Diminished cartilage-lubricating ability of human osteoarthritic synovial fluid deficient in proteoglycan 4: Restoration through proteoglycan 4 supplementation.
Arthritis Rheum
; 64(12): 3963-71, 2012 Dec.
Article
en En
| MEDLINE
| ID: mdl-22933061
ABSTRACT
OBJECTIVE:
The purposes of this study were 1) to quantify the proteoglycan 4 (PRG4) and hyaluronan (HA) content in synovial fluid (SF) from normal donors and from patients with chronic osteoarthritis (OA) and 2) to assess the cartilage boundary-lubricating ability of PRG4-deficient OA SF as compared to that of normal SF, with and without supplementation with PRG4 and/or HA.METHODS:
OA SF was aspirated from the knee joints of patients with symptomatic chronic knee OA prior to therapeutic injection. PRG4 concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay (ELISA), and HA concentrations were measured using a commercially available ELISA. The molecular weight distribution of HA was measured by agarose gel electrophoresis. The cartilage boundary-lubricating ability of PRG4-deficient OA SF, PRG4-deficient OA SF supplemented with PRG4 and/or HA, and normal SF was assessed using a cartilage-on-cartilage friction test. Two friction coefficients (µ) were calculated static (µ(static, Neq) ) and kinetic (<µ(kinetic, Neq) >) (where N(eq) represents equilibrium axial load and angle brackets indicate that the value is an average).RESULTS:
The mean ± SEM PRG4 concentration in normal SF was 287.1 ± 31.8 µg/ml. OA SF samples deficient in PRG4 (146.5 ± 28.2 µg/ml) as compared to normal were identified and selected for lubrication testing. The HA concentration in PRG4-deficient OA SF (mean ± SEM 0.73 ± 0.08 mg/ml) was not significantly different from that in normal SF (0.54 ± 0.09 mg/ml). In PRG4-deficient OA SF, the molecular weight distribution of HA was shifted toward the lower range. The cartilage boundary-lubricating ability of PRG4-deficient OA SF was significantly diminished as compared to normal (mean ± SEM <µ(kinetic, Neq) > = 0.043 ± 0.008 versus 0.025 ± 0.002; P < 0.05) and was restored when supplemented with PRG4 (<µ(kinetic, Neq) > = 0.023 ± 0.003; P < 0.05).CONCLUSION:
These results indicate that some OA SF may have decreased PRG4 levels and diminished cartilage boundary-lubricating ability as compared to normal SF and that PRG4 supplementation can restore normal cartilage boundary lubrication function to these OA SF.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteoglicanos
/
Líquido Sinovial
/
Cartílago Articular
/
Osteoartritis de la Rodilla
/
Articulación de la Rodilla
Límite:
Aged
/
Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Arthritis Rheum
Año:
2012
Tipo del documento:
Article
País de afiliación:
Canadá