Protective effects of the notoginsenoside R1 on acute lung injury by regulating the miR-128-2-5p/Tollip signaling pathway in rats with severe acute pancreatitis

Notoginsenoside R1 (NG-R1), the extract and the main ingredient of Panax notoginseng, has anti-inflammatory effects and can be used in treating acute lung injury (ALI). In this study, we explored the pulmonary protective effect and the underlying mechanism of the NG-R1 on rats with ALI induced by severe acute pancreatitis (SAP). MiR-128-2-5p, ERK1, Tollip, HMGB1, TLR4, IκB, and NF-κB mRNA expression levels were measured using real-time qPCR, and TLR4, Tollip, HMGB1, IRAK1, MyD88, ERK1, NF-κB65, and P-IκB-α protein expression levels using Western blot. The NF-κB and the TLR4 activities were determined using immunohistochemistry, and TNF-α, IL-6, IL-1β, and ICAM-1 levels in the bronchoalveolar lavage fluid (BALF) using ELISA. Lung histopathological changes were observed in each group. NG-R1 treatment reduced miR-128-2-5p expression in the lung tissue, increased Tollip expression, inhibited HMGB1, TLR4, TRAF6, IRAK1, MyD88, NF-κB65, and p-IκB-α expression levels, suppressed NF-κB65 and the TLR4 expression levels, reduced MPO activity, reduced TNF-α, IL-1β, IL-6, and ICAM-1 levels in BALF, and alleviated SAP-induced ALI. NG-R1 can attenuate SAP-induced ALI. The mechanism of action may be due to a decreased expression of miR-128-2-5p, increased activity of the Tollip signaling pathway, decreased activity of HMGB1/TLR4 and ERK1 signaling pathways, and decreased inflammatory response to SAP-induced ALI. Tollip was the regulatory target of miR-128-2-5p.     

Host Platelets and,in Part,Neutrophils Mediate Lung Accumulation of Transfused UVB-Irradiated Human Platelets in a Mouse Model of Acute Lung Injury

We previously reported that ultraviolet light B (UVB)-treated human platelets (hPLTs) can cause acute lung injury (ALI) in a two-event SCID mouse model in which the predisposing event was Lipopolysaccharide (LPS) injection and the second event was infusion of UVB-treated hPLTs. To delineate contributions of host mouse platelets (mPLTs) and neutrophils in the pathogenesis of ALI in this mouse model, we depleted mPLTs or neutrophils and measured hPLT accumulation in the lung. We also assessed lung injury by protein content in bronchoalveolar lavage fluid (BALF). LPS injection followed by infusion of UVB-treated hPLTs resulted in sequestration of both mPLTs and hPLTs in the lungs of SCID mice, although the numbers of neutrophils in the lung were not significantly different from the control group. Depletion of mouse neutrophils caused only a mild reduction in UVB-hPLTs accumulation in the lungs and a mild reduction in protein content in BALF. In comparison, depletion of mPLTs almost completely abolished hPLTs accumulation in the lung and significantly reduced protein content in BALF. UVB-treated hPLTs bound to host mPLTs, but did not bind to neutrophils in the lung. Aspirin treatment of hPLTs in vitro abolished hPLT accumulation in the lung and protected mice from lung injury. Our data indicate that host mPLTs accumulated in the lungs in response to an inflammatory challenge and subsequently mediated the attachment of transfused UVB-hPLTs. Neutrophils also recruited a small percentage of platelets to the lung. These findings may help develop therapeutic strategies for ALI which could potentially result from transfusion of UV illuminated platelets.     

