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Objective:To observe the expression of deleted in malignant brain tumor protein 1 (DMBT1) in rat acute respiratory distress syndrome (ARDS) model induced by sepsis and its relationship with ARDS related biomarkers.Methods:Forty-eight healthy male rats were randomly divided into sham operation group (Sham group) and ARDS model group, and the rats in each group were further divided into three subgroups at 6, 12 and 24 hours after operation, with 8 rats in each subgroup. The rats in the Sham group were exposed to the cecum only, and sepsis induced ARDS model was reproduced by cecal ligation and puncture (CLP) in the ARDS model group. The general performance was observed at 6, 12, 24 hours after operation. Abdominal aortic blood of rats was collected, and the levels of DMBT1, surfactant-associated protein D (SP-D), vascular endothelial growth factor (VEGF), interleukins (IL-6, IL-10) in serum were determined by enzyme-linked immunosorbent assay (ELISA). The lung tissues were collected, and the lung wet/dry weight (W/D) ratio was determined. The lung tissue pathological changes were observed under light microscope after hematoxylin-eosin (HE) staining, and the lung tissue injury score was evaluated. The expression of DMBT1 protein in lung tissue was determined by Western blotting. The relationship between the serum DMBT1 and SP-D, VEGF, IL-6, IL-10, lung tissue injury score were analyzed by Pearson correlation analysis.Results:Rats in the ARDS model group showed obvious pathological manifestations after operation. The alveolar structure destruction, inflammatory cell infiltration, and alveolar hemorrhage were observed under microscope. Compared with the Sham group, the lung tissue injury score and the lung W/D ratio at 12 hours after operation in the ARDS model group were significantly increased (lung tissue injury score: 3.35±0.13 vs. 1.16±0.07, lung W/D ratio: 5.36±0.44 vs. 4.38±0.35, both P < 0.05), and pulmonary edema was present, which suggested that the ARDS model caused by CLP was successfully reproduced. The results of ELISA and Western blotting showed that the levels of serum DMBT1, SP-D, VEGF and IL-6 in the ARDS model group increased gradually with time, while the level of IL-10 increased first and then decreased. Compared with the Sham group, the levels of DMBT1 in serum and the expressions of DMBT1 protein in lung tissue in the ARDS model group were significantly increased from 6 hours after operation [serum (ng/L) : 231.96±19.17 vs. 187.44±10.19, lung tissue (DMBT1/β-actin): 2.05±0.19 vs. 0.93±0.25, both P < 0.05], and the levels of SP-D, VEGF, IL-6 and IL-10 in serum were significantly increased from 12 hours after operation [SP-D (ng/L): 73.35±8.05 vs. 43.28±5.77, VEGF (ng/L): 89.85±8.47 vs. 43.19±5.11, IL-6 (ng/L): 36.01±2.48 vs. 17.49±1.77, IL-10 (ng/L): 84.55±8.41 vs. 39.83±5.02, all P < 0.05]. Pearson correlation analysis showed that serum DMBT1 was positively correlated with serum SP-D, VEGF, IL-6, IL-10 and lung injury score at 12 hours and 24 hours in the ARDS model group (12 hours: r values were 0.946, 0.942, 0.931, 0.936, 0.748, respectively; 24 hours: r values were 0.892, 0.945, 0.951, 0.918, 0.973, respectively; all P < 0.05). Conclusion:DMBT1 is a novel early biomarker of ARDS by affecting alveolar epithelial cell, alveolar capillary permeability and inflammatory response.
