Molecules In Lung Research Articles

Polygonatum odoratum polysaccharide attenuates lipopolysaccharide-induced lung injury in mice by regulating gut microbiota.

Polygonatum odoratum is appreciated for its edible and medicinal benefits especially for lung protection. However, the contained active components have been understudied, and further research is required to fully exploit its potential application. We aimed to probe into the beneficial effects of Polygonatum odoratum polysaccharide (POP) in lipopolysaccharide-induced lung inflammatory injury mice. POP treatment could ameliorate the survival rate, pulmonary function, lung pathological lesions, and immune inflammatory response. POP treatment could repair intestinal barrier, and modulate the composition of gut microbiota, especially reducing the abundance of Klebsiella, which were closely associated with the therapeutic effects of POP. Investigation of the underlying anti-inflammatory mechanism showed that POP suppressed the generation of pro-inflammatory molecules in lung by inhibiting iNOS+ M1 macrophages. Collectively, POP is a promising multi-target microecological regulator to prevent and treat the immuno-inflammation and lung injury by modulating gut microbiota.

Up-Regulation of Claudin-6 in the Distal Lung Impacts Secondhand Smoke-Induced Inflammation.

It has long been understood that increased epithelial permeability contributes to inflammation observed in many respiratory diseases. Recently, evidence has revealed that environmental exposure to noxious material such as cigarette smoke reduces tight junction barrier integrity, thus enhancing inflammatory conditions. Claudin-6 (Cldn6) is a tetraspanin transmembrane protein found within the tight junctional complex and is implicated in maintaining lung epithelial barriers. To test the hypothesis that increased Cldn6 ameliorates inflammation at the respiratory barrier, we utilized the Tet-On inducible transgenic system to conditionally over-express Clnd6 in the distal lung. Cldn6 transgenic (TG) and control mice were continuously provided doxycycline from postnatal day (PN) 30 until euthanasia date at PN90. A subset of Cldn6 TG and control mice were also subjected to daily secondhand tobacco smoke (SHS) via a nose only inhalation system from PN30-90 and compared to room air (RA) controls. Animals were euthanized on PN90 and lungs were harvested for histological and molecular characterization. Bronchoalveolar lavage fluid (BALF) was procured for the assessment of inflammatory cells and molecules. Quantitative RT-PCR and immunoblotting revealed increased Cldn6 expression in TG vs. control animals and SHS decreased Cldn6 expression regardless of genetic up-regulation. Histological evaluations revealed no adverse pulmonary remodeling via Hematoxylin and Eosin (H&E) staining or any qualitative alterations in the abundance of type II pneumocytes or proximal non-ciliated epithelial cells via staining for cell specific propeptide of Surfactant Protein-C (proSP-C) or Club Cell Secretory Protein (CCSP), respectively. Immunoblotting and qRT-PCR confirmed the differential expression of Cldn6 and the pro-inflammatory cytokines TNF-α and IL-1β. As a general theme, inflammation induced by SHS exposure was influenced by the availability of Cldn6. These data reveal captivating information suggesting a role for Cldn6 in lungs exposed to tobacco smoke. Further research is critically necessary in order to fully explain roles for tight junctional components such as Cldn6 and other related molecules in lungs coping with exposure.

Quantitative analysis of inflammatory and adhesion molecules in lungs of neonates with chronic lung disease (bronchopulmonary dysplasia) receiving mechanical ventilation

INTRODUCTION: Chronic lung disease (CLD), clinically known as bronchopulmonary dysplasia (BPD), is a major cause of morbidity in premature newborn and were submitted to oxygen therapy. OBJECTIVE: Immunohistochemical identification of inflammatory molecules in the lung tissue of premature neonates that died with CLD. METHODS: Immunohistochemical analysis of 51 samples of premature newborn lungs – grouped in: without CLD,classic CLD andnew CLD. RESULTS: Neutrophil influx and the number of CD4+ and CD45RO+ cells were higher in theclassic CLD group (p < 0.001). CONCLUSION: Our findings suggest that the inflammatory response is mediated by neutrophils and CD45RO+ and CD4+ T lymphocytes in theclassic CLD.

