EV71:TLLcho virus murine model of enterovirus A71 neurological disease does not exhibit neurogenic pulmonary oedema

Small animal models play an important role in investigating and revealing the molecular determinants and mechanisms underlying neuro-virulence of enterovirus A71 (EV-A71). In our previous study, we successfully developed two mouse cell-line replication competent EV-A71 strains (EV71:TLLm and EV71:TLLmv) which were capable of inducing neuro-invasion in BALB/c mice. The more virulent EV71:TLLmv exhibited ability to induce acute encephalomyelitis accompanied by neurogenic pulmonary oedema. EV71:TLLcho virus strain was generated from EV71:TLLm by a series of passages in CHO-K1 cells. EV71:TLLcho demonstrated a broader range of infectivity across various mammalian cell lines and exhibited complete cytopathic effects (CPE) within 48 hours post-inoculation in comparison to EV71:TLLm or EV71:TLLmv. EV71:TLLcho consistently yielded higher levels of viral replication at all time points examined. In comparison to EV71:TLLm, EV71:TLLcho consistently induced more severe disease and increased mortality in one-week old BALB/c mice. However, unlike mice challenged with EV71:TLLmv, none of the mice challenged with EV71:TLLcho progressed to severe acute encephalomyelitis and developed neurogenic pulmonary oedema.

The Role of Rosmarinic Acid in the Protection Against Inflammatory Factors in Rats Model With Monocrotaline-Induced Pulmonary Hypertension: Investigating the Signaling Pathway of NFκB, OPG, Runx2, and P-Selectin in Heart

ABSTRACT

Shortness of breath and syncope are common symptoms of right ventricular failure caused by pulmonary arterial hypertension (PAH), which is the result of blockage and increased pressure in the pulmonary arteries. There is a significant amount of evidence supporting the idea that inflammation and vascular calcification (VC) are important factors in PAH pathogenesis. Therefore, we aimed to investigate the features of the inflammatory process and gene expression involved in VC in monocrotaline (MCT)-induced PAH rats. MCT (60 mg/kg, i.p.) was used to induce PAH. Animals were given normal saline or rosmarinic acid (RA) (10, 15, and 30 mg/kg, gavage) for 21 days. An increase in right ventricular systolic pressure was evaluated as confirming PAH. To determine the level of inflammation in lung tissue, pulmonary edema and the total and differential white blood cell counts in the bronchoalveolar lavage fluid were measured. Also, the expression of NFκB, OPG, Runx2, and P-selectin genes was investigated to evaluate the level of VC in the heart. Our experiment showed that RA significantly decreased right ventricular hypertrophy, inflammatory factors, NFκB, Runx2, and P-selectin gene expression, pulmonary edema, total and differential white blood cell count, and increased OPG gene expression. Therefore, our research showed that RA protects against MCT-induced PAH by reducing inflammation and VC in rats.

Insufficiency of plasmatic arginine/homoarginine during the initial postoperative phase among patients with tumors affecting the medulla oblongata heightens the likelihood of neurogenic pulmonary oedema following surgery

BACKGROUND

This prospective clinical study aims to investigate the fluctuations of neurotransmitters in peripheral venous blood during the perioperative period and to identify independent predictors for postoperative neurogenic pulmonary oedema (NPE) in patients with medulla oblongata-involved tumours.

MATERIALS AND METHODS

Peripheral venous blood samples of the enroled patients at seven perioperative time points, as well as their medical records and radiologic data were collected. High-performance liquid chromatography-tandem mass spectrometry was utilized to detect the concentrations of 39 neurotransmitters in these samples. The study applied univariate and multivariate generalized estimating equation (GEE) logistic regression analyses to explore independent predictors of postoperative NPE, and one-way repeated-measures ANOVA to compare the concentrations of the same neurotransmitter at different perioperative time points.

RESULTS

The study included 36 patients with medulla oblongata-involved tumours from January to December 2019, and found that 13.9% of them experienced postoperative NPE. The absence of intraoperative use of sevoflurane ( P =0.008), decreased concentrations of arginine ( P =0.026) and homoarginine ( P =0.030), and prolonged postoperative tracheal extubation ( P <0.001) were identified as independent risk factors for postoperative NPE in medulla oblongata-involved tumour patients. Pairwise comparison analysis revealed that the perioperative decreases in arginine and homoarginine concentrations mainly occurred within the postoperative 8 h.

CONCLUSION

This study demonstrates that NPE is not uncommon in patients with medulla oblongata-involved tumours. The absence of intraoperative use of sevoflurane, decreased concentrations of plasmatic arginine and homoarginine, and prolonged postoperative tracheal extubation are independent predictors of postoperative NPE. These two neurotransmitters' concentrations dropped mainly within the early postoperative hours and could serve as potential early warning indicators of postoperative NPE in clinical practice.

Pinealectomy and melatonin administration in rats: their effects on pulmonary edema induced by α-naphthylthiourea

We aimed to observe the possible effects of melatonin (MLT) deprivation (pinealectomy) and exogenous MLT administration on pulmonary edema induced by alpha-naphthylthiourea (ANTU), a toxic chemical agent, in rats. Seventy animals were assigned to seven groups: control, sham pinealectomy (PINX), PINX, ANTU (10 mg/kg intraperitoneal on day 30), ANTU + MLT (10 mg/kg/day i.p. for 30 days), ANTU + PINX, and ANTU + PINX + MLT.In this study, pleural effusion (PE) formation, lung weight/body weight (LW/BW) and PE/BW ratios (fluid accumulation and weight values in the lungs) increase detected. Pre-ANTU MLT administration led to significant decreases in PE, LW/BW, and PE/BW levels. The inhibited glutathione (GSH) and superoxide dismutase (SOD) levels and high malondialdehyde (MDA) levels that ANTU increase lipid peroxidation in the study. MLT administration eliminated oxidative stress by reducing MDA and ameliorating GSH and SOD levels.Pre-ANTU MLT administration led to a significant decrease in interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) levels in the lung when compared to the ANTU group without MLT administration. Post-pinealectomy ANTU administration significantly increased IL-1β and TNF-α levels when compared to ANTU and MLT administration without pinealectomy. Diffused inflammatory cell infiltration, interstitial pulmonary edema, and histopathological congestion were observed after the administration of ANTU. Severity of the damage was elevated in the ANTU + PINX group. MLT treatment regressed pulmonary effusion and edema and improves lung structure. In brief, the findings suggested that MLT inhibited proinflammatory mediators and could serve as a therapeutic agent to prevent inflammatory disorders.

Targeting EB3-IP3R3 Interface with Cognate Peptide Protects from Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is a lung disease characterized by acute onset of noncardiogenic pulmonary edema, hypoxemia, and respiratory insufficiency. The current treatment for ARDS is mainly supportive in nature, providing a critical need for targeted pharmacological management. We addressed this medical problem by developing a pharmacological treatment for pulmonary vascular leakage, a culprit of alveolar damage and lung inflammation. Our novel therapeutic target is the microtubule accessory factor EB3 (end binding protein 3), which contributes to pulmonary vascular leakage by amplifying pathological calcium signaling in endothelial cells in response to inflammatory stimuli. EB3 interacts with IP3R3 (inositol 1,4,5-trisphosphate receptor 3) and orchestrates calcium release from endoplasmic reticulum stores. Here, we designed and tested the therapeutic benefits of a 14-aa peptide named CIPRI (cognate IP3 receptor inhibitor), which disrupted EB3-IP3R3 interaction in vitro and in lungs of mice challenged with endotoxin. Treatment with CIPRI or depletion of IP3R3 in lung microvascular endothelial monolayers mitigated calcium release from endoplasmic reticulum stores and prevented a disassembly of vascular endothelial cadherin junctions in response to the proinflammatory mediator α-thrombin. Furthermore, intravenous administration of CIPRI in mice mitigated inflammation-induced lung injury, blocked pulmonary microvascular leakage, prevented activation of NFAT (nuclear factor of activated T cells) signaling, and reduced production of proinflammatory cytokines in the lung tissue. CIPRI also improved survival of mice from endotoxemia and polymicrobial sepsis. Together, these data demonstrate that targeting EB3-IP3R3 interaction with a cognate peptide is a promising strategy to address hyperpermeability of microvessels in inflammatory lung diseases.

Further explorations into the role of mast cells in deaths associated with fatal asphyxia: an immunohistochemical study utilizing CD 117 marker

Asphyxia-related deaths have always been a challenging task in the speciality of forensic pathology. Apart from helpful macroscopical signs (e.g., strangulation mark, cyanosis, petechial haemorrhage, and lung oedema), recent literature indicates that prolonged asphyxia is sufficient to induce an increase in mast cells (MC). Inflammatory cells migrate from the bone marrow to the lungs, aiding in the diagnosis of fatal asphyxial deaths. HIF1-α, a key regulator protein, is released from lung tissue capillaries during catastrophic hypoxia circumstances, as previously demonstrated in immunohistochemistry (IHC) research. The present study analyzed lung samples from 164 medico-legal autopsy cases, including 57 asphyxia/hypoxia deaths and 107 controls (non-asphyxial deaths). Peribronchial, perivascular and perialveolar MCs were detected using CD117 antibody, and the average of MCs in each of these locations was noted in each case. The results indicated a statistically significant increase in peribronchial and perialveolar mast cells (MC) in fatal asphyxial deaths, including those caused by hanging, drowning, or postural asphyxia. Peri-bronchial MC in lung sections of asphyxial deaths were in the range of 0.2-5.4 and in non-asphyxial samples were in the range of 0.0-2.2. Peri-alveolar MCs in lung sections of asphyxial deaths were in the range of 0.0-0.6 and in non-asphyxial samples were in the range of 0.0-0.2. Our data suggest that mast cells (MC) play an important role in fatal hypoxia-related mortality and CD 117 may be a reliable marker for detection of mast cells in asphyxial deaths. It could be very beneficial to forensic pathologists tasked with differentiating fatal asphyxia fatalities from other causes of death.

