MSC Therapy and Lubricin Replenishment

Background

Lubricin is a mucinous glycoprotein secreted in synovial joints that coats the articular surface and enables boundary lubrication between joint surfaces. Patients suffering from osteoarthritis experience severe pain due to deficiency of lubrication, which leads to progressive wear of cartilage. Therefore, replenishing lubricin may be a key aspect in addressing the challenges associated with osteoarthritis. 

One potential treatment for osteoarthritis is mesenchymal stem cell (MSC) therapy, a novel method aimed at stem cell-mediated repair of damaged cells. MSC therapy may increase the amount of lubricin in a joint. In a tissue engineered meniscus construct, MSCs were shown to be potent synthesizers of lubricin themselves. However, it has not been shown that MSCs added to the surface of native cartilage can aid in lubricin restoration. 

Aim

Determine the effect of IL-1β culture and seeding MSCs onto cartilage explants on lubricin distribution at the articular surface. 

Methods

Immunohistochemistry (IHC) was performed to detect lubricin on all samples. Afterwards, they were imaged on a brightfield microscope for qualitative analysis. The experimental groups are as follows: 

• Control: No IL-1β treatment nor MSC co-culture

• IL-1β: 10 ng/mL of IL-1β for 7 days

• MSC: MSC co-culture for 3 days

• IL-1β + MSC: 10 ng/mL of IL-1β for 7 days followed by MSC co-culture for 3 days

Results

The control group had the thickest band of lubricin. The MSC group had the second-thickest band, the IL-1β + MSC group third, and the IL-1β group fourth. Images from all four experimental groups had clearly visible chondrocytes embedded in the sample.

Significance

The control group and MSC group both had a greater amount of lubricin than the IL-1β and IL-1β + MSC groups. This indicated that IL-1β decreased lubricin production, which was the expected result and agreed with previous studies The IL-1β + MSC group having a greater amount of lubricin than the IL-1β group suggested that MSC therapy increased lubricin concentration. However, the sample size was still too small to draw conclusions on the effect of IL-1β treatment and MSC therapy on lubricin.