Ernatant was stored at 220uC until measurement of cytokine levels.Measurement of cytokine levelsCytokine levels of TNF-a, IL-1b, IL-6 and IL-12 were measured in macrophage culture supernatant using Luminex multianalyte technology, (Bio-Rad Laboratories, Hercules, USA) according to the manufacturer’s instructions. Protein levels were calculated from a standard curve of known cytokine concentrations. Data analysis was performed using Bio-Plex Manager software (Bio-Rad Laboratories).Measurement of99MTechnetium-uptakeUptake of 99MTechnetium (Tc) was measured as described previously [20] to determine the swelling of the knee joint that occurs as a consequence of 
inflammation. Mice were sedated with 4.5 chloral hydrate and intraperitoneally injected with 20 mCi of 99M Tc. After 30 minutes, the amount of radioactivity was determined by external gamma counting. Knee joint swelling was expressed as the ratio of 99MTc uptake in the right (R) and left (L) knee joint of mice with an unilaterally induced arthritis in the right knee joint. Right-left ratios .1.1 were taken to indicate significant swelling of the right knee joint.Flow cytometrySurface levels of CD86 were measured by flow cytometry. Cells were counted, washed and incubated with PE-labeled rat antimouse CD86 antibody (BD Pharmingen) for one hour. After washing, labeling of the cells was measured by flow cytometry using a FACSCalibur (BD Biosciences). Mean fluorescence intensity (MFI) was corrected against a relevant isotype control staining.Sacrifice and tissue collectionMice were sacrificed by cervical dislocation and arthritic knee HIF-2��-IN-1 web joints were isolated and fixed in 10 formalin for 4 days for histological analysis. For RNA isolation, biopsies with a diameter of 3 mm were punched out of the synovium from both the lateral and medial side of the arthritic knee joints as described previously [21] and were stored in liquid nitrogen until RNA isolation.RNA isolationRNA was isolated with a RNeasy kit (Qiagen, Venlo, the Netherlands). Isolated nucleic acids were treated with DNAse before being reverse transcribed into 1407003 complementary DNA using oligo (dT) primers and MMLV reverse transcriptase.HistologyAfter fixation, total knee joints were decalcified in 5 formic acid and thereafter embedded in paraffin. Standard frontal sections of 7 mm were mounted on superfrost slides (MenzelGlaser, Braunschweig, Germany) and stained with hematoxylin ?and eosin (HE). The severity of joint get JW 74 inflammation was determined as described previously [22], by scoring the amount of cellular infiltration into the synovium using an arbitrary scale (0?), for three representative knee joint sections for each mouse (5 mice for each treatment group). Scoring was performed in a blinded manner by two independent observers: 0, no cells; 1, mild cellularity; 2, moderate cellularity; 3, maximal cellularity.Microarray analysisThe microarray was performed as described previously [10], using Affymetrix oligonucleotide arrays. Generation of biotinylated complementary RNA and subsequent hybridization, washing and staining of oligonucleotide arrays (Affymetrix, Santa Clara, CA) were performed according to the Affymetrix Expression Analysis Technical Manual for 1-cycle amplification. The arrays were then scanned using a laser scanner (GeneChip Scanner; Affymetrix) and analyzed using Affymetrix GeneChip Operating Software (GCOS; version 1.4) according to the manufacturer’s instructions. Gene expression relative to the house-keeping gene.Ernatant was stored at 220uC until measurement of cytokine levels.Measurement of cytokine levelsCytokine levels of TNF-a, IL-1b, IL-6 and IL-12 were measured in macrophage culture supernatant using Luminex multianalyte technology, (Bio-Rad Laboratories, Hercules, USA) according to the manufacturer’s instructions. Protein levels were calculated from a standard curve of known cytokine concentrations. Data analysis was performed using Bio-Plex Manager software (Bio-Rad Laboratories).Measurement of99MTechnetium-uptakeUptake of 99MTechnetium (Tc) was measured as described previously [20] to determine the swelling of the knee joint that occurs as a consequence of inflammation. Mice were sedated with 4.5 
chloral hydrate and intraperitoneally injected with 20 mCi of 99M Tc. After 30 minutes, the amount of radioactivity was determined by external gamma counting. Knee joint swelling was expressed as the ratio of 99MTc uptake in the right (R) and left (L) knee joint of mice with an unilaterally induced arthritis in the right knee joint. Right-left ratios .1.1 were taken to indicate significant swelling of the right knee joint.Flow cytometrySurface levels of CD86 were measured by flow cytometry. Cells were counted, washed and incubated with PE-labeled rat antimouse CD86 antibody (BD Pharmingen) for one hour. After washing, labeling of the cells was measured by flow cytometry using a FACSCalibur (BD Biosciences). Mean fluorescence intensity (MFI) was corrected against a relevant isotype control staining.Sacrifice and tissue collectionMice were sacrificed by cervical dislocation and arthritic knee joints were isolated and fixed in 10 formalin for 4 days for histological analysis. For RNA isolation, biopsies with a diameter of 3 mm were punched out of the synovium from both the lateral and medial side of the arthritic knee joints as described previously [21] and were stored in liquid nitrogen until RNA isolation.RNA isolationRNA was isolated with a RNeasy kit (Qiagen, Venlo, the Netherlands). Isolated nucleic acids were treated with DNAse before being reverse transcribed into 1407003 complementary DNA using oligo (dT) primers and MMLV reverse transcriptase.HistologyAfter fixation, total knee joints were decalcified in 5 formic acid and thereafter embedded in paraffin. Standard frontal sections of 7 mm were mounted on superfrost slides (MenzelGlaser, Braunschweig, Germany) and stained with hematoxylin ?and eosin (HE). The severity of joint inflammation was determined as described previously [22], by scoring the amount of cellular infiltration into the synovium using an arbitrary scale (0?), for three representative knee joint sections for each mouse (5 mice for each treatment group). Scoring was performed in a blinded manner by two independent observers: 0, no cells; 1, mild cellularity; 2, moderate cellularity; 3, maximal cellularity.Microarray analysisThe microarray was performed as described previously [10], using Affymetrix oligonucleotide arrays. Generation of biotinylated complementary RNA and subsequent hybridization, washing and staining of oligonucleotide arrays (Affymetrix, Santa Clara, CA) were performed according to the Affymetrix Expression Analysis Technical Manual for 1-cycle amplification. The arrays were then scanned using a laser scanner (GeneChip Scanner; Affymetrix) and analyzed using Affymetrix GeneChip Operating Software (GCOS; version 1.4) according to the manufacturer’s instructions. Gene expression relative to the house-keeping gene.
