Intravenous transplantation of mesenchymal stem cells attenuates oleic acid induced acute lung injury in rats

Background Acute lung injury （ALl） and end-stage acute respiratory distress syndrome （ARDS） were among the most common causes of death in intensive care units. The activation of an inflammatory response and the damage of pulmonary epithelium and endotheliumwerethe hallmark of ALI/ARDS. Recent studies had demonstrated the importance of mesenchymal stem cells （MSCs） in maintaining the normal pulmonary endothelial and epithelial function as well as participating in modulating the inflammatory response and they are involved in epithelial and endothelial repair after injury. Here, our study demonstrates MSCs therapeutic potential in a rat model of ALI/ARDS. Methods Bone marrow derived MSCs were obtained from Sprague-Dawley （SD） rats and their differential potential was verified. ALl was induced in rats byoleic acid （OA）, and MSCs were transplanted intravenously. The lung injury and the concentration of cytokines in plasma and lung tissue extracts were assessed at 8 hours, 24 hours and 48 hours after OA-injection. Results The histological appearance and water content in rat lung tissue were significantly improved at different time points in rats treated with MSCs. The concentration of tumor necrosis factor-a and intercellular adhesion molecular-1 in rats plasma and lung tissue extracts were significantly inhibited after intravenous transplantation of MSCs, whereas interleukin-10 was significantly higher after MSCs transplantation at 8 hours, 24 hours and 48 hours after OA-challenge. Conclusions Intravenous transplantation of MSCs could maintain the integrity of the pulmonary alveolar-capillary barrier and modulate the inflammatory response to attenuate the experimental ALI/ARDS. Transplantation of MSCs could be a novel cell-based therapeutic strategy for prevention and treatment of ALI/ARDS.

Effects of low potassium dextran glucose solution on oleic acid-induced acute lung injury in juvenile piglets

Background Epithelial dysfunction in lungs plays a key role in the pathogenesis of acute lung injury. The beneficial effects of low potassium dextran glucose solution （LPD） have been reported in lung preservation, and LPD enables injured alveolar pneumocytes to recover. So we hypothesized that systemic administration of LPD may have benefits in treating acute lung injury. We investigated the effects of LPD on arterial blood gas and levels of some cytokines in oleic acid-induced acute lung injury in juvenile piglets.Methods Oleic acid （0.1 ml/kg） was intrapulmonarily administered to healthy anesthetized juvenile piglets. Ten animals were randomly assigned to two groups （n=5 each）： oleic acid-induced group （control group） with intravenous infusion of 12.5 ml/kg of lactated Ringer＇s solution 30 minutes before administration of oleic acid and LPD group with systemic administration of LPD （12.5 ml/kg） 30 minutes before injecting oleic acid. Blood gas variables and concentrations of tumor necrosis factor alpha, endothelin 1 and interleukin 10 were measured before and every 1 hour for 6 hours after initial lung injury.Results Compared with control group, blood pH, partial pressure of arterial oxygen to fraction of inspired oxygen ratio,partial pressure of arterial carbon dioxide, and mean pulmonary arterial pressure in LPD group were improved （P＜0.05or 0.01）. Six hours after lung injury, concentration of tumor necrosis factor alpha in lung tissue was lower in LPD group than control group （P＜0.05）. Plasmic concentration of endothelin 1 showed lower in LPD group while plasmic concentration of interleukin 10 showed higher in LPD group （P＜0.05）.Conclusions Before lung injury, systemic administration of LPD can improve gas exchange, attenuate pulmonary hypertension, decrease plasmic levels of endothelin 1, increase interleukin 10 and decrease concentration of tumor necrosis factor alpha in lung tissue in oleic acid-induced acute lung injury in juvenile piglets.

Effect of oleic acid-induced acute lung injury and conventional mechanical ventilation on renal function in piglets

