Inhibitor of nuclear factor-κB, SN50, attenuates lipopolysaccharide-induced lung injury in an isolated and perfused rat lung model

α7nAChR Activation Combined with Endothelial Progenitor Cell Transplantation Attenuates Lung Injury in Diabetic Rats with Sepsis through the NF-κB Pathway

Chronic diabetes mellitus compromises the vascular system, which causes organ injury, including in the lung. Due to the strong compensatory ability of the lung, patients always exhibit subclinical symptoms. Once sepsis occurs, the degree of lung injury is more severe under hyperglycemic conditions. The α7 nicotinic acetylcholine receptor (α7nAChR) plays an important role in regulating inflammation and metabolism and can improve endothelial progenitor cell (EPC) functions. In the present study, lung injury caused by sepsis was compared between diabetic rats and normal rats. We also examined whether α7nAChR activation combined with EPC transplantation could ameliorate lung injury in diabetic sepsis rats. A type 2 diabetic model was induced in rats via a high-fat diet and streptozotocin. Then, a rat model of septic lung injury was established by intraperitoneal injection combined with endotracheal instillation of LPS. The oxygenation indices, wet-to-dry ratios, and histopathological scores of the lungs were tested after PNU282987 treatment and EPC transplantation. IL-6, IL-8, TNF-α, and IL-10 levels were measured. Caspase-3, Bax, Bcl-2, and phosphorylated NF-κB (p-NF-κB) levels were determined by blotting. Sepsis causes obvious lung injury, which is exacerbated by diabetic conditions. α7nAChR activation and endothelial progenitor cell transplantation reduced lung injury in diabetic sepsis rats, alleviating inflammation and decreasing apoptosis. This treatment was more effective when PNU282987 and endothelial progenitor cells were administered together. p-NF-κB levels decreased following treatment with PNU282987 and EPCs. In conclusion, α7nAChR activation combined with EPC transplantation can alleviate lung injury in diabetic sepsis rats through the NF-κB signaling pathway.

Long Noncoding RNA Metastasis-Associated Lung Adenocarcinoma Transcript 1 Promotes HIV-1 Replication through Modulating microRNAs in Macrophages

Macrophages can serve as a reservoir for human immunodeficiency-1 (HIV-1) virus in host cells, constituting a barrier to eradication, even in patients who are receiving antiretroviral therapy. Although many noncoding RNAs have been characterized as regulators in HIV-1/AIDS-induced immune response and pathogenesis, only a few long noncoding RNAs (lncRNAs) have demonstrated a close association with HIV-1 replication, and the molecular mechanisms remain unknown. In this study, we investigated how lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), related microRNAs, and key inflammatory genes alter HIV-1 replication in macrophages. Our data show that HIV-1 infection modulates the expression of miR-155 and miR-150-5p in a time-dependent manner, which is regulated by MALAT1. MALAT1 induced suppressor of cytokine signaling 1 (SOCS1) expression by sponging miR-150-5p in HIV-1-infected macrophages and stimulated inflammatory mediators triggering receptor expressed on myeloid cells/cold inducible RNA binding protein (TREM 1/CIRP) ligand/receptor. The RNA immunoprecipitation (RIP) assay validated the direct interaction within the MALAT1/miR-150-5p/SOCS1 axis. HIV-1 infection-mediated upregulation of MALAT1, SOCS1, and HIV-1 Gag was attenuated by SN50 (an NF-кB p50 inhibitor). MALAT1 antisense oligonucleotides (ASOs) suppressed HIV-1 p24 production and HIV-1 Gag gene expression and decreased expression of miR-155 and SOCS1, as well as the production of proinflammatory cytokines by HIV-1-infected macrophages. In conclusion, HIV-1 infection induces MALAT1, which attenuates miR-150-5p expression and increases SOCS1 expression, promoting HIV-1 replication and reactivation. These data provide new insights into how MALAT1 alters the macrophage microenvironment and subsequently promotes viral replication and suggest a potential role for targeting MALAT1 as a therapeutic approach to eliminate HIV-1 reservoirs. IMPORTANCE Viral reservoirs constitute an obstacle to curing HIV-1 diseases, despite antiretroviral therapy. Macrophages serve as viral reservoirs in HIV infection by promoting long-term replication and latency. Recent studies have shown that lncRNAs can modulate virus-host interactions, but the underlying mechanisms are not fully understood. In this study, we demonstrate how lncRNA MALAT1 contributes to HIV-1 replication through modulation of the miR-150/SOCS1 axis in human macrophages. Our findings have the potential to identify new therapies for eliminating HIV-1 reservoirs in immune cells.

