Lubricin expression in the lumbar endplate and its association with Modic changes

Area of Science:

• Biochemistry
• Cell Biology
• Orthopedics

Background:

• Modic changes (MCs) are common findings in the lumbar spine.
• The role of lubricin in endplate health and Modic changes is not fully understood.

Purpose of the Study:

• To investigate lubricin expression in human lumbar endplates.
• To determine the association between lubricin and Modic changes.
• To explore the effect of Propionibacteria acnes on lubricin expression and endplate degeneration.

Main Methods:

• Immunohistochemistry and quantitative polymerase chain reaction (qPCR) were used to analyze lubricin expression in human and rabbit endplate specimens.
• A rabbit model was utilized to study Modic changes and endplate degeneration.
• Rabbit endplate chondrocytes were co-cultured with P. acnes supernatant to evaluate gene expression.

Main Results:

• Lubricin expression was lower in human lumbar endplates with Modic changes compared to normal endplates.
• P. acnes infection in rabbits led to decreased lubricin expression and endplate degeneration.
• P. acnes supernatant reduced lubricin, aggrecan, sox9, and collagen type-II expression while increasing MMP-1 and ADAMTS5 in cultured chondrocytes.
• Lubricin overexpression downregulated MMP-1, ADAMTS5, IL-1β, and IL-6 expression.

Conclusions:

• Lubricin is present in the lumbar endplate and may possess anti-inflammatory properties.
• P. acnes infection inhibits lubricin expression in cartilage endplate cells, potentially contributing to Modic changes and endplate degeneration.