Thursday, November 30, 2017

Nilotinib and Parkinson's Disease


Parkinson’s disease: a diagnosis that marks the beginning of end of a patient’s motor functions. It is the most common of the neurodegenerative diseases, and in terms of treatment, also happens to be the most elusive. The disease is characterized by the unexplained death of dopaminergic neurons in the substantia nigra (SN) portion of the brain. Dopamine is vital for control of motor function, thus the death of these neurons begins the start of the disease. Thus far, we have only learned how to treat the symptoms of the disease. Patients are treated with Levodopa, a precursor to dopamine, coupled with carbidopa to ensure its safe delivery to the brain and even distribution to the central nervous system.
Patients diagnosed with Parkinson’s disease will experience resting tremors (especially in the hands), bradykinsesia (slowness of movements), limb rigidity, and gait and balance issues. In addition to motor function loss, there are non-motor symptoms as well. These include, but are not limited to: depression, loss of sense of smell, and cognitive impairment.
Molecular causes of the disease are largely unknown. Only 10-15% of cases can be attributed to genetics, while the remaining are sporadic with no known cause. There are currently one million people in the United States living with PD. Because of the late onset of symptoms, the majority of cases are only caught when the symptoms have begun and the patient’s motor function is already degenerating, they are already late stage patients. This gives doctors and PD researchers no time to focus on prevention or see what exactly is causing it.      
Nilotinib, advertised as Tasigna, is currently approved for treating newly diagnosed adult patients with Philadelphia chromosome–positive chronic myeloid leukemia (Ph+ CML) in chronic phase (CP). Studies have shown that Nilotinib decreases levels of alpha-synuclein in the brain as well as the blood. The primary component of the Lewy Bodies found in the substantia nigra, the site of this neuron death, is alpha-synuclein. Alpha-synuclein activates Abl, a tyrosine kinase that has many functions, including apoptosis. In trials with mice, the drug was found to not only increase dopaminergic levels and improve motor function, but also to clear cytosolic debris in SN neurons.
Is Nilotinib scraping the surface of new treatment options for Parkinson’s? Are we finally understanding the molecular events that lead up to this devastating neurodegenerative disease?
Resources
Dauer, W., & Przedborski, S. (2003). Parkinson’s Disease: Mechanisms and Models. Neuron,
39, 889-909. Retrieved November 16, 2017.
Hebron, M. L., Lonskaya, I., & Moussa, C. E. (2013). Nilotinib reverses loss of dopamine
neurons and improves motor behavior via autophagic degradation of  -synuclein in           
Parkinsons disease models. Human Molecular Genetics, 22(16), 3315-3328.
doi:10.1093/hmg/ddt192
Karuppagounder, S. S., Brahmachari, S., Lee, Y., Dawson, V. L., Dawson, T. M., & Ko, H. S.
(2014). The c-Abl inhibitor, Nilotinib, protects dopaminergic neurons in a preclinical
animal model of Parkinsons disease. Scientific Reports, 4(1). doi:10.1038/srep04874
Pagan, F., Hebron, M., Valadez, E. H., Torres-Yaghi, Y., Huang, X., Mills, R. R., . . . Moussa, C.
(2016). Nilotinib Effects in Parkinson’s Disease and Dementia with Lewy Bodies.
Journal of Parkinson's Disease,6, 503-517. Retrieved November 15, 2017.
Parkinson Disease Treatment & Management. (2017, November 15). Retrieved November 16,
Tasigna. (n.d.). Retrieved November 16, 2017, from https://www.hcp.novartis.com/products/ta
What Is Parkinson's? (2017, October 18). Retrieved November 16, 2017, from http://www.parkinson.org/understanding-parkinsons/what-is-parkinsons
By Savannah Tucker, Bachelor of Public Health Student, University of Kentucky

16 comments:

  1. This is a very interesting topic. I am to know what are the long term effects of this newly synthesized medicine. With further researcher hopefully there will be a cure to PD.