Metabolic profiling in human lung injuries by high-resolution nuclear magnetic resonance spectroscopy of bronchoalveolar lavage fluid (BALF)

We present a method for identifying biomarkers in human lung injury. The method is based on high-resolution nuclear magnetic resonance (NMR) spectroscopy applied to bronchoalveolar lavage fluid (BALF) collected from lungs of critically ill patients. This biological fluid can be obtained by bronchoscopic and non-bronchoscopic methods. The type of lung injury in acute respiratory failure presenting as acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), continues to challenge critical care physicians. We characterize different metabolites in BAL fluid by non-bronchoscopic method (mBALF) for better diagnosis and understanding of ALI/ARDS by NMR spectroscopy. NMR spectra of mBALF collected from 30 patients (9 controls, 10 ARDS and 11 ALI) were analyzed for the identification of biomarkers. Statistical methods such as principal components analysis and partial least square discriminant analysis were carried out on ¹H NMR spectrum of mBALF to identify biomarker responsible for separation among different lung injuries classes (ALI and ARDS) and normal lungs. The corresponding correlation of biomarkers with metabolic cycle has given insight into metabolism of lung injuries in critically ill patients. Our study shows statistically significant differentiation of various metabolites concentration in mBALF collected from lungs of ALI, ARDS and healthy control patients, making NMR spectroscopy as a possible new method of characterizing human lung injury.     

Intratracheal transplantation of human umbilical cord blood-derived mesenchymal stem cells attenuates Escherichia coli-induced acute lung injury in mice

Background

Human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) attenuate hyperoxic neonatal lung injury primarily through anti-inflammatory effects. We hypothesized that intratracheal transplantation of human UCB-derived MSCs could attenuate Escherichia coli (E. coli)-induced acute lung injury (ALI) in mice by suppressing the inflammatory response.

Methods

Eight-week-old male ICR mice were randomized to control or ALI groups. ALI was induced by intratracheal E. coli instillation. Three-hours after E. coli instillation, MSCs, fibroblasts or phosphate-buffered saline were intratracheally administered randomly and survival was analyzed for 7 days post-injury. Lung histology including injury scores, myeloperoxidase (MPO) activity, and protein levels of interleukin (IL)-1α, IL-1β, IL-6, tumor necrosis factor (TNF)-α, and macrophage inflammatory protein (MIP)-2 as well as the wet-dry lung ratio and bacterial counts from blood and bronchoalveolar lavage (BAL) were evaluated at 1, 3, and 7 days post-injury. Levels of inflammatory cytokines in the lung were also profiled using protein macroarrays at day 3 post-injury which showed peak inflammation.

Results

MSC transplantation increased survival and attenuated lung injuries in ALI mice, as evidenced by decreased injury scores on day 3 post-injury and reduced lung inflammation including increased MPO activity and protein levels of IL-1α, IL-1β, IL-6, TNF-α, and MIP-2 on day 3 and 7 post-injury. Inflammatory cytokine profiles in the lungs at day 3 post-injury were attenuated by MSC transplantation. MSCs also reduced the elevated lung water content at day 3 post-injury and bacterial counts in blood and BAL on day 7 post-injury.

Conclusions

Intratracheal transplantation of UCB-derived MSCs attenuates E. coli-induced ALI primarily by down-modulating the inflammatory process and enhancing bacterial clearance.     

Ursodeoxycholic acid protects against lung injury induced by fat embolism syndrome

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a life‐threatening disease with a high mortality rate, which was a common complication of fat embolism syndrome (FES). Ursodeoxycholic acid (UDCA) has been reported to exert potent anti‐inflammatory effects under various conditions. In vivo, perinephric fat was injected via tail vein to establish a rat FES model, the anti‐inflammatory effects of UDCA on FES‐induced lung injury were investigated through histological examination, ELISA, qRT‐PCR, Western blot and immunofluorescence. In vitro, human lung microvascular endothelial cells (HPMECs) were employed to understand the protective effects of UDCA. The extent of ALI/ARDS was evaluated and validated by reduced PaO₂/FiO₂ ratios, increased lung wet/dry (W/D) ratios and impaired alveolar‐capillary barrier, up‐regulation of ALI‐related proteins in lung tissues (including myeloperoxidase [MPO], vascular cell adhesion molecule 1 [VCAM‐1], intercellular cell adhesion molecule‐1 [ICAM‐1]), elevated protein concentration and increased proinflammatory cytokines levels (TNF‐α and IL‐1β) in bronchoalveolar lavage fluid (BALF). Pre‐treatment with UDCA remarkably alleviated these pathologic and biochemical changes of FES‐induced ALI/ARDS; our data demonstrated that pre‐treatment with UDCA attenuated the pathologic and biochemical changes of FES‐induced ARDS, which provided a possible preventive therapy for lung injury caused by FES.     