Role of Interleukin-6, Its Receptor and Soluble gp130 in Chronic Lung Disease of Prematurity

Background: Interleukin-6 (IL-6) signalling involves the interplay between IL-6, soluble IL-6 receptor (sIL-6R) and soluble gp130 (sgp130). IL-6 activity is modulated by the soluble receptors to produce both pro- and anti-inflammatory effects in human diseases and animal models. The expression and functional activity of these molecules in lungs of preterm ventilated infants is unknown. Objectives: We investigated this pathway in preterm infants who were at risk of developing chronic lung disease of prematurity (CLD). Methods: Cytokines and soluble receptors were measured in bronchoalveolar lavage fluid (BALF) from ventilated preterm infants ≤32 weeks of gestation who did or did not develop CLD. B9 cells, which specifically proliferate to IL-6, were used to assess BALF IL-6 functional activity. Results: Inflammatory cells, IL-8 and monocyte chemotactic protein-1 were increased in BALF from the CLD group when compared to the No CLD group (p < 0.05). BALF IL-6 and sIL-6R were similar in both groups. In contrast, BALF sgp130 and sgp130/sIL-6R were greater in the CLD group when compared to the No CLD group (p = 0.01 and p = 0.02, respectively). However, the increased BALF sgp130 did not appear to modulate the BALF IL-6 functional activity. Conclusion: Lung inflammation was observed in the CLD group. Increased BALF sgp130 was noted in the CLD group but it did not appear to modulate the pulmonary IL-6 bioactivity. Further research is needed to investigate the potential modulatory activity of sgp130 in the preterm lung.

Protective effects of ulinastatin on pulmonary damage in rats following scald injury

Organ protection is desirable in severe burn/scald injuries, and damage mechanisms and thus effective therapies following scald injury have not been fully elucidated. Our aim was to examine the beneficial effects of ulinastatin on pulmonary damage associated with scald injury. Lewis rats were subjected to 30% total body surface area (TBSA) scald injury and were randomly divided into a burn control (S group) and an ulinastatin-treated group (U group). Lung malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined, and the lungs were examined histologically with immunohistochemistry (IHC) as well for the major histocompatibility complex (MHC) class I chain-related antigen A (MICA) and Bcl-2 at 24, 48 and 72h after the injury. The expression of spleen human leucocyte antigen-DR (HLA-DR) was detected by immunohistochemistry analysis. Selectins and adhesion molecules in lungs and serum were also detected. The lung injury degree was represented as wet/dry (W/D) values and alveolar thickness.Ulinastatin decreased MDA levels and ameliorated the down-regulation of SOD activity. MICA was up-regulated after the scald, and this up-regulation was greatly diminished by ulinastatin. Bcl-2 was up-regulated after the scald, especially in the U group. The spleen HLA-DR expression demonstrated the immunoregulatory effects of ulinastatin, which effectively protected the pulmonary tissues from scald-induced injury.Our results demonstrated that pulmonary damage was associated with autoimmunity and oxidant attack after severe scald. Ulinastatin exhibits significant protective effects on these effects.

Effects of Ligustrazine on pulmonary damage in rats following scald injury

Organ protection is a routine therapy in severe burn/scald injuries, and damage mechanisms following early scald injury was not been fully elucidated. Our aim was to verify the beneficial effects of Ligustrazine on pulmonary damage associated with scald injury.Lewis rats were subjected to 30% total body surface area (TBSA) scald injury, and were randomly divided into a burn control (S group) and an Ligustrazine-treated group (L group). Lung malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined and the lungs were examined histologically with immunohistochemistry (IHC) as well for the MHC class I chain-related antigen A (MICA) and Bcl-2 at 24, 48 and 72h after the injury. The expression of spleen HLA-DR was detected by immunohistochemistry analysis. Selectins and adhesion molecules in lungs and serum as well as pulmonary interleukins were also detected. The lung injury degree was represented as wet/dry (W/D) values and alveolar thickness.Ligustrazine decreased MDA levels and ameliorated the down-regulation of SOD activity. MICA was up-regulated after the scald, and this up-regulation was greatly diminished by Ligustrazine. Bcl-2 was up-regulated after the scald, especially in the L group. The spleen HLA-DR expression demonstrated the immunoregulatory effects of Ligustrazine, which effectively protected pulmonary tissues from scald-induced injury.Our results demonstrated that pulmonay damage associated with autoimmunity and oxidant attack occurred after severe scald. Ligustrazine exhibits significant protective effects on these effects.

