Induction Of Inflammatory Mediators Research Articles

Expression of the Metalloproteinase ADAM8 Is Upregulated in Liver Inflammation Models and Enhances Cytokine Release In Vitro

Acute and chronic liver inflammation is driven by cytokine and chemokine release from various cell types in the liver. Here, we report that the induction of inflammatory mediators is associated with a yet undescribed upregulation of the metalloproteinase ADAM8 in different murine hepatitis models. We further show the importance of ADAM8 expression for the production of inflammatory mediators in cultured liver cells. As a model of acute inflammation, we investigated liver tissue from lipopolysaccharide- (LPS-) treated mice in which ADAM8 expression was markedly upregulated compared to control mice. In vitro, stimulation with LPS enhanced ADAM8 expression in murine and human endothelial and hepatoma cell lines as well as in primary murine hepatocytes. The enhanced ADAM8 expression was associated with an upregulation of TNF-α and IL-6 expression and release. Inhibition studies indicate that the cytokine response of hepatoma cells to LPS depends on the activity of ADAM8 and that signalling by TNF-α can contribute to these ADAM8-dependent effects. The role of ADAM8 was further confirmed with primary hepatocytes from ADAM8 knockout mice in which TNF-α and IL-6 induction and release were considerably attenuated. As a model of chronic liver injury, we studied liver tissue from mice undergoing high-fat diet-induced steatohepatitis and again observed upregulation of ADAM8 mRNA expression compared to healthy controls. In vitro, ADAM8 expression was upregulated in hepatoma, endothelial, and stellate cell lines by various mediators of steatohepatitis including fatty acid (linoleic-oleic acid), IL-1β, TNF-α, IFN-γ, and TGF-β. Upregulation of ADAM8 was associated with the induction and release of proinflammatory cytokines (TNF-α and IL-6) and chemokines (CX3CL1). Finally, knockdown of ADAM8 expression in all tested cell types attenuated the release of these mediators. Thus, ADAM8 is upregulated in acute and chronic liver inflammation and is able to promote inflammation by enhancing expression and release of inflammatory mediators.

Cross-talk between IFN-γ and TWEAK through miR-149 amplifies skin inflammation in psoriasis

Psoriasis is a chronic inflammatory skin disease with disturbed interplay between immune cells and keratinocytes. Astrong IFN-γ signature is characteristic for psoriasis skin, but the role of IFN-γ has been elusive. MicroRNAs are short RNAs regulating gene expression. Our aim was to investigate the role of miR-149 in psoriasis and in the inflammatory responses of keratinocytes. miR-149 expression was measured by quantitative RT-PCR in keratinocytes isolated from healthy skin and lesional and nonlesional psoriasis skin. Synthetic miR-149 was injected intradermally into the back skin of mice, and imiquimod was applied to induce psoriasis-like skin inflammation, which was then evaluated at the morphologic, histologic, and molecular levels. miR-149 was transiently overexpressed or inhibited in keratinocytes in combination with IFN-γ- and/or TNF-related weak inducer of apoptosis (TWEAK)-treatment. Here we report a microRNA-mediated mechanism by which IFN-γ primes keratinocytes to inflammatory stimuli. Treatment with IFN-γ results in a rapid and long-lasting suppression of miR-149 in keratinocytes. Depletion of miR-149 in keratinocytes leads to widespread transcriptomic changes and induction of inflammatory mediators with enrichment of the TWEAK pathway. We show that IFN-γ-mediated suppression of miR-149 leads to amplified inflammatory responses to TWEAK. TWEAK receptor (TWEAKR/Fn14) is identified as a novel direct target of miR-149. The invivo relevance of this pathway is supported by decreased miR-149 expression in psoriasis keratinocytes, as well as by the protective effect of synthetic miR-149 in the imiquimod-induced mouse model of psoriasis. Our data define a new mechanism, in which IFN-γ primes keratinocytes for TWEAK-induced inflammatory responses through suppression of miR-149, promoting skin inflammation.

Cantharidin-Induced Skin Blister as an In Vivo Model of Inflammation.

