- Parkinson's disease is a
degenerative disorder of the brain and has no cure at present.
- Genetic mutation causing low levels
of expression of parkin protein is known to cause Parkinson's disease.
- Study identifies stress hormone
cortisol as the
cause of the over-expression
of parkin protein and prevent as well as be a possible cure for
Cortisol, a natural hormone present in
the body could be potentially used for treating and preventing Parkinson's
disease, a debilitating degenerative brain disorder, according to a study conducted by
scientists at the DGIST (Daegu Gyeonbuk Institute of Science and Technology) in
For the Study
‘Since cortisol is a physiological hormone, maintaining its optimal levels could be a potential preventive measure and treatment option for Parkinsonís disease.’
Until now there is no cure in sight for
. It is known that a mutation causing decreased expression of
parkin protein induces PD
by causing death of dopaminergic neurons in the
The research team performed assays to evaluate gene expression, using a wide range of chemicals to
identify substances that could increase parkin expression.
The team hoped that their research would
succeed in finding a potential cure for this debilitating condition.
and Findings of the Study
levels of parkin expression, the team of scientists performed a luciferase
assay employing various chemicals
in cell and animal model based
experiments. Among the various chemicals tested that were found to increase the
levels of parkin protein expression, the following results were observed.
of Parkin Gene and Protein in Parkinsonism
- Hydrocortisone showed the most
favorable profile in terms of increasing parkin expression, and protecting
the cell from oxidative damage and stress.
- Hydrocortisone mediated expression
of parkin via the CREB (cAMP response element-binding protein) pathway,
which is a cellular transcription factor that regulates gene expression.
- Hydrocortisone was able to prevent
6-hydroxy dopamine (a toxin) induced neuronal loss by increasing parkin
expression, thus demonstrating its neuroprotective effect.
- Blocking the glucorticoid receptor
abolished the favorable response of inducing parkin expression, suggesting
that the physiological
cortisol signaling pathway has a role to play in parkin expression.
The PRKN gene provides instructions for
the expression of a protein called parkin. This protein parkin is critical to the removal of damaged organelles, unwanted and toxic
cellular accumulations by tagging them to molecules termed ubiquitin. The
ubiquitin then disposes these cellular toxic accumulations via specialized
structures called proteasomes.
Thus the parkin-ubiquitin-proteasome pathway is very important in disposing
unwanted and toxic substances and preventing oxidative stress induced damage
of the neurons in the
When this cellular scavenging system goes
awry, there is damage to and destruction of the dopaminergic neurons in the
brain leading to Parkinson's disease.
PD is a neurodegenerative disease usually
affecting the elderly characterized by tremor, postural and movement
difficulties and is a debilitating condition.
of the Study
The findings of the study suggest that PD patients, especially those with an
impaired hypothalamic-pituitary (HPA)
resulting in low serum cortisol levels, would benefit from therapeutic
supplementation of hydrocortisone.
More research may be required before
establishing the safety and efficacy of hydrocortisone in PD, but initial
findings appear promising.
The senior researcher Yoon-Il Lee stated
"The significance of this study is that it has identified that the
expression of parkin protein induced by a moderate level of stress hormone
cortisol could be an important factor in maintaining the viability of
dopaminergic neurons. We will continue to conduct follow-up studies such as
clinical studies so that the Parkinson's disease will be curable in the
- Parkin structure and function - (https://www.ncbi.nlm.nih.gov/pubmed/25712550)
- Dual Luciferase Assay System for Rapid Assessment of Gene Expression in Saccharomyces cerevisiae - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1214206/)
- PRKN gene - (https://ghr.nlm.nih.gov/gene/PRKN)