Ulinastatin protects pulmonary tissues from lipopolysaccharide-induced injury as an immunomodulator

Organ protection is a routine therapy in patients with severe trauma, infection, and even multiple organ dysfunction syndrome. Appropriate inflammatory response benefits organ function with sepsis. Our aim was to verify the immunoregulatory effects of Ulinastatin (UTI) on lipopolysaccharide (LPS) administrated mice. C57BL/6J mice were subjected to an intraperitoneal injection of LPS and were randomly divided into a LPS control (L group) and an UTI-treated group (U group). Bone marrow-derived dendritic cells (DCs) were prepared from mouse femur bone marrow, and CD40, CD80, CD86, or MHC class II as DC markers were analyzed. The expression of spleen HLA-DR was detected by immunohistochemistry analysis. The alterations of Toll-like receptor 4-MyD88 signal pathway of DCs and pulmonary tissues were also determined. Selectins and adhesion molecules in lungs and serum were detected. The lung injury degree was represented as wet to dry ratios and alveolar thickness. After LPS administration, the expression of bone marrow-derived DC marker was increased, showing a mature state, while the mature process could be stepped down by UTI. The spleen HLA-DR expression and the activation degree of Toll-like receptor 4-MyD88 signal pathway also demonstrated the immunoregulatory effects of UTI, which could effectively protect the pulmonary tissues from LPS-induced injury. Our results demonstrated that UTI reduced LPS-induced pulmonary injury. The mechanism of its action might involve the immunoregulation and the mitigation of excessive inflammatory reaction.

Spaceflight modulates expression of extracellular matrix, adhesion, and profibrotic molecules in mouse lung

NASA has reported pulmonary abnormalities in astronauts on space missions, but the molecular changes in lung tissue remain unknown. The goal of the present study was to explore the effects of spaceflight on expression of extracellular matrix (ECM), cell adhesion, and pro-fibrotic molecules in lungs of mice flown on Space Shuttle Endeavour (STS-118). C57BL/6Ntac mice housed in animal enclosure modules during a 13-day mission in space (FLT) were killed within hours after return; ground controls were treated similarly for comparison (GRD). Analysis of genes associated with ECM and adhesion molecules was performed according to quantitative RT-PCR. The data revealed that FLT lung samples had statistically significant transcriptional changes, i.e., at least 1.5-fold, in 25 out of 84 examined genes (P < 0.05); 15 genes were upregulated and 10 were downregulated. The genes that were upregulated by more than twofold were Ctgf, Mmp2, Ncam1, Sparc, Spock1, and Timp3, whereas the most downregulated genes were Lama1, Mmp3, Mmp7, vcam-1, and Sele. Histology showed profibrosis-like changes occurred in FLT mice, more abundant collagen accumulation around blood vessels, and thicker walls compared with lung samples from GRD mice. Immunohistochemistry was used to compare expression of six selected proteins associated with fibrosis. Immunoreactivity of four proteins (MMP-2, CTGF, TGF-beta1, and NCAM) was enhanced by spaceflight, whereas, no difference was detected in expression of MMP-7 and MMP-9 proteins between the FLT and GRD groups. Taken together, the data demonstrate that significant changes can be readily detected shortly after return from spaceflight in the expression of factors that can adversely influence lung function.

Targeting and Imaging Signature Caveolar Molecules in Lungs

A major goal of molecular medicine is to target imaging agents or therapeutic compounds to a single organ. Targeting imaging agents to a single organ could facilitate the high-resolution, in vivo imaging of molecular events. In addition, genetic and acquired diseases primary to a single organ, such as cystic fibrosis, tuberculosis, lung cancer, pulmonary fibrosis, pulmonary hypertension, and acute respiratory distress syndrome, could be specifically targeted in the lung. By targeting and concentrating imaging agents or therapeutics to the lungs, deleterious side effects can be avoided with greater efficacy at much lower dosages. Pathologic changes can be identified earlier and followed over time. In addition, therapeutics that have been abandoned due to toxicities may find renewed utility when coupled with specific targeting agents such as antibodies. To achieve these goals, distinct molecular signatures must be found for each organ or disease-state.

Altered expression of antimicrobial molecules in cigarette smoke‐exposed emphysematous mice lungs

The natural history of COPD, a disease usually caused by cigarette smoking, is associated with frequent respiratory infections. Consistent with human COPD, bacterial clearance in the lungs has been reported to be impaired in mice exposed to cigarette smoke. In the airways, several antimicrobial molecules such as surfactant proteins (SP), beta-defensins (BD), secretory leucocyte protease inhibitor (SLPI) and lysozyme play important roles in the defence against invading pathogens. This study evaluated the expression of antimicrobial molecules in mice lungs with cigarette smoke-induced emphysematous changes. Six B6C3F1 mice were exposed to cigarette smoke (2 cigarettes/day/mouse for 6 months) or room air. Gene expression within the lungs of mice in both groups was assessed by RT-PCR. The expression of SP-A, BD2, BD3 and SLPI was significantly elevated in the lungs of cigarette smoke-exposed mice compared with air-exposed mice. BD1 expression decreased in the smoke-exposed mice and lysozyme expression was unchanged. Chronic cigarette smoke exposure did not suppress the expression of antimicrobial molecules in the lung. Altered expression of antimicrobial molecules in this mouse model does not explain the impaired host defence against respiratory microbes seen in patients with COPD.

