Using stem cells, researchers discern patterns to this puzzling disorder
You may have heard that one of the factors that makes autism research so complicated is that the disease is considerably heterogeneous. In fact, it is argued that the plural "autisms" is a more accurate term, as different diseases with different bases are actually grouped together under the "autism" umbrella. In fact, many patients with autism have no implicated genes in common.
But perhaps there really is a shared theme behind the dysregulation. Researchers acquired skin cells from four adolescent boys with autism spectrum disorder (ASD), as well as their fathers, who did not have ASD. Then they converted these cells to induced pluripotent stem cells (iPS cells), embryonic-like cells that can be ushered along a certain developmental course in the lab. The group coaxed the iPS cells to form cellular aggregates with similar features to the telencephalon, the embryonic structure from which the cerebrum develops.
The scientists found significant differences between the structures derived from the donors with ASD and those from controls. The ASD organoid cells proliferated faster at the early stages of development. But not all neurons were behaving this way -- it was the GABAergic, inhibitory, neurons that were increasing. The researchers also discovered that one of the consistently unregulated genes was FoxG1, a transcription factor that plays a critical role in telencephalon development. Further research may reveal exactly how these changes affect the growing structure of the brain.
Skin cells also came in handy for another research project. Scientists obtained such cells from people with a type of autism caused by Timothy syndrome. As in the other study, the cells were "reverted" to iPS cells; then they were directed to form neurons of the cortex. Comparing the product with controls, the team noticed disruption of electrical signaling, loss of long-distance connections, and elevated levels of norepinephrine and dopamine. Intriguingly, a drug, roscovitine, reverses this overproduction. But is roscovitine really effective, not to mention safe? We will have to stay tuned.
We at HemaCare invite stem cell researchers to consider our offering of stem cells such as CD34+ cells and mesenchymal stem cells. We also supply stable primary cells (PMBCs), which can be induced to generate iPS cells.
1. Mariani J et al. FOXG1-dependent dysregulation of GABA/glutamate neuron differentiation in autism spectrum disorders. 2015. Cell 162(2):375-390.
3. Yazawa M and Dolmetsch RE. Modeling Timothy syndrome with iPS cells. 2013. J Cardiovasc Transl Res. 6(1):1-9.