Using tissue biopsies from the thin lining of the nasal passages from people with mental disorders, Johns Hopkins researchers are collecting genetically unaltered stem cells to better study the cause of diseases like schizophrenia and bipolar disorder.
Akira Sawa, M.D., Ph.D., professor of psychiatry and director of the Schizophrenia Center at the Johns Hopkins University School of Medicine, and his colleagues have found a way to separate out the stem cells from the nasal passages and coax them into neurons in a procedure they say will provide an alternative patient cell source that leaves the chemical marks on genomes' DNA sequences intact.
The standard approach for obtaining patient cells to study diseases uses induced pluripotent stem (iPS) cells — cells taken from the blood or a skin biopsy that are converted to a stem cell state by adding extra DNA. The stem cells are then converted to a cell type of choice. According to the researchers, unlike iPS cells, those garnered from nasal biopsies do not have changes to their epigenetics features — the heritable information in the DNA other than the DNA sequence itself, like the presence of extra chemical modifications on the DNA letters.
Epigenetics may play a crucial role in many complex diseases where single genetic causes or specific groups of genes don't appear to contribute to disease, like in heart disease, autism or schizophrenia.
"If we only use iPS cells to study these types of diseases, we might miss the key epigenetic causes," says Sawa. "Both types of cells have clear advantages and disadvantages that if studied together can provide a complementary approach to better understanding mental disorders."
He noted that the nasal biopsy cells are faster to culture, but these cells can't be converted to as many different types of neurons as iPS cells. Using these nasal biopsy cells, the Sawa lab hopes to uncover molecular, especially epigenetic, causes for mental disorders, which would allow for the development of new therapeutics.
Talk/Program#: 521.05, Room 395, Tuesday, Oct. 16, 2012, 9-9:15 a.m. CST
Authors: C.-Y. Lin, Y. Horiuchi, K. Ishizuka, A. Sawa