The cantharidin-induced skin blister is a simple model for investigating cell migration and inflammatory mediator production at a site of inflammation. Application of cantharidin solution to the ear pinna results in formation of a blister with cell influx and induction of inflammatory mediators at the skin site, as well as local swelling of the ear pinna. The model can be used for investigating anti-inflammatory compounds, such as dexamethasone, and for preclinical drug discovery research, especially in areas where neutrophilic inflammation plays a role in disease pathophysiology. The cantharidin blister model is one of very few translational models described in humans, and the mechanism of inflammation induction is comparable in mice and man. In human studies, the cantharidin blister assay has been used to assess the effects of potential new therapies in early-stage clinical studies. © 2021 Novartis AG. Basic Protocol 1: Application of cantharidin to induce ear inflammation Basic Protocol 2: Assessment of ear edema Basic Protocol 3: Assessment of inflammatory mediators in ear tissue Basic Protocol 4: Histological assessment of ear tissue.

Biogenic Silver Nanoparticles Can Control Toxoplasma gondii Infection in Both Human Trophoblast Cells and Villous Explants.

The combination of sulfadiazine and pyrimethamine plus folinic acid is the conventional treatment for congenital toxoplasmosis. However, this classical treatment presents teratogenic effects and bone marrow suppression. In this sense, new therapeutic strategies are necessary to reduce these effects and improve the control of infection. In this context, biogenic silver nanoparticles (AgNp-Bio) appear as a promising alternative since they have antimicrobial, antiviral, and antiparasitic activity. The purpose of this study to investigate the action of AgNp-Bio in BeWo cells, HTR-8/SVneo cells and villous explants and its effects against Toxoplasma gondii infection. Both cells and villous explants were treated with different concentrations of AgNp-Bio or combination of sulfadiazine + pyrimethamine (SDZ + PYZ) in order to verify the viability. After, cells and villi were infected and treated with AgNp-Bio or SDZ + PYZ in different concentrations to ascertain the parasite proliferation and cytokine production profile. AgNp-Bio treatment did not reduce the cell viability and villous explants. Significant reduction was observed in parasite replication in both cells and villous explants treated with silver nanoparticles and classical treatment. The AgNp-Bio treatment increased of IL-4 and IL-10 by BeWo cells, while HTR8/SVneo cells produced macrophage migration inhibitory factor (MIF) and IL-4. In the presence of T. gondii, the treatment induced high levels of MIF production by BeWo cells and IL-6 by HTR8SV/neo. In villous explants, the AgNp-Bio treatment downregulated production of IL-4, IL-6, and IL-8 after infection. In conclusion, AgNp-Bio can decrease T. gondii infection in trophoblast cells and villous explants. Therefore, this treatment demonstrated the ability to reduce the T. gondii proliferation with induction of inflammatory mediators in the cells and independent of mediators in chorionic villus which we consider the use of AgNp-Bio promising in the treatment of toxoplasmosis in BeWo and HTR8/SVneo cell models and in chorionic villi.

Immunomodulatory activity seen as a result of photobiomodulation therapy in stimulated primary human fibroblasts

ObjectiveOral biofilms burden host responses by induction of inflammatory mediators, exacerbating periodontal inflammation. Photobiomodulation Therapy (PBMT) has been shown to decrease levels of pro-inflammatory cytokines and chemokines. However, optimal wavelengths and exposure doses have not been established. This study investigated the effects of PBMT on human periodontal ligament fibroblasts (hPDLFs) stimulated with inflammatory mediators (LPS, TNF-α, and IL-1β). MethodsCytotoxic effects of laser wavelengths 660 nm and 810 nm were assessed by measuring their effects on cellular dehydrogenase activity. The study was expanded to include 980 nm, 660 nm + 810 nm, and 810 nm + 980 nm. P.g. LPS, TNF-α, and/or IL-1β were added one hour before irradiation, then exposed to laser irradiation to determine the most appropriate stimulus. The levels of INF-γ, IL-6, IL-8, IL-17A/F, and MCP-1 production in stimulated hPDLFs were measured and analyzed. ResultsP.g. LPS was a poor stimulus for hPDLFs, while TNF-α and IL-1β significantly elevated the analytes. The 660 nm laser treatment induced pro-inflammatory cytokines when stimulated, while 810 nm exhibited significant suppression. IL-1β was the stimulus of choice and the 810 nm wavelength alone exhibited anti-inflammatory effects for all analytes except IL-8, while the 810 nm in combination with 660 nm and/or 980 nm exhibited effects similar to 810 nm alone. ConclusionsThe downregulation of inflammatory mediators by the combination or individual treatment with 810 nm wavelength shows promise for the management of periodontal inflammation. PBMT may lead to the development of a novel approach in the management of periodontal disease.

