Role of nitric oxide in inflammation

A novel donor-acceptor fluorescent probe for the fluorogenic/ chromogenic detection and bioimaging of nitric oxide

Nitric oxide (NO) plays an essential role in regulating various physiological and pathological processes. This has spurred various efforts to develop feasible methods for the detection of NO. Herein we designed and synthesized a novel donor-acceptor fluorescent probe Car-NO for the selective and specific detection of NO. Reaction of Car-NO with NO generated a new donor-acceptor structure with strong intramolecular charge transfer (ICT) effect, and led to remarkable chromogenic change from yellow to blue and dramatic fluorescence quenching. Car-NO exhibited high selectivity, excellent sensitivity, and rapid response for the detection of NO. In addition, the nanoparticles prepared from Car-NO (i.e., Car-NO NPs) showed strong NIR emission and high selectivity/sensitivity. Car-NO NPs was successfully employed to image both endogenous and exogenous NO in HeLa and RAW 264.7 cells. The present findings reveal that Car-NO is a promising probe for the detection and bioimaging of NO.

Salivary and serum nitric oxide synthase, macrophage inflammatory protein 1 alpha and macrophage migration inhibitory factor levels in periodontal disease

Objective

Periodontal disease is multifactorial inflammatory disease involving both gingivitis and periodontitis. Inducible nitric oxide synthase (iNOS), macrophage inflammatory protein 1 alpha (MIP-1α) and macrophage migration inhibitory factor (MIF) are mediators contributing to the progression of periodontal diseases with distinct functions. The aim of this study is to evaluate the local and systemic iNOS, MIP-1α and MIF concentrations in patients having periodontal disease with different severities.

Design

The study was conducted on 88 individuals equally divided into four groups; 1) Periodontally Healthy 2) Gingivitis 3) Stage I-II Periodontitis 4) Stage III-IV Periodontitis. Saliva and serum samples were obtained from each individual and then periodontal examinations were performed. Plaque and bleeding on probing indexes, probing depths and clinical attachment levels were measured on each tooth to determine the periodontal status. Concentrations of iNOS, MIP-1α and MIF were measured with enzyme-linked immunosorbent assay.

Results

Patients with stage I-II and stage III-IV periodontitis had more iNOS levels than periodontally healthy people in serum and saliva (p ≤ 0,001 for serum; p < 0,05 for saliva). Stage III-IV periodontitis group had significantly more serum-iNOS levels than that in gingivitis group (p = 0,005). When compared with periodontally healthy individuals, MIP-1α levels in stage III-IV periodontitis patients were measured significantly more in saliva; (p = 0,016) but less in serum (p = 0,006) samples. More serum-MIF concentrations were observed in stage I-II periodontitis groups than that in periodontally healthy individuals (p < 0,05).

Conclusion

Increased salivary and serum iNOS and serum-MIF levels in different stages of periodontitis suggest that these molecules might be involved in periodontal disease pathogenesis. Also, oral microenvironment may stimulate the enhanced MIP-1α concentration in advanced periodontitis cases.

Potential of hydroethanolic leaf extract of Ocimum sanctum in ameliorating redox status and lung injury in COPD: an in vivo and in silico study

Oxidative stress and inflammation are hypothesised as the main contributor for Chronic Obstructive Pulmonary Disease (COPD). Cigarette smoke (CS), a major cause of COPD leads to inflammation resulting in recruitment of neutrophils and macrophages which are rich sources of oxidants. Activation of these cells produces excess oxidants and depletes antioxidants resulting in stress. Presently, effective drug for COPD is limited; therefore, novel compounds from natural sources, including plants are under exploration. The present study aims to investigate the protective effect of Ocimum sanctum leaf extract (OLE) in CS - induced model of COPD. Exposure to CS was performed thrice a week for 8 weeks and OLE (200 mg/kg and 400 mg/kg) was administered an hour before CS exposure. Control group (negative control) were exposed to ambient air while COPD group was exposed to CS (positive control). Administration of OLE doses reduced inflammation, decreased oxidant concentration and increased antioxidant concentration (p < 0.01). Molecular docking studies between the major phytocompounds of OLE (Eugenol, Cyclohexane and Caryophyllene) and antioxidant enzymes Superoxide dismutase (SOD), Catalase, Glutathione peroxidase (GPx), Glutathione reductase (GR) and Glutathione S Transferase (GST) showed strong binding interaction in terms of binding energy. In vivo and in silico findings for the first time indicates that OLE extract significantly alleviates oxidative stress by its potent free radical scavenging property and strong interaction with antioxidant enzymes. OLE extract may prove to be a therapeutic option for COPD prevention and treatment.

Two Argan Oil Phytosterols, Schottenol and Spinasterol, Attenuate Oxidative Stress and Restore LPS-Dysregulated Peroxisomal Functions in Acox1-/- and Wild-Type BV-2 Microglial Cells

Oxidative stress and inflammation are the key players in neuroinflammation, in which microglia dysfunction plays a central role. Previous studies suggest that argan oil attenuates oxidative stress, inflammation, and peroxisome dysfunction in mouse brains. In this study, we explored the effects of two major argan oil (AO) phytosterols, Schottenol (Schot) and Spinasterol (Spina), on oxidative stress, inflammation, and peroxisomal dysfunction in two murine microglial BV-2 cell lines, wild-ype (Wt) and Acyl-CoA oxidase 1 (Acox1)-deficient cells challenged with LPS treatment. Herein, we used an MTT test to reveal no cytotoxicity for both phytosterols with concentrations up to 5 µM. In the LPS-activated microglial cells, cotreatment with each of these phytosterols caused a significant decrease in intracellular ROS production and the NO level released in the culture medium. Additionally, Schot and Spina were able to attenuate the LPS-dependent strong induction of Il-1β and Tnf-α mRNA levels, as well as the iNos gene and protein expression in both Wt and Acox1-/- microglial cells. On the other hand, LPS treatment impacted both the peroxisomal antioxidant capacity and the fatty acid oxidation pathway. However, both Schot and Spina treatments enhanced ACOX1 activity in the Wt BV-2 cells and normalized the catalase activity in both Wt and Acox1-/- microglial cells. These data suggest that Schot and Spina can protect cells from oxidative stress and inflammation and their harmful consequences for peroxisomal functions and the homeostasis of microglial cells. Collectively, our work provides a compelling argument for the protective mechanisms of two major argan oil phytosterols against LPS-induced brain neuroinflammation.

Anti-Inflammatory Activity of Cajanin, an Isoflavonoid Derivative Isolated from Canavalia lineata Pods

The bioactive components of Canavalia lineata (Thunb.) DC pods were investigated using bioactivity-guided isolation, and the chemical structures of flavonoids 1–3, isoflavonoid derivatives 4–11, and phenolic compounds 12 and 13 were identified by comparing NMR, MS, and CD spectral data with previously reported spectroscopic data. Compounds 1–13 were evaluated for their anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages. Among these compounds, the isoflavonoid derivative cajanin (7) exhibited the most potent anti-inflammatory activity (IC₅₀ of NO = 19.38 ± 0.05 µM; IC₅₀ of IL-6 = 7.78 ± 0.04 µM; IC₅₀ of TNF-α = 26.82 ± 0.11 µM), exerting its anti-inflammatory effects by suppressing the activation and nuclear translocation of the transcription factor NF-κB by phosphorylating IκB and p65. These results suggested that cajanin (7) may be a potential candidate for improving the treatment of inflammatory diseases.

A new benzaldehyde from the coral-derived fungus Aspergillus terreus C23-3 and its anti-inflammatory effects via suppression of MAPK signaling pathway in RAW264.7 cells

Marine fungi are important members of the marine microbiome, which have been paid growing attention by scientists in recent years. The secondary metabolites of marine fungi have been reported to contain rich and diverse compounds with novel structures (Chen et al., 2019). Aspergillus terreus, the higher level marine fungus of the Aspergillus genus (family of Trichocomaceae, order of Eurotiales, class of Eurotiomycetes, phylum of Ascomycota), is widely distributed in both sea and land. In our previous study, the coral-derived A. terreus strain C23-3 exhibited potential in producing other biologically active (with antioxidant, acetylcholinesterase inhibition, and anti-inflammatory activity) compounds like arylbutyrolactones, territrems, and isoflavones, and high sensitivity to the chemical regulation of secondary metabolism (Yang et al., 2019, 2020; Nie et al., 2020; Ma et al., 2021). Moreover, we have isolated two different benzaldehydes, including a benzaldehyde with a novel structure, from A. terreus C23-3 which was derived from Pectinia paeonia of Xuwen, Zhanjiang City, Guangdong Province, China.