Combination therapy with budesonide and acetylcysteine alleviates LPS-induced acute lung injury via the miR-381/NLRP3 molecular axis

BACKGROUND

Acute lung injury (ALI) usually has a high morbidity and mortality rate, but the current treatment is relatively scarce. Both budesonide (Bud) and N-acetylcysteine (NAC) exhibit protective effects in ALI, so we further investigated whether they have a synergistic effect on ALI when used together.

METHODS

Establishment of a rat model of ALI with Lipopolysaccharide (LPS). Bud and NAC were administered by nebulized inhalation alone or in combination. Subsequently, HE staining was performed to observe the pathological changes in lungs of rat. Evans blue staining was implemented to assess alveolar permeability, and the pulmonary edema was assessed by measuring the ratio of wet to dry weight of the lung. Moreover, a TUNEL kit was served to test apoptosis in lung tissues. Western blot and immunohistochemistry were analyzed for expression of scorch-related proteins and NLRP3 in lung tissue, respectively. ELISA was implemented to detect inflammatory factor levels in BALF. and RT-qPCR was utilized to assess the expression level of miR-381. After stable transfection of miR-381 inhibitor or OE-NLRP3 in BEAS-2B treated with LPS, Bud and NAC, miR-381 expression was assessed by RT-qPCR, scorch death-related protein expression was measured by western blot, cell proliferation/viability was assayed by CCK-8, apoptosis was measured by flow cytometry, and ELISA was implemented to assess inflammatory factor levels. Furthermore, the Dual-luciferase assay was used to verify the targeting relationship.

RESULTS

Bud and NAC treatment alone or in combination with nebulized inhalation attenuated the increased alveolar permeability, pulmonary edema, inflammatory response and scorching in LPS-induced ALI rats, and combined treatment with Bud and NAC was the most effective. In addition, combined treatment with Bud and NAC upregulated miR-381 expression and inhibited NLRP3 expression in cellular models and LPS-induced ALI rats. Transfection of the miR-381 inhibitor and OE-NLRP3 partially reversed the protective effects of Bud and NAC combination treatment on BEAS-2B cell proliferation inhibition, apoptosis, focal death and the inflammatory response.

CONCLUSION

Combined Bud and NAC nebulization therapy alleviates LPS-induced ALI by modulating the miR-381/NLRP3 molecular axis.

Single cell characteristics of patients with vaccine-related adverse reactions following inactivated COVID-19 vaccination

A good safety and immunogenicity profile was reported in Phase I and II clinical trials of inactivated SARS-CoV-2 vaccines. Here, we report two cases associated with vaccine-associated adverse events, including one patient with fever and another with anaphylactic shock resulting from inactivated SARS-CoV-2 vaccination. Cell sub-types and the importance of genetic characteristics were assessed using single-cell mRNA sequencing and machine learning. Overall, the patient with fever showed a significant increase in the numbers of cytotoxic CD8 T cells and MKI67high CD8 T cells. A potential concurrent infection with the Epstein-Barr virus enhanced interferon type I responses to vaccination against the virus. STAT1, E2F1, YBX1, and E2F7 played a key role in the transcription regulation of MKI67high CD8 T cells. In contrast, the patient with allergic shock displayed predominant increases in the numbers of S100A9high monocytes, activated CD4 T cells, and PPBPhigh megakaryocytes. The decision tree showed that LYZ and S100A8 in S100A9high monocytes contributed to the degranulation of neutrophils and activation of neutrophils involved in allergic shock. PPBP and PF4 were major contributors to platelet degranulation. These findings highlight the diversity of adverse reactions following inactivated SARS-CoV-2 vaccination and show the emerging role of cellular subtypes and central genes in vaccine-associated adverse reactions.

Discovery and pharmacological characterization of a novel benzimidazole TRPV4 antagonist with cyanocyclobutyl moiety

GSK-Bz, a TPRV4 antagonist discovered by GSK, displayed potent in vitro TRPV4 inhibition activity, and demonstrated ability to inhibit TRPV4-mediated pulmonary edema in an in vivo rat model. In this study, a series of GSK-Bz derivatives were designed and synthesized based on our previous findings. Compound 2b with cyanocyclobutyl moiety (IC₅₀ = 22.65 nM) was found to be 5.3-fold more potent than GSK-Bz (IC₅₀ = 121.6 nM) in the calcium imaging experiment. Patch-clamp experiments confirmed that compound 2b (IR = 77.1%) also gave significantly improved potency on TRPV4 currents measured at -60 mV. Furthermore, 2b effectively suppressed the permeability response to LPS in HUVEC with negligible cytotoxicity (CC₅₀ > 100 μM). The in vivo protective effects of compounds 2b on acute lung injury were finally assessed in an LPS-induced ALI mice model. Notably, 2b gave better results than HC-067047 against all of the tested indexes (lung W/D ratios, the concentrations of BALF protein and pathological scores), indicating that 2b is a novel and highly potent TRPV4 antagonist which is worth for further development. Currently, evaluation for the drug-like properties of 2b is underway.

Imatinib alleviates lung injury and prolongs survival in ventilated rats

Imatinib, a tyrosine kinase inhibitor, attenuates pulmonary edema and inflammation in lung injury. However, the physiological effects of this drug and their impact on outcomes are poorly characterized. Using serial computed tomography (CT), we tested the hypothesis that imatinib reduces injury severity and improves survival in ventilated rats. Hydrochloric acid (HCl) was instilled in the trachea (pH 1.5, 2.5 mL/kg) of anesthetized, intubated supine rats. Animals were randomized (n = 17 each group) to receive intraperitoneal imatinib or vehicle immediately prior to HCl. All rats then received mechanical ventilation. CT was performed hourly for 4 h. Images were quantitatively analyzed to assess the progression of radiological abnormalities. Injury severity was confirmed via hourly blood gases, serum biomarkers, bronchoalveolar lavage (BAL), and histopathology. Serial blood drug levels were measured in a subset of rats. Imatinib reduced mortality while delaying functional and radiological injury progression: out of 17 rats per condition, 2 control vs. 8 imatinib-treated rats survived until the end of the experiment (P = 0.02). Imatinib attenuated edema after lung injury (P < 0.05), and survival time in both groups was negatively correlated with increased lung mass (R2 = 0.70) as well as other physiological and CT parameters. Capillary leak (BAL protein concentration) was significantly lower in the treated group (P = 0.04). Peak drug concentration was reached after 70 min, and the drug half-life was 150 min. Imatinib decreased both mortality and lung injury severity in mechanically ventilated rats. Pharmacological inhibition of edema could be used during mechanical ventilation to improve the severity and outcome of lung injury.

Fatal diving: could it be an immersion pulmonary edema? Case report

Immersion pulmonary edema is a rare, underrecognized, and potentially lethal pathology developing during scuba diving and other immersion-related activities (swimming or apnoea). Physiopathology is complex and not fully understood, but its mechanisms involve an alteration of the alveolo-capillary barrier caused by transcapillary pressure elevation during immersion, leading to an accumulation of fluid and blood in the alveolar space. Diagnosis remains a challenge for clinicians and forensic practionner. The symptoms begin during ascent, with cough, frothy sputum, and hemoptysis. Auscultation reveals signs of pulmonary edema. Pulmonary CT scan, which is the radiological exam of choice, shows ground glass opacities and interlobular thickening, eventually demonstrating a patterned distribution, likely in the anterior segments of both lungs. Apart from the support of vital functions, there is no specific treatment and hyperbaric oxygen therapy is not systematically recommended. We present a case of fatal IPE occurring in a recreational diver who unfortunately died shortly after his last dive. Diagnosis was made after complete forensic investigations including post-mortem-computed tomography, complete forensic autopsy, histological examination, and toxicological analysis.

