Table 3: Overview of main experimental and clinical data on adipocytokines in OA.

AdipocytokineModel Finding(s)Authors

AdiponectinHuman (synovial tissue) Strongly expressed in synovium and adipose tissue
Stimulates the release of IL-6 and pro-MMP-1 by synovial fibrobasts
Ehling et al. [62]
Human (plasma, SF, synovial tissue)Percentage of HMW adiponectinin SF lower than in plasma, while that of the hexamer form similar and the trimer form higher
Up-regulation of tissue TIMP-2 and down-regulation of IL-1 -induced MMP-13 in chondrocytes
Chen et al. [113]
Murine (chondrocytes)Induces proinflammatory and prodegradative mediators in murine chondrogenic cell linesLago et al. [112]
Human (plasma)Higher levels than RA patients and healthy controlsLaurberg et al. [84]
Human (serum)Higher levels in female patients with erosive than in those with nonerosive disease Filková et al. [124]
Human (synovial tissue)Expression levels of AdipoR1 and AdipoR2 significantly higher in lesional than in nonlesional cartilage
Stimulates the release of nitric oxide, MMP-1, -3, and -13 by chondrocytes
Kang et al. [111]
Human (plasma, SF)Levels in plasma higher with respect to matched SF
Levels in plasma and SF inversely correlated with disease severity
Honsawek and Chayanupatkul [122]
Human (synovial tissue)Induces gene expression and synthesis of proinflammatory mediators in fibroblasts to a lesser extent than RASF (adiponectin isoforms)Frommer et al. [32, 64]
Human (plasma, cartilage tissue)Plasma levels and release from cartilage higher in patients with severe disease
Plasma levels positively correlated with biomarkers of OA
Koskinen et al. [125]
Human (serum)Mean level significantly lower in patients with progression compared with those without progressionYusuf et al. [123]
Human (serum)No difference in levels in patients with radiographic and nonradiographic OAChoe et al. [126]
Human (serum)Higher levels in patients as compared to controls
Association of serum levels with female gender and BMI
de Boer et al. [127]

LeptinHuman (serum)Positive correlation between serum levels and BMI
No correlation between serum levels and visual analogue pain scale for the lower-limb afflicted patients and stage of disease
Wisłowska et al. [91]
Human (SF)Median concentrations significantly higher in patients compared to controls
Positive correlation between SF levels and severity of disease
Ku et al. [120]
Human (serum)Association with increased levels of bone formation biomarkersBerry et al. [119]
Human (serum)Mean level slightly higher in patients with progression compared with those without progressionYusuf et al. [123]
Human (serum)Higher levels in patients as compared to controls
Association of serum levels with female gender and BMI
de Boer et al. [127]
Human (cultured chondrocytes)Stimulates MMP expression in chondrocytes cultured with WAT-conditioned media Hui et al. [106]
Human (serum)Association with prevalent and incident OAKarvonen-Gutierrez et al. [121]

ResistinHuman (synovial tissue)
Mouse (cartilage explants)
Expressed at the same extent of healthy controls
Incubation with the conditioned media from monocytes treated with recombinant human resistin caused a dose-dependent proteoglycan release
Lee et al. [116]
Human (serum)Mean level not different in patients with progression and those without progressionYusuf et al. [123]
Human (serum)Higher levels in patients with radiographic subchondral erosions than in nonradiographic OA
Resistin-treated cartilage released proinflammatory mediators
Choe et al. [126]
Human (serum)Higher levels in patients as compared to controlsde Boer et al. [127]

MMP: matrix metalloproteinase; HMW: high molecular weight; SF: synovial fluid; TIMP-2: tissue inhibitor of metalloproteinase-2; RA: rheumatoid arthritis; RASF: rheumatoid arthritis synovial fibroblasts; OA: osteoarthritis; BMI: body mass index; WAT: white adipose tissue.