The effect of HMGB1 A box on lung injury in mice with acute pancreatitis

The objective of this study is to observe the effect of high-mobility group protein B1 A Box (HMGB1 A) box on lung injury in mice with acute pancreatitis and its effect on the level of high-mobility group protein B1 (HMGB1) in lung, to explore the mechanism. A total of 60 male Institute of Cancer Research mice were randomly divided into control group (n = 30) and treatment group (n = 30). Severe acute pancreatitis mice model was induced by 20% L-Arg intraperitoneal injection. The recombination HMGB1 A box was used in treatment after modeling. All the mice were killed under anesthesia at 24 and 48 h after the modeling injection. The level of HMGB1 and activity of myeloperoxidase (MPO) in lung were measured. The pathological changes of lung were observed. The level of HMGB1 in lung of A box treatment group decreased more significantly 24 h and 48 h after modeling compared with control group. The activity of MPO in lung of A box treatment group decreased more significantly 24 h after modeling compared with control group. The lung tissue pathologic score of A box treatment group decreased more significantly 48 h after modeling compared with control group. HMGB1 expression levels in the lungs were positively related to histological score of injured lung in acute pancreatitis. It indicates that HMGB1 A box is remarkably protective to lung injury induced by acute pancreatitis.     

Production of leukotrienes in phorbol ester-induced acute lung injury

Leukotrienes, when administered into the pulmonary circulation of intact animals or isolated perfused lungs, have been associated with the formation of pulmonary edema. In addition, leukotrienes were identified in edema fluid and in bronchoalveolar lavage fluid (BALF) both from patients with the adult respiratory distress syndrome (ARDS) and from dogs with ethchlorvynol-induced acute lung injury (ALI). To determine whether the identification of leukotrienes in BALF was a finding common to ALI, etiology notwithstanding, we produced acute lung injury in dogs with phorbol myristate acetate (PMA). PMA produces a model of ALI thought to differ mechanistically from ethchlorvynol-induced ALI. Leukotriene C4 (LTC4), D4 (LTD4) and B4 (LTB4) were measured in BALF before and after PMA administration in intact pentobarbital-anesthetized dogs. The intravenous administration of 20 or 30 micrograms/kg of PMA produced increases in pulmonary vascular resistance (PVR) and extravascular lung water (EVLW), whereas, 10 or 15 micrograms/kg caused only a modest increase in PVR with no increase in EVLW. LTD4 and LTB4 were increased in BALF solely in those animals that developed increases in EVLW. These results, when viewed together with those reported in humans with ARDS and in dogs with ethchlorvynol-induced ALI, support the hypothesis that leukotriene detection in BALF is a feature common to ALI, etiology notwithstanding.     

High-Mobility Group Box-1 Induces Proinflammatory Cytokines Production of Kupffer Cells through TLRs-Dependent Signaling Pathway after Burn Injury

