I’m an MND researcher based at the Heart Research Institute in Sydney. I’m fairly new to MND, having come on board via a collaboration with Dr Paul Cox from the Institute for Ethnomedicine in Wyoming who is searching for an environmental trigger for sporadic MND.
My research focuses on the charging of non-protein amino acids by tRNA synthetases and their insertion into protein chains to make non-native proteins. We have extensive evidence showing that the pharmacotherapy (called levodopa) used to treat the neurodegenerative disorder Parkinson’s Disease can be mistaken by the protein synthesis machinery and inserted into proteins in the place of tyrosine. Evidence from cell culture shows this mis-incorporation generates proteins that aggregate, are autofluorescent, resist proteolysis, and induce cell death by apoptosis. We have also found elevated levels of proteins containing DOPA in the blood of PD patients taking levodopa.
We hypothesise that proteins such as these are associated with neurodegenerative pathologies, including MND, where genes involved in protein folding and degradation have been identified. Our hypothesis for a role for mis-incorporation of non-protein amino acids in pathology is not entirely novel. For example, an analogue of tryptophan has been linked to an autoimmune disorder and canavanine has been associated with SLE or lupus.
With respect to MND, we are exploring a role for an amino acid analogue (which is also a neurotoxin) which has been found in the brains of MND patients in sporadic MND. BMAA is a ubiquitous environmental toxin which is synthesised by blue green algae and is also a symbiot of cycad trees. It was first discovered when a dietary link was made between an increased incidence of an MND-like disorder (called ALS/PDC) in the indigenous people of Guam and their voracious appetite for fruit bats which had high concentrations of BMAA. Blue green algal blooms occur frequently in fresh and salt water and subsequently reports have surfaced that high levels of BMAA are found in the flesh of seafood, especially filter feeders such as mussels. Thus, the opportunity for human exposure is significant.
I will be attending the BMAA session “BEYOND GUAM: NEW ASPECTS OF THE BMAA HYPOTHESIS” from 08:30 – 10:30 and presenting a poster from 10:30 – 12:30 on Thursday December 1st during the Sydney symposium. Please come and say hi.
You can read more about the BMAA hypothesis and ALS/MND in my blog post “A tale of blue green algae, attacking birds, Hollywood and dementia”
Cheers Rachael A. Dunlop