Background Animal models that demonstrate changes of renal function in response to acute lung injury （ALl） and mechanical ventilation （MV） are few. The present study was performed to examine the effect of ALl induced by oleic acid （OA） in combination with conventional MV strategy on renal function in piglets. Methods Twelve Chinese mini-piglets were randomly divided into two groups： the OA group （n=6）, animals were ventilated with a conventional MV strategy of 12 ml/kg and suffered an ALl induced by administration of OA, and the control group （n=6）, animals were ventilated with a protective MV strategy of 6 ml/kg and received the same amount of stedle saline. Results Six hours after OA injection a severe lung injury and a mild-moderate degree of renal histopathological injury were seen, while no apparent histological abnormalities were observed in the control group. Although we observed an increase in the plasma concentrations of creatinine and urea after ALl, there was no significant difference compared with the control group. Plasma concentrations of neutrophil gelatinase-associated lipocalin （NGAL） and cystatin C increased （5.6＋1.3） and （7.4＋1.5） times in the OA group compared to baseline values, and were significantly higher than the values in the control group. OA injection in combination with conventional MV strategy resulted in a dramatic aggravation of hemodynamic and blood gas exchange parameters, while these parameters remained stable during the experiment in the control group. The plasma expression of TNF-a and IL-6 in the OA group were significantly higher than that in the control group. Compared with high expression in the lung and renal tissue in the OA group, TNF-a and IL-6 were too low to be detected in the lung and renal tissue in the control group. Conclusions OA injection in combination with conventional MV strategy not only resulted in a severe lung injury but also an apparent renal injury. The potential mechanisms involved a cytokine response of TNF-a and IL-6 in plasma, lung and renal tissues.

Acute lung injury and acute respiratory distress syndrome： experimental and clinical investigations

Acute lung injury （ALl） or acute respiratory distress syndrome （ARDS） can be associated with various disorders. Recent investigation has involved clinical studies in collaboration with clinical investigators and pathologists on the pathogenetic mechanisms of ALl or ARDS caused by various disorders. This literature review includes a brief historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the long-term experimental studies and clinical investigations from our laboratory, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

Crotalaria ferruginea extract attenuates lipopolysaccharide-induced acute lung injury in mice by inhibiting MAPK/NF-κB signaling pathways

Objective:To evaluate the anti-inflammatory activity of Crotalaria ferruginea extract(CFE)and its mechanism.Methods:An intratracheal lipopolysaccharide(LPS)instillationinduced acute lung injury(ALI)model was used to study the antiinflammatory activity of CFE in vivo.The LPS-induced shock model was used to analyze the effect of CFE on survival.LPS-stimulated RAW264.7 cell model was used to investigate the anti-inflammatory activity of CFE in vitro and the effects on mitogen-activated protein kinase(MAPK)or nuclear factor-κB(NF-κB)signaling pathways.Results:CFE administration decreased the number of inflammatory cells,reduced the levels of tumor necrosis factor-α(TNF-α),monocyte chemotactic protein-1(MCP-1),interleukin-6(IL-6),and interferon-γ,and diminished protein content in the bronchoalveolar lavage fluid of mice.CFE also reduced lung wet-to-dry weight ratio,myeloperoxidase,and lung tissue pathological injury.CFE preadministration improved the survival rate of mice challenged with a lethal dose of LPS.CFE reduced LPS-activated RAW264.7 cells to produce nitric oxide,TNF-α,MCP-1,and IL-6.Furthermore,CFE inhibited nuclear translocation and phosphorylation of NF-κB P65,extracellular signal-regulated kinase,c-Jun N-terminal kinases,and P38 MAPKs.Conclusions:CFE exhibits potent anti-inflammatory activity in LPS-induced ALI mice,LPS-shock mice,and RAW264.7 cells,and its mechanism may be associated with the inhibition of NF-κB and MAPK signaling pathways.Crotalaria ferruginea may be a useful therapeutic drug for the treatment of ALI and other respiratory inflammations.

Leptin treatment ameliorates acute lung injury in rats with cerulein-induced acute pancreatitis

AIM:To determine the effect of exogenous leptin on acute lung injury (ALI) in cerulein-induced acute pancreatitis (AP). METHODS:Forty-eight rats were randomly divided into 3 groups. AP was induced by intraperitoneal (i.p.) injection of cerulein (50 μg/kg) four times,at 1 h intervals. The rats received a single i.p. injection of 10 μg/kg leptin (leptin group) or 2 mL saline (AP group) after cerulein injections. In the sham group,animals were given a single i.p. injection of 2 mL saline. Experimental samples were collected for biochemical and histological evaluations at 24 h and 48 h after the induction of AP or saline administration. Blood samples were obtained for the determination of amylase,lipase,tumor necrosis factor (TNF)-a,interleukin (IL)-1β,macrophage inflammatory peptide (MIP)-2 and soluble intercellular adhesion molecule (sICAM)-1 levels,while pancreatic and lung tissues were removed for myeloperoxidase (MPO) activity,nitric oxide (NOx) level,CD40 expression and histological evaluation. RESULTS:Cerulein injection caused severe AP,confirmed by an increase in serum amylase and lipase levels,histopathological findings of severe AP,and pancreatic MPO activity,compared to the values obtained in the sham group. In the leptin group,serum levels of MIP-2,sICMA-1,TNF-a,and IL-1b,pancreatic MPO activity,CD40 expression in pancreas and lung tissues,and NOx level in the lung tissue were lower compared to those in the AP group. Histologically,pancreatic and lungdamage was less severe following leptin administration. CONCLUSION:Exogenous leptin attenuates inflammatory changes,and reduces pro-inflammatory cytokines,nitric oxide levels,and CD40 expression in ceruleininduced AP and may be protective in AP associated ALI.

