Acute Lung Injury Group Research Articles

Role of Nrf2 signaling pathway in endoplasmic reticulum stress response during lipopolysaccharide-induced acute lung injury in mice

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in endoplasmic reticulum stress response during lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Methods Forty clean-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 22-26 g, were divided into 4 groups (n=10 each) using a random number table method: control group (group C), group ALI, salubrinal group (group S) and salubrinal plus brusatol group (group S+ B). Animals were intratracheally instilled with 5 mg/kg of LPS diluted in normal saline to establish the model of ALI.Animals were intratracheally instilled with 100 μl of normal saline in group C. Mice in group S were intraperitoneally injected with endoplasmic reticulum stress response inhibitor 1 mg/kg salubrinal at 1 and 24 h after LPS instillation.Mice of group S+ B were intraperitoneally injected with brusatol 2 mg/kg once every other day for 10 days prior to LPS instillation, and the other treatments were similar to those previously described in group S. Mice were sacrificed at 48 h after LPS administration, and lungs were removed for microscopic examination of the pathological changes of lung tissues which were scored and for determination of contents of IL-17A, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in lung tissues (by enzyme-linked immunosorbent assay) and expression of Nrf2, CCAAT/enhancer-binding protein homologous protein (CHOP) and caspase-12 in lung tissues (by Western blot). Lung water content was calculated. Results Compared with group C, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of CHOP and caspase-12 in cytoplasma was up-regulated, and the expression of Nrf2 in nuclei was down-regulated in ALI and S+ B groups, and the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of Nrf2 in nuclei and CHOP in cytoplasma was up-regulated, and the expression of caspase-12 was down-regulated in group S (P<0.05). Compared with group ALI, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly decreased, the expression of CHOP and caspase-12 in cytoplasma was down-regulated, the expression of Nrf2 in nuclei was up-regulated (P<0.05), and the pathological changes were significantly attenuated in group S. Compared with group S, the lung water content and contents of IL-17A, TNF-α and IL-6 were significantly increased, the expression of CHOP and caspase-12 in cytoplasma was up-regulated, the expression of Nrf2 in nuclei was down-regulated (P<0.05), and the pathological changes of lung tissues were accentuated in group S+ B. Conclusion Nrf2 signaling pathway is involved in the process of endoplasmic reticulum stress response during LPS-induced ALI in mice. Key words: NF-E2-related factor 2; Endotoxins; Acute lung injury; Endoplasmic reticulum stress

Prospective Single-Arm Trial of Endovascular Mechanical Debulking as Initial Therapy in Patients With Acute and Subacute Lower Limb Ischemia: One-Year Outcomes

Purpose: To report the results of a prospective, single-arm study to establish whether the initial treatment of acute or subacute limb ischemia (ALI and SLI, respectively) can be accomplished successfully using endovascular mechanical debulking of the target vessels to avoid the risks associated with thrombolysis and/or open surgery. Materials and Methods: From April 2009 to April 2015, 316 consecutive patients (mean age 70.9±12 years; 184 men) with ALI (202, 63.9%) or SLI (114, 36.1%) were enrolled; the only exclusion criterion was irreversible ischemia. The ALI group included 146 (72.3%) participants with category IIb ischemia and 56 (27.7%) with category IIa. Critical limb ischemia was diagnosed in 74 (64.9%) of the 114 patients with SLI. Target occlusions of thrombotic (n=256) or embolic (n=60) origin were located in the femoropopliteal segment (n=231), prosthetic or venous femoropopliteal bypass grafts (n=75), and the aortoiliac segment (n=35). The mean occlusion length was 22.9±14.8 cm. Results: The overall technical success (residual stenosis ≤30%) was 100% after debulking and adjunctive techniques (aspiration, dilation, stenting) at the level of the target lesions. No open surgical or thrombolytic modalities were necessary to bypass or recanalize the target vessels, and no death occurred in association with target occlusion therapy. Additional infrapopliteal interventions were performed in 195 (61.7%) patients (adjunctive thrombolysis in 29) to treat acute, subacute, and chronic lesions. Minor complications directly related to the debulking procedure occurred in 26 (8.2%) patients. Serious complications occurred in 11 (3.5%) patients, including hemorrhage in 8 (2.5%) patients (associated with infrapopliteal thrombolysis in 5). At 30 days, primary and secondary patency rates were 94.3% and 97.2%, respectively; mortality was 0.3% (1 fatal intracranial hemorrhage after adjunctive thrombolysis). Of 229 patients eligible for 1-year follow-up, amputation-free survival was estimated to be 87.4% in 199 patients with available data. Conclusion: In this all-comers study, mechanical debulking with the Rotarex alone or with adjunctive techniques is feasible as a primary therapy for occluded supratibial vessels in patients with ALI or SLI.

Contributing factors in the development of acute lung injury in a murine double hit model.

Blunt chest (thoracic) trauma (TxT) is known to contribute to the development of secondary pulmonary complications. Of these, acute lung injury (ALI) is common especially in multiply injured patients and might not only be due to the direct trauma itself, but seems to be caused by ongoing and multifactorial inflammatory changes. Nevertheless, the exact mechanisms and contributing factors of the development of ALI following blunt chest trauma are still elusive. 60 CL57BL/6N mice sustained either blunt chest trauma combined with laparotomy without further interventions or a double hit (DH) including TxT and cecal ligation puncture (CLP) after 24h to induce ALI. Animals were killed either 6 or 24h after the second procedure. Pulmonary expression of inflammatory mediators cxcl1, cxcl5, IL-1β and IL-6, neutrophil infiltration and lung tissue damage using the Lung Injury Score (LIS) were determined. Next to a moderate increase in other inflammatory mediators, a significant increase in CXCL1, neutrophil infiltration and lung injury was observed early after TxT, which returned to baseline levels after 24h. DH induced significantly increased gene expression of cxcl1, cxcl5, IL-1β and IL-6 after 6h, which was followed by the postponed significant increase in the protein expression after 24h compared to controls. Neutrophil infiltration was significantly enhanced 24h after DH compared to all other groups, and exerted a slight decline after 24h. LIS has shown a significant increase after both 6 and 24h compared to both control groups as well the late TxT group. Early observed lung injury with moderate inflammatory changes after blunt chest trauma recovered quickly, and therefore, may be caused by mechanical lung injury. In contrast, lung injury in the ALI group did not undergo recovery and is closely associated with significant changes of inflammatory mediators. This model may be used for further examinations of contributing factors and therapeutic strategies to prevent ALI.

