Abstract:

Objective To investigate the regulation of aquaporin 1 (AQP1) expression in rat pulmonary microvascular endothelial cells (PMVECs) by free fatty acid (FFA) mixture and action mechanism. Methods Western blotting was used to detect changes in AQP1 protein expression in rat PMVECs after FFA treatment for different periods. Western blotting and real-time PCR were used to detect changes in AQP1 protein and mRNA expressions in rat PMVECs after being treated with FFA at different concentrations. The effect of FFA treatment on AQP1 expression was detected by Western blotting after p38 MAPK pathway had been suppressed by SB203580. Results AQP1 protein expressions in RAT PMVECs after being treated with FFA for 6 and 12 h were significantly higher than those in the blank control group (P=0.000,P=0.003). AQP1 protein expressions in 200 μmol/L and 500μmol/L FFA groups were significantly higher than those in the blank control group (P=0.007, P=0.002). AQP1 mRNA expressions in 100 μmol/L, 200 μmol/L and 500μmol/L FFA groups were significantly higher than those in the blank control group (P=0.000). SB203580 pretreatment could suppress FFA-induced increase in AQP1 protein expression in rat PMVECs (P=0.016). Conclusion FFA can up-regulate AQP1 expression and affect AQP1-mediated intrapulmonary water transport progress in fat embolisms to a certain extent. The regulation mechanism may be associated with activation of p38 MAPK signaling pathway.

Key words: fat embolism syndrome, lung edema, free fatty acid, aquaporin 1, rat pulmonary microvascular endothelial cells；p38 MAPK signaling pathway