A cysteine-triggered fluorogenic donor base on native chemical ligation for tracking H2S delivery in vivo

A hydrogen sulfide (H₂S) donor is a fundamental molecular tool used as an exogenous source in biological studies and therapies. However, finding a controllable and visual fluorescent H₂S donor is difficult. We report a new H₂S donor, HSD560, the H₂S release of which is triggered by cysteine. Importantly, the H₂S generation is accompanied with enhanced green fluorescence, which could be utilized to track H₂S release in cells using microscopy. H₂S release from HSD560 undergoes a non-enzymatic native chemical ligation (NCL) process, which provides an accurate match with activated fluorescence and localization of H₂S in zebrafish.

Embelia Laeta aqueous extract suppresses acute inflammation via decreasing COX-2/iNOS expression and inhibiting NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Embelia laeta (L.) Mez., which is called Suanjifeng in Chinese ethnic Yao medicine, is traditionally for inflammation-related diseases, such as oral ulcer, sore throat, enteritis, and rheumatoid arthritis. However, the biological properties and the underlying mechanisms of Embelia laeta still need further studies.

AIM OF THIS STUDY

The present study aims to investigate the anti-inflammatory effect and its underlying mechanisms of Embelia laeta.

MATERIALS AND METHODS

In this study, except acute toxicity experiments, Kunming (KM) mice of either sex were enrolled to establish inflammatory model induced by xylene, acetic acid and carrageenan, respectively. Mice were randomly divided into different groups and pretreated by oral gavage with different doses of Embelia laeta aqueous extract (ELAE) (2.5, 5, 10 g/kg) and 10 mg/kg of Indo for 7 days. Ear edema, vascular permeability, abdominal writhing, and paw edema degree were detected in related experiments. Moreover, in the carrageenan-induced paw edema mice model, histological changes were detected by H&E staining. MDA, MPO and NO were detected by assay kit. Proinflammatory cytokines of IFN-γ, TNF-α, IL-1β, IL-6 and PGE₂ were detected by ELISA. Additionally, COX-2, iNOS and NF-κB pathway-related proteins were detected by Western blotting.

RESULTS

Results showed that the ELAE evoked an obvious dose-dependent inhibition of ear edema induced by xylene, paw edema induced by carrageenan, as well as suppressing the increase of vascular permeability and writhing times elicited by acetic acid. Histopathological analysis indicated that ELAE could significantly decrease the cellular infiltration in paw tissue. ELAE showed antioxidant property through markedly decrease the MDA level and MPO activity in edema paw. In addition, ELAE decreased the proinflammatory cytokines IFN-γ, TNF-α, IL-1β, IL-6, PGE₂ and NO that induced by carrageenan. Western blotting results also showed that ELAE could obviously downregulate the COX-2 and iNOS expression. Further analysis revealed that ELAE also inhibited NF-κB from the cytoplasm to the nucleus and stabilize the conversion of IκBα.

CONCLUSION

ELAE had powerful anti-inflammatory property, which might be had a close relationship with mediating proinflammatory cytokines production, decreasing the COX-2 and iNOS expression, and inhibiting the activation of NF-κB signaling pathway.

Calystegia soldanella Extract Exerts Anti-Oxidative and Anti-Inflammatory Effects via the Regulation of the NF-κB/Nrf-2 Pathways in Mouse Macrophages

Plant polyphenols are widely used to treat various inflammatory diseases, owing to their ability to suppress reactive oxygen species production and the expression of inflammatory cytokines. Herein, we investigated phenolic compounds from Calystegia soldanella using UPLC Q-TOF MS/MS and their antioxidative and anti-inflammatory activities were analyzed. The C. soldanella ethyl acetate fraction (CsEF) had the strongest antioxidative activity, given its high polyphenol compound content. It also exhibited anti-inflammatory effects, inhibiting the production of inflammatory cytokines such as NO, PGE2, IL-1β, IL-6, and TNF-α in LPS-stimulated mouse macrophages. CsEF activated the nuclear transcription factor Nrf-2, thereby upregulating antioxidant enzymes such as HO-1 and NQO-1 and inhibiting NF-κB expression, which in turn, suppressed the expression of COX-2, iNOS, and inflammatory cytokines, ultimately exerting anti-inflammatory effects. Further, UPLC-Q-TOF-MS/MS was used to analyze the polyphenol compound contents in CsEF. The quercetin glycosides isoquercitrin and quercitrin were the primary flavonoid compounds, while the caffeic acid derivatives, chlorogenic acid and dicaffeoylquinic acid, were the primary phenolic acids. Thus, C. soldanella, which had only a limited use thus far as a medicinal plant, may serve as a natural medicinal resource for treating inflammatory diseases.

Structural and biochemical characterization of the novel serpin Iripin-5 from Ixodes ricinus

Iripin-5 is the main Ixodes ricinus salivary serpin, which acts as a modulator of host defence mechanisms by impairing neutrophil migration, suppressing nitric oxide production by macrophages and altering complement functions. Iripin-5 influences host immunity and shows high expression in the salivary glands. Here, the crystal structure of Iripin-5 in the most thermodynamically stable state of serpins is described. In the reactive-centre loop, the main substrate-recognition site of Iripin-5 is likely to be represented by Arg342, which implies the targeting of trypsin-like proteases. Furthermore, a computational structural analysis of selected Iripin-5-protease complexes together with interface analysis revealed the most probable residues of Iripin-5 involved in complex formation.

Geometric Features of the Pial Arteriolar Networks in Spontaneous Hypertensive Rats: A Crucial Aspect Underlying the Blood Flow Regulation

Background

Several studies indicate that hypertension causes major changes in the structure of the vessel wall by affecting the regulation of blood supply to the tissues. Recently, it has been observed that capillary blood flow is also considerably influenced by the structural arrangement of the microvascular networks that undergo rarefaction (reduction of the perfused vessel number). Therefore, this study aimed to assess the geometric arrangements of the pial arteriolar networks and the arteriolar rhythmic diameter changes in spontaneously hypertensive rats (SHRs).

Methods

Fluorescence microscopy was utilized to observe in vivo the pial microcirculation through a closed cranial window. Pial arterioles were classified according to Strahler’s method. The arteriolar rhythmic diameter changes were evaluated by a generalization short-time Fourier transform.

Result

Young SHRs showed four orders of vessels while the adult ones only three orders. The diameter, length, and branching number obeyed Horton’s law; therefore, the vessels were distributed in a fractal manner. Larger arterioles showed more asymmetrical branches than did the smaller ones in young SHRs, while in adult SHRs smaller vessels presented asymmetrical branchings. In adult SHRs, there was a significant reduction in the cross-sectional area compared with the young SHRs: this implies an increase in peripheral resistance. Young and adult age-matched normotensive rats did not show significant alterations in the geometric arteriolar arrangement with advancing age, both had four orders of arteriolar vessels, and the peripheral resistance did not change significantly. Conversely, the frequency components evaluated in arteriolar rhythmic diameter changes of young and adult SHRs showed significant differences because of a reduction in the frequency components related to endothelial activity detected in adult SHRs.

Conclusion

In conclusion, hypertension progressively causes changes in the microarchitecture of the arteriolar networks with a smaller number of vessels and consequent reduced conductivity, characteristic of rarefaction. This was accompanied by a reduction in the formation and release of independent and dependent – endothelial nitric oxide components regulating arterial vasomotion.