Dual delivery of an NF-κB inhibitor and IL-10 through supramolecular hydrogels polarizes macrophages and promotes cardiac repair after myocardial infarction

The use of anti-inflammatory strategies has the potential to be a definitive treatment for ventricular remodeling post myocardial infarction (MI). The regulation of macrophage phenotypes by anti-inflammatory agents contributes to the alleviation of myocardial fibrosis. However, their poor retention rates severely affect treatment efficacy. Here, we propose a supramolecular compound, NapFFY, to co-assemble with IL-10 and SN50 as a novel anti-inflammatory SN50/IL-10/NapFFY hydrogel with cardioprotective properties. Results from the in vitro and in vivo experiments in murine cell line and rats, respectively, demonstrated that the SN50/IL-10/NapFFY hydrogel exhibits an ideal and sustained release of IL-10 and SN50. Intramyocardial injection of the SN50/IL-10/NapFFY hydrogel in a rat model of MI significantly inhibited the expression of proinflammatory cytokines. It promoted the polarization of M2 macrophages, which reduced cardiomyocyte apoptosis and improved vascularization at the border zones. Specifically, the SN50/IL-10/NapFFY hydrogel significantly improved heart function and ameliorated ventricular remodeling 28 days post MI. We envision that the SN50/IL-10/NapFFY hydrogel could serve as a new anti-inflammatory agent for the clinical treatment of MI in future studies. STATEMENT OF SIGNIFICANCE: Anti-inflammation is an ideal strategy for the treatment of ventricular remodeling post myocardial infarction (MI). SN50 and IL-10 have been shown to have diverse roles in antiinflammatory process, respectively. However, direct intravenous administration or intramyocardial injection of SN50 or IL-10 is not a viable option given its poor half-life in vivo. This study aimed to evaluate the synergistic cardioprotective effects of a supramolecular hydrogel loaded with an NF-κB inhibitor (SN50) and IL-10. Animal experiments showed that the SN50/IL-10/NapFFY hydrogels ameliorated the inflammatory microenvironment, and improved cardiac function to the infarct area in a rat model of MI. We anticipate that SN50/IL10NapFFY hydrogel could be used clinically to treat MI in the near future.

PTOV1 promotes cisplatin-induced chemotherapy resistance by activating the nuclear factor kappa B pathway in ovarian cancer

Chemotherapy resistance is a bottleneck for ovarian cancer treatment; therefore, revealing its regulatory mechanism is critical. In the present study, we found that prostate tumor overexpressed-1 (PTOV1) was upregulated significantly in ovarian cancer cells and tissues. Patients with high PTOV1 levels had a poor outcome. In addition, PTOV1 overexpression increased CDDP (cisplatin) resistance, while PTOV1 knockdown inhibited CDDP resistance, as determined using cell viability assays, apoptosis assays, and an animal model. Mechanistic analysis showed that PTOV1 increased nuclear factor kappa B (NF-κB) pathway activity, reflected by increased nuclear translocation of its p65 subunit and the phosphorylation of inhibitor of nuclear factor kappa-B kinase subunits alpha and beta, which are markers of NF-κB pathway activation. Inhibition of the NF-κB pathway in PTOV1-overexpressing ovarian cancer cells increased CDDP-induced apoptosis, suggesting that PTOV1 promoted chemotherapy resistance by activating the NF-κB pathway. In summary, we identified PTOV1 as a prognostic factor for patients with ovarian cancer. PTOV1 might be a target for inhibition of chemotherapy resistance.

[Effect of directive differentiation of microglia by SN50 on hypoxia-caused neurons injury in mice]

Objective

To explore the effect and mechanism of directive differentiation of microglia by SN50 on hypoxia-caused neurons injury in mice.

