Regional Meniscal cell phenotypes in Osteoarthritic Tissues



Jingsong Wang, Sally Roberts, James Richardson, Karina Wright

Funded by the Orthopaedic Institute Ltd, Oswestry and China Scholarship Council

Menisci play an important role in force transmission, shock absorption, joint stability, lubrication and proprioception of the knee joint. Many studies suggest that meniscal degeneration plays a significant role in the pathology of osteoarthritis (OA). However, there is currently a lack of objective metrics to assess OA meniscal cell phenotypes.

We investigated the phenotypic markers and chondrogenic potency of avascular (white zone) and vascular (red zone) meniscal cells and chondrocytes from OA patients. Based on histology, we discovered that the transverse collagen bundle arranged in a “tree-like” formation within the meniscus appeared to have less blood vessels associated with them in the vascular region of the most degenerate menisci, which may indicate that such structures are involved in the pathological process (Figure 2).

We also found that the integrin family (CD49b, CD29) were expressed at a significantly higher level on avascular meniscal cells derived from tissues with a more degenerated inner border than non-degenerate menisci, suggesting that the integrin family may play an important role in meniscus OA pathology.

The illustration of “tree-like” transverse collagen fibre distribution (dotted line) in normal and degenerated meniscus. The “tree-like” structure was most disorganised and without blood vessels in the degenerated meniscus.