α-Bisabolol, a Dietary Bioactive Phytochemical Attenuates Dopaminergic Neurodegeneration through Modulation of Oxidative Stress, Neuroinflammation and Apoptosis in Rotenone-Induced Rat Model of Parkinson's disease.

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson’s disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.

Bacterial extracellular vesicles isolated from organic dust induce neutrophilic inflammation in the lung.

Inhalation of organic dust is an occupational hazard leading to the development of respiratory symptoms and respiratory diseases. Bioaerosols from concentrated animal feeding operations are rich in bacteria and could carry bacterial extracellular vesicles (EVs) that could induce lung inflammation. It is not known if organic dust contains bacterial EVs and whether they modulate lung inflammation. Herein, we show that poultry organic dust contains bacterial EVs (dust EVs) that induce lung inflammation. Treatment of airway epithelial cells, THP-1-monocytes and -macrophages with dust EVs rapidly induced IL-8, IL-6, ICAM-1, proIL-1β, and TNF-α levels. In airway epithelial cells, induction of inflammatory mediators was due to increased mRNA levels and NF-κB activation. Induction of inflammatory mediators by dust EVs was not inhibited by polymyxin B. Single and repeated treatments of mice with dust EVs increased lung KC, IL-6, and TNF-α levels without significantly altering IL-17A levels. Increases in cytokines were associated with enhanced neutrophil infiltration into the lung. Repeated treatments of mice with dust EVs increased lung mean linear intercept and increased collagen deposition around airways indicating lung remodeling. Peribronchial cell infiltrates and airway epithelial thickening were also observed in treated mice. Because bacterial EVs are nanometer-sized particles, they can reach and accumulate in the bronchiolar and alveolar regions causing lung injury leading to the development of respiratory diseases. Our studies have provided new evidence for the presence of bacterial EVs in organic dust and for their role as one of the causative agents of organic dust-induced lung inflammation and lung injury.

Therapeutic Potential of Targeting Malt1-Dependent TCR Downstream Signaling to Promote the Survival of MHC-Mismatched Allografts.

Strategies targeting T cells are the cornerstone of immunosuppression after solid organ transplantation. The transcription factor NF-κB is a key regulator of downstream T-cell activation and induction of inflammatory mediators; its full activation via antigen receptor engagement requires both the scaffold and the protease activity of the paracaspase Malt1. Experimental studies have highlighted that Malt1-deficient mice were resistant to experimental autoimmune encephalomyelitis, although they lacked peripheral regulatory T cells (Treg). Here, we compared targeting Malt1 versus using calcineurin inhibitors as immunosuppression in a stringent experimental transplantation model. We found that Malt1-deficiency impaired Th1-mediated alloresponses in vitro and in vivo and significantly prolonged MHC-mismatched skin allograft survival, compared to cyclosporine. However, it paradoxically enhanced Th17 differentiation in the transplantation setting. Interestingly, more selective inhibition of Malt1 protease activity in wild-type mouse and human peripheral T cells in vitro led to attenuation of alloreactive Th1 cells, while preserving preexisting Treg in the peripheral T-cell pool, and without promoting Th17 differentiation. Thus, there is a place for further investigation of the role of Malt1 signaling in the setting of transplantation.

Pro-inflammatory Effects of Influenza Type A Virus PB1-F2 Protein-derived Peptide in Lipopolysaccharide-treated Macrophages.