Oxygenation impairment in patients with acute aortic dissection is associated with disorders of coagulation and fibrinolysis: a prospective observational study.

Stanford type-A acute aortic dissection (AAD) is typically accompanied by oxygenation impairment before surgery. In addition, inflammation, coagulation and fibrinolysis also impair blood oxygenation. However, our understanding of the concentration of these factors in bronchoalveolar lavage fluid (BALF) has not been reported. The objective of the study was to investigate the impact of preoperative acute lung injury (ALI) on postoperative oxygenation impairment and to explore the effect of coagulation and fibrinolysis in blood and BALF. This investigation utilized a prospective observational study design, which was registered at www.clinicaltrials.gov (identifier NCT01894334). The study included 53 patients undergoing surgery for Stanford type-A AAD at an academic hospital in China between October 2013 and July 2014. Preoperative ALI was identified according to the oxygenation index calculated by the PaO2/FiO2 ratio. The subjects were divided into the ALI group (oxygenation index ≤300 mmHg) or the control group (oxygenation index >300 mmHg). The primary outcome was patient oxygenation index, while secondary outcomes were concentrations of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibitor-1 (PAI-1) in serum and BALF. The incidence of preoperative ALI for Stanford type-A AAD patients was 41.5%. Stanford type-A AAD patients with preoperative ALI had a lower postoperative oxygenation index (104.6±31.7 vs. 248.7±48.0 mmHg, P<0.001), higher concentrations of TF in serum and BALF (F=133.67, P<0.001; F=68.14, P<0.001), higher concentrations of TFPI in serum and BALF (F=31.98, P<0.001; F=45.58, P<0.001), and higher concentrations of PAI-1 in serum and BALF (F=213.88, P<0.001; F=107.95, P<0.001) when compared with those without preoperative ALI. Type-A AAD patients also showed a greater loss of blood (1,524±458 vs. 1,175±327 mL, P=0.040), longer mechanical ventilation time in the ICU (27.24±8.37 vs. 17.33±7.36 h, P<0.001), longer total stay in the ICU (42.27±10.85 vs. 33.45±9.05 h, P=0.002), and longer total hospital stay (17.77±5.00 vs. 13.48±3.97 days, P=0.001). Multivariate linear regression analysis indicated that preoperative PAI-1 in BALF, and TF in both serum and BALF were significantly associated with preoperative oxygenation impairment in patients with Stanford type-A AAD. Preoperative ALI caused more serious postoperative oxygenation impairment for Stanford type-A AAD, and coagulation and fibrinolysis appear to play critical roles in this process. Preoperative PAI-1 in BALF and TF in both serum and BALF were significant factors related to the occurrence of preoperative oxygenation impairment for Stanford type-A AAD.

Role of Nrf2/HO-1 signaling pathway in bone marrow mesenchymal stem cells-induced reduction of endotoxin-induced acute lung injury in rats

Objective To evaluate the role of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in bone marrow mesenchymal stem cells (MSCs)-induced reduction of endotoxin-induced acute lung injury (ALI) in rats. Methods Thirty-two clean-grade healthy male Sprague-Dawley rats, weighing 180-250 g, were divided into 4 groups (n=8 each) using a random number table method: control group (group C), ALI group, MSCs group and brusatol plus MSCs group (group B+ MSCs). Lipopolysaccharide 20 mg/kg was intravenously infused to establish the model of acute lung injury. Phosphate buffered saline(PBS)1 ml was intravenously infused at 1 h after establishing the model in group ALI. The equal volume of sterile saline and PBS was given instead in group C. PBS (1 ml) containing MSCs 1×106 cells was intravenously infused at 1 h after establishing the model in group MSCs. Brusatol 0.4 mg/kg was intraperitoneally injected every other day during 10 days before establishing the model, and MSCs were given at 1 h after establishing the model in group B+ MSCs. Bronchoalveolar lavage fluid (BALF) was collected and lung tissues were removed at 6 h after establishing the model. The protein concentration and neutrophil count in BALF were determined, and the wet/dry weight ratio (W/D ratio) were calculated. The pathological changes of lung tissues were observed by hematoxylin-eosin staining. The expression of Nrf2 and HO-1 by Western blot, activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and content of malondialdehyde (MDA) were determined . Results Compared with group C, the W/D ratio and total cell count and protein concentration in BALF were significantly increased, the MPO activity was enhanced, the MDA content was increased, the SOD activity was weakened, and the expression of Nrf2 was up-regulated (P<0.05), and the pathological changes were accentuated in group ALI. Compared with group ALI, the W/D ratio and total cell count and protein concentration in BALF were significantly decreased, the MPO activity was weakened, the MDA content was decreased, the SOD activity was enhanced, and the expression of Nrf2 and HO-1 was up-regulated (P<0.05), and the pathological changes were significantly attenuated in group MSCs. Compared with group MSCs, the total cell count was significantly increased, the MPO activity was enhanced, the MDA content was increased, the expression of Nrf2 and HO-1 was down-regulated (P<0.05), and the pathological changes were accentuated in group B+ MSCs. Conclusion Nrf2/HO-1 signaling pathway is involved in bone marrow MSCs-induced reduction of endotoxin-induced acute lung injury in rats. Key words: NF-E2 related factor 2; Heme oxygenase-1; Mesenchymal stromal cells; Acute lung injury; Endotoxemia

