Expression of PCNA,IL-6,IL-11 and galectin-3 in human umbilical cord mesenchymal stem cells during long-term culture

AIM: To investigate the changes of the mRNA and protein levels of proliferating cell nuclear antigen(PCNA),interleukin-6(IL-6),IL-11 and galectin-3 in human umbilical cord mesenchymal stem cells (hUC-MSCs) during long-term culture in vitro. METHODS: Human umbilical cords from neonates via caesarean section were collected, and the hUC-MSCs were isolated and sub-cultured. The cells and culture supernatants at passages 3, 8, 18, 28 and 33 were collected. The mRNA expression and protein secretion of PCNA,IL-6,IL-11 and galectin-3 in different passages of hUC-MSCs were detected by qRT-PCR, ELISA, and Western blotting. RESULTS: The mRNA expression of PCNA,IL-6 and IL-11 and protein secretion of IL-6 and IL-11 reduced gradually along with the passage.Comparing the 33rd passage with the 3rd passage of MSCs, the mRNA expression of PCNA,IL-6 and IL-11 decreased by 33%, 56% and 37%, and the protein secretion decreased by 50.3% and 58.9%, respectively. The differences were statistically significant (P<0.01). No statistically significant difference of galectin-3 mRNA expression and the protein band brightness (P>0.05) in the MSCs among different passages was observed. CONCLUSION: The multiplication and haematogenesis support capabilities of the might decrease or even lose during long-term culture in vitro. Long-term culture might have no effect on hUC-MSCs immunoregulatory capability of hUC-MSCs, which requires further study.