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Objective To evaluate the value of bedside lung ultrasound for diagnosis of acute re-spiratory distress syndrome ( ARDS) and for assessment of the severity. Methods Fifty patients of both se-xes suspected of having ARDS ( oxygenation index＜300 mmHg) and required lung CT tests and Pulse Indi-cator Continuous Cardiac Output because of their condition, aged 18-80 yr, were selected. At 24 h after entering ICU, chest CT, lung ultrasound and arterial blood gas analysis were performed to record Extravas-cular Lung Water Index ( EVLWI) and the number of B lines, and lung injury ultrasound score and oxygen-ation index were calculated. The patients diagnosed with ARDS by chest CT and lung ultrasound were divid-ed into 3 groups: mild group ( 200 mmHg＜oxygenation index≤300 mmHg) , moderate group ( 100 mmHg＜oxygenation index≤200 mmHg) and severe group ( oxygenation index≤100 mmHg) . Kappa consistency a-nalysis was used to assess the consistency between lung ultrasound and chest CT in diagnosis of ARDS. The receiver operating characteristic curves of th number of B lines, EVLWI and lung injury ultrasound score in assessing the severity of ARDS were drawn, and the area under the curve and 95％ confidence interval ( CI) , critical value, sensitivity and specificity were calculated. Results Forty-six patients were diag-nosed as having ARDS by both chest CT and lung ultrasound. There was good consistency ( Kappa value 0. 648, P＜0. 01) between chest CT and lung ultrasound in diagnosis of ARDS. There was good consistency ( Kappa value 0. 788, P＜0. 01) between lung ultrasound and chest CT in diagnosis of pulmonary consolida-tion. Lung ultrasound and chest CT were in good agreement ( Kappa value 0. 825, P＜0. 01) with each oth-er in diagnosis of pulmonary consolidation in the posterior region. Compared with mild group, the lung inju-ry ultrasound score was significantly increased, and the number of B lines was increased in moderate group, and the lung injury ultrasound score and EVLWI were significantly increased, and the number of B lines was increased in severe group ( P＜0. 05) . Compared with moderate group, the lung injury ultrasound score and EVLWI were significantly increased, and the number of B lines was increased in severe group ( P＜0. 05) . The area under the curve ( 95％ CI ) of the number of B lines in diagnosing severe ARDS was 0. 915 ( 0. 905-0. 935 ) , and the critical value, sensitivity and specificity were 15. 5, 78. 9％ and 85. 2％, respectively. The area under the curve ( 95％ CI) of lung injury ultrasound score in diagnosing severe ARDS was 0. 856 (0. 833-0. 878), and the critical value, sensitivity and specificity were 25. 5, 73. 7％ and 82. 5％, respectively. The area under the curve (95％ CI) of EVLWI in diagnosing severe ARDS was 0. 907 ( 0. 888-0. 933) , and the critical value, sensitivity and specificity were 15. 5, 73. 7％and 92. 6％, respectively. Conclusion Lung ultrasound can be used for diagnosis of ARDS and for evalu-ation of the severity of ARDS.
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Objective To observe the effects of hydrogen sulfide (H2S) on structure and function of mitochondria of lung in rats with acute lung injury (ALI) induced by lipopolysaccharide (LPS).Methods Forty healthy male Sprague-Dawley (SD) rats were randomly divided into control group, LPS injury group, and low-, middle-, and high-dose NaHS groups, with 8 rats in each group. The rats in LPS injury group were given LPS 5 mg/kg via sublingual vein, and those in low-, middle-, and high-dose NaHS groups were challenged by LPS for 3 hours followed by intraperitoneally injection of 0.78, 1.56 and 3.12 mg/kg NaHS respectively in a volume of 2 mL/kg. The rats in control group were given 2 mL/kg normal saline via sublingual vein. The rats were sacrificed at 6 hours after model reproduction, and the lung tissues were harvested on time. The mitochondria in lung tissues were isolated with differential centrifugation. The lung mitochondria ultra structures were observed with electron microscope. The content ofmalondialdehyde (MDA) in mitochondria was determined with thiobarbituric acid method, and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and adenosine triphosphatase (ATPase) were determined with xanthine oxidase method. The mitochondrial activity and swelling were determined by multiskan spectrum.Results It was shown by transmission electron microscope that the mitochondrial structure in the control group was normal. The mitochondria in rat lung cells was swollen with disrupted or disintegrated cristae, the osmiophilic lamellar bodies had fused or disappeared, and rough endoplasmic reticulum degranulation phenomenon was