Study measures matrix–epigenetic lag

Can a cell’s molecular age become younger before its surrounding support material follows? This proposed study tests that timing gap in aged human skin fibroblasts, connective-tissue cells that make surrounding proteins. Cells from three donors will receive doxycycline, a drug that switches on three reprogramming factors: OCT4, SOX2 and KLF4. For 28 days, researchers will collect cells and culture fluid every 48 hours, using six wells per time point. Chemical marks on DNA will estimate molecular age, while the fluid’s fibronectin:laminin ratio will track secretion of two matrix proteins. A gap greater than seven days, with bootstrap p below 0.05, would support a measurable mismatch window. Similar timing would mean this secretory readout has little or no window. Deposited matrix requires separate measurement.