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  2. Neurodegenerative diseases are some of the worst diseases we are dealing with in the society. It is very hard to understand the nervous system and because everyone's nervous system differs from one another it makes it very difficult to find similarities amongst all patients and it makes it very difficult for researchers to identify the cause of PD. I really hope with more research we will figure out the causes of all neurodegenerative diseases some day.

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  3. This is a very interesting blog and an important topic. I actually knew someone with Parkinson's disease and it was sad to see her deteriorate the way that she did. Is this the only drug that has been approved for use and if so are there any others that are in the trial/research stages? Im sure this is a very difficult disease to handle/treat because of the system it impacts. However, I am glad they are continuing to do work to treat it.

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    1. Yes this is very devastating disease, my Grand father had it. As i mentioned in class, Monoclonal antibodies against alpha-synuclein is currently in trial.

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  4. With dopamine being a key player in the development and progression of this neurodegenerative disease, I wonder how endocrinologists are responding to Parkinson's disease and if any collaborations can/have been made to better explore this relationship. I know that with any hormone signaling pathway that regulation can be in part governed by receptors for these neurotransmitter hormones, but also by circulating levels. I know that neurogenesis and neuroplasticity is a more difficult hurdle to tackle, but in knowing how these endocrine mechanisms work I wonder if there is a potential for preventative measures of disease development in addition to current efforts to treat Parkinson's.

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    1. One of the problem is that brain cells producing dopamine is dying so unfortunately high amount of stimulating hormone wont help. Also endocrine works systemically (though blood) this means it will all organs and not just brain.

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  5. I agree, that dopamine precursors and dopamine agonist simply cure the symptoms. And i do believe alpha synuclein accumulation is what causing the problem. Removal or preventing the accumulation seems like the only way to treat PD.

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  6. Hopefully this drug will get further testing to understand whether or not it could advance the treatment for Parkinson's Disease! Neurodegenerative diseases are difficult to deal with, and any progress is a great step forward for the neuro community.

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  7. Always an interesting topic to discuss! It is important for current and future research to look at genetic factors that could lead to PD, and alpha-synuclein aggregation seems to be a favorite. That is great, but I'm not sure that reducing alpha-synuclein in patients that already have PD would have a great effect in humans. I do think that if given at an early stage of PD (maybe with patients who show non-motor symptoms and have yet to show motor symptoms) it could be effective. I'm excited to see where this goes as studies progress.

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    1. Some examples of non-motor (premotor) symptoms associated with PD: Impaired olfaction, sleep disturbances, constipation (microbiome?), and depression. These may seem like common things, but it is pretty rare to see these presented together.

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  8. It will be interesting to see what direction we take in the fight against Parkinson's Disease. I hope that we will find a way to do more than simply treat symptoms. But it is good to see that progress is being made to find some relief for those suffering from the disease.

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  9. I think all brain disorders are so interesting because we can't seem to figure out exactly what they are or how they work. I hope this drug can help to treat some Parkinson's disease patients as we continue to look for a way to cure the disease.

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  10. i hope the drug gets more time and chances to test the benefits on Parkinsons since it effects many people

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  11. This was a good case study on PD. Hopefully the drug will be tested on more and they will be able to provide a better understanding of the drugs and PD.

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  12. Aman Patel - I found interesting the that drug was actually being tested for another disorder but happened to find positive effects that might help patients with parkinson's

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  13. In the intro to neuroscience class I am taking we talked briefly about a treatment University of Kentucky researchers actually worked on, using the glial derived neurotropic factor (GDNF) gene. GDNF therapy has been shown to aid re-growth of dopaminergic neurons associated with motor nerve function in the SN. Drug companies decided to go back to the drawing board on it because of severe, life threatening side effects in some of the patients. 60 minutes did a story on this back in 2005 on a particular person that had amazing success with the treatment.

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