Objective To investigate whether p38 mitogen activated protein kinase (p38MAPK) inhibitor can reduce acute lung injury (ALI) caused by lipopolysaccharide (LPS) by regulating Th17/Treg balance. Methods Balb/c mice were randomly divided into a control group, an ALI group and an intervention group. The mice in the control group were injected with phosphate-buffered saline, the mice in the ALI group were intraperitoneally injected with 40 mg/kg LPS, and the mice in the intervention group were injected with SB203580 (0.5 mg/kg, 1 mg/kg, 2 mg/kg, 5 mg/kg) intraperitoneally 1 h prior to the intraperitoneal injection of LPS. All mice were killed on 12 h later respectively. Hematoxylin-eosinstin staining was used to observe the pathological changes of lung tissue, and cell classification, counting, and total protein levels in bronchoalveolar lavage fluid (BALF) were detected. Transcript expression of forkhead box p3 (Foxp3) and retinoic acid receptor-related orphan receptor-γt (RORγt) was detected by real-time polymerase chain reaction. Interleukin (IL)-6, IL-10, IL-17, IL-23 and transforming growth factor-β (TGF-β) in lung tissue and IL-6, tumor necrosis factor-α (TNF-α) in serum were measured by enzyme-linked immunosorbent assay. The Th17 and Treg subset distribution in spleen was determined by flow cytometry. Results Histopathological examination showed that LPS induced inflammatory cell infiltration in lung tissue, increased cell count and protein levels in BALF (P<0.05), and increased proportion of neutrophils and monocytes in the ALI mice. SB203580 significantly attenuated tissue injury of the lungs in LPS-induced ALI mice. Serum levels of IL-6 and TNF-α in the ALI group were significantly higher than those in the control group, and inflammatory cytokines were decreased after SB203580 intervention. Compared with the ALI group, the production of inflammatory cytokines associate with Th17, including IL-17, IL-23, RORγt was inhibited, and the production of cytokines associate with Treg, such as IL-10 and Foxp3 in lung tissue was increased in the intervention group in a concentration-dependent manner with SB203580. After SB203580 intervention, Th17/Treg ratio was significantly decreased compared with the LPS group (P<0.05). Conclusion p38MAPK inhibitor can reduce LPS-induced ALI by regulating the imbalance of Treg cells and Th17 cells.
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.
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.
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.
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 investigate the effects of wedelolactone (WEL) on lipopolysaccharide (LPS)-induced pyroptosis of alveolar epithelial cells and AMP-activated protein kinase/nucleotide binding oligomeric domain like receptor 3 (NLRP3)/cysteinyl aspartate specific proteinase-1 (Caspase-1) signaling pathway. Methods Human lung epithelial cells BEAS-2B were treated with 5 - 200 μmol/L wedelolactone, and cell activity was detected using MTT assay. The alveolar epithelial cells were divided into control group, lipopolysaccharide group (LPS group), 10 μmol/L wedelolactone group (WEL-L group), 20 μmol/L wedelolactone group (WEL-M group), 40 μmol/L wedelolactone group (WEL-H group), 40 μmol/L wedelolactone+10 μmol/L AMPK inhibitor Compound C group (WEL-H+Compound C group), and 20 μmol/L Caspase-1 inhibitor Z-YVAD-FMK group (Z-YVAD-FMK group). Transmission electron microscopy was applied to observe the microstructure of cells. ELISA was applied to detect levels of inflammatory factors such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-8 (IL-8). Immunofluorescence was applied to detect Caspase-1 and gasdermin family proteins (DGSDMD). Western blot was applied to detect protein expression levels of AMPK, NLRP3, and Caspase-1. Results Wedelolactone concentrations of 10, 20 and 40 μmol/L were selected for follow-up experiments. Compared with Control group, LPS group showed decreased cell activity, severe damage, cell contraction, mitochondrial ridge breakage and decreased number, increased levels of TNF-α, IL-1β, IL-8 and GSDMD, NLRP3, Caspase-1 expression, and decreased p-AMPK/AMPK expression (P<0.05). Wedelolactone treatment could significantly improve LPS-induced pyrosis of alveolar epithelial cells (P<0.05). Compound C could partially reverse the effect of wedelactone on LPS-induced pyrodeath of alveolar epithelial cells (P<0.05). Z-YVAD-FMK treatment also significantly improved LPS-induced pyroptosis of alveolar epithelial cells (P<0.05). Conclusion Wedelolactone can inhibit LPS-induced pyroptosis of pulmonary alveolar epithelial cells by inhibiting AMPK/NLRP3/Caspase-1 signaling pathway.
