Tag: creatine

Getting Vital Creatine into the Brain is a Weighty Problem

Photo by Jonathan Borba on Unsplash

Creatine is popularly known as a muscle-building supplement, but its influence on human muscle function can be a matter of life or death. But getting it to one particular organ that needs it – the brain – is challenging.

“Creatine is very crucial for energy-consuming cells in skeletal muscle throughout the body, but also in the brain and in the heart,” said Chin-Yi Chen, a research scientist at Virginia Tech’s Fralin Biomedical Research Institute at VTC.

Chen is part of a research team working to develop a technique that uses focused ultrasound to deliver creatine directly to the brain. The work, being conducted in the lab of Fralin Biomedical Research Institute Assistant Professor Cheng-Chia “Fred” Wu, will be supported by a $30 000 grant from the Association for Creatine Deficiencies.

Creatine plays a vital role in the brain, where it interacts with phosphoric acid to help create the key energy molecule adenosine triphosphate (ATP). In addition to its role in energy production, creatine also influences neurotransmitter systems.

For example, creatine influences the brain’s major inhibitory pathways that use the neurotransmitter gamma-aminobutyric acid (GABA), which limits neuronal excitability in the central nervous system. It may play a role in a variety of functions, including seizure control, learning, memory, and brain development.

A growing body of research suggests that creatine may itself function as a neurotransmitter, as it is delivered to neurons from glial cells in the brain and can influence signalling processes between other neurons. While creatine deficiency disorders can weaken the skeletal muscle and the heart, they can also severely affect the brain. Many patients see increased muscle mass and body weight with creatine supplements, but they often continue to face neurodevelopmental challenges that can hinder their ability to speak, read, or write.

This is largely caused by the brain’s protective blood-brain barrier preventing creatine entry.

Wu studies therapeutic focused ultrasound, which precisely directs sound waves to temporarily accessed areas of the brain. The process allows drugs to reach diseased tissue without harming surrounding healthy cells. While Wu is investigating this method as a potential treatment for paediatric brain cancer, he also sees potential in applying it to creatine deficiency.

“Through the partnership between Virginia Tech and Children’s National Hospital, I was able to present our work in focused ultrasound at the Children’s National Research & Innovation Campus,” Wu said. “There, I met Dr Seth Berger, a medical geneticist, who introduced me to creatine transporter deficiency. Together, we saw the promise that focused ultrasound had to offer.”

The Focused Ultrasound Foundation has recognised Virginia Tech and Children’s National as Centers of Excellence. Wu said the two organisations bring together clinical specialists, trial experts, and research scientists who can design experiments that could inform future clinical trials.

“It was a moment that made me really excited – that I had found a lab where I could move from basic research to something that could help patients,” Chen said. “When Fred asked me, ‘Are you interested in this project?’ I said, ‘Yes, of course.’”

Because creatine deficiencies can impair brain development, the early stages of Chen’s project will concentrate on using focused ultrasound to deliver creatine across the blood-brain barrier. Chen hopes the technique will restore normal brain mass in models of creatine deficiency.

Source: Virginia Tech

How Muscle Energy Production is Impaired in Type 2 Diabetes

Mitochondria (red) are organelles found in most cells. They generate a cell’s chemical energy. Credit: NICHD/U. Manor

A new study from Karolinska Institutet, published in Science Translational Medicine, shows that people with type 2 diabetes have lower levels of the protein that breaks down and converts creatine in the muscles. This leads to impaired function of the mitochondria, the ‘powerhouses’ of the cell.

Creatine is a popular supplement for improving exercise performance as it can make muscles work harder and longer before they become fatigued. Previous studies however showed a possible link between high blood creatine levels and increased type 2 diabetes risk. This has raised questions about whether creatine supplementation may contribute to that risk.

New research based on studies in both humans and mice shows that people with type 2 diabetes have lower protein levels in their muscles that metabolises and converts creatine – a protein called creatine kinase. 

“This reduced protein level leads to impaired creatine metabolism in the muscle. This may explain why people with type 2 diabetes accumulate creatine in their blood,” says principal investigator Anna Krook, Professor at the Department of Physiology and Pharmacology at Karolinska Institutet.

Scientists don’t know exactly what high creatine levels in the blood mean for the body, but it is known that it does have an effect outside the cells. 

“The findings indicate that impaired creatine metabolism is a consequence of type 2 diabetes, rather than a cause of the disease,” says Anna Krook. 

Impairs mitochondrial function

The study also shows that low levels of creatine kinase are not only linked to higher creatine levels in the blood, but also impair the function of mitochondria in the muscle. Mitochondria, which convert nutrients into energy, function less well in muscle cells with reduced creatine kinase, leading to both lower energy production and increased cell stress.

“This is quite consistent with the fact that people with type 2 diabetes have poorer energy metabolism. In the future, one possibility could be to regulate creatine kinase as part of the treatment of metabolic diseases such as obesity and diabetes,” says Anna Krook.

An unexpected finding of the study was that changes in creatine kinase levels affected the appearance of mitochondria and also their ability to produce energy, regardless of the amount of creatine available. 

“This suggests that although the main role of creatine kinase is to process creatine, it affects mitochondrial function in other ways,” explains David Rizo-Roca, the study’s first author.

“Our next step is to find the molecular mechanisms behind these effects,” he says. 

Source: Karolinska Institutet