Figure 6.

USCs-exos inhibits ER stress-associated cell apoptosis and delays IDD in vivo. (a–c) The expression levels of GRP78 and CHOP in rat degeneration models as determined by Western blotting, and their relative quantities (b, c). (d) CT scans of the three adjacent IVDs of the rat's tail vertebra at 0, 4, and 8 weeks. The height of the intervertebral space in the experimental group was significantly lower than that of the USCs-exos group and the control group. (e) T2W1-weighted images of the MRI scans performed on the rat's tail at 0, 4, and 8 weeks. The degeneration of the experimental group was significantly stronger than that of the USCs-exos group and control group. (f) In the NMR detection, compared to the simple puncture, the CHOP amino acid residue leucine (Leu) in the IVDs punctured and injected with USCs-exos was significantly suppressed; caspase-3 amino acid residue aspartic acid. The content of the injected exosomes in the IVD is significantly lower than that of the pure puncture segment; lactic acid (Lac) levels were also significantly low. (g) The HE and Safranin O-fast green staining of the IVD revealed that the IVD with simple puncture was more disordered and looser than the annulus fibrosus injected with USCs-exos and contained a large number of inflammatory cells and scars. The degenerated nucleus pulposus tissue protrudes into the annulus fibrosus. (h) Masson staining, Safranin O-fast green staining, and HE staining all showed that the degree of degeneration of the IVD tissue of injected USCs-exos was less, and IHC showed that the expression of caspase-3 was lower. ^∗Compared to the control group, p < 0.05; ^#compared to the USCs-exos group, p < 0.05.