apoptosis
To explore whether C1QTNF6 in leukocytes affects hypoxia-induced BBB disruption through an inflammatory response, we established an in vitro model in which OGD-exposed hCMEC/D3 cells were co-cultured with HL-60 cells. HL-60 cells in the different groups were treated as aforementioned. Flow cytometry analysis revealed a decreased apoptosis ratio in hCMEC/D3 cells in the OGD+H19 siRNA-HL-60 group than in the OGD+control-HL-60 group (Figure 6A, B, P < 0.05). However, there was an increased apoptosis ratio in hCMEC/D3 cells in the OGD+miR-29b antagomir-HL-60 group than in the OGD+control-HL-60 group (Figure 6A, B, P < 0.05). However, the increased hCMEC/D3 cell apoptosis induced by OGD+miR-29b antagomir-HL-60 was reversed by H19 siRNA treatment (Figure 6A, B, P < 0.05).
Additionally, we measured C1QTNF6, IL-1β, and TNF-α expression in HL-60 cells and ZO-1 and occludin expression in hCMEC/D3 cells. Treatment with miR-29b antagomir significantly increased C1QTNF6, IL-1β, and TNF-α expression in HL-60 cells (Figure 6C, P < 0.05). There was a significant decrease in C1QTNF6, IL-1β, and TNF-α expression in HL-60 cells treated with H19 siRNA than in OGD HL-60 cells (Figure 6C,P < 0.05). Furthermore, we observed changes in ZO-1 and occludin levels in hCMEC/D3 cells, as well changes in C1QTNF6, IL-1β, and TNF-α expression in HL-60 cells. (Figure 6C). These findings suggest that H19 in leukocytes aggravates hypoxia-induced hCMEC/D3 apoptosis by targeting miR-29b/C1QTNF6.