Transcription Of Inflammatory Mediators Research Articles

Anti-inflammatory effect of a triterpenoid from Balanophora laxiflora: results of bioactivity-guided isolation

Balanophora laxiflora, a medicinal plant traditionally used to treat fever, pain, and inflammation in Vietnam, has been reported to possess prominent anti-inflammatory activity. This study examined the active constituents and molecular mechanisms underlying these anti-inflammatory effects using bioactivity-guided isolation in combination with cell-based assays and animal models of inflammation. Among the isolated compounds, the triterpenoid (21α)-22-hydroxyhopan-3-one (1) showed the most potent inhibitory effect on COX-2 expression in LPS-stimulated Raw 264.7 macrophages. Furthermore, 1 suppressed the expression of the inflammatory mediators iNOS, IL-1β, INFβ, and TNFα in activated Raw 264.7 macrophages and alleviated the inflammatory response in carrageenan-induced paw oedema and a cotton pellet-induced granuloma model. Mechanistically, the anti-inflammatory effects of 1 were mediated via decreasing cellular reactive oxygen species (ROS) levels by inhibiting NADPH oxidases (NOXs) and free radical scavenging activities. By downregulating ROS signalling, 1 reduced the activation of MAPK signalling pathways, leading to decreased AP-1-dependent transcription of inflammatory mediators. These findings shed light on the chemical constituents that contribute to the anti-inflammatory actions of B. laxiflora and suggest that 1 is a promising candidate for treating inflammation-related diseases.

1258-P: Il-1ß-Induced Transcription of Nf-kB Target Genes Is Repressed by Bet Bromodomain Inhibitors in Pancreatic ß-Cells

Autoimmune diabetes is characterized by chronic inflammation of pancreatic islets which ultimately destroys insulin-producing β-cells. In the islet, elevated proinflammatory cytokines lead to increased transcription of inducible nitric oxide synthase (iNOS) and its downstream product, nitric oxide (NO). Elevated levels of NO for prolonged periods lead to β-cell apoptosis. The exact causes of autoimmune diabetes are not well defined and, although genetic predisposition is a factor, low concordance rates of autoimmune diabetes among monozygotic twins indicates a role for epigenetic factors. Recent studies suggest that the bromodomain and extraterminal domain (BET) family of epigenetic regulatory proteins contribute to the onset and progression of autoimmune diabetes. BET proteins are epigenetic readers of sites of lysine acetylation found commonly on histones and have emerged as promising drug targets for a wide variety of diseases. We hypothesize that BET proteins increase proinflammatory cytokine-induced transcription in β-cells leading to β-cell damage and that selective inhibition of BET bromodomains with small molecules will prevent or reverse the progression of autoimmune diabetes. Here, we show that BET bromodomain inhibitors decrease the β-cell response to proinflammatory cytokines in an insulinoma β-cell line (INS832/13) and primary rat islets. BET inhibitors attenuated cytokine-induced transcription of inflammatory mediators, including iNOS. This decreased transcription is mediated through inhibition of the NF-κB signaling pathway by BET inhibitors. Using knockdown of individual BET proteins in a β-cell line, we identified the importance of individual BET family members in the altered transcriptional profile characteristic of autoimmune diabetes. This work uncovers important mechanisms of disease onset and progression of autoimmune diabetes, laying the groundwork for more targeted treatments with drug-like small molecules. Disclosure J. Nord: None. S. Wynia-smith: None. B. C. Smith: None. R. Jones lipinski: None. Funding American Diabetes Association (1-18-IBS-068 to B.C.S.); National Institutes of Health (R01DK119359, T32HL134643)

Gene Expression of Inhibitory Receptors and Immune Regulatory Molecules in Polarized Macrophages Derived from Early- and Late-Stage BD Patients

