Objective To investigate the effect of non-coding RNA activated by DNA damage (NORAD) on acute lung injury (ALI) in septic rats by regulating the miR-155-5p/TLR6 molecular axis. Methods The rats were randomly divided into control group, model group, low NORAD expression no-load group (LV-sh-NC), low NORAD expression group (LV-sh-NORAD), low NORAD expression +miR-155-5p low expression no-load group (LV-sh-NORAD+NC antagomir), NORAD low expression +miR-155-5p low expression group (LV-sh-NORAD+miR-155-5p antagomir). ELISA kits were applied to detect interleukin (IL)-8, IL-1β, and tumor necrosis factor-α (TNF-α) levels; quantitative real-time polymerase chain reaction was applied to detect the expression of NORAD, miR-155-5p, and Toll-like receptor 6 (TLR6) genes in lung tissue of rats in each group. The ratio of wet weight to dry weight (W/D) of lung tissue was measured. The pathological changes of lung tissue were observed by hematoxylin-eosin staining, and apoptosis in lung tissue cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling. Western blot was applied to detect the expressions of TLR6, Bax, Bcl-2, and cleaved cysteinyl aspartate specific proteinase 3 caspase-3) proteins in cells. Dual luciferase reporter gene experiment was applied to verify the relationship between miR-155-5p and NORAD and TLR6. Results Compared with the control group, the lung tissue of rats in the model group and LV-sh-NC group was obviously damaged, the levels of serum IL-1β, TNF-α, IL-8, expression of NORAD and TLR6 mRNA in lung tissue, W/D ratio, apoptosis rate, expression of TLR6, Bax, and Cleaved-caspase-3 proteins were obviously increased, the expression of miR-155-5p and Bcl-2 proteins in lung tissue was obviously reduced (P<0.05). Down-regulation of NORAD expression could reduce lung tissue injury, serum IL-1β, TNF-α, IL-8 levels, mRNA expression of NORAD and TLR6 in lung tissue, W/D ratio, apoptosis rate, TLR6, Bax, Cleaved caspase-3 protein expression, and cleaved caspase-3 protein expression. The expression of miR-155-5p and Bcl-2 protein in lung tissue were significantly increased (P<0.05). Down-regulating the expression of miR-155-5p could reduce the improvement effect of negatively regulated NORAD on sepsis ALI rats (P<0.05). Conclusion Interference with NORAD can alleviate lung injury in ALI rats by regulating the miR-155-5p/TLR6 molecular axis.
Lung injury could be classified as acute and chronic injuries, such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. Lung function recovery mainly depends on inflammation adjusting, lung and airway remodeling, endogenous stem cell proliferation and differentiation, and tissue repair. The principles of clinical therapy include inhibition of inflammation, balancing coagulation and fibrinolysis, and protective lung ventilation for acute lung injury; while reduction of hyper-secretion, bronchodilation, adjusting airway mucosal inflammation and immunity, as well as improving airway remodeling for chronic obstructive pulmonary disease. The functional recovery of lung and airway depends on endogenous stem cell proliferation and repair. The purpose of clinical treatment is to provide assistance for lung and airway repair besides pathophysiological improvement.
