Induction Of Inflammatory Molecules Research Articles

Activated clotting factor X mediates mitochondrial alterations and inflammatory responses via protease-activated receptor signaling in alveolar epithelial cells

There is growing evidence for the contribution of the activated coagulation factor X (FXa) in the development of chronic inflammatory lung diseases. Therefore, we aimed to investigate effects of exogenous FXa on mitochondrial and metabolic function as well as the induction of inflammatory molecules in type II alveolar epithelial cells. Effects of FXa on epithelial cells were investigated in A549 cell line. Activation of extracellular signal-regulated kinase (ERK) and induction of inflammatory molecules were examined by immunoblot and gene expression analysis. Mitochondrial function was assessed by the measurement of oxygen consumption during maximal oxidative phosphorylation and quantitative determination of cardiolipin oxidation. Apoptosis was tested using a caspase 3 antibody. Metabolic activity and lactate dehydrogenase assay were applied for the detection of cellular viability.FXa activated ERK1/2 and induced an increase in the expression of pro-inflammatory cytokines, which was prevented by an inhibitor of FXa, edoxaban, or an inhibitor of protease-activated receptor 1, vorapaxar. Exposure to FXa caused mitochondrial alteration with restricted capacity for ATP generation, which was effectively prevented by edoxaban, vorapaxar and GB83 (inhibitor of protease-activated receptor 2). Of note, exposure to FXa did not initiate apoptosis in epithelial cells.FXa-dependent pro-inflammatory state and impairment of mitochondria did not reach the level of significance in lung epithelial cells. However, these effects might limit regenerative potency of lung epithelial cells, particular under clinical circumstances where lung injury causes exposure to clotting factors.

Ultravist Induces the Expression of MCP-1 and VCAM-1 in IL-4-Stimulated HUVECs.

The goal of the present study focused on the adverse reaction of contrast medium (CM) via the induction of inflammatory molecules in human umbilical vein endothelial cells (HUVECs). Ultravist-induced monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) gene expression was markedly increased in interleukin-4 (IL-4)-pretreated HUVECs in a time- and dose-dependent manner and was paralleled by concomitant production of MCP-1 and VCAM-1 proteins. MCP-1 and VCAM-1 gene expression by Ultravist in combination with IL-4 was mediated by the c-Jun N-terminal kinases (JNK1/2) signaling pathway. IL-4-pretreated Ultravist-stimulated HUVECs showed greatly increased migration and adhesion of THP-1 cells. Cell migration was decreased by treatment of CCR2 antagonist, and cell adhesion was also decreased by VCAM-1 blocking antibody. Furthermore, when tested in vivo under similar conditions, MCP-1 protein was significantly increased in Ultravist combined with IL-4-injected mice. Taken together, our findings suggest that MCP-1 blocking may be crucial in preventing the endothelial dysfunction induced by contrast medium in patients with inflammatory disease and atherosclerosis.

The Inflammasome: Regulation of Nitric Oxide and Antimicrobial Host Defence.

Nitric oxide (NO) is a gaseous signalling molecule that plays diverse physiological functions including antimicrobial host defence. During microbial infection, NO is synthesized by inducible NO synthase (iNOS), which is expressed by host immune cells through the recognition of microbial pattern molecules. Therefore, sensing pathogens or their pattern molecules by pattern recognition receptors (PRRs), which are located at the cell surface, endosomal and phagosomal compartment, or in the cytosol, is key in inducing iNOS and eliciting antimicrobial host defence. A group of cytosolic PRRs is involved in inducing NO and other antimicrobial molecules by forming a molecular complex called the inflammasome. Assembled inflammasomes activate inflammatory caspases, such as caspase-1 and caspase-11, which in turn process proinflammatory cytokines IL-1β and IL-18 into their mature forms and induce pyroptotic cell death. IL-1β and IL-18 play a central role in immunity against microbial infection through activation and recruitment of immune cells, induction of inflammatory molecules, and regulation of antimicrobial mediators including NO. Interestingly, NO can also regulate inflammasome activity in an autocrine and paracrine manner. Here, we discuss molecular mechanisms of inflammasome formation and the inflammasome-mediated regulation of host defence responses during microbial infections.