Background: Bipolar disorder (BD) has been associated with increased levels of peripheral inflammatory mediators and neuroinflammation. Previously, we observed different immune responses in macrophages of BD patients at different stages of the disorder. Thus, we aimed to further evaluate the regulation of immune response in BD by quantifying the expression of immune checkpoint receptors and respective ligands, as well as molecules involved in regulation and transcription of inflammatory mediators in polarized macrophages of early and late stages individuals with BD. Methods: qRT-PCR was performed to analyze the expression of TLR1, TLR6, PD-1, NFKB1, PD-L1, PD-L2 and TIM-3 in samples of proinflammatory M1 or M(IFNγ+LPS) and anti-inflammatory M2 or M(IL-4) macrophages derived from peripheral blood mononuclear cells (PBMCs) of euthymic BD patients (n=16), classified as early-stage BD (BD-E, n=9) and late-stage BD (BD-L, n=7) - according to Functional Assessment Short Test (FAST) - and healthy controls (HC, n=10). Results: M(IL-4) from BD-E showed higher expression levels of NFKB1 and PD-L1 in comparison to HC (p<0.05), while BD-L only had higher expression levels of PD-L1 compared to HC (p<0.05). No statistical differences were found between groups for the expression levels of TLR1, PD-L2 and TIM-3 in M(IL-4) phenotype, while expression levels remained unchanged in M(IFNγ+LPS) for all markers. TLR6 and PD-1 did not show PCR amplification in both macrophage phenotypes. Conclusion: Our findings suggest an immunological regulation acting as a compensatory mechanism by M2 anti-inflammatory macrophages at an early stage of BD, although decreased regulation in these cells seems to be observed at late stages of the disorder. We hypothesize that such alterations are possibly due to chronic low-grade inflammation during the course of BD, resulting in the ‘exhaustion’ of macrophage response. However, further investigation is required to comprehend better the role of immune regulatory mechanisms in the disorder. Funding Information: This work was supported by the FIPE-HCPA (Project Number 150396) and National Council for Scientific and Technological Development (CNPq, Brazil; Project Number PQ 302382/2019-4); and BA is a scholarship recipient from CNPq, Brazil. Declaration of Interests: None to declare. Ethics Approval Statement: All participants provided written informed consent before their inclusion, and this study was approved by the Institutional Review Board of Hospital de Clinicas de Porto Alegre (HCPA, Project Number 150396).

Microbubble formulation influences inflammatory response to focused ultrasound exposure in the brain

Focused ultrasound and microbubble (FUS + MB)-mediated blood–brain barrier (BBB) permeability enhancement can facilitate targeted brain-drug delivery. While controlling the magnitude of BBB permeability enhancement is necessary to limit tissue damage, little work has attempted to decouple these concepts. This work investigated the relationship between BBB permeability enhancement and the relative transcription of inflammatory mediators 4 h following sonication. Three microbubble formulations, Definity, BG8774, and MSB4, were compared, with the dose of each formulation normalized to gas volume. While changes in the transcription of key proinflammatory mediators, such as Il1b, Ccl2, and Tnf, were correlated to the magnitude of BBB permeability enhancement, these correlations were not independent of microbubble formulation; microbubble size distribution may play an important role, as linear regression analyses of BBB permeability magnitude versus differential gene expression for these proinflammatory mediators revealed significantly greater slopes for MSB4, a monodisperse microbubble with mean diameter of 4 μm, compared to Definity or BG8774, both polydisperse microbubbles with mean diameters below 2 μm. Additionally, the function of an acoustic feedback control algorithm, based on the detection threshold of ultraharmonic emissions, was assessed. While this control strategy was effective in limiting both wideband emissions and red blood cell extravasation, microbubble formulation was found to influence the magnitude of BBB leakage and correlations to acoustic emissions. This work demonstrates that while the initial magnitude of FUS + MB-mediated BBB permeability enhancement has a clear influence on the subsequent inflammatory responses, microbubble characteristics influence these relationships and must also be considered.