Pulmonary toxicity of sodium dichloroisocyanurate after intratracheal instillation in sprague-dawley rats

In water, sodium dichloroisocyanurate (NaDCC), a source for chlorine gas generation, releases free available chlorine in the form of hypochlorous acid, a strong oxidizing agent. NaDCC has been used as a disinfectant in humidifiers; however, its inhalation toxicity is a concern. Seven-week-old rats were exposed to NaDCC doses of 100, 500, and 2500 μg·kg^-1 body weight by intratracheal instillation (ITI) to investigate pulmonary toxicity. The rats were sacrificed at 1 d (exposure group) or 14 d (recovery group) after ITI. Despite a slight decrease in body weight after exposure, there was no statistically significant difference between the control and NaDCC-treated groups. A significant increase in the total protein level of the bronchoalveolar lavage fluid (BALF) was observed in the exposure groups. Lactate dehydrogenase leakage into the BALF increased significantly (p < 0.01) in the exposure groups; however, recovery was observed after 14 d. The measurement of cytokines in the BALF samples indicated a significant increase in interleukin (IL)-6 in the exposure group and IL-8 in the recovery group. Histopathological examination revealed inflammatory foci and pulmonary edema around the terminal bronchioles and alveoli. This study demonstrated that ITI of NaDCC induced reversible pulmonary edema and inflammation without hepatic involvement in rats.

Vanillin Attenuates Cadmium-Induced Lung Injury Through Inhibition of Inflammation and Lung Barrier Dysfunction Through Activating AhR

Vanillin, the main constituents of vanillin beans, has been reported to exhibit anti-inflammatory effects. However, the effects of vanillin on the cadmium-induced lung injury are still unclear. Therefore, we assay whether vanillin has potential preventive activity on cadmium-induced lung injury in mice. Mice were given vanillin (5, 10, 20 mg/kg) and treated with cadmium for 7 days. The detection data of vanillin on lung tissue changes were analyzed after the cadmium treatment. The results displayed that vanillin obviously decreased the lung histological alterations and myeloperoxidase (MPO) activity. Vanillin also suppressed the levels of TNF-α, IL-1β, and IL-6 in BALF. Furthermore, vanillin prevented cadmium-induced NF-κB activation and upregulation the expression of tight junction protein ZO-1 and occludin. In addition, vanillin significantly increased the expression of aryl hydrocarbon receptor (AhR), and inhibition of AhR by its agonist could reverse the protective effects of vanillin on cadmium-induced lung injury. To sum up, vanillin could be a potential drug for the treatment of cadmium-induced lung injury.

Blocking SphK1/S1P/S1PR1 Signaling Pathway Alleviates Lung Injury Caused by Sepsis in Acute Ethanol Intoxication Mice

Acute ethanol intoxication increases the risk of sepsis and aggravates the symptoms of sepsis and lung injury. Therefore, this study aimed to explore whether sphingosine kinase 1 (SphK1)/sphingosine-1-phosphate (S1P)/S1P receptor 1 (S1PR1) signaling pathway functions in lung injury caused by acute ethanol intoxication-enhanced sepsis, as well as its underlying mechanism. The acute ethanol intoxication model was simulated by intraperitoneally administering mice with 32% ethanol solution, and cecal ligation and puncture (CLP) was used to construct the sepsis model. The lung tissue damage was observed by hematoxylin-eosin (H&E) staining, and the wet-to-dry (W/D) ratio was used to evaluate the degree of pulmonary edema. Inflammatory cell counting and protein concentration in bronchoalveolar lavage fluid (BALF) were, respectively, detected by hemocytometer and bicinchoninic acid (BCA) method. The levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and IL-18 in BALF were detected by their commercial enzyme-linked immunosorbent assay (ELISA) kits. The myeloperoxidase (MPO) activity and expression of apoptosis-related proteins and SphK1/S1P/S1PR1 pathway-related proteins were, respectively, analyzed by MPO ELISA kit and Western blot analysis. The cell apoptosis in lung tissues was observed by TUNEL assay. Acute ethanol intoxication (EtOH) decreased the survival rate of mice and exacerbated the lung injury caused by sepsis through increasing pulmonary vascular permeability, neutrophil infiltration, release of inflammatory factors, and cell apoptosis. In addition, EtOH could activate the SphK1/S1P/S1PR1 pathway in CLP mice. However, PF-543, as a specific inhibitor of SphK1, could partially reverse the deleterious effects on lung injury of CLP mice. PF-543 alleviated lung injury caused by sepsis in acute ethanol intoxication rats by suppressing the SphK1/S1P/S1PR1 signaling pathway.

The prevalence and clinical features of pulmonary embolism in patients with AE-COPD: A meta-analysis and systematic review

BACKGROUND

The prevalence of pulmonary embolism (PE) in the acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) is highly controversial. We conducted a systematic review and meta-analysis to summarize the epidemiology and characteristics of PE with AE-COPD for current studies.

METHODS

We searched the PubMed, EMBASE, Cochrane Library and Web of Science databases for studies published prior to October 21, 2020. Pooled proportions with 95% confidence intervals (95% CIs) were calculated using a random effects model. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals were used as effect measures for dichotomous and continuous variables, respectively.

RESULTS

A total of 17 studies involving 3170 patients were included. The prevalence of PE and deep vein thrombosis (DVT) in AE-COPD patients was 17.2% (95% CI: 13.4%-21.3%) and 7.1% (95% CI: 3.7%-11.4%%), respectively. Dyspnea (OR = 6.77, 95% CI: 1.97-23.22), pleuritic chest pain (OR = 3.25, 95% CI: 2.06-5.12), lower limb asymmetry or edema (OR = 2.46, 95% CI:1.51-4.00), higher heart rates (MD = 20.51, 95% CI: 4.95-36.08), longer hospital stays (MD = 3.66, 95% CI: 3.01-4.31) were associated with the PE in the AE-COPD patients. Levels of D-dimer (MD = 1.51, 95% CI: 0.80-2.23), WBC counts (MD = 1.42, 95% CI: 0.14-2.70) were significantly higher and levels of PaO2 was lower (MD = -17.20, 95% CI: -33.94- -0.45, P<0.05) in the AE-COPD with PE group. The AE-COPD with PE group had increased risk of fatal outcome than the AE-COPD group (OR = 2.23, 95% CI: 1.43-3.50).

CONCLUSIONS

The prevalence of PE during AE-COPD varies considerably among the studies. AE-COPD patients with PE experienced an increased risk of death, especially among the ICU patients. Understanding the potential risk factors for PE may help clinicians identify AE-COPD patients at increased risk of PE.

PROSPERO REGISTRATION NUMBER

CRD42021226568.

Glyphosate and Polyoxyethyleneamine Ingestion Leading to Renal, Hepatic, and Pulmonary Failure

ABSTRACT

Glyphosate is an organophosphorus compound and the active ingredient in commonly used herbicides, whereas polyoxyethyleneamine (POEA) is a nonionic surfactant often coupled with glyphosate in these herbicides to increase their efficacy. Cases of glyphosate-POEA ingestion have shown a variety of outcomes, ranging from skin and mucosal surface irritation to death. Here, we report mortality after ingestion of at least 237 mL of an herbicide confirmed to contain both glyphosate and POEA. The decedent's electronic medical record indicates presentation to the emergency department shortly after ingestion and rapid decompensation, with death occurring on the fourth day of admission. The autopsy report showed extensive pulmonary edema and congestion with no alimentary tract abnormalities. Microscopically, airway inflammation, edema, and hemorrhage were shown as well as pericentral necrosis and macrovascular hepatic steatosis. This case is unusual for several reasons including the fatal outcome in a young 30-year-old patient, the large volume of the herbicide consumed, the associated large volume aspirated, and the lung pathology associated with exposure to glyphosate-POEA since inhalation, and in this case, aspiration is an uncommon route of glyphosate-POEA exposure. This report therefore offers rare respiratory tract pathological findings and the clinical course after aspiration of a large volume of glyphosate-POEA.

hucMSC Conditioned Medium Ameliorate Lipopolysaccharide-Induced Acute Lung Injury by Suppressing Oxidative Stress and Inflammation via Nrf2/NF-κB Signaling Pathway

Acute lung injury (ALI) is a common clinical syndrome in the cardiac intensive care unit with a high mortality rate. Inflammation and oxidative stress have been reported to play a crucial role in the development of ALI. Previous studies have shown that human umbilical cord mesenchymal stem cells (hucMSCs) have anti-inflammatory and antioxidative effects in various diseases. However, the anti-inflammatory and antioxidative effects of the hucMSC conditioned medium (CM) on LPS-induced ALI remain unclear. Therefore, in this study, we assessed whether the hucMSC conditioned medium could attenuate LPS-induced ALI and the underlying mechanisms. Mice were randomly divided into four groups: the control group, PBS group, LPS+PBS group, and LPS+CM group. The lung histopathology and bronchoalveolar lavage fluid (BALF) were analyzed after intervention. The Nrf2/NF-κB signaling pathway and its downstream target genes were tested, and the cytokines and growth factors in CM were also measured. The results showed that CM significantly attenuated the histological alterations; decreased the wet/dry weight ratio; reduced the levels of MPO, MDA and ROS; increased SOD and GSH activity; and downregulated the level of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α. Furthermore, CM promoted the expression of Nrf2 and its target genes NQ01, HO-1, and GCLC and inhibited the expression of NF-κB and its target genes IL-6, IL-1β, and TNF-α. These effects may be closely related to the large amounts of cytokines and growth factors in the CM. In conclusion, our results demonstrated that CM could attenuate LPS-induced ALI, probably due to inhibition of inflammation and oxidative stress via the Nrf2/NF-κB signaling pathway.

