Experts stop mice livers from ageing

Halt Accumulation Of Harmful Proteins Inside Organ’s Cells

 

Paris: Researchers have blocked the ageing process in mice livers by halting the accumulation of harmful proteins inside the organ’s cells, according to a groundbreaking study released on Sunday.
   This is the first time that age-related decline due to protein build-up has been arrested in an entire organ or in a live animal, it said.
   The findings could pave the way to therapies for life-threatening liver conditions common in late stages of life, the study said. They could even lead to a recipe for boosting longevity.
   In experiments, livers in genetically modified mice 22-to-26 months old — the equivalent of octogenarians in human years — cleaned blood as efficiently as those in animals a quarter their age. By contrast, the livers of normal mice in a control group began to fail.
   The benefits of restoring the cleaning mechanisms found inside all cells could extend far beyond a single organ, said the study’s main architect Ana Maria Cuervo, a researcher at the Albert Einstein College of Medicine at Yeshiva University in New York City.
   “Our findings are particularly relevant for neurodegenerative disorders such as Parkinson’s and Alzheimer’s,” she said. Published in the British journal Nature Medicine, it shows that the failure to remove damaged proteins are a cause, and not the consequence, of the reduced functions that characterises the biological endgame.
   Cuervo’s experiments also point to at least one way those functions can be fixed.
   In healthy organisms, a surveillance system inside cells called chaperone-mediated autophagy locates, digests and destroys damaged proteins.
   Specialised molecules — the “chaperones” — ferry the harmful material to membranebound sacs of enzymes within the cells known as lysosomes.
   Once the cargo has been “docked”, a receptor molecule transfers the protein into the sac, where it is rapidly digested. With age, these receptors stop working as well, resulting in a dangerous build-up of faulty proteins that has been linked — in the liver — to insulin resistance as well as the inability to metabolise sugar, fats or alcohol. The same breakdown can also impair the liver’s ability to remove the toxic build-up from medication.
   In genetically modified mice, Cuervo compensated for the loss of the receptors in the animals by adding extra copies. “That was enough to maintain a clean liver and to prove that if you keep your cells clean they work better,” she explained. AGENCIES