New Delhi, Feb. 9: In pencil-sized plastic vials filled with iron and proteins, biochemist Sandeep Verma has caught a glimpse of how rust might get inside the human brain.

Under a microscope, the contents of the vial reveal worm-like fibres of a protein dotted with deposits of rusted iron — a hint of what might happen in the body whose housekeeping has gone awry.

Verma’s experiments at IIT Kanpur show how a molecule-turned-rogue may cause iron rust to deposit in the brain and lead to incurable neurological disorders such as Parkinson’s disease and Alzheimer’s disease.

Several studies had earlier hinted that iron deposits in the brain might lead to some forms of these two ailments. Verma’s research provides the first clues how that might happen, though his findings are yet to be confirmed through studies on real brain tissues.

Both Parkinson’s and Alzheimer’s are age-associated degenerative brain disorders. Parkinson’s patients suffer from movement and gait disorders; Alzheimer’s symptoms include devastating memory loss and dementia-like conditions.

“This is possibly the first insight into how rust can enter the human brain,” said Verma, a bio-organic chemist at IIT Kanpur, who worked jointly with Peter Sadler, senior chemist at Britain’s University of Warwick, to study the fate of iron in the body. The researchers have just published their results in the journal Angewandte Chemie.

Iron is carried out of the bloodstream by a molecule called transferrin. “This molecule curls around the iron and seals it to prevent it from interacting with anything else until it reaches where it is needed in the body,” Verma said.

The researchers found that if transferrin is left to dry, this molecular courier assembles itself into long, worm-shaped fibres and the iron within settles along the length of the fibres in dotted patterns.

The scientists call it mineralisation, a process that allows the iron to take up oxygen and rust. In the human body, there is unlikely to be any such drying up but the researchers say it is possible that ageing may lead to similar changes.

“This process might expose the iron dangerously and allow it to interact with surrounding tissues in ways that could cause cell damage,” Verma said. “But the true test of this theory would be to actually examine diseased brain tissues for iron rust.”

These laboratory experiments, he said, should prompt medical researchers to look out for such deposits of rusted iron in diseased brain tissues.

Neuroscientists say there is indirect yet strong evidence to suggest that iron deposits in the brain may play a role in Parkinson’s. The substantia nigra — the part of the brain affected in this disorder — has excess iron, said Vijayalakshmi Ravindranath, director of the National Brain Research Centre in Manesar, Haryana.

Studies on genetically engineered mice suggest that mopping up excess iron from the brain may protect them from Parkinson’s, Ravindranath said. “It is possible that the iron overload leads to a harmful biological process called oxidative stress that destroys cells in the subtantia nigra.”

But despite numerous studies hinting at a similar connection between iron overload in the brain and Alzheimer’s, a cause-effect relationship has not been established, Ravindranath added.

IRON GRIP

A rogue molecule in the body may cause iron rust to accumulate in the brain and lead to incurable disorders such as Parkinson’s, Alzheimer’s and Huntington’s diseases, an Indo-UK research team has suggested.

The findings — based on test-tube experiments and yet to be confirmed through studies on brain tissues — suggest that tiny fibres coated with rust may get deposited in the brain when something goes wrong with a protein that ferries iron across the body