In this episode Emory University and Chinese Academy of Sciences Professor Keqiang Ye talks about his fascinating and ground-breaking trail of discoveries that have revealed previously unknown mechanism responsible for the production and accumulation of damaging fragments of the APP and Tau proteins in Alzheimer’s disease (AD) and the alpha-synuclein protein in Parkinson’s disease (PD). He discovered an enzyme called AEP that cleaves Tau and alpha-synuclein into self-aggregating toxic fragments. Eliminating or disabling AEP can prevent the disease process and preserve brain function in mouse models of AD and PD. More recently, in a series of studies his laboratory has provided evidence that the generation of rogue Tau and alpha-synuclein fragments first occurs in neurons surrounding the intestines and then propagates up the vagus nerve to the brain. Moreover, his group has shown that certain species of bacteria in the gut can promote the development of the disease. Finally, Professor Ye has developed drugs that inhibit AEP or activate BDNF receptors as potential treatments for AD and PD.

LINKS

Key publications:

https://pmc.ncbi.nlm.nih.gov/articles/PMC4224595/pdf/nihms623922.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC5315368/pdf/nihms825673.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC10482867/pdf/41467_2023_Article_41283.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC8408610/pdf/EMBJ-40-e106320.pdf

https://pmc.ncbi.nlm.nih.gov/articles/PMC6951265/pdf/41422_2019_Article_241.pdf

Professor Ye’s Google Scholar page:

https://scholar.google.com/citations?user=VSP72CMAAAAJ&hl=en

Among high income countries the United States spends the most on health care and yet has the lowest life expectancy. A high percentage of Americans suffer with chronic diseases including obesity, diabetes, cardiovascular disease, mental disorders, and Alzheimer’s or Parkinson’s diseases. There are several reasons why people living in the wealthiest country have poor health all attributable to unrestrained capitalism. In this episode I talk about issues with pharmaceutical industry that contribute to the overall poor quality of health and health care in America with a focus on drugs for neurological disorders. Drug prices in the US are much higher than in other countries and prices are increasing at a rate more than 5 times the rate of inflation. Pharmaceutical companies spend nearly twice as much on marketing as on research and development and overstate their costs for drug development by ~400 percent. The US is one of only two countries that permit direct advertising of drugs to consumers. Pharmaceutical company representatives lobby doctors and congress. There are also major issues concerning clinical trials of drugs including conflicts of interest, lack of data transparency, and lack of head-to-head comparisons of a new drug with an existing drug. There are potential solutions to these problems but will require major new government regulations.

https://pubmed.ncbi.nlm.nih.gov/31034803/

https://pmc.ncbi.nlm.nih.gov/articles/PMC8649053/pdf/nihms-1751070.pdf

In this episode I talk with Professor Jason Shepherd about his discoveries concerning a fascinating protein called Arc. In response to synaptic activity Arc levels rapidly increase in postsynaptic dendrites as a result of local translation of the Arc mRNA in the dendrites. Arc plays a critical role in long-term memory although it is not necessary for learning. But perhaps the most interesting twist in the Arc story comes from the Shepherd labs discovery that Arc can self-assemble into highly ordered structures that are essentially identical to the capsids that form the coat of viruses. I talk with Jason about evidence that Arc can bind mRNAs and transfer them from one neuron to another in extracellular vesicles. These findings reveal a whole new mechanism for regulating neuronal network function. Moreover, recently Jason and his lab members have demonstrated a key role for Arc in the trans-neuronal propagation of Tau pathology which is an important advance in understanding how the neurodegenerative process spreads throughout neuronal networks in Alzheimer’s disease and other neurodegenerative disorders – and also has implications for novel approaches for halting the disease process.

LINKS:

The Shepherd laboratory page:

https://www.shepherdlab.org/

Key publications from the Shepherd lab:

https://pmc.ncbi.nlm.nih.gov/articles/PMC8041237/pdf/nihms-1661230.pdf

https://www.cell.com/action/showPdf?pii=S0092-8674%2817%2931504-0

https://pmc.ncbi.nlm.nih.gov/articles/PMC11526995/pdf/nihpp-2024.10.22.619703v1.pdf