Moderate hypothermia attenuates lung in flammation inlipopolysaccharide- induced acute lung injury in rats

Objective To investigate the role of moderate h.vpothennia in the lung inflammation of rat acute lung injury induced by lipopolysaccharide(LPS). Methods A rat model of acute lung injury (ALl) was established by in-tin-tracheal instillation of lipopolysaccharide ( 1.5 mg/kg, 0.5 ml) at 16 h after LPS ( 1.0 mg/kg) intraperitoneal adrninis-tmtion. Thirty-four male Sprague Dawley rats were randomly divided into four groups: control group, receiving saline only;LPS group, receiving LPS; hypothennia group, treated with hypothennia without LPS; LPS + hypothennia group, treated with LPS and cooled to 32.5℃-33.0℃ as PaO2/FiO2. was below 300 mmHg. Hemodynamics and blood gases were record-ed every hour throughout the study. Rats were killed 4 h after ALl, and lung lavage was performed to measure the tumor ne-crosis factor α(TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) concentrations in bronchoalveolar lavage fluid (BALF) by using enzyme-linked immunosorbent assay (ELISA). Results PaO2/FiO2 was significantly decreased and PaCO2 was increased in the LPS group as compared to their baseline values( P＜0.01). Treatment with hypothermia inhib-ited the increase in PaCO2( P＜0.05) but had no effect on PaO2/FiO2 in the presence of LPS. The administration of LPS significantly increased the concentrations of TNF-α, IL-6 and IL-10 in BALF as compared to the control experiment( P＜0.05, P＜0.01 ). Moderate hypothermia reduced the expressions of TNF-α and IL-6 ( P＜0.01 ) but had no effect on the production of IL-10 ( P＞0.05). Conclusion Moderate hypothermia significantly inhibits proinflammatory cytokine ex-pressions in lipopolysaccharide-induced acute lung injury.

Total liquid ventilation reduces oleic acid-induced lung injury in piglets

Background Pediatric patients are susceptible to lung injury that does not respond to traditional therapies. Total liquid ventilation has been developed as an alternative ventilatory strategy for severe lung injury. The aim of this study is to investigate the effect of total liquid ventilation on oleic acid （OA）-induced lung injury in piglets. Methods Twelve Chinese immature piglets were induced acute lung injury by OA. Twelve piglets were randomly treated with conventional gas ventilation （control group） or total liquid ventilation （study group） for 240 minutes. Samples for blood gas analysis were collected before, and at 60-minute intervals after OA-induced lung injury. The degree of lung injury was quantified by histologic examination. The inflammatory cells and the levels of IL-1β, IL-6, IL-10 and TNF-α in plasma, tissue and bronchoalveolar lavage were analyzed. Results Neutrophil and macrophage counts in bronchoalveolar lavage were significantly decreased in the study group （P〈0.05）. The total lung injury score was also reduced in the study group （P〈0.05）. The concentrations of IL-1β, IL-6, IL-10 and TNF-α in plasma, tissue and bronchoalveolar lavage were significantly reduced in the study group （P〈0.05）. Conclusions Total liquid ventilation reduces biochemical and histoloaic OA-induced luna iniurv in nialets.