Methods

The microglia were isolated and purified from brain tissue of new-born BALB/c mice through differential velocity adherent and vibration technique. The quantity of the microglia was identified by immunofluorescence staining of inducible nitric oxide synthetase (iNOS) and ionized calcium binding adapter molecule 1 (Iba1) and real-time fluorescence quantitative PCR (qRT-PCR) for special expression genes [iNOS, CD32, and interlenkin 10 (IL-10)]. Then the microglia were cultured with SN50, and the expressions of nuclear factor κB (NF-κB), differentiation-related genes (iNOS, CD11b, IL-10, and CD206), and apoptosis were detected by Western blot, qRT-PCR, and flow cytometry, respectively. The hypoxia model of neuron was established, and the cell apoptosis was evaluated by MTT after 0, 2, 6, 12, 24, and 48 hours of anoxic treatment. The apoptosis related markers (Bcl-2 and Caspase-3) were measured by Western blot and flow cytometry. In addition, the neurons after anoxic treatment were co-cultured with SN50 treated microglia (experimental group) and normal microglia (control group) for 24 hours. And the cell viability and apoptosis related markers (Bcl-2 and Caspase-3) were also measured.

Results

Immunofluorescence staining and qRT-PCR analysis showed that the cells expressed the specific proteins and genes of microglia. Compared with the normal microglia, the relative expressions of NF-κB protein and iNOS and CD11b mRNAs in the microglia treated with SN50 significantly decreased ( P<0.05), the relative expressions of IL-10 and CD206 mRNAs significantly increased ( P<0.05), and the cell apoptosis rate had no significant change ( P>0.05). Compared with the normal neurons, the cell viability, the relative expressions of Bcl-2 and Caspase-3 proteins after anoxic treatment significantly decreased ( P<0.05), while the relative expressions of cleaved-Caspase-3 protein and cell apoptosis rate of neurons significantly increased ( P<0.05). In the co-culture system, the cell viability, the relative expressions of Bcl-2 and Caspase-3 proteins were significantly higher in experimental group than those in control group ( P<0.05), while the relative expressions of cleaved-Caspase-3 protein and cell apoptosis rate were significantly lower in experimental group than those in control group ( P<0.05).

Conclusion

SN50 can induce the microglia differentiation into M2 type through NF-κB pathway. The SN50-induced microglia can protect neurons from hypoxic injury.

SN50 attenuates alveolar hypercoagulation and fibrinolysis inhibition in acute respiratory distress syndrome mice through inhibiting NF-κB p65 translocation

Background

It has been confirmed that NF-κB p65 signaling pathway is involved in the regulation of alveolar hypercoagulation and fibrinolysis inhibition in acute respiratory distress syndrome (ARDS). Whether SN50, a NF-κB cell permeable inhibitor, could attenuate alveolar hypercoagulation and fibrinolysis inhibition in ARDS remains to be elucidated.

Purpose

We explored the efficacy and potential mechanism of SN50 on alveolar hypercoagulation and fibrinolysis inhibition in ARDS in mice.

Materials and methods

Mouse ARDS was made by 50 μl of lipopolysaccharide (LPS) (4 mg/ml) inhalation. Male BALB/c mice were intraperitoneally injected with different does of SN50 1 h before LPS inhalation. Lung tissues were collected for hematoxylin-eosin (HE) staining, wet/dry ratio. Pulmonary expressions of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1), collagen III, as well as phosphorylated p65 (p-p65), p65 in nucleus (p’-p65), IκBα and IKKα/β were measured. Bronchoalveolar lavage fluid (BALF) was gathered to test the concentrations of TF, PAI-1, activated protein C (APC) and thrombinantithrombin complex (TAT). DNA binding activity of NF-κB p65 was also determined.

Results

After LPS stimulation, pulmonary edema and exudation and alveolar collapse occured. LPS also stimulated higher expressions of TF and PAI-1 in lung tissues, and higher secretions of TF, PAI-1, TAT and low level of APC in BALF. Pulmonary collagen III expression was obviously enhanced after LPS inhalation. At same time, NF-κB signaling pathway was activated with LPS injury, shown by higher expressions of p-p65, p’-p65, p-IKKα/β, p-Iκα in pulmonary tissue and higher level p65 DNA binding activity. SN50 dose-dependently inhibited TF, PAI-1 and collagen IIIexpressions, and decreased TF, PAI-1, TAT but increased APC in BALF. SN50 treatment attenuated pulmonary edema, exudation and reduced lung tissue damage as well. SN50 application significantly reduced p’-p65 expression and weakened p65 DNA binding activity, but expressions of p-p65, p-IKKα/β, p-Iκα in cytoplasm of pulmonary tissue were not affected.

