Expression of cartilage glycoprotein 39 in peripheral blood monocytes of septic rat and its role in TLR 4-NF-κB signaling pathways.

Objective: To investigate Cartilage glycoprotein 39 (Cgp-39) expression in peripheral blood monocytes of septic rats, and analyze the relationship between Toll-like receptor 4 (TLR4)-NF-κB signalling pathway and Cgp-39 expression.

Methods: The ligation puncture was performed to establish rat sepsis model, and ELISA was used to measure serum Cgp-39 concentration. Peripheral blood mononuclear cells was isolated and cultured for 72 h. RNA interference technology was used to inhibit TLR4 and NF-κB gene expression, and real-time PCR and Western blot were performed to detect mRNA and protein expression of TLR4 and NF-κB.

Results: At 1 h, there was no significant differences in serum Cgp-39 concentration between sepsis group and the control group (P > 0.05), however, at 6 h, 12 h, 24 h and 48 h, serum Cgp-39 concentrations in sepsis group were significantly higher than those in the control group at the corresponding time points (P < 0.05). Compared with the control group, TLR4 mRNA and protein expression were increased significantly in sepsis group and sepsis NF-κB interference group; NF-κB mRNA and protein expression were increased significantly in sepsis group and sepsis TLR4 interference group. However, compared with sepsis group, Cgp-39 concentrations decreased significantly in either sepsis TLR4 interference group or NF-κB interference group (P < 0.05 for both).

Conclusion: Cgp-39 is highly expressed in peripheral blood monocytes of septic rat and TLR4-NF-κB signalling pathways may be involved in the regulation of Cgp-39 expression.