Mouse Study Explores Underlying Cause of Motor Neuron Degeneration in SBMA

CHMP7 has shown up twice recently in research on SBMA. The previous article can be found here:

Gene expression analysis reveals early dysregulation of disease pathways and links Chmp7 to pathogenesis of spinal and bulbar muscular atrophy

SMA News published a well written article and excerpts can be found below and the entire article can be read at this link" 

Mouse Study Explores Underlying Cause of Motor Neuron Degeneration in SBMA

"...Results showed that 178 genes were upregulated (overly active), while 287 were downregulated (under-activated) in motor neurons from SBMA mice compared to healthy animals, indicating that transcriptional dysregulation in SBMA starts at an early stage of development.

One of the genes that was donwregulated in motor neurons from animals with SBMA was Chmp7 (Charged Multivesicular Body Protein 7). Interestingly, the expression levels of this gene also were affected in motor neurons from the spinal cord and lower legs of adult SBMA mice before the onset of symptoms. (Of note, gene expression is the process by which information in a gene is synthesized to create a working product, like a protein.)

Similar alterations in the expression levels of CHMP7 (the equivalent gene of Chmp7 in humans) also were found in motor neurons’ precursors derived from SBMA patients’ induced pluripotent stem cells (iPSCs), suggesting that Chmp7 may play an important role in SBMA development. iPSCs are fully matured cells that are reprogrammed back to a stem cell state, where they are able to grow into any type of cell.

Moreover, the research team discovered that other genes involved in multiple signaling cascades essential for cellular function, such as the tumor suppressor (p53), DNA repair and energy metabolism, also were dysregulated in motor neurons from SBMA animals.

In addition, scientists observed that SBMA motor neurons showed signs of mitochondria (the cell compartments responsible for the production of energy) dysfunction and DNA damage, possibly caused by transcriptional dysregulation of genes involved in energy metabolism and/or DNA repair.

“Taken together, these findings indicate that an interplay of multiple pathways contribute to the disease pathogenesis [development] of SBMA. Significantly, the dysregulated genes and pathways, and in particular Chmp7/CHMP7 identified by our transcriptomic profiling may serve as candidate druggable molecular targets for therapy development in SBMA,” the researchers concluded."