Mouse synovial mesenchymal stem cells increase in yield with knee inflammation

Area of Science:

• Biomedical Engineering
• Stem Cell Biology
• Musculoskeletal Research

Background:

• Mesenchymal stem cells (MSCs) are crucial for tissue regeneration.
• Harvesting sufficient MSCs from mouse synovium is challenging for research.
• Inflammation's effect on synovial MSC yield in mice is not well understood.

Purpose of the Study:

• To determine if induced synovitis increases the yield of synovial mesenchymal stem cells (MSCs) from mouse infrapatellar fat pads (IFPs).
• To characterize the harvested cells and assess the relationship between inflammation severity and cell yield.

Main Methods:

• Infrapatellar fat pads (IFPs) were harvested from mouse knees at 3, 7, and 14 days post-carrageenan injection.
• Control group consisted of IFPs from untreated knees.
• Cell yield, multipotency, surface epitopes, and synovitis severity (histology) were analyzed.

Main Results:

• A significant 50-fold increase in cell yield was observed in the 3- and 7-day post-treatment groups compared to controls.
• Harvested cells exhibited characteristics of MSCs.
• Increased cell yield correlated with higher synovitis scores.

Conclusions:

• Induced synovitis in mice effectively increases the yield of synovial MSCs from IFPs.
• This method facilitates the study of molecular mechanisms underlying cartilage regeneration using synovial MSCs in mouse models.