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Objective To investigate both in mechanism of hyperoxia-induced acute lung injury (HALI) by vivo experiment,to observe the Bruton' s tyrosine kinase (Btk) and nuclear factor kappa B (NF-κB) signals expression level.Methods Total of 72 healthy male Kunming mice were randomly (random number) divided into four groups:air control group,hyperoxia exposure 3 days group (H3d group),hyperoxia exposure 3 days + inhibitor group (H3d + Ⅰ group) and inhibitor groups.Then the pathological changes of lung tissues were observed under light microscope;The total protein content (TP) of bronchoalveolar lavage fluid (BALF) and wet/dry weight ratio (W/D) of lung were detected;The protein expression of Btk,p-Btk,pNF-κB p65 were mersured by Western blot;tlhe mRNA level of IL-6 was determined by real-time polymerase chain reaction (qRT-PCR);the level of monocyte chemoattractant protein-1 (MCP-1) in serum was detected by enzyme-linked immunosorbent assay (ELISA).Statistcal significance was determined by 1-way ANOVA.Results There were no significant difference in the data between the control group and the inhibitor group (P ＞ 0.05).The pathological injury in light microscope,content of total protein in BALF,W/D ratio of lung tissues in H3d group were significantly higher than H3d + Ⅰ group (Respectively P =O.002,P =0.000).Western blot analysis showed that expression of Btk,p-Btk,pNF-κB p65 in H3d group were significantly higher than those in H3d + Ⅰ group (Respectively P =0.002,P =0.013,P =0.000).RT-qPCR results showed that the expression of IL-6 mRNA in H3d group were significantly higher than control group (P =0.004),inhibitor group (P =0.000) and H3d + Ⅰ group (P =0.021).In addition,The serum MCP-1 levels in H3d group were higher markely than the control group (P =0.002),inhibitor group (P =0.000) and H3d + Ⅰ group (P =0.009).The correlation analysis showed that pNF-κB p65 were positively correlated wiht Btk and p-Btk (r =0.902 and 0.954,P ＜ 0.01).Conclusions Btk may trigger the release of IL-6 and MCP-1 by mediating the signaling pathway of NF-κB in vivo study,which was most important in the occurrence of HALI.Therefore,inhibiting the Btk activity would alleviate the severity of lung injury effectively.
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Objective To explore the effect of therapeutic hypothermia on the activation of inflammasome in the lung tissue of rats with hemorrhagic shock (HS).Methods Twenty-four male Sprague-Dawley rats were randomly (random number) divided into three groups:sham group,normothermia resuscitation (NR) group and hypothermia resuscitation (HR) group.Rats of each group were subjected to pressure-controlled (MAP 40 mmHg) HS for 1 h,then the NR group and the HR group were resuscitated with lactated Ringer and MAP was maintained at 90 mmHg for 1 h.Four hours later,the rats in each group were sacrificed by exsanguination.Hematoxylin eosin staining was used to observe the injury of lung tissue.The desiccation method was used to detect the edema of lung tissue.RT-PCR and western blot were employed to evaluate the mRNA and protein expression of NLRP-3,IL-1β,caspase-1.Analysis of variance was used for comparison among groups,and SNK-q test was used for comparison between two groups.Results (1) The injury of lung tissue in HR group was significantly milder than that in NR group;(2) Wet/dry (W/D) weight ratio of lung in HR group decrease compared with NR group [HR group 5.85 ± 0.102;NR group 6.471 ± 0.165 8 (t =3.14,P ＜ 0.05)];(3) NLRP-3 and of Caspase-1 protein expression in the HR group were lower than those in NR group.(4) The NLRP-3 mRNA expression in HR group was lower compared with NR group [(HR group 1.027 ± 0.143;NR group 1.3487 ± 0.163 (t =4.36,P ＜ 0.05)] and IL-1 mRNA expression in HR group was lower compared with NR group [HR group 162.3 ± 0.125;NR group 2.388 ± 0.229 (t =7.72,P ＜ 0.05)].Conclusions Therapeutic hypothermia attenuated ALI induced by HS in rats by modulation of signal way of inflammasome.