Conclusions

SN 50 attenuates alveolar hypercoagulation and fibrinolysis inhibition in ARDS via inhibition of NF-κB p65 translocation. Our data demonstrates that NF-κB p65 pathway is a viable new therapeutic target for ARDS treatment.

SN50, a Cell-Permeable Inhibitor of Nuclear Factor-κB, Attenuates Ventilator-Induced Lung Injury in an Isolated and Perfused Rat Lung Model

High tidal volume (VT) ventilation causes the release of various mediators and results in ventilator-induced lung injury (VILI). SN50, a cell-permeable nuclear factor-κB (NF-κB) inhibitory peptide, attenuates inflammation and acute respiratory distress syndrome. However, the mechanisms associated with the effects of SN50 in VILI have not been fully elucidated. We investigated the cellular and molecular mechanisms for the effects of SN50 treatment in VILI. An isolated and perfused rat lung model was exposed to low (5 mL/kg) or high (15 mL/kg) VT ventilation for 6 h. SN50 was administered in the perfusate at the onset of the high-stretch mechanical ventilation. The hemodynamics, lung histological changes, inflammatory responses, and activation of apoptotic pathways were evaluated. VILI was demonstrated by increased pulmonary vascular permeability and lung weight gain, as well as by increased levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, myeloperoxidase (MPO), hydrogen peroxide, and macrophage inflammatory protein-2 in the bronchoalveolar lavage fluid. The lung tissue expression of TNF-α, IL-1β, mitogen-activated protein kinases (MAPKs), caspase-3, and phosphorylation of serine/threonine-specific protein kinase (p-AKT) was greater in the high VT group than in the low VT group. Upregulation and activation of NF-κB was associated with increased lung injury in VILI. SN50 attenuated the inflammatory responses, including the expression of IL-1β, TNF-α, MPO, MAPKs, and NF-κB. In addition, the downregulation of apoptosis was evaluated using caspase-3 and p-AKT expression. Furthermore, SN50 mitigated the increases in the lung weights, pulmonary vascular permeability, and lung injury. In conclusion, VILI is associated with inflammatory responses and activation of NF-κB. SN50 inhibits the activation of NF-κB and attenuates VILI.

Parkin regulates lipopolysaccharide-induced proinflammatory responses in acute lung injury

The acute respiratory distress syndrome (ARDS) is a serious condition resulting from direct or indirect lung injury that is associated with high mortality and morbidity. A key biological event in the pathogenesis of the acute lung injury (ALI) that causes acute respiratory distress syndrome is activation of the lung endothelium cells (ECs), which is triggered by a variety of inflammatory insults leading to barrier disruption and excessive accumulation of neutrophils. Recently, we demonstrated that imatinib protects against lipopolysaccharide (LPS)-induced EC activation by inhibiting c-Abl kinase. In the present study, we explored the role of parkin, a novel c-Abl substrate, in ALI. Parkin is an E3 ubiquitin ligase originally characterized in the pathogenesis of Parkinson disease; however, its potential role in acute inflammatory processes and lung EC function remains largely unknown. Using parkin deficient (PARK2-/-) mice, we now demonstrate that parkin mediates LPS-induced ALI. After LPS, PARK2-/- mice have reduced total protein and cell levels in bronchoalveolar lavage (BAL) compared to wild type. Moreover, in LPS-treated PARK2-/- lungs, the sequestration and activation of neutrophils and release of inflammatory cytokines (interleukin 6 [IL-6], tumor necrosis factor alpha [TNF-α]) are significantly reduced. The BAL levels of soluble VCAM-1 and ICAM-1 are also decreased in LPS-treated PARK2-/- mice compared to wild type. In cultured human lung endothelial cells, downregulation of parkin by small interfering RNA decreases LPS-induced VCAM-1 expression, IL-8 and IL-6 secretion, and NF-kB phosphorylation. These results suggest a previously unidentified role of parkin in mediating endotoxin-induced endothelial proinflammatory signaling and indicate that it may play a critical role in acute inflammation.