2117-P: BET Bromodomain Inhibitors Mitigate Cytokine-Induced Transcription in ß-Cells via Inhibition of Nf-κB

Type 1 diabetes is an autoimmune disease characterized by chronic inflammation of pancreatic islets, mediated by proinflammatory cytokines, leading to reduced response to glucose and ultimately selective destruction of insulin-producing β-cells. In common with many autoimmune diseases, the exact causes are poorly understood. Although genetic predisposition is a factor, low concordance rates of autoimmune diabetes among monozygotic twins suggest an, as yet undetermined, contribution of epigenetic factors. Recent studies have begun to explore the contributions of epigenetic regulatory proteins in onset and progression of autoimmune diabetes. An important class of epigenetic “readers” is the bromodomain and extraterminal domain (BET) family (Brd2, Brd3, Brd4, and Brdt), which has emerged as promising drug targets for a wide variety of diseases. A unique trait of the BET family is that these proteins contain two bromodomains (BD1 and BD2) that afford them the capacity to simultaneously bind two acetylated histones and/or non-histone proteins such as DNA-binding factors to modulate transcription in a cell-type specific manner. Here, we use an insulinoma β-cell line (INS832/13) and primary rat islets to investigate the ability of chemical inhibitors of BET bromodomain proteins to decrease the β-cell response to proinflammatory cytokines. We found that BET inhibitors mitigated cytokine-induced transcription of inflammatory mediators known to damage β-cells. This is mediated through the inhibition of the NF-κB pathway by BET inhibitors. Furthermore, using CRISPR/Cas9 knockout insulinoma β-cell lines of Brd2, Brd3, and Brd4 and BD1 vs. BD2 specific chemical inhibitors, we identified key mechanisms through which this altered transcriptional profile occurs. This work provides important mechanistic insights to disease onset and progression of autoimmune diabetes for which current therapies are ineffective. Disclosure J. Nord: None. S. Wynia-Smith: None. B.C. Smith: None. Funding American Diabetes Association (1-18-IBS-068 to B.C.S.); National Institute of Diabetes and Digestive and Kidney Diseases (R01DK119359)

NOD Signaling and Cell Death.

Innate immune signaling and programmed cell death are intimately linked, and many signaling pathways can regulate and induce both, transcription of inflammatory mediators or autonomous cell death. The best-characterized examples for these dual outcomes are members of the TNF superfamily, the inflammasome receptors, and the toll-like receptors. Signaling via the intracellular peptidoglycan receptors NOD1 and NOD2, however, does not appear to follow this trend, despite involving signaling proteins, or proteins with domains that are linked to programmed cell death, such as RIP kinases, inhibitors of apoptosis (IAP) proteins or the CARD domains on NOD1/2. To better understand the connections between NOD signaling and cell death induction, we here review the latest findings on the molecular regulation of signaling downstream of the NOD receptors and explore the links between this immune signaling pathway and the regulation of cell death.

2182Sirtuin 5 regulates arterial thrombosis by modulating endothelial plasminogen activator inhibitor-1

Abstract Introduction Arterial thrombosis as a result of plaque rupture or erosion is a crucial event in myocardial infarction and stroke. Oxidative stress and inflammation promote endothelial dysfunction and play a pivotal role in destabilization of the atherosclerotic plaque. Sirtuin 5 (SIRT5) is a member of the sirtuin protein family with function as a NAD+-dependent protein desuccinylase and demalonylase. Being implicated in the regulation of different pathophysiological processes among which production of reactive oxygen species and transcription of inflammatory mediators, SIRT5 plays a role in the development of several cardiovascular diseases such as myocardial infarction and stroke. To date, the possible involvement of SIRT5 as a mediator of arterial thrombosis remains to be investigated. Purpose In this study we investigate the putative role of this protein in arterial thrombosis by using an established in vivo mouse model. The translational value of animal findings as well as the molecular mechanism underlying the observed effect will be investigated also in primary human aortic endothelial cells (HAECs). Methods SIRT5 knockout (KO) as well as SIRT5 transgenic (TG) animals were used for in vivo experiments. HAECs treated with SIRT5 silencing RNA (si-SIRT5) and stimulated with tumor necrosis factor (TNF)-α were used for in vitro assays. Results When compared to WT animals, SIRT5 KO mice display blunted carotid artery thrombus formation as underlined by delayed time to occlusion in a photochemical injury model. Oppositely, in SIRT5 TG mice the formation of an occlusive thrombus is accelerated (Fig 1). Mechanistically, SIRT5 KO and WT animals show no difference in terms of vascular tissue factor (TF) activity, TF concentration in plasma and expression of TF pathway inhibitor (TFPI) in the aorta. In line with the observed reduced thrombogenicity, SIRT5 KO animal express reduced level of the pro-thrombotic plasminogen activator-1 (PAI-1), as assessed by western blot in aorta lysate. Of interest, SIRT5 genetic deletion does not affect platelet aggregation, as assessed by ex-vivo collagen-induced aggregometry. In HAECs, SIRT5-silencing inhibits PAI-1 expression in response to TNF-α. Real-time polymerase chain reaction revealed that inhibition of PAI-1 expression occurs at the mRNA level. This effect is mediated by reduced activation of the MAP kinase Erk 1/2, but not JNK (Fig 1). Conclusions SIRT5 mediates arterial thrombosis by increasing endothelial PAI-1 expression. Hence, SIRT5 may be an effective therapeutic target in the context of atherothrombosis.