Nitric oxide and viral infection: Recent developments in antiviral therapies and platforms

Nitric oxide (NO) is a gasotransmitter of great significance to developing the innate immune response to many bacterial and viral infections, while also modulating vascular physiology. The generation of NO from the upregulation of endogenous nitric oxide synthases serves as an efficacious method for inhibiting viral replication in host defense and warrants investigation for the development of antiviral therapeutics. With increased incidence of global pandemics concerning several respiratory-based viral infections, it is necessary to develop broad therapeutic platforms for inhibiting viral replication and enabling more efficient host clearance, as well as to fabricate new materials for deterring viral transmission from medical devices. Recent developments in creating stabilized NO donor compounds and their incorporation into macromolecular scaffolds and polymeric substrates has created a new paradigm for developing NO-based therapeutics for long-term NO release in applications for bactericidal and blood-contacting surfaces. Despite this abundance of research, there has been little consideration of NO-releasing scaffolds and substrates for reducing passive transmission of viral infections or for treating several respiratory viral infections. The aim of this review is to highlight the recent advances in developing gaseous NO, NO prodrugs, and NO donor compounds for antiviral therapies; discuss the limitations of NO as an antiviral agent; and outline future prospects for guiding materials design of a next generation of NO-releasing antiviral platforms.

Plantamajoside protects H9c2 cells against hypoxia/reoxygenation-induced injury through regulating the akt/Nrf2/HO-1 and NF-κB signaling pathways

Myocardial ischemia/reperfusion (I/R) injury has been found to be associated with oxidative stress. Plantamajoside (PMS) is a major compound of Plantago asiatica that was reported to possess cardioprotective and antioxidant effects. The current study was designed to investigate the effect of PMS on myocardial I/R injury. Rat cardiomyocytes H9c2 cells were exposed to hypoxia/reoxygenation (H/R) to establish in vitro model of myocardial I/R injury. MTT assay proved that H9c2 cells viability was significant reduced under H/R treatment, while the reduction was ameliorated by PMS. H/R-induced ROS production in H9c2 cells was suppressed by PMS. The decreased activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in the H/R group were effectively elevated by PMS. In addition, treatment with PMS attenuated H/R-stimulated production of TNF-α, IL-6 and IL-1β in H9c2 cells. Besides, PMS significantly suppressed bax expression and caspase 3 activity, as well as increased bcl-2 expression in H/R-stimulated H9c2 cells. Furthermore, we also found that PMS significantly enhanced the activation of Akt/Nrf2/HO-1 signaling pathway and suppressed the activation of NF-κB signaling pathway in H/R-stimulated H9c2 cells. These results provided substantial evidence that PMS protected against myocardial I/R injury via attenuating oxidative stress, inflammatory response and apoptosis. The protective effects of PMS were attributed to the Akt/Nrf2/HO-1 and NF-κB signaling pathways.

Rubus chingii Hu: an overview of botany, traditional uses, phytochemistry, and pharmacology

Rubus chingii Hu, a member of the rosaceae family, is extensively distributed in China and Japan. Its unripe fruits (Fupenzi in Chinese) have a long history of use as an herbal tonic in traditional Chinese medicine for treating various diseases commonly associated with kidney deficiency, and they are still in use today. Phytochemical investigations on the fruits and leaves of R. chingii indicate the presence of terpenoids, flavonoids, steroids, alkaloids, phenylpropanoids, phenolics, and organic acids. Extracts or active substances from this plant are reported to have various pharmacological properties, including antioxidant, anti-inflammatory, antitumor, antifungal, antithrombotic, antiosteoporotic, hypoglycemic, and central nervous system-regulating effects. This review provides up-to-date information on the botanical characterizations, traditional usages, chemical constituents, pharmacological activities, toxicity, and quality control of R. chingii. Possible directions for future research are also briefly proposed. This review aims to supply fundamental data for the further study of R. chingii and contribute to the development of its clinical use.

Anti-nociceptive and anti-inflammatory activities of ethanol extract and fractions of Morus mesozygia Stapf (Moraceae) leaves and its underlying mechanisms in rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Morus mesozygia Stapf (Moraceae), commonly known as African mulberry, is traditionally used for the treatment of inflammatory disorders such as rheumatism and dermatitis.

AIM

This work aimed to evaluate the anti-nociceptive and anti-inflammatory effects of its ethanol (EEMm) extract, and ethylacetate fraction (EAFMm).

METHODS

The anti-nociceptive and anti-inflammatory effect of ethanol extracts of M. mesozygia (EEMm), and its ethylacetate (EAFMm) and residual aqueous fraction (RAFMm) was evaluated in hotplate, acetic acid and formalin tests and as well in membrane stabilizing assay and carrageenan-induced paw oedema models. Mechanism of anti-inflammation of EAFMm was investigated in the carrageenan-induced air-pouch model.

RESULTS

In the hot plate test of nociception, only the EAFMm showed significant (p < 0.05) anti-nociceptive activity. The extract and fractions significantly reduced number of writhing with EAFMm (400 mg/kg) showing highest inhibition (66.5%) in the acetic acid-induced writhing in mice. EEMm and EAFMm (400 mg/kg) significantly reduced the paw licking time in the early and late phases of the formalin test. The extract and fractions showed good membrane stabilizing activity comparable to indomethacin. EAFMm (100 and 400 mg/kg) showed the highest inhibition of paw oedema (53.4% and 58.1%) in the carrageenan-induced paw oedema model. The EAFMm (100 and 400 mg/kg) reduced exudate volume relative to carrageenan-control (2.64 ± 0.22, 2.08 ± 0.15 vs 3.83 ± 0.18 mL) and neutrophils (8.98 ± 1.36, 8.00 ± 0.22 vs 20.51 ± 1.14) in carrageenan-induced pouch. EAFMm significantly reduced exudate volume, pro-inflammatory cytokines and the expression of COX-2 and NFκB.

CONCLUSION

M. mesozygia leaves demonstrated anti-nociceptive and anti-inflammatory activities by suppressing oxidative stress, pro-inflammatory cytokines, cyclooxygenase-2, and nuclear factor kappa B.

The Metabolomic Underpinnings of Symptom Burden in Patients With Multiple Chronic Conditions

Over 25% of the adult population in the United States suffers from multiple chronic conditions, with numbers continuing to rise. Those with multiple chronic conditions often experience symptoms or symptom clusters that undermine their quality of life and ability to self-manage. Importantly, symptom severity in those with even the same multiple chronic conditions varies, suggesting that the mechanisms driving symptoms in patients with multiple chronic conditions are not fixed but may differ in ways that could make them amenable to targeted interventions. In this manuscript we describe at a metabolic level, the symptom experience of persons with multiple chronic conditions, including how symptoms may synergize or cluster across multiple chronic conditions to augment one's symptom burden. To guide this discussion, we consider the metabolites and metabolic pathways known to span multiple adverse health conditions and associate with severe symptoms of fatigue, depression, and anxiety and their cluster. We also describe how severe versus mild symptoms, and their associated metabolites and metabolic pathways, may vary, depending on the presence of covariates; two of which, sex as a biological variable and the contribution of gut microbiota dysbiosis, are discussed in additional detail. Intertwining metabolomics and symptom science into nursing research, offers the unique opportunity to better understand how the metabolites and metabolic pathways affected in those with multiple chronic conditions may initiate or exacerbate symptom presence within a given individual, ultimately allowing clinicians to develop targeted interventions to improve the health quality of patients their families.

β-Cyclodextrin Inhibits Monocytic Adhesion to Endothelial Cells through Nitric Oxide-Mediated Depletion of Cell Adhesion Molecules

Cyclodextrins (CDs) are used as drug delivery agents. In this study, we examined whether CDs have an inflammatory effect on endothelial cells. First, we found that β-CD promoted cell proliferation in bovine aortic endothelial cells and elevated nitric oxide (NO) production through dephosphorylation of threonine-495 (T-495) in endothelial nitric oxide synthetase (eNOS). Dephosphorylation of T-495 is known to activate eNOS. Phosphorylation of T-495 was found to be catalyzed by protein kinase Cε (PKCε). We then found that β-CD inhibits binding of PKCε to diacylglycerol (DAG) via formation of a β-CD-DAG complex, indicating that β-CD inactivates PKCε. Furthermore, β-CD controls activation of PKCε by reducing the recruitment of PKCε into the plasma membrane. Finally, β-CD inhibits expression of intercellular and vascular cell adhesion molecule-1 by increasing NO via control of PKCε/eNOS and suppression of THP-1 cell adhesion to endothelial cells. These findings imply that β-CD plays an important role in anti-inflammatory processes.