Influenza A virus (IAV) has the potential to cause pandemics with considerable health and socio-economic burdens. A viral protein, polymerase basic 1- frame2 (PB1-F2), as a virulence factor, has pro-apoptotic activity and contributes to viral pathogenesis by delaying viral clearance and inducing inflammation. Macrophages are susceptible to IAV infection and produce high levels of inflammatory cytokines and chemokines. In the present study, the pro-inflammatory effects of PB1-F2 derived peptide was evaluated by measuring the expression of key inflammatory mediators in murine macrophage cell line J774.1. PB1-F2 treated macrophages were examined for nitric oxide (NO) production, inflammatory cytokines, and enzymes expression and pro-inflammatory cytokines secretion using Griess reagent, real-time polymerase chain reaction (PCR) and ELISA, respectively. Our results have shown that PB1-F2 peptide at non-cytotoxic concentrations (0.1-0.8 µmol/mL) had no effect on NO production. When applied to Lipopolysaccharide (LPS)-treated macrophages, PB1-F2 peptide at 0.8 μmol/mLincreasedinducible NO synthase (iNOS), cyclooxygenase (COX)-2, and interleukin (IL)-6 genes expression to 2.02, 3.81, and 3.65 folds, respectively. PB1-F2 at concentrations of 0.4 and 0.8 µm/mL increased tumor necrosis factor (TNF)-α transcription by 4.15 and 5.55 fold. At posttranslational level, TNF-α increased from 166.5±13.88 in LPS-treated cells to 773.6±95.27 and 1485±76.31 at concentrations of 0.4 and 0.8 μmol/mL in PB1-F2 peptide, respectively. However, PB1-F2 Peptide did not have any significant effect on IL-6 production. These findings suggest that PB1-F2 peptide may partly exert its enhancing role in viral pathogenicity through the induction of inflammatory mediators in macrophages. Hence, targeting PB1-F2 peptide would be helpful in the reduction of viral infection complications.

Loss of p27Kip1 leads to expansion of CD4+ effector memory T cells and accelerates colitis-associated colon cancer in mice with a T cell lineage restricted deletion of Smad4

ABSTRACT The cyclin-dependent kinase inhibitor p27Kip1 is a tumor suppressor whose intrinsic activity in cancer cells correlates with tumor aggressiveness, invasiveness, and impaired tumor cell differentiation. Here we explore whether p27Kip1 indirectly influences tumor progression by restricting expansion and survival of effector memory T cell (TEM) populations in a preclinical model of spontaneous colitis-associated colorectal cancer (CAC). We show mRNA and protein expression of p27Kip1 to be significantly decreased in the colons of mice with a T cell-restricted deletion of the TGF-β intermediate, SMAD4 (Smad4TKO). Loss of p27Kip1 expression in T cells correlates with the onset of spontaneous CAC in Smad4TKO mice by 8 months of age. This phenotype is greatly accelerated by the introduction of a germline deletion of CDKN1b (the gene encoding p27Kip1) in Smad4TKO mice (Smad4TKO/p27Kip1-/-, DKO). DKO mice display colon carcinoma by 3 months of age and increased mortality compared to Smad4TKO. Importantly, the phenotype in DKO mice is associated with a significant increase in the frequency of effector CD4 T cells expressing abundant IFN-γ and with a concomitant decrease in Foxp3+ regulatory T cells, both in the intestinal mucosa and in the periphery. In addition, induction of inflammatory mediators (IFN-γ, TNF-γ, IL-6, IL-1β, iNOS) and activation of Stat1, Stat3, and IκB is also observed in the colon as early as 1–2 months of age. Our data suggest that genomic alterations known to influence p27Kip1 abundance in gastrointestinal cancers may indirectly promote epithelial malignancy by augmenting the production of inflammatory mediators from a spontaneously expanding pool of TEM cells.

The peroxisome proliferator-activated receptor-β/δ antagonist GSK0660 mitigates retinal cell inflammation and leukostasis

