Blood pressure drug may treat muscular dystrophy

Genetically engineered mice with Marfan syndrome were given losartan, a hypertension drug. The drug was found to dramatically strengthen the aorta, the major artery carrying blood away from the heart, and prevent enlargement and risk of bursting, a condition known as aortic aneurysm. A clinical trial to assess how effective losartan is for treating people with Marfan will launch within weeks.

“In addition to the aortic defect, children with severe Marfan syndrome often have very small, weak muscles, and adults with Marfan often can’t gain muscle mass despite adequate nutrition and exercise,” said Harry Dietz, a professor at the McKusick-Nathans Institute of Genetic Medicine at The Johns Hopkins University School of Medicine.

Dietz and his colleagues had previously discovered that many features of Marfan syndrome, including aortic aneurysm, arise from excess activity of TGF-beta, a protein that instructs cell behavior. First, the research team injected Marfan mice with a protein that binds TGF-beta and renders it inactive. The team then treated Marfan mice with losartan, a medication known to block TGF-beta activity. Losartan treatment over six months vastly improved strength, according to Dietz.

The team then treated one group of Duchenne muscular dystrophy mice with TGF-beta-blocking protein and another group with losartan. Both groups of treated mice showed completely restored ability to regenerate muscle after injury, whereas untreated mice had large patches of scar tissue in place of muscle.