Production of Interleukin 1 beta in primary, serum-free cultures of human osteoarthritic chondrocytes
Location
Philadelphia
Start Date
11-5-2016 1:00 PM
Description
Osteoarthritis (OA) is characterized by a loss of cartilage extracellular matrix (CEM) and an increase of cytokine production in the synovial joint. Notably, Interleukin-1 beta (IL-1β), elevated in OA cartilage, induces a number of responses from chondrocytes, including release and activation of matrix metalloproteases (MMPs). Enhanced degradation of the ECM, a hallmark of OA pathology, is likely due, in part, to increased cytokine production In this study, osteoarthritic chondrocytes isolated from total knee arthroplasty were reared in three-dimensional, serum-free, alginate cultures. The sides of least and greatest pathology of the femoral condyles and tibial plateaus were determined by gross inspection in the surgery suite and histological assessment. Medial and lateral cells isolated from femoral condyles and tibial plateaus were cultured separately. Chondrocytes were plated at 2.5x106 cells per ml of alginate and incubated in 2 mls of serum-free medium for five days. Conditioned media were collected on days 2 and 5 of culture, concentrated by centrifugation and IL-1β measured by immunoassay.IL-1β production was detected in medial and lateral chondrocyte cultures; however, the concentration of this cytokine was highest in the cultures established from the region of greatest pathology. Collagens type I and II degradation products were also increased in cultures of cells from the side of greatest pathology. These results demonstrate a correlation between elevated levels of IL-1 β, collagen degradation and extent of pathology in primary cultures that maintain the phenotype of human articular chondrocytes. This culture system provides a platform with which to further define the feedback loop between chondrocyte produced cytokines and MMPs in OA.
Production of Interleukin 1 beta in primary, serum-free cultures of human osteoarthritic chondrocytes
Philadelphia
Osteoarthritis (OA) is characterized by a loss of cartilage extracellular matrix (CEM) and an increase of cytokine production in the synovial joint. Notably, Interleukin-1 beta (IL-1β), elevated in OA cartilage, induces a number of responses from chondrocytes, including release and activation of matrix metalloproteases (MMPs). Enhanced degradation of the ECM, a hallmark of OA pathology, is likely due, in part, to increased cytokine production In this study, osteoarthritic chondrocytes isolated from total knee arthroplasty were reared in three-dimensional, serum-free, alginate cultures. The sides of least and greatest pathology of the femoral condyles and tibial plateaus were determined by gross inspection in the surgery suite and histological assessment. Medial and lateral cells isolated from femoral condyles and tibial plateaus were cultured separately. Chondrocytes were plated at 2.5x106 cells per ml of alginate and incubated in 2 mls of serum-free medium for five days. Conditioned media were collected on days 2 and 5 of culture, concentrated by centrifugation and IL-1β measured by immunoassay.IL-1β production was detected in medial and lateral chondrocyte cultures; however, the concentration of this cytokine was highest in the cultures established from the region of greatest pathology. Collagens type I and II degradation products were also increased in cultures of cells from the side of greatest pathology. These results demonstrate a correlation between elevated levels of IL-1 β, collagen degradation and extent of pathology in primary cultures that maintain the phenotype of human articular chondrocytes. This culture system provides a platform with which to further define the feedback loop between chondrocyte produced cytokines and MMPs in OA.