Objective To investigate the changes in osteoprotegerin (OPG) / receptor activator of nuclear factor-κB ligand (RANKL) ratio in sepsis-associated acute lung injury (SA-ALI) and the role of regulation of this ratio on the inflammatory response in SA-ALI. Methods Eighteen C57BL/6 male mice were randomly divided into sham operation group, cecal ligation and perforation (CLP) group and RANKL group, with 6 mice in each group. Before the experiment, the RANKL group was intraperitoneally injected with 5 μg (0.2 mL) of recombinant RANKL antibody, whereas both the sham operation group and the CLP group were intraperitoneally injected with a volume-matched normal saline. One hour later, the sham operation group underwent only abdominal exploration and repositioning, while the other groups underwent the CLP surgery to induce the SA-ALI model. After 24 h of modelling, all mice were sacrificed and samples were collected. Pathological evaluation of lung tissues was performed by haematoxylin-eosin staining; enzyme-linked immunosorbent assay was used to detect serum concentrations of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β; while the mRNA and protein expression of OPG and RANKL, along with their ratio values, were detected by real-time polymerase chain reaction for quantitative analysis and protein immunoblotting. Results The SA-ALI mouse model was successfully established. Compared with the sham operation group, mice in the CLP group showed disturbed alveolar structure, obvious alveolar and interstitial haemorrhage and inflammatory cell infiltration, elevated serum levels of IL-6, TNF-α and IL-1β (P<0.05), significantly increased mRNA and protein expression of OPG and elevated OPG/RANKL ratio in lung tissue (P<0.05), whereas RANKL mRNA and protein expression was significantly decreased (P<0.05). Compared with the CLP group, the pathological damage of lung tissue in the RANKL group was reduced, the infiltration of alveolar and interstitial inflammatory cells was significantly improved, and the alveolar structure and morphology were more regular, with lower serum levels of IL-6, TNF-α and IL-1β (P<0.05), significantly lower mRNA and protein expression of OPG and OPG/RANKL ratio in lung tissue (P<0.05), and significantly higher mRNA and protein expression of RANKL in lung tissue (P<0.05). Conclusion The alteration of OPG/RANKL ratio may be related to the pathophysiological process of SA-ALI, and the decrease in its level may reflect the attenuation of the inflammatory response in SA-ALI.
ObjectiveTo investigate the protective effect of atomized inhalation of nano-luteolin preparation on acute lung injury caused by extracorporeal circulation, and to explore the anti-inflammatory mechanism of luteolin, so as to provide study basis for clinical application.MethodsThirty male SD rats aged 5-6 weeks and weighting 160-190 g, were randomly divided into a preoperative baseline (BL) group, arteriovenous partial diversion (ECC) group, luteolin atomization pretreatment for 1 h group, 2 h group, and 3 h group by random number method, with 6 rats in each group. In the BL group, lung tissue samples were collected directly without any treatment. The ECC group received mechanical ventilation, and the whole body was heparinized after the jugular arteriovenous intubation. The flow was transferred for 30 minutes, followed by observation for 60 minutes, then lung tissue samples were collected. Subjects in the 1 h, 2 h and 3 h groups were placed in a small animal atomizer 1 h, 2 h and 3 h before flow transfer respectively, and the subsequent operation was the same as that in the ECC group. The inflammatory level of lung tissue was detected to evaluate the degree of pathological injury of lung tissue. Western blotting (WB) was used to detect the contents of p65, IKKα, IKKβ and IKKγ in the cytoplasm of lung tissue samples of each group.ResultsCompared with the ECC group, the levels of IL-6 and TNF-α in lung tissues and the degree of pathological injury in the 1 h, 2 h and 3 h groups decreased, and the difference between the 3 h group and the ECC group was statistically different (P<0.05). WB results showed that compared with the ECC group, the levels of p65 in lung tissue of the 1 h, 2 h and 3 h groups decreased; the levels of IKKβ in the lung tissue increased in the 1 h, 2 h and 3 h groups, and the difference of the 3 h group was statistically different from the ECC group (P<0.05).ConclusionLuteolin has a protective effect on acute lung injury induced by ECC, and atomization 3 h in advance has the best protective effect on lung. The mechanism plays a protective role in ECC-induced acute lung injury, may be through inhibition of IKKβ phosphorylation, thereby inhibiting the classical NF-κB signaling pathway.