Diabetic retinopathy (DR) is triggered by retinal cell damage stimulated by the diabetic milieu, including increased levels of intraocular free fatty acids. Free fatty acids may serve as an initiator of inflammatory cytokine release from Müller cells, and the resulting cytokines are potent stimulators of retinal endothelial pathology, such as leukostasis, vascular permeability, and basement membrane thickening. Our previous studies have elucidated a role for peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in promoting several steps in the pathologic cascade in DR, including angiogenesis and expression of inflammatory mediators. Furthermore, PPARβ/δ is a known target of lipid signaling, suggesting a potential role for this transcription factor in fatty acid-induced retinal inflammation. Therefore, we hypothesized that PPARβ/δ stimulates both the induction of inflammatory mediators by Müller cells as well the paracrine induction of leukostasis in endothelial cells (EC) by Müller cell inflammatory products. To test this, we used the PPARβ/δ inhibitor, GSK0660, in primary human Müller cells (HMC), human retinal microvascular endothelial cells (HRMEC) and mouse retina. We found that palmitic acid (PA) activation of PPARβ/δ in HMC leads to the production of pro-angiogenic and/or inflammatory cytokines that may constitute DR-relevant upstream paracrine inflammatory signals to EC and other retinal cells. Downstream, EC transduce these signals and increase their synthesis and release of chemokines such as CCL8 and CXCL10 that regulate leukostasis and other cellular events related to vascular inflammation in DR. Our results indicate that PPARβ/δ inhibition mitigates these upstream (MC) as well as downstream (EC) inflammatory signaling events elicited by metabolic stimuli and inflammatory cytokines. Therefore, our data suggest that PPARβ/δ inhibition is a potential therapeutic strategy against early DR pathology.

360 miR-378a is overexpressed in psoriasis keratinocytes and potentiates IL-17A-mediated inflammatory responses

Psoriasis is an immune-mediated inflammatory skin disease with a strong genetic background, in which an interplay between infiltrating immune cells and keratinocytes contributes to chronic skin inflammation. The cytokine IL-17, produced by Th17 cells and other cell types, is central in the pathogenesis, and its main target cells are keratinocytes in which it induces cytokines, chemokines and antimicrobial peptides, which further amplify inflammation. Recently, we performed next-generation sequencing for small RNAs in keratinocytes separated by magnetic sorting of CD45neg cells from the epidermis from lesional and non-lesional skin from psoriasis patients. One of the miRNAs differentially expressed in psoriasis keratinocytes was miR-378a. Here, we investigated the function of miR-378a in keratinocytes in psoriasis. miR-378a was significantly up-regulated in keratinocytes of psoriasis skin lesions, as evidenced by RNAseq as well as qPCR on sorted keratinocytes obtained from a larger patient cohort. To investigate the regulation of miR-378a, cultured primary human keratinocytes were treated with a panel of cytokines. qPCR expression analysis of miR-378a showed that IL-17A significantly induced miR-378a, while other cytokines studied did not affect its expression. The NF-kB pathway inhibitor BAY 11-7082 prevented the induction of miR-378a by IL17A, indicating that miR-378a is regulated through the NF-kB pathway. Overexpression of miR-378a in primary keratinocytes potentiated IL-17A-mediated induction of inflammatory mediators in keratinocytes, such as the cytokines CCL20 and IL-8, and the antimicrobial peptide hBD2. Our findings suggest that upregulation of miR-378a in keratinocytes of psoriasis lesions enhances their inflammatory response to IL-17A, thereby amplifying IL-17A-mediated inflammation. Inhibition of miR-378a may have therapeutic potential in psoriasis.

Dried Yeast Extracts Curtails Pulmonary Oxidative Stress, Inflammation and Tissue Destruction in a Model of Experimental Emphysema.

Pulmonary emphysema is characterized by a loss of alveolar integrity due to prolonged cigarette smoking and inhaled irritants. Dried yeast extracts (YE) are employed as food additives, savory flavorings, or creation of umami taste sensations. Despite being rich in nutrition, their application as nutraceuticals and functional foods is not investigated much and little is known about the inhibition of pulmonary emphysema. This study examined whether YE ameliorated pulmonary emphysema in mice is evoked by cigarette smoke (CS) and ovalbumin (OVA). Mice were orally administrated with 25–100 mg/kg YE for 8 weeks. Alveolar epithelial A549 cells exposed to lipopolysaccharide or CS extracts (CSE) were supplemented with 10–100 µg/mL YE. Oral YE administration reduced bronchoalveolar lavage fluid leukocytosis in CS-/OVA-exposed mice. YE reduced induction of inflammatory mediators and MMP-12, and diminished reactive oxygen species production and emphysematous alterations in CS-challenged airways. The YE treatment blunted bax/bcl-2 ratio and activation of p53 and caspases in CS-exposed lungs. Apoptotic death was dampened in CSE-loaded YE-supplemented A549 cells. YE curtailed tissue levels of MMP-12 in inflammatory OVA-exposed lungs. YE abrogated the secretion of TNF-α and MCP-1 through blocking NF-κB signaling in endotoxin-loaded A549 cells. Thus, the antioxidant YE may therapeutically ameliorate oxidative stress and inflammatory tissue destruction in emphysematous diseases.