Aucubin alleviates lipopolysaccharide-induced acute lung injury in mice

To investigate the effect of prophylactic aucubin (AU) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. Methods: Male BABL/c mice were randomly divided into a control group, an ALI group, and an AU treatment group, 16 mice in each group. ALI mice were injected with LPS (5 mg/kg, intratracheal injection), and AU (10 mg/kg) was injected intraperitoneally 30 min ahead. After LPS injection for 6 hours mice were sacrificed, the morphological changes of lung tissues were detected by HE staining and the lung injury score was obtained. The mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin 10 (IL-10) in lung tissue was detected by real-time PCR. The total protein and lactate dehydrogenase (LDH) activity, the cell count, and the protein content of TNF-α and IL-10 in the mouse bronchoalveolar lavage fluid (BALF) were detected. Results: Compared with ALI mice, the pathological damage score of lung tissue was significantly reduced in the AU group, the total number of BALF cells, neutrophils, and macrophages were significantly decreased, LDH activity and the total protein content were also significantly decreased (all P<0.01). In addition, AU can reduce the mRNA and protein expression of TNF-α in lung of ALI mice, and increase the mRNA and protein expression of IL-10 (all P<0.01). Conclusion: AU can reduce LPS-induced ALI in mice.

Effects of penehyclidine hydrochloride on Nrf2/ARE signaling pathway during endotoxin-induced acute lung injury in neonate rats

Objective: To evaluate the effects of penehyclidine hydrochloride on the nuclear factor erythroid 2-related factor 2/antioxidant responsive element (Nrf2/ARE) signaling pathway during endotoxin-induced acute lung injury(ALI) in neonate rats. Methods: Forty 7-day-old Wistar rats weighing 12-18 g were randomly divided into 4 groups (n=10) using a random number table: normal saline group(NS group), acute lung injury(ALI group), penehyclidine hydrochloride group(PHC group) and penehyclidine hydrochloride+ Nrf2 siRNA plasmid group(PNS group). The ALI model was induced with intraperitoneal endotoxin (5.0 mg/kg) in groups ALI, PHC and PNS. In groups PHC and PNS, penehyclidine hydrochloride (2.0 mg/kg) was injected intraperitoneally at 1 h before ALI respectively, while the equal volume of normal saline was administered in groups NS and ALI. The animal of PNS group were inhaled adenovirus packaging of Nrf2-siRNA three times (one time a day) before modeling. At 4 h after endotoxin injection, the rats were sacrificed. The lungs were collected to determine the wet/dry(W/D) lung weight ratio. The expression of Nrf2 and heme oxygen and enzyme 1(HO-1) were determined by Western blotting, contents of tumor necrosis factor-alpha(TNF-α),interleukin10 (IL-10)were determined by enzyme-linked immunosorbent assay(ELISA). The cell apoptosis were determined by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling(TUNEL),and the apoptotic index was calculated. Results: The W/D ratio in NS, ALI, PHC and PNS groups were (4.2±0.1), (9.6±0.7), (6.5±0.6), (8.3±1.3) respectively. The apoptotic index were (3.7±0.5)%, (31.5±3.2)%, (17.6±4.2)%, (28.1±3.5)%respectively.The contents of TNF-α were (10.3±1.6), (98.5±8.5), (68.5±6.7), (89.9±8.5) pg/ml respectively. The contents of IL-10 were (7.9±0.6), (102.8±9.3), (72.5±5.8), (97.7±9.1) pg/ml respectively.The expression of Nrf2 were (23.2±7.6), (79.8±13.0), (155.5±16.7), (12.0±3.3) respectively. The expression of HO-1 were (31.7±8.6), (90.8±10.3), (147.6±22.5), (61.4±9.7) respectively. There were statistically significant differences among different groups (F=86.013, 154.897, 328.810, 374.198, 333.965, 125.274, all P<0.05). Compared with group NS, the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 increased, the expression of Nrf2 and HO-1 up-regulated in group ALI and group PHC (all P<0.05). Compared with group ALI, the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 decreased, the expression of Nrf2 and HO-1 up-regulated in group PHC (all P<0.05). Compared with group ALI, no significant differences were found in the W/D ratio, apoptotic index and the contents of TNF-α, IL-10 in group PNS(all P>0.05), while the expression of Nrf2 and HO-1 down-regulated in group PNS (all P<0.05). Compared with group PHC, the W/D ratio,apoptotic index and the contents of TNF-α,IL-10 increased, the expression of Nrf2 and HO-1 down-regulated in group PNS (all P<0.05). Conclusion: Nrf2/ARE signaling pathway is involved in the reduction of ALI by penehyclidine hydrochloride in neonate rats.

