HSP70 Is a Critical Regulator of HSP90 Inhibitor's Effectiveness in Preventing HCl-Induced Chronic Lung Injury and Pulmonary Fibrosis.

Exposure to hydrochloric acid (HCl) can provoke acute and chronic lung injury. Because of its extensive production for industrial use, frequent accidental exposures occur, making HCl one of the top five chemicals causing inhalation injuries. There are no Food and Drug Administration (FDA)-approved treatments for HCl exposure. Heat shock protein 90 (HSP90) inhibitors modulate transforming growth factor-ß (TGF-ß) signaling and the development of chemical-induced pulmonary fibrosis. However, little is known on the role of Heat Shock Protein 70 (HSP70) during injury and treatment with HSP90 inhibitors. We hypothesized that administration of geranylgeranyl-acetone (GGA), an HSP70 inducer, or gefitinib (GFT), an HSP70 suppressant, alone or in combination with the HSP90 inhibitor, TAS-116, would improve or worsen, respectively, HCl-induced chronic lung injury in vivo and endothelial barrier dysfunction in vitro. GGA, alone, improved HCl-induced human lung microvascular endothelial cells (HLMVEC) barrier dysfunction and, in combination with TAS-116, improved the protective effect of TAS-116. In mice, GGA reduced HCl toxicity and while TAS-116 alone blocked HCl-induced chronic lung injury, co-administration with GGA, resulted in further improvement. Conversely, GFT potentiated HCl-induced barrier dysfunction and impaired the antidotal effects of TAS-116. We conclude that combined treatments with HSP90 inhibitors and HSP70 inducers may represent a novel therapeutic approach to manage HCl-induced chronic lung injury and pulmonary fibrosis.

Growth hormone-releasing hormone antagonists protect against hydrochloric acid-induced endothelial injury in vitro.

Growth hormone-releasing hormone (GHRH) regulates the synthesis of growth hormone from the anterior pituitary gland, and it is involved in inflammatory responses. On the other hand, GHRH antagonists (GHRHAnt) exhibit the opposite effects, resulting in endothelial barrier enhancement. Exposure to hydrochloric acid (HCL) is associated with acute and chronic lung injury. In this study, we investigate the effects of GHRHAnt in HCL-induced endothelial barrier dysfunction, utilizing commercially available bovine pulmonary artery endothelial cells (BPAEC). Cell viability was measured by utilizing 3-(4,5-dimethylthiazol2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, fluorescein isothiocyanate (FITC)-dextran was used to assess barrier function. Our observations suggest that GHRHAnt exert protective effects against HCL-induced endothelial breakdown, since those peptides counteract HCL-triggered paracellular hyperpermeability. Based on those findings, we propose that GHRHAnt represent a new therapeutic approach towards HCL-induced endothelial injury.

Cultured versus freshly isolated adipose-derived stem cells in improvement of the histopathological outcomes in HCL-induced cystitis in a rat model.

Interstitial cystitis (IC) is an incurable chronic disease. The etiology of IC is unclear, and no effective therapies have been established. Here, using a hydrogen chloride (HCL)-induced IC in a rat model, the therapeutic potency of stromal vascular fraction (SVF) and Adipose-derived stem cells (ADSCs) was studied. Thirty-six female Sprague Dawley rats were divided into four groups: the sham, HCL, (HCL+SVF) group, and (HCL+ADSCs) group (9 for each). Cystitis was induced by transurethral instillation of HCL, while PBS was used for the sham group. A single dose of SVF or ADSCs was injected into the submucosa of the rat bladder in HCL-induced IC groups. The bladder tissues were analyzed for Toluidine Blue, Masson Trichrome, CD3, and CD34 to evaluate mast cell activation, fibrosis, inflammatory cells, and bladder regeneration, respectively. Compared to HCL-induced IC, SVF or ADSCs injection into IC bladder dramatically decreased mast cell infiltration, T-cell activation, and fibrosis. Taken together, administration of SVF cells or cultured ADSCs improves the histopathological outcomes of HCL-induced bladder injury in a time-dependent manner. Of note, SVF injection into the bladder submucosa was estimated to have the most potent therapeutic efficacy and may represent an essential component in future clinical applications.