Kupffer cells (KCs) were a significant source of cytokine release during the early stage of severe burns. High mobility group box protein 1 (HMGB1) was recently identified as a new type of proinflammatory cytokine. The ability of HMGB1 to generate inflammatory responses after burn trauma has not been well characterized. KCs were isolated from sham animals and rats with a 30% full-thickness burn, and then were stimulated with increasing concentrations of HMGB1. The levels of Tumor necrosis factor (TNF)-α and interleukin (IL)-1β in culture supernatant were measured by enzyme-linked immunosorbent assay. Northern blot analysis was performed to detect the expressions of TNF-α and IL-1β mRNAs. The activities of p38 MAPK and JNK (by Western blot analysis) as well as NF-κB (by EMSA) in KCs were also examined. As a result, HMGB1 in vitro upregulated expressions of TNF-α and IL-1β of KCs in a dose-dependent manner, and HMGB1 promoted KCs from burn rats to produce significantly more TNF-α and IL-1β proteins than those from sham animals. After harvested from burn rats, KCs were pre-incubated with anti-TLR2 or anti-TLR4 antibody prior to HMGB1 administration. HMGB1 exposure not only significantly increased expressions of TNF-α and IL-1β mRNAs in KCs from burn rats, but also enhanced activities of p38 MAPK, JNK and NF-κB. However, these upregulation events were all reduced by pre-incubation with anti-TLR2 or anti-TLR4 antibody. These results indicate that HMGB1 induces proinflammatory cytokines production of KCs after sever burn injury, and this process might be largely dependent on TLRs-dependent MAPKs/NF-κB signal pathway.     

急性肺损伤大鼠肺组织高迁移率族蛋白1的表达及其意义

目的动态观察高迁移率族蛋白1（HGMB1）在失血性休克复合内毒素注射致急性肺损伤（ALl）大鼠肺组织的表达情况,初步探讨HMGB1在ALI发病机制中的作用。方法采取失血性休克复合内毒素注射手段建立ALl大鼠动物模型,采用RT-PCR方法,检测肺组织HMGB1mRNA的表达情况。结果正常大鼠肺组织有少量HMGBlmRNA表达,遭受失血性休克复合内毒素注射打击后,HMGB1mRNA表达迅速升高,至ALI24h达最高峰,随后有所下降,ALl各组大鼠表达水平与正常对照组比较差异均有统计学意义（P〈0．01）。结论正常大鼠肺组织有一定水平HMGBlmRNA的表达,遭受失血性休克及内毒素注射打击后,HMGBlmRNA表达异常增高,可引起过度炎症反应,从而促进ALI的发生与发展。     

Baclofen,a GABABR Agonist,Ameliorates Immune-Complex Mediated Acute Lung Injury by Modulating Pro-Inflammatory Mediators

Immune-complexes play an important role in the inflammatory diseases of the lung. Neutrophil activation mediates immune-complex (IC) deposition-induced acute lung injury (ALI). Components of gamma amino butyric acid (GABA) signaling, including GABA B receptor 2 (GABA_BR2), GAD65/67 and the GABA transporter, are present in the lungs and in the neutrophils. However, the role of pulmonary GABA_BR activation in the context of neutrophil-mediated ALI has not been determined. Thus, the objective of the current study was to determine whether administration of a GABA_BR agonist, baclofen would ameliorate or exacerbate ALI. We hypothesized that baclofen would regulate IC-induced ALI by preserving pulmonary GABA_BR expression. Rats were subjected to sham injury or IC-induced ALI and two hours later rats were treated intratracheally with saline or 1 mg/kg baclofen for 2 additional hours and sacrificed. ALI was assessed by vascular leakage, histology, TUNEL, and lung caspase-3 cleavage. ALI increased total protein, tumor necrosis factor α (TNF-α and interleukin-1 receptor associated protein (IL-1R AcP), in the bronchoalveolar lavage fluid (BALF). Moreover, ALI decreased lung GABA_BR2 expression, increased phospho-p38 MAPK, promoted IκB degradation and increased neutrophil influx in the lung. Administration of baclofen, after initiation of ALI, restored GABA_BR expression, which was inhibited in the presence of a GABA_BR antagonist, CGP52432. Baclofen administration activated pulmonary phospho-ERK and inhibited p38 MAPK phosphorylation and IκB degradation. Additionally, baclofen significantly inhibited pro-inflammatory TNF-α and IL-1βAcP release and promoted BAL neutrophil apoptosis. Protective effects of baclofen treatment on ALI were possibly mediated by inhibition of TNF-α- and IL-1β-mediated inflammatory signaling. Interestingly, GABA_BR2 expression was regulated in the type II pneumocytes in lung tissue sections from lung injured patients, further suggesting a physiological role for GABA_BR2 in the repair process of lung damage. GABA_BR2 agonists may play a potential therapeutic role in ALI.     