Effect of bone marrow-derived mesenchymal stem cells on TGF-β1/Smad signaling pathway during acute lung injury in rats

Objective To evaluate the effect of bone marrow-derived mesenchymal stem cells(BMSCs)on transforming growth factor-β1(TGF-β1)/Smad signaling pathway during acute lung injury(ALI)in rats. Methods Healthy clean-grade adult male Sprague-Dawley rats, aged 4-5 weeks, weighing 100-120 g, were selected, and BMSCs were prepared and cultured in vitro.Eighty-four healthy clean-grade adult male Sprague-Dawley rats, aged 4 weeks, weighing 170-190 g, were selected and divided into 4 groups(n=21 each)using a random number table method: control group(group C), group ALI, ALI plus BMSCs group(group ALI+ BMSCs), and ALI plus phosphate buffer solution(PBS)group(group ALI+ PBS). ALI was induced by intraperitoneally injecting 5 mg/kg lipopolysaccharide 0.5 ml in anesthetized rats.In group ALI+ BMSCs, 1×104 cells/ml BMSCs 0.5 ml(in PBS)was injected via the tail vein after intraperitoneal injection of lipopolysaccharide.PBS 0.5 ml was injected via the tail vein after intraperitoneal injection of lipopolysaccharide in group ALI+ PBS.Arterial blood samples were collected at 6, 24 and 48 h after injecting BMSCs for blood gas analysis and for determination of wet to dry weight ratio(W/D ratio), pathological changes(using haematoxylin and eosin staining), and expression of TGF-β1, Smad2 and Smad3 in lung tissues(by Western blot). Results Compared with group C, PaO2 was significantly decreased, PaCO2 and W/D ratio were increased, the expression of TGF-β1, Smad2 and Smad3 in lung tissues was up-regulated(P<0.05), and the pathological changes of lung tissues were accentuated in ALI, ALI+ BMSCs and ALI+ PBS groups.Compared with group ALI, PaO2 was significantly increased, PaCO2 and W/D ratio were decreased, the expression of TGF-β1, Smad2 and Smad3 in lung tissues was down-regulated(P<0.05), and the pathological changes of lung tissues were significantly reduced in group ALI+ BMSCs. Conclusion The mechanism by which BMSCs mitigates ALI may be associated with inhibiting TGF-β1/Smad signaling pathway in rats. Key words: Mesenchymal stem cell transplantation; Transforming growth factor beta 1; Smad Proteins; Respiratory distress syndrome, adult

Autophagy Activation Improves Lung Injury and Inflammation in Sepsis.

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) undergoes the process of pathological event including lung tissue dysfunction, pulmonary edema, and inflammation in sepsis. Autophagy is a cytoprotective process recognized as one of the major pathways for degradation and recycling of cellular constituents. Autophagy as a protective or maladaptive response was still confused in ALI during sepsis. Acute lung injury was performed by cecal ligation and puncture (CLP). Autophagic inducer rapacymin and inhibitor 3-MA and autophagosomal-lysosome fusion inhibitor bafilomucin (Baf) A1 and chloroquine (CQ) were administrated by intraperitoneal injection at 1h after CLP operation. Microtubule-associated protein light chain 3 II (LC3II), Beclin 1, Rab7, and lysosome-associated membrane protein type 2 (LAMP2) were detected by western blotting. Seven-day survival rate of septic mice was observed. Histologic scores, lung wet-to-dry (W/D) weight ratio, oxygenation index (PaO2/FiO2), total cells and polymorphonuclear neutrophils (PMN) in bronchial alveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity and cytokine tumor necrosis factor (TNF)-α, high-mobility group box (HMGB)1, interleukin (IL)-6, IL-10, and monocyte chemotactic protein (MCP)1 were measured after sham or ALI operation. ALI induced the increasing expression of autophagy-related protein LC3II, Beclin 1, Rab7, and LAMP2 in CLP operation. Autophagic inducer rapacymin significantly induced the expression of LC3II, Beclin 1, LAMP2, and Rab7 in mice model of CLP, and inhibitor 3-MA reduced expression of LC3II, Beclin 1, LAMP2, and Rab7 expressions in CLP + RAP mice compared to CLP group. Compared with ALI group, Baf and CQ obviously elevated the level of LC3II and Beclin 1, and reduced the LAMP2 and Rab7 expressions in CLP + Baf group and ALI + CQ group. Compared with CLP group, autophagic inducer rapacymin improved the survival rate, histologic scores, lung wet/dry weight ratio, PaO2/FiO2, total cells, and PMNS in BALF and MPO activity and cytokines TNF-α, HMGB1, IL-6, IL-10, and MCP1 in CLP + RAP group, but there were exacerbated above indicators in CLP + 3-MA group, CLP + Baf group, and CLP + CQ group. Autophagy activation participated in the pathophysiologic process of sepsis, and alleviated the cytokine excessive release and lung injury in sepsis.

Relationship between α7nAChR signaling pathway and regulatory T cells during vagus nerve stimulation-induced reduction of endotoxin-caused acute lung injury in mice