Tumor-Treating Fields Induce RAW264.7 Macrophage Activation Via NK-κB/MAPK Signaling Pathways

Objective:

Tumor-treating fields are currently used to successfully treat various cancers; however, the specific pathways associated with its efficacy remain unknown in the immune responses. Here, we evaluated tumor-treating fields–mediated initiation of the macrophage-specific immune response.

Materials and Methods:

We subjected RAW 264.7 mouse macrophages to clinically relevant levels of tumor-treating fields (0.9 V/cm, 150 kHz) and evaluated alterations in cytokine expression and release, as well as cell viability. Additionally, we investigated the status of immunomodulatory pathways to determine their roles in tumor-treating fields–mediated immune activation.

Results and Discussion:

Our results indicated that tumor-treating fields treatment at 0.9 V/cm decreased cell viability and increased cytokine messenger RNA/protein levels, as well as levels of nitric oxide and reactive oxygen species, relative to controls. The levels of tumor necrosis factor α, interleukin 1β, and interleukin 6 were markedly increased in tumor-treating fields–treated RAW 264.7 cells cocultured with 4T1 murine mammary carcinoma cells compared with those in 4T1 or RAW 264.7 cells with or without tumor-treating fields treatment. Moreover, the viability of 4T1 cells treated with the conditioned medium of tumor-treating fields–stimulated RAW 264.7 cells decreased, indicating that macrophage activation by tumor-treating fields effectively killed the tumor cells. Moreover, tumor-treating fields treatment activated the nuclear factor κB and mitogen-activated protein kinase pathways involved in immunomodulatory signaling.

Conclusion:

These results provide critical insights into the mechanisms through which tumor-treating fields affect macrophage-specific immune responses and the efficacy of this method for cancer treatment.

Injury-Induced Effectors of Neuropathic Pain

Injuries typically result in the development of neuropathic pain, which decreases in parallel with wound healing. However, the pain may remain after the injury appears to have healed, which is generally associated with an ongoing underlying pro-inflammatory state. Injury induces many cells to release factors that contribute to the development of a pro-inflammatory state, which is considered an essential first step towards wound healing. However, pain elimination requires a transition of the injury site from pro- to anti-inflammatory. Therefore, developing techniques that eliminate chronic pain require an understanding of the cells resident at and recruited to injury sites, the factors they release, that promote a pro-inflammatory state, and promote the subsequent transition of that site to be anti-inflammatory. Although a relatively large number of cells, factors, and gene expression changes are involved in these processes, it may be possible to control a relatively small number of them leading to the reduction and elimination of chronic neuropathic pain. This first of two papers examines the roles of the most salient cells and mediators associated with the development and maintenance of chronic neuropathic pain. The following paper examines the cells and mediators involved in reducing and eliminating chronic neuropathic pain.

The structure and function of Iristatin, a novel immunosuppressive tick salivary cystatin

To successfully feed, ticks inject pharmacoactive molecules into the vertebrate host including cystatin cysteine protease inhibitors. However, the molecular and cellular events modulated by tick saliva remain largely unknown. Here, we describe and characterize a novel immunomodulatory cystatin, Iristatin, which is upregulated in the salivary glands of feeding Ixodes ricinus ticks. We present the crystal structure of Iristatin at 1.76 Å resolution. Purified recombinant Iristatin inhibited the proteolytic activity of cathepsins L and C and diminished IL-2, IL-4, IL-9, and IFN-γ production by different T-cell populations, IL-6 and IL-9 production by mast cells, and nitric oxide production by macrophages. Furthermore, Iristatin inhibited OVA antigen-induced CD4+ T-cell proliferation and leukocyte recruitment in vivo and in vitro. Our results indicate that Iristatin affects wide range of anti-tick immune responses in the vertebrate host and may be exploitable as an immunotherapeutic.

4-O-Carboxymethylascochlorin Inhibits Expression Levels of on Inflammation-Related Cytokines and Matrix Metalloproteinase-9 Through NF-κB/MAPK/TLR4 Signaling Pathway in LPS-Activated RAW264.7 Cells

Toll-like receptor 4 (TLR4) and matrix metalloproteinase-9 (MMP-9) are known to play important roles in inflammatory diseases such as arteriosclerosis and plaque instability. The purpose of this study was to perform the effect of 4-O-carboxymethylascochlorin (AS-6) on MMP-9 expression in lipopolysaccharide (LPS)-induced murine macrophages and signaling pathway involved in its anti-inflammatory effect. Effect of AS-6 on MAPK/NF-κB/TLR4 signaling pathway in LPS-activated murine macrophages was examined using ELISA, Western blotting, reverse transcription polymerase chain reaction (RT-PCR) and fluorescence immunoassay. MMP-9 enzyme activity was examined by gelatin zymography. AS-6 significantly suppressed MMP-9 and MAPK/NF-κB expression levels in LPS-stimulated murine macrophages. Expression levels of inducible nitric oxide synthase (iNOS), COX2, MMP-9, JNK, ERK, p38 phosphorylation, and NF-κB stimulated by LPS were also decreased by AS-6. Moreover, AS-6 suppressed TLR4 expression and dysregulated LPS-induced activators of transcription signaling pathway. The results of this study showed that AS-6 can inhibit LPS-stimulated inflammatory response by suppressing TLR4/MAPK/NF-κB signals, suggesting that AS-6 can be used to induce the stability of atherosclerotic plaque and prevent inflammatory diseases in an in vitro model.

EGFR inhibitors from cancer to inflammation: Discovery of 4-fluoro-N-(4-(3-(trifluoromethyl)phenoxy)pyrimidin-5-yl)benzamide as a novel anti-inflammatory EGFR inhibitor

EGFR inhibitors are well-known as anticancer agents. Quite differently, we report our effort to develop EGFR inhibitors as anti-inflammatory agents. Pyrimidinamide EGFR inhibitors eliciting low micromolar IC₅₀ and the structurally close non-EGFR inhibitor urea analog were synthesized. Comparing their nitric oxide (NO) production inhibitory activity in peritoneal macrophages and RAW 246.7 macrophages indicated that their anti-inflammatory activity in peritoneal macrophages might be a sequence of EGFR inhibition. Further evaluations proved that compound 4d significantly and dose-dependently inhibits LPS-induced iNOS expression and IL-1β, IL-6, and TNF-α production via NF-κB inactivation in peritoneal macrophages. Compound 4d might serve as a lead compound for development of a novel class of anti-inflammatory EGFR inhibitors.

Preventive effect of oligonol on nitric oxide and reactive oxygen species production through regulation of nuclear factor kappa B signaling pathway in RAW 264.7 macrophage cells against sodium nitroprusside

Oligonol attenuated SNP-induced oxidative stress and inflammatory responsesviaregulation of the NF-κB signalling pathway in RAW 264.7 macrophage cells.

Pathophysiology of Acute Illness and Injury

The pathophysiology of acute illness and injury recognizes three main effectors: infection, trauma, and ischemia-reperfusion injury. Each of them can act by itself or in combination with the other two in developing a systemic inflammatory reaction syndrome (SIRS) that is a generalized reaction to the morbid event. The time course of SIRS is variable and influenced by the number and severity of subsequent insults (e.g., reparative surgery, acquired hospital infections). It occurs simultaneously with a complex of counter-regulatory mechanisms (compensatory anti-inflammatory response syndrome, CARS) that limit the aggressive effects of SIRS. In adjunct, a progressive dysfunction of the acquired (lymphocytes) immune system develops with increased risk for immunoparalysis and associated infectious complications. Both humoral and cellular effectors participate to the development of SIRS and CARS. The most important humoral mediators are pro-inflammatory (IL-1β, IL-6, IL-8, IL-12) and anti-inflammatory (IL-4, IL-10) cytokines and chemokines, complement, leukotrienes, and PAF. Effector cells include neutrophils, monocytes, macrophages, lymphocytes, and endothelial cells. The endothelium is a key factor for production of remote organ damage as it exerts potent chemo-attracting effects on inflammatory cells, allows for leukocyte trafficking into tissues and organs, and promotes further inflammation by cytokines release. Moreover, the loss of vasoregulatory properties and the increased permeability contribute to the development of hypotension and tissue edema. Finally, the disseminated activation of the coagulation cascade causes the widespread deposition of microthrombi with resulting maldistribution of capillary blood flow and ultimately hypoxic cellular damage. This mechanism together with increased vascular permeability and vasodilation is responsible for the development of the multiple organ dysfunction syndrome (MODS).

