A team of researchers creates artificial human prion in the laboratory for the first time. The breakthrough promises a deeper understanding of various infectious brain diseases.
Prions caused the brain to appear like a sponge: soggy and filled with holes. This appearance of the brain is only observable through a microscope. Hence, brain disorders brought by prions are incurable and contagious. These prion-caused neurodegenerative diseases could even be transferred from animals to humans and may hide in the brain for 30 years before becoming obvious, making it already late for treatment.
The most common type of prion disease in humans is the Creutzfeldt-Jakob disease or CJD which is usually misdiagnosed as Dementia and Alzheimer's disease. In animals, prion causes the mad cow disease and the transmissible spongiform encephalopathies or TSEs.
With the breakthrough development of synthetic human prion, experts can now understand how it affects the brain step-by-step, thereby creating a treatment that can stop prion in its tracks.
Artificial Human Prion
When proteins in the brain folded incorrectly, they can affect the other normal brain proteins. In due time, brains will develop microscopic holes until it resembles a sponge. Those incorrectly folded proteins are the human prions. Once the prion-infected brain reached the spongy characteristics, the person will develop neurodegenerative brain conditions which could even lead to death.
To understand such brain diseases, scientists had previously created artificial rodent prions. Further experiments on these rodent prions, however, failed to infect humanized mice brain models.
The current breakthrough by researchers at the Case Western Reserve University School of Medicine became the first artificially made human prion to demonstrate how incorrectly folded proteins can impact the brain.
The experiment, detailed in the journal Nature Communications, involved synthesizing human prion from a genetically engineered protein acquired from E. coli bacteria. Through the experiment, the researchers discovered the Ganglioside GM1 that demonstrated how prion-based diseases are replicated and transmitted from one host to another. The findings could give experts the springboard to develop treatments that could inhibit or block human prion replication, ultimately stopping it from further evolving to brain disorders.
"Our findings explain at the structural level the emergence of new human prions and provide a basis for understanding how seemingly subtle differences in misfolded protein structure and modifications affect their transmissibility, cellular targeting, and thus manifestation in humans," explained Jiri G. Safar, the lead author of the study and a professor of pathology and neurology at Case Western Reserve School of Medicine.
"Being able to generate synthetic human prions in a test tube as we have done will enable us to achieve a much richer understanding of prion structure and replication," Jiri added.
CJD is currently incurable and its symptoms are extremely similar to symptoms of Alzheimer's disease.
According to the National Institute of Neurological Disorders and Stroke, one person in every 1 million people worldwide is affected by CJD and about 70 percent of them die within a year. There are 350 cases of CJD per year in the United States.
In its early stage, a person with CJD develops dementia, memory loss, and problems with walking, and vision. It rapidly affects a person during the later stage where he or she suffers from mental deterioration, involuntary body movements, blindness, weakness of extremities, and coma.