A worm called Caenorhabditis elegans with 600 million years of evolution behind it holds the same sequence of miR-1 as humans and has been revealed as the secret to destroying toxic cells in Neurodegenerative diseases.
Associate Professor Roger Pocock from the Monash Biomedicine Discovery Institute and colleagues from the University of Cambridge led by Professor David Rubinsztein have homed in on a particular microRNA that is important for regulating protein aggregates in neurodegenerative diseases.
Protein aggregates are proteins that have amassed due to a malfunction in the process of ‘folding’ which determines their shape and are considered the hallmark of numerous human diseases.
miR-1 is found in low levels in patients with neurodegenerative diseases however the scientists identified a highly conserved mechanism in a particular worm and in humans that controls the removal of toxic protein aggregates.
Associate Professor Pocock said the sequence of miR-1 is 100 percent conserved; it’s the same sequence in the Caenorhabditis elegans worm as in humans even though they are separated by 600 million years of evolution. “We deleted miR-1 in the worm and looked at the effect in a preclinical model of Huntington’s and found that when you don’t have this microRNA there’s more aggregation,” Associate Professor Pocock said.
“This suggested miR-1 was important to remove Huntington’s aggregates.” The researchers then showed that miR-1 helped protect against toxic protein aggregates by controlling the expression of the TBC-7 protein in worms. This protein regulates the process of autophagy, the body's way of removing and recycling damaged cells and is crucial for clearing toxic proteins from cells. “When you don’t have miR-1, autophagy doesn’t work correctly and you have aggregation of these Huntington’s proteins in worms,” Associate Professor Pocock said. “Expressing more miR-1 removes Huntington’s aggregates in human cells." “It’s a novel pathway that can control these aggregation-prone proteins. As a potential means of alleviating neurodegenerative disease, it’s up there,” he said. Additional work by Associate Professor Pocock’s colleagues showed that when human cells are supplied with a molecule called interferon-b the miR-1 pathway is upregulated, revealing a way of manipulating it. The researchers have provisionally patented their findings and are in discussions with pharmaceutical companies about translating the research. They will further test it in preclinical models for Huntington’s and Parkinson’s disease. This research was supported by the Australian NHMRC and their findings have been published in eLIFE . Read the full paper in eLIFE titled Interferon-β-induced miR-1 alleviates toxic protein accumulation by controlling autophagy.