Carnitine palmitoyltransferase 1A facilitates the senescence of human dental pulp stem cells by Parkin succinylation-mediated mitophagy

Figure 4 Mitophagy is a necessary process for carnitine palmitoyltransferase 1A to regulate dental pulp stem cell senescence. A and B: Dental pulp stem cells (DPSCs) at passage 15 (p15) were transfected with shNC and shCPT1A and treated with mitophagy inhibitor Mdivi-1, senescence in DPSCs was observed using senescence associated β-galactosidase staining; C and D: The levels of aging markers (p53, p21, and p16) were measured using immunoblotting; E: Transmission electron microscopy evaluation of mitophagy; F: Quantification of autophagic vacuoles per cell; G and H: The levels of mitophagy markers (PINK1, Parkin, and LC3B) were measured using immunoblotting; I: Immunofluorescent assay was conducted to visualize mitochondria (red dots) and lysosomes (green dots). n = 3/group; P < 0.001 and P < 0.05 indicate statistically significant differences. CPT1A: Carnitine palmitoyltransferase 1A; SA-β-gal: Senescence associated β-galactosidase.