Objective To evaluate the relationship between α7 nicotinic acetylcholine receptor (α7nAChR) signaling pathway and regulatory T cells (Tregs) during vagus nerve stimulation-induced reduction of endotoxin-caused acute lung injury (ALI) in mice. Methods Clean-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 22-25 g, were divided into 5 groups (n=10 each) using a random number table method: control group (group C), group ALI, vagus nerve stimulation group (group VNS), α-BGT group (group α-BGT) and vagus nerve stimulation plus α-BGT group (group VNS + α-BGT). After successful establishment of the model, the vagus nerve was stimulated for 30 s with a stimulus intensity of 0.5 mA, frequency of 20 Hz, an interval of 5 min, 60 min in total.Sterile normal saline 100 μl was injected into the trachea, and the vagus nerve was only exposed but not stimulated in group C. In group ALI, the ALI model was established, and the vagus nerve was isolated but not stimulated.In group α-BGT, α-BGT 1 μg/kg was intraperitoneally injected, the ALI model was established 1 h later, and the vagus nerve was isolated but not stimulated.In group VNS+ α-BGT, α-BGT 1 μg/kg was intraperitoneally injected, the ALI model was established 1 h later, and the vagus nerve was stimulated at 1 h after the end of establishment.Animals were sacrificed at 72 h after establishing the model, and lungs were removed for determination of lung water content, percentage of Tregs (using flow cytometry), myeloperoxidase (MPO) activity (by colorimetric assay), expression of α7nAChR (by Western blot) and contents of interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and IL-1β (by enzyme-linked immunosorbent assay). Results Compared with group C, the lung water content, MPO activity and IL-1β content were significantly increased in the other four groups, the expression of α7nAChR was significantly down-regulated in ALI, α-BGT and VNS+ α-BGT groups, the percentage of Tregs was significantly increased in group VNS, the IL-10 content was significantly decreased in ALI and α-BGT groups and increased in VNS and VNS+ α-BGT groups, and TGF-β contents were significantly decreased in ALI, α-BGT and VNS+ α-BGT groups and increased in group VNS (P<0.05). Compared with group ALI, the lung water content, MPO activity and IL-1β content were significantly decreased, the expression of α7nAChR was up-regulated, and the percentage of Tregs and contents of IL-10 and TGF-β were increased in group VNS, and the TGF-β content in group α-BGT and contents of IL-10 and TGF-β in group VNS+ α-BGT were significantly increased (P<0.05). Compared with group VNS, the lung water content, MPO activity and IL-1β content were significantly increased, the expression of α7nAChR was down-regulated, and the percentage of Tregs and contents of IL-10 and TGF-β were decreased in α-BGT and VNS+ α-BGT groups (P<0.05). The contents of IL-10 and TGF-β were significantly higher in group VNS+ α-BGT than in group α-BGT (P<0.05). Conclusion Vagus nerve stimulation can activate α7nAChR signaling pathway and raise the percentage of Tregs, thus reducing ALI in mice. Key words: Vagus nerve; Respiratory distress syndrome, adult; T-Lymphocytes, regulatory; Receptors, nicotinic

Cytokine profile in prediction of acute lung injury in patients with acute pancreatitis

ObjectivesTo study the role of cytokines in prediction of acute lung injury (ALI) in acute pancreatitis. MethodsLevels of TNFα, IL-6, IL-10, IL-8 and IL-1β were measured in 107 patients at presentation and at 72 h in patients who developed acute lung injury. A model was devised to predict development of ALI using cytokine levels and SIRS score. ResultsThe levels of TNF α (p < 0.0001), IL-6 (p < 0.0001), IL-8 (p < 0.0001) and IL-1β (p < 0.0001) were significantly higher in the ALI group. IL-10 levels were significantly lower in persistent ALI (p-ALI) than in transient ALI (t-ALI) patients (p < 0.038). p-ALI group had significant rise of TNFα (p = 0.019) and IL-1β (p = 0.001) while t-ALI group had significant rise of only IL-1β (p = 0.044) on day 3 vs day 1. Combined values of IL-6 and IL-8 above 251 pg/ml had sensitivity of 90.9% and a specificity of 100% to predict future development of ALI. Composite marker-I (IL6 ≥ 80 pg/ml + SIRS) yielded sensitivity and specificity of 73% and 98% whereas composite marker-II (IL8 ≥ 100 pg/ml + SIRS) yielded sensitivity and specificity of 73% and 95% to predict future ALI. ConclusionsIL-6 and IL-8 can predict future development of ALI. When they are combined with SIRS, they can be used as comprehensive composite markers.

Low-power laser alters mRNA levels from DNA repair genes in acute lung injury induced by sepsis in Wistar rats.

Acute lung injury (ALI) is defined as respiratory failure syndrome, in which the pathogenesis could occur from sepsis making it a life-threatening disease by uncontrolled hyperinflammatory responses. A possible treatment for ALI is the use of low-power infrared lasers (LPIL), whose therapeutical effects depend on wavelength, power, fluence, and emission mode. The evaluation mRNA levels of repair gene related to oxidative damage after exposure to LPIL could provide important information about the modulation of genes as treatment for ALI. Thus, the aim of this study was to evaluate the mRNA levels from OGG1, APEX1, ERCC2, and ERCC1 genes in lung tissue from Wistar rats affected by ALI and after exposure to LPIL (808nm; 100mW). Adult male Wistar rats (n = 30) were randomized into six groups (n = 5, for each group): control, 10J/cm2 (2J), 20J/cm2 (5J), ALI, ALI + LPIL 10J/cm2 and ALI + LPIL 20J/cm2. ALI was induced by intraperitoneal E. coli lipopolysaccharide injection (10mg/kg). Lungs were removed, and samples were withdrawn for total RNA extraction, cDNA synthesis, and mRNA levels were evaluated by RT-qPCR. Data normality was verified by Kolmogorov-Smirnov, comparisons among groups were by Student's t test, Mann-Whitney test, one-way ANOVA, Kruskal-Wallis followed by post-tests. Data showed that OGG1 (0.39 ± 0.10), ERCC2 (0.67 ± 0.24), and ERCC1 (0.60 ± 0.19) mRNA levels are reduced in ALI group when compared with the control group (1.00 ± 0.07, 1.03 ± 0.25, 1.01 ± 0.16, respectively) and, after LPIL, mRNA relative levels from DNA repair genes are altered when compared to non-exposed ALI group. Our research shows that ALI alter mRNA levels from genes related to base and nucleotide excision repair genes, suggesting that DNA repair is part of cell response to sepsis, and that photobiomodulation could modulate the mRNA levels from these genes in lung tissue.

Anti-inflammatory Role of Mesenchymal Stem Cells in an Acute Lung Injury Mouse Model.