Germ cell apoptosis is critical to maintain Caenorhabditis elegans offspring viability in stressful environments.

Maintaining reproduction in highly variable, often stressful, environments is an essential challenge for all organisms. Even transient exposure to mild environmental stress may directly damage germ cells or simply tax the physiology of an individual, making it difficult to produce quality gametes. In Caenorhabditis elegans, a large fraction of germ cells acts as nurse cells, supporting developing oocytes before eventually undergoing so-called physiological germ cell apoptosis. Although C. elegans apoptosis has been extensively studied, little is known about how germline apoptosis is influenced by ecologically relevant environmental stress. Moreover, it remains unclear to what extent germline apoptosis contributes to maintaining oocyte quality, and thus offspring viability, in such conditions. Here we show that exposure to diverse environmental stressors, likely occurring in the natural C. elegans habitat (starvation, ethanol, acid, and mild oxidative stress), increases germline apoptosis, consistent with previous reports on stress-induced apoptosis. Using loss-of-function mutant alleles of ced-3 and ced-4, we demonstrate that eliminating the core apoptotic machinery strongly reduces embryonic survival when mothers are exposed to such environmental stressors during early adult life. In contrast, mutations in ced-9 and egl-1 that primarily block apoptosis in the soma but not in the germline, did not exhibit such reduced embryonic survival under environmental stress. Therefore, C. elegans germ cell apoptosis plays an essential role in maintaining offspring fitness in adverse environments. Finally, we show that ced-3 and ced-4 mutants exhibit concomitant decreases in embryo size and changes in embryo shape when mothers are exposed to environmental stress. These observations may indicate inadequate oocyte provisioning due to the absence of germ cell apoptosis. Taken together, our results show that the central genes of the apoptosis pathway play a key role in maintaining gamete quality, and thus offspring fitness, under ecologically relevant environmental conditions.

A highly conserved host lipase deacylates oxidized phospholipids and ameliorates acute lung injury in mice.

Oxidized phospholipids have diverse biological activities, many of which can be pathological, yet how they are inactivated in vivo is not fully understood. Here, we present evidence that a highly conserved host lipase, acyloxyacyl hydrolase (AOAH), can play a significant role in reducing the pro-inflammatory activities of two prominent products of phospholipid oxidation, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine and 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine. AOAH removed the sn-2 and sn-1 acyl chains from both lipids and reduced their ability to induce macrophage inflammasome activation and cell death in vitro and acute lung injury in mice. In addition to transforming Gram-negative bacterial lipopolysaccharide from stimulus to inhibitor, its most studied activity, AOAH can inactivate these important danger-associated molecular pattern molecules and reduce tissue inflammation and injury.

Sex-Related Differences in Murine Models of Chemically Induced Pulmonary Fibrosis.

We developed two models of chemically induced chronic lung injury and pulmonary fibrosis in mice (intratracheally administered hydrochloric acid (HCl) and intratracheally administered nitrogen mustard (NM)) and investigated male-female differences. Female mice exhibited higher 30-day survival and less weight loss than male mice. Thirty days after the instillation of either HCl or NM, bronchoalveolar lavage fluid displayed a persistent, mild inflammatory response, but with higher white blood cell numbers and total protein content in males vs. females. Furthermore, females exhibited less collagen deposition, milder pulmonary fibrosis, and lower Ashcroft scores. After instillation of either HCl or NM, all animals displayed increased values of phosphorylated (activated) Heat Shock Protein 90, which plays a crucial role in the alveolar wound-healing processes; however, females presented lower activation of both transforming growth factor-ß (TGF-ß) signaling pathways: ERK and SMAD. We propose that female mice are protected from chronic complications of a single exposure to either HCl or NM through a lesser activation of TGF-ß and downstream signaling. The understanding of the molecular mechanisms that confer a protective effect in females could help develop new, gender-specific therapeutics for IPF.

Gastroprotective effects of irsogladine maleate on ethanol/hydrochloric acid induced gastric ulcers in mice.

