Promotion of type II collagen production (in vitro)
In the knee joint, "articular cartilage" at the edge of the femur and the tibia work as a cushion, and its main component type II collagen plays an important role. We studied what kind of effect CTP made on type II collagen synthesis.
Cell proliferative potential of cartilage cell (in vitro)
We studied involvement of CTP in proliferation of the cartilage cell.
1) Methods
Cartilage cells isolated from articular cartilages of cows were seeded in dishes at a concentration of 30 x 104 cells/cm2 and passaged 3 times. DMEM (GIBCO) + 20%FBS was applied as a control medium. In the CTP group, CTP of 30 μg/mL was added to the medium.
2) Results
There was little difference in cell proliferation between the control group and the CTP group. Therefore, we confirmed that CTP had no effect on a cell proliferation (Refer to the figure below).
Promotion of type II collagen production (in vitro)
We observed what kind of effect CTP had on type II collagen synthesis which played an important role in the cartilage. The cartilage cell usually receives some forces; the forces caused when the man is walking, or water pressure from the synovial fluid surrounding them. For simulating the above environment, we cultured cartilage cells under a condition of hydrostatic pressure loading, then studied the effect of CTP addition on extracellular matrix type II collagen synthesis.
1) Methods
Cartilage cells were applied a load of hydrostatic pressure by using a hydrostatic pressure loading device called SP-200T of Strex Inc. The schematic drawing is shown below. The device provided surface temperature of 37°C and pressure of 5 MPa to the chamber. After adding CTP-containing collagen of 30 μg/mL to the culture medium, the load of hydrostatic pressure of 5 MPa was applied at a frequency of 1.0 Hz for 12 hours, and we measured the expression amount of mRNA of extracellular matrix type II collagen by RT-PCR.
The schematic drawing of the hydrostatic pressure loading device
2) Results
Under the condition of hydrostatic pressure loading, the test result showed an increase of expression amount of mRNA of type II collagen according to the concentration of additional CTP.
3) Discussion
In cultivation of the cartilage cells under the condition of hydrostatic pressure loading, CTP addition had no impact on proliferation of the cultured cartilage cells, but promoted type II collagen production. Therefore, we can expect that ingestion of CTP-containing collagen promotes collagen production of the articular cartilage and it brings preventive/ healing effect against cartilage diseases such as knee osteoarthritis, and so on.
