There are resident proteins in cells whose job it is to make sure that junk proteins do not pile up. These proteins are called molecular chaperones, they can tidy up the cell by recognising and removing damaged proteins. There are many of these chaperones inside cells. It makes sense then that these chaperone proteins may be involved in MND since all forms of MND are associated with accumulations of proteins. Work coming out of Dr Julie Atkin's laboratory at the University of Melbourne suggests that a protein called PDI may be an important chaperone for mutant SOD1. Increasing the levels of PDI actually diminishes the amount of SOD1 accumulated in the cell and protects cells from mutant SOD1 toxicity. Interestingly, PDI is altered in sporadic MND patients as well as mutant SOD1 mice to a form that doesn't work as well at preventing the SOD1 pile up. The researchers also showed that small molecule drugs could be used to mimic PDI and provide similar effects. In addition, researchers from Yale, USA show that a drug called Nogo-A can increase the amount of PDI available and prolong the life of mutant SOD1 MND mice.
Source: International MND research update -December 2009, Dr Justin Yerbury for MNDRIA