Equol, a Dietary Daidzein Gut Metabolite Attenuates Microglial Activation and Potentiates Neuroprotection In Vitro.

Estrogen deficiency has been well characterized in inflammatory disorders including neuroinflammation. Daidzein, a dietary alternative phytoestrogen found in soy (Glycine max) as primary isoflavones, possess anti-inflammatory activity, but the effect of its active metabolite Equol (7-hydroxy-3-(4′-hydroxyphenyl)-chroman) has not been well established. In this study, we investigated the anti-neuroinflammatory and neuroprotective effect of Equol in vitro. To evaluate the potential effects of Equol, three major types of central nervous system (CNS) cells, including microglia (BV-2), astrocytes (C6), and neurons (N2a), were used. Effects of Equol on the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), Mitogen activated protein kinase (MAPK) signaling proteins, and apoptosis-related proteins were measured by western blot analysis. Equol inhibited the lipopolysaccharide (LPS)-induced TLR4 activation, MAPK activation, NF-kB-mediated transcription of inflammatory mediators, production of nitric oxide (NO), release of prostaglandin E2 (PGE-2), secretion of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), in Lipopolysaccharide (LPS)-activated murine microglia cells. Additionally, Equol protects neurons from neuroinflammatory injury mediated by LPS-activated microglia through downregulation of neuronal apoptosis, increased neurite outgrowth in N2a cell and neurotrophins like nerve growth factor (NGF) production through astrocytes further supporting its neuroprotective potential. These findings provide novel insight into the anti-neuroinflammatory effects of Equol on microglial cells, which may have clinical significance in cases of neurodegeneration.

Kinetics of chemotaxis, cytokine, and chemokine release of NR8383 macrophages after exposure to inflammatory and inert granular insoluble particles

Accumulation of macrophages and neutrophil granulocytes in the lung are key events in the inflammatory response to inhaled particles. The present study aims at the time course of chemotaxis in vitro in response to the challenge of various biopersistent particles and its functional relation to the transcription of inflammatory mediators.NR8383 rat alveolar macrophages were challenged with particles of coarse quartz, barium sulfate, and nanosized silica for one, four, and 16h and with coarse and nanosized titanium dioxide particles (rutile and anatase) for 16h only. The cell supernatants were used to investigate the chemotaxis of unexposed NR8383 macrophages. The transcription of inflammatory mediators in cells exposed to quartz, silica, and barium sulfate was analyzed by quantitative real-time PCR.Challenge with quartz, silica, and rutile particles induced significant chemotaxis of unexposed NR8383 macrophages. Chemotaxis caused by quartz and silica was accompanied by an elevated transcription of CCL3, CCL4, CXCL1, CXCL3, and TNFα. Quartz exposure showed an earlier onset of both effects compared to the nanosized silica. The strength of this response roughly paralleled the cytotoxic effects. Barium sulfate and anatase did not induce chemotaxis and barium sulfate as well caused no elevated transcription.In conclusion, NR8383 macrophages respond to the challenge with inflammatory particles with the release of chemotactic compounds that act on unexposed macrophages. The kinetics of the response differs between the various particles.