BACKGROUND/AIMS: This study was conducted to investigate the inhibitory effect of irsogladine maleate (IM) on gastric ulcers induced by ethanol and hydrochloric acid (HCl). METHODS: Mice were pretreated with IM for 1 hours before ulcer induction. Gastric ulcers were induced by oral administration of an ethanol/HCl mixture. To clarify the action mechanism of IM, the roles of 3'5'-cyclic adenosine monophosphate (cAMP), nitric oxide (NO), adenosine triphosphate-sensitive potassium (KATP) channels, prostaglandins and transient receptor potential cation channel subfamily V member 1 (TRPV1) were investigated, and lipid peroxidation in the stomach of IM-treated and -untreated animals was also measured. RESULTS: IM significantly reduced the extent of ethanol/HCl mixture-induced gastric ulceration. It exhibited dose-related gastroprotection against the ethanol/ HCl-induced lesions, while pretreatment with glibenclamide but not N(ω)-nitro- L-arginine methyl ester, reversed this action. While pretreatment with the TRPV1 antagonist capsazepine failed to effectively block the gastroprotective effect of IM, the non-selective cyclooxygenase inhibitor indomethacin almost abolished it. IM also decreased the level of thiobarbituric acid reactive substances. CONCLUSION: We concluded that IM exhibited significant gastroprotective effects in an ethanol/HCl-induced ulcer model, which appear to be mediated, at least in part, by NO, cAMP, endogenous prostaglandins, KATP channel opening, activation of TRPV1 channels, and antioxidant properties.

Hunan insect tea polyphenols provide protection against gastric injury induced by HCl/ethanol through an antioxidant mechanism in mice.

The purposes of this study were to explore the preventive and treatment effects of Hunan insect tea polyphenols (HITPs) on gastric injury in mice induced by HCl/ethanol and to investigate their molecular mechanisms of action. Both HITPs and ranitidine inhibited the formation and further deterioration of gastric mucosal lesions, reduced the secretion of gastric juice, and raised gastric juice pH compared to the control. The HITPs-H treated group had lower serum levels of motilin, substance P, and endothelin than the control group, but they had higher serum levels of vasoactive intestinal peptide and somatostatin. Mice treated with HITPs had lower serum levels of cytokines interleukin (IL)-6, IL-12, tumor necrosis factor-α (TNF-α), and interferon-γ than the control group. The activities of superoxide dismutase (SOD), nitric oxide, and glutathione peroxidase (GSH-Px) were higher in the gastric tissues of HITP-treated mice, but the malondialdehyde content was lower. Quantitative PCR analysis indicated that the mRNA expression of occludin, epidermal growth factor (EGF), EGF receptor (EGFR), vascular EGF (VEGF), inhibitor kappaB-α, cuprozinc-superoxide dismutase, manganese-superoxide dismutase, GSH-Px, neuronal nitric oxide synthase, and endothelial NOS increased significantly in the gastric tissues of HITP-treated mice. However, the activated B cell, inducible NOS, cyclooxygenase-2, TNF-α, IL-1 beta, and IL-6 mRNA expression levels in the HITPs group were lower than those in the control group. The protective effect of a high concentration (200 mg per kg bw) of HITPs on gastric injury induced by HCl/ethanol was stronger than that of a low concentration (100 mg per kg bw) of HITPs. High-performance liquid chromatography (HPLC) revealed that the HITPs contained cryptochlorogenic acid, (-)-epicatechin gallate, and isochlorogenic acid C. Taken together, our findings indicate that the HITPs played a role in the prevention of gastric damage. The antioxidant effect of the HITPs contributed to their potential value in the prevention and treatment of gastric injury. HITPs have broad prospects as biologically active substances for food development.

Acute exposure of mice to hydrochloric acid leads to the development of chronic lung injury and pulmonary fibrosis.