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Objective To investigate the effects of microRNA-21-5p (miR-21-5p) on hyperoxic acute lung injury (HALI) in rats and provide a theoretical basis for HALI gene therapy. Methods One hundred and sixty Sprague-Dawley (SD) rats were randomly divided into four groups with number table:hyperoxia control group, phosphate buffer saline (PBS) group, blank virus group and miRNA-21-5p group (each, n = 40). The rats in hyperoxia control group were fed directly in the hyperoxia box (oxygen concentration > 90%); in the other three groups, 200 μL PBS, 200μL slow virus and 200μL miRNA-21-5p slow virus were dropped into the nose respectively, and then they were fed in the hyperoxia box. The rats were exposed to hyperoxia in the boxes for 0, 24, 48 and 72 hours in all the groups, and at each time point, 10 rats were taken randomly from each group to perform arterial blood-gas analysis, calculate oxygenation index (OI) and respiratory index (RI). Afterwards the rats were sacrificed by blood-letting from carotid artery under intra-peritoneal anesthesia, and the lung tissues were obtained to measure the left lung wet/dry weight (W/D) ratio, hemotoxylin-eosin (HE) staining was made and the pathological changes of the right lung were observed under light microscope and the pathological score was measured. Results At 0 hour, the OI, RI, lung W/D ratio and the lung tissue pathology score in rats with hyperoxic injury had no statistically significant differences among the four groups (all P>0.05). With the extension of time, the level of OI was gradually reduced, and the levels of RI, pathologic score and W/D ratio of lung tissues were gradually increased. Compared with the hyperoxia control group, in miRNA-21-5p group, the levels of OI were increased significantly at 24, 48 and 72 hours after the exposure to hyperoxia [mmHg (1 mmHg = 0.133 kPa): 24 hours 358.10±29.25 vs. 306.19±37.23, 48 hours 336.67±29.27 vs. 269.70±29.00, 72 hours 323.81±19.05 vs. 203.81±43.40, all P 0.05). Under the optical microscope, along with the prolongation of exposure to hyperoxia, the structure of alveoli was gradually disturbed, their walls fractured and damaged, alveolar septa widened, edematous, infiltrated with inflammatory cells and in part of the rats a small amount of red blood cell exudates could be seen, but the degree of lung pathological injury in miRNA-21-5p group was much milder than that of the other groups. Conclusion The rat persistently exposed to hyperoxia for 24 hours can establish the rat model of HALI successfully, and the miRNA-21-5p can protect the lung tissue from the damage to some degrees in HALI rats.
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Objective To investigate the effect of ischemic post-conditioning (IPO) on the level of Heme oxygenase-1 (HO-1) in acute ischemia - reperfusion (I/R) injury of lung in order to illuminate its protective mechanism.Methods Forty-eight adult SD rats were randomly divided (random number) into 6groups ( n =8 each):sham operation group ( S group) ; I/R group in which the hilum of left lung was clamped for 45 min followed by 105 min reperfusion; IPO group in which left lung hilum was clamped for 45min and post - conditioned by alternation of 30 s reperfusion with 30 s re-occlusion for three times before perfect perfusion for 102 min; Hemin (HM) + I/R group; ZnPPⅨ (zinc protoporphyrin Ⅸ) + IPO group and HM + S group.Arterial partial pressure of oxygen ( PaO2 ) and malondialdehyde (MDA) content in blood serum were assayed.The left lung was removed for determination of wet/dry (W/D) lung weight ratio and level of HO-1 protein was detected by immunohistochemical technique and pathohistological changes were observed under light microscopic examination. Comparisons among multiple groups were studied by using one-way analysis of variance (ANOVA). Statistical comparisons within groups were analyzed by using paired t -test.Results The level of HO-1 in lung tissue was significantly increased in the I/R group compared with the S group and the HM + S group (P ＜0.01,P ＜0.05).Compared to the I/R group,the IPO and the HM + I/R groups had significant higher level of HO-1 ( P ＜ 0.05,P ＜ 0.01 ).The PaO2 was significantly lower in all experimental groups than that in the S group (90 ± 11 ) mmHg.However,the values of PaO2 in the IPO and the HM + I/R groups were higher than that in the I/R group (P ＜ 0.01 ).In addition to severe lung tissue damage evidenced by pathohistological changes,the lung wet/dry (W/D) weight ratio and MDA level in blood serum were significantly higher in the I/R group than those in the S group (P ＜0.01 ),whereas the lung damage was attenuated either by IPO or by HM pretreatment (P ＜ 0.05,IPO or HM + I/R vs.I/R).Conclusions IPO can attenuate the lung ischemia - reperfusion injury through upregulating the level of HO-1 protein and inhibiting lipid peroxidation injury.