As we age, some cells enter a senescent state, stop dividing but do not die, and these “zombie cells” are linked to cancer, tissue degeneration and inflammatory diseases. MIT researchers combined Raman microscopy with single‑cell spatial RNA sequencing to create a non‑invasive way to detect senescence biomarkers.
Raman microscopy shines near‑infrared or visible light on cells to obtain their chemical composition without destroying them, while spatial RNA sequencing maps where genes are active. By merging the two, the team profiled senescent cells in skin and lung tissue from 2‑month‑old and 26‑month‑old mice.
The most striking change in older tissues was increased lipid synthesis and accumulation; skin cells also showed altered muscle‑contraction and collagen‑matrix remodeling pathways, whereas aged lung tissue exhibited up‑regulated immune activation and inflammation genes. The researchers paired Raman peaks that correspond to specific chemical bonds with key gene signatures to build a “barcode” that can quickly identify senescent cells.
This barcode focuses on a few highly informative Raman bands, allowing senescent cells to be pinpointed in a spectrum and opening the door to diagnostic applications. To move toward clinical use, the team is developing a faster Raman imaging system, aiming to cut the current 30‑hour per square‑millimeter analysis time down to a real‑time scale, potentially enabling endoscopic detection of senescence.
The work was funded by the National Institutes of Health and Massachusetts General Hospital as part of the NIH Cellular Senescence Network, which seeks comprehensive understanding of senescence to develop anti‑aging therapies. Review