IL-1β Synthesis Research Articles

Role of caspase-11 non-canonical inflammasomes in retinal ischemia/reperfusion injury

BackgroundRetinal ischemia/reperfusion (IR) injury is a common pathological process in many ophthalmic diseases. Interleukin-1β (IL-1β) is an important inflammatory factor involved in the pathology of retinal IR injury, but the mechanism by which IL-1β is regulated in such injury remains unclear. Caspase-11 non-canonical inflammasomes can regulate the synthesis and secretion of IL-1β, but its role in retinal IR injury has not been elucidated. This study aimed to evaluate the role of caspase-11 non-canonical inflammasomes in retinal IR injury.MethodsRetinal IR injury was induced in C57BL/6J mice by increasing the intraocular pressure to 110 mmHg for 60 min. The post-injury changes in retinal morphology and function and in IL-1β expression were compared between caspase-11 gene knockout (caspase-11−/−) mice and wild-type (WT) mice. Morphological and functional changes were evaluated using hematoxylin–eosin staining and retinal whole mount staining and using electroretinography (ERG), respectively. IL-1β expression in the retina was measured using enzyme-linked immunosorbent assay (ELISA). The levels of caspase-11-related protein were measured using western blot analysis. The location of caspase-11 in the retina was determined via immunofluorescence staining. Mouse type I astrocytes C8-D1A cells were used to validate the effects of caspase-11 simulation via hypoxia in vitro. Small-interfering RNA targeting caspase-11 was constructed. Cell viability was evaluated using the MTT assay. IL-1β expression in supernatant and cell lysate was measured using ELISA. The levels of caspase-11-related protein were measured using western blot analysis.ResultsRetinal ganglion cell death and retinal edema were more ameliorated, and the ERG b-wave amplitude was better after retinal IR injury in caspase-11−/− mice than in WT mice. Further, caspase-11−/− mice showed lower protein expressions of IL-1β, cleaved caspase-1, and gasdermin D (GSDMD) in the retina after retinal IR injury. Caspase-11 protein was expressed in retinal glial cells, and caspase-11 knockdown played a protective role against hypoxia in C8-D1A cells. The expression levels of IL-1β, cleaved caspase-1, and GSDMD were inhibited after hypoxia in the si-caspase-11 constructed cells.ConclusionsRetinal IR injury activates caspase-11 non-canonical inflammasomes in glial cells of the retina. This results in increased protein levels of GSDMD and IL-1β and leads to damage in the inner layer of the retina.

IL-1β Induces Human Endothelial Surface Expression of IL-15 by Relieving let-7c-3p Suppression of Protein Translation.

Expression of IL-15 on the surface of human graft endothelial cells (ECs) bound to the IL-15Rα subunit can increase the activation of CTLs, potentiating allograft rejection. Our previous work showed that surface expression of this protein complex could be induced by alloantibody-mediated complement activation through increased IL-1β synthesis, secretion, and autocrine/paracrine IL-1-mediated activation of NF-κB. In this article, we report that cultured human ECs express eight differently spliced IL-15 transcripts. Remarkably, IL-1β does not alter the expression level of any IL-15 transcript but induces surface expression independently of RNA polymerase II-mediated transcription while requiring new protein translation. Mechanistically, IL-1β causes an NF-κB-mediated reduction in the level of microRNA Let-7c-3p, thereby relieving a block of translation of IL-15 surface protein. Let7c-3p anti-miR can induce EC surface expression of IL-15/IL-15Rα in the absence of complement activation or of IL-1, enabling IL-15 transpresentation to boost CD8 T cell activation. Because of the complexity we have uncovered in IL-15 regulation, we recommend caution in interpreting increased total IL-15 mRNA or protein levels as a surrogate for transpresentation.

Minthostachys verticillata essential oil modulates cytokine synthesis and Staphylococcus aureus internalization in MAC-T cells at least through TLR4/MyD88/NFkB pathway.