Tanshinone ⅡA prevents acute lung injury by regulating macrophage polarization

Objective: Acute lung injury(ALI) is a serious respiratory dysfunction caused by pathogen or physical invasion. The strong induced inflammation often causes death. Tanshinone ⅡA(Tan-ⅡA) is the major constituent of Salvia miltiorrhiza Bunge and has been shown to display anti-inflammatory effects. The aim of the current study was to investigate the effects of Tan-ⅡA on ALI.Methods: A murine model of lipopolysaccharide(LPS)-induced ALI was used. The lungs and serum samples of mice were extracted at 3 days after treatment. ALI-induced inflammatory damages were confirmed from cytokine detections and histomorphology observations. Effects of Tan-ⅡA were investigated using in vivo and in vitro ALI models. Tan-ⅡA mechanisms were investigated by performing Western blot and flow cytometry experiments. A wound-healing assay was performed to confirm the Tan-ⅡA function.Results: The cytokine storm induced by LPS treatment was detected at 3 days after LPS treatment, and alveolar epithelial damage and lymphocyte aggregation were observed. Tan-ⅡA treatment attenuated the LPS-induced inflammation and reduced the levels of inflammatory cytokines released not only by inhibiting neutrophils, but also by macrophage. Moreover, we found that macrophage activation and polarization after LPS treatment were abrogated after applying the Tan-ⅡA treatment. An in vitro assay also confirmed that including the Tan-ⅡA supplement increased the relative amount of the M2 subtype and decreased that of M1. Rebalanced macrophages and Tan-ⅡA inhibited activations of the nuclear factor-κB and hypoxia-inducible factor pathways. Including Tan-ⅡA and macrophages also improved alveolar epithelial repair by regulating macrophage polarization.Conclusion: This study found that while an LPS-induced cytokine storm exacerbated ALI, including Tan-ⅡA could prevent ALI-induced inflammation and improve the alveolar epithelial repair, and do so by regulating macrophage polarization.

Synthesis and evaluation of 2-cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide as a potent anti-inflammatory agent for intervention of LPS-induced acute lung injury

The present study was designed to synthesize 2-Cyano-3, 12-dioxooleana-1, 9(11)-en-28-oate-13β, 28-olide(1), a lactone derivative of oleanolic acid(OA) and evaluate its anti-inflammatory activity. Compound 1 significantly diminished nitric oxide(NO) production and down-regulated the m RNA expression of iNOS, COX-2, IL-6, IL-1β, and TNF-α in lipopolysaccharide(LPS)-stimulated RAW264.7 cells. Further in vivo studies in murine model of LPS-induced acute lung injury(ALI) showed that 1 possessed more potent protective effects than the well-known anti-inflammatory drug dexamethasone by inhibiting myeloperoxidase(MPO) activity, reducing total cells and neutrophils, and suppressing inflammatory cytokines expression, and thus ameliorating the histopathological conditions of the injured lung tissue. In conclusion, compound 1 could be developed as a promising anti-inflammatory agent for intervention of LPS-induced ALI.

Protection of Total Flavonoid Fraction from Nervilia fordii on Lipopolysaccharide-induced Acute Lung Injury in Rats

Objective To investigate the effects of total flavonoid fraction(TFF) from Nervilia fordii on lipopolysaccharide(LPS)-induced acute lung injury(ALI) in rats,and to explore their protective mechanism.Methods LPS-induced ALI model was established by LPS(5 mg/kg) injection via left cervical vein.Blood samples were collected from the cervical artery of all rats at 5 and 6 h after LPS challenge for arterial blood gas test and cytokines measurements,and pulmonary microvascular permeability(PMP),lung wet/dry weight ratio(W/D),and pathological features were observed.Results Phytochemical study showed that the TFF contained 67.3% of flavonoids expressed in rutin and three flavone glycosides.The TFF pretreatment(6.24 and 12.48 mg/kg) attenuated the partial arterial pressure of oxygen decline in blood significantly,and decreased the PMP and lung W/D in ALI rats.In addition,the TFF(6.24 and 12.48 mg/kg) also ameliorated the LPS-induced lung damages including alveolar edema,neutrophils infiltration,alveolar hemorrhage,and thickening of the alveolar wall.Furthermore,the treatment with the TFF(6.24 and 12.48 mg/kg) also down-regulated the levels of pro-inflammatory cytokines,such as tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and intercellular adhesion molecule-1(ICAM-1),and up-regulated the level of anti-inflammatory cytokine IL-10 in serum of ALI rats simultaneously.Conclusion These results suggest that the TFF could protect LPS-induced ALI in rats,which may be mediated,at least in part,by adjusting the production of inflammatory cytokines including TNF-α,IL-6,ICAM-1,and IL-10.

Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis

AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway.

