Huntington’s disease is a disorder in which nerve cells in certain parts of the brain degenerate. This disorder is passed down through families due to a genetic defect on chromosome 4. This defect causes part of DNA called a CAG repeat to occur more times than it’s supposed to. The larger number of repeats in the DNA, the higher the chances of someone developing symptoms at an early age.
Huntington’s disease causes symptoms such as:
- Uncontrolled movements
- Dementia that worsens over time
Researchers have now demonstrated that skin cells can be converted to a specific type of brain cell called medium spiny neurons, which are most affected by Huntington’s disease. Their technique is unique due to their new process that bypasses the stem cell phase.
The reasearch involved adult human skin cells, which are more easily accessible. Using a patient’s own cells ensures that their immune system will not reject them.
In a skin cell, DNA instructions on how to be different types of cells are hidden. Exposure to two micronRNAs, called miR-9 and miR-124, alters how those instructions are packed away inside the cell. As soon as the genes important for becoming brain cells opened up, researchers started to tweak the chemical signals, exposing the cells to additional molecules called transcription factors. These molecules are present in the part of the brain where the medium spiny neurons are common. The skin cells were eventually converted into the brain cells after prolonged exposure to the transcription factors.
The cells were then injected into the brains of mice and were proven to look and behave the way native medium spiny neurons would.
Researchers are now taking skin cells from patients with Huntington’s disease and reprogramming them into the necessary brain cells. Plans to inject mice with a model of Huntington’s diseased with reprogrammed cells is underway.
Information compiled from Sciencedaily.com