Therapeutic Treatment of Arthritic Mice with 15-Deoxy Δ^12,14-Prostaglandin J₂ (15d-PGJ₂) Ameliorates Disease through the Suppression of Th17 Cells and the Induction of CD4⁺CD25⁻FOXP3⁺ Cells

Figure 2

15d-PGJ₂ treatment ameliorates articular inflammation. Naïve or collagen-immunized and challenged DBA/1 mice were injected s.c. daily with vehicle or 15d-PGJ₂ (1 mg/Kg) for 7 days. At the end of treatment, mice were euthanized, the articular joints were harvested, and histopathologic analysis was performed. Knee joint sections were stained with H&E (a) or with safranin-O (c), a proteoglycan red marker, to reveal profound cartilage damage in the vehicle-treated mice (less proteoglycan staining) and the preservation of cartilage in 15d-PGJ₂-treated mice. Quantification of cellular infiltrate was performed by ImageJ software (NIH, USA) in 40 fields with 400x magnification for each animal/group (b). Morphometric histologic examination revealed markedly less cellular infiltration in the 15d-PGJ₂ mice than in the PBS-treated group. compared with naïve group. compared with arthritic mice treated with PBS (vehicle).