Change in expression of tumor necrosis factor receptor-associated factor 6 in lung tissues of rats with pulmonary hypertension / 中华麻醉学杂志

ABSTRACT

Objective:To determine the change in the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6) in lung tissues of rats with pulmonary hypertension (PH).Methods:Sixteen SPF-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 200-220 g, were divided into 2 groups ( n=8 each) by the random number table method: control group (group C1) and PH group (group PH1). The model of PH was prepared by subcutaneous injection of monocrotaline. On day 28 after developing the model, the mean pulmonary arterial pressure (mPAP) was measured, and the Fulton index was calculated, and the percentage of media wall thickness of the small and medium pulmonary arteries and percentage of muscularized vessels were also calculated. The expression of TRAF6, transcription-3 (STAT3), phosphorylated STAT3 (p-STAT3) and Cyclin D1 in lung tissues was detected by Western blot, and p-STAT3/STAT3 ratio was calculated. The interaction between TRAF6 and STAT3 was determined by immunoprecipitation assay. Primarily cultured pulmonary artery smooth muscle cells of normal rats (group C2) and pulmonary artery smooth muscle cells of rats with PH (group PH2) were inoculated in 6-well plates ( n=3 each). The expression of TRAF6 mRNA was detected by quantitative polymerase chain reaction. The expression of TRAF6, STAT3, p-STAT3 and Cyclin D1 was detected by Western blot. Results:Compared with group C1, the mPAP, Fulton index, percentage of media wall thickness of the small and medium pulmonary arteries and percentage of muscularized vessels were significantly increased, the expression of TRAF6 and Cyclin D1 in lung tissues was up-regulated, the p-STAT3/STAT3 ratio was increased ( P<0.05 or 0.01), and the results of immunoprecipitation showed that TRAF6 interacted with STAT3 in group PH1. Compared with group C2, the expression of TRAF6 protein and mRNA and Cyclin D1 was significantly up-regulated, and the p-STAT3/STAT3 ratio was increased in group PH2 ( P<0.05 or 0.01). Conclusions:The expression of TRAF6 in the lung tissue is up-regulated in rats with PH, which may be related to pulmonary vascular remodeling by promoting the activation of STAT3.