Schisandra Chinensis Lignans Suppresses the Production of Inflammatory Mediators Regulated by NF-κB, AP-1, and IRF3 in Lipopolysaccharide-Stimulated RAW264.7 Cells

Schisandra Fructus (SF) is a traditional Chinese herb used in the treatment of inflammatory disorders like hepatitis. One of the main anti-inflammatory components of SF is the lignans. However, the underlying anti-inflammatory mechanism of Schisandra Chinensis lignans (SCL) remains unclear. This study aims to investigate the effects of SCL on inflammatory mediators in lipopolysaccharide-stimulated RAW264.7 cells and explore the underlying mechanism. The production of nitric oxide (NO) was determined by Griess reaction. ELISA was used to determine cytokine levels and chemokines secretion. To estimate protein levels and enzyme activities, we employed Western blotting. Nuclear localization of NF-κB, AP-1, and IRF3 was detected using immunofluorescence analyses. The results showed that SCL significantly reduced the release of inflammatory mediators, including NO and PGE2, which may be related to down-regulation of iNOS and COX-2 expression. The production of cytokines and chemokines was suppressed by SCL treatment. SCL also decreased the phosphorylation of IKKα/β, IκB-α, Akt, TBK1, ERK, p38, JNK, NF-κB (p65), AP-1 (c-Jun), and IRF3 in RAW264.7 macrophages activated with LPS. The nuclear protein levels and nuclear translocation of AP-1, NF-κB and IRF3 were suppressed by SCL. These results indicated that SCL suppressed the IKKα/β/NF-κB, MAPKs/AP-1 and TBK1/IRF3 signaling pathways in LPS-stimulated RAW264.7 macrophages.

Gut microbiota and inflammation in chronic kidney disease and their roles in the development of cardiovascular disease

The health and proper functioning of the cardiovascular and renal systems largely depend on crosstalk in the gut-kidney-heart/vessel triangle. Recent evidence suggests that the gut microbiota has an integral function in this crosstalk. Mounting evidence indicates that the development of chronic kidney and cardiovascular diseases follows chronic inflammatory processes that are affected by the gut microbiota via various immune, metabolic, endocrine, and neurologic pathways. Additionally, deterioration of the function of the cardiovascular and renal systems has been reported to disrupt the original gut microbiota composition, further contributing to the advancement of chronic cardiovascular and renal diseases. Considering the interaction between the gut microbiota and the renal and cardiovascular systems, we can infer that interventions for the gut microbiota through diet and possibly some medications can prevent/stop the vicious cycle between the gut microbiota and the cardiovascular/renal systems, leading to a decrease in chronic cardiovascular and renal diseases.

Bilirubin, a new therapeutic for kidney transplant?

In patients with end-stage renal disease, kidney transplantation has been associated with numerous benefits, including increased daily activity, and better survival rates. However, over 20% of kidney transplants result in rejection within five years. Rejection is primarily due to a hypersensitive immune system and ischemia/reperfusion injury. Bilirubin has been shown to be a potent antioxidant that is capable of potentially reversing or preventing damage from reactive oxygen species generated from ischemia and reperfusion. Additionally, bilirubin has several immunomodulatory effects that can dampen the immune system to promote organ acceptance. Increased bilirubin has also been shown to have a positive impact on renal hemodynamics, which is critical post-transplantation. Lastly, bilirubin levels have been correlated with biomarkers of successful transplantation. In this review, we discuss a multitude of potentially beneficial effects that bilirubin has on kidney acceptance of transplantation based on numerous clinical trials and animal models. Exogenous bilirubin delivery or increasing endogenous levels pre- or post-transplantation may have therapeutic benefits.

Butyrolactone-I from Coral-Derived Fungus Aspergillus terreus Attenuates Neuro-Inflammatory Response via Suppression of NF-κB Pathway in BV-2 Cells

Butyrolactone-I (ZB5-1) from the coral-derived fungus Aspergillus terreus was investigated in this study to estimate its anti-neuroinflammatory effects on lipopolysaccharide (LPS)-induced BV-2 microglia cells. MTT assay indicated that ZB5-1 in tested concentrations had no cytotoxicity on BV-2 cells, and significantly reduced the production of nitric oxide (NO), measured using Griess reagent, and interleukin-1 beta (IL-1β), detected by enzyme-linked immunosorbent assay (ELISA). ZB5-1 also down-regulated the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose-dependent manner by Western blot analysis. Moreover, the effect of ZB5-1 on the nuclear factor-κB (NF-κB) signaling pathway was studied via the expression of phosphorylation of NF-κB p65 and inhibitor of NF-κB (IκB), and the nuclear translocation of NF-κB p65 respectively. The results showed that ZB5-1 could inhibit the phosphorylation of p65 and IκB. Furthermore, molecular docking study suggested that ZB5-1 bound at the active sites of NF-κB to prevent its translocation to the nucleus. Therefore, we suggest ZB5-1 has a potential to reduce the anti-inflammatory response in LPS-induced BV-2 cells.

Analysis of NO-suppressing activity of Strawberry Wine supplemented with ball-milled achenes

Inflammation is generally thought to be involved in the development of several chronical diseases, therefore, phytochemicals to modulate immune responses has attracted great interests. The objective of the present study was to evaluate the potential anti-inflammatory effects of wine supplemented using ball-milled achene on modulating NO production and inducible nitric oxide synthase (iNOS) expression. Ball-milled achenes were added in strawberry must prior to fermentation, and the wine samples were then concentrated and extracted with water and/or ethanol prior to analysis. Bioactivities of wine extracts were evaluated using the cell viability assay, cell cycle measurements, NO production and iNOS expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Treatments of achenes supplemented strawberry wine extract up to 100 μg/mL inhibited the proliferation of LPS-stimulated RAW264.7 cell via affecting the progression of cell cycle. Moreover, no detectable cytotoxicity in RAW264.7 cells was observed. The supplemented wine extract suppressed the action of LPS and led to a decreased NO production in stimulated cells. The inhibitory effect of the wine extract on NO production was determined to be a 25-40% decrease in the level of 25-100 μg/mL, in contrast to a 10% decrease for conventional wine samples. Additionally, an alcoholic wine extract (100 μg/mL) led to a 40.31% decrease in iNOS expression in LPS-stimulated cells, which was more effective than the same dose of tocopherol. The results show that strawberry wine supplemented with ball-milled achenes causes a substantial inhibition of NO production, and this biofunction is exerted via the down-regulation of iNOS expression.

Optimized-SopungSunkiwon, a Herbal Formula, Attenuates Aβ Oligomer-Induced Neurotoxicity in Alzheimer's Disease Models

Alzheimer's disease (AD), the most common form of dementia, is an age-related neurodegenerative disease that is characterized by memory dysfunction, neuronal cell damage, and neuroinflammation. It is believed that AD-related pathology is mostly due to the overproduction of Aβ, especially the oligomeric form (AβO), in the brain. Evidence of the effects of multifunctional medicinal herbs in the treatment of AD has been steadily increasing. Optimized-SopungSunkiwon (OSS), a multiherbal formulation that is composed of six medicinal herbs derived from SopungSunkiwon, is a traditional medicine that is prescribed for neurodegenerative disorders in elderly patients. We previously reported that OSS showed an antiamnesic and memory enhancing effect in mice, but it is unknown whether OSS has a protective effect against AβO neurotoxicity. In this study, we investigated the effects of OSS in AD models induced by AβO in vitro and in vivo. We found that OSS protected neuronal cells and inhibited the generation of nitric oxide and reactive oxygen species against AβO toxicity in vitro. These results were confirmed by in vivo data that oral administration of OSS for 14 days attenuated memory impairments and neuronal cell death by modulating gliosis, glutathione depletion, and synaptic damage in the mouse hippocampus induced by AβO.

