Journal: The Journal of Biological Chemistry
Article Title: Live-cell imaging of DNA damage and cell cycle progression uncovers distinct responses during neural differentiation of hiPSCs
doi: 10.1016/j.jbc.2025.110328
Figure Lengend Snippet: Construction of human Focicle vector based on PiggyBac transposon system . A , design of PiggyBac transposon-based human Focicle vector. Tricistronic inserts of mRuby-hCdt1, Ypet-h53BP1 foci-forming region (FFR), and mTagBFP2-hGmnn are connected to P2A and T2A peptides and expressed under the CAG promoter. B , scheme of 53BP1, hCdt1, and hGmnn expression in cell cycle. C , generation of Focicle vector-integrated human RPE1-hTERT cells. Expression of 53BP1FFR ( green ), hCdt1 ( red ), and hGmnn ( blue ) was observed using a fluorescence microscope. hCdt1 positive cells indicate cells in G1 phase ( top ). hGmnn-positive cells indicate cells in the G2/M phase ( bottom ). Scale bars represent 10 μm. D , the distribution of DNA content in the hCdt1 - /hGmnn - ( red ), hCdt1 + ( orange ), and hGmnn + ( blue ) populations. E , Focicle RPE1-hTERT cells were exposed to 2 Gy gamma-ray, and 1 h after irradiation, 53BP1 foci were observed using fluorescence microscopy. F , Focicle RPE1-hTERT cells were treated with camptothecin (CPT) for 1 h, and 53BP1 foci were observed by fluorescence microscopy. G , cell cycle population after ionizing radiation (IR) exposure in Focicle RPE1-hTERT. Cells were untreated or treated with 2 Gy gamma-ray irradiation and analyzed at the indicated times after exposure. Cell cycle population was assessed by flow cytometry. hCdt1 positive cells were counted as G1 cells, and hGmnn-positive cells as G2 cells. Statistical analyses were performed using a one-way ANOVA and Tukey’s post hoc test. ns indicates no significant difference. ∗∗∗∗ p < 0.0001. All experiments were performed at least three times.
Article Snippet: The cells were blocked with 1% BSA/PBS-T at 4 °C for 1 h and stained with primary antibodies: SOX2 rabbit polyclonal antibody (1:500, Human Neural Stem Cell Immunocytochemistry Kit, A24354, Invitrogen, Thermo Fisher Scientific), Nestin mouse monoclonal antibody (1:500, Human Neural Stem Cell Immunocytochemistry Kit, A24354, Invitrogen, Thermo Fisher Scientific), MAP2 chicken polyclonal antibody (1:500, #ab5392, Abcam), Tublin β3 (Tuj1) mouse monoclonal antibody (#MMS-435P, Covance), 53BP1 rabbit polyclonal antibody (1:1000, #A300–272A; Bethyl), S139P γH2AX mouse monoclonal antibody (1:1000, #05–636; Merck Millipore), RAD51 mouse polyclonal antibody (1:500, #H00005888-B01P; Abnova), phosphor S2056 DNA-PKcs rabbit polyclonal antibody (1:500, #ab18192, Abcam) for 4 h–24 h at 4 °C.
Techniques: Plasmid Preparation, Expressing, Fluorescence, Microscopy, Irradiation, Flow Cytometry