Medicine of the University of Chile.
Scientists from this center, including René Vidal, also a researcher at the Integrative Biology Center (CIB) of the Universidad Mayor, led an eight-year work in which they managed, from basic science, to develop an innovative therapy that was already patented and it was tested in the United States and the Netherlands with human cells with very good results.
Protein in the laboratory
Hetz and Vidal's first work focused on reviewing brain tissue samples from people who died of Huntigton's disease.
They used a brain sample bank maintained by Harvard University in the US and a clinical study conducted in Chilean patients, and from these sources, they made their first discovery.
For two years, they recruited 40 patients from the Center for Movement Disorders (Cetram) led by the neurologist Pedro Chaná and who also participate in the international program Enroll - HD, the largest clinical data platform worldwide for this disease and whose objective is to accelerate the development of therapies for this pathology.
They were measured for the presence of a protein called IGF2 in blood samples and were able to verify that their levels were low and the more the disease progressed, the less they had of this protein.
"We observe that patients suffering from this disease show a very significant decrease in the levels of a protein called IGF2 in brain tissue and in blood samples. Therefore, it can also be a powerful biomarker of disease. Even when analyzing the brain of subjects who died from this disorder, this protective protein was almost completely lost. This means that we can predict the state of progress of the disease in which the person is, it works as a risk factor, "says Vidal.
What is IGF2? “It is a protein that is naturally present in our body, and its expression decreases as we age. This protein is capable of improving the connectivity of neurons and promoting the balance of the components within them involved in the elimination of toxic proteins that can generate disease, "explains René Vidal.
This protein is produced mainly in endothelial cells, which transfer nutrients to the brain from the blood. This protein is delivered to the neurons so that they maintain their functions such as their activity and connection, favoring their survival.
"This protein has positive effects at all levels, it keeps brain stem cells healthy, it also has regenerative effects," adds Hetz.
Modified virus
Proven that the lack of this protein affects the health of the neurons of patients with this disease, Hetz, Vidal and the Spanish doctor Paula García Huerta developed a therapy that in the animal model gave good results.
In simple terms, they used a very small virus of the adeno-associated type that measures just 20 nanometers, genetically modified and inside, they introduced the IFG2 gene.
This virus was administered to transgenic animals that have a Huntington's disease-like mutation (three different models of the disease). The result? Not only were they able to reestablish the levels of this protective protein, but they also eliminated the accumulated toxic proteins as garbage.
“We ended up developing a gene therapy strategy and we patented it. That means that it can be transformed into a technology. The vice-rectory of the U. de Chile is now looking for companies that license this technology for therapeutic development, "says Hetz.
Mother cells
At the Buck Institute in California (United States) where Hetz is an adjunct professor, at Groninger University in the Netherlands, they did another part of this research: they took skin samples from patients with this disease, transformed them into stem cells and then into neurons human to study this disease and their behavior by adding the protein that is decreased in them.
"These are not artificial or experimental studies, but we were able to use laboratory-grown human neurons, which are generated using inducible stem cell technology," says Hetz.
Together with the Genzyme laboratory, which is the second technology company associated with the study, the scientists used genetically modified viruses to introduce them into neurons "so that they begin to produce high amounts of IGF2 in the brain. And so begin to spread this factor and in theory improve the state of health. "
The BNI director explains that there are very few investigations in Chile that come out of the laboratory, work on animals and end in a clinical analysis on patients and also develop experimental therapy. “For us at BNI it is a very important milestone because, in some way, through collaborations we managed to generate a multidisciplinary study, which allowed us to find a new factor: IGF2, which has potential in terms of developing future therapies. This will probably be tested in Alzheimer's, ALS, in Parkinson's, where it will also have positive effects, "concludes Hetz.
