Fig. 8

Blockage of NRF2 partially abolished the regenerative effects of psoralen on irradiated bone defects in mice. The microCT results showed that the volume of newborn bones in both the groups of SSCs treated with psoralen and the irradiated SSCs psoralen was lower in the presence of ML385 than in the absence of ML385 (a and b). The results of HE, Masson, and Col-I staining showed that ML385 administration partially abolished the ability of psoralen to promote the rebuilding of bone structure and collagen formation in the new bones of bone defects caused by irradiation (c–e). The number of OCN-labeled OBs decreased in the presence of ML385 compared to their counterparts—without NRF2 blockade (f and g). All data are shown as the mean ± SD. **P < 0.01, *P < 0.05. The scale bars represent 2 mm (a), 500 μm (2c–e), and 200 μm (2f), respectively. Control: irradiated bone defect; Vector: microgel; SSC: skeletal stem cell; IR: irradiation; Pso: psoralen; BV/TV: bone volume per tissue volume; BMD: bone mineral density; Ob.S/B.S: osteoblast surface per bone surface; and Ob.N/B.Pm: number of osteoblasts per bone perimeter