Fig. 9

POT1 prevents DDR in human HSC. a Expression of POT1 in hCB CD34⁺ cells and LT-HSCs (Lin^–CD34⁺CD38⁻CD45RA⁻CD90⁺CD49f⁺). b hCB-derived LT-HSCs were cultured with MTM-POT1. After 10 days of culture, cells were isolated and re-cultured in methylcellulose medium (200 cells per dish). The number of CFU-C and HPP-CFC (>1.0 mm, >2.0 mm) are shown. Data are expressed as the mean ± SD (n = 3, *p < 0.01 by t-test). Representative data from three independent experiments are shown. c, d hCB LT-HSCs were cultured for 10 days with control MTM protein or MTM-POT1. After 10 days of culture, LT-HSCs were re-isolated and number of TIF was examined. c Immunocytochemical staining of TRF1 (green), 53BP1 (red), and TOTO3 (blue). Scale bar, 2 μm (left). Frequencies of TIFs after 10 days of culture (right). Data are expressed as the mean ± SD (n = 100: control, n = 100: MTM-POT1, *p < 0.01 by t-test). Representative data from 2 independent experiments are shown. d Immunocytochemical staining of TRF1 (green), RPA32 (red), and TOTO3 (blue). Scale bar, 2 μm (left). Frequencies of TIFs after 10 days of culture (right). Data are expressed as the mean ± SD (n = 110–120: control, n = 110: MTM-POT1, *p < 0.01 by t-test). Representative data from two independent experiments are shown