Heat stress-induced memory impairment is associated with neuroinflammation in mice.

BackgroundHeat stress induces many pathophysiological responses and has a profound impact on brain structure. It has been demonstrated that exposure to high temperature induces cognitive impairment in experimental animals and humans. Although the effects of heat stress have long been studied, the mechanisms by which heat stress affects brain structure and cognition not well understood.MethodsIn our longitudinal study of mice exposed to heat over 7, 14, or 42 days, we found that heat stress time dependently impaired cognitive function as determined by Y-maze, passive avoidance, and novel object recognition tests. To elucidate the histological mechanism by which thermal stress inhibited cognitive abilities, we examined heat stress-induced inflammation in the hippocampus.ResultsIn mice subjected to heat exposure, we found: 1) an increased number of glial fibrillary acid protein (GFAP)- and macrophage-1 antigen (Mac-1)-positive cells, 2) up-regulated nuclear factor (NF)-κB, a master regulator of inflammation, and 3) marked increases in cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and cytokine interleukin (IL)-1β and tumor necrosis factor (TNF)-α in the mouse hippocampus. We also observed that neuronal and synaptic densities were degenerated significantly in hippocampal regions after heat exposure, as determined by histological analysis of neuronal nuclei (NeuN), postsynaptic density protein 95 (PSD-95), and synaptophysin expression. Moreover, in heat-exposed mice, we found that the number of cells positive for doublecortin (DCX), a marker of neurogenesis, was significantly decreased compared with control mice. Finally, anti-inflammatory agent minocycline inhibited the heat stress-induced cognitive deficits and astogliosis in mice.ConclusionsTogether, these findings suggest that heat stress can lead to activation of glial cells and induction of inflammatory molecules in the hippocampus, which may act as causative factors for memory loss, neuronal death, and impaired adult neurogenesis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-015-0324-6) contains supplementary material, which is available to authorized users.

Davallialactone Reduces Inflammation and Repairs Dentinogenesis on Glucose Oxidase–induced Stress in Dental Pulp Cells

IntroductionThe chronic nature of diabetes mellitus (DM) raises the risk of oral complication diseases. In general, DM causes oxidative stress to organs. This study aimed to evaluate the cellular change of dental pulp cells against glucose oxidative stress by glucose oxidase with a high glucose state. The purpose of this study was to test the antioxidant character of davallialactone and to reduce the pathogenesis of dental pulp cells against glucose oxidative stress. MethodsThe glucose oxidase with a high glucose concentration was tested for hydroxy peroxide (H2O2) production, cellular toxicity, reactive oxygen species (ROS) formation, induction of inflammatory molecules and disturbance of dentin mineralization in human dental pulp cells. The anti-oxidant effect of Davallilactone was investigated to restore dental pulp cells' vitality and dentin mineralization via reduction of H2O2 production, cellular toxicity, ROS formation and inflammatory molecules. ResultsThe treatment of glucose oxidase with a high glucose concentration increased H2O2 production, cellular toxicity, and inflammatory molecules and disturbed dentin mineralization by reducing pulp cell activity. However, davallialactone reduced H2O2 production, cellular toxicity, ROS formation, inflammatory molecules, and dentin mineralization disturbances even with a long-term glucose oxidative stress state. ConclusionsThe results of this study imply that the development of oral complications is related to the irreversible damage of dental pulp cells by DM-induced oxidative stress. Davallialactone, a natural antioxidant, may be useful to treat complicated oral disease, representing an improvement for pulp vital therapy.

Davallialactone from Mushroom Reduced Premature Senescence and Inflammation on Glucose Oxidative Stress in Human Diploid Fibroblast Cells

Mushrooms are both food and a source of natural compounds of biopharmaceutical interest. The purpose of this study was to clarify whether davallialactone from mushroom extract affected the pathogenesis of hyperglycemia oxidative stress and the aging process in human diploid fibroblast (HDF) cells. The high-glucose state with glucose oxidase resulted in glucose oxidative stress, induction of inflammatory molecules, dysfunction of antioxidant molecules, and activation of mitogen-activated protein kinase (MAPKs) and its downstream signaling in old HDF cells. The exposure of glucose oxidative stress in middle-stage cells led to stress-induced premature senescence (SIPS) via senescence-associated β-galactosidase (SA β-gal) activity and displayed replicative senescence phenomena. However, davallialactone reduces the pathogenesis of glucose oxidative stress and the aging process through down-regulation of SA β-gal activity. These results strongly suggest that natural compounds, especially mushroom extract davallialactone, improve the pathogenesis of glucose oxidative stress and the aging process. Hence, davallialactone has potential in the treatment of diabetes mellitus or age-related disease complications.

