Wnt makes stem cells act their age

The Wnt pathway helps embryos get into shape, but its continued activation during adulthood saps the stem cells that refurbish tissues, according to two studies. The findings implicate Wnt in the stem cell failure that might be a cause of aging.

Both groups chanced on the connection to Wnt, whose many functions include promoting differentiation and cell division. Hongjun Liu, Toren Finkel (National Heart, Lung, and Blood Institute, Bethesda, MD), and colleagues were studying mice that lack the protein klotho. The animals die young after showing signs of premature aging such as hardened arteries. The researchers detected a surge in cellular senescence in locations where stem cells are proliferating, such as the skin, small intestine, and bone marrow.

Klotho and...