Study tests matrix-gated rejuvenation

Researchers will test whether ageing human muscle cells can become molecularly younger only when the scaffold around them is soft, a question that could reshape rejuvenation experiments. They will grow organoids, three-dimensional miniature tissues, from muscle precursor cells donated by 68-year-olds across collagen matrices spanning 2-20 kilopascals, a measure of stiffness. A drug-controlled switch will activate OSK, three reprogramming factors, while matched locations are measured for stiffness and an epigenetic-age proxy, a DNA-mark pattern used to estimate cellular age. At day 14, a drop confined below 8 kilopascals, with young-like zones clustering in soft matrix, would support matrix-gated rejuvenation. A uniform drop or absent clustering would support extracellular-matrix-independent resistance.