JNK activation is responsible for mucus overproduction in smoke inhalation injury

<p>Abstract</p> <p>Background</p> <p>Increased mucus secretion is one of the important characteristics of the response to smoke inhalation injuries. We hypothesized that gel-forming mucins may contribute to the increased mucus production in a smoke inhalation injury. We investigated the role of c-Jun N-terminal kinase (JNK) in modulating smoke-induced mucus secretion.</p> <p>Methods</p> <p>We intubated mice and exposed them to smoke from burning cotton for 15 min. Their lungs were then isolated 4 and 24 h after inhalation injury. Three groups of mice were subjected to the smoke inhalation injury: (1) wild-type (WT) mice, (2) mice lacking JNK1 (JNK1-/- mice), and (3) WT mice administered a JNK inhibitor. The JNK inhibitor (SP-600125) was injected into the mice 1 h after injury.</p> <p>Results</p> <p>Smoke exposure caused an increase in the production of mucus in the airway epithelium of the mice along with an increase in MUC5AC gene and protein expression, while the expression of MUC5B was not increased compared with control. We found increased MUC5AC protein expression in the airway epithelium of the WT mice groups both 4 and 24 h after smoke inhalation injury. However, overproduction of mucus and increased MUC5AC protein expression induced by smoke inhalation was suppressed in the JNK inhibitor-treated mice and the JNK1 knockout mice. Smoke exposure did not alter the expression of MUC1 and MUC4 proteins in all 3 groups compared with control.</p> <p>Conclusion</p> <p>An increase in epithelial MUC5AC protein expression is associated with the overproduction of mucus in smoke inhalation injury, and that its expression is related on JNK1 signaling.</p

High-molecular-weight hyaluronan – a possible new treatment for sepsis-induced lung injury: a preclinical study in mechanically ventilated rats

Introduction: Mechanical ventilation with even moderate-sized tidal volumes synergistically increases lung injury in sepsis and has been associated with proinflammatory low-molecular-weight hyaluronan production. High-molecular-weight hyaluronan (HMW HA), in contrast, has been found to be anti-inflammatory. We hypothesized that HMW HA would inhibit lung injury associated with sepsis and mechanical ventilation. Methods: Sprague–Dawley rats were randomly divided into four groups: nonventilated control rats; mechanical ventilation plus lipopolysaccharide (LPS) infusion as a model of sepsis; mechanical ventilation plus LPS with HMW HA (1,600 kDa) pretreatment; and mechanical ventilation plus LPS with low-molecular-weight hyaluronan (35 kDa) pretreatment. Rats were mechanically ventilated with low (7 ml/kg) tidal volumes. LPS (1 or 3 mg/kg) or normal saline was infused 1 hour prior to mechanical ventilation. Animals received HMW HA or low-molecular-weight hyaluronan via the intraperitoneal route 18 hours prior to the study or received HMW HA (0.025%, 0.05% or 0.1%) intravenously 1 hour after injection of LPS. After 4 hours of ventilation, animals were sacrificed and the lung neutrophil and monocyte infiltration, the cytokine production, and the lung pathology score were measured. Results: LPS induced lung neutrophil infiltration, macrophage inflammatory protein-2 and TNFα mRNA and protein, which were decreased in the presence of both 1,600 kDa and 35 kDa hyaluronan pretreatment. Only 1,600 kDa hyaluronan completely blocked both monocyte and neutrophil infiltration and decreased the lung injury. When infused intravenously 1 hour after LPS, 1,600 kDa hyaluronan inhibited lung neutrophil infiltration, macrophage inflammatory protein-2 mRNA expression and lung injury in a dose-dependent manner. The beneficial effects of hyaluronan were partially dependent on the positive charge of the compound. Conclusions: HMW HA may prove to be an effective treatment strategy for sepsis-induced lung injury with mechanical ventilation

Post-Marketing Safety Surveillance of Quadrivalent Influenza Vaccine (VaxigripTetra) in Children Aged 6 to 35 Months in South Korea

Abstract Introduction The quadrivalent inactivated split-virion influenza vaccine (QIV; VaxigripTetra®) was initially licensed in South Korea in 2017 for immunization against seasonal influenza in those aged ≥ 3 years, with the indicated age subsequently lowered to include those aged ≥ 6 months in 2018. Here, to comply with South Korean licensure requirements, we undertook a post-marketing surveillance study to assess the safety of QIV in children aged 6–35 months (i.e., extension of the previous age indication to include these young children) in routine clinical practice. Methods A multicenter, observational, active safety surveillance of children aged 6–35 months who received a single dose of QIV during a routine healthcare visit was undertaken in South Korea from 15 June 2018 to 14 June 2022. Solicited adverse events (AEs) and unsolicited non-serious AEs were recorded in diary cards, with serious adverse events (SAEs) notified to study investigators. Results This safety analysis included 676 participants. No AEs led to study termination, and no SAEs were reported. The most frequent solicited injection site reaction was pain in both the ≤ 23-month (12.2% [55/450]) and ≥ 24-month (15.5% [35/226]) age groups. The most frequent solicited systemic reactions were pyrexia and somnolence in the ≤ 23-month age group (6.0% [27/450] each), and malaise (10.6% [24/226]) in the ≥ 24-month age group. Overall, 208 (30.8%) participants experienced 339 unsolicited non-serious AEs, with nasopharyngitis the most common (14.1% [95/676]), and nearly all events (98.8% [335/339]) were considered unrelated to QIV. Grade 3 solicited reactions and unsolicited non-serious AEs were reported in five (0.7%) and three (0.4%) participants, respectively, all of whom recovered by day 7 after vaccination. Conclusion This active safety surveillance study confirms that QIV is well tolerated in children aged 6–35 months in routine clinical practice in South Korea. There were no safety concerns observed in these young children