Objective: Accidental exposure to hydrochloric acid (HCl) is associated with acute lung injury in humans, development of long-term chronic airway obstruction, and fibrosis. However, the mechanisms responsible for the progression to pulmonary fibrosis remain unclear. We utilized a mouse model of progressive lung injury from a single exposure to HCl to investigate the effects of HCl on the lower respiratory tract. Materials and methods: HCl (0.05-0.3 N) or saline was injected intratracheally into male C57Bl/6J mice. At 1, 4, 10 and 30 days post instillation, bronchoalveolar lavage fluid (BALF) and lung tissues were collected and examined for multiple outcomes. Results and discussion: We observed an early inflammatory response and a late mild inflammation present even at 30 d post HCl exposure. Mice treated with HCl exhibited higher total leukocyte and protein levels in the BALF compared to the vehicle group. This was characterized by increased number of neutrophils, monocytes, and lymphocytes as well as pro-inflammatory cytokines during the first 4 d of injury. The late inflammatory response exhibited a predominant presence of mononuclear cells, increased permeability to protein, and higher levels of the pro-fibrotic mediator TGFß. Pro-fibrotic protein biomarkers, phosphorylated ERK, and HSP90, were also overexpressed at 10 and 30 d following HCl exposure. In vivo lung function measurements demonstrated lung dysfunction and chronic lung injury associated with increased lung hydroxyproline content and increased expression of extracellular matrix (ECM) proteins. The acute inflammation and severity of fibrosis increased in HCl-concentration dependent manner. Conclusions: Our findings suggest that the initial inflammatory response and pro-fibrotic biomarker upregulation may be linked to the progression of pulmonary fibrosis and airway dysfunction and may represent valuable therapeutic targets.

Dexmedetomidine and Magnesium Sulfate: A Good Combination Treatment for Acute Lung Injury?

Objectives: In this study, we aimed to investigate the therapeutic effects of magnesium sulfate (MgSO4) and dexmedetomidine (dex) in a model of acute lung injury (ALI). We determined whether concomitant administration decreased the inflammatory effects of hydrochloric acid (HCl)-induced ALI in a synergistic manner. Materials and Methods: In this study, 42 Sprague-Dawley rats were randomized into six groups: Group S (saline), Group SV (saline + mechanical ventilation), Group HCl (HCl), Group Dex (Dex), Group Mag (MgSO4), and Group DM (Dex + MgSO4). All groups except Group S were mechanically ventilated prior to HCl-induced ALI. Saline or HCl was administered via tracheostomy. Prior to treatment, HCl was administered to Group HCl, Group Dex, Group Mag, and Group DM to induce ALI. Dex and MgSO4 were administered intraperitoneally. The rats were monitored for 4 h after treatment to measure oxidative stress parameters in blood, and prolidase enzyme activity. Lung tissue damage were determined via histopathology. Results: A significant increase in heart rate and rapid desaturation was observed in HCl-administered groups. Treatment administration decreased the pulse values. Increased saturation values and decreased oxidative stress indices were observed in groups that were subsequently administered​ Dex and MgSO4. Serum prolidase activity increased significantly in Group HCl. Severe pathological findings were detected following HCl-induced ALI. Group Mag showed greater improvement in the pathology of HCl-induced ALI than did Group Dex. Administration of both Dex and MgSO4 did not improve the pathological scores. Conclusions: The antioxidant and anti-inflammatory effects of Dex and MgSO4 ameliorated the detrimental effects of HCI-induced ALI. However, adverse effects on hemodynamics and lung damage were observed when the two drugs were administered together.

Respiratory effects of occupational exposure to low concentration of hydrochloric acid among exposed workers: a case study in steel industry.

Occupational exposure to hydrochloric acid in pickling of steel for remove rust or iron oxide scale from iron processing occurs at low concentration. This study aimed to investigate the respiratory symptoms and pulmonary dysfunction caused by exposure to low concentration of hydrochloric acid in acid washing unit in one of the steel industries. A case control study was carried out in the acid washing unit of the cold rolling of the steel industry in 2017. The exposed group included 45 male workers, and another 41 unexposed employees from official employees were enrolled as control group. A questionnaire was used to collect personal and occupational data and pulmonary function tests, including forced vital capacity (FVC), forced expiratory volume in the first second and peak expiratory flow rate followed guidelines given by the American Thoracic Society and measured with a portable calibrated vitalograph spirometer. For determination of acid concentration, 21 breathing zone air samples were collected in accordance with Method 7903 NIOSH. The findings showed that nose sensitivity, throat irritation and shortness of breath were the highest prevalence symptoms among exposed persons (30.4% to 32.6%). Also, the results showed that FVC and forced expiratory volume in the first second had highest and direct or positive correlation with height (0.965 and 0.927, respectively). Age and weight put in the next priorities (P < 0.01). On the other hand, based on the results of multivariate linear regression, exposing to the acid and job history are two main predictor factors for FVC. So that, the exposing to acid, by itself can reduce FVC as 4.386 units. This value is equal to 1.117 for the job history. Exposure to low concentrations of hydrochloric acid alone could increase the risk of respiratory tract damage and pulmonary function disorders. But the extent to which it can cause respiratory complications for occupational exposure is still unknown and requires further study. This study was approved by Ethical Committee of Qom University of Medical Sciences (approval No. IR.MUQ.REC.1397.118) on November 6, 2018.

