Novel drug makes mice skinny even on sugary, fatty diet: Compound limits magnesium transport in cellular power plants called mitochondria.

“When we give this drug to the mice for a short time, they start losing weight. They all become slim,” said Madesh Muniswamy, PhD, professor of medicine in the health science center’s Joe R. and Teresa Lozano Long School of Medicine.

Findings by the collaborators, also from the University of Pennsylvania and Cornell University, were published Feb. 27 in the high-impact journal Cell Reports. Muniswamy, director of the Center for Mitochondrial Medicine at UT Health San Antonio, is the senior author.

Fourth most common element

The research team discovered the drug by first exploring how magnesium impacts metabolism, which is the production and consumption of energy in cells. This energy, called ATP, fuels the body’s processes.

Magnesium is the fourth most abundant element in the body after calcium, potassium and sodium, and plays many key roles in good health, including regulating blood sugar and blood pressure and building bones. But the researchers found that too much magnesium slows energy production in mitochondria, which are cells’ power plants.

“It puts the brake on, it just slows down,” said co-lead author Travis R. Madaris, doctoral student in the Muniswamy laboratory at UT Health San Antonio.

Deleting MRS2, a gene that promotes magnesium transport into the mitochondria, resulted in more efficient metabolism of sugar and fat in the power plants. The result: skinny, healthy mice.

Liver and adipose (fat) tissues in the rodents showed no evidence of fatty liver disease, a complication related to poor diet, obesity and type 2 diabetes.

Small-molecule agent

The drug, which the researchers call CPACC, accomplishes the same thing. It restricts the amount of magnesium transfer into the power plants. In experiments, the result was again: skinny, healthy mice. UT Health San Antonio has filed a patent application on the drug.

The mice served as a model system of long-term dietary stress precipitated by the calorie-rich, sugary and fatty Western diet. The familiar results of this stress are obesity, type 2 diabetes and cardiovascular complications.

“Lowering the mitochondrial magnesium mitigated the adverse effects of prolonged dietary stress,” said co-lead author Manigandan Venkatesan, PhD, postdoctoral fellow in the Muniswamy lab.

Joseph A. Baur, PhD, of the University of Pennsylvania and Justin J. Wilson, PhD, of Cornell are among the collaborators. “We came up with the small molecule and Justin synthesized it,” Madaris said.

Significant implications

“These findings are the result of several years of work,” Muniswamy said. “A drug that can reduce the risk of cardiometabolic diseases such as heart attack and stroke, and also reduce the incidence of liver cancer, which can follow fatty liver disease, will make a huge impact. We will continue its development.”

Funders of this project include the National Institutes of Health, the U.S. Department of Defense and the San Antonio Partnership for Precision Therapeutics.