Background Mesenchymal stem cells (MSCs) attenuate injury in various lung injury models through paracrine effects. We hypothesized that intratracheal transplantation of allogenic MSCs could attenuate lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice, mediated by anti-inflammatory responses.Methods Six-week-old male mice were randomized to either the control or the ALI group. ALI was induced by intratracheal LPS instillation. Four hours after LPS instillation, MSCs or phosphate-buffered saline was randomly intratracheally administered. Neutrophil count and protein concentration in bronchoalveolar lavage fluid (BALF); lung histology; levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and macrophage inflammatory protein-2; and the expression of proliferation cell nuclear antigen (PCNA), caspase-3, and caspase-9 were evaluated at 48 hours after injury.Results Treatment with MSCs attenuated lung injury in ALI mice by decreasing protein level and neutrophil recruitment into the BALF and improving the histologic change. MSCs also decreased the protein levels of proinflammatory cytokines including IL-1β, IL-6, and TNF-α, but had little effect on the protein expression of PCNA, caspase-3, and caspase-9.Conclusions Intratracheal injection of bone marrow-derived allogenic MSCs attenuates LPS-induced ALI via immunomodulatory effects.

Characteristics of pulmonary function and pathological changes following acute lung injury in rats

Objective To investigate the characteristics of pulmonary function and pathological changes in rats with acute lung injury (ALI) and provide experimental basis for further study on the mechanism of ALI. Methods Twenty five male SD rats were randomly divided into the control group (n=5) and acute lung injury (ALI) group (n=20). Lipopolysaccharide (LPS) (4.5 mg/kg) were injected into the ALI group rats to establish the ALI rat model. The rats in control group were given 150 μl isotonic saline. At 12, 24, 48, and 72 hours after injury, lung function of the rats were tested by Buxco small animal lung function test system, including the dynamic lung compliance (Cdyn), forced vital capacity (FVC), functional residual gas (FRC), quasi static compliance (Cchord), 100th millisecond expiratory volume (FEV100), and airway resistance (RI). In addition, the bronchoalveolar lavage fluid (BALF) was collected for detection of protein level and tumor necrosis factor (TNF-alpha) concentration. At the same time, the changes of lung tissues were recorded, and the pathological changes were observed by HE staining. Results Compared with the control group, Cdyn, FVC, FRC, and FEV100 in ALI group were significantly decreased at each time point after injury (P 0.05). The protein level and TNF-alpha concentration of BALF in ALI group were increased significantly (P<0.05 or <0.01) 12-72 hours after injury (P<0.01). Compared with the control group, the whole lung was dark red in ALI group 12 hours after injury, and the most serious bleeding occurred in the pulmonary hilum area with single or multiple hemorrhagic foci of different sizes. Multiple punctate and focal bleeding of different sizes were seen on the lung surface, which were radially distributed around the pulmonary hilum. The color of lung tissue was gradually restored to normal at 72 hours after injury. Under the light microscope, pulmonary interstitial edema, inflammatory cell infiltration, pulmonary vascular congestion and focal pulmonary hemorrhage were observed 12 h after injury, showing typical ALI pathological changes. The pathological changes were the most significant at 24 hours and reduced obviously at 72 hours. Conclusions A single intratracheal injection of LPS can induce typical ALI pathological changes. There is a similar trend between the pulmonary function indexes, lung pathology characteristics, and the protein level of BALF and proinflammatory cytokine level, suggesting that the pulmonary function test parameters can provide reference for evaluation of ALI. Key words: Lipopolysaccharide; Acute lung injuries; Respiratory function tests; Tumor necrosis factor α

Effects of low dose of aliskiren on isoproterenol-induced acute myocardial infarction in rats.

This study examined the effects of aliskiren (Ali) (direct renin inhibitor) on serum cardiac enzymes (LDH and CK-MB), electrocardiography (ECG) changes, myocardial oxidative stress markers (MDA, CAT, and GSH) and the expression of Bcl2, HO-1, and Nrf2 genes in isoproterenol (ISO)-induced myocardial infarction (MI). A total of 40 male albino rats were allocated into four groups, (1) normal control (NC) group, (2) Ali group (rats received Ali at 10mg/kg/day p.o. for 5days), (3) ISO group (rats received ISO 150mg/kg i.p. for two consecutive days at 24h intervals), and (4) Ali + ISO group (rats received ISO + Ali at 10mg/kg/day p.o. for 5 days from the 2nd dose of ISO). ISO group showed significant rise in serum cardiac enzymes (CK-MB and LDH), myocardial damage scores, myocardial MDA, HO-1, myocardial Nrf2 expression with significant reduction in myocardial antioxidants (CAT and GSH), and Bcl2 expression compared to the normal group (p < 0.05). ECG showed ST segment elevation, prolonged QT interval and QRS complex, and increased heart rate in ISO group. Co-administration of Ali and ISO caused significant increase in cardiac enzymes and morphology with increase in MDA, serum K, and creatinine with significant decrease in Bcl2, HO-1, and Nrf2 without significant changes in ECG parameters compared to ISO group. We concluded that low dose of Ali seems to exacerbate the myocardial injury in ISO-MI, which might be due to the enhanced oxidative stress and apoptosis.

