MIT researchers have developed a noninvasive method for identifying senescent, or “zombie,” cells that stop dividing but remain alive and can accumulate with age. The approach combines Raman microscopy, which measures cellular chemistry without destroying the sample, with single-cell and spatial gene-expression data from the same cells. In experiments on skin and lung tissue from young and old mice, the researchers found increased lipid synthesis and lipid accumulation in older cells, along with tissue-specific changes involving collagen and extracellular-matrix remodeling in skin and immune activation and inflammation in lung tissue. They used the combined measurements to identify Raman spectral peaks and gene signatures associated with senescence, creating a barcode that could allow faster screening using a limited set of informative Raman bands. The work could support future diagnostics and research into therapies, but it remains at the mouse-cell and mouse-tissue stage. The team is adapting the method for human tissue and developing a faster imaging system; analyzing a roughly one-square-millimeter sample currently takes about 30 hours. A future endoscope for detecting senescent cells is presented as a possibility, not an available clinical device.