Objective To investigate the protective effect of annexin A1 (ANXA1) derived from human umbilical cord mesenchymal stem cells (HucMSCs) on lipopolysaccharide (LPS) -induced acute lung injury (ALI). Methods Six-week-old male C57BL/6 mice were randomly divided into a sham group, a LPS group, a LPS+HucMSC-cm (LPS+cm) group, a LPS+nc-cm group, and a LPS+si-cm group, with 6 mice in each group. LPS (5 mg/kg) was intratracheally injected to induce ALI model. Then, normal saline, HucMSC-cm (HucMSC conditioned medium), HucMSC-nc-cm (normal ANXA1 expression) and HucMSC-si-cm (knockout of ANXA1) were injected intratracheally with 50 μL each after LPS treatment for 4 hours. After 72 hours of LPS administration, the mice were killed, and the blood and lung tissues were retained. After corresponding treatment, the blood and lung tissues were preserved. The expression of IL-6 in peripheral blood of mice was detected by enzyme-linked immunosorbnent assay, the pathological changes of lung tissues were observed by hematoxylin-eosin staining, and the expressions of interleukin-6 (IL-6) and vascular cell adhesion molecule-1 (VCAM-1) in lung tissues of each group were detected by Western blot and immunohistochemistry. Results Compared with the sham group, the lung histopathology of mice in the LPS group showed significantly increased inflammatory factor infiltration, alveolar collapse, and lung tissue structure destruction as well as lung tissue injury score and wet/dry weight ratio (W/D) increased (all P<0.05). Accordingly, IL-6 and VCAM-1 protein levels in lung tissue and IL-6 expression in peripheral blood were increased (all P<0.05). Compared with the LPS group, the pathological injury of lung tissue in the LPS+cm group was improved, the lung tissue injury score and the W/D ratio decreased while IL-6, VCAM-1 protein levels in lung tissue and IL-6 expression in peripheral blood were decreased (all P<0.05). But there were no significant differences between the LPS+cm group and the LPS+ nc-cm group (all P>0.05). Compared with the LPS+nc-cm group, lung tissue pathological injury was aggravated again, lung tissue injury score and W/D were also increased in the LPS+si-cm group (all P<0.05). IL-6 and VCAM-1 protein levels in lung tissue and IL-6 expression in peripheral blood were increased again (all P<0.05). Conclusion ANXA1 derived from HucMSCs has certain protective effect in LPS-induced ALI model.
ObjectiveTo study the expression of cytokine-induced neutrophil chemoattractant-1(CINC-1)in rats with transfusion-related acute lung injury(TRALI),explore its possible role in the pathogenesis of TRALI.
MethodsSixty Sprague-Dawley rats were randomly divided into a normal control group with sham operation,a positive control group with ALI induced by intravenous infusion of lipopolysaccharide(5 mg/kg),and a TRALI group treated by intraperitoneal injection of LPS 2h before the transfusion of human plasma (1mL),a LPS control group treated by intraperitoneal injection of LPS 2h before the transfusion of normal saline(1mL).The reverse transcription-polymerase chain (RT-PCR)was used to detect CINC-1 mRNA.The level of CINC-1 in lung tissue homogenate was measured by ELISA.Morphological changes of the lung tissue were observed under light microscope.Myeloperoxidase (MPO)in lung homogenate and wet lung weight to dry lung weight ratio (W/D)were observed.The number of cells and the percentage of polymorphonuclear neutrophil (PMN)in Bronchoalveolar lavage fluid (BALF)were also compared.
ResultsCompared with the normal control group and the LPS control group,the expression of CINC-1 protein and CINC-1 mRNA were increased significantly in lung of the positive control group and the TRALI group(P<0.05).The number of cells and the percentage of PMN in BALF of the TRALI group [(310.63±76.67)×106/L and (33.57±11.51)%] were significantly higher than those in BALF of the normal control group [(101.36±63.83)×106/L and (9.87±3.56)%](P<0.05).Tissue water content and MPO activity in the TRALI group were significantly higher than those in the normal control group (P<0.05).
ConclusionExpression of CINC-1 protein and CINC-1 mRNA are increased in the rat lung with TRALI and PMN infiltration in lung tissue,which suggests CINC-1 participate in the process of the PMN and endothelial cell adhesion and may play an important role in the pathogeneses of TRALI.