Dysifragilone A inhibits LPS‑induced RAW264.7 macrophage activation by blocking the p38 MAPK signaling pathway

Dysifragilone A, a sesquiterpene aminoquinone based on a rearranged avarone skeleton, has been previously isolated and identified from the South China Sea sponge Dysidea fragilis. In the present study, anti‑inflammatory activity and the underlying molecular mechanism of dysifragilone A were studied using the classical inflammation model of lipopolysaccharide (LPS)‑activated RAW264.7 macrophage cells and an MTT assay, Griess method, ELISA and western blotting were used. The results revealed that dysifragilone A significantly reduced the release of inflammatory mediators and inflammatory cytokines in activated RAW264.7 cells, including nitric oxide (NO), prostaglandin E2,(PGE2) and interleukin‑6 (IL‑6). The protein expression levels of inducible nitric oxide synthase (iNOS), cyclooxygenase‑2 (COX‑2), and the enzymatic activity of iNOS and COX‑2 were also inhibited by dysifragilone A in a dose dependent manner. Further mechanistic investigations suggested that the anti‑inflammatory activity of dysifragilone A results from the suppression of p38 mitogen‑activated protein kinase (MAPK) activation in LPS‑activated macrophages; however, this was not associated with inhibition of the extracellular signal‑regulated kinase (ERK) or c‑Jun N‑terminal kinase (JNK) signaling pathways. Therefore, dysifragilone A and similar compounds may be anti‑inflammatories that have potential to be used in the clinic.

Layer-by-Layer Engineered Microbicide Drug Delivery System Targeting HIV-1 gp120: Physicochemical and Biological Properties

The purpose of this study was to engineer a model anti-HIV microbicide (tenofovir) drug delivery system targeting HIV-1 envelope glycoprotein gp120 (HIV-1 g120) for the prevention of HIV sexual transmission. HIV-1 g120 and mannose responsive particles (MRP) were prepared through the layer-by-layer coating of calcium carbonate (CaCO₃) with concanavalin A (Con A) and glycogen. MRP average particle size ranged from 881.7 ± 15.45 nm to 1130 ± 15.72 nm, depending on the number of Con A layers. Tenofovir encapsulation efficiency in CaCO₃ was 74.4% with drug loading of 16.3% (w/w). MRP was non-cytotoxic to Lactobacillus crispatus, human vaginal keratinocytes (VK2), and murine macrophage RAW 264.7 cells and did not induce any significant proinflammatory nitric oxide release. Overall, compared to control, no statistically significant increase in proinflammatory cytokine IL-1α, IL-1β, IL-6, MKC, IL-7, and interferon-γ-inducible protein 10 (IP10) levels was observed. Drug release profiles in the presence of methyl α-d-mannopyranoside and recombinant HIV-1 envelope glycoprotein gp120 followed Hixson-Crowell and Hopfenberg kinetic models, indicative of a surface-eroding system. The one Con A layer containing system was found to be the most sensitive (∼2-fold increase in drug release vs control SFS:VFS) at the lowest HIV gp120 concentration tested (25 μg/mL). Percent mucoadhesion, tested ex vivo on porcine vaginal tissue, ranged from 10% to 21%, depending on the number of Con A layers in the formulation. Collectively, these data suggested that the proposed HIV-1 g120 targeting, using MRP, potentially represent a safe and effective template for vaginal microbicide drug delivery, if future preclinical studies are conclusive.

Krüppel-like factor 4 regulates the expression of inducible nitric oxide synthase induced by TNF-α in human fibroblast-like synoviocyte MH7A cells

Krüppel-like factor 4 (KLF4), a zinc finger transcription factor, has been implicated in the inflammation mediated by macrophages and endothelial cells by regulating the expression of inflammatory mediators. Here, we investigated whether KLF4 affects the expression of inducible nitric oxide synthase (iNOS), an important inflammatory mediator, in the human RA fibroblast-like synovial cell line MH7A. A pcDNA3.1-KLF4 plasmid or short interfering RNA KLF4 was transfected into MH7A cells, and the iNOS expression and nitric oxide (NO) production were analyzed by quantitative PCR, immunoblotting, and nitrite measurement. The iNOS promoter activity was determined by luciferase assay. The results showed overexpression of KLF4 increased iNOS expression and NO production in the presence or absence of TNF-α. Conversely, KLF4 knockdown markedly reduced iNOS expression and NO production induced by TNF-α. KLF4 activated the transcription activity of iNOS promoter in MH7A cells stimulated by TNF-α. This study indicates that KLF4 is important for regulating the expression of iNOS by TNF-α in human synoviocytes.

Leaves of Raphanus sativus L. Shows Anti-Inflammatory Activity in LPS-Stimulated Macrophages via Suppression of COX-2 and iNOS Expression

Raphanus sativus L. (RS) is a cruciferous vegetable that is widely consumed in Korea. The anticancer activity of leaves of RS (RSL) extract has been investigated; however, no studies focused on its anti-inflammatory effects. Therefore, the aim of the current study was to evaluate the anti-inflammatory effects of RSL extract. In brief, RSL powder was fractionated into n-hexane, chloroform, ethyl acetate, n-butanol, and water-soluble fractions. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells were treated with each fraction for initial screening. It was found that the chloroform fraction significantly inhibited nitric oxide release in LPS-stimulated RAW264.7 cells with a half maximal inhibitory concentration value of 196 μg/mL. In addition, the mRNA and protein expression levels of inducible nitric oxide synthase, measured using reverse transcriptase-polymerase chain reaction and western blotting, respectively, were reduced in a concentration-dependent manner. Moreover, the inflammatory cyclooxygenase-2 enzyme expression decreased. Furthermore, the expression of nuclear factor-kappa B (NF-κB), the key regulator of the transcriptional activation of the inflammatory cytokine genes, was reduced by the RSL chloroform fraction. Therefore, the results of our study suggest that RSL exhibits anti-inflammatory effects in LPS-stimulated macrophages via NF-κB inactivation.

Stauntoside B inhibits macrophage activation by inhibiting NF-κB and ERK MAPK signalling

Inflammation is a defensive reaction of body to resist foreign invasion. However, it has been demonstrated that excessive and continuous inflammatory responses contribute to various inflammatory diseases, including rheumatoid arthritis. Nuclear factor-κB (NF-κB) regulates the expression of an array of inflammatory mediators, cytokines and chemokine genes in activated macrophages. Therefore, NF-κB has become an attractive drug target for controlling inflammation. In this study, stauntoside B, a C21 steroidal glycosides compound isolated from a Chinese medicine Cynanchi Stauntonii, was for the first time found to suppress macrophage activation induced by lipopolysaccharide (LPS) in RAW264.7 cells and rat primary peritoneal macrophages and could be a potent NF-κB inhibitor. The results showed that stauntoside B significantly reduced the release of inflammatory mediators in activated RAW264.7 cells and rat peritoneal macrophages, including nitric oxide (NO) and prostaglandin E2 (PGE2). The mRNA expressions of pro-inflammatory mediators and cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), microsomal prostaglandin synthetase-1 (mPGES-1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) as well as the production of TNF-α and IL-6 were also inhibited by stauntoside B. Mechanistic investigation implies that the anti-inflammatory activity of stauntoside B could result from the suppression of LPS-induced IKKα/β activation, IκBα phosphorylation, p65 (ser536) NF-κB phosphorylation, and ERK MAPK activation by stauntoside B treatment in activated macrophages. Meanwhile, stauntoside B could induce apoptosis in LPS-activated macrophages. The current study suggests stauntoside B being a valuable candidate drug for the treatment of inflammatory diseases, especially for NF-κB activation associated inflammatory diseases.