Eukaryotic elongation factor 2 kinase regulates the development of hypertension through oxidative stress-dependent vascular inflammation

Eukaryotic elongation factor 2 kinase (eEF2K) is a Ca2+/calmodulin-dependent protein kinase. We recently demonstrated that eEF2K protein increases in mesenteric artery from spontaneously hypertensive rats (SHR). Pathogenesis of hypertension is regulated in part by vascular inflammation. We tested the hypothesis whether eEF2K mediates vascular inflammatory responses and development of hypertension. In vascular endothelial cells, small interfering RNA (siRNA) against eEF2K inhibited induction of VCAM-1 and endothelial-selectin as well as monocyte adhesion by TNF-α (10 ng/ml). eEF2K siRNA inhibited phosphorylation of JNK and NF-κB p65 as well as reactive oxygen species (ROS) production by TNF-α. In vascular smooth muscle cells, eEF2K siRNA also inhibited VCAM-1 induction and phosphorylation of JNK and NF-κB by TNF-α. In vivo, increased blood pressure in SHR and ROS production, induction of inflammatory molecules, and hypertrophy in SHR superior mesenteric artery were reduced by an eEF2K inhibitor NH125 (500 μg·kg(-1)·day(-1)). In SHR superior mesenteric artery, impairment of ACh-induced relaxation was normalized by NH125. The present results for the first time demonstrate that eEF2K mediates TNF-α-induced vascular inflammation via ROS-dependent mechanism, which is at least partly responsible for the development of hypertension in SHR.

Negative regulatory approaches to the attenuation of Toll-like receptor signaling

Toll-like receptors (TLRs) are pivotal components of the innate immune response, which is responsible for eradicating invading microorganisms through the induction of inflammatory molecules. These receptors are also involved in responding to harmful endogenous molecules and have crucial roles in the activation of the innate immune system and shaping the adaptive immune response. However, TLR signaling pathways must be tightly regulated because undue TLR stimulation may disrupt the fine balance between pro- and anti-inflammatory responses. Such disruptions may harm the host through the development of autoimmune and inflammatory diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Several studies have investigated the regulatory pathways of TLRs that are essential for modulating proinflammatory responses. These studies reported several pathways and molecules that act individually or in combination to regulate immune responses. In this review, we have summarized recent advancements in the elucidation of the negative regulation of TLR signaling. Moreover, this review covers the modulation of TLR signaling at multiple levels, including adaptor complex destabilization, phosphorylation and ubiquitin-mediated degradation of signal proteins, manipulation of other receptors, and transcriptional regulation. Lastly, synthetic inhibitors have also been briefly discussed to highlight negative regulatory approaches in the treatment of inflammatory diseases.

Sulfur mustard analog, 2-chloroethyl ethyl sulfide-induced skin injury involves DNA damage and induction of inflammatory mediators, in part via oxidative stress, in SKH-1 hairless mouse skin