Interleukin-6 overexpression induces pulmonary hypertension

Inflammatory cytokine interleukin (IL)-6 is elevated in the serum and lungs of patients with pulmonary artery hypertension (PAH). Several animal models of PAH cite the potential role of inflammatory mediators. We investigated role of IL-6 in the pathogenesis of pulmonary vascular disease. Indices of pulmonary vascular remodeling were measured in lung-specific IL-6-overexpressing transgenic mice (Tg(+)) and compared to wild-type (Tg(-)) controls in both normoxic and chronic hypoxic conditions. The Tg(+) mice exhibited elevated right ventricular systolic pressures and right ventricular hypertrophy with corresponding pulmonary vasculopathic changes, all of which were exacerbated by chronic hypoxia. IL-6 overexpression increased muscularization of the proximal arterial tree, and hypoxia enhanced this effect. It also reproduced the muscularization and proliferative arteriopathy seen in the distal arteriolar vessels of PAH patients. The latter was characterized by the formation of occlusive neointimal angioproliferative lesions that worsened with hypoxia and were composed of endothelial cells and T-lymphocytes. IL-6-induced arteriopathic changes were accompanied by activation of proangiogenic factor, vascular endothelial growth factor, the proproliferative kinase extracellular signal-regulated kinase, proproliferative transcription factors c-MYC and MAX, and the antiapoptotic proteins survivin and Bcl-2 and downregulation of the growth inhibitor transforming growth factor-beta and proapoptotic kinases JNK and p38. These findings suggest that IL-6 promotes the development and progression of pulmonary vascular remodeling and PAH through proproliferative antiapoptotic mechanisms

Application of machine learning and laser optical-acoustic spectroscopy to study the profile of exhaled air volatile markers of acute myocardial infarction

Conventional acute myocardial infarction (AMI) diagnosis is quite accurate and has proved its effectiveness. However, despite this, discovering more operative methods of this disease detection is underway. From this point of view, the application of exhaled air analysis for a similar diagnosis is valuable. The aim of the paper is to research effective machine learning algorithms for the predictive model for AMI diagnosis constructing, using exhaled air spectral data. The target group included 30 patients with primary myocardial infarction. The control group included 42 healthy volunteers. The ‘LaserBreeze’ laser gas analyzer (Special Technologies Ltd, Russia), based on the dual-channel resonant photoacoustic detector cell and optical parametric oscillator as the laser source, had been used. The pattern recognition approach was applied in the same manner for the set of extracted concentrations of AMI volatile markers and the set of absorption coefficients in a most informative spectral range 2.900 ± 0.125 μm. The created predictive model based on the set of absorption coefficients provided 0.86 of the mean values of both the sensitivity and specificity when linear support vector machine (SVM) combined with principal component analysis was used. The created predictive model based on using six volatile AMI markers (C5H12, N2O, NO2, C2H4, CO, CO2) provided 0.82 and 0.93 of the mean values of the sensitivity and specificity, respectively, when linear SVM was used

Inducible nitric oxide mediates systemic microvascular leak following acid aspiration and mechanical ventilation

Background and aims: The systemic effects associated with mechanical ventilation of lungs injured by hydrochloric acid (HCl) aspiration are unexplored. We hypothesize that low dose acid aspiration will predispose the lung and the kidney to damage from large tidal volumes through activation of inducible nitric oxide synthase (iNOS). Materials and methods: Hydrochloric acid (HCl; pH 1.25, 1 mL/kg), or an equal amount of 0.9% sodium chloride (NaCl), were inserted into the trachea of rats immediately prior to mechanical ventilation. Rats were then ventilated with room air at 85 breaths per minute for 2 hours, either with a tidal volume (VT) of 7 mL/kg or 14 mL/kg (VT7, VT14) and zero end expiratory pressure. Kidney microvascular leak, which was assessed by measuring urine protein over 24 hours and by Evans blue dye (EBD) technique, was used as an indicator of systemic microvascular leak. Results: A significant microvascular leak occurred in both lung and kidney exposed to VT14 with HCl compared to those exposed to either VT7 with HCl or the NaCl control group. iNOS activity was significantly increased in the lung and the kidney tissue in VT14 with acid aspiration. The relatively selective iNOS inhibitor, l-N6-(1-iminoethyl)lysine (l-NIL), attenuated the EBD microvascular leak in lung and kidney and the proteinuria in the VT14 with acid aspiration group. Conclusion: iNOS may have mediated the systemic microvascular leak in the present model