Effect of pecan phenolics on the release of nitric oxide from murine RAW 264.7 macrophage cells

Inflammation is linked to numerous chronic disease states. Phenolic compounds have attracted attention because a number of these compounds possess anti-inflammatory properties. A phenolic crude extract was prepared from pecans and separated by Sephadex LH-20 column chromatography into low- and high-molecular-weight (LMW/HMW) fractions. Anti-inflammatory properties of these fractions were assessed in LPS-stimulated RAW 264.7 murine macrophage cells. NO and reactive oxygen species (ROS) production was monitored after 3 different experimental protocols: (1) pre-treatment with Escherichia coli O111:B4 lipopolysaccharide (LPS); (2) pre-treatment with a pecan crude extract and its fractions; and (3) co-incubation of LPS with a pecan crude extract and its fractions. The LMW fraction displayed a dose-dependent decrease in NO production and a significant decrease from the LPS control in ROS production when cells were either co-incubated with or pre-treated with LPS. The phenolics were characterized by HPLC to help identify those responsible for the observed effect.

Activation of toll-like receptor signaling pathways leading to nitric oxide-mediated antiviral responses

Toll-like receptors (TLRs), well-characterized pattern-recognizing receptors of the innate arm of the immune system, are vital in detecting pathogen-associated molecular patterns (PAMPs). The TLR-PAMP interaction initiates an intracellular signaling cascade, predominantly culminating in upregulation of antiviral components, including inducible nitric oxide synthase (iNOS). After activation, various TLR pathways can promote iNOS production via the myeloid differentiation primary response-88 (MyD-88) adapter protein. Subsequently, iNOS facilitates production of nitric oxide (NO), a highly reactive and potent antiviral molecule that can inhibit replication of RNA and DNA viruses. Furthermore, NO can diffuse freely across cell membranes and elicit antiviral mechanisms in various ways, including direct and indirect damage to viral genomes. This review emphasizes current knowledge of NO-mediated antiviral responses elicited after activation of TLR signaling pathways.

Propitious Therapeutic Modulators to Prevent Blood-Spinal Cord Barrier Disruption in Spinal Cord Injury

The blood-spinal cord barrier (BSCB) is a specialized protective barrier that regulates the movement of molecules between blood vessels and the spinal cord parenchyma. Analogous to the blood-brain barrier (BBB), the BSCB plays a crucial role in maintaining the homeostasis and internal environmental stability of the central nervous system (CNS). After spinal cord injury (SCI), BSCB disruption leads to inflammatory cell invasion such as neutrophils and macrophages, contributing to permanent neurological disability. In this review, we focus on the major proteins mediating the BSCB disruption or BSCB repair after SCI. This review is composed of three parts. Section 1. SCI and the BSCB of the review describes critical events involved in the pathophysiology of SCI and their correlation with BSCB integrity/disruption. Section 2. Major proteins involved in BSCB disruption in SCI focuses on the actions of matrix metalloproteinases (MMPs), tumor necrosis factor alpha (TNF-α), heme oxygenase-1 (HO-1), angiopoietins (Angs), bradykinin, nitric oxide (NO), and endothelins (ETs) in BSCB disruption and repair. Section 3. Therapeutic approaches discusses the major therapeutic compounds utilized to date for the prevention of BSCB disruption in animal model of SCI through modulation of several proteins.

Tumour, Oxidative Stress and Host T Cell Response: Cementing the Dominance

Reactive oxygen species (ROS) and free radicals are produced intrinsically during normal cellular metabolic processes or extrinsically due to ionizing radiations, UV rays, xenobiotic insult, etc. ROS are important signal mediators and are used by the immune system to destroy pathogens, but as these are highly reactive, they also have the capacity to cause DNA damage and alter protein and lipid components of a cell. As a result, cells have evolved a tight regulation of internal redox environment that involves a balanced interplay between free radicals produced and quenched by cellular antioxidants and enzyme systems. Any deregulation of this subtle balance can result in oxidative stress that can lead to various pathological conditions including cancer. Oxidative stress can be a cause of neoplasia, or it can be induced by a growing tumour itself. The link existing between oxidative stress and inflammation is also very strong. Suppressed cellular immune system, especially effector T cell system, is a characteristic of tumour-bearing host. Both the direct oxidative stress caused by tumour cell(s) and oxidative stress mediators present in tumour microenvironment play a significant role in the suppression of effector T cell function and induction of T cell death. This review discusses in detail the complex interplay between tumour-stroma-immune system in the light of oxidative stress that dominates every phase of cancer including initiation, progression and establishment. This review also addresses in detail the mechanisms of oxidative stress-induced T cell dysfunction in tumour-bearing host and also briefly points out the possible therapeutic interventions.

V-PYRRO/NO downregulates mRNA expression levels of leukotriene C4 synthase during hepatic ischemia reperfusion injury in rats via inhibition of the nuclear factor-κB activation pathway

The aim of the present study was to explore the mechanism underlying the effects of a selective liver nitric oxide (NO) donor, O²-vinyl1-(pyrrolidin-1-yl)-diazen-1-ium-1,2-diolate (V-PYRRO/NO), on the gene expression of leukotriene C4 synthase (LTC4S) during hepatic ischemia/reperfusion (I/R). Adult male Sprague-Dawley rats were divided into 3 groups: Sham (control), I/R and V-PYRRO/NO + I/R groups. The liver was subjected to 1 h of partial hepatic ischemia followed by 5 h of reperfusion, saline or V-PYRRO/NO (1.06 µmol/kg/h) administered intravenously. The mRNA expression levels of LTC4S in rat liver tissue were examined by the reverse transcription-polymerase chain reaction method, the protein expression levels of nuclear factor-κB (NF-κB) p65, p50 and IκBα in liver cell lysates and nuclear extracts were detected by western blot analysis. Hepatic mRNA expression of LTC4S was lower in V-PYRRO/NO + I/R group compared to the I/R group. In addition, the protein expression levels of NF-κB p65 and p50 in the nucleus extract were lower in the V-PYRRO/NO + I/R group when compared with the I/R group. However, the IκBα protein in the 3 groups was not changed. Immunohistochemistry staining revealed that the I/R liver exhibited strong cytoplasmic and nuclear staining for NF-κB p65; however, the V-PYRRO/NO + I/R group liver presented slight cytoplasmic and nuclear staining. In conclusion, V-PYRRO/NO may downregulate LTC4S mRNA expression by inhibiting NF-κB activation independent of IκBα during hepatic I/R injury.

Ablation of eNOS does not promote adipose tissue inflammation

Adipose tissue (AT) inflammation is a hallmark characteristic of obesity and an important determinant of insulin resistance and cardiovascular disease; therefore, a better understanding of factors regulating AT inflammation is critical. It is well established that reduced vascular endothelial nitric oxide (NO) bioavailability promotes arterial inflammation; however, the role of NO in modulating inflammation in AT remains disputed. In the present study, 10-wk-old C57BL6 wild-type and endothelial nitric oxide synthase (eNOS) knockout male mice were randomized to either a control diet (10% kcal from fat) or a Western diet (44.9% kcal from fat, 17% sucrose, and 1% cholesterol) for 18 wk (n= 7 or 8/group). In wild-type mice, Western diet-induced obesity led to increased visceral white AT expression of inflammatory genes (e.g., MCP1, TNF-α, and CCL5 mRNAs) and markers of macrophage infiltration (e.g., CD68, ITGAM, EMR1, CD11C mRNAs, and Mac-2 protein), as well as reduced markers of mitochondrial content (e.g., OXPHOS complex I and IV protein). Unexpectedly, these effects of Western diet on visceral white AT were not accompanied by decreases in eNOS phosphorylation at Ser-1177 or increases in eNOS phosphorylation at Thr-495. Also counter to expectations, eNOS knockout mice, independent of the diet, were leaner and did not exhibit greater white or brown AT inflammation compared with wild-type mice. Collectively, these findings do not support the hypothesis that reduced NO production from eNOS contributes to obesity-related AT inflammation.

