Table 1.
Comparison of OA score in young mature adult and old mice.
| OASRI Grade |
Histological Findings (Safranin-O Staining) |
Young Mature Adult | Old | ||
|---|---|---|---|---|---|
| Nrf2-WT (n = 6) |
Nrf2-KO (n = 5) |
Nrf2-WT (n = 11) |
Nrf2-KO (n = 8) |
||
| Male 2 Female 4 |
Female 5 | Male 5 Female 6 |
Male 4 Female 4 |
||
| 0 | Normal cartilage | 6 | 5 | 2 | − |
| 0.5 | Loss of staining without structural changes | − | − | 8 | 2 |
| 1 | Small fibrillations without cartilage loss | − | − | 1 | 3 |
| 2 | Vertical clefts and/or erosion down to the layer just below the surface and some loss of surface lamina | − | − | − | 3 |
| 3 | Extension of vertical tears and/or erosions to the calcified cartilage (<25%) | − | − | − | − |
| 4 | Extension of vertical tears and/or erosions to the calcified cartilage (25−50%) | − | − | − | − |
| 5 | Extension of vertical tears/erosions to the calcified cartilage (50−75%) | − | − | − | − |
| 6 | Extension of vertical tears/erosions to the calcified cartilage (>75%) | − | − | − | − |
OARSI, the Osteoarthritis Research Society International.