Scientists used X-ray microscopy to discover deposits of unusual metallic copper and magnetic iron within the brains of Alzheimer’s patients.
Did you know humans have enough iron in their body to form a 3-inch-long metal nail? Most of this iron is found in our blood, but it’s not the only metal present in the human body. Other metals such as copper and zinc are also present in blood and in trace amounts within the brain. These metals help maintain various physiological processes. However, copper and iron can also exist in the body in different oxidation states. The chemically reduced Copper and Iron can induce oxidative stress; thus, leading to cell death. Therefore, the body constantly regulates levels of these harmful forms of metals. Now, for the first time, researchers have discovered the harmful elemental forms of copper and iron in the brains of Alzheimer’s patients.
Alzheimer’s is a progressive neurodegenerative disorder that results from destruction of neurons and loss of brain function. Amyloid plaques and accumulation of tau proteins within the brain are the two main pathological features of Alzheimer’s disease. Moreover, previous research has shown that excessive iron and copper in the brain can further trigger the development of these amyloid plaques.
To investigate this link further, a team of researchers analyzed brain tissue donated by two Alzheimer’s patients. They used a form of X-ray microscopy (STXM) to analyze the amyloid plaques within the frontal and temporal lobe of the patients’ brains. Furthermore, the X-rays helped the researchers determine the size of the metal deposits, their shape, and the identity of the minerals.
What Does the Future Hold?
The results of the study are available in the journal Science Advances.
The investigation revealed traces of the elemental form of iron and copper within the amyloid plaques. Moreover, researchers discovered that the core of the plaques contained nanoparticles of both metals in the unoxidized states. The presence of the ionized metals suggests they may play a role in inflammation and causing cell damage and death.
Consequently, the authors of the study believe therapies that target these unusual forms of iron and copper can likely help reduce the oxidative stress burden in the brains of Alzheimer’s patients. However, the mechanism behind the formation of amyloid plaques and whether the deposits of copper and iron are also present in healthy individuals is still unclear. Hence, researchers call for further studies that investigate the link between Alzheimer’s and metal deposits.
James Everett et al, Biogenic metallic elements in the human brain?, Science Advances (2021). DOI: 10.1126/sciadv.abf6707
Liu JL, Fan YG, Yang ZS, Wang ZY, Guo C. Iron and Alzheimer’s Disease: From Pathogenesis to Therapeutic Implications. Front Neurosci. 2018;12:632. Published 2018 Sep 10. doi:10.3389/fnins.2018.00632