Downregulation of microRNA-128-3p protects human esophageal squamous Het-1A cells from hydrochloric acid-induced cell injury by targeting E2F3.

This study aimed to investigate the role of microRNA-128-3p in regulating hydrochloric acid (HCl)-induced cell injury in human esophageal squamous Het-1A cells. Het-1A cells were treated with HCl (pH 4.0) to induce esophageal injury like this caused by reflux. Whether HCl induced cell injury was then assessed by detecting cell proliferation and apoptosis. The expression of miR-128-3p in HCl-treated Het-1A cells was investigated, followed by investigating the effects of miR-128-3p overexpression and suppression on HCl-induced Het-1A cell injury. In addition, the target of miR-128-3p was identified. Besides, the association between miR-128-3p and ERK and PI3K/AKT pathways was further explored. HCl inhibited the proliferation and increased apoptosis of Het-1A cells. miR-128-3p was upregulated in Het-1A cells after HCl treatment. Inhibition of miR-128-3p alleviated HCl-induced Het-1A cell injury, whereas miR-128-3p overexpression further aggravated this injury. Moreover, E2F3 was confirmed as a target of miR-128-3p, which could be negatively regulated by miR-128-3p. Besides, miR-128-3p inhibition remarkably alleviated the inhibitory effects of HCl on the activation of ERK and PI3K/AKT pathways, which were further reversed after inhibition of miR-128-3p and E2F3 at the same time. Alltogether, our findings indicate that downregulation of microRNA-128-3p may protect human esophageal squamous cells Het-1A from HCl-induced cell injury via targeting E2F3 and inhibiting the activation of ERK and PI3K/AKT pathways. These findings provide the experimental basis for targeted treatment of reflux esophagitis.

Alisma canaliculatum ethanol extract suppresses inflammatory responses in LPS-stimulated macrophages, HCl/EtOH-induced gastritis, and DSS-triggered colitis by targeting Src/Syk and TAK1 activities.

ETHNOPHARMACOLOGICAL RELEVANCE: Alisma canaliculatum A.Braun & C.D.Bouché, distributed in Korea, Japan, China, and Taiwan, is a traditional medicine. In particular, the stem and root of Alisma canaliculatum A.Braun & C.D.Bouché are prescribed to relieve various inflammatory symptoms resulting from nephritis, cystitis, urethritis, and dropsy. AIM OF STUDY: However, the curative mechanism of Alisma canaliculatum A.Braun & C.D.Bouché with respect to inflammatory symptoms is poorly understood. In this study, the curative roles of this plant in various inflammatory conditions as well as its inhibitory mechanism were aimed to examine using an ethanol extract (Ac-EE). MATERIALS AND METHODS: Anti-inflammatory effects of Ac-EE were evaluated in lipopolysaccharide (LPS)-induced macrophages in vitro and HCl/EtOH-stimulated mouse model of gastritis and DSS-treated mouse model of colitis. To determine the potentially active anti-inflammatory components in this extracts, we employed HPLC. We also used kinase assays, reporter gene assay, immunoprecipitation analysis and target enzyme overexpressing cell analysis to analyze the molecular mechanisms and the target molecules. RESULTS: This extract dose-dependently inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) from RAW264.7 cells and peritoneal macrophages activated by lipopolysaccharide (LPS). Additionally, Ac-EE ameliorated inflammatory symptoms resulting from gastritis and colitis. Ac-EE down-regulated the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, and cyclooxygenase-2 (COX-2). Ac-EE also blocked the nuclear translocation of nuclear factor (NF)-κB and activator protein (AP)- 1 in LPS-stimulated RAW264.7 cells. By analyzing the target signaling molecules activating these transcription factors, we found that Src and Syk, as well as molecular association between TAK1 and mitogen-activated protein kinase kinase 4/7 (MKK4/7), were targeted by Ac-EE. CONCLUSIONS: Our data suggest that the Ac-EE NF-κB/AP-1-targeted anti-inflammatory potential is mediated by suppression of Src and Syk as well as the complex formation between TAK1 and its substrate proteins MKK4/7.