CORRIGENDUM.

CorrigendumCORRIGENDUMPublished Online:06 Aug 2019https://doi.org/10.1152/ajplung.zh5-7683-corr.2019Original articleMoreSectionsPDF (205 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Natarajan K, Meganathan V, Mitchell C, Boggaram V. Organic dust induces inflammatory gene expression in lung epithelial cells via ROS-dependent STAT-3 activation. Am J Physiol Lung Cell Mol Physiol 317: L127–L140, 2019. First published May 1, 2019; doi:10.1152/ajplung.00448.2018.—In Fig. 6A, the actin panel was incorrect in that it inadvertently included two extra bands (the last 2 bands). The corrected figure is shown below with the appropriate bands in the actin panel. The figure legend remains the same, and the correction does not affect the conclusions of the figure or the study.Fig. 6.Effects of Stattic, a STAT-3 inhibitor, on STAT-3 activation and induction of inflammatory mediators in mouse lungs. Female C57BL/6 mice received vehicle or Stattic via intraperitoneal injections 16 and 1 h before intranasal administration of 50 μl of PBS or 20% dust extract (DE). After 3 h, mice were euthanized, and lungs were cleared of blood by perfusing with PBS and homogenized. A and B: levels of pSTAT-3, STAT-3, and actin were determined by Western blot analysis, and pSTAT-3 level was normalized to STAT-3, which had been normalized to actin. Data shown are means ± SE (n = 5 for PBS, n = 6 for DE and Stattic + DE). *P < 0.05, **P < 0.01 according to one-way analysis of variance using Tukey’s multiple-comparison test. C–F: levels of keratinocyte chemoattractant (KC), IL-1β, IL-6, and TNF-α were determined by ELISA and normalized to total protein levels. G: ICAM-1 levels were determined by Western blot analysis and normalized to actin levels. Data shown are means ± SE (n = 6–9). *P < 0.05, **P < 0.01, ****P < 0.0001; ns, not significant according to one-way analysis of variance using Tukey’s multiple-comparison test.Download figureDownload PowerPointThis article has no references to display. Download PDF Previous Back to Top FiguresReferencesRelatedInformation Related ArticlesOrganic dust induces inflammatory gene expression in lung epithelial cells via ROS-dependent STAT-3 activation 02 Jul 2019American Journal of Physiology-Lung Cellular and Molecular Physiology Press Release E-cigarette Use during Pregnancy Creates Lung Dysfunction in Babies - December 8, 2022 More from this issue > Volume 317Issue 2August 2019Pages L303-L303 Copyright & PermissionsCopyright © 2019 the American Physiological Societyhttps://doi.org/10.1152/ajplung.zh5-7683-corr.2019PubMed31386817History Published online 6 August 2019 Published in print 1 August 2019 Metrics

Anti-inflammatory effect of aerial bulblets of Dioscorea japonica Thunb extract through inhibition of NF-κB and MAPK signalling pathway in RAW 264.7.

Yam (Dioscorea japonica Thunb) is a well-known health food in Korea and is widely distributed in the temperate and tropical regions. Although various medical effects of yam have been demonstrated, there is little current knowledge on the efficacy of Youngyeoja (YYJ; the aerial bulblets of the yam plant), their physiological effects, and their mechanism of action. To investigate the anti-inflammatory effects of YYJ, we examined the level of inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells treated with YYJ extract. Nitric oxide (NO) and prostaglandin E2 (PGE2) levels were determined using enzyme-linked immunosorbent assays. Expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were evaluated using real-time polymerase chain reaction and western blotting. In addition, activation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) was detected using western blotting. Treatment of macrophages with LPS markedly induced the production of NO and PGE2. YYJ treatment inhibited the induction of inflammatory mediators and the expression of iNOS and COX-2. More importantly, LPS-induced phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) was suppressed by treatment with YYJ, suggesting YYJ inhibited NF-κB activation. Furthermore, YYJ inhibited the LPS-induced phosphorylation of MAPKs. YYJ was shown to have a potent anti-inflammatory effect in LPS-stimulated RAW 264.7 cells, which may be attributed to its inhibitory effect on NF-κB and MAPK activation, consequently blocking the production of inflammatory factors. Therefore, these results suggest that the YYJ extracts could be used as anti-inflammatory agents.