Objective To explore the effect of early short-term use of low-dose steroids on early acute lung injury (EALI) after video-assisted thoracoscopic lobectomy. Methods Patients who underwent video-assisted thoracoscopic lobectomy in our department from January 2019 to January 2022 were selected for this retrospective cohort study. They were divided into an early steroid treatment group and a control group based on whether steroids were used in the early postoperative period. In the early steroid treatment group, in addition to routine postoperative treatment, low-dose methylprednisolone was administered intravenously, at 80-120 mg/d for 3 consecutive days. In the control group, routine postoperative treatment was given, but no steroids were used in the first 3 days. A chest computed tomography (CT) scan was performed on postoperative day (POD) 1, and POD3 or POD4 to assess lung injury. Chest CT scores, the EALI incidence, the length of hospital stay, and the incidence of poor incision healing were recorded. ResultsA total of 521 patients were included, consisting of 255 males and 266 females, aged 11-80 years. There were 203 patients in the early steroid treatment group and 318 patients in the control group. On POD1, the incidence of EALI was 16.0% in the control group and 13.8% in the steroid group, with no significant difference between the two groups (P>0.05). There was also no significant difference in the CT scores of patients with EALI in the two groups (P>0.05). On POD3/4, the incidence of EALI was 33.6% in the control group and 22.7% in the steroid group, showing a significant difference (P=0.007). When comparing the CT scores of patients with EALI in both groups, the scores were lower in the steroid group, but the difference was not significant (P>0.05). The overall incidence of EALI on POD1-4 was 37.4% in the control group and 26.1% in the steroid group, showing a significant difference (P=0.007). Of these, 28.9% of patients in the control group showed radiological progression, which means new EALI occurred or existing EALI progressed, while the progression rate was 14.8% in the steroid group (P<0.001). The length of hospital stay was significantly shorter in the steroid group compared to the control group (P<0.001), but the incidence of poor incision healing was not (P>0.05). Conclusion Early use of corticosteroids cannot reduce the incidence and severity of EALI on POD1, but it can reduce the incidence of EALI on POD3/4 and decrease the risk of radiological progression, and also lower the overall risk of EALI after surgery, without extended postoperative hospital stays or increased incidence of poor incision healing. Therefore, early postoperative use of low-dose corticosteroids can help to inhibit the occurrence and progression of EALI. It is suggested to use as early as possible especially in patients with high risks of postoperative EALI.
Seawater drowning leads to acute lung tissue structure injury, lung ventilation and air exchange dysfunction, acute pulmonary edema, and even acute respiratory failure. The pathogenesis of seawater induced acute lung injury is complex, involving inflammatory response, pulmonary edema, pulmonary surfactant, oxidative stress, apoptosis and autophagy. Timely and effective treatment is the key to reduce the mortality and disability rate of patients with seawater induced acute lung injury. This article summarizes the research progress in the pathogenic mechanism and treatment strategy of seawater induced acute lung injury, aiming to provide reference for the comprehensive treatment of seawater induced acute lung injury patients in clinical work and subsequent related research.
ObjectiveTo investigate the effect of different administration methods of tranexamic acid on postoperative pulmonary inflammation response during cardiopulmonary bypass (CPB).MethodsA total of 64 SD rats were included in the study. They were randomly divided into eight different groups. CPB model was established for the operation groups. The rats in the operation groups were given tranexamic acid at low (25 mg/kg), medium (50 mg/kg) or high (100 mg/kg) concentrations before or after the CPB. Blood cells count and coagulation function were assessed 1 hour after surgery. The concentration of interleukin (IL)-1β、IL-6 and tumor necrosis factor (TNF)-α in blood and lung lavage fluid were measured. The infiltration of inflammatory cells in lungs was observed by hematoxylin-eosin (HE) staining.ResultsThe concentration of inflammatory cells in the operation groups was higher than that in the control group (P<0.05). The use of tranexamic acid inhibited the increase of IL-6 and TNF-α in whole blood and lung lavage fluid due to CPB (P<0.05), but there was no significant difference among the experimental groups (P>0.05). Tranexamic acid could reduce the exudation of inflammatory cells in the lungs.ConclusionThe use of tranexamic acid can effectively reduce the release of inflammatory factors and reduce acute lung injury caused by CPB in rat models. But simply increasing the dose or changing the timing of administration is not more effective in reducing the intensity of the inflammatory response.
Acute lung injury is a kind of common complication after cardiopulmonary bypass. Acute lung injury is attributed to the ischemia-reperfusion injury and systemic inflammatory response syndrome. Several factors common in cardiac surgery with cardiopulmonary bypass may worsen the risk for acute lung injury including atelectasis, transfusion requirement, older age, heart failure, emergency surgery and prolonged duration of bypass. Targets for prevention of acute lung injury include mechanical, surgical and anesthetic interventions that aim to reduce the contact activation, systemic inflammatory response, leukocyte sequestration and hemodilution associated with cardiopulmonary bypass. We aim to review the etiology, risk factors and lung protective strategies for acute lung injury after cardiopulmonary bypass.