Global arginine bioavailability, a marker of nitric oxide synthetic capacity, is decreased in PTSD and correlated with symptom severity and markers of inflammation

INTRODUCTION

Psychiatric, physical and biological aspects of posttraumatic stress disorder (PTSD) may be associated with dysfunctions in several cellular processes including nitric oxide (NO) production. NO is synthesized from arginine in a reaction carried out by NO synthase (NOS) enzymes. The recently introduced "global arginine bioavailability ratio" (GABR; ratio of arginine to [ornithine+citrulline]) has been proposed as a reliable approximation of NO synthetic capacity in vivo. The objectives of the present study were to test the hypotheses that (i) subjects with combat-related PTSD have lower GABR scores than combat controls, (ii) GABR score is inversely associated with the severity of psychopathological measures, (iii) GABR score is inversely associated with markers of inflammation.

METHODS

Metabolic profiling for plasma samples (i.e. arginine, citrulline and ornithine) and inflammation markers (interleukin [IL]-6, IL-1β, tumor necrosis factor [TNF]-α, interferon [IFN]-γ and C-reactive protein [CRP]) were assessed in 56 combat-exposed males with PTSD and 65 combat-exposed males without PTSD. We assessed severity of PTSD (Clinician Administered PTSD Scale [CAPS]) and depression (Beck Depression Inventory-II [BDI-II]) as well as history of early life trauma (Early Trauma Inventory [ETI]) and affectivity (Positive and Negative Affect Schedule [PANAS]).

RESULTS

The GABR value was (i) significantly lower in PTSD subjects compared to controls (p=0.001), (ii) significantly inversely correlated with markers of inflammation including IL6 (p=0.04) and TNFα (p=0.02), and (iii) significantly inversely correlated with CAPS current (p=0.001) and lifetime (p<0.001) subscales, ETI (p=0.045) and PANAS negative (p=0.006). Adding antidepressant use or MDD diagnosis as covariates led to similar results. Adding age and BMI as covariates also led to similar results, with the exception of IL6 and ETI losing their significant association with GABR.

DISCUSSION

This study provides the first evidence that global arginine bioavailability, a marker of NO synthetic capacity in vivo, is lower in veterans with PTSD and is negatively associated with some markers of inflammation as well as with measures of PTSD symptom severity, negative affectivity and childhood adverse experiences. These findings add to the accumulating evidence that specific cellular dysfunction may be associated with the symptomatology of PTSD and may help to explain the higher burden of cardio-metabolic disturbances seen in this disorder.

Insights into the Role of Chemokines, Damage-Associated Molecular Patterns, and Lymphocyte-Derived Mediators from Computational Models of Trauma-Induced Inflammation

SIGNIFICANCE

Traumatic injury elicits a complex, dynamic, multidimensional inflammatory response that is intertwined with complications such as multiple organ dysfunction and nosocomial infection. The complex interplay between inflammation and physiology in critical illness remains a challenge for translational research, including the extrapolation to human disease from animal models.

RECENT ADVANCES

Over the past decade, we and others have attempted to decipher the biocomplexity of inflammation in these settings of acute illness, using computational models to improve clinical translation. In silico modeling has been suggested as a computationally based framework for integrating data derived from basic biology experiments as well as preclinical and clinical studies.

CRITICAL ISSUES

Extensive studies in cells, mice, and human blunt trauma patients have led us to suggest (i) that while an adequate level of inflammation is required for healing post-trauma, inflammation can be harmful when it becomes self-sustaining via a damage-associated molecular pattern/Toll-like receptor-driven feed-forward circuit; (ii) that chemokines play a central regulatory role in driving either self-resolving or self-maintaining inflammation that drives the early activation of both classical innate and more recently recognized lymphoid pathways; and (iii) the presence of multiple thresholds and feedback loops, which could significantly affect the propagation of inflammation across multiple body compartments.

FUTURE DIRECTIONS

These insights from data-driven models into the primary drivers and interconnected networks of inflammation have been used to generate mechanistic computational models. Together, these models may be used to gain basic insights as well as serving to help define novel biomarkers and therapeutic targets.

Bilirubin inhibits the up-regulation of inducible nitric oxide synthase by scavenging reactive oxygen species generated by the toll-like receptor 4-dependent activation of NADPH oxidase

It has been previously shown that bilirubin prevents the up-regulation of inducible nitric oxide synthase (iNOS) in response to LPS. The present study examines whether this effect is exerted through modulation of Toll-Like Receptor-4 (TLR4) signaling. LPS-stimulated iNOS and NADPH oxidase (Nox) activity in RAW 264.7 murine macrophages was assessed by measuring cellular nitrate and superoxide ( [Formula: see text] ) production, respectively. The generation of both nitrate and [Formula: see text] in response to LPS was suppressed by TLR4 inhibitors, indicating that activation of iNOS and Nox is TLR4-dependent. While treatment with superoxide dismutase (SOD) and bilirubin effectively abolished LPS-mediated [Formula: see text] production, hydrogen peroxide and nitrate release were inhibited by bilirubin and PEG-catalase, but not SOD, supporting that iNOS activation is primarily dependent upon intracellular H2O2. LPS treatment increased nuclear translocation of the redox-sensitive transcription factor Hypoxia Inducible Factor-1α (HIF-1α), an effect that was abolished by bilirubin. Cells transfected with murine iNOS reporter constructs in which the HIF-1α-specific hypoxia response element was disrupted exhibited a blunted response to LPS, supporting that HIF-1α mediates Nox-dependent iNOS expression. Bilirubin, but not SOD, blocked the cellular production of interferon-β, while interleukin-6 production remained unaffected. These data support that bilirubin inhibits the TLR4-mediated up-regulation of iNOS by preventing activation of HIF-1α through scavenging of Nox-derived reactive oxygen species. Bilirubin also suppresses interferon-β release via a ROS-independent mechanism. These findings characterize potential mechanisms for the anti-inflammatory effects of bilirubin.

Are sensory TRP channels biological alarms for lipid peroxidation?

Oxidative stress induces numerous biological problems. Lipid oxidation and peroxidation appear to be important steps by which exposure to oxidative stress leads the body to a disease state. For its protection, the body has evolved to respond to and eliminate peroxidation products through the acquisition of binding proteins, reducing and conjugating enzymes, and excretion systems. During the past decade, researchers have identified a group of ion channel molecules that are activated by oxidized lipids: transient receptor potential (TRP) channels expressed in sensory neurons. These ion channels are fundamentally detectors and signal converters for body-damaging environments such as heat and cold temperatures, mechanical attacks, and potentially toxic substances. When messages initiated by TRP activation arrive at the brain, we perceive pain, which results in our preparing defensive responses. Excessive activation of the sensory neuronal TRP channels upon prolonged stimulations sometimes deteriorates the inflammatory state of damaged tissues by promoting neuropeptide release from expresser neurons. These same paradigms may also work for pathologic changes in the internal lipid environment upon exposure to oxidative stress. Here, we provide an overview of the role of TRP channels and oxidized lipid connections during abnormally increased oxidative signaling, and consider the sensory mechanism of TRP detection as an alert system.

Hydrogen sulfide and nitric oxide interactions in inflammation

Together with carbon monoxide (CO), nitric oxide (NO) and hydrogen sulfide (H2S) form a group of physiologically important gaseous transmitters, sometimes referred to as the "gaseous triumvirate". The three molecules share a wide range of physical and physiological properties: they are small gaseous molecules, able to freely penetrate cellular membranes; they are all produced endogenously in the body and they seem to exert similar biological functions. In the cardiovascular system, for example, they are all vasodilators, promote angiogenesis and protect tissues against damage (e.g. ischemia-reperfusion injury). In addition, they have complex roles in inflammation, with both pro- and anti-inflammatory effects reported. Researchers have focused their efforts in understanding and describing the roles of each of these molecules in different physiological systems, and in the past years attention has also been given to the gases interaction or "cross-talk". This review will focus on the role of NO and H2S in inflammation and will give an overview of the evidence collected so far suggesting the importance of their cross-talk in inflammatory processes.