Bifunctional alkyalating agent, sulfur mustard (SM)-induced cutaneous injury is characterized by inflammation and delayed blistering. Our recent studies demonstrated that 2-chloroethyl ethyl sulfide (CEES), a monofunctional analog of SM that can be used in laboratory settings, induces oxidative stress. This could be the major cause of the activation of Akt/MAP kinase and AP1/NF-κB pathways that are linked to the inflammation and microvesication, and histopathological alterations in SKH-1 hairless mouse skin. To further establish a link between CEES-induced DNA damage and signaling pathways and inflammatory responses, skin samples from mice exposed to 2 mg or 4 mg CEES for 9–48 h were subjected to molecular analysis. Our results show a strong CEES-induced phosphorylation of H2A.X and an increase in cyclooxygenase-2 (COX-2), inducible NOS (iNOS), and matrix metalloproteinase-9 (MMP-9) levels, indicating the involvement of DNA damage and inflammation in CEES-induced skin injury in male and female mice. Since, our recent studies showed reduction in CEES-induced inflammatory responses by glutathione (GSH), we further assessed the role of oxidative stress in CEES-related DNA damage and the induction of inflammatory molecules. Oral GSH (300 mg/kg) administration 1 h before CEES exposure attenuated the increase in both CEES-induced H2A.X phosphorylation (59%) as well as expression of COX-2 (68%), iNOS (53%) and MMP-9 (54%). Collectively, our results indicate that CEES-induced skin injury involves DNA damage and an induction of inflammatory mediators, at least in part via oxidative stress. This study could help in identifying countermeasures that alone or in combination, can target the unveiled pathways for reducing skin injury in humans by SM.

Acquisition of Anergy to Proinflammatory Cytokines in Nonimmune Cells through Endoplasmic Reticulum Stress Response: A Mechanism for Subsidence of Inflammation

Acute endoplasmic reticulum (ER) stress causes induction of inflammatory molecules via activation of NF-kappaB. However, we found that, under ER stress conditions, renal mesangial cells acquire anergy to proinflammatory stimuli. Priming of the cells with ER stress inducers (tunicamycin, thapsigargin, A23187, and AB5 subtilase cytotoxin) caused blunted induction of MCP-1 in response to TNF-alpha, IL-1beta, macrophage-derived factors, or bystander macrophages. The magnitude of suppression was closely correlated with the level of GRP78, an endogenous indicator of ER stress. The suppression of MCP-1 under ER stress conditions was reversible and observed in general regardless of cell types or triggers of ER stress. The decrease in the level of MCP-1 mRNA was ascribed to transcriptional suppression via unexpected inhibition of NF-kappaB, but not to accelerated mRNA degradation. Subsequent experiments revealed that TNFR-associated factor 2, an essential component for TNF-alpha signaling, was down-regulated by ER stress. We also found that, under ER stress conditions, expression of NF-kappaB suppressor A20 was induced. Overexpression of A20 resulted in suppression of cytokine-triggered NF-kappaB activation and knockdown of A20 by RNA interference significantly attenuated induction of anergy by ER stress. In contrast, other ER stress-inducible/-related molecules that may suppress NF-kappaB (e.g., GRP78, NO, reactive oxygen species, and IkappaB) were not involved in the inhibitory effects of ER stress. These results elucidated ER stress-dependent mechanisms by which nonimmune cells acquire anergy to inflammatory stimuli under pathological situations. This self-defense machinery may play a role in halting progression of acute inflammation and in its spontaneous subsidence.

Serum amyloid A protein family. Differential induction by oxidized lipids in mouse strains.

During inflammation, serum amyloid A (SAA) protein increases up to 1000-fold and can become a major component of high-density lipoprotein (HDL). We have identified a new apolipoprotein molecule (SAA5) as a distinct member of the SAA family. It differs from the inflammatory isotypes (SAA1, SAA2, and SAA3) not only in structure but in the fact that it is constitutive on normal HDL where it accounts for more than 90% of total SAA. Whereas all members of the SAA family, including SAA5, responded to endotoxin administration, SAA5 contrasted with other SAAs in its resistance to induction either by a high-fat, high-cholesterol atherogenic diet or the injection of mildly oxidized LDL (MM-LDL). These data provide further evidence that the induction of inflammatory molecules by oxidized lipids is selective. In atherosclerosis-susceptible C57BL/6 mice and atherosclerosis-resistant C3H/HeJ mice, the inflammatory SAA isotypes (SAA1, SAA2, and SAA3) responded in a strain-specific manner to oxidized lipids either generated with feeding of the atherogenic diet or introduced by MM-LDL injection. We hypothesize that the constitutive SAA5 molecules on normal HDL may contribute to its normal physiological role and that the dramatic induction of the inflammatory SAA subfamily equips the particle for an altered yet related functional role appropriate to the inflammatory state.