HMGB1 在a2A- 肾上腺素受体介导脓毒血症大鼠急性肺损伤的作用

目的:探讨HMGB1在a2A-肾上腺素受体介导脓毒血症大鼠急性肺损伤(ALI)的作用。方法:64大鼠建立盲肠结扎穿孔法(CLP)脓毒症模型,随机均分为以下两组:CLP组及CLP+马来酸钠组。各组分别于模型建立后2(T1)、6(T2)、12(T3)、24 h(T4)时检测大鼠血清TNF-、高迁移率族蛋白1(HMGB1)及IL-10含量。CLP24 h后检测肺组织干湿重比(W/D)和髓过氧化物酶活性(MPO)及HMGB1表达;并采用HE法进行肺组织学评分。结果:CLP+马来酸钠组T2时的TNF-水平明显低于CLP组(P<0.05);而HMGB1在T2、T3及T4均明显低于CLP组(P<0.05);IL-10在各个时间点比较结果差异无统计学意义(P>0.05)。CLP+马来酸钠组肺组织W/D、MPO活性、肺组织损伤评分均明显低于CLP组(P<0.05)。CLP+马来酸钠组肺组织HMGB1表达明显低于CLP组(P<0.05)。结论:HMGB1参与了ALI的病理过程,a2A-肾上腺素受体阻断可以通过抑制HMGB1从而改善ALI时的肺功能。     

Selective decontamination of the digestive tract attenuated the myocardial inflammation and dysfunction that occur with burn injury

This study examined the effects of oral antibiotics to selectively decontaminate the digestive tract (SDD) on postburn myocardial signaling, inflammation, and function. We hypothesized that antibiotic therapy to eliminate pathogens from the gastrointestinal (GI) tract would reduce myocardial inflammatory responses and improve postburn myocardial performance. Sprague-Dawley rats received polymyxin E (15 mg), tobramycin (6 mg), and 5-flucytosin (100 mg) by oral gavage twice daily for 3 days preburn and 24 h postburn. Experimental groups included 1) sham burn given vehicle (3 ml water), 2) sham plus SDD, 3) burn over 40% total body surface area (TBSA) plus SDD, and 4) burn over 40% TBSA given vehicle. All burns received lactated Ringer solution (4 mg.kg(-1).%burn(-1)); myocardial signaling (PKCepsilon/p38 MAPK/NF-kappaB) was studied 2, 4, and 24 h postburn; and cytokine secretion (systemic and myocyte secreted cytokines, ELISA) and cardiac function were examined 24 h postburn. Vehicle-treated burn injury increased myocardial PKCepsilon/p38 MAPK expression, promoted NF-kappaB nuclear translocation, promoted TNF-alpha, IL-1beta, IL-6, and IL-10 secretion, and impaired myocardial function. SDD attenuated burn-related proinflammatory myocardial signaling, cytokine secretion, and myocardial contractile defects. Our data suggest that burn-related loss of GI barrier function and translocation of microbial products serve as upstream mediators of postburn myocardial inflammatory signaling and dysfunction.     

Bupleurum chinense DC polysaccharides attenuates lipopolysaccharide-induced acute lung injury in mice

Bupleurum chinense DC had hepato-protective, anti-inflammatory, antipyretic, analgesic, and immunomodulatory effect in traditional Chinese medicine. This study was to determine whether the crude polysaccharides isolated from the roots of Bupleurum chinense DC (BCPs) attenuated lipopolysaccharide (LPS)-induced acute lung injury in mice. Mice were challenged with LPS intratracheally 2 h before BCPs (20, 40 and 80 mg/kg) administration. The bronchoalveolar lavage fluid (BALF) was collected 24 h after LPS challenge. Treatment with BCPs reduced lung wet-to-dry weight ratio. The elevated number of total cells and protein concentration in BALF was reduced. The increased level of myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α) in BALF, and serum nitric oxide (NO) were also inhibited. BCPs significantly attenuated lung injury with improved lung morphology and reduced complement deposition. These results suggested that the effect of BCPs against ALI might be related with its inhibitory effect on excessive activation of complement and on the production of proinflammatory mediators.     

