Damaged DNA no more? Scientists build shield for mitochondria

Scientists at the University of California, Riverside, have developed a novel chemical probe, named mTAP, that protects mitochondrial DNA (mtDNA) from damage caused by environmental toxins before it triggers chronic diseases. Unlike nuclear DNA, mtDNA is housed within mitochondria—the cell’s energy-producing organelles—and is vulnerable to damage from pollutants such as nitrosamines found in processed foods and cigarette smoke. When mtDNA is damaged, cells typically degrade it rather than repair it, leading to inflammation and tissue dysfunction linked to diseases like Alzheimer’s, diabetes, and heart failure. The new probe binds specifically to damaged mtDNA sites and blocks enzymes responsible for DNA breakdown, thereby reducing mtDNA loss without interfering with its normal function. The mTAP molecule is engineered with two components: one that detects and attaches to damaged mtDNA and another that ensures its delivery exclusively to mitochondria, sparing nuclear DNA. Laboratory tests demonstrated that cells treated with mTAP maintained higher levels of mtDNA after exposure to toxic stress