Table 1.

Activation of inflammatory response genes upon avulsion injury in murine cartilage explants^*

Gene	Gene induction in hip joint cartilage 4 hours after injury	P
Arg1	112.81 ± 93.58	≤0.05
Ccl2	12.39 ± 7.86	≤0.01
Il6	48.01 ± 30.49	≤0.01
Mmp3	3.28 ± 0.95	≤0.001
Il1b	3.67 ± 1.34	≤0.05
Adamts1	2.45 ± 1.0	≤0.01
Adamts4	1.25 ± 0.53	NS
Adamts5	2.01 ± 0.42	≤0.001
Tnfaip6 (Tsg6)	39.86 ± 22.10	≤0.01
Wisp2	0.52 ± 0.23 (↓)	≤0.001
Tnfrsf12a (Tweak)	11.68 ± 6.72	≤0.01
Ptgs2 (Cox2)	15.68 ± 8.47	≤0.001
Pdpn	5.89 ± 1.34	≤0.001
Timp1	4.61 ± 1.04	≤0.001
Cd14	16.38 ± 6.69	≤0.001
Mmp19	3.43 ± 1.76	≤0.01
Inhba	98.74 ± 56.61	≤0.001
Cd68	0.18 ± 0.10 (↓)	≤0.001

^* Hip cartilage explants from 5-week-old mice were avulsed and cultured for 4 hours in serum-free medium. RNA was extracted (4 cartilage samples pooled for each experimental data point), and reverse transcription–polymerase chain reaction was performed for a number of genes previously identified from a microarray study. Gene expression was normalized to the 18S housekeeping gene and expressed relative to the levels at time 0. Only 2 genes, Wisp2 and Cd68, were found to be down-regulated. Values are the mean ± SD fold change from time 0 (n = 6 experimental data points per group). P values were determined by unpaired t-test. NS = not significant.