obvious in LPS injury group. The mitochondrial damage was slightly mitigated in the low-dose NaHS group, and it was significantly mitigated in the middle-dose and high-dose NaHS groups. Compared with control group, the MDA content in lung mitochondria in LPS injury group was significantly increased (nmol/mg: 26.30±1.45 vs. 11.16±1.20), andSOD, GSH-Px, and ATPase activities were significantly decreased [SOD (U/mg): 18.78±1.13 vs. 27.44±1.97, GSH-Px (U/mg): 63.91±1.99 vs. 128.15±3.47, ATPase (U/mg): 4.83±0.25 vs. 9.92±0.65]; as well as the activity of the mitochondria was significantly decreased (A value: 0.164±0.025 vs. 0.319±0.045), and the swelling of the mitochondria was significantly increased (A value: 0.182±0.012 vs. 0.273±0.023), all with significantly statistical differences (allP < 0.01). Compared with LPS injury group, the MDA contents in low-, middle-, and high-dose NaHS groups were significantly decreased (nmol/mg: 21.89±1.23, 17.63±1.56, 12.19±1.30 vs. 26.30±1.45), and the SOD, GSH-PX, and ATPase activities were significantly increased [SOD (U/mg): 20.13±0.85, 21.38±1.22, 24.05±1.56 vs. 18.78±1.13; GSH-Px (U/mg): 82.06±1.65, 101.45±2.14, 117.80±2.12 vs. 63.91±1.99; ATPase (U/mg): 5.34±0.23, 7.06±0.37, 8.78±0.44 vs. 4.83±0.25]; as well as the activity of the mitochondria was markedly increased (A value: 0.194±0.018, 0.230±0.032, 0.297±0.038 vs. 0.164±0.025), and the swelling of mitochondria was markedly decreased (A value: 0.195±0.008, 0.219±0.017, 0.249±0.018 vs. 0.182±0.012), all with significantly statistical differences (allP < 0.05). Moreover, the protective effect of NaHS showed a dose-dependent manner.Conclusion It could be concluded that LPS induce mitochondrial structural damage and functional impairment in rats with ALI induced by LPS, and H2S have a beneficial effect against ALI induced by LPS with decreasing the mitochondrial lipid peroxidation level and protecting the cell structure and function, and the effect is correlated with the dosage.
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Objective To evaluate the effect of exogenous hydrogen sulfide (H2S) on mitochondrion-dependent apoptosis in lung tissues of rats with endotoxemia.Methods Forty healthy male SpragueDawley rats,aged 2-3 months,weighing 250-310 g,were divided into 5 groups (n=8 each) using a random number table:control group (group C),lipopolysaccharide (LPS) group,low dose sodium hydrosulphide (NaHS) group (group L-NaHS),moderate dose NaHS group (group M-NaHS) and high dose NaHS group (group H-NaHS).Endotoxemia was induced by Ⅳ LPS 5 mg/kg in chloral hydrate-anesthetized rats.The equal volume of 0.9％ sodium chloride solution was intravenously injected in group C.NaHS (an exogenous donor of H2S) 0.78,1.56 and 3.12 mg/kg were intraperitoneally injected at 3 h after LPS injection in L-NaHS,M-NaHS and H-NaHS groups,respectively.The rats were sacrificed at 6 h after injection of LPS or 0.9％ sodium chloride solution,and lungs were removed for examination of the mitochondrial ultrastructure of lung tissues and for determination of apoptosis in lung cells (by flow cytometry) and expression of caspase-3,caspase-9,Bcl-2 and Bax protein and mRNA in lung tissues (by Western blot or real-timne polymerase chain reaction).The apoptosis rate and ratio of Bcl-2 expression to Bax expression (Bcl-2/Bax ratio) were calculated.The expression of cytochrome c (Cyt c) in cytoplasm and mitochondria of lung tissues was detected by Western blot.Results The apoptosis rate was significantly increased,the expression of caspase-3,caspase-9,Bcl-2 and Bax protein and mRNA was up-regulated,Bcl-2/Bax ratio was decreased,the expression of Cyt c in cytoplasm was up-regulated,and the expression of Cyt c in mitochondria was down-regulated in group LPS (P ＜0.05 or 0.01).Compared with group LPS,the apoptosis rate was significantly decreased,the expression of caspase-3 and Bax protein and mRNA was down-regulated,the expression of Bcl-2 protein and mRNA was up-regulated,Bcl-2/Bax ratio was increased,the expression of Cyt c in cytoplasm was down-regulated,and the expression of Cyt c in mitochondria was up-regulated in L-NaHS,M-NaHS and H-NaHS groups,the expression of caspase-9 protein and mRNA was significantly down-regulated in M-NaHS and H-NaHS groups,and the expression of caspase-9 was significantly down-regulated (P ＜0.05 or 0.01),and no significant change was found in caspase-9 mRNA expression in group L-NaHS (P＞0.05),and the damage to mitochondrial ultrastructure was significantly mitigated in MNaHS and H-NaHS groups.Conclusion The mechanism by which exogenous H2S inhibits cell apoptosis in lung tissues may be related to inhibition of mitochondrion-dependent apoptosis in rats with endotoxemia.