Down-regulation of miR-let-7e attenuates LPS-induced acute lung injury in mice via inhibiting pulmonary inflammation by targeting SCOS1/NF-κB pathway

Excessive pulmonary inflammatory response is critical in the development of acute lung injury (ALI). Previously, microRNAs (miRNAs) have been recognized as an important regulator of inflammation in various diseases. However, the effects and mechanisms of miRNAs on inflammatory response in ALI remain unclear. Herein, we tried to screen miRNAs in the processes of ALI and elucidate the potential mechanism. Using a microarray assay, microRNA let-7e (let-7e) was chose as our target for its reported suppressive roles in several inflammatory diseases. Down-regulation of let-7e by antagomiR-let-7e injection attenuated LPS-induced acute lung injury. We also found that antagomiR-let-7e could obviously improve the survival rate in ALI mice. Moreover, antagomiR-let-7e treatment reduced the production of proinflammatory cytokines (i.e., TNF-α, IL-1β and IL-6) in bronchoalveolar lavage fluid (BALF) of LPS-induced ALI mice. Luciferase reporter assays confirmed that suppressor of cytokine signaling 1 (SOCS1), a powerful attenuator of nuclear factor kappa B (NF-κB) signaling pathway, was directly targeted and suppressed by let-7e in RAW264.7 cells. In addition, it was further observed that SOCS1 was down-regulated, and inversely correlated with let-7e expression levels in lung tissues of ALI mice. Finally, down-regulation of let-7e suppressed the activation of NF-κB pathway, as evidenced by the reduction of p-IκBα, and nuclear p-p65 expressions in ALI mice. Collectively, our findings indicate that let-7e antagomir protects mice against LPS-induced lung injury via repressing the pulmonary inflammation though regulation of SOCS1/NF-κB pathway, and let-7e may act as a potential therapeutic target for ALI.     

Regulation of hepatocyte growth factor secretion by fibroblasts in patients with acute lung injury

The mechanisms of pulmonary repair in acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are poorly known. Hepatocyte growth factor (HGF) and keratinocyte growth factor (KGF) are key factors involved in alveolar epithelial repair, present in the bronchoalveolar lavage fluid (BALF) from patients with ALI/ARDS. The role of BALF mediators in their production remains to be determined. We evaluated the overall effect of BALF from 52 patients (27 ventilated patients with ALI/ARDS, 10 ventilated patients without ALI, and 15 nonventilated control patients) on HGF and KGF synthesis by lung fibroblasts. Fibroblasts were cultured in the presence of BALF. HGF and KGF protein secretion was measured using ELISA, and mRNA expression was evaluated using quantitative real-time RT-PCR. Only BALF from ALI/ARDS patients upregulated both HGF and KGF mRNA expression and protein synthesis (+271 and +146% for HGF and KGF, respectively). BALF-induced HGF synthesis from ALI/ARDS patients was higher than that from ventilated patients without ALI (P < 0.05). HGF secretion was correlated with BALF IL-1beta levels (rho = 0.62, P < 0.001) and BALF IL-1beta/IL-1 receptor antagonist ratio (rho = 0.54, P < 0.007) in the ALI/ARDS group. An anti-IL-1beta antibody partially (>50%) inhibited the BALF-induced HGF and PGE(2) secretion, whereas NS-398, a specific cyclooxygenase-2 (COX-2) inhibitor, completely inhibited it. Anti-IL-1beta antibodies as well as NS-398 reversed the COX-2 upregulation induced by BALF. Therefore, IL-1beta is a main BALF mediator involved in HGF secretion, which is mediated through a PGE(2)/COX-2-dependent mechanism. BALF mediators may participate in vivo in the production of HGF and KGF by lung fibroblasts during ALI/ARDS.     

