The Role of Zinc and Copper in Autism Spectrum Disorders

Acta Neurobiol Exp 2013 2Children with Autism spectrum disorders (ASDs) appear to be at risk for zinc (Zn) deficiency, copper (Cu) toxicity, have often low Zn/Cu ratio, and often disturbed metallothionein (MT) system functioning. The evidence presented in this paper suggests that providing Zn to autistic children may be an important component of a treatment protocol, especially in children with Zn deficiency. It is important to monitor and follow the values for both Cu and Zn together during Zn therapy, because these two trace elements are both antagonists in function, and essential for living cells. 

The review article by Geir Bjørklund is published in Acta Neurobiologiae Experimentalis (2013; 73 (2): 225–236). This peer-reviewed journal is published by Nencki Institute of Experimental Biology in Warsaw, Poland.

 

Geir Bjørklund

The role of zinc and copper in autism spectrum disorders

Acta Neurobiol Exp (Wars) 2013; 73 (2): 225-236 

 

ABSTRACT

Autism spectrum disorders (ASDs) are a group of developmental disabilities that can cause significant social, communication and behavioral challenges. Several studies have suggested a disturbance in the copper (Cu) and zinc (Zn) metabolism in ASDs. Zinc deficiency, excess Cu levels, and low Zn/Cu ratio are common in children diagnosed with an ASD. The literature also suggests that mercury accumulation may occur as a cause or consequence of metallothionein (MT) dysfunction in children diagnosed with an ASD, which may be one of the causes of Zn deficiency. MTs are proteins with important functions in metal metabolism and protection. Zinc and Cu bind to and participate in the control of the synthesis of MT proteins. Studies indicate that the GABAergic system may be involved in ASDs, and that Zn and Cu may play a role in this system.

 

Antioxidant may disrupt Alzheimer’s disease process

According to new study published in the Journal of Alzheimer’s Disease

Alzheimer’s disease (AD) is now the sixth leading cause of death among Americans, affecting nearly 1 in 8 people over the age of 65. There is currently no treatment that alters the course of this disease. However, an increasing amount of evidence suggests that changes in the way the body handles iron and other metals like copper and zinc may start years before the onset of AD symptoms. A new study shows that reducing iron levels in blood plasma may protect the brain from changes related to AD.

In the current study a group of investigators from led by Dr. Othman Ghribi, PhD, Associate Professor, Department of Pharmacology, Physiology, and Therapeutics, University of North Dakota School of Medicine and Health Sciences, rabbits were fed a high-cholesterol diet which caused them to accumulate plaques of a small protein called beta-amyloid (Aβ). These plaques are toxic to neurons and central to the development of Alzheimer’s disease. The rabbits also developed changes in tau protein, which is part of the skeleton of neurons. When this protein becomes heavily phosphorylated, the ability of neurons to conduct electrical signals is disrupted. Following treatment with a drug called deferiprone (an iron chelator), the iron level in the rabbits’ blood plasma was reduced and the levels of both beta-amyloid and phosphorylated tau in the brain were returned to normal levels.

Another degenerative process in AD involves the production of reactive oxygen species (ROS) that can damage neurons in the brain. Deferiprone is also thought to suppress this reactive oxygen damage caused by free iron in the bloodstream, however in this study there was no difference in reactive oxygen species in the treated group. It appears that iron in the AD brain is located in the wrong places – in particular it accumulates to very high levels in the cores of beta-amyloid plaques and is very reactive in this setting.

According to Dr. Ghribi, “Our data show that treatment with the iron chelator deferiprone opposes several pathological events induced by a cholesterol-enriched diet…Deferiprone reduced the generation of Aβ and lowered levels of tau phosphorylation.” While there was no effect on ROS levels, he comments that “It is possible that a higher dose of deferiprone, or combination therapy of deferiprone together with an antioxidant to prevent ROS generation would more-fully protect against the deleterious effects of cholesterol-enriched diet that are relevant to AD pathology.”

Noted expert on metals metabolism research on AD Ashley Bush, MD, PhD, Mental Health Research Institute, Melbourne, Australia, adds that “this research highlights the role of metal ions as key modulators for the toxic interactions of risk factors for Alzheimer’s disease, in this case cholesterol. Drugs targeting these metal interactions hold promise as disease-modifying agents.”

 

Reference

Prasanthi JR, Schrag M, Dasari B, Marwarha G, Kirsch WM, Ghribi O. Deferiprone Reduces Amyloid-β and Tau Phosphorylation Levels but not Reactive Oxygen Species Generation in Hippocampus of Rabbits Fed a Cholesterol-Enriched Diet. J Alzheimers Dis. 2012 Mar 9. [Epub ahead of print]

 

Benefits of Copper

Find out how copper helps your body.

Benefits of Copper. Videogram. Colorado Springs, CO: Mineralife LLC, 2011.

Copper Folds Protein Into Precursors Of Parkinson’s Plaques

Researchers at North Carolina State University have figured out how copper induces misfolding in the protein associated with Parkinson’s disease, leading to creation of the fibrillar plaques which characterize the disease. This finding has implications for both the study of Parkinson’s progression, as well as for future treatments.

The protein in question, alpha-synuclein, is the major component of fibrillar plaques found in Parkinson’s patients. Researchers had already discovered that certain metals, including copper, could increase the rate of misfolding by binding with the protein, but were unsure of the mechanism by which this binding took place.

“We knew that the copper was interacting with a certain section of the protein, but we didn’t have a model for what was happening on the atomic level,” says Frisco Rose, Ph.D. candidate in physics and lead author of the paper describing the research. “Think of a huge swing set, with kids all swinging and holding hands – that’s the protein. Copper is a kid who wants a swing. There are a number of ways that copper could grab a swing, or bind to the protein, and each of those ways would affect all of the other kids on the swing set differently. We wanted to find the specific binding process that leads to misfolding.”

Rose and NC State colleagues Dr. Miroslav Hodak, research assistant professor of physics, and Dr. Jerzy Bernholc, Drexel Professor of Physics and Director of the Center for High Performance Simulation, developed a series of computer simulations designed to ferret out the most likely binding scenario.

According to Hodak, “We simulated the interactions of hundreds of thousands of atoms, which required multiple hundred thousand CPU-hour runs to study the onset of misfolding and the dynamics of the partially misfolded structures.”

The number of calculations was so large that Hodak and Bernholc had to devise a new method to make it possible for a computer to process them. Only supercomputers like Jaguar, Oak Ridge National Laboratory’s most powerful supercomputer – the most powerful in the United States, in fact – were up to the task. But the simulations finally revealed the binding configuration most likely to result in misfolding.

Their results appeared in the June 14 edition of Nature Scientific Reports.

The researchers hope that their finding will advance our understanding of Parkinson’s, one of the most common – and devastating – neurological diseases. “Understanding the molecular mechanism of Parkinson’s disease should help researchers in developing drugs that treat the disease rather than merely alleviate symptoms,” Bernholc says.
Reference

Rose F, Hodak M, Bernholc J. Mechanism of copper(II)-induced misfolding of Parkinson’s disease protein. Scientific Reports 2011; 1, doi:10.1038/srep00011.