Role of α7nAChR in electroacupuncture-induced reduction of acute lung injury induced by endotoxin in rats: the relationship with JAK2/STAT3 signaling pathway

Objective To evaluate the role of α7 nicotinic acetylcholine receptor (α7nAChR) in electroacupuncture (EA)-induced reduction of acute lung injury (ALI) induced by endotoxin and the relationship with Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) signaling pathway in rats. Methods Sixty clean-grade healthy male Sprague-Dawley rats, aged 8 weeks, weighing 200-220 g, were divided into 6 groups (n=10 each) using a random number table method: control group (group C), endotoxin-induced ALI group (group ALI), EA at acupoints plus ALI group (group EA), specific α7nAChR antagonist α-bungarotoxin (α-BGT) plus ALI group (group BA), EA at acupoints plus α-BGT plus ALI group (group EBA), and EA at non-acupoints plus ALI group (group SEA). ALI was induced by intravenously injecting lipopolysaccharide 5 mg/kg.EA stimulation of bilateral Zusanli and Neiguan acupoints was performed (frequency of disperse-dense wave 2/15 Hz, wave length 0.2-0.5 ms, intensity 1-2 mA) once a day (time for stimulation 9: 00 to 10: 00, 30 min per time) at 1-4 days before establishing the model in EA and EAB groups.EA was performed at the points 0.5 cm lateral to the acupoints of Zusanli and Neiguan with the same parameters of stimulation in group SEA.α-BGT 1 μg/kg was intraperitoneally injected at 30 min before establishing the model in BA and EBA groups.Rats were sacrificed at 6 h after injecting lipopolysaccharide, and lungs were removed for microscopic examination of the pathological changes which were scored and for determination of wet to dry weight ratio (W/D ratio), contents of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and IL-6 (by enzyme-linked immunosorbent assay), and expression of α7nAChR, phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) (by Western blot). Results Compared with group C, the lung injury scores, W/D ratio and contents of TNF-α, IL-1β and IL-6 were significantly increased, and the expression of α7nAChR, p-JAK2 and p-STAT3 was up-regulated in the other five groups (P 0.05). Compared with group EA, the lung injury scores, W/D ratio and contents of TNF-α, IL-1β and IL-6 were significantly increased, and the expression of α7nAChR, p-JAK2 and p-STAT3 was down-regulated in group EBA (P<0.05). Conclusion Up-regulated expression of α7nAChR activates JAK2/STAT3 signaling pathway, which is involved in EA-induced reduction of ALI in rats. Key words: Nicotinic; Electric stimulation therapy; Respiratory distress syndrome, adult; Janus kinase 2; Activating transcription factor 3

Effects of electroacupuncture on mitochondrial fusion-fission during endotoxin-induced acute lung injury in rabbits

Objective To evaluate the effect of electroacupuncture (EA) on mitochondrial fusion-fission during endotoxin-induced acute lung injury (ALI) in rabbits. Methods Sixty clean-grade New Zealand white rabbits, aged 2 months, weighing 1.5-2.0 kg, were divided into 4 groups (n=15 each) using a random number table: control group (group C), ALI group, EA at non-acupoint plus ALI group (group SEAM+ ALI) and EA at acupoint plus ALI group (group EAM+ ALI). Endotoxin-induced ALI was induced by injecting lipopolysaccharide 5 mg/kg (in 2 ml of 0.9% normal saline) via the auricular vein in ALI, SEAM+ ALI and EAM+ ALI groups.At 4, 3, 2 and 1 days and 30 min before lipopolysaccharide injection, bilateral Zusanli (ST36) and Feishu (BL13) acupoints were stimulated with an electric stimulator for 30 min in group EAM+ ALI, and EA was performed for 30 min at the points 1 cm lateral to the acupoints of Zusanli and Feishu in group SEAM+ ALI.The animals were sacrificed at 6 h after lipopolysaccharide injection and the lungs were removed for microscopic examination of the pathological changes (with a light microscope) and mitochondrial ultrastructure (with an electron microscope) and for determination of ROS and ATP contents and expression of Mfn1, Mfn2, optic atrophy 1(OPA1) and dynamin-related protein 1(Drp1) protein and mRNA in lung tissues (by real-time polymerase chain reaction or Western blot). Results Compared with group C, ATP content was significantly decreased, ROS content was increased, the expression of Mfn1, Mfn2 and OPA1 protein and mRNA was down-regulated, and the expression of Drp1 protein and mRNA was up-regulated in ALI, SEAM+ ALI and EAM+ ALI groups (P<0.05). Compared with group ALI, ATP content was significantly increased, the expression of Mfn1, Mfn2 and OPA1 protein and mRNA was up-regulated, and the expression of Drp1 protein and mRNA was down-regulated in SEAM+ ALI and EAM+ ALI groups, and ROS content was decreased in group EAM+ ALI (P<0.05). Compared with group SEAM+ ALI, ATP content was significantly increased, ROS content was decreased, the expression of Mfn1, Mfn2 and OPA1 protein and mRNA was up-regulated, and the expression of Drp1 protein and mRNA was down-regulated in group EAM+ ALI (P<0.05). Conclusion The mechanism by which EA mitigates endotoxin-induced ALI may be related to promoting mitochondrial fusion and inhibiting mitochondrial fission in rabbits. Key words: Electric stimulation therapy; Shock, septic; Respiratory distress syndrome, adult; Mitochondrial fusion; Mitochondrial fission

Protective effects of hyperbaric oxygen preconditioning against LPS-induced acute lung injury in rats