Simvastatin attenuates acute lung injury by activation of A2B adenosine receptor

To explore the protective mechanism of simvastatin in acute lung injury (ALI), the lipopolysaccharide (LPS) induced (5 mg/kg) ALI rat model was used to examine the effects of simvastatin. Following simvastatin treatment, the histopathological evaluation of lung tissues was made using hematoxylin and eosin (H&E) staining. Also, myeloperoxidase (MPO) activity and the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-10 were determined by ELISA. Blood gas analyses of arterial blood samples were performed to assess the pulmonary gas exchange. Moreover, the neutrophil count and total protein content were determined in the bronchoalveolar lavage (BAL) fluid. The ratio of wet lung to dry lung (W/D) and the alveolar fluid clearance (AFC) were calculated to estimate the severity of edema. Lastly, the levels of A2BAR, CFTR, claudin4, and claudin18 were also measured by qRT-PCR and Western blotting. Simvastatin treatment, in a dose-related manner, markedly improved the lung histological injury and decreased the levels of TNF-α, IL-1β, and increased IL-10 in LPS induced ALI. Also, pulmonary neutrophil count was alleviated. Besides, a decreased ratio of W/D lung also confirmed the simvastatin intervention. Notably, simvastatin reduced the levels of A2BAR, CFTR, and claudin18 but upregulated claudin4 in lung tissues. Additionally, treatment with PSB1115, an antagonist of A2BAR, countered the protective effect of simvastatin in ALI. Our study demonstrates that simvastatin has a protective effect against LPS-induced ALI by activating A2BAR and should be exploited as a novel therapeutic target for the treatment of ALI.

Circulating BMP9 Protects the Pulmonary Endothelium during Inflammation-induced Lung Injury in Mice

Rationale: Pulmonary endothelial permeability contributes to the high-permeability pulmonary edema that characterizes acute respiratory distress syndrome. Circulating BMP9 (bone morphogenetic protein 9) is emerging as an important regulator of pulmonary vascular homeostasis. Objectives:To determine whether endogenous BMP9 plays a role in preserving pulmonary endothelial integrity and whether loss of endogenous BMP9 occurs during LPS challenge. Methods: A BMP9-neutralizing antibody was administrated to healthy adult mice, and lung vasculature was examined. Potential mechanisms were delineated by transcript analysis in human lung endothelial cells. The impact of BMP9 administration was evaluated in a murine acute lung injury model induced by inhaled LPS. Levels of BMP9 were measured in plasma from patients with sepsis and from endotoxemic mice. Measurements and Main Results: Subacute neutralization of endogenous BMP9 in mice (N = 12) resulted in increased lung vascular permeability (P = 0.022), interstitial edema (P = 0.0047), and neutrophil extravasation (P = 0.029) compared with IgG control treatment (N = 6). In pulmonary endothelial cells, BMP9 regulated transcriptome pathways implicated in vascular permeability and cell-membrane integrity. Augmentation of BMP9 signaling in mice (N = 8) prevented inhaled LPS-induced lung injury (P = 0.0027) and edema (P < 0.0001). In endotoxemic mice (N = 12), endogenous circulating BMP9 concentrations were markedly reduced, the causes of which include a transient reduction in hepatic BMP9 mRNA expression and increased elastase activity in plasma. In human patients with sepsis (N = 10), circulating concentratons of BMP9 were also markedly reduced (P < 0.0001). Conclusions: Endogenous circulating BMP9 is a pulmonary endothelial-protective factor, downregulated during inflammation. Exogenous BMP9 offers a potential therapy to prevent increased pulmonary endothelial permeability in lung injury.

Complete Clinicopathological Case Report of a Young Patient Dying of COVID-19-Related Stroke

ABSTRACT

The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic has revealed diverse neurological manifestations of coronavirus disease 2019 (COVID-19). This case report begins with a background review of the neurological effects of COVID-19, focusing on stroke, neuroinflammation, and coagulopathy. It then describes the clinical course and autopsy findings of a young patient presenting with COVID-19-associated stroke. The formal neuropathological examination is presented, along with the systemic and brain histological features. Interesting aspects include multiterritory hemorrhagic infarctions, microinfarcts throughout the cortex and white matter, and prominent mixed inflammatory cell cuffing of intracerebral blood vessels distant from the infarcts.

Lipoxin A4 protects against paraquat‑induced acute lung injury by inhibiting the TLR4/MyD88‑mediated activation of the NF‑κB and PI3K/AKT pathways

Paraquat (PQ) causes serious oxidative stress and inflammatory responses, particularly to the lungs. Since lipoxin A4 (LXA4) functions as an anti‑inflammatory mediator, the present study aimed to explore its effects on PQ‑induced acute lung injury (ALI) and to elucidate the possible underlying mechanisms. PQ was administered to male SD rats and RAW264.7 cells to establish a model of poisoning, and LXA4 was used as an intervention drug. LXA4 treatment attenuated PQ‑induced lung injury, and this was accompanied by decreased tumor necrosis factor (TNF)‑α and interleukin (IL)‑1β secretion levels, and reduced oxidative stress damage. Additionally, LXA4 treatment inhibited the activation of the inflammation‑related signaling molecules, Toll‑like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor (NF)‑κB p65, p‑phosphoinositide 3‑kinase (PI3K) and p‑AKT. Furthermore, the in vitro experiments further confirmed that the beneficial effects of LXA4 on PQ‑induced damage were TLR4‑dependent. Hence, the present study demonstrated that LXA4 attenuated PQ‑induced toxicity in lung tissue and RAW264.7 macrophages, and that this protective effect may be closely related to the mitigation of inflammatory responses, oxidative stress damage and the TLR4/MyD88‑mediated activation of the PI3K/AKT/NF‑κB pathway.

Endothelial cells and SARS-CoV-2: An intimate relationship

Angiotensin-converting enzyme 2 (ACE2) is an important player of the renin-angiotensin-aldosterone system (RAAS) in regulating the conversion of angiotensin II into angiotensin (1-7). While expressed on the surface of human cells, such as lung, heart, kidney, neurons, and endothelial cells (EC), ACE2 is the entry receptor for SARS-CoV-2. Here, we would like to highlight that ACE2 is predominant on the EC membrane. Many of coronavirus disease 2019 (COVID-19) symptoms have been associated with the large recruitment of immune cells, directly affecting EC. Additionally, cytokines, hypoxia, and complement activation can trigger the activation of EC leading to the coagulation cascade. The EC dysfunction plus the inflammation due to SARS-CoV-2 infection may lead to abnormal coagulation, actively participating in thrombo-inflammatory processes resulting in vasculopathy and indicating poor prognosis in patients with COVID-19. Considering the intrinsic relationship between EC and the pathophysiology of SARS-CoV-2, EC-associated therapies such as anticoagulants, fibrinolytic drugs, immunomodulators, and molecular therapies have been proposed. In this review, we will discuss the role of EC in the lung inflammation and edema, in the disseminate coagulation process, ACE2 positive cancer patients, and current and future EC-associated therapies to treat COVID-19.

17β-Estradiol Treatment Protects Lungs Against Brain Death Effects in Female Rat Donor

BACKGROUND

Brain death (BD) affects the viability of lungs for transplantation. A correlation exists between high-lung inflammation after BD and the decrease in female sex hormones, especially estradiol. Therefore, we investigated the effects of 17β-estradiol (E2) treatment on the lungs of female brain dead rats.

METHODS

Female Wistar rats were divided into 4 groups: BD (submitted to BD for 6 h), sham (false operated), E2-T0 (treated with E2 immediately after BD; 50 μg/mL, 2 mL/h), and E2-T3 (treated with E2 after 3 h of BD; 50 μg/mL, 2 mL/h). Lung edema, hemorrhage, and leukocyte infiltration were analyzed. Adhesion molecules were evaluated, and analysis of NO synthase gene and protein expression was performed using real-time PCR and immunohistochemistry, respectively. Release of chemokines and matrix degradation in the lungs was analyzed.

RESULTS

BD increased leukocyte infiltration, as shown by intravital microscopy (P = 0.017), bronchoalveolar lavage cell count (P = 0.016), the release of inflammatory mediators (P = 0.02), and expression of adhesion molecules. BD also increased microvascular permeability and the expression and activity of matrix metalloproteinase-9 in the lungs. E2 treatment reduced leukocyte infiltration, especially in the E2-T3 group, release of inflammatory mediators, adhesion molecules, and matrix metalloproteinase activity in the lungs.

CONCLUSIONS

E2 treatment was successful in controlling the lung inflammatory response in females submitted to BD. Our results suggest that E2 directly decreases the release of chemokines, restraining cell traffic into the lungs. Thus, E2 has a therapeutic potential, and its role in improving donor lung quality should be explored further.