Instillation of hyaluronan reverses acid instillation injury to the mammalian blood gas barrier.

Acid (HCl) aspiration during anesthesia may lead to acute lung injury. There is no effective therapy. We hypothesized that HCl instilled intratracheally in C57BL/6 mice results in the formation of low-molecular weight hyaluronan (L-HA), which activates RhoA and Rho kinase (ROCK), causing airway hyperresponsiveness (AHR) and increased permeability. Furthermore, instillation of high-molecular weight hyaluronan (H-HA; Yabro) will reverse lung injury. We instilled HCl in C57BL/6 wild-type (WT), myeloperoxidase gene-deficient (MPO-/-) mice, and CD44 gene-deficient (CD44-/-) mice. WT mice were also instilled intranasally with H-HA (Yabro) at 1 and 23 h post-HCl. All measurements were performed at 1, 5, or 24 h post-HCl. Instillation of HCl in WT but not in CD44-/- resulted in increased inflammation, AHR, lung injury, and L-HA in the bronchoalveolar lavage fluid (BALF) 24 h post-HCl; L-HA levels and lung injury were significantly lower in HCl-instilled MPO-/- mice. Isolated perfused lungs of HCl instilled WT but not of CD44-/- mice had elevated values of the filtration coefficient ( Kf). Addition of L-HA on the apical surface of human primary bronchial epithelial cell monolayer decreased barrier resistance ( RT). H-HA significantly mitigated inflammation, AHR, and pulmonary vascular leakage at 24 h after HCl instillation and mitigated the increase of Kf and RT, as well as ROCK2 phosphorylation. Increased H- and L-HA levels were found in the BALF of mechanically ventilated patients but not in healthy volunteers. HCl instillation-induced lung injury is mediated by the L-HA-CD44-RhoA-ROCK2 signaling pathway, and H-HA is a potential novel therapeutic agent for acid aspiration-induced lung injury.

Barrett's metaplasia develops from cellular reprograming of esophageal squamous epithelium due to gastroesophageal reflux.

Gastroesophageal reflux disease (GERD) clinically predisposes to columnar Barrett's metaplasia (BM) in the distal esophagus. We demonstrate evidence supporting the cellular origin of BM from reprograming or transcommitment of resident normal esophageal squamous (NES) epithelial cells in response to acid and bile (A + B) exposure using an in vitro cell culture model. The hTERT-immortalized NES cell line NES-B10T was exposed 5 min/day to an A + B mixture for 30 wk. Morphological changes, mRNA, and protein expression levels for the inflammatory marker cyclooxygenase-2; the lineage-determining transcription factors TAp63 (squamous), CDX2, and SOX9 (both columnar); and the columnar lineage markers Villin, Muc-2, CK8, and mAb Das-1 (incomplete phenotype of intestinal metaplasia) were assessed every 10 wk. Markers of columnar lineage and inflammation increased progressively, while squamous lineage-determining transcriptional factors were significantly decreased both at the mRNA and/or protein level in the NES-B10T cells at/after A + B treatment for 30 wk. Distinct modifications in morphological features were only observed at/after 30 wk of A + B exposure. These changes acquired by the NES-B10T 30-wk cells were retained even after cessation of A + B exposure for at least 3 wk. This study provides evidence that chronic exposure to the physiological components of gastric refluxate leads to repression of the discernable squamous transcriptional factors and activation of latent columnar transcriptional factors. This reflects the alteration in lineage commitment of the precursor-like biphenotypic, NES-B10T cells in response to A + B exposure as the possible origin of BM from the resident NES cells.NEW & NOTEWORTHY This study provides evidence of the origins of Barrett's metaplasia from lineage transcommitment of resident esophageal cells after chronic exposure to gastroesophageal refluxate. The preterminal progenitor-like squamous cells alter their differentiation and develop biphenotypic characteristics, expressing markers of incomplete-type columnar metaplasia. Development of these biphenotypic precursors in vitro is a unique model to study pathogenesis of Barrett's metaplasia and esophageal adenocarcinoma.