The aim of this study was to evaluate the activation pathway(s) triggered by Minthostachys verticillata essential oil (EO) in bovine mammary epithelial cells (MAC-T) challenged with a strain of bovine Staphylococcus aureus. MAC-T cells were stimulated with EO, S. aureus or pre-treated with EO and then challenged with S. aureus. Cytokine's release was measured by ELISA. The mRNA for TLR2, TLR4, NOD2, MyD88 and NFκB was quantified by RT-qPCR. S. aureus adherence and internalization was also evaluated. MAC-T cells stimulated with S. aureus synthesized high levels of IL-1ß and IL-6 were kept up to 48 h, while IL-4 levels were not altered.Cells pre-treated with EO for 2 and 6h and then challenged with S. aureus showed a significant increase of IL-1β and IL-6. However, in these cells, a decrease in IL-1ß and IL-6 levels and an increase of IL-4 values was observed from 24 h. No significant increase in the expression levels of TLR2 or NOD2 was detected in all stimulated cells. However, the expression of TLR4, MyD88 and NFκB was increased in cells stimulated with S. aureus at 2 and 6 h as well as in cells pre-treated with EO between 2 and 6h and then challenged with S. aureus. The NFκB expression levels was similar to control at 24h in all stimulated cells, although pro-inflammatory cytokine levels and TLR4 and MyD88 expression levels remained high in cells stimulated with S. aureus. This results suggested the activation of other pathways independent of MyD88 by the pathogen that involucrated the activation of others transcription factors. Pre-treatment with EO during 2, 6 and 24h did not affect S. aureus adherence but decreased its internalization. In conclusion, pre-treatment with EO increased the IL-1β and IL-6 synthesis during the first hours post-challenged with S. aureus up-regulating TLR4/MyD88/NFκB pathway. Furthermore, EO increased the IL-4 levels from 6 to 24 h down-regulating the NFκB and possibly other transcription factors activated by the pathogen, which decreased its internalization into MAC-T cells.

Assessment of Modulating Effect of the Experimental Drug Astrabionorm on Synthesis of Proinflammatory Cytokine IL-1β and Anti-Inflammatory Cytokine IL-10 in the Splenic Red Pulp Cells in a Mouse Model of Sepsis.

An indirect immunohistochemical method was used to study the production of proinflammatory (IL-1β) and anti-inflammatory (IL-10) cytokines in the spleen cells of mature male C57BL/6 mice with an experimental model of sepsis and during treatment with a drug based on formic acid aldehyde (Astrabionorm). Clinical isolates of two strains of Pseudomonas aeruginosa were used. In the red pulp of the spleen, interleukin-positive cells represented by mononuclear forms were identified, as well as differences in the intensity of immunohistochemical staining of these cells for the studied interleukins in the two models used. A modulating role of the drug in the production of interleukins by the splenic red pulp cells during sepsis is assumed.

Inhibition of NF-κB and ERK signaling pathways in osteoclasts and M1 macrophage polarization: Mechanistic insights into the anti-osteoporotic effects of Pseudolaric acid B

Osteoporosis, characterized by bone metabolism disruption leading to gradual bone loss and increased fracture susceptibility, is linked to the excessive activation of osteoclasts. Pseudolaric acid B (PAB), identified as an NF-κB signaling inhibitor crucial for osteoclastogenesis, is explored here for its protective effects in osteoporosis. Noncytotoxic PAB's impact on osteoclast differentiation was assessed through cell viability and osteoclast formation assays, with subsequent testing of osteoclast function via bone resorption assays. Quantitative real-time polymerase chain reaction evaluated PAB's genetic-level impact on osteoclastogenesis. Network pharmacology, western blot, and luciferase reporter gene assays were employed to elucidate PAB's regulatory mechanism. In an in vivo model of osteoporosis induced by ovariectomy (OVX) in mice, micro-CT, H&E staining, and TRAP staining facilitated histomorphometry analysis, while flow cytometry verified macrophage polarization. PAB demonstrated inhibitory effects on osteoclast formation and bone resorption in BMM and RAW264.7 cells, suppressing osteoclast-specific genes. Bioinformatic analysis, western blot, and luciferase assay results indicated PAB's inhibition of IκBα phosphorylation in the NF-κB signaling pathway and ERK in MAPKs, elucidating its mechanism. In vivo experiments confirmed PAB's attenuation of osteoporosis by reducing osteoclast formation in OVX mice. PAB further facilitated macrophage conversion from M1 to M2 and suppressed IL-1β, TNF-α, and IL-6 synthesis. In conclusion, PAB prevents osteoporosis by inhibiting RANKL-induced osteoclastogenesis through NF-κB and ERK signaling pathway suppression, coupled with macrophage polarization. These findings indicate the potential therapeutic role of PAB in osteoporosis.