Pulmonary and vascular effects of acute ozone exposure in diabetic rats fed an atherogenic diet

Air pollutants may increase risk for cardiopulmonary disease, particularly in susceptible populations with metabolic stressors such as diabetes and unhealthy diet. We investigated effects of inhaled ozone exposure and high-cholesterol diet (HCD) in healthy Wistar and Wistar-derived Goto-Kakizaki (GK) rats, a non-obese model of type 2 diabetes. Male rats (4-week old) were fed normal diet (ND) or HCD for 12 weeks and then exposed to filtered air or 1.0 ppm ozone (6 h/day) for 1 or 2 days. We examined pulmonary, vascular, hematology, and inflammatory responses after each exposure plus an 18-h recovery period. In both strains, ozone induced acute bronchiolar epithelial necrosis and inflammation on histopathology and pulmonary protein leakage and neutrophilia; the protein leakage was more rapid and persistent in GK compared to Wistar rats. Ozone also decreased lymphocytes after day 1 in both strains consuming ND (~50%), while HCD increased circulating leukocytes. Ozone increased plasma thrombin/antithrombin complexes and platelet disaggregation in Wistar rats on HCD and exacerbated diet effects on serum IFN-γ, IL-6, KC-GRO, IL-13, and TNF-α, which were higher with HCD (Wistar>GK). Ex vivo aortic contractility to phenylephrine was lower in GK versus Wistar rats at baseline(~30%); ozone enhanced this effect in Wistar rats on ND. GK rats on HCD had higher aortic e-NOS and tPA expression compared to Wistar rats. Ozone increased e-NOS in GK rats on ND (~3-fold) and Wistar rats on HCD (~2-fold). These findings demonstrate ways in which underlying diabetes and HCD may exacerbate pulmonary, systemic, and vascular effects of inhaled pollutants.

Hydrogen Attenuates Endotoxin-Induced Lung Injury by Activating Thioredoxin 1 and Decreasing Tissue Factor Expression

Endotoxin-induced lung injury is one of the major causes of death induced by endotoxemia, however, few effective therapeutic options exist. Hydrogen inhalation has recently been shown to be an effective treatment for inflammatory lung injury, but the underlying mechanism is unknown. In the current study we aim to investigate how hydrogen attenuates endotoxin-induced lung injury and provide reference values for the clinical application of hydrogen. LPS was used to establish an endotoxin-induced lung injury mouse model. The survival rate and pulmonary pathologic changes were evaluated. THP-1 and HUVECC cells were cultured in vitro. The thioredoxin 1 (Trx1) inhibitor was used to evaluate the anti-inflammatory effects of hydrogen. Hydrogen significantly improved the survival rate of mice, reduced pulmonary edema and hemorrhage, infiltration of neutrophils, and IL-6 secretion. Inhalation of hydrogen decreased tissue factor (TF) expression and MMP-9 activity, while Trx1 expression was increased in the lungs and serum of endotoxemia mice. LPS-stimulated THP-1 and HUVEC-C cells in vitro and showed that hydrogen decreases TF expression and MMP-9 activity, which were abolished by the Trx1 inhibitor, PX12. Hydrogen attenuates endotoxin-induced lung injury by decreasing TF expression and MMP-9 activity via activating Trx1. Targeting Trx1 by hydrogen may be a potential treatment for endotoxin-induced lung injury.

Survival and Pulmonary Injury After Neonatal Sepsis: PD1/PDL1's Contributions to Mouse and Human Immunopathology

Morbidity and mortality associated with neonatal sepsis remains a healthcare crisis. PD1-/- neonatal mice endured experimental sepsis, in the form of cecal slurry (CS), and showed improved rates of survival compared to wildtype (WT) counterparts. End-organ injury, particularly of the lung, contributes to the devastation set forth by neonatal sepsis. PDL1-/- neonatal mice, in contrast to PD1-/- neonatal mice did not have a significant improvement in survival after CS. Because of this, we focused subsequent studies on the impact of PD1 gene deficiency on lung injury. Here, we observed that at 24 h post-CS (but not at 4 or 12 h) there was a marked increase in pulmonary edema (PE), neutrophil influx, myeloperoxidase (MPO) levels, and cytokine expression sham (Sh) WT mice. Regarding pulmonary endothelial cell (EC) adhesion molecule expression, we observed that Zona occludens-1 (ZO-1) within the cell shifted from a membranous location to a peri-nuclear location after CS in WT murine cultured ECs at 24hrs, but remained membranous among PD1-/- lungs. To expand the scope of this inquiry, we investigated human neonatal lung tissue. We observed that the lungs of human newborns exposed to intrauterine infection had significantly higher numbers of PD1+ cells compared to specimens who died from non-infectious causes. Together, these data suggest that PD1/PDL1, a pathway typically thought to govern adaptive immune processes in adult animals, can modulate the largely innate neonatal pulmonary immune response to experimental septic insult. The potential future significance of this area of study includes that PD1/PDL1 checkpoint proteins may be viable therapeutic targets in the septic neonate.

6-Gingerol attenuates ventilator-induced lung injury via anti-inflammation and antioxidative stress by modulating the PPARγ/NF-κBsignalling pathway in rats

Although mechanical ventilation (MV) is indispensable to life-support therapy in critically ill patients, it may promote or aggravatelunginjury known asventilator-inducedlunginjury(VILI). 6-Gingerol is the principal ingredient of ginger with potential anti-inflammatory and antioxidant properties in various diseases. Nevertheless, the role and mechanism of 6-gingerol in the process of VILI has not been explicitly investigated. In the study, we found that pre-treatment with 6-gingerol significantly improved the histological changes and pulmonary oedema, inhibited neutrophil accumulation and the release of early pro-inflammatory cytokines and MPO, and reduced oxidative stress reactions after high MV. Moreover, 6-gingerol treatment also increased PPARγ expression and decreased NF-κB activation in rats subjected to high MV. Furthermore, GW9662, a specific PPARγ inhibitor, was demonstrated to activatethe NF-κB pathway and cancele the protective role of 6-gingerol in VILI. This indicates that 6-gingerol exerted anti-inflammatory and antioxidative stress effects in VILI by activating PPARγ and inhibiting the NF-κBsignalling pathway.

New Mexico's COVID-19 Experience

ABSTRACT

The 2019 novel coronavirus disease (COVID-19) has spread worldwide, infiltrating, infecting, and devastating communities in all locations of varying demographics. An overwhelming majority of published literature on the pathologic findings associated with COVID-19 is either from living clinical cohorts or from autopsy findings of those who died in a medical care setting, which can confound pure disease pathology. A relatively low initial infection rate paired with a high biosafety level enabled the New Mexico Office of the Medical Investigator to conduct full autopsy examinations on suspected COVID-19-related deaths. Full autopsy examination on the first 20 severe acute respiratory syndrome coronavirus 2-positive decedents revealed that some extent of diffuse alveolar damage in every death due to COVID-19 played some role. The average decedent was middle-aged, male, American Indian, and overweight with comorbidities that included diabetes, ethanolism, and atherosclerotic and/or hypertensive cardiovascular disease. Macroscopic thrombotic events were seen in 35% of cases consisting of pulmonary thromboemboli and coronary artery thrombi. In 2 cases, severe bacterial coinfections were seen in the lungs. Those determined to die with but not of severe acute respiratory syndrome coronavirus 2 infection had unremarkable lung findings.

Thal protects against paraquat-induced lung injury through a microRNA-141/HDAC6/IκBα-NF-κB axis in rat and cell models

The protective functions of thalidomide in paraquat (PQ)-induced injury have been reported. But the mechanisms remain largely unknown. In this research, a PQ-treated rat model was established and further treated with thalidomide. Oedema and pathological changes, oxidative stress, inflammation, fibrosis and cell apoptosis in rat lungs were detected. A PQ-treated RLE-6TN cell model was constructed, and the viability and apoptosis rate of cells were measured. Differentially expressed microRNAs (miRNAs) after thalidomide administration were screened out. Binding relationship between miR-141 and histone deacetylase 6 (HDAC6) was validated. Altered expression of miR-141 and HDAC6 was introduced to identify their involvements in thalidomide-mediated events. Consequently, thalidomide administration alone exerted no damage to rat lungs; in addition it reduced PQ-induced oedema. The oxidative stress, inflammation and cell apoptosis in rat lungs were reduced by thalidomide. In RLE-6TN cells, thalidomide increased cell viability and decreased apoptosis. miR-141 was responsible for thalidomide-mediated protective events by targeting HDAC6. Overexpression of HDAC6 blocked the protection of thalidomide against PQ-induced injury via activating the IkBα-NF-κB signalling pathway. Collectively, this study evidenced that thalidomide protects lung tissues from PQ-induced injury through a miR-141/HDAC6/IkBα-NF-κB axis.

Astragaloside IV alleviates PM2.5-induced lung injury in rats by modulating TLR4/MyD88/NF-κB signalling pathway

OBJECTIVE

Astragaloside IV (AS IV) is antioxidant and anti-inflammatory product, which is extracted from the Chinese herb Astragalus membranaceus. It is widely used in a variety of inflammatory diseases. The research was to explored the protective effects of AS IV against lung injury induced by particulate matter 2.5 (PM2.5) in vivo.

SUBJECTS AND METHODS

Thirty-five male Sprague-Dawley rats were randomly divided into five groups (n=7 per group). (1) Normal saline group (NS), (2) AS IV group (AS) (100 mg/kg), (3) PM2.5 group (PM2.5), (4) PM2.5 + AS IV group (ASL) (50 mg/kg), and (5) PM2.5 + AS IVgroup (ASH) (100 mg/kg). Rats were pre-treated with AS IV intraperitoneally (50 and 100 mg/kg/day) for three days. Then, PM2.5 (7.5 mg/kg) was given by intratracheal instillation to induce lung injury. Six hours after PM2.5 stimulation, the rats were euthanized. Bronchoalveolar lavage fluid (BALF) was collected for assay of cytokines. Lung tissue was collected for oxidative stress, histology, immunohistochemistry, transmission electron microscope, and western blot analyses.

RESULTS

AS IV alleviated PM2.5-induced lung injury by decreasing lung dry-wet ratio, reducing the level of interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) in BALF, and reduced oxidative stress response in lung tissue. Western blot results revealed that AS-IV regulated the expression of TLR4/MyD88/NF-κB pathway proteins in lung tissues.

CONCLUSION

AS IV mitigated PM2.5 induced lung injury by regulating the activity of TLR4/MyD88/NF-κB signalling pathway, reducing inflammatory and oxidative stress responses.

A synthetic chalcone derivative, compound 39, alleviates lipopolysaccharide-induced acute lung injury in mice

Our research group has previously synthesized various chalcone analogues. Of these analogues, compound 39 has been shown to exhibit potent antioxidative activities but its anti-inflammatory and anti-apoptosis effects remain unclear. Thus, the present study investigated the in vivo and in vitro effects and mechanisms of compound 39 in lipopolysaccharide (LPS)-induced acute lung injury (ALI). To induce ALI, the mice received LPS via a tracheal instillation 6 h after intragastric administration of compound 39 or vehicle. Histological changes, the lung wet/dry weight ratio, and the amounts of protein and inflammatory cells in the broncho-alveolar lavage (BAL) fluid were assessed after 24 h. Additionally, to determine its underlying mechanisms, Western blot and immunofluorescence analyses were used. Moreover, the in vitro effects of compound 39 were also investigated. In the in vivo experiment, compound 39 markedly alleviated histopathological alterations, lung edema, and protein leakage, and exhibited potent anti-inflammatory effects. In the in vitro experiments, compound 39 dose-dependently reduced the levels of pro-inflammatory cytokines and reactive oxygen species. The results suggested that the anti-inflammatory effects of compound 39 were due to suppression of the mitogen-activated protein kinase (MAPK)/nuclear factor κB (NF-κB) pathway. Compound 39 also enhanced the protein levels of Bcl-2 and reduced the protein levels of Bax and cleaved caspase-3. The present study confirmed the anti-inflammatory, oxy-radical prohibitive, and anti-apoptosis activities of compound 39 against LPS-induced tissue and cell damage, and revealed the mechanisms underlying those processes.

Pulmonary edema following shoulder arthroscopy under general anesthesia with nerve block: An observational study

ABSTRACT

Shoulder arthroscopy requires a large of irrigation for a better surgical view, leading circulatory overload. This study was performed to prove whether pulmonary edema will be lead by a large of irrigation.General anesthesia with interscalene block was induced before operation. The primary outcome was ultrasound evaluation of B lines from the time before nerve block to the time 10 hours after operation. The secondary outcomes included oxygenation index, arterial partial pressure of carbon dioxide, visual analogue scale, muscle strength grade.A total of 93 patients were evaluated. Before surgery, B lines failed to be detected. While the highest total incidence of B lines was 49.4%, occurred at 4 hours after surgery. The highest incidences of severe and moderate pulmonary edema were 3.2% (P = .081) and 9.7% (P = .002), respectively. B lines were also found on both the affected and healthy side. During operation, the incidence of type 1 respiratory failure was 5.4% (P = .023) and that of both type 1 and 2 respiratory failure were 6.5% (P = .013). Pain was relieved in 6 hours after surgery (VAS < 3). At 12 hours after operation, the VAS of resting and motion were 4.68 ± 2.27, 6.90 ± 2.43, respectively. While the grade of muscle strength was 4.48 ± 0.51 at 12 hours after operation.There is a high incidence of pulmonary edema in shoulder arthroscopy, and ultrasound is a convenient tool to evaluate this complication. Pain is relieved in 6 hours after surgery by nerve block. While muscle strength can also recover at 12 hours after surgery.

Renin-Angiotensin System: An Important Player in the Pathogenesis of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is characterized by massive inflammation, increased vascular permeability and pulmonary edema. Mortality due to ARDS remains very high and even in the case of survival, acute lung injury can lead to pulmonary fibrosis. The renin-angiotensin system (RAS) plays a significant role in these processes. The activities of RAS molecules are subject to dynamic changes in response to an injury. Initially, increased levels of angiotensin (Ang) II and des-Arg⁹-bradykinin (DABK), are necessary for an effective defense. Later, augmented angiotensin converting enzyme (ACE) 2 activity supposedly helps to attenuate inflammation. Appropriate ACE2 activity might be decisive in preventing immune-induced damage and ensuring tissue repair. ACE2 has been identified as a common target for different pathogens. Some Coronaviruses, including SARS-CoV-2, also use ACE2 to infiltrate the cells. A number of questions remain unresolved. The importance of ACE2 shedding, associated with the release of soluble ACE2 and ADAM17-mediated activation of tumor necrosis factor-α (TNF-α)-signaling is unclear. The roles of other non-classical RAS-associated molecules, e.g., alamandine, Ang A or Ang 1-9, also deserve attention. In addition, the impact of established RAS-inhibiting drugs on the pulmonary RAS is to be elucidated. The unfavorable prognosis of ARDS and the lack of effective treatment urge the search for novel therapeutic strategies. In the context of the ongoing SARS-CoV-2 pandemic and considering the involvement of humoral disbalance in the pathogenesis of ARDS, targeting the renin-angiotensin system and reducing the pathogen's cell entry could be a promising therapeutic strategy in the struggle against COVID-19.

The conventional isoproterenol-induced heart failure model does not consistently mimic the diaphragmatic dysfunction observed in patients

Heart failure (HF) impairs diaphragm function. Animal models realistically mimicking HF should feature both the cardiac alterations and the diaphragmatic dysfunction characterizing this disease. The isoproterenol-induced HF model is widely used, but whether it presents diaphragmatic dysfunction is unknown. However, indirect data from research in other fields suggest that isoproterenol could increase diaphragm function. The aim of this study was to test the hypothesis that the widespread rodent model of isoproterenol-induced HF results in increased diaphragmatic contractility. Forty C57BL/6J male mice were randomized into 2 groups: HF and healthy controls. After 30 days of isoproterenol infusion to establish HF, in vivo diaphragmatic excursion and ex vivo isolated diaphragm contractibility were measured. As compared with healthy controls, mice with isoproterenol-induced HF showed the expected changes in structural and functional echocardiographic parameters and lung edema. isoproterenol-induced HF increased in vivo diaphragm excursion (by ≈30%, p<0.01) and increased by ≈50% both ex vivo peak specific force (p<0.05) and tetanic force (p<0.05) at almost all 10–100 Hz frequencies (p<0.05), with reduced fatigue resistance (p<0.01) when compared with healthy controls. Expression of myosin genes encoding the main muscle fiber types revealed that Myh4 was higher in isoproterenol-induced HF than in healthy controls (p<0.05), suggesting greater distribution of type IIb fibers. These results show that the conventional isoproterenol-induced HF model increases diaphragm contraction, a finding contrary to what is observed in patients with HF. Therefore, this specific model seems limited for translational an integrative HF research, especially when cardio-respiratory interactions are investigated.

The protective effects of Thalictrum minus L. on lipopolysaccharide-induced acute lung injury

ETHNOPHARMACOLOGICAL RELEVANCE

Thalictrum minus L., a Mongolian folk medicinal plant, was applied for the treatment of bacterial and fungal infection, tuberculosis and lung inflammation.

AIM OF THE STUDY

The present work aims to elucidate the protective effects of Thalictrum minus L.(TML) against lipopolysaccharide (LPS)-induced acute lung injury and the underlying mechanisms.

METHODS

The mice model of acute lung injury was induced by LPS via endotracheal drip, and TML (10, 20, 40 mg/kg) were administered orally 1 h prior to LPS. The efficacy and molecular mechanisms in the presence or absence of TML were investigated.

RESULTS

We demonstrated that treatment with TML aqueous extract protected the mice from acute lung injury induced by LPS administration. TML significantly inhibited weight loss in mice, decreased the lung wet to dry weight (W/D) ratios and attenuated lung histopathological changes, such as infiltration of inflammatory cells and coagulation, pulmonary edema. Furthermore, we found that TML markedly reduced the LPS-induced inflammatory cytokines including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), decreased nitric oxide (NO), and increased superoxide dismutase (SOD) in bronchoalveolar lavage fluid (BALF), and effectively ameliorated LPS-induced increased total protein, leukocyte and macrophages in BALF. In addition, TML pronouncedly suppressed the activation of the MAPKs p38-NLRP3/caspase-1 and COX2, increased the expression of p-AMPK-Nrf2, and suppressed the expression of KEAP, apoptotic-related protein as well as autophagy.

