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."

Related Articles

Business News

Natural ingredients key for Evonik's growth strategy

23 Aug 2017 --- With an expanding portfolio that includes omega 3 fatty acids and anthocyanin-rich extracts, global specialty chemicals company Evonik Industries is boldly expanding its presence in the Advanced Food Ingredients market. NutritionInsight spoke with Dr. Ludger Eilers, Director of Evonik Health Care’s Food Ingredient Segment, about this move as well as the company’s latest R&D projects and ingredients.

Nutrition & Health News

Plant-based diets associated with lower levels of plasma lipids by meta-analysis

23 Aug 2017 --- Consumption of vegetarian diets, particularly vegan diets, is associated with lower levels of plasma lipids, which could offer individuals and healthcare professionals an effective option for reducing the risk of heart disease or other chronic conditions. This is the finding of a review and meta-analysis by Dr. Yoko Yokoyama, Ms. Susan Levin and Dr. Neil Barnard.

Nutrition & Health News

"Silent" food product reformulation key to helping consumers buy fewer calories

23 Aug 2017 --- Without notifying consumers explicitly, supermarkets could help their customers consume fewer calories by making small changes to the recipes of own-brand food products to reduce the calories contained in the product. This is according to researchers at the University of Copenhagen, who say that so-called “silent” product reformulation may be a promising strategy to allow food retailers to contribute to lower calorie intake in the population.

Food Ingredients News

Nexira Fibregum receives FODMAP friendly certification

23 Aug 2017 --- Natural and organic ingredients company Nexira has announced that its Fibregum product has been certified FODMAP friendly in Australia. The company describes Fibregum as an “all-natural range, with a guaranteed minimum content of 90 percent dietary fibers.” Nexira notes that the FODMAP Friendly program is the only registered certification trademark in the world, making Fibregum’s certification big news for the company. The program’s laboratory tests the FODMAP levels in food and gives the certification to the ones low in FODMAP.

Nutrition & Health News

Adding oats to gluten-free diet is safe for celiac sufferers, study review suggests

23 Aug 2017 --- No evidence has been found by researchers that addition of oats to a gluten-free diet affects symptoms, histology, immunity or serologic features of patients with celiac disease. This is according to a systemic review and meta-analysis of clinical and observational studies.

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