FGF23 facilitates IL-1β synthesis in rheumatoid arthritis through activating PI3K, Akt, and NF-κB pathways.

Rheumatoid arthritis (RA) is a well-known autoimmune disorder related with joint pain, joint swelling, cartilage and bone degradation as well as deformity. Fibroblast growth factor 23 (FGF23) is an endocrine factor of the FGF family primarily produced by osteocytes and osteoblasts, involves an essential effect in pathogenesis of RA. IL-1β is a vital proinflammatory factor in the development of RA. However, the role of FGF23 on IL-1β synthesis in RA has not been fully explored. Our analysis of database revealed higher levels of FGF23 and IL-1β in RA samples compared with healthy controls. High-throughput screening demonstrated that IL-1β is a potential candidate factor after FGF23 treatment in RA synovial fibroblasts (RASFs). FGF23 concentration dependently promotes IL-1β synthesis in RASFs. FGF23 enhances IL-1β expression by activating the PI3K, Akt, and NF-κB pathways. Our findings support the notion that FGF23 is a promising target in the remedy of RA.

Glutamine and Arginine Combination for Sepsis Patients: Is It A Choice?

Sepsis is a life-threatening condition associated with a dysregulated host response to infection. It has indicated the serious stage of patient condition. Sepsis definition not only as a process of immune disorder or response of systemic inflammation, but also includes the alteration of multiple organs function, hence the existence of sepsis means the prolonged stays in the hospital or even the intensive care unit (ICU). Prevalence of hospital deaths caused by sepsis has been increasing as 90% since last 20 years. Sepsis and inflammation cause multiple organ dysfunction syndrome (MODS) which is usually the cause for death in intensive care units. To maintain the condition of those patients, an adequate nutrition supplementation is a must to be given. Several micro and macro nutrients have considered as immuno-nutrient, which can stimulate the immune condition of the patients. The roles of immune-nutrient are to repair barrier and immune function, improve wound healing, and decrease hyper inflammation. Glutamine and arginine are two nutrients which are suggested to treat the patient with sepsis. Decreasing or inhibiting stress response with substrates like glutamine and arginine may help preventing from MODS thus mortality in critically ill patients. Glutamine and Arginine independently have role on growth, tissue recovery, regeneration cell and reduce bacteria translocation in sepsis patient. However, the recent studies showed that glutamine and arginine combination (GAC) supplementation significantly decreased pro-inflammatory cytokine such as CRP, TNF-α, IL-1β, and IL-6, tissue repair, cell renewal and collagen synthesis. Several studies found that supplementation of glutamine and arginine combination has advantage effects on preventing sepsis, but the specific benefits remain unknown. This paper aims to provide an overview of the benefits of using glutamine and arginine as supplementation therapy in sepsis patients.

ZNF70 regulates IL-1β secretion of macrophages to promote the proliferation of HCT116 cells via activation of NLRP3 inflammasome and STAT3 pathway in colitis-associated colorectal cancer

Chronic inflammation is a key driver for colitis-associated colorectal cancer (CAC). It has been reported that inflammatory cytokines, such as IL-1β, could promote CAC. Zinc finger protein 70 (ZNF70) is involved in multiple biological processes. Here, we identified a previously unknown role for ZNF70 regulates macrophages IL-1β secretion to promote HCT116 proliferation in CAC, and investigated its underlying mechanism. We showed ZNF70 is much higher expressed in CAC tumor tissues compared with adjacent normal tissues in clinical CAC samples. Further experiments showed ZNF70 promoted macrophages IL-1β secretion and HCT116 proliferation. In LPS/ATP-stimulated THP-1 cells, we found ZNF70 activated NLRP3 inflammasome, resulting in robust IL-1β secretion. Interestingly, we discovered the ZnF domain of ZNF70 could interact with NLRP3 and decrease the K48-linked ubiquitination of NLRP3. Moreover, ZNF70 could activate STAT3, thereby promoting IL-1β synthesis. Noteworthy, ZNF70 enhanced proliferation by upregulating STAT3 activation in HCT116 cells cultured in the conditioned medium of THP-1 macrophages treated with LPS/ATP. Finally, the vivo observations were confirmed using AAV-mediated ZNF70 knockdown, which improved colitis-associated colorectal cancer in the AOM/DSS model. The correlation between ZNF70 expression and overall survival/IL-1β expression in colorectal cancer was verified by TCGA database. Taken together, ZNF70 regulates macrophages IL-1β secretion to promote the HCT116 cells proliferation via activation of NLRP3 inflammasome and STAT3 pathway, suggesting that ZNF70 may be a promising preventive target for treating in CAC.