LincRNA-Gm4419 knockdown ameliorates NF-κB/NLRP3 inflammasome-mediated inflammation in diabetic nephropathy

Diabetic nephropathy (DN) as the primary cause of end-stage kidney disease is a common complication of diabetes. Recent researches have shown the activation of nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) and NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome are associated with inflammation in the progression of DN, but the exact mechanism is unclear. Long noncoding RNAs (lncRNAs) have roles in the development of many diseases including DN. However, the relationship between lncRNAs and inflammation in DN remains largely unknown. Our previous study has revealed that 14 lncRNAs are abnormally expressed in DN by RNA sequencing and real-time quantitative PCR (qRT-PCR) in the renal tissues of db/db DN mice. In this study, these lncRNAs were verified their expressions by qRT-PCR in mesangial cells (MCs) cultured under high- and low-glucose conditions. Twelve lncRNAs displayed the same expressional tendencies in both renal tissues and MCs. In particular, long intergenic noncoding RNA (lincRNA)-Gm4419 was the only one associating with NF-κB among these 12 lncRNAs by bioinformatics methods. Moreover, Gm4419 knockdown could obviously inhibit the expressions of pro-inflammatory cytokines and renal fibrosis biomarkers, and reduce cell proliferation in MCs under high-glucose condition, whereas overexpression of Gm4419 could increase the inflammation, fibrosis and cell proliferation in MCs under low-glucose condition. Interestingly, our results showed that Gm4419 could activate the NF-κB pathway by directly interacting with p50, the subunit of NF-κB. In addition, we found that p50 could interact with NLRP3 inflammasome in MCs. In conclusion, our findings suggest lincRNA-Gm4419 may participate in the inflammation, fibrosis and proliferation in MCs under high-glucose condition through NF-κB/NLRP3 inflammasome signaling pathway, and may provide new insights into the regulation of Gm4419 during the progression of DN.

Functionalized cell nucleus-penetrating peptide combined with doxorubicin for synergistic treatment of glioma

Clinical application of cell-penetrating peptides (CPPs) in cancer therapy is greatly restricted due to lack of tissue selectivity and tumor-targeting ability. CB5005, a rationally designed CPP that targets and inhibits intracellular NF-κB activation, is constituted by a unique membrane-permeable sequence (CB5005M) cascading to a NF-κB nuclear localization sequence (CB5005N). In vitro cellular evaluation confirmed that CB5005 was effectively taken up by brain capillary endothelial cell bEnd.3 and glioma cells U87. The intracellular localization analysis further demonstrated that CB5005 could not only penetrate into the cells but also enter into their nuclei. More interestingly, CB5005 permeated deeply into the tumor spheroids of U87 cell. In vivo imaging illustrated that the fluorescence-labeled CB5005 distributed itself into the brain and accumulated at the tumor site after intravenous injection. Given the important role of over expressed NF-κB in tumor growth and development, we further investigated CB5005 for its potential in treatment of glioma. When combined administration in vitro with doxorubicin (DOX), CB5005 exhibited a synergistic effect in killing U87 cells. In a nude mice xenograft model, CB5005 inhibited the growth of tumor when applied alone, and displayed a synergistic anti-tumor effect with DOX. In conclusion, CB5005 functioned simultaneously as a cell penetrating peptide and a tumor growth inhibitor, therefore can work as a potential synergist for chemotherapy of human tumor.

STATEMENT OF SIGNIFICANCE

Clinical application of cell-penetrating peptides in cancer therapy is restricted due to lack of tissue selectivity and tumor-targeting ability. In this manuscript, we reported a rationally designed peptide, named CB5005, which had an attractive capability of translocation into the cell nucleus and blocking nuclear translocation of endogenous NF-κB protein. CB5005 had unique affinity with brain and glioma, and could rapidly accumulate in these tissues after intravenous injection. Furthermore, CB5005 showed a synergistic effect on inhibiting gliomas when administrated with doxorubicin. This is the first literature report on this multi-functionalized peptide, which can work as a potential synergist for chemotherapy of tumor. This work should be of general interest to scientists in the fields of biomaterials, biology, pharmacy, and oncology.

Resolution of Inflammation: What Controls Its Onset?