Administration of microparticles from blood of the lipopolysaccharide-treated rats serves to induce pathologic changes of acute respiratory distress syndrome

This study was conducted to investigate the effect of intratracheal and intravenous administration of microparticles (MPs) on developing acute respiratory distress syndrome (ARDS). The blood MPs from lipopolysaccharide-treated rats were collected and examined by transmission electron microscopy (TEM). Cellular source of the MPs was identified by fluorescent-labeled antibodies after the circulating MPs were delivered to naïve rats. Levels of myeloperoxidase (MPO), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-10 productions in bronchoalveolar lavage fluid (BALF) and plasma were determined 24 h after the rats received intratracheal and intravenous administration of the MPs. Histopathologic examination of lungs was performed by light microscope. A TEM image of MPs showed spherical particles at a variable diameter from 0.1 to 0.5 µm. Endothelial- and leukocyte-derived vesicles were abundant in the investigated samples. Treatment with MPs may lead to significant increases in MPO, TNF-α, IL-1β, and IL-10 productions in BALF and plasma of the rats (all P < 0.001). Morphological observation indicated that alveolar structures were destroyed with a large amount of neutrophil infiltration in the lungs of the MP-treated rats. Perivascular and/or intra-alveolar hemorrhage were serious and hyaline membrane formed in the alveoli. Intratracheal and intravenous approaches to delivery of the circulating MPs to naïve recipient rats may induce ARDS. This presents an inducer of the onset of ARDS and provides potential therapeutic targets for attenuating lung injury.     

Lung-protective effect of Punicalagin on LPS-induced acute lung injury in mice

Background: Punicalagin (Pun) is one of the main bioactive compounds in pomegranate peel, it possesses many properties, including antioxidant, anti-inflammation and immunosuppressive activities. The study was aimed to investigate the protective effect and mechanisms of Pun on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice.Methods and Results: Forty-eight BALB/c male mice were used to establish ALI by intratracheal-instilled 2.4 mg/kg LPS, the mice were randomly divided into model and Pun (10, 20, 40 mg/kg) groups. The other 12 mice were intratracheal-instilled same volume of water as control. After 2 h of receiving LPS, mice were administered drug through intraperitoneal injection. Lung index, histopathological changes, white blood cells and biomarkers in bronchoalveolar lavage fluid (BALF) were analyzed. The protein expression of total and phosphor p65, IκBα, ERK1/2, JNK and p38 in lung tissue was detected. The result showed that Pun could reduce the lung index and wet/dry weight (W/D) ratio, improve lung histopathological injury. In addition, Pun decreased the inflammation cells and regulated the biomarkers in BALF. Furthermore, Pun dose-dependently reduced the phosphor protein levels of p65, IκBα, ERK1/2, JNK and p38 in lung tissue, which exhibited that the effect of Pun related to mitogen-activated protein kinases (MAPKs) pathway. More importantly, there was no toxicity was observed in the acute toxicity study of Pun.Conclusion: Pun improves LPS-induced ALI mainly through its anti-inflammatory properties, which is associated with nuclear factor-κB (NF-κB) and MAPKs signaling pathways. The study implied that Pun maybe a potent agent against ALI in future clinic.     