A Mechanism of Action of Metformin in the Brain: Prevention of Methylglyoxal-Induced Glutamatergic Impairment in Acute Hippocampal Slices.

Metformin, a biguanide compound (N-1,1-dimethylbiguanide), is widely prescribed for diabetes mellitus type 2 (T2D) treatment. It also presents a plethora of properties, such as anti-oxidant, anti-inflammatory, anti-apoptosis, anti-tumorigenic, and anti-AGE formation activity. However, the precise mechanism of action of metformin in the central nervous system (CNS) needs to be clarified. Herein, we investigated the neuroprotective role of metformin in acute hippocampal slices exposed to methylglyoxal (MG), a highly reactive dicarbonyl compound and a key molecule in T2D developmental pathophysiology. Metformin protected acute hippocampal slices from MG-induced glutamatergic neurotoxicity and neuroinflammation by reducing IL-1β synthesis and secretion and RAGE protein expression. The drug also improved astrocyte function, particularly with regard to the glutamatergic system, increasing glutamate uptake. Moreover, we observed a direct effect of metformin on glutamate transporters, where the compound prevented glycation, by facilitating enzymatic phosphorylation close to Lys residues, suggesting a new neuroprotective role of metformin via PKC ζ in preventing dysfunction in glutamatergic system induced by MG.

Chlorogenic acid: a review on its mechanisms of anti-inflammation, disease treatment, and related delivery systems.

Chlorogenic acid is a bioactive compound ubiquitously present in the natural realm, lauded for its salient anti-inflammatory and antioxidant attributes. It executes its anti-inflammatory function by moderating the synthesis and secretion of inflammatory mediators, namely, TNF-α, IL-1β, IL-6, IL-8, NO, and PGE2. Concurrently, it modulates key signaling pathways and associated factors, including NF-κB, MAPK, Nrf2, and others, bestowing protection upon cells and tissues against afflictions such as cardio-cerebrovascular and diabetes mellitus. Nevertheless, the inherent low bioavailability of chlorogenic acid poses challenges in practical deployments. To surmount this limitation, sophisticated delivery systems, encompassing liposomes, micelles, and nanoparticles, have been devised, accentuating their stability, release mechanisms, and bioactivity. Given its innate anti-inflammatory prowess and safety profile, chlorogenic acid stands as a promising contender for advanced biomedical investigations and translational clinical endeavors.

The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19.

Thymalin is an immunomodulatory drug containing a polypeptide extract of thymus that has demonstrated efficacy in the therapy of acute respiratory distress syndrome and chronic obstructive pulmonary disease, as well as in complex therapy related to severe COVID-19 in middle-aged and elderly patients.. KE and EW dipeptides are active substances of Thymalin. There is evidence that KE stimulates cellular immunity and nonspecific resistance in organisms, exerting an activating effect on macrophages, blood lymphocytes, thymocytes, and neutrophils, while EW reduces angiotensin-induced vasoconstriction and preserves endothelium-dependent vascular relaxation by inhibiting ACE2, the target protein of SARS-CoV-2. However, the mechanism of the immunomodulatory action of Thymalin, KE, and EW during COVID-19 remains unclear. To identify the potential mechanism of action underlying the immunomodulatory activity of Thymalin and its active components, EW and KE dipeptides, we assessed inflammatory response in the context of COVID-19. Interactions between EW and KE dipeptides and double-stranded DNA (dsDNA) were investigated by molecular modeling and docking using ICM-Pro. Analysis of the possible effect of EW and KE dipeptides on gene expression and protein synthesis involved in the pathogenesis of