Effects of hydrogen-rich saline on acute lung injury in rats with traumatic brain injury and role of Nrf2/HO-1 signaling pathway / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effects of hydrogen-rich saline on acute lung injury in rats with traumatic brain injury (TBI) and the role of nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1 (HO-1) signaling pathway.Methods:Forty-eight adult male Sprague-Dawley rats, weighing 220-250 g, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (S group), TBI group (T group), TBI plus hydrogen-rich saline group (T+ H group), and TBI plus hydrogen-rich saline plus brusatol group (T+ H+ B group). TBI model was developed by controlled cortical impact.Nrf2 inhibitor brusatol 0.4 mg/kg was intraperitoneally injected every other day starting from 10 days before development of TBI model in T+ H+ B group.Hydrogen-rich fluid 10 ml/kg was intraperitoneally injected at 1 and 6 h after development of TBI model in T+ H group and T+ H+ B group.At 24 h after development of TBI model, the bronchoalveolar lavage fluid (BALF) was collected to detect the concentration of protein, blood samples from the right common carotid artery were collected and lung tissues were obtained for determination of the levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10) and high-mobility group box 1 protein (HMGB1) in serum and lung tissues (by enzyme-linked immunosorbent assay), wet to dry lung weight ratio (W/D ratio), expression of nuclear-Nrf2, total-Nrf2 and HO-1 in lung tissues (by Western blot), and expression of HO-1 mRNA (by real-time polymerase chain reaction) and for microscopic examination of histopathologic changes (by haematoxylin and eosin staining) which were scored. Results:Compared with S group, the concentrations of protein in BALF, W/D ratio of lung tissues and lung injury score were significantly increased, the levels of TNF-α, HMGB1 and IL-10 in serum and lung tissues were increased, and the expression of nuclear Nrf2, total Nrf2 and HO-1 protein and mRNA in lung tissues was up-regulated in T and T+ H groups ( P<0.05). Compared with T group, the concentrations of protein in BALF, W/D ratio of lung tissues and lung injury score were significantly decreased, the levels of TNF-α and HMGB1 in serum and lung tissues were decreased, the level of IL-10 in serum and lung tissues was increased, and the expression of nuclear Nrf2, total Nrf2 and HO-1 protein and mRNA in lung tissues was up-regulated in T+ H group ( P<0.05), and no significant changes were found in the parameters mentioned above in T+ H+ B group ( P>0.05). Compared with T+ H group, the concentrations of protein in BALF, W/D ratio of lung tissues and lung injury score were significantly increased, the levels of TNF-α and HMGB1 in serum and lung tissues were increased, the level of IL-10 in serum and lung tissues was decreased, and the expression of nuclear Nrf2, total Nrf2 and HO-1 protein and mRNA in lung tissues was down-regulated in T+ H+ B group ( P<0.05). Conclusions:Hydrogen-rich solution can alleviate acute lung injury in rats with traumatic brain injury, and the mechanism is related to activation of Nrf2/HO-1 signaling pathway and inhibition of the inflammatory responses.