Scientists Discover New Protein Related to Down Syndrome

New Protein Related to Down Syndrome

Researchers from the University of Michigan, in the United States, reveal a new aspect related to Down’s syndrome. They managed to observe the impact that up-regulation and down-regulation of a gene related to the syndrome has on the nervous system of the patients. Their discovery could lead to progress in future therapeutic approaches. The neurons of a healthy person begin to develop and expand their protrusions immediately after birth. During this period, each neuron produces high amounts of a protein, known as Dscam (Down syndrome cell-adhesion molecule), which is regulated by the gene. After the growth period of the neurons, the level of protein drops dramatically in healthy patients. However, in patients suffering from Down’s syndrome, with symptoms such as epilepsy, the protein maintains its high levels. The researchers weren’t yet able to discover the effect that the high level of protein has on the development of neurons.

Down Syndrome

Professor Bing Ye, the lead author of the study, discovered that the neuron growth of the Drosophila fly is in direct connection to the amount of Dscam protein present in the cell. Higher levels of Dscam meant that the protrusions of the neuron extended further before forming connections with the other nervous cells, when compared to the protrusions of neurons with lower levels of Dscam protein. Professor Ye and his team also report the discovery of two separate molecular pathways that converge and regulate the levels of Dscam. The first pathway, consisting of the DLK (dual leucine zipper kinase), is responsible for the up-regulation of Dscam proteins. The second pathway, consisting of a FMRP (fragile X mental retardation protein), down-regulates the synthesis of Dscam proteins. Professor Ye explains that these genes are common for humans and Drosophila flies, and so, these pathways could also provide a new therapeutic target against Down’s syndrome.

Precedent studies have already discovered that there are multiple genes involved in the onset and evolution of Down’s syndrome. However, the mechanisms through which the genetic defects produce the disease are still not completely understood. Professor Ye affirms that their new discovery is important because of its role in the development of nervous cells. The researchers are already planning their future studies. Their first attempt will be to see if high levels of Dscam proteins in the nervous cells of laboratory mice has an effect on their behavior and nervous system. Recent estimates show that Down’s syndrome affects 1 in 830 newborns around the world.