C/EBP homologous protein deficiency aggravates acute pancreatitis and associated lung injury

AIM:To investigate the pathophysiological role of C/EBP homologous protein(CHOP)in severe acute pancreatitis and associated lung injury.METHODS:A severe acute pancreatitis model was induced with 6 injections of cerulein(Cn,50μg/kg)at 1-h intervals,then intraperitoneal injection of lipopolysaccharide(LPS,7.5 mg/kg)in CHOP-deficient(Chop-/-)mice and wild-type(WT)mice.Animals were sacrificed under anesthesia,3 h or 18 h after LPS injection.Serum amylase,lipase,and cytokines[interleukin(IL)-6 and tumor necrosis factor(TNF)-α],pathological changes,acute lung injury,and apoptosis in the pancreas were evaluated.Serum amylase and lipase activities were detected using a medical automatic chemical analyzer.Enzyme-linked immunosorbent assay kits were used to evaluate TNF-αand IL-6 levels in mouse serum and lung tissue homogenates.Apoptotic cells in sections of pancreatic tissues were determined by terminal deoxynucleotidyl transferase-mediated dUTPbiotin nick-end labeling(TUNEL)analysis.The mouse carotid arteries were cannulated and arterial blood samples were collected for PaO2analysis.The oxygenation index was expressed as PaO2/FiO2.RESULTS:Administration of Cn and LPS for 9 and 24 h induced severe acute pancreatitis in Chop-/-and WT mice.When comparing Chop-/-mice and WT mice,we observed that CHOP-deficient mice had greater increases in serum TNF-α(214.40±19.52 pg/mL vs 150.40±16.70 pg/mL;P=0.037),amylase(4236.40±646.32U/L vs 2535.30±81.83 U/L;P=0.041),lipase(1678.20±170.57 U/L vs 1046.21±35.37 U/L;P=0.008),and IL-6(2054.44±293.81 pg/mL vs 1316.10±108.74pg/mL;P=0.046)than WT mice.The histopathological changes in the pancreases and lungs,decreased PaO2/FiO2ratio,and increased TNF-αand IL-6 levels in the lungs were greater in Chop-/-mice than in WT mice(pancreas:Chop-/-vs WT mice,hemorrhage,P=0.005;edema,P=0.005;inflammatory cells infiltration,P=0.005;total scores,P=0.006;lung:hemorrhage,P=0.017;edema,P=0.017;congestion,P=0.017;neutrophil infiltration,P=0.005,total scores,P=0.001;PaO2/FiO2ratio:393±17.65 vs 453.8,P=0.041;TNF-α:P=0.043;IL-6,P=0.040).Results from TUNEL analysis indicated increased acinar cell apoptosis in mice following the induction of acute pancreatitis.However,Chop-/-mice displayed significantly reduced pancreatic apoptosis compared with the WT mice(201.50±31.43vs 367.00±47.88,P=0.016).CONCLUSION:These results suggest that CHOP can exert protective effects against acute pancreatitis and limit the spread of inflammatory damage to the lungs.

Effect of SP-A/B in lipoic acid on acute paraquat poisoning

BACKGROUND: This study was undertaken to observe the concentration of SP-A/B and the pulmonary surfactant in the lung tissue of rats with acute lung injury/acute respiratory distress syndrome caused by paraquat poisoning after the treatment of metabolic antioxidant-lipoic acid and whether its influence was related to TNF-α.METHODS: Sixty-six male Sprage-Dawley rats were randomly divided into three groups: normal control group(NS group), 6 rats; paraquat poisoning group(PQ group), 30 rats; and paraquat+lipoic acid treatment group(LA group), 30 rats. The rats in the PQ and LA groups were subdivided into 3-, 6-, 12-, 24-, 48-hour subgroups, with 6 rats in each group. After the rats were sacrificed, lung tissue from the same part was taken from the rats. After HE staining, histological changes were observed in the tissue under a light microscope. Lung tissue was also taken to test the levels of superoxide dismutase(SOD) and malondialdehyde(MDA). Whole blood(0.8 mL) without anticoagulant was drawn from the tail vein of rats for the determination of the TNF-α level. The total RNA of the lung tissue was collected, and the Rt-PCR method was used to measure the levels of SP-A and SP-B mRNA.RESULTS: HE staining showed that histopathological changes were milder in the LA group than in the PQ group. There were significant differences in MDA and SOD levels between different intervals both in intergroups and intragroups except the 3-hour subgroup(P<0.01). Likewise, the significant differences in the levels of TNF-α were also present between the three groups and between different intervals(P<0.01). The significant differences in SP-A mRNA and SP-B mRNA amplification ratio were seen between the three groups at the same intervals(P<0.01), but the differences between different intervals in the PQ group were statistically significant(P<0.05). The differences between different intervals in the LA group were statistically significant(P<0.01).CONCLUSION: Lipoic acid in acute paraquat poisoning could diminish lung tissue damage by regulating directly tumor necrosis factor and indirectly the content of pulmonary surfactant so as to reduce pulmonary edema, improve lung compliance, and finally protect lung tissues.

