| External factors: | PM2.5 |
| Aging type: | Accelerate |
| Aging characteristic: |
| Category: | Other |
| Phenotype: | Aging |
| Experiment: | SA-β-gal activity assay//Western blot//Cell morphological analysis//Colony formation assay//DAPI staining |
| Description: | PM2.5-treated cells exhibited β-galactosidase activity in the cytosol, a characteristic of cellular senescence, as evidenced by higher levels of green signal in PM2.5-treated cells than in untreated cells. Moreover, the expression of p16INK4A, a CDK inhibitor and senescence inducer, was considerably higher in PM2.5-treated cells than in the corresponding untreated cells . Furthermore, PM2.5-treated cells showed characteristics of cellular senescence, including an enlarged and flattened cell shape and irregular size, low proliferation, and decreased colony-forming ability. Chromatin in senescent cells undergoes large-scale rearrangement, forming dense nuclear domains called SAHF26. PM2.5-treated cells displayed significantly more SAHF-like chromatin foci in the nuclei than the controls. |
| Target gene: | P16INK5A//TET//DNMT |
| R-EF-Target gene: | Upregulation//Upregulation//Downregulation |
| Official symbol(s): | P16INK5A//TET//DNMT1 |
| Target gene experiment: | RT-PCR//Western blot//Immunofluorescence |
| Target gene description: | The mRNA expression of p16INK4A, a senescence inducer, was upregulated in PM2.5-treated cells from 3?h onwards, continuing up to 72?h. In agreement with the RT-PCR results, western blotting also revealed strong induction of the p16INK4A protein.DNMT1 and DNMT3B expression decreased 3–12?h after PM2.5 treatment, whereas TET1 expression increased transiently at 3–12?h after PM2.5 treatment. The decrease in the expression of DNMT1 and DNMT3B and the increase in TET1 observed at 3?h after treatment by western blot analysis was also confirmed by immunofluorescence. |
| Regulatory pathway: | AhR-ROS |
| R-EF-Pathway: | Activation |
| Official symbol(s): | AHR-ROS |
| Pathway experiment: | Western blot//Immunofluorescence |
| Pathway description: | Immunoblotting data showed that the nuclear accumulation of AhR in PM2.5-treated cells occurred at 0.5?h and continued until 24?h. The nuclear accumulation of AhR was confirmed by immunofluorescence at 0.5?h . In response to PM2.5, the ROS level increased from 0.5?h, and the increase continued until 24?h in HaCaT cells and NHEKs, concomitant with AhR expression. |
Annotation: