Effects of resveratrol on the treatment of inflammatory response induced by severe burn

Triage and Evaluation of Blast-Injured Patients in Wenling Liquefied Petroleum Gas Tanker Explosion

On June 13, 2020, a liquefied petroleum gas tanker exploded in Wenling. Here, the authors describe the mass casualty emergency response to the explosion. The authors collected the medical records of 176 inpatients at 8 hospitals in Taizhou and Hangzhou. The 176 inpatients with blast injuries comprised 70 females and 106 males, with an average age of 45.48 ± 19.96 years, and more than half of the patients were farmers. They were transported to six hospitals distributed around the explosion site in Taizhou in the initial rescue period and were grouped according to their new injury severity score as having mild, moderate, severe, or extremely severe injuries. Most patients with severe and extremely severe injuries were admitted to a superior hospital for postsecondary triage. Forty-four patients experienced primary blast injuries, 137 experienced secondary blast injuries, 37 experienced tertiary blast injuries, and 40 patients experienced quaternary blast injuries. Multiple blast injuries were suffered by 62 patients. Most patients (95.45%) suffered external injuries, with the chest, extremities, and face as the main affected areas. Burns were diagnosed in 26 adults, of whom 15.38%, 19.23%, 7.70%, and 57.69% suffered mild, moderate, severe, and extremely severe cases. Sixteen burn patients suffered from burn-blast injuries. Upper limbs and the head/face/neck area, as exposed areas, were more likely to experience a burn injury. Inhalation was the main accompanying injury. Of the eight patients who died in the prehospital session, seven had burn injuries. This report on the accident and injury characteristics of an open-air LPG-related explosion will facilitate responses to subsequent catastrophes.

In Vitro and In Vivo Biocompatible and Controlled Resveratrol Release Performances of HEMA/Alginate and HEMA/Gelatin IPN Hydrogel Scaffolds

Scaffold hydrogel biomaterials designed to have advantageous biofunctional properties, which can be applied for controlled bioactive agent release, represent an important concept in biomedical tissue engineering. Our goal was to create scaffolding materials that mimic living tissue for biomedical utilization. In this study, two novel series of interpenetrating hydrogel networks (IPNs) based on 2-hydroxyethyl methacrylate/gelatin and 2-hydroxyethyl methacrylate/alginate were crosslinked using N-ethyl-N'-(3-dimethyl aminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). Characterization included examining the effects of crosslinker type and concentration on structure, morphological and mechanical properties, in vitro swelling, hydrophilicity as well as on the in vitro cell viability (fibroblast cells) and in vivo (Caenorhabditis elegans) interactions of novel biomaterials. The engineered IPN hydrogel scaffolds show an interconnected pore morphology and porosity range of 62.36 to 85.20%, favorable in vitro swelling capacity, full hydrophilicity, and Young's modulus values in the range of 1.40 to 7.50 MPa. In vitro assay on healthy human fibroblast (MRC5 cells) by MTT test and in vivo (Caenorhabditis elegans) survival assays show the advantageous biocompatible properties of novel IPN hydrogel scaffolds. Furthermore, in vitro controlled release study of the therapeutic agent resveratrol showed that these novel scaffolding systems are suitable controlled release platforms. The results revealed that the use of EDC and the combination of EDC/NHS crosslinkers can be applied to prepare and tune the properties of the IPN 2-hydroxyethyl methacrylate/alginate and 2-hydroxyethyl methacrylate/gelatin hydrogel scaffolds series, which have shown great potential for biomedical engineering applications.

Emerging Effects of Resveratrol on Wound Healing: A Comprehensive Review

Resveratrol (RSV) is a natural extract that has been extensively studied for its significant anti-inflammatory and antioxidant effects, which are closely associated with a variety of injurious diseases and even cosmetic medicine. In this review, we have researched and summarized the role of resveratrol and its different forms of action in wound healing, exploring its role and mechanisms in promoting wound healing through different modes of action such as hydrogels, fibrous scaffolds and parallel ratio medical devices with their anti-inflammatory, antioxidant, antibacterial and anti-ageing properties and functions in various cells that may play a role in wound healing. This will provide a direction for further understanding of the mechanism of action of resveratrol in wound healing for future research.

SIRT1 suppresses burn injury-induced inflammatory response through activating autophagy in RAW264.7 macrophages

The present study sought to investigate the association between silent information regulator 1 (SIRT1) and autophagy during systemic inflammatory response syndrome following burn injury. The experimental burn model in mice and macrophages were established. SIRT1 mRNA expression was quantified by quantitative real-time PCR. The protein levels of SIRT1 and the conversion of light chain 3 (LC3)-I to LC3-II were determined by western blot analysis. The formation of autophagosomes was assessed by green fluorescence protein-tagged LC3 fluorescence. The contents of inflammatory cytokines interleukin (IL)-1, IL-6, IL-10 and IL-18 were measured by ELISA. SIRT1 was highly expressed in burned tissues and RAW264.7 cells treated with serum obtained from mice with burn injuries. Moreover, SIRT1 overexpression augmented, whereas sirtinol, an inhibitor of SIRT1, attenuated burn injury-induced increasing number of autophagosomes and expression levels of LC3-II/LC3-I in RAW264.7 cells. Besides, sirtinol effectively prevented SIRT1-induced pro-inflammation during burn injury. Furthermore, autophagy inhibition by 3-methyladenine significantly attenuated SIRT1 overexpression-mediated pro-inflammatory cytokine production. SIRT1 abolished burn injury-induced inflammatory response by inducing autophagy.

Resveratrol Modulates the Inflammatory Profile of Immune Responses and Circulating Endothelial Cells' (CECs') Population During Acute Whole Body Gamma Irradiation

Wistar rats were whole body irradiated with a single dose of 2 Gy post administration with 10 or 100 mg/kg of resveratrol (RSV) intraperitoneally for 30 days. Rats’ livers were dissected and processed to analyze immune response profiles of Th1, Th2, Th9, Th17, and Th22 by flow cytometry. In addition, peripheral blood samples were collected and circulating endothelial cells (CECs) were counted as an indicator for endothelial damage. Results demonstrated that resveratrol at 100 mg/kg enhanced liver immunological response influenced by irradiation by inducing Th2 immune response that was revealed by an increase in IL-10 secretion to more than 5,000 pmol/ml post irradiation. Results also indicated that RSV, at a dose of 100 mg/kg, decreased levels of the main pro-inflammatory cytokines such as INF-γ, IL-22, IL-17A, and GM-CSF post irradiation. In addition, the same RSV was bound to upregulate the expression of IL-10 mRNA in isolated Kupffer cells (KCs) and their secretion of IL-10 post irradiation. The result demonstrated that KCs were the central source of this anti-inflammatory response mediated mainly by IL10. These results, proposed for the first time, clearly states that RSV promotes IL-10 mediated immune resolution by Kupffer cells and not by hepatocytes. This implies that KCs have a crucial role in radiotherapy. Additionally, this study showed that RSV had an anti-apoptotic effect through re-increasing the number of CECs, which is implicated in irradiation damage. Result of the current work discloses novel findings about the potential of RSV as a radio-protector agent of a natural origin and suggests novel roles of KCs as a pharmacological target during radiation exposure.

NLRC5 negatively regulates inflammatory responses in LPS-induced acute lung injury through NF-κB and p38 MAPK signal pathways

Acute lung injury is an acute inflammatory disease with high morbidity rate and high mortality rate. However, there is still no effective clinical treatment to date. Our previous studies found that NLRC5 was significantly increased in acute liver injury model induced by LPS to reduce the secretion of IL-6 and TNF-α. Nevertheless, there is no report on the role of NLRC5 in regulating the development of acute lung injury. In this study we successfully established a model of acute lung injury induced by tracheal instillation of LPS in mice, and found NLRC5 expression was apparently elevated in mouse lung tissue and primary alveolar macrophages. NLRC5 overexpression negatively regulated secretion of inflammatory cytokines in murine alveolar macrophage cells through NF-κB and p38 MAPK pathway inhibition. There is a positively feedback between NLRC5 and NF-κB or p38 MAPK pathway. This study may provide some new ideas for clinical prevention of lung injury.

Natural SIRT1 modifiers as promising therapeutic agents for improving diabetic wound healing

BACKGROUND

The occurrence of chronic wounds, account for significant suffering of diabetic people, together with increasing healthcare burden. The chronic wounds associated with diabetes do not undergo the normal healing process rather stagnate into chronic proinflammatory phase as well as declined fibroblast function and impaired cell migration.

HYPOTHESIS

SIRT1, which is the most studied isoform of the sirtuin family in mammals, has now emerged as a crucial target for improving diabetic wound healing. It is an NAD+ dependent deacetylase, originally characterized to deacetylate histone proteins leading to heterochromatin formation and gene silencing. It is now known to regulate a number of cellular processes like cell proliferation, division, senescence, apoptosis, DNA repair, and metabolism.

METHODOLOGY

The retrieval of potentially relevant studies was done by systematically searching of three databases (Google Scholar, Web of science and PubMed) in December 2019. The keywords used as search terms were related to SIRT1 and wound healing. The systematic search retrieved 649 papers that were potentially relevant and after selection procedure, 73 studies were included this review and discussed below.

RESULTS

Many SIRT1 activating compounds (SACs) were found protective and improve diabetic wound healing through regulation of inflammation, cell migration, oxidative stress response and formation of granulation tissue at the wound site.

CONCLUSIONS

However, contradictory reports describe the opposing role of SACs on the regulation of cell migration and cancer incidence. SACs are therefore subjected to intense research for understanding the mechanisms responsible for controlling cell migration and therefore possess prospective to enter the clinical arena in the foreseeable future.

Resveratrol-loaded peptide-hydrogels inhibit scar formation in wound healing through suppressing inflammation

Scar formation seriously affects the repair of damaged skin especially in adults and the excessive inflammation has been considered as the reason. The self-assembled peptide-hydrogels are ideal biomaterials for skin wound healing due to their similar nanostructure to natural extracellular matrix, hydration environment and serving as drug delivery systems. In our study, resveratrol, a polyphenol compound with anti-inflammatory effect, is loaded into peptide-hydrogel (Fmoc-FFGGRGD) to form a wound dressing (Pep/RES). Resveratrol is slowly released from the hydrogel in situ, and the release amount is controlled by the loading amount. The in vitro cell experiments demonstrate that the Pep/RES has no cytotoxicity and can inhibit the production of pro-inflammatory cytokines of macrophages. The Pep/RES hydrogels are used as wound dressings in rat skin damage model. The results suggest that the Pep/RES dressing can accelerate wound healing rate, exhibit well-organized collagen deposition, reduce inflammation and eventually prevent scar formation. The Pep/RES hydrogels supply a potential product to develop new skin wound dressings for the therapy of skin damage.

Evaluation of Neo-Osteogenesis in Eosinophilic Chronic Rhinosinusitis Using a Nasal Polyp Murine Model

Purpose

Osteitis refers to the development of new bone formation and remodeling of bone in chronic rhinosinusitis (CRS) patients; it is typically associated with eosinophilia, nasal polyps (NPs), and recalcitrant CRS. However, the roles of ossification in CRS with or without NPs remain unclear due to the lack of appropriate animal models. Thus, it is necessary to have a suitable animal model for greater advances in the understanding of CRS pathogenesis.

Methods

BALB/c mice were administered ovalbumin (OVA) and staphylococcal enterotoxin B (SEB). The numbers of osteoclasts and osteoblasts and bony changes were assessed. Micro computed tomography (micro-CT) scans were conducted to measure bone thickness. Immunofluorescence, immunohistochemistry, and quantitative polymerase chain reaction were performed to evaluate runt-related transcription factor 2 (RUNX2), osteonectin, interleukin (IL)-13, and RUNX2 downstream gene expression. Gene set enrichment analysis was performed in mucosal tissues from control and CRS patients. The effect of resveratrol was evaluated in terms of osteogenesis in a murine eosinophilic CRS NP model.

Results

The histopathologic changes showed markedly thickened bones with significant increase in osteoblast numbers in OVA/SEB-treated mice compared to the phosphate-buffered saline-treated mice. The structural changes in bone on micro-CT were consistent with the histopathological features. The expression of RUNX2 and IL-13 was increased by the administration of OVA/SEB and showed a positive correlation. RUNX2 expression mainly co-localized with osteoblasts. Bioinformatic analysis using human CRS transcriptome revealed that IL-13-induced bony changes via RUNX2. Treatment with resveratrol, a candidate drug against osteitis, diminished the expression of IL-13 and RUNX2, and the number of osteoblasts in OVA/SEB-treated mice.

Conclusions

In the present study, we found the histopathological and radiographic evidence of osteogenesis using a previously established murine eosinophilic CRS NP model. This animal model could provide new insights into the pathophysiology of neo-osteogenesis and provide a basis for developing new therapeutics.

Protective effects of resveratrol improve cardiovascular function in rats with diabetes

Resveratrol is a flavonoid with a stilbene structure that is able to suppress acute pulmonary thromboembolism-induced pulmonary artery hypertension. Furthermore, it possesses anti-cancer and antioxidant properties, is able to regulate blood lipids and increase life expectancy. In the present study, it was evaluated whether the protective effect of resveratrol was able to improve cardiovascular function in rats with diabetes. The effects of resveratrol on blood glucose, body weight, heart/body weight ratio, plasma triglyceride levels, heart rate, aspartate transaminase (AST)/alanine transaminase (ALT) ratio and total plasma insulin were evaluated. Levels of inflammation and oxidative stress were also evaluated using ELISA kits, and the expressions of endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF) and phosphorylated (p)-p38 protein were evaluated via western blot analysis. The results demonstrated that administration of resveratrol in rats with diabetes-related myocardial infarction (DRMI) significantly reduced blood glucose, body weight, plasma triglyceride levels, heart rate and AST/ALT ratio (all P<0.01) and significantly increased total plasma insulin (P<0.01). Furthermore, resveratrol significantly reduced levels of inflammation factors (P<0.01) and malondialdehyde, a marker for oxidative stress, in rats with DRMI (P<0.01). Resveratrol significantly increased the expression of eNOS (P<0.01) and suppressed the expression of VEGF and p-p38 (both P<0.01) in rats with DRMI. These results suggest that treatment with resveratrol is able to improve cardiovascular function via inhibition of eNOS and VEGF, and suppression of p38 phosphorylation in rats with DRMI.

Deep Sequencing Transcriptome Analysis of Murine Wound Healing: Effects of a Multicomponent, Multitarget Natural Product Therapy-Tr14

Wound healing involves an orchestrated response that engages multiple processes, such as hemostasis, cellular migration, extracellular matrix synthesis, and in particular, inflammation. Using a murine model of cutaneous wound repair, the transcriptome was mapped from 12 h to 8 days post-injury, and in response to a multicomponent, multi-target natural product, Tr14. Using single-molecule RNA sequencing (RNA-seq), there were clear temporal changes in known transcripts related to wound healing pathways, and additional novel transcripts of both coding and non-coding genes. Tr14 treatment modulated >100 transcripts related to key wound repair pathways, such as response to wounding, wound contraction, and cytokine response. The results provide the most precise and comprehensive characterization to date of the transcriptome's response to skin damage, repair, and multicomponent natural product therapy. By understanding the wound repair process, and the effects of natural products, it should be possible to intervene more effectively in diseases involving aberrant repair.

Impairment of tear film and the ocular surface in patients with facial burns

AIM

The aim of this study is to investigate the factors affecting tear film and ocular surface in patients with facial burns.

METHODS

A total of 273 patients with facial burns, treated at Hallym University Hangang Sacred Heart Hospital from November 2012 to July 2015, were included. Tear break-up time (TBUT), Schirmer's tear secretion test, fluorescein staining score (FSS), ocular surface disease index (OSDI), and visual analogue pain score (VAS) were compared according to burned surface area, burn site, burn cause, time since burn injury, or lid abnormality.

RESULTS

Mean age was 48.66±14.46years (range: 18-85). Tear film stability was not different according to burn area, burn site, or burn cause. Facial burn patients with lid abnormalities had shorter TBUT and higher OSDI scores compared to no lid abnormality (p<0.001 and 0.015, independent t-test). There was no difference in TBUT and tear secretion according to area, site, or cause of burn. FSS was different according to the area of burn (p=0.007, ANOVA). OSDI and VAS was higher in the patients with an electrical burn compared to thermal burn (p=0.003 and 0.024, ANOVA).

CONCLUSIONS

Facial burn patients with lid abnormalities had tear film instability and ocular discomforts. Aggressive treatment may be of benefit in facial burn patients with lid involvement. Electrical burn caused more severe pain compared to thermal burn. Attention should be paid to pain control in patients with electrical burns.

Resveratrol improves mitochondrial function in the remnant kidney from 5/6 nephrectomized rats

Mitochondrial dysfunction is involved in the pathogenesis of chronic kidney disease (CKD). Resveratrol has been demonstrated to be beneficial for the recovery of kidney diseases. In this study, the 5/6 nephrectomized rat was used as a CKD model and the TGF-β1-exposed mouse mesangial cells were used as an in vitro model. Pathological examination showed that resveratrol treatment attenuated glomerular injury in the remnant kidney of 5/6 nephrectomized rat. Additionally, resveratrol improved mitochondrial function in vivo and in vitro, as evidenced by increasing mitochondrial membrane potential, increasing ATP, decreasing reactive oxygen species production and enhancing activities of complex I and III. Furthermore, the dysregulated expressions of electron transport chain proteins and fission/fusion proteins in the kidney of 5/6 nephrectomize rats and TGF-β1-exposed mesangial cells were restored by resveratrol. Finally, upregulated sirt1 and PGC-1α deacetylation were found after treatment with resveratrol in vivo and in vitro, which may contribute to the mitochondrial protective effects of resveratrol. The results demonstrate that resveratrol protects the mitochondria of kidney in 5/6 nephrectomized rats and TGF-β1 induced mesangial cells. The study provides new insights into the renoprotective mechanisms of resveratrol.

Resveratrol inhibits lung cancer growth by suppressing M2-like polarization of tumor associated macrophages

In cancer, tumor associated macrophages (TAMs) play an important role in the cancer progression, evasion of immunity and dissemination of cancer cells. Inhibition of the activation or the M2 polarization of TAMs is an effective therapy for cancer. In the present study, we investigated the ability of resveratrol (RES) to inhibit lung cancer growth using in vitro and in vivo studies, and examined the underlying mechanisms. We demonstrated that M2 polarization of human monocyte derived macrophage (HMDMs) induced by the lung cancer cells conditioned medium was inhibited by RES. Additionally, RES exhibited inhibitory function in lung cancer cells co-cultured with human macrophages. The activity of signal transducer and activator of transcription 3 (STAT3) was significantly decreased by RES. Moreover, in a mouse lung cancer xenograft model, RES significantly inhibited the tumor growth, which was associated with inhibition of cell proliferation and decreased expression of p-STAT3 in tumor tissues. Further, RES inhibits F4/80 positive expressing cells and M2 polarization in the tumors. These results suggest that RES can effectively inhibit lung cancer progression by suppressing the protumor activation of TAMs.

The protective effects of bone marrow-derived mesenchymal stem cell (BMSC) on LPS-induced acute lung injury via TLR3-mediated IFNs, MAPK and NF-κB signaling pathways

The study attempted to clarify the protective role of bone marrow-derived mesenchymal stem cell (BMSC) transplantation on LPS-induced acute lung injury (ALI) of rats. BMSC were obtained from bone marrow of rat, cultured and proliferated in vitro. Rats of ALI were established through lipopolysaccharide (LPS) administration. Male rats were allocated to control group, ALI group and BMSC, transplantation group. Rats were sacrificed after BMSC injection after 12h, 24h and 48h. Here we investigated the role of BMSC in LPS-induced alveolar macrophages to further demonstrate the mechanism of BMSC to lung injury. TLR3, a member of Toll-like receptor family, has been found in macrophages and the cell surface. In our study, first BMSC successfully reversed LPS-induced lung injury by hematoxylin-eosin (H&E) staining, ameliorated apoptosis via TUNEL and flow cytometer analysis, as well as improved cell structure. And then, western blot, quantitative real-time PCR, immunohistochemistry and immunofluorescence analysis were used to confirm that TLR3 was significantly down-regulated for BMSC treatment. Subsequently, TRIF and RIP1, down-streaming signals of TLR3, were inhibited greatly, leading to TRAF3, MAPK as well as NF-κB inactivity. Our results indicated that BMSC transplantation group displayed inhibitory effects on interferon (IFNs) levels via TLR3 in LPS-induced ALI and preventive effects on inflammation response via TLR3-regualted MAPK and NF-κB signaling pathway in LPS-induced lung injury. The present study indicated that BMSC could display protective effects on LPS-induced ALI and provide an experimental basis for clinical therapy.

Resveratrol suppresses myofibroblast activity of human buccal mucosal fibroblasts through the epigenetic inhibition of ZEB1 expression

Oral submucous fibrosis (OSF) is a precancerous condition of the oral mucosa without specific therapeutic drugs. We previously demonstrated that the zinc finger E-box binding homeobox 1 (ZEB1) plays a pathogenic role in the induction of the myofibroblast activity of buccal mucosal fibroblasts (BMFs) and contributes to the pathogenesis of OSF. Resveratrol is a natural polyphenolic flavonoid with anti-fibrosis activity in various tissues and has the capability to inhibit ZEB1 in oral cancer cells. We examined the effect of resveratrol on the myofibroblast activity of human primary fibrotic BMFs (fBMFs) derived from OSF tissues. With the collagen contraction assay, resveratrol displayed anti-myofibroblast activity in three fBMF lines. Resveratrol also inhibited the expression of fibrogenic genes at the mRNA and protein levels in a dose- and time-dependent manner. The downregulation of ZEB1 in fBMFs by resveratrol was mediated by epigenetic mechanisms, such as the upregulated expression of miR-200c and the enhancer of zeste homolog 2 (EZH2), as well as the trimethylated lysine 27 of histone H3 (H3K27me3). Resveratrol also increased the binding of H3K27me3 to the ZEB1 promoter. The knockdown of EZH2 in fBMFs caused the upregulation of ZEB1 and suppressed the inhibitory effect of resveratrol. Furthermore, the reversed expression pattern between EZH2 and ZEB1 was observed in 6/8 OSF tissues with twofold upregulation of ZEB1 expression compared with the adjacent normal mucosa. In conclusion, our data suggest that resveratrol epigenetically inhibits ZEB1 expression to suppress the myofibroblast activity of fBMFs and may serve as a dietary supplement for OSF patients.

ROS-Mediated NLRP3 Inflammasome Activity Is Essential for Burn-Induced Acute Lung Injury

The NLRP3 inflammasome is necessary for initiating acute sterile inflammation. However, its role in the pathogenesis of burn-induced acute lung injury (ALI) is unknown. This study aimed to determine the role of the NLRP3 inflammasome and the signaling pathways involved in burn-induced ALI. We observed that the rat lungs exhibited enhanced inflammasome activity after burn, as evidenced by increased levels of NLRP3 expression and Caspase-1 activity and augmented inflammatory cytokines. Inhibition of NLRP3 inflammasome by BAY11-7082 attenuated burn-induced ALI, as demonstrated by the concomitant remission of histopathologic changes and the reduction of myeloperoxidase (MPO) activity, inflammatory cytokines in rat lung tissue, and protein concentrations in the bronchoalveolar lavage fluid (BALF). In the in vitro experiments, we used AMs (alveolar macrophages) challenged with burn serum to mimic the postburn microenvironment and noted that the serum significantly upregulated NLRP3 inflammasome signaling and reactive oxygen species (ROS) production. The use of ROS scavenger N-acetylcysteine (NAC) partially reversed NLRP3 inflammasome activity in cells exposed to burn serum. These results indicate that the NLRP3 inflammasome plays an essential role in burn-induced ALI and that burn-induced NLRP3 inflammasome activity is a partly ROS-dependent process. Targeting this axis may represent a promising therapeutic strategy for the treatment of burn-induced ALI.

ROS-Mediated NLRP3 Inflammasome Activity Is Essential for Burn-Induced Acute Lung Injury

The NLRP3 inflammasome is necessary for initiating acute sterile inflammation. However, its role in the pathogenesis of burn-induced acute lung injury (ALI) is unknown. This study aimed to determine the role of the NLRP3 inflammasome and the signaling pathways involved in burn-induced ALI. We observed that the rat lungs exhibited enhanced inflammasome activity after burn, as evidenced by increased levels of NLRP3 expression and Caspase-1 activity and augmented inflammatory cytokines. Inhibition of NLRP3 inflammasome by BAY11-7082 attenuated burn-induced ALI, as demonstrated by the concomitant remission of histopathologic changes and the reduction of myeloperoxidase (MPO) activity, inflammatory cytokines in rat lung tissue, and protein concentrations in the bronchoalveolar lavage fluid (BALF). In the in vitro experiments, we used AMs (alveolar macrophages) challenged with burn serum to mimic the postburn microenvironment and noted that the serum significantly upregulated NLRP3 inflammasome signaling and reactive oxygen species (ROS) production. The use of ROS scavenger N-acetylcysteine (NAC) partially reversed NLRP3 inflammasome activity in cells exposed to burn serum. These results indicate that the NLRP3 inflammasome plays an essential role in burn-induced ALI and that burn-induced NLRP3 inflammasome activity is a partly ROS-dependent process. Targeting this axis may represent a promising therapeutic strategy for the treatment of burn-induced ALI.

ROS-Mediated NLRP3 Inflammasome Activity Is Essential for Burn-Induced Acute Lung Injury

The NLRP3 inflammasome is necessary for initiating acute sterile inflammation. However, its role in the pathogenesis of burn-induced acute lung injury (ALI) is unknown. This study aimed to determine the role of the NLRP3 inflammasome and the signaling pathways involved in burn-induced ALI. We observed that the rat lungs exhibited enhanced inflammasome activity after burn, as evidenced by increased levels of NLRP3 expression and Caspase-1 activity and augmented inflammatory cytokines. Inhibition of NLRP3 inflammasome by BAY11-7082 attenuated burn-induced ALI, as demonstrated by the concomitant remission of histopathologic changes and the reduction of myeloperoxidase (MPO) activity, inflammatory cytokines in rat lung tissue, and protein concentrations in the bronchoalveolar lavage fluid (BALF). In the in vitro experiments, we used AMs (alveolar macrophages) challenged with burn serum to mimic the postburn microenvironment and noted that the serum significantly upregulated NLRP3 inflammasome signaling and reactive oxygen species (ROS) production. The use of ROS scavenger N-acetylcysteine (NAC) partially reversed NLRP3 inflammasome activity in cells exposed to burn serum. These results indicate that the NLRP3 inflammasome plays an essential role in burn-induced ALI and that burn-induced NLRP3 inflammasome activity is a partly ROS-dependent process. Targeting this axis may represent a promising therapeutic strategy for the treatment of burn-induced ALI.