Temperature-induced transcription of inflammatory mediators and the influence of HSP70 following LPS stimulation of southern bluefin tuna leukocytes

Temperature-induced transcription of inflammatory mediators and the influence of HSP70 following LPS stimulation of southern bluefin tuna leukocytes

Supramolecular polymer micelles self-assembled from α-cyclodextrin and PLLA–PCL based copolymers

Accumulation of macrophages and neutrophil granulocytes in the lung are key events in the inflammatory response to inhaled particles. The present study aims at the time course of chemotaxis in vitro in response to the challenge of various biopersistent particles and its functional relation to the transcription of inflammatory mediators.NR8383 rat alveolar macrophages were challenged with particles of coarse quartz, barium sulfate, and nanosized silica for one, four, and 16 h and with coarse and nanosized titanium dioxide particles (rutile and anatase) for 16 h only. The cell supernatants were used to investigate the chemotaxis of unexposed NR8383 macrophages. The transcription of inflammatory mediators in cells exposed to quartz, silica, and barium sulfate was analyzed by quantitative real-time PCR.Challenge with quartz, silica, and rutile particles induced significant chemotaxis of unexposed NR8383 macrophages. Chemotaxis caused by quartz and silica was accompanied by an elevated transcription of CCL3, CCL4, CXCL1, CXCL3, and TNFα. Quartz exposure showed an earlier onset of both effects compared to the nanosized silica. The strength of this response roughly paralleled the cytotoxic effects. Barium sulfate and anatase did not induce chemotaxis and barium sulfate as well caused no elevated transcription.In conclusion, NR8383 macrophages respond to the challenge with inflammatory particles with the release of chemotactic compounds that act on unexposed macrophages. The kinetics of the response differs between the various particles.

Vasoactive intestinal peptide protects against β‐amyloid‐induced neurodegeneration by inhibiting microglia activation at multiple levels

Alzheimer's disease (AD) is characterized by extracellular deposits of fibrillar beta-amyloid (Abeta) in the brain, increased microglial-mediated inflammatory reactions in senile plaques, selective neuronal death, and cognitive deficits. The use of agents that limit microglial activation and inflammation in AD has recently emerged as an attractive therapeutic strategy for this disease. The vasoactive intestinal peptide (VIP), a widely distributed neuropeptide, has shown neuroprotective effects in acute brain damage in vivo and potent anti-inflammatory actions in central nervous system. Here, we report that VIP inhibits Abeta-induced neurodegeneration by indirectly inhibiting the production of a wide panel of inflammatory and neurotoxic agents by activated microglia cells. The inhibitory effect of VIP is mediated by blocking signaling through the p38 MAPK, p42/p44 MAPK, and NFkB cascades, the three major transduction pathways involved in the transcription of inflammatory mediators and the production of free radicals by Abeta-activated microglia cells. Based on its neuroprotective action and its efficacy in inhibiting a broad range of inflammatory responses, VIP may provide a novel therapeutic approach to AD.

Systemic inflammation-associated glucocorticoid resistance and outcome of ARDS.

Dysregulated systemic inflammation with excess activation of pro-inflammatory transcription factor nuclear factor-kappaB (NF-kappaB)-activated by inflammatory signals-compared to the anti-inflammatory transcription factor glucocorticoid receptor-alpha (GRalpha)-activated by endogenous or exogenous glucocorticoids (GCs)-is an important pathogenetic mechanism for pulmonary and extrapulmonary organ dysfunction in patients with acute respiratory distress syndrome (ARDS). Activation of one transcription factor in excess of the binding (inhibitory) capacity of the other shifts cellular responses toward increased (dysregulated) or decreased (regulated) transcription of inflammatory mediators over time. Recent data indicate that failure to improve in ARDS (unresolving ARDS) is frequently associated with failure of the activated GRs to downregulate the transcription of inflammatory cytokines despite elevated levels of circulating cortisol, a condition defined as systemic inflammation-associated acquired GC resistance; it is potentially reversible with prolonged GC supplementation. In the first part of this paper, after a brief description of inflammation in ARDS and our model of translational research, we review the two cellular signaling pathways that are central to the regulation of inflammation-the stimulatory NF-alphaB and the inhibitory GRalpha. In the second part, we review findings of recent studies indicating that excessive inflammatory activity in patients with unresolving ARDS may induce noncompensated GC resistance in target organs. In the third part, we review factors affecting cellular response to GC and potential mechanisms involved in inflammation-associated GC resistance.