Impacts of K562 cells towards activities of Toll-like receptor pathway of human mesenchymal stem cell-bone marrow.

The study aim was to investigate the impacts of K562 cells towards the activities of Toll-like receptor pathway of human mesenchymal stem cell-bone marrow (HMSC-bm). The in vitro co-culture of HMSC-bm and K562 cells was set as the experiment group (HMSC-bm + K562), the HMSC-bm cultured alone was set as the control group (HMSC-bm), the expressions of six interested genes and their proteins, namely MyD88, P38, NF-κB, TAB1, TLR3 and TBK1, of the Toll -like receptor signaling pathway were detected and compared, as well as the secretions of such cytokines as IL-6, IL-8, TNF-α and IFN-α in the cell supernatant, which were regulated by the Toll-like receptor pathway. The expressions of MyD88, P38, TAB1 and TLR3 of the HMSC-bm + K562 group were higher than the HMSC-bm group, while that of TBK1 was lower, and the NF-κB expression showed no significant difference between the two groups (P > 0.05). Compared with the HMSC-bm group, the supernatant of HMSC-bm + K562 group exhibited the higher secretion levels of IL-6 and IL-8, while that of IFN-α was just contrary, and the differences were significant (P < 0.05). The secretion levels of TNF-α within the two groups were not significantly different (P > 0.05). The co-culture of K562 and HMSC-bm could induce the activity changes of Toll-like receptor pathway of HMSC-bm, which was beneficial towards the proliferation of K562 cells.