An effective resolution program may be able to prevent the progression from non-resolving acute inflammation to persistent chronic inflammation. It has now become evident that coordinated resolution programs initiate shortly after inflammatory responses begin. In this context, several mechanisms provide the fine-tuning of inflammation and create a favorable environment for the resolution phase to take place and for homeostasis to return. In this review, we focus on the events required for an effective transition from the proinflammatory phase to the onset and establishment of resolution. We suggest that several mediators that promote the inflammatory phase of inflammation can simultaneously initiate a program for active resolution. Indeed, several events enact a decrease in the local chemokine concentration, a reduction which is essential to inhibit further infiltration of neutrophils into the tissue. Interestingly, although neutrophils are cells that characteristically participate in the active phase of inflammation, they also contribute to the onset of resolution. Further understanding of the molecular mechanisms that initiate resolution may be instrumental to develop pro-resolution strategies to treat complex chronic inflammatory diseases, in humans. The efforts to develop strategies based on resolution of inflammation have shaped a new area of pharmacology referred to as "resolution pharmacology."

Resolution of Inflammation: What Controls Its Onset?

An effective resolution program may be able to prevent the progression from non-resolving acute inflammation to persistent chronic inflammation. It has now become evident that coordinated resolution programs initiate shortly after inflammatory responses begin. In this context, several mechanisms provide the fine-tuning of inflammation and create a favorable environment for the resolution phase to take place and for homeostasis to return. In this review, we focus on the events required for an effective transition from the proinflammatory phase to the onset and establishment of resolution. We suggest that several mediators that promote the inflammatory phase of inflammation can simultaneously initiate a program for active resolution. Indeed, several events enact a decrease in the local chemokine concentration, a reduction which is essential to inhibit further infiltration of neutrophils into the tissue. Interestingly, although neutrophils are cells that characteristically participate in the active phase of inflammation, they also contribute to the onset of resolution. Further understanding of the molecular mechanisms that initiate resolution may be instrumental to develop pro-resolution strategies to treat complex chronic inflammatory diseases, in humans. The efforts to develop strategies based on resolution of inflammation have shaped a new area of pharmacology referred to as “resolution pharmacology.”

Characteristics of microRNAs and their potential relevance for the diagnosis and therapy of the acute respiratory distress syndrome: from bench to bedside

Acute respiratory distress syndrome (ARDS) is a complex disease associated with high morbidity and mortality. Biomarkers and specific pharmacologic treatment of the syndrome are lacking. MicroRNAs (miRNAs) are small (∼ 19-22 nucleotides) noncoding RNA molecules whose function is the regulation of gene expression. Their uncommon biochemical characteristics (eg, their resistance to degradation because of extreme temperature and pH fluctuations, freeze-thaw cycles, long storage times in frozen conditions, and RNAse digestion) and their presence in a wide range of different biological fluids and the relatively low number of individual miRNAs make these molecules good biomarkers in different clinical conditions. In addition, miRNAs are suitable therapeutic targets as their expression can be modulated by different available strategies. The aim of the present review is to offer clinicians a global perspective of miRNA, covering their structure and nomenclature, biogenesis, effects on gene expression, regulation of expression, and features as disease biomarkers and therapeutic targets, with special attention to ARDS. Because of the early stage of research on miRNAs applied to ARDS, attention has been focused on how knowledge sourced from basic and translational research could inspire future clinical studies.

Emodin ameliorates lipopolysaccharides-induced corneal inflammation in rats

AIM

To investigate the effect of emodin on pseudomonas aeruginosa lipopolysaccharides (LPS)-induced corneal inflammation in rats.

METHODS

Corneal infection was induced by pseudomonas aeruginosa LPS in Wistar rats. The inflammation induced by LPS were examined by slit lamp microscope and cytological checkup of aqueous humor. Corneal tissue structure was observed by hematoxylin and eosin (HE) staining. The activation of nuclear factor kappaB (NF-κB) was determined by Western blot. Messenger ribonucleic acid (mRNA) of tumor necrosis factor-α (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) in LPS-challenged rat corneas were measured with reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Typical manifestations of acute corneal inflammation were observed in LPS-induce rat model, and the corneal inflammatory response and structure were improved in rats pretreated with emodin. Treatment with emodin could improve corneal structure, reduce corneal injure by reducing corneal inflammatory response. Emodin could inhibit the decreasing lever of inhibitor of kappaB alpha (IкBα) express, and the mRNA expression of TNF-α and ICAM-1 in corneal tissues was also inhibited by emodin. The differences were statistically significant between groups treated with emodin and those without treatment (P<0.01).