CONCLUSIONS

These results suggested that TML ameliorated LPS-induced acute lung injury by inhibiting the release of inflammatory cytokines and reducing oxidative damage associated with the MAPKs p38-NLRP3/caspase-1 and COX2 signaling pathways, AMPK-Nrf2/KEAP signaling pathways, as well as apoptosis and autophagy.

Vascular Endothelial Growth Factor-121 Administration Mitigates Halogen Inhalation-Induced Pulmonary Injury and Fetal Growth Restriction in Pregnant Mice

Background Circulating levels of sFLT-1 (soluble fms-like tyrosine kinase 1), the extracellular domain of vascular endothelial growth factor (VEGF) receptor 1, and its ratio to levels of placental growth factor are markers of the occurrence and severity of preeclampsia. Methods and Results C57BL/6 pregnant mice on embryonic day 14.5 (E14.5), male, and non-pregnant female mice were exposed to air or to Br2 at 600 ppm for 30 minutes and were treated with vehicle or with VEGF-121 (100 μg/kg, subcutaneously) daily, starting 48 hours post-exposure. Plasma, bronchoalveolar lavage fluid, lungs, fetuses, and placentas were collected 120 hours post-exposure. In Br2-exposed pregnant mice, there was a time-dependent and significant increase in plasma levels of sFLT-1 which correlated with increases in mouse lung wet/dry weights and bronchoalveolar lavage fluid protein content. Supplementation of exogenous VEGF-121 improved survival and weight gain, reduced lung wet/dry weights, decreased bronchoalveolar lavage fluid protein levels, enhanced placental development, and improved fetal growth in pregnant mice exposed to Br2. Exogenous VEGF-121 administration had no effect in non-pregnant mice. Conclusions These results implicate inhibition of VEGF signaling driven by sFLT-1 overexpression as a mechanism of pregnancy-specific injury leading to lung edema, maternal mortality, and fetal growth restriction after bromine gas exposure.

Immersion pulmonary edema: case reports from Oceania

INTRODUCTION

We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive.

METHOD

Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded.

RESULTS

Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%.

CONCLUSIONS

Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.

Immersion pulmonary edema: an analysis of 31 cases from Oceania

AIM

To review incidents of immersion pulmonary edema (IPE) from Oceania, to determine the demographics, diving parameters, and comorbidities that may be related to this disorder.

METHOD

Incidents of IPE, most of which were documented by Divers Alert Network Asia-Pacific (DAN AP) or reported in our medical literature, were analyzed. They included interviews with the survivors and a review of available medical records. Only incidents diagnosed as IPE by specialist diving physicians or pathologists with experience in the investigation of diving accidents were included.

RESULTS

Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers, which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 msw for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities in this cohort. Medical comorbidities were recorded in 68%, with 42% being cardiac. The latter included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%.

CONCLUSION

IPE was more likely in middle-aged females, in experienced divers, and during ascent or after surfacing. Commonly reported associations such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, tight wetsuit, aspiration and certain medications were identified. This series supports the hypothesis that the elderly IPE subjects are likely to have comorbidities and be susceptible to IPE recurrences and fatalities unless the contributing factors can be identified and addressed.

Lung endothelial cell antigen cross-presentation to CD8+T cells drives malaria-associated lung injury

Malaria-associated acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are life-threatening manifestations of severe malaria infections. The pathogenic mechanisms that lead to respiratory complications, such as vascular leakage, remain unclear. Here, we confirm that depleting CD8+T cells with anti-CD8β antibodies in C57BL/6 mice infected with P. berghei ANKA (PbA) prevent pulmonary vascular leakage. When we transfer activated parasite-specific CD8+T cells into PbA-infected TCRβ-/- mice (devoid of all T-cell populations), pulmonary vascular leakage recapitulates. Additionally, we demonstrate that PbA-infected erythrocyte accumulation leads to lung endothelial cell cross-presentation of parasite antigen to CD8+T cells in an IFNγ-dependent manner. In conclusion, pulmonary vascular damage in ALI is a consequence of IFNγ-activated lung endothelial cells capturing, processing, and cross-presenting malaria parasite antigen to specific CD8+T cells induced during infection. The mechanistic understanding of the immunopathogenesis in malaria-associated ARDS and ALI provide the basis for development of adjunct treatments.

Roles of interleukin-11 during acute bacterial pneumonia

Interleukin-11 (IL-11) is an interleukin-6 (IL-6) family cytokine shown to play a protective role in acute inflammatory settings including systemic infection. In this study we addressed the role of IL-11 in acute bacterial pneumonia using a mouse model of E. coli pneumonia. Compared with other related cytokines, IL-11 protein was maintained at high levels in the lung at baseline, with only mild alterations in whole lung and BALF levels during acute infection. The primary source of IL-11 in the lung was the epithelium, but steady state production was not dependent on the inflammatory transcription factor nuclear factor kappa B in cells of either myeloid or epithelial lineage. Blockade of IL-11 with neutralizing antibodies resulted in a mild but significant decrease in neutrophil recruitment and increase in pulmonary edema during pneumonia, without detectable alterations in bacterial clearance. Exogenous IL-11 administration, however, had no effect at baseline or during infection. Overall, we conclude that maintenance of lung IL-11 concentrations may influence acute pulmonary inflammation during infection, albeit modestly.

MCP-1 promotes detrimental cardiac physiology, pulmonary edema, and death in the cpk model of polycystic kidney disease

Polycystic kidney disease (PKD) is characterized by slowly expanding renal cysts that damage the kidney, typically resulting in renal failure by the fifth decade. The most common cause of death in these patients, however, is cardiovascular disease. Expanding cysts in PKD induce chronic kidney injury that is accompanied by immune cell infiltration, including macrophages, which we and others have shown can promote disease progression in PKD mouse models. Here, we show that monocyte chemoattractant protein-1 [MCP-1/chemokine (C-C motif) ligand 2 (CCL2)] is responsible for the majority of monocyte chemoattractant activity produced by renal PKD cells from both mice and humans. To test whether the absence of MCP-1 lowers renal macrophage concentration and slows disease progression, we generated genetic knockout (KO) of MCP-1 in a mouse model of PKD [congenital polycystic kidney (cpk) mice]. Cpk mice are born with rapidly expanding renal cysts, accompanied by a decline in kidney function and death by postnatal day 21. Here, we report that KO of MCP-1 in these mice increased survival, with some mice living past 3 mo. Surprisingly, however, there was no significant difference in renal macrophage concentration, nor was there improvement in cystic disease or kidney function. Examination of mice revealed cardiac hypertrophy in cpk mice, and measurement of cardiac electrical activity via ECG revealed repolarization abnormalities. MCP-1 KO did not affect the number of cardiac macrophages, nor did it alleviate the cardiac aberrancies. However, MCP-1 KO did prevent the development of pulmonary edema, which occurred in cpk mice, and promoted decreased resting heart rate and increased heart rate variability in both cpk and noncystic mice. These data suggest that in this mouse model of PKD, MCP-1 altered cardiac/pulmonary function and promoted death outside of its role as a macrophage chemoattractant.

Methamphetamine-related post-mortem cases in Bangkok, Thailand

Introduction

This study investigated variables associated with methamphetamine-related deaths in Thailand.

Methods

This study used data obtained from methamphetamine-related autopsy cases over a six-year period from 2011 to 2016. From the data available during this period, considered variables included: demographic, toxicological and histopathological profiles. Methamphetamine blood concentration calculations and myoglobin immunostainings in kidney samples were also carried out. Statistical analysis and tests of significance were conducted using a paired-sample t-test, adopting a p-value of 0.05.

Results

A total of 61 methamphetamine-related cases were reviewed. Of several pathological findings, cardiovascular pathological findings were the most common. Cases were divided into a non-trauma group ( n = 19; 31.15%) and a trauma group ( n  =  42; 68.85%), and it was found that methamphetamine blood concentrations of non-trauma cases were largely in therapeutic ranges. The differences between methamphetamine concentrations of trauma and non-trauma groups were not statistically significant ( p > 0.05). Immunostainings for myoglobin in kidney samples were positive in two non-trauma cases, which is suggestive of methamphetamine-induced rhabdomyolysis.

Conclusions

Methamphetamine intoxication causes cardiac toxicity and can cause death. However, methamphetamine quantitation, autopsy findings and scene investigations are considered altogether in determination of cause of death due to many factors such as drug tolerances. Myoglobin immunostaining was found to be a useful tool in determining cause of death.