Multi-walled carbon nanotubes induce stronger migration of inflammatory cells in vitro than asbestos or granular particles but a similar pattern of inflammatory mediators

Biopersistent pro-inflammatory fibers are suspected human carcinogens. Cytotoxicity and transcription of pro- and anti-inflammatory mediators of different fibers were investigated in functional relationship to chemotaxis in vitro as a model for fiber-induced inflammation of the lung. We challenged NR8383 rat macrophages with multi-walled carbon nanotubes (MWCNT) and various asbestos fibers. The resulting cell supernatants were than studied using the Particle-induced Cell Migration Assay (PICMA) and cytotoxicity was determined using the LDH test. Expression of inflammatory mediators was analyzed with qPCR and verified by ELISA. Chrysotile A and the rigid, needle-shaped NM-401 caused the strongest cytotoxic effects and the largest number of migrated cells. In contrast, the MWCNT NM-400, NM-402, and NM403 were apparently non-cytotoxic but induced pronounced cell migration showing a very steep dose response. However, the strength of cell migration and cytotoxicity of the asbestos fibers were correlated. The expression profile of inflammatory mediators was comparable, although cytotoxicity of the MWCNT NM-401 and NM-403 differed strongly. Induction of the corresponding proteins was confirmed for CCL2, CCL3, CXCL1, CXCL3, IL1RA (IL1RN), CSF1, GDF15 and TNFa. Chrysotile A and NM-401 induced much stronger chemotaxis than the non-fibrous particles reported in our previous study. Cytotoxic and chemotactic effects correspond to the induction of inflammatory mediators.

Immunological Responses to the Relapsing Fever Spirochete Borrelia turicatae in Infected Rhesus Macaques: Implications for Pathogenesis and Diagnosis.

The global public health impact of relapsing fever (RF) spirochetosis is significant, since the pathogens exist on five of seven continents. The hallmark sign of infection is episodic fever and the greatest threat is to the unborn. With the goal of better understanding the specificity of B-cell responses and the role of immune responses in pathogenicity, we infected rhesus macaques with Borrelia turicatae (a new world RF spirochete species) by tick bite and monitored the immune responses generated in response to the pathogen. Specifically, we evaluated inflammatory mediator induction by the pathogen, host antibody responses to specific antigens, and peripheral lymphocyte population dynamics. Our results indicate that B. turicatae elicits from peripheral blood cells key inflammatory response mediators (interleukin-1β and tumor necrosis factor alpha), which are associated with preterm abortion. Moreover, a global decline in peripheral B-cell populations was observed in all animals at 14 days postinfection. Serological responses were also evaluated to assess the antigenicity of three surface proteins: BipA, BrpA, and Bta112. Interestingly, a distinction was observed between antibodies generated in nonhuman primates and mice. Our results provide support for the nonhuman primate model not only in studies of prenatal pathogenesis but also for diagnostic and vaccine antigen identification and testing.

Contribution of Cytokines to Tissue Damage During Human Respiratory Syncytial Virus Infection.