CONCLUSION

Emodin could ameliorate LPS-induced corneal inflammation, which might via inhibiting the activation of NF-κB.

Saturated hydrogen saline attenuates endotoxin-induced lung dysfunction

BACKGROUND

Acute lung injury induced by lipopolysaccharides (LPSs) is caused by pulmonary inflammation and pulmonary vascular permeability. Activation of p38 mitogen-activated protein kinase causes inflammation, and proinflammatory cytokines and oxidative stress induce autophagy, a catabolic mechanism responsible for protein degradation and recycling of damaged proteins and cytoplasmic organelles. If not controlled, excessive autophagy responses can result in cell death.

MATERIALS AND METHODS

In this study, we pretreated rats with saturated hydrogen saline, and examined the molecular mechanism by which saturated hydrogen saline attenuates LPS-induced acute lung dysfunction. Sixty-four male Sprague-Dawley rats were randomly assigned to one of three groups--a control group, an LPS group, or an LPS plus saturated hydrogen saline (LPS + H2) group.

RESULTS

Treatment with saturated hydrogen saline prolonged the median survival time of rats and reduced lung dysfunction induced by LPS. Moreover, saturated hydrogen saline significantly attenuated LPS-mediated induction of serum tumor necrosis factor α, interleukin 6, myeloperoxidase, and malondialdehyde (P < 0.05).

CONCLUSIONS

Autophagosomes were found in the cytoplasm of type II alveolar epithelial cells of LPS-treated rats, and light chain 3 protein (LC3)I/II was increased by LPS treatment. In contrast, saturated hydrogen saline decreased the number of autophagosomes and LC3I/II expression. Saturated hydrogen saline also attenuated the LPS-mediated increase in apoptosis and p38 expression. Taken together, saturated hydrogen saline may attenuate LPS-induced acute lung dysfunction in rats by reducing inflammation, autophagy, and apoptosis involving the p38 mitogen-activated protein kinase signaling pathway.

PARP inhibitor, olaparib ameliorates acute lung and kidney injury upon intratracheal administration of LPS in mice

We have previously shown that PARP-1 inhibition provides protection against lung inflammation in the context of asthma and acute lung injury. Olaparib is a potent new generation PARP inhibitor that has been approved for human testing. The present work was designed to evaluate its beneficial potential against LPS-induced acute lung injury and acute kidney injury upon intratracheal administration of the endotoxin in mice. Administration of olaparib at different doses, 30 min after LPS treatment showed that single intraperitoneal injection of the drug at 5 mg/kg b.wt. reduced the total number of inflammatory cells particularly neutrophils in the lungs. This was associated with reduced pulmonary edema as the total protein content in the bronchoalveolar fluid was found to be decreased substantially. Olaparib provided strong protection against LPS-mediated secondary kidney injury as reflected by restoration of serum levels of urea, creatinine, and uric acid toward normal. The drug restored the LPS-mediated redox imbalance toward normal in lung and kidney tissues as assessed by measuring malondialdehyde and GSH levels. Finally, RT-PCR data revealed that olaparib downregulates the LPS-induced expression of NF-κB-dependent genes namely TNF-α, IL-1β, and VCAM-1 in the lungs without altering the expression of total p65NF-κB. Overall, the data suggest that olaparib has a strong potential to protect against LPS-induced lung injury and associated dysfunctioning of kidney in mice. Given the fact that olaparib is approved by FDA for human testing, our findings can pave the way for testing of the drug on humans inflicted with acute lung injury.

Switching off key signaling survival molecules to switch on the resolution of inflammation

Inflammation is a physiological response of the immune system to injury or infection but may become chronic. In general, inflammation is self-limiting and resolves by activating a termination program named resolution of inflammation. It has been argued that unresolved inflammation may be the basis of a variety of chronic inflammatory diseases. Resolution of inflammation is an active process that is fine-tuned by the production of proresolving mediators and the shutdown of intracellular signaling molecules associated with cytokine production and leukocyte survival. Apoptosis of leukocytes (especially granulocytes) is a key element in the resolution of inflammation and several signaling molecules are thought to be involved in this process. Here, we explore key signaling molecules and some mediators that are crucial regulators of leukocyte survival in vivo and that may be targeted for therapeutic purposes in the context of chronic inflammatory diseases.