Defective Calcium Metabolism in Nerve Cells Contributes to Neurological Disorder
Spinocerebellar ataxia 3 (SCA3) is a rare condition in which the patient’s coordination, speech, and vision are impaired, and causes atrophy of the brain. This rare genetic disease is otherwise known as Machado-Joseph disease and is mostly seen in people with Portuguese heritage. SCA3 displays similar conditions as Huntington’s disease.
SCA3 and Huntington’s disease are caused by disturbed calcium signaling within nerve cells. This is due to repeating segments of DNA which affect the amino acid code, causing a repetition of units of glutamine in the mutated proteins. The more often the repeats occur, the earlier the disease starts to affect the patient.
Researchers have found that in the presence of the mutated protein ataxin-3, calcium is released from the endoplasmic reticulum. In normal ataxin-3, stored Ca2+ is not released.
Such high levels of calcium in a cell are toxic and lead to impaired motor function. Researchers found this to be a similar case in genetically engineered knock out mice with over expressed human ataxin-3 protein. The mutant mice displayed signs of brain deterioration in the same regions of the brain as patients with SCA3 and Huntington’s.
Researchers then gave these knock out mice Dantrolene, an emergency treatment for humans if a patient reacts to anesthesia, to determine if it would block the excessive amount of calcium release in skeletal muscle cells. Dantrolene is only allowed to be used once due to the side effects. They found this treatment to lessen the symptoms of the over expressed ataxin-3 protein.
The conclusion of this research was not that Dantrolene was the answer to curing SCA3 and Huntington’s due to its side effects. They concluded that they could make a more precise drug that would block Ca2+ release from the ER of skeletal muscle cells, improve the coordination skills and slow brain atrophy of patients suffering from SCA3 and Huntington’s disease without causing the side effect of Dantrolene. This research has also been used to study other neurodegenerative diseases.
I found this article to be interesting enough to share because it pertains to the material about skeletal muscles we just covered in class. This article discusses how the amount of calcium in cells determines the functions of cells. This research is important to our medical society because it allows us to better understand what causes some neurological diseases.
http://www.news-medical.net/?id=43480
SCA3 and Huntington’s disease are caused by disturbed calcium signaling within nerve cells. This is due to repeating segments of DNA which affect the amino acid code, causing a repetition of units of glutamine in the mutated proteins. The more often the repeats occur, the earlier the disease starts to affect the patient.
Researchers have found that in the presence of the mutated protein ataxin-3, calcium is released from the endoplasmic reticulum. In normal ataxin-3, stored Ca2+ is not released.
Such high levels of calcium in a cell are toxic and lead to impaired motor function. Researchers found this to be a similar case in genetically engineered knock out mice with over expressed human ataxin-3 protein. The mutant mice displayed signs of brain deterioration in the same regions of the brain as patients with SCA3 and Huntington’s.
Researchers then gave these knock out mice Dantrolene, an emergency treatment for humans if a patient reacts to anesthesia, to determine if it would block the excessive amount of calcium release in skeletal muscle cells. Dantrolene is only allowed to be used once due to the side effects. They found this treatment to lessen the symptoms of the over expressed ataxin-3 protein.
The conclusion of this research was not that Dantrolene was the answer to curing SCA3 and Huntington’s due to its side effects. They concluded that they could make a more precise drug that would block Ca2+ release from the ER of skeletal muscle cells, improve the coordination skills and slow brain atrophy of patients suffering from SCA3 and Huntington’s disease without causing the side effect of Dantrolene. This research has also been used to study other neurodegenerative diseases.
I found this article to be interesting enough to share because it pertains to the material about skeletal muscles we just covered in class. This article discusses how the amount of calcium in cells determines the functions of cells. This research is important to our medical society because it allows us to better understand what causes some neurological diseases.
http://www.news-medical.net/?id=43480
posted by BrittanyReinemund at 12:29 PM
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