Expression of endothelial cell-specific adhesion molecules in lungs after cardiac arrest

A method to compensate for donor shortages could be donation after cardiac death. In this study, we considered endothelial cell-specific molecules, claudin-5 and VE-cadherin, as possible biomarkers predicting lung injury against warm ischemia. We investigated how the expression of these molecules could change after cardiac arrest in a mouse lung, comparing other molecules presumably relating with ischemia. At given intervals after cardiac arrest, the lungs were harvested. Quantitative analysis of mRNA expression of claudin-5, VE-cadherin, IL-1beta, IL-10, HIF-alpha, Egr-1, VEGF, Ang-1 and Ang-2 genes in lung tissues with several periods of warm ischemia was performed. Regarding endothelial cell-specific molecules, there were significant differences in both claudin-5 and VE-cadherin mRNA expression between 0 h and 4 h after cardiac arrest. IL-1beta mRNA expression 1 h, 2 h and 4 h after cardiac arrest increased significantly, compared with that at 0 h. There were no significant differences with the other genes. We found that it took more time for claudin-5 and VE-cadherin mRNA expression to change significantly than IL-1beta mRNA expression; therefore, endothelial cell-specific molecules, claudin-5 and VE-cadherin, might be no better candidates for clinical use than IL-1beta.

Aquaporin-4 is absent at the sarcolemma and at perivascular astrocyte endfeet in α1-syntrophin knockout mice

α1-Syntrophin, a member of dystrophin-associated proteins, is expressed at the sarcolemma and at perivascular astrocytes, and participates in protein-protein interactions through its PDZ domain. Aquaporin-4 (AQP4) is the predominant water channel protein in the brain, and also expressed at the sarcolemma of fast-twitch muscle fibers. AQP4 is concentrated in orthogonal array particles (OAPs), and its expression has been reported to be decreased at the sarcolemma of dystrophin-deficient mdx mice. We examined whether α1-syntrophin targets AQP4 at the sarcolemma. Immunohistochemistry showed that AQP4 is absent at the sarcolemma in α1-syntrophin knockout mice and that its expression is also lost from the perivascular astrocyte endfeet. On the other hand, expression of AQP4 is not decreased at the sarcolemma of the knockout mice in the neonatal stage. Moreover, AQP4 is expressed in lung, stomach, and kidney of wild-type and α1-syntrophin null mice. Our results show that α1-syntrophin is a key molecule to localize AQP4 to the sarcolemma of mature fast myofibers and astrocyte endfeet, but AQP4 is targeted to the plasma membrane by different molecules in lung, stomach, and kidney.

Adenoviral vector-mediated gene therapy in the mouse lung: no role of Fas-Fas ligand interactions for elimination of transgene expression in bronchioepithelial cells.

The early successes of adenoviral vector-mediated gene therapies in the lung have been hampered by the immune response directed against viral proteins and transgene product. Intratracheal administration of adenovirus vector in immune-competent mice transduces bronchioepithelial cells of lung extremely efficiently; however, transgene expression is eliminated within 2 weeks. Extinction of transgene expression has been attributed to infiltrating cytotoxic T lymphocytes (CTLs). Fas-Fas ligand (Fas-FasL) interactions play a critical role in the effector function of the CTL killing. We have previously demonstrated that this interacting pair of molecules plays a critical role in elimination of transgene expression in mouse liver. In this study we investigated the role of Fas-FasL interactions in CTL effector functions in vivo in mouse lung. Analyses of these molecules in lung showed constitutive expression of Fas in bronchiooepithelial cells. On the other hand, FasL was inducible in the bronchioepithelial cells after adenovirus vector treatment. The in vivo role of the Fas-FasL interactions was determined by adoptive transfer of splenocytes from normal immune-competent mice to Fas-deficient mice (B6-lpr); likewise, the function of FasL on CTLs was analyzed by the ability of splenocytes from FasL-deficient mice (B6-gld) to eliminate transgene expression in Rag1-deficient mice. These studies demonstrate that despite expression of Fas and FasL in bronchioepithelial cells and CTLs, these interacting molecules do not play a critical role in elimination of transgene expression in the lung.