Detrimental ELAVL-1/HuR-dependent GSK3ß mRNA stabilization impairs resolution in acute respiratory distress syndrome.

A hallmark of acute respiratory distress syndrome (ARDS) is accumulation of protein-rich edema in the distal airspaces and its removal is critical for patient survival. Previous studies have shown a detrimental role of Glycogen Synthase Kinase (GSK) 3ß during ARDS via inhibition of alveolar epithelial protein transport. We hypothesized that post-transcriptional regulation of GSK3ß could play a functional role in ARDS resolution. To address this hypothesis, we performed an in silico analysis to identify regulatory genes whose expression correlation to GSK3ß messenger RNA utilizing two lung cancer cell line array datasets. Among potential regulatory partners of GSK3ß, these studies identified the RNA-binding protein ELAVL-1/HuR (Embryonic Lethal, Abnormal Vision, Drosophila-Like) as a central component in a likely GSK3ß signaling network. ELAVL-1/HuR is a RNA-binding protein that selectively binds to AU-rich elements of mRNA and enhances its stability thereby increasing target gene expression. Subsequent studies with siRNA suppression of ELAVL-1/HuR demonstrated deceased GSK3ß mRNA and protein expression and improved clearance of FITC-albumin in A549 cells. Conversely, stabilization of ELAVL-1/HuR with the proteasome inhibitor MG-132 resulted in induction of GSK3ß at mRNA and protein level and attenuated FITC-albumin clearance. Utilizing ventilator-induced lung injury or intra-tracheal installation of hydrochloric acid to induce ARDS in mice, we observed increased mRNA and protein expression of ELAVL-1/HuR and GSK3ß. Together, our findings indicate a previously unknown interaction between GSK3ß and ELAV-1 during ARDS, and suggest the inhibition of the ELAV-1- GSK3ß pathways as a novel ARDS treatment approach.

Targeting of the pulmonary capillary vascular niche promotes lung alveolar repair and ameliorates fibrosis.

Although the lung can undergo self-repair after injury, fibrosis in chronically injured or diseased lungs can occur at the expense of regeneration. Here we study how a hematopoietic-vascular niche regulates alveolar repair and lung fibrosis. Using intratracheal injection of bleomycin or hydrochloric acid in mice, we show that repetitive lung injury activates pulmonary capillary endothelial cells (PCECs) and perivascular macrophages, impeding alveolar repair and promoting fibrosis. Whereas the chemokine receptor CXCR7, expressed on PCECs, acts to prevent epithelial damage and ameliorate fibrosis after a single round of treatment with bleomycin or hydrochloric acid, repeated injury leads to suppression of CXCR7 expression and recruitment of vascular endothelial growth factor receptor 1 (VEGFR1)-expressing perivascular macrophages. This recruitment stimulates Wnt/ß-catenin-dependent persistent upregulation of the Notch ligand Jagged1 (encoded by Jag1) in PCECs, which in turn stimulates exuberant Notch signaling in perivascular fibroblasts and enhances fibrosis. Administration of a CXCR7 agonist or PCEC-targeted Jag1 shRNA after lung injury promotes alveolar repair and reduces fibrosis. Thus, targeting of a maladapted hematopoietic-vascular niche, in which macrophages, PCECs and perivascular fibroblasts interact, may help to develop therapy to spur lung regeneration and alleviate fibrosis.

Non-surgical treatment of deep wounds triggered by harmful physical and chemical agents: a successful combined use of collagenase and hyaluronic acid.