The human respiratory syncytial virus (hRSV) remains one of the leading pathogens causing acute respiratory tract infections (ARTIs) in children younger than 2 years old, worldwide. Hospitalizations during the winter season due to hRSV-induced bronchiolitis and pneumonia increase every year. Despite this, there are no available vaccines to mitigate the health and economic burden caused by hRSV infection. The pathology caused by hRSV induces significant damage to the pulmonary epithelium, due to an excessive inflammatory response at the airways. Cytokines are considered essential players for the establishment and modulation of the immune and inflammatory responses, which can either be beneficial or harmful for the host. The deleterious effect observed upon hRSV infection is mainly due to tissue damage caused by immune cells recruited to the site of infection. This cellular recruitment takes place due to an altered profile of cytokines secreted by epithelial cells. As a result of inflammatory cell recruitment, the amounts of cytokines, such as IL-1, IL-6, IL-10, and CCL5 are further increased, while IL-10 and IFN-γ are decreased. However, additional studies are required to elicit the mediators directly associated with hRSV damage entirely. In addition to the detrimental induction of inflammatory mediators in the respiratory tract caused by hRSV, reports indicating alterations in the central nervous system (CNS) have been published. Indeed, elevated levels of IL-6, IL-8 (CXCL8), CCL2, and CCL4 have been reported in cerebrospinal fluid from patients with severe bronchiolitis and hRSV-associated encephalopathy. In this review article, we provide an in-depth analysis of the role of cytokines secreted upon hRSV infection and their potentially harmful contribution to tissue damage of the respiratory tract and the CNS.

Glutathione inhibits expression of the proinflammatory biomarker inducible nitric oxide synthase in hepatocytes

Background: Intracellular glutathione (GSH) plays an important regulatory role in the host response to liver injury. However, there have been few scientific reports on the anti-inflammatory effects of GSH. In the inflamed liver, proinflammatory cytokines stimulate liver cells, followed by expression of inducible nitric oxide synthase (iNOS). Excessive nitric oxide (NO) levels produced by iNOS are one of the factors involved in liver injury. Therefore, inhibiting iNOS induction is important for preventing liver injury. This study aimed to investigate the protective effects of GSH on the liver by examining interleukin (IL)-1β-stimulated hepatocytes.Methods: Primary cultured rat hepatocytes were treated with IL-1β in the presence or absence of GSH. Induction of iNOS and its signaling pathway were analyzed.Results: Addition of GSH decreased IL-1β-induced iNOS protein and mRNA expression levels, which resulted in inhibition of NO production. GSH also decreased tumor necrosis factor (TNF)-α and IL-6 mRNA expression. GSH blocked “type I IL-1 receptor upregulation”, one of the essential signaling pathways for iNOS induction, through inactivation of an upstream kinase, phosphatidylinositol 3-kinase/Akt. In contrast, GSH had no effects on degradation of IκB and activation of NF-ĸB (nuclear translocation and its DNA binding). Transfection experiments revealed that GSH reduced iNOS mRNA levels at the promoter transactivation and mRNA stabilization steps. Delayed administration of GSH after IL-1β addition also inhibited iNOS induction. Conclusions: Our study suggests that GSH affects induction of inflammatory mediators, including iNOS and TNF-α, indicating its therapeutic potential for organ injuries, especially for the liver.Keywords: glutathione, inducible nitric oxide synthase, liver injury, primary cultured hepatocytes, type I interleukin-1 receptor, tumor necrosis factor-α

Differences in Ocular Complications Between Candida albicans and Non-albicans Candida Infection Analyzed by Epidemiology and a Mouse Ocular Candidiasis Model.

Objectives: Candida species are a major cause of hospital infections, including ocular candidiasis, but few studies have examined the propensities of specific species to invade the eye or the unique immunological responses induced. This study examined the frequency and characteristics of species-specific Candida eye infections by epidemiology and experiments using a mouse ocular candidiasis model.Methods: We reviewed medical records of candidemia patients from January 2012 to March 2017. We also evaluated ocular fungal burden, inflammatory cytokine and chemokine profiles, and inflammatory cell profiles in mice infected with Candida albicans, Candida glabrata, or Candida parapsilosis.Results: During the study period, 20 ocular candidiasis cases were diagnosed among 99 candidemia patients examined by ophthalmologists. Although C. parapsilosis was the most frequent candidemia pathogen, only C. albicans infection was significantly associated with ocular candidiasis by multivariate analysis. In mice, ocular fungal burden and inflammatory mediators were significantly higher during C. albicans infection, and histopathological analysis revealed invading C. albicans surrounded by inflammatory cells. Ocular neutrophil and inflammatory monocyte numbers were significantly greater during C. albicans infection.Conclusion: Candida albicans is strongly associated with ocular candidiasis due to greater capacity for invasion, induction of inflammatory mediators, and recruitment of neutrophils and inflammatory monocytes.