Introduction: Acute lung injury (ALI) is generally caused by oxidative damages and pulmonary overinflammations. Hyperbaric oxygen preconditioning (HBO2-PC) has been proven protective against oxidative-stress-related injuries. In this study, we investigated the effect of HBO2-PC on lipopolysaccharide (LPS)-induced ALI in rats. Methods: Thirty-two Sprague-Dawley rats randomly assigned into Sham, HBO2-PC, ALI and HBO2-PC+ALI groups (eight in each group) were sacrificed at 12 hours after the injection of LPS. The severity of ALI in rats was assessed in terms of histopathological changes in addition to wet/dry weight ratios. The levels of tumor necrosis factor-? (TNF-?), interleukin (IL)-6 and IL-1β in serum and lung homogenates were measured by enzyme-linked immunosorbent and qRT-PCR assays. Activities by hydrogen peroxide (H2O2), malondialdehyde (MDA), myeloperoxidase (MPO) as well as superoxide dismutase (SOD) in rat lungs were tested for neutrophil infiltration. Meanwhile the oxidative stress molecular markers nuclear factor-kappa B(NF-κB) p65 and nuclear factor erythroid 2-related factor 2 (Nrf2), together with its downstream heme-oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) were also quantified. Results: HBO2-PC significantly alleviated LPS-induced ALI, lowered the lung injury scores, reduced lung water content, and reduced H2O2, MDA levels as well as MPO activity, while simultaneously improving the arterial partial oxygen pressure (PaO2) and SOD activity. Furthermore, HBO2-PC inhibited the nuclear translocation of NF-κB p65 while enhancing the nuclear translocation of Nrf2, thus upregulating HO-1 and NQO1. Conclusions: Our results suggest that HBO2-PC was potentially protective for LPS-induced ALI lungs in rats, with a presumed mechanism that suppressed NF-κB while activating Nrf2. We propose that HBO2-PC should be considered a potential therapeutic strategy against ALI in rats.

Effect of bone marrow-derived mesenchymal stem cells on mTOR signaling pathways in lung tissues of rats with acute lung injury

Objective To evaluate the effect of bone marrow-derived mesenchymal stem cells (BMSCs) on mammalian target of rapamycin (mTOR) signaling pathways in lung tissues of rats with acute lung injury (ALI). Methods Healthy pathogen-free adult male Sprague-Dawley rats were selected, and the BMSCs were obtained and cultured in vitro.One hundred and five healthy clean adult male Sprague-Dawley rats, weighing 170-190 g, were divided into 5 groups (n=21 each) using a random number table: control group (group C), PBS group, group ALI, ALI plus BMSC group (group ALI+ BMSCs), and ALI plus phosphate buffer solution (PBS) group (group ALI+ PBS). Group C received no treatment.PBS 0.5 ml was injected via the tail vein in group PBS.Lipopolysaccharide (LPS, 0.5 ml) 5 mg/kg was intraperitoneally injected to establish the model of ALI in group ALI.BMSCs (0.5 ml) 1×104 cells/ml were injected via the tail vein after intraperitoneal injection of LPS in group ALI+ BMSCs.PBS 0.5 ml was injected via the tail vein after intraperitoneal injection of LPS in group ALI+ PBS.Arterial blood samples were collected for blood gas analysis at 6, 24 and 48 h after injection of BMSCs.Lungs were then removed for determination of wet/dry weight ratio (W/D ratio) and expression of mTOR, nuclear factor kappa B (NF-κB) and tumor necrosis factor-alpha (TNF-α) in lung tissues (by Western blot) and for examination of the pathologic changes of lungs tissues (using haematoxylin and eosin staining). Results Compared with group C, pH value and PaO2 were significantly decreased, PaCO2 and W/D ratio were increased, and the expression of mTOR, NF-κB and TNF-α was up-regulated at each time point in ALI, ALI+ BMSCs and ALI+ PBS groups (P<0.05). Compared with group ALI, pH value and PaO2 were significantly increased, PaCO2 and W/D ratio were decreased, the expression of mTOR, NF-κB and TNF-α was down-regulated at each time point (P<0.05), and the pathologic changes of lungs tissues were significantly attenuated in group ALI+ BMSCs. Conclusion The mechanism by which BMSCs reduce ALI may be associated with inhibiting mTOR signaling pathways in lung tissues of rats. Key words: Mesenchymal stem cell transplantation; Receptor-interacting protein serine-threonine kinases; Respiratory distress syndrome, adult

Effect of oxycodone on acute lung injury induced by lipopolysaccharide in rats

Objective To evaluate the effect of oxycodone on acute lung injury (ALI) induced by lipopolysaecharide (LPS) in rats. Methods Thirty-six pathogen-free healthy male Sprague-Dawley rats, weighing 250-300 g, were divided into 3 groups (n=12 each) using a random number table: sham operation group (group S), LPS-induced ALI group (group A) and oxycodone group (group O). ALI was induced by injecting LPS 8 mg/kg intravenously in A and O groups, while the equal volume of normal saline was given instead in group S. Oxycodone 2 mg/kg was injected intravenously at 10 min before LPS injection in group O, while the equal volume of normal saline was given instead in S and A groups.Rats were sacrificed at 6 h after LPS injection, and the broncho-alveolar lavage fluid (BALF) was collected for detection of tumor necrosis factor-alpha (TNF-α) and interleukin-1beta (IL-1β) concentrations by enzyme-linked immunosorbent assay.Pulmonary specimens were obtained for microscopic examination of the pathological changes and for determination of wet/dry weight ratio (W/D ratio) and expression of Toll-like receptor 4 (TLR4) in lung tissues (using real-time polymerase chain reaction and Western blot). Results Compared with group S, the TNF-α and IL-1β concentrations in BALF, W/D ratio, pathological scores and expression of TLR4 were significantly increased at 6 h after LPS injection in A and O groups (P<0.05). Compared with group A, the TNF-α and IL-1β concentrations in BALF, W/D ratio, pathological scores and expression of TLR4 were significantly decreased at 6 h after LPS injection in group O (P<0.05). Conclusion Oxycodone can attenuate LPS-induced ALI in lung tissues, and the mechanism is related to down-regulating the expression of TLR4 and inhibiting inflammatory responses of rats. Key words: Oxycodone; Endotoxemia; Respiratory distress syndrome, adult