Some chronic ulcers often occur with slough, not progressing through the normal stages of wound healing. Treatment is long and other therapies need to be performed in addition to surgery. Patients not eligible for surgery because of ASA class (American Society of Anesthesiologists class) appear to benefit from chemical therapy with collagenase or hydrocolloids in order to prepare the wound bed, promoting the healing process. We describe four cases of traumatic, upper limb deep wounds caused by different physical and chemical agents, emphasising the effectiveness of treatment based on topical application of collagenase and hyaluronic acid (HA) before standardised surgical procedures. We performed careful disinfection of lesions combined with application of topical cream containing hyaluronic acid, bacterial fermented sodium hyaluronate (0·2%w/w) salt, and bacterial collagenase obtained from non-pathogenic Vibrio alginolyticus (>2·0 nkat1/g). In one patient a dermo-epidermal graft was used to cover the wide loss of substance. In two patients application of a HA-based dermal substitute was done. We obtained successful results in terms of wound healing, with satisfactory aesthetic result and optimal recovery of the affected limb functionality. Topical application of collagenase and HA, alone or before standardised surgical procedures allows faster wound healing.

Reduced pulmonary blood flow in regions of injury 2 hours after acid aspiration in rats.

BACKGROUND: Aspiration-induced lung injury can decrease gas exchange and increase mortality. Acute lung injury following acid aspiration is characterized by elevated pulmonary blood flow (PBF) in damaged lung areas in the early inflammation stage. Knowledge of PBF patterns after acid aspiration is important for targeting intravenous treatments. We examined PBF in an experimental model at a later stage (2 hours after injury). METHODS: Anesthetized Wistar-Unilever rats (n = 5) underwent unilateral endobronchial instillation of hydrochloric acid. The PBF distribution was compared between injured and uninjured sides and with that of untreated control animals (n = 6). Changes in lung density after injury were measured using computed tomography (CT). Regional PBF distribution was determined quantitatively in vivo 2 hours after acid instillation by measuring the concentration of [(68)Ga]-radiolabeled microspheres using positron emission tomography. RESULTS: CT scans revealed increased lung density in areas of acid aspiration. Lung injury was accompanied by impaired gas exchange. Acid aspiration decreased the arterial pressure of oxygen from 157 mmHg [139;165] to 74 mmHg [67;86] at 20 minutes and tended toward restoration to 109 mmHg [69;114] at 110 minutes (P < 0.001). The PBF ratio of the middle region of the injured versus uninjured lungs of the aspiration group (0.86 [0.7;0.9], median [25%;75%]) was significantly lower than the PBF ratio in the left versus right lung of the control group (1.02 [1.0;1.05]; P = 0.016). CONCLUSIONS: The PBF pattern 2 hours after aspiration-induced lung injury showed a redistribution of PBF away from injured regions that was likely responsible for the partial recovery from hypoxemia over time. Treatments given intravenously 2 hours after acid-induced lung injury may not preferentially reach the injured lung regions, contrary to what occurs during the first hour of inflammation. Please see related article: http://dx.doi.org/10.1186/s12871-015-0014-z.

Acute respiratory distress syndrome: we can't miss regional lung perfusion!

In adult respiratory distress syndrome (ARDS), life-threatening hypoxemia may occur, dictating the need for differentiated ventilator strategies. Pronounced consolidation and/or atelectasis have been well documented in ARDS, but the contribution of regional perfusion to oxygenation has been poorly addressed. Evidence has accumulated that, in ARDS, regional perfusion is extremely variable and may affect oxygenation, independently from the amount of atelectatic-consolidated lung regions. Thus, the response in oxygenation to different ventilatory settings, both during controlled and assisted mechanical ventilation, should be interpreted with caution. In fact, gas exchange may be not determined solely by changes in aeration, but also redistribution of perfusion. Furthermore, regional perfusion can play an important role in worsening of lung injury due to increased transmural pressures. In addition, distribution of perfusion in lungs might affect the delivery of drugs through the pulmonary circulation, including antibiotics. In recent years, several techniques have been developed to determine pulmonary blood flow with increasing level of spatial resolution, allowing a better understanding of normal physiology and various pathophysiological conditions, but most of them are restricted to experimental or clinical research. Lung ultrasound and novel algorithms for electrical impedance tomography represent new promising techniques that could enable physicians to assess the distribution of pulmonary blood flow at the bedside. In ARDS, we cannot afford missing regional lung perfusion! Please see related article: http://dx.doi.org/10.1186/s12871-015-0013-0.