Autotaxin and lysophosphatidic acid signalling in lung pathophysiology

Autotaxin(ATX or ENPP2) is a secreted glycoprotein widely present in biological fluids. ATX primarily functions as a plasma lysophospholipase D and is largely responsible for the bulk of lysophosphatidic acid(LPA) production in the plasma and at inflamed and/or malignant sites. LPA is a phospholipid mediator produced in various conditions both in cells and in biological fluids, and it evokes growth-factor-like responses, including cell growth, survival, differentiation and motility, in almost all cell types. The large variety of LPA effector functions is attributed to at least six G-protein coupled LPA receptors(LPARs) with overlapping specificities and widespread distribution. Increased ATX/LPA/LPAR levels have been detected in a large variety of cancers and transformed cell lines, as well as in non-malignant inflamed tissues, suggesting a possible involvement of ATX in chronic inflammatory disorders and cancer. In this review, we focus exclusively on the role of the ATX/LPA axis in pulmonary pathophysiology, analysing the effects of ATX/LPA on pulmonary cells and leukocytes in vitro and in the context of pulmonary pathophysi-ological situations in vivo and in human diseases.

14,15-EET减轻脂多糖诱导的小鼠急性肺损伤的作用及其机制

目的探讨14,15-环氧二十碳三烯酸(14,15-EET)减轻脂多糖(LPS)诱导小鼠急性肺损伤(ALI)的作用及其机制。方法将32只6~8周的C57BL/6J雄性小鼠按照随机数字表法分为4组:对照组、LPS组、LPS+铁死亡抑制剂(Fer-1)组以及LPS+14,15-EET组,每组各8只。对照组小鼠气管内滴注无菌磷酸盐缓冲液(PBS)50μL,另外3组小鼠气管内分别滴注0.2 mg/mL LPS 50μL。气管内滴注LPS刺激6 h后,LPS+Fer-1组尾静脉注射Fer-1(0.8 mg/kg),LPS+14,15-EET组尾静脉注射14,15-EET(100 nmol/L),分别作用16 h。造模成功后取小鼠肺组织及支气管肺泡灌洗液(BALF),苏木精-伊红染色观察各组小鼠肺组织病理学变化,测量肺湿/干(W/D)比重;记录各组小鼠BALF中总蛋白浓度及总细胞数量;采用实时荧光定量聚合酶链式反应(RT-qPCR)检测小鼠肺组织白细胞介素(IL)-1β和单核细胞趋化蛋白-1(MCP-1)mRNA表达;采用冰冻切片活性氧簇(ROS)染色观察肺组织中ROS的生成;分别使用试剂盒检测肺组织丙二醛水平及铁含量;采用蛋白质印迹法检测铁死亡相关分子谷胱甘肽过氧化物酶4(GPX4)、环氧化物酶2(COX2)的表达水平。结果与对照组相比,LPS组肺损伤评分及W/D值均明显升高,差异均有统计学意义(P<0.05);与LPS组相比,LPS+Fer-1组和LPS+14,15-EET组肺损伤评分及W/D值均明显下降,差异均有统计学意义(P<0.05)。与对照组相比,LPS组BALF中总蛋白浓度、细胞数量明显升高,肺组织中IL-1β和MCP-1 mRNA表达水平均明显升高,差异均有统计学意义(P<0.05);与LPS组相比,LPS+Fer-1组和LPS+14,15-EET组BALF蛋白、细胞的数量及肺组织中IL-1β和MCP-1表达均明显下降,差异均有统计学意义(P<0.05)。与对照组相比,LPS组ROS红色荧光信号明显增强,丙二醛、铁离子、COX2水平均显著升高,GPX4水平下降,差异均有统计学意义(P<0.05);与LPS组相比,LPS+Fer-1组和LPS+14,15-EET组肺组织中ROS红色荧光信号明显减弱,丙二醛、铁离子、COX2水平显著降低,GPX4水平升高,差异均有统计学意义(P<0.05)。LPS+Fer-1组和LPS+14,15-EET组以上各指标比较,差异均无统计学意义(P>0.05)。结论14,15-EET可能通过抑制铁死亡减轻LPS诱导的小鼠ALI,发挥肺部保护作用。

