Spermidine Inhibits Joints Inflammation and Macrophage Activation in Mice with Collagen-Induced Arthritis

Figures & data

Figure 1 Effects of spermidine on swelling of paws of collagen-induced arthritis (CIA) mice. (A) Effect of spermidine on the thickness of footpads of CIA mice. Data are presented as mean ± standard deviation (SD) from five animals and analyzed using repeated measures analysis of variance (ANOVA). (B) Changes in arthritis score after treatment. Data are presented as mean ± SD from five animals and analyzed using repeated measures ANOVA. (C) The increase in footpad thickness after spermidine treatment compared to before modeling. Dates are presented as median with interquartile ranges and analyzed using the Kruskal–Wallis test. *P < 0.05, **P < 0.01, ***P < 0.001 vs CIA control group.

Abbreviations: CIA, type II collagen (CII)-induced arthritis; SPD, spermidine; DEX, dexamethasone.

Figure 2 Effects of spermidine on the release of IL-10, IL-1β, and IL-6 in the serum of collagen-induced arthritis (CIA) mice. (A) IL-10 levels; (B) IL-1β levels; (C) IL-6 levels. Data are presented as mean ± standard deviation from five animals and analyzed using single-factor analysis of variance followed by the least significant difference test. **P < 0.01, ***P < 0.001 vs CIA control group.

Abbreviations: CIA, type II collagen (CII)-induced arthritis; SPD, spermidine; DEX, dexamethasone.

Table 1 Histological Scores of Each Group

Histological Feature	CIA Control	SPD-H	SPD-L	DEX	Normal Control	P
Proliferation of synovial cells	1.90±0.37	1.30±0.41	1.50±0.22	1.50±0.39	0.40±0.19**	0.047
Non-foreign-body giant cells	0.40±0.19	0.40±0.24	0.40±0.10	0.30±0.12	0.00±0.00	0.322
Lymphoid cell infiltration	0.30±0.20	0.30±0.12	0.50±0.16	0.30±0.12	0.20±0.12	0.704
Plasma cell infiltration	0.70±0.12	0.30±0.12	0.90±0.29	0.40±0.19	0.40±0.24	0.240
Neovascularization	1.20±0.20	0.40±0.10**	0.90±0.10	0.40±0.19**	0.10±0.10***	<0.001
Mesenchymoid transformation	1.00±0.35	0.60±0.19	1.00±0.35	0.50±0.22	0.30±0.20	0.306
Fibrinoid necrosis	0.90±0.19	0.10±0.10***	0.10±0.10***	0.30±0.12**	0.00±0.00***	<0.001
Total	6.40±0.81	3.40±0.87*	5.30±0.73	3.70±0.73*	1.40±0.58***	0.002

Notes: Data are recorded as mean ± SD from five animals and analyzed using single-factor analysis of variance followed by the least significant difference test; *P < 0.05, **P < 0.01, ***P < 0.001 vs CIA control group.

Abbreviations: CIA, type II collagen (CII)-induced arthritis; SPD, spermidine; DEX, dexamethasone.

Figure 3 Histopathological observations of ankle joints. (A) Representative histological sections of ankle joints stained with HE. (B) Synovial pathology score of each group. Data are presented as mean ± standard deviation from five animals and analyzed using single-factor analysis of variance followed by the least significant difference test. *P < 0.05, ***P < 0.001 vs CIA control group.

Abbreviations: CIA, type II collagen (CII)-induced arthritis; SPD, spermidine; DEX, dexamethasone.

Table 2 Number of Immune-Positive Cells (%) in Each Group

	CIA Control	SPD-H	SPD-L	Normal Control	P
F4/80	13.24 (10.36, 23.30)	6.56 (3.01, 11.78)	7.65 (2.76, 13.95)	9.09 (4.20, 12.13)	0.118
iNOS	21.28 (13.48, 26.42)	2.66 (0.49,12.56)*	5.66 (4.69, 11.95)	6.57 (2.15, 17.74)	0.015
CD206	10.19 (6.44, 29.87)	13.55 (6.83, 19.63)	7.87 (3.99, 15.27)	3.56 (2.93, 9.54)	0.744

Notes: Data are presented as median with interquartile ranges and analyzed using the Kruskal–Wallis test; *p < 0.05 vs CIA control group.

Abbreviations: CIA, type II collagen (CII)-induced arthritis; SPD, spermidine; DEX, dexamethasone.

Figure 4 Immunohistochemical results of the ankle synovial tissue in each group (SP×400).