Burn injury decreases myocardial Na-K-ATPase activity: role of PKC inhibition

Cardiomyocyte sodium accumulation after burn injury precedes the development of myocardial contractile dysfunction. The present study examined the effects of burn injury on Na-K-ATPase activity in adult rat hearts after major burn injury and explored the hypothesis that burn-related changes in myocardial Na-K-ATPase activity are PKC dependent. A third-degree burn injury (or sham burn) was given over 40% total body surface area, and rats received lactated Ringer solution (4 ml.kg(-1).% burn(-1)). Subgroups of rats were killed 2, 4, or 24 h after burn (n = 6 rats/time period), hearts were homogenized, and Na-K-ATPase activity was determined from ouabain-sensitive phosphate generation from ATP by cardiac sarcolemmal vesicles. Additional groups of rats were studied at several times after burn to determine the time course of myocyte sodium loading and the time course of myocardial dysfunction. Additional groups of sham burn-injured and burn-injured rats were given calphostin, an inhibitor of PKC, and Na-K-ATPase activity, cell Na(+), and myocardial function were measured. Burn injury caused a progressive rise in cardiomyocyte Na(+), and myocardial Na-K-ATPase activity progressively decreased after burn, while PKC activity progressively rose. Administration of calphostin to inhibit PKC activity prevented both the burn-related decrease in myocardial Na-K-ATPase and the rise in intracellular Na(+) and improved postburn myocardial contractile performance. We conclude that burn-related inhibition of Na-K-ATPase likely contributes to the cardiomyocyte accumulation of intracellular Na(+). Since intracellular Na(+) is one determinant of electrical-mechanical recovery after insults such as burn injury, burn-related inhibition of Na-K-ATPase may be critical in postburn recovery of myocardial contractile function.     

Lung inflammation and endothelial cell damage are decreased after treatment with phototherapy (PhT) in a model of acute lung injury induced by Escherichia coli lipopolysaccharide in the rat

Lipopolysaccharide (LPS) mimics the symptoms of acute lung injury (ALI), which is characterized by the accumulation in the lungs of neutrophils producing inflammatory mediators. Because of the lack of information about phototherapy (PhT) effects on ALI, we investigated whether PhT (685 nm InGaAlP) attenuates LPS-induced ALI. PhT reduced lung edema, the accumulation of TNF-α in the lung, and myeloperoxidase (MPO) activity. However, PhT was not efficient in reducing of TNF-α concentration in both serum and neutrophils of blood after LPS. In another series of experiments, in vitro assays of the effects of PhT effect on mouse pulmonary arterial endothelium cells (MPAECs) after TNF-α showed that the laser restores the MPAECs damage induced at 6 or 24 h after TNF-α. These results suggest the PhT effect on ALI is partly due to inhibition of TNF-α release from neutrophils and lung cells.     

Angiogenesis gene expression in murine endothelial cells during post-pneumonectomy lung growth

Background

Human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) attenuate hyperoxic neonatal lung injury primarily through anti-inflammatory effects. We hypothesized that intratracheal transplantation of human UCB-derived MSCs could attenuate Escherichia coli (E. coli)-induced acute lung injury (ALI) in mice by suppressing the inflammatory response.

Methods

Eight-week-old male ICR mice were randomized to control or ALI groups. ALI was induced by intratracheal E. coli instillation. Three-hours after E. coli instillation, MSCs, fibroblasts or phosphate-buffered saline were intratracheally administered randomly and survival was analyzed for 7 days post-injury. Lung histology including injury scores, myeloperoxidase (MPO) activity, and protein levels of interleukin (IL)-1α, IL-1β, IL-6, tumor necrosis factor (TNF)-α, and macrophage inflammatory protein (MIP)-2 as well as the wet-dry lung ratio and bacterial counts from blood and bronchoalveolar lavage (BAL) were evaluated at 1, 3, and 7 days post-injury. Levels of inflammatory cytokines in the lung were also profiled using protein macroarrays at day 3 post-injury which showed peak inflammation.

Results

MSC transplantation increased survival and attenuated lung injuries in ALI mice, as evidenced by decreased injury scores on day 3 post-injury and reduced lung inflammation including increased MPO activity and protein levels of IL-1α, IL-1β, IL-6, TNF-α, and MIP-2 on day 3 and 7 post-injury. Inflammatory cytokine profiles in the lungs at day 3 post-injury were attenuated by MSC transplantation. MSCs also reduced the elevated lung water content at day 3 post-injury and bacterial counts in blood and BAL on day 7 post-injury.

Conclusions

Intratracheal transplantation of UCB-derived MSCs attenuates E. coli-induced ALI primarily by down-modulating the inflammatory process and enhancing bacterial clearance.