重组人白细胞介素35早期干预对脂多糖诱导大鼠急性肺损伤的保护作用研究

目的探讨重组人白细胞介素35(interleukin 35,IL-35)早期干预对脂多糖(lipopolysaccharide,LPS)诱导的大鼠急性肺损伤(acute lung injury,ALI)的保护作用。方法采用随机数字表法将40只雄性SD大鼠分成正常组、致伤组、对照组和治疗组,每组各10只(其中每个观察点5只)。正常组大鼠不作处理,其余3组大鼠麻醉后经暴露的气管滴注10 mg/kg LPS建立大鼠ALI模型。造模后,治疗组大鼠尾静脉注射重组人IL-352μg,每天给药1次,连续给药3天;对照组大鼠尾静脉注射同等剂量无菌生理盐水,每天1次,连续3天;正常组和致伤组大鼠不进行药物干预。观察各组大鼠干预后第1、3天肺组织病理学变化及评分、动脉血氧分压(arterial partial pressure of oxygen,PaO_(2))和二氧化碳分压(partial pressure of carbon dioxide,PCO_(2))变化。采用酶联免疫吸附分析(enzyme-linked immunosorbent assay,ELISA)法检测大鼠肺组织匀浆上清液中肿瘤坏死因子α(tumor necrosis factor alpha,TNF-α)和白细胞介素10(interleukin 10,IL-10)含量。结果与正常组比较,致伤组、对照组和治疗组大鼠建模后第1天的肺组织病理评分均显著升高、PaO_(2)显著降低(P均<0.05);治疗组大鼠第3天肺组织病理评分显著低于致伤组和对照组、PaO_(2)显著高于致伤组和对照组,致伤组、对照组和治疗组大鼠第3天PCO_(2)较正常组显著升高(P均<0.05)。与正常组相比,致伤组、对照组和治疗组大鼠第1、3天TNF-α、IL-10含量明显升高(P均<0.05);治疗组大鼠第1、3天TNF-α含量明显低于对照组(P均<0.05),第1天IL-10含量明显低于致伤组和对照组,但第3天IL-10含量明显高于致伤组和对照组(P均<0.05)。结论重组人IL-35具有减轻LPS致大鼠肺损伤的作用,可降低肺损伤组织TNF-α水平,提高IL-10水平的作用。

避瘟解毒颗粒对LPS诱导急性肺损伤小鼠保护作用的研究

探究避瘟解毒颗粒对脂多糖(LPS)致急性肺损伤(ALI)小鼠的保护作用。将30只C57小鼠随机分为正常组、模型组、地塞米松组、避瘟解毒颗粒高、低剂量组,每组6只,每天给药1次,连续给药7 d。模型组、地塞米松组、避瘟解毒颗粒给药组气管滴注脂多糖(LPS)构建小鼠急性肺损伤模型(ALI)。造模后72 h取材检测,分析小鼠体重变化情况;血常规指标;胸腺指数;ELISA法检测肺泡灌洗液(BALF)中IL-1β、IL-6、TNF-α水平;HE染色法观察肺组织病理变化。与模型组比较,避瘟解毒颗粒高剂量组小鼠血清中血常规指标,BALF中炎性细胞因子IL-6、TNF-α含量,肺组织损伤程度均有不同程度的降低(P<0.05,P<0.01),且高剂量组能显著升高ALI小鼠的胸腺指数(P<0.01)。避瘟解毒颗粒对LPS诱导急性肺损伤发挥一定的保护作用,改善小鼠肺组织的病理改变,增强免疫功能,其作用机制可能与抑制促炎细胞因子的分泌及发挥抗炎作用有关。