NMR investigations of ultraslow diffusion in incommensurate insulators and in biomedical systems (e.g. lung)

This paper discusses two new nuclear magnetic resonance (NMR) techniques for studying ultraslow atomic and molecular motions, and describes their applications to several very dissimilar situations: (1) modulation wave motions in incommensurate insulators, (2) ultraslow atomic motions between chemically inequivalent sites, and (3) restricted diffusion of water molecules in lung. Modulation wave motions and ultraslow atomic diffusion between inequivalent sites have been detected via observations of a Hahn echo decay that is shorter than the Carr–Purcell–Meiboom–Gill decay and is characterized by an exponential dependence on the cube of the echo time. They have also been detected by 2D exchange difference spectroscopy. Restricted diffusion in lung has been studied by measurements of the stimulated echo decay using very large (∼1 T/cm) static magnetic field gradients. With this technique the diffusion coefficient D has been measured at very short times, resulting in the detection of the transition from free to restricted diffusion, which in turn allows an estimate to be made of the separation of the restricting boundaries.

Evidence for a G protein-coupled diadenosine-5′,5‴- P1, P4-tetraphosphate (Ap 4A) receptor binding site in lung membranes from rat

Nucleotide receptors are of considerable importance in the treatment of lung diseases, such as cystic fibrosis. Because diadenosine polyphosphates may also be of significance as signalling molecules in lung, as they are in a variety of tissues, in the present work we investigated the binding sites for [ 3 H ]diadenosine-5′,5‴- P 1, P 4-tetraphosphate (Ap 4A) in plasma membranes from rat lung and studied their possible coupling to G proteins. We present evidence for a single high-affinity binding site for [ 3 H ]Ap 4A with similar affinity for other diadenosine polyphosphates Ap n A ( n=2 to 6). Displacement studies with different nucleotides revealed that the [ 3 H ]Ap 4A binding site was different from P2X and P2Y 2 receptor binding sites. Pretreatment of lung membranes with GTPγS or GTP in the presence of Mg 2+ increased the K i for Ap 4A from 91 nM to 5.1 μM, which is indicative of G protein coupling. The putative coupling to G proteins was further confirmed by the enhancement of [ 35 S ]GTPγS binding (to G α proteins) to lung membranes by Ap 4A (63% increase over basal) in a concentration-dependent manner. Therefore, our data for the first time provide evidence of a G protein-coupled Ap 4A binding site in lung membranes.

Mixed inhibitors of angiotensin-converting enzyme (EC 3.4.15.1) and enkephalinase (EC 3.4.24.11): rational design, properties, and potential cardiovascular applications of glycopril and alatriopril.

Angiotensin-converting enzyme (ACE) and enkephalinase, two cell surface metallopeptidases, are responsible for angiotensin II formation and atrial natriuretic factor (ANF) degradation, respectively, and thereby play a critical role in the metabolism of hormonal peptides exerting essentially opposite actions in cardiovascular regulations. To affect simultaneously both hormonal systems by a single molecular structure, we have designed glycoprilat and alatrioprilat [(S)-N-[3-(3,4-methylene-dioxyphenyl)-2-(mercaptomethyl)-1-oxoprop yl] glycine and -alanine, respectively]. In vitro the two compounds inhibit both ACE and enkephalinase activities with similar, nanomolar potencies, and in vivo, glycopril and alatriopril, the corresponding diester prodrugs, occupy the two enzyme molecules in lung at similar low dosages (0.2-0.5 mg/kg of body weight, per os). The high potency of these compounds is attributable to interaction of the methylenedioxy group with the S1 subsite of ACE and of the aromatic ring with the S1' subsite of enkephalinase. In rodents, low doses of these mixed inhibitors exert typical actions of ACE inhibitors--i.e., prevention of angiotensin I-induced hypertension--as well as of enkephalinase inhibitors--i.e., protection from 125I-ANF degradation or enhancement of diuresis and natriuresis following acute extracellular volume expansion. In view of the known counterbalanced physiological actions of the two hormonal peptides, whose metabolism is controlled by ACE and enkephalinase, mixed inhibitors of the two peptidases show promise for the treatment of various cardiovascular and salt-retention disorders.