Fluid restriction reduces pulmonary edema in a model of acute lung injury in mechanically ventilated rats

Experimental acute lung injury models are often used to increase our knowledge on the acute respiratory distress syndrome (ARDS), however, existing animal models often do not take into account the impact of specific fluid strategies on the development of lung injury. In contrast, the current literature strongly suggests that fluid management strategies have a significant impact on clinical outcome of patients with ARDS. Thus, it is important to characterize the role of fluid management strategies in experimental models of lung injury. In this study we investigated the effect of two different fluid strategies on commonly used outcome variables in a short-term model of acute lung injury, in relation to age. Infant (2–3 weeks) and adult (3–4 months) Wistar rats received intratracheal instillations of lipopolysaccharide and 24 hours later were mechanically ventilated for 6 hours. During mechanical ventilation, rats from both age groups were randomized to either a standard or conservative intravenous fluid strategy. We found that the hemodynamic response in infant and adult rats was similar in both fluid strategies. Lung wet-to-dry ratios were lower in adult, but not in infant rats receiving the conservative fluid strategy as compared to the standard fluid strategy. There were age-related differences in markers of alveolar capillary barrier disruption and alveolar fluid clearance, yet these were unaffected by fluid strategy. Finally, we found significantly higher IL-1β and TNF-α concentrations in the adult rats treated with the conservative as compared to the standard fluid regimen. In conclusion, the choice of fluid strategy in mechanically ventilated rats with experimental LPS-induced acute lung injury has a significant effect on pulmonary extravascular water, an important and well-recognized lung injury marker, and on the local pro-inflammatory cytokine profiles. We advocate the use of a more uniform, conservative, fluid strategy regimen in experimental models of acute lung injury.

Pressure-dependent NOS activation contributes to endothelial hyperpermeability in a model of acute heart failure

Aims: Acute increases in left ventricular end diastolic pressure (LVEDP) can induce pulmonary edema (PE). The mechanism(s) for this rapid onset edema may involve more than just increased fluid filtration. Lung endothelial cell permeability is regulated by pressure-dependent activation of nitric oxide synthase (NOS). Herein, we demonstrate that pressure-dependent NOS activation contributes to vascular failure and PE in a model of acute heart failure (AHF) caused by hypertension.Methods and results: Male Sprague-Dawley rats were anesthetized and mechanically ventilated. Acute hypertension was induced by norepinephrine (NE) infusion and resulted in an increase in LVEDP and pulmonary artery pressure (Ppa) that were associated with a rapid fall in PaO2, and increases in lung wet/dry ratio and injury scores. Heart failure (HF) lungs showed increased nitrotyrosine content and ROS levels. L-NAME pretreatment mitigated the development of PE and reduced lung ROS concentrations to sham levels. Apocynin (Apo) pretreatment inhibited PE. Addition of tetrahydrobiopterin (BH4) to AHF rats lung lysates and pretreatment of AHF rats with folic acid (FA) prevented ROS production indicating endothelial NOS (eNOS) uncoupling.Conclusion: Pressure-dependent NOS activation leads to acute endothelial hyperpermeability and rapid PE by an increase in NO and ROS in a model of AHF. Acute increases in pulmonary vascular pressure, without NOS activation, was insufficient to cause significant PE. These results suggest a clinically relevant role of endothelial mechanotransduction in the pathogenesis of AHF and further highlights the concept of active barrier failure in AHF. Therapies targetting the prevention or reversal of endothelial hyperpermeability may be a novel therapeutic strategy in AHF.

Prolonged low-dose cyclophosphamide treatment after pulse therapy attenuates lung injury in rats with paraquat intoxication

BACKGROUND/AIMS

This study tested the hypothesis that prolonged low-dose cyclophosphamide (CTX) treatment after pulse therapy attenuate paraquat (PQ)-induced lung injury in rats.

METHODS

PQ (25 mg/kg) was administered intraperitoneally to induce PQ-intoxicated rat model. The rats were randomly divided into four groups: control group (1 mL/day saline solution for 14 days), PQ group (1 mL/day saline solution for 14 days after PQ exposure), pulse group (15 mg/kg/day CTX in 1 mL of saline solution for 2 days and subsequent 1 mL/day saline solution for 12 days), and prolonged low-dose group (15 mg/kg/day CTX in 1 mL of saline solution for 2 days and subsequent 1.5 mg/kg/day CTX in 1 mL of saline solution for 12 days). A 14-day follow-up was conducted to determine the survival rat, and lung hydroxyproline (HYP), wet-to-dry weight ratios (W/Dc) and histopathological changes were evaluated.

RESULTS

Results showed similar survival rate (55% vs. 50%, p > 0.05) between prolonged low-dose and pulse groups. Lung W/Dc (4.94 ± 0.38 vs. 5.47 ± 0.28, p < 0.01), HYP (3.34 ± 0.29 µg/mg vs. 3.65 ± 0.19 µg/mg, p < 0.001), and fibrosis score (2.69 ± 0.84 vs. 3.13 ± 0.63, p < 0.05) were lower in prolonged low-dose group than those in the pulse group.

CONCLUSION

These findings suggested prolonged low-dose CTX treatment after pulse therapy could attenuate PQ-induced lung injury in rats.

Fatal Pulmonary Edema in a Child After Jellyfish Stings in Korea

Jellyfish have been increasing at a global scale in recent years. These blooms not only have deleterious effects on marine ecosystems, they also increase the risk of jellyfish stings and accompanying envenomation. Here, we report a fatal case of pulmonary edema caused by jellyfish envenomation in a child in Korea. The patient died 4 h after envenomation despite cardiopulmonary resuscitation. Nemopilema nomurai was the suspected species of jellyfish encountered by the patient, although we are unable to confirm this. With this case report, we aim to inform on the serious issue of toxicity associated with jellyfish species that bloom mainly along Korean, east Chinese, and Japanese shores and to discuss appropriate first aid methods in case of jellyfish stings.

Pannexin-1 channels on endothelial cells mediate vascular inflammation during lung ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury (IRI), which involves inflammation, vascular permeability, and edema, remains a major challenge after lung transplantation. Pannexin-1 (Panx1) channels modulate cellular ATP release during inflammation. This study tests the hypothesis that endothelial Panx1 is a key mediator of vascular inflammation and edema after I/R and that IRI can be blocked by Panx1 antagonism. A murine hilar ligation model of IRI was used whereby left lungs underwent 1 h of ischemia and 2 h of reperfusion. Treatment of wild-type mice with Panx1 inhibitors (carbenoxolone or probenecid) significantly attenuated I/R-induced pulmonary dysfunction, edema, cytokine production, and neutrophil infiltration versus vehicle-treated mice. In addition, VE-Cad-CreERT2+/Panx1fl/fl mice (tamoxifen-inducible deletion of Panx1 in vascular endothelium) treated with tamoxifen were significantly protected from IRI (reduced dysfunction, endothelial permeability, edema, proinflammatory cytokines, and neutrophil infiltration) versus vehicle-treated mice. Furthermore, extracellular ATP levels in bronchoalveolar lavage fluid is Panx1-mediated after I/R as it was markedly attenuated by Panx1 antagonism in wild-type mice and by endothelial-specific Panx1 deficiency. Panx1 gene expression in lungs after I/R was also significantly elevated compared with sham. In vitro experiments demonstrated that TNF-α and/or hypoxia-reoxygenation induced ATP release from lung microvascular endothelial cells, which was attenuated by Panx1 inhibitors. This study is the first, to our knowledge, to demonstrate that endothelial Panx1 plays a key role in mediating vascular permeability, inflammation, edema, leukocyte infiltration, and lung dysfunction after I/R. Pharmacological antagonism of Panx1 activity may be a novel therapeutic strategy to prevent IRI and primary graft dysfunction after lung transplantation.

The triggering receptor expressed by myeloid cells-1 activates TLR4-MyD88-NF-κB-dependent signaling to aggravate ventilation-induced lung inflammation and injury in mice

The triggering receptor expressed by myeloid cells-1 (TREM-1) plays an important role in infectious and autoimmune diseases but how it contributes to ventilation-induced lung injury (VILI) and inflammation is unclear. Here, we examine the possibility that TREM-1 activates signaling dependent on Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (Myd88) and nuclear factor (NF)-κB, which leads in turn to VILI. In a mouse model of VILI, which we validated based on lung edema and histopathology as well as cytokine levels, we examine mRNA and protein levels of TREM-1, TLR4, MyD88, NF-κB and its inhibitory protein I-κB in animals subjected to ventilation at normal or high tidal volume. The extent of lung edema, injury and inflammation were higher in the high tidal volume animals, as were the expression levels of all proteins examined. Treatment with TREM-1 agonist aggravated these effects, whereas treatment with TREM-1 antagonist attenuated them. Our results suggest that aggravation of VILI by TREM-1 in mice may be associated with TLR4-MyD88-NF-κB-dependent signaling.

GSK2193874 treatment at heatstroke onset reduced cell apoptosis in heatstroke mice

Heatstroke is still a potentially fatal threat during summer heat waves, despite improved prevention and treatment. It is reported that the transient receptor potential vanilloid 4 (TRPV4) inhibitor may protect septicemia mice. Many aspects of heatstroke have been defined, from the sepsis-mimic inflammatory response to hyperthermia. Hence, TRPV4 may be a therapeutic target for heatstroke. The results in murine models of heatstroke verified that GSK2193874, as a selected TRPV4 inhibitor, was injected at heatstroke onset, and then reduced the reduction of core temperature, the death rate, wet/dry ratio of the lung, levels of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6, coagulation indicators, the degree of organ injury, and caspase-3/7 activity (P&lt;0.05). But GSK2193874 treatment before heat stress did not improve the symptoms of heatstroke mice. Therefore, TRPV4 should be involved in heatstroke-induced injury. Timely GSK2193874 administration may be useful to reduce heatstroke-induced injury. TRPV4 may be a potential new therapeutic target in fatal heatstroke.