In a new development in the Alzheimer's world, scientists have found tiny deposits of elemental, uncharged iron, and copper in human brains. An international team of researchers discovered the microscopic metals in postmortem brain samples from two Alzheimer's patients. Metal ions are essential components of many enzymes that catalyze chemical reactions in cells. These positive ions can strip the electrons from other molecules, oxidizing these molecules.
The deposits of copper and iron that the scientists identified in the brain tissue of people with Alzheimer's were however, in their elemental, uncharged form. These are highly reactive metal atoms that, under normal circumstances, would rapidly undergo oxidation to form more chemically stable ions.
Researchers found the metals within beta-amyloid plaques, which are the clumps of protein that are a hallmark of Alzheimer's disease. Why is this important? The tiny deposits of elemental iron that the team found in the new study were magnetic, in theory, doctors could use them for diagnosis or as a marker of disease progression.
Scientists from Keele University and the University of Warwick in the UK and those at the University of Texas in the US collaborated for the study. The research has been published in the medical journal Science Advances. The team used exceptionally powerful X-rays from the UK's national synchrotron Diamond Light Source and the Advanced Light Source in California to image the brain tissue.
Co-author Joanna Collingwood, Ph.D., says, “This is a fascinating and unexpected discovery, enabled by the sensitivity and precision of the synchrotron techniques we have used to study these human-brain-derived samples. We know that certain living systems can produce elemental forms of metals, so it will be important to discover if these arise from equivalent but previously undiscovered pathways in humans, or if the metallic forms arise as a direct consequence of disease.”
Co-author Neil Telling, Ph.D., professor of biomedical nanophysics at Keele University said, “It is entirely feasible that beta-amyloid prevents the elemental iron and copper from oxidizing. These elemental phases are extremely reactive to oxygen, so for us to be capable of measuring them using X-ray microscopy must mean their oxidation state has been stabilized in some capacity.”
He added, “This line of research could ultimately lead to new treatments that target metals, as well as the amyloid proteins currently under consideration. The existence of tiny magnetic iron particles within plaques could also help with diagnosis and to monitor disease progression, as they could, in principle. be detected by MRI scanners.”