肺超声评分评估油酸致山羊急性肺损伤的实验研究

目的 探讨肺超声评分(LUS)对油酸致山羊急性肺损伤(ALI)的诊断价值。方法 将16只山羊随机分为轻伤组和重伤组,每组各8只,通过耳缘静脉分别注射不同剂量油酸(轻伤组0.05 ml/kg,重伤组0.10 ml/kg),建立相应ALI模型。以山羊双侧胸壁第5肋为界分为左上、左下、右上及右下4个肺区,于致伤前和致伤后1 h、3 h、6 h动态观察两组山羊全肺及各肺区超声表现,比较两组LUS的差异;绘制受试者工作特征(ROC)曲线分析致伤后1 h、3 h、6 h全肺及各肺区LUS预测山羊ALI严重程度的诊断价值。通过血气分析和炎症因子检测分别获得各时间点动脉血气指标[氧分压(PaO_(2))、氧饱和度(SaO_(2))、氧合指数(PaO_(2)/FiO_(2))]和肿瘤坏死因子-α(TNF-α),比较两组上述指标的差异。然后处死山羊,观察肺大体损伤情况,取肺组织行病理组织学检查并进行病理损伤评分,计算肺湿干比,分析全肺及各肺区LUS与肺湿干比、病理损伤评分的相关性。结果 轻伤组1只山羊于致伤后5 h死亡,余山羊均成功建立油酸诱导ALI模型。(1)各ALI模型致伤后全肺LUS随着时间增加呈逐渐上升趋势,重伤组致伤后1 h、3 h、6 h全肺LUS均高于轻伤组,差异均有统计学意义(均P<0.05)。两组致伤后1 h、3 h、6 h右下肺LUS比较差异均有统计学意义(均P<0.05),其余肺区LUS比较差异均无统计学意义;重伤组致伤后6 h左下肺LUS高于左上肺,致伤后3 h、6 h右下肺LUS均高于右上肺,差异均有统计学意义(均P<0.05);轻伤组致伤后同一时间点各肺区LUS比较差异均无统计学意义。(2)ROC曲线分析显示,致伤后各时间点全肺LUS预测山羊ALI严重程度的曲线下面积(AUC)均>0.8;各时间点右下肺LUS预测山羊ALI严重程度的AUC均>0.9,其中致伤后1 h右下肺LUS的预测效能最高(AUC=0.938)。(3)重伤组致伤后3 h、6 h PaO_(2)、SaO_(2)、PaO_(2)/FiO_(2)均低于轻伤组,差异均有统计学意义(均P<0.05)。轻、重伤组致伤后TNF-α随着时间增加均呈逐渐上升趋势,但与致伤前比较差异均无统计学意义。(4)重伤组肺湿干比和全肺病理损伤评分均高于轻伤组[7.36±0.97 vs. 5.86±0.50,(17.63±3.15)分vs.(13.86±4.07)分],差异均有统计学意义(均P<0.05);重伤组左下肺病理损伤评分高于左上肺,右下肺病理损伤评分高于右上肺,差异均有统计学意义(均P<0.05);轻伤组右下肺病理损伤评分高于右上肺,差异有统计学意义(P<0.05)。(5)相关性分析显示,致伤后6 h全肺、左下肺、右上肺及右下肺LUS均与肺湿干比呈正相关(均P<0.05),尤以右下肺LUS的相关性最高;致伤后6 h全肺、左下肺及右下肺LUS均与病理损伤评分呈正相关(均P<0.05),尤以右下肺LUS的相关性最高。结论 应用LUS可准确评估山羊ALI早期严重程度和变化,具有一定的诊断价值;不同肺区LUS存在差异,其中右下肺LUS与其严重程度的相关性最高。

灵芝酸A对脂多糖诱导的小鼠急性肺损伤的改善作用及机制

目的探讨灵芝酸A(ganoderic acid A,GAA)对脂多糖(lipopolysaccharides,LPS)诱导急性肺损伤(acute lung injury,ALI)小鼠的影响及作用机制。方法将小鼠随机分为对照组、模型组、低剂量GAA组(GAA-L组)、高剂量GAA组(GAA-H组),每组12只。气管内滴注LPS(5 mg·kg^(-1))构建ALI小鼠模型,GAA-L组和GAA-H组小鼠分别在ALI造模前30 min腹腔注射50或150 mg·kg^(-1)GAA。造模后12 h,收集肺泡灌洗液(BALF),计数BALF中总细胞和中性粒细胞含量并检测TNF-α和IL-1β含量。收集肝脏,称重法获取肺湿重/干重比值,HE染色观察肺组织形态学表现,检测肺组织中MDA、ROS、GSH和SOD水平,免疫荧光染色检测肺组织中CD31和VCAM-1表达,Western blot法检测肺组织中NLRP3、ASC、Caspase-1、GSDMD蛋白表达。结果与模型组比较,低和高剂量GAA组小鼠肺组织ALI评分和肺组织的湿/干重比均降低(P<0.05),病理损伤减轻,BALF中总细胞、中性粒细胞、IL-1β、TNF-α含量均下降(P<0.05),肺组织中MDA、NLRP3、ASC、caspase-1、GSDMD蛋白表达均下调(P<0.05),GSH和SOD水平升高(P<0.05),且高剂量组的效果显著优于低剂量组(P<0.05)。结论GAA对ALI小鼠具有肺保护作用,其机制可能与其抑制NLRP3/GSDMD信号通路,减轻炎症反应、降低氧化应激和抑制细胞焦亡有关。