Objective To analyze the role of lienal polypeptide injection in acute lung injury induced by lipopolysaccharide (LPS) in rats. Methods Eighty male SD rats were randomly allocated into 4 groups: a LPS group, a control group, a lienal polypeptide group and a LPS+ lienal polypeptide group (20 rats in each group). Lienal polypeptide or normal saline was given with an intramuscular injection 30 min after an intraperitoneal injection of LPS (5 mg/kg). The severity of pulmonary injury was evaluated 4 h after LPS challenge by enzyme-linked immunosorbent assay (ELISA), wet-to-dry weight ratio, hematoxylin and eosin (HE) staining, TUNEL and Western blotting. Results Lienal polypeptide injection treatment significantly attenuated LPS-induced pulmonary histopathologic changes, alveolar hemorrhage, and neutrophil infiltration. Moreover lienal polypeptide injection significantly suppressed LPS-induced activation of metastasis-associated protein-1 (MTA1). Conclusion Lienal polypeptide injection is demonstrated to protect rats from LPS-induced acute lung injury by the expression of MTA1.
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.
Objective To investigate the effect and potential mechanism of bone marrow mesenchymal stem cells (BMSCs) - derived extracellular vesicles (EVs) on lung tissue injury in mice with severe acute pancreatitis (SAP). Methods A total of 24 specific pathogen free grade male C57BL/6 mice and primary mouse lung microvascular endothelial cells (PMVECs) were selected. The mice were divided into sham group, SAP group, and BMSC group, with 8 mice in each group. The mouse primary PMVECs were divided into model group [sodium taurocholate (NaTC) group], BMSC-EV group, and control group. Extraction and characterization of healthy mouse BMSCs and their derived extracellular vesicles (BMSC-EVs) were conducted. A mouse model of SAP was established, and BMSC-EVs were injected into SAP mice by tail vein or intervened in PMVECs in vitro, to observe the pathological damage of pancreatic and lung tissues, the changes of serum amylase, lipase, and inflammatory factors [tumor necrosis factor α (TNF-α), interleukin-6 (IL-6)], the expression of inflammatory factors of lung tissues and PMVECs, and the endothelial cell barrier related proteins [E-cadherin, ZO-1, intercellular cell adhesion molecule-1 (ICAM-1)], and tight junctions between PMVECs to explore the effects of BMSC-EVs on pancreatic and lung tissues in SAP mice and PMVECs in vitro. Results BMSCs had the potential for osteogenic, chondrogenic, and lipogenic differentiation, and the EVs derived from them had a typical cup-shaped structure with a diameter of 60-100 nm. BMSC-EVs expressed the extracellular vesicle-positive proteins TSG101 and CD63 and did not express the negative protein Calnexin. Compared with the mice in the sham group, the SAP mice underwent significant pathological damage to the pancreas (P<0.05), and their serum amylase, lipase, inflammatory factor IL-6, and TNF-α levels were significantly up-regulated (P<0.05); whereas, BMSC-EVs markedly ameliorated the pancreatic tissue damage in the SAP mice (P<0.05), down-regulated the levels of peripheral serum amylase, lipase, IL-6 and TNF-α (P<0.05), and up-regulated the level of anti-inflammatory factor IL-10 (P<0.05). In addition to this, the SAP mice showed significant lung histopathological damage (P<0.05), higher neutrophils and macrophages infiltration (P<0.05), higher levels of the inflammatory factors TGF-β and IL-6 (P<0.05), as well as reduced barrier protein E-cadherin, ZO-1 expression and elevated expression of ICAM-1 (P<0.05). BMSC-EVs significantly ameliorated lung histopathological injury, inflammatory cells infiltration, inflammatory factor levels, and expression of barrier proteins, and suppressed ICAM-1 expression (P<0.05). In the in vitro PMVECs experiments, it was found that intercellular tight junctions were broken in the NaTC group, and the levels of inflammatory factors TNF-α and IL-6 were significantly up-regulated (P<0.05), the protein expression of E-cadherin and ZO-1 was significantly down-regulated (P<0.05), and the expression of ICAM-1 was significantly up-regulated (P<0.05). BMSC-EVs significantly improved intercellular tight junctions in the NaTC group and inhibited the secretion of TNF-α and IL-6 (P<0.05), up-regulated the expression of the barrier proteins E-cadherin and ZO-1, and down-regulated the expression of ICAM-1 (P<0.05). Conclusion BMSC-derived EVs ameliorate lung tissue injury in SAP mice by restoring the lung endothelial cell barrier and inhibiting inflammatory cell infiltration.
急性肺损伤（ALI）和急性呼吸窘迫综合征（ARDS）是指由心源性以外的各种肺内外致病因素所导致的急性进行性缺氧性呼吸衰竭，它们具有性质相同的病理生理改变，严重的ALI或ALI的最终严重阶段被定义为ARDS，临床表现以呼吸窘迫、顽固性低氧血症和非心源性肺水肿为特征，采用常规的治疗难以纠正其低氧血症，死亡率高达60%。目前，有关ALI/ARDS的研究取得较多进展，其中，能有效评估ALI病情和预测死亡率的临床参数和生化指标一直是研究热点。