[Animal experiment]-The proliferation of umbilical cord mesenchymal stem cells on dairy cow mammary epithelial cells under serum-free co-culture conditions

  Purpose: To investigate the proliferation of umbilical cord mesenchymal stem cells (UC-MSCs) on bovine mammary gland epithelial cells (BMECs) under serum-free co-culture conditions.

  Methods: Select the best growing UC-MSCs and BMECs. The two types of cells were co-cultured with direct contact and indirect contact as the experimental group. The direct contact was based on UC-MSCs: BMECs were 2:1, 1: 1, 1:2, 1:3, 1:4, 1:5, 1:10 concentration gradient mixed co-culture, indirect contact is to extract the supernatant of UC-MSCs as a conditioned medium to resuspend BMECs, the control group UC-MSCs and BMECs were cultured alone, and a negative blank control was set. The growth changes of cells in each group were observed at 0, 4, 8, 12, 24, 36, 48, 60, 72 h, and the CCK-8 method was used to detect Cell proliferation in each group.

  Results: At 48 h, the A value of the conditioned medium BMECs group was significantly higher than that of the control group (P<0.05), while the A value of the 1:2 concentration group reached the peak, which was extremely significantly higher than that of the control group (P<0.01). Other concentration groups and conditioned medium BMECs group (P<0.05).

  Conclusion: Under serum-free conditions, the co-culture of UC-MSCs and BMECs can promote the proliferation of BMECs. The proliferation effect of direct contact is better than that of indirect contact. The optimal ratio is 1:2, and the optimal time is 48 hours.