Journal: bioRxiv
Article Title: DNA damage drives a unique, Alzheimer’s disease-relevant senescent state in neurons
doi: 10.64898/2026.04.02.716205
Figure Lengend Snippet: Protein level differences in senescence-associated markers further distinguish neuronal and fibroblast responses to DNA damage (A) Schematic of immunocytochemistry (ICC) performed after IR in healthy dermal fibroblasts and iNs from the same donors (donors: A27, A48, ID98; 3 technical replicates per donor in each condition). 0.2% FBS low serum (LS) treatment was applied to CTL and IR fibroblasts to induce quiescence 72 hours prior to collection. (B) IR iNs and IR fibroblasts were stained for p21 (top left), p16 (top right), LMNB1 (bottom left), and HMGB1 (bottom right). Mean nuclear fluorescence intensity was quantified. (C) Nuclear area of IR iNs and IR fibroblasts quantified by DAPI staining (donors: A27, A48, ID98, 18 technical replicates per donor in each condition). (D) PSD95 staining for IR iNs and IR fibroblasts, imaged by confocal microscopy, and analyzed by Imaris to detect PSD95 spots on MAP2-positive dendrites and normalize to dendrite surface area. Two donors used for PSD95 staining (donors: A27, A48; 3 technical replicates per donor in each condition; donor A48 images and quantification shown in ). Tracks on MAP2 traced in Illustrator. All iNs imaged were quantified with automatic MAP2 tracing to measure p21, p16, LMNB1, HMGB1, and DAPI only in neuronal nuclei or PSD95 only in neuronal dendrites (Supp. Fig. 5). Imaging was performed on the Harmony Operetta CLS system at 63X unless otherwise stated. Nuclear intensity quantification of images performed by the Harmony analysis system and nuclei number after IR provided in Supp. Fig. 4. Statistics were calculated using multiple unpaired t-tests using Welch’s correction with Holm–Šídák adjustment for multiple testing with alpha = 0.05. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, ns: not significant, nd: not detected.
Article Snippet: Cells were then incubated with primary antibodies at 4°C overnight (γH2AX, abcam, ab81299, 1:250; 1:1000; pATM, Life Technologies, MA1-2020, 1:250; p21, abcam, ab109520, 1:100; p16, abcam, ab270058, 1:50; LMNB1, abcam, ab229025, 1:1000; HMGB1, abcam, ab79823, 1:250; 53BP1, abcam, ab175933, 1:200, PSD95, Life Technologies, MA1-046, 1:300; MAP2, Novus Biologicals, NB300-213, 1:400).
Techniques: Immunocytochemistry, Staining, Fluorescence, Confocal Microscopy, Imaging