Small Extracellular Vesicles Derived from Adipocytes Attenuate Intervertebral Disc Degeneration in Rats by Rejuvenating Senescent Nucleus Pulposus Cells and Endplate Cells by Delivering Exogenous NAMPT

Figure 6

sEVs secreted from NAMPT-knockdown adipocytes exhibited attenuated function on rejuvenating senescent NPCs. (a) Representative micrographs of EPCs stained with SA-β-gal in different treatment groups. SA-β-gal-positive cells are shown in blue. Scale bar, 100 μm. (b) Percentage of SA-β-gal-positive cells. per group. (c) IF staining for Ki-67 (red). DAPI was used to stain the nuclei. Scale bar, 50 μm. (d) Percentage of Ki-67-positive cells. per group. (e) The expression of P16 was assessed by western blotting. (f) Densitometric quantification of the relative band intensity in (e). per group. (g) The expression of Collagen II, Aggrecan, MMP-3, and ADAMTS-4 was assessed by western blotting. (h) Densitometric quantification of the relative band intensity in (g). per group. (i) Quantification of mRNA expression for SASP (TNF-α, IL-6, and IL-8). per group. (j) NAMPT and Sirt1 expression were assessed by western blotting. (k) Densitometric quantification of the relative band intensity in (j). per group. (l) NAD⁺ levels in different treatment groups. ( compared with the IL-1β group; ^# compared with the IL--sEV group).

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