Calcium Imbalance in the Mitochondria Linked to Alzheimer's Disease

822a4983-b3b9-4b6d-83e5-bd76b808fe62articleimage.jpg

16 Feb 2017 --- Calcium in the mitochondria may be one of the keys to understanding and treating Alzheimer's disease and dementia, according to a study from the Center for Translational Medicine at Temple University.

The researchers have identified how an imbalance of calcium ions in the mitochondria may contribute to cell death and, specifically, neurodegeneration in brain cells during Alzheimer's and dementia.

The findings could eventually point to new therapies for preventing or delaying these diseases.

The mitochondria of a neuron, calcium ions are thought to control the production of energy needed for the brain to function. But if there's too much calcium, as has been suggested to occur in Alzheimer’s disease, it can cause cells to die.

Previous studies have suggested that an imbalance of calcium in neurons might play an important role in the onset of Alzheimer's disease. But how this was linked with mitochondrial dysfunction and neurodegeneration was unclear.

The new research led by Pooja Jadiya, a postdoctoral fellow working in John Elrod's lab at Temple University, found that one possible mechanism of Alzheimer’s disease involves the removal of calcium from mitochondria. Calcium ions exit a neuron's mitochondria with the help of a transporter protein called the mitochondrial sodium/calcium exchanger.

The researchers studied samples of human brains taken from Alzheimer's patients. In these diseased tissues, they found that the levels of this exchanger were so low, they were barely detectable.

Such low levels caused calcium to build up in the diseased mitochondria. They hypothesized that this may trigger excessive production of reactive oxygen species, molecules known to wreak havoc in the cell and contribute to neurodegeneration.

The researchers also found that the reduced activity of this exchanger was associated with impaired energy production and increased cell death, which may contribute to the neurodegeneration that causes Alzheimer's disease.

When the researchers studied mice that were genetically altered to develop Alzheimer's, they found that before the onset of the disease, the gene that encodes the exchanger protein was much less active -- suggesting that a drop in the gene's expression might contribute to disease progression.

To probe this mechanism further, the researchers studied this gene in an Alzheimer’s cell culture model. Like the mice, the cells were genetically altered to exhibit the cellular symptoms of Alzheimer's. When the researchers genetically boosted the levels of the mitochondrial sodium-calcium exchanger, the diseased cells recovered and were nearly identical to the control healthy cells. Production of ATP increased, reactive oxygen species decreased, and fewer cells died.

"No one's ever looked at this before using these model systems," Elrod said. "It’s possible that alterations in mitochondrial calcium exchange may be driving the disease process."

The researchers, including collaborators from the lab of Domenico Praticò, also at Temple University, are now trying to see if they can reverse the development of Alzheimer's in mutant mouse models by ramping up the gene that encodes the sodium-calcium exchanger. If they can, then this mechanism could eventually be the basis for new treatments aimed at boosting the function of the mitochondrial sodium-calcium exchanger, using approaches like new drugs or gene therapy.

"Our hope is that if we can change either the expression level or the activity of this exchanger, it could be a viable therapy to use early on to perhaps impede Alzheimer's disease development -- that's the home run," Elrod said. "We're not even close to that, but that would be the idea."

To contact our editorial team please email us at editorial@cnsmedia.com

Related Articles

Nutrition & Health News

“Why overcomplicate nutrition?” Huel co-founder and CEO on market potential of complete meal replacements

22 Jun 2018 --- “People overcomplicate nutrition; it’s not rocket science. For the lay consumer, getting your nutrition right needn’t be that hard.” This is according to nutritionist James Collier, co-founder of Huel, a meal replacement brand currently seeing huge growth in Europe and the US. Launched three years ago, the company is reportedly one the fastest growing companies in the UK, with revenues of over £14 million (US$18.6 million) in 2017. 

Nutrition & Health News

Personalized nutrition: Mindful and aware consumers drive market opportunity

19 Jun 2018 --- Personalized nutrition has taken its place as a key industry topic, spurring the launch of a number of innovative start-ups using cutting-edge technologies to offer precise nutrition advice to consumers. This growing industry space will be the topic of discussion at the Personalized Nutrition Innovation Summit, which is taking place in San Francisco on June 26-27.

Nutrition & Health News

Low maternal selenium may have consequences for mother's heart health in later life: Cypress Systems

18 Jun 2018 --- By increasing their risk of preeclampsia, mothers with low selenium levels may also be at increased risk for heart disease, stroke and high blood pressure later in life, a Cypress Systems executive summary suggests. The summary calls for higher levels of supplementation of high selenium yeast to combat heart health threats.

Nutrition & Health News

First time finding: Allergy to red meat may be a factor in heart disease

18 Jun 2018 --- A team of researchers says it has linked sensitivity to an allergen in red meat to the buildup of plaque in the arteries of the heart. While high saturated fat levels in red meat have long been known to contribute to heart disease for people in general, the new finding suggests that a subgroup of the population may be at heightened risk for a different reason – a food allergen. The study, which is supported by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health and appears in Arteriosclerosis, Thrombosis, and Vascular Biology.

Nutrition & Health News

“Dietary fibers” classification: US FDA green lights eight ingredients

15 Jun 2018 --- The US Food and Drug Administration (FDA) has issued guidance which identifies eight specific fibers that can be classified as “dietary fibers” on the upcoming Nutrition Facts Label, marking the end of two years of uncertainty for manufacturers. In 2016, the FDA initially announced a new regulatory definition for dietary fiber and stated that to be considered a source of fiber, isolated or synthetic non-digestible carbohydrates must have a demonstrated physiological health benefit.

More Articles
URL : http://www.nutritioninsight.com:80/news/Calcium-Imbalance-in-the-Mitochondria-Linked-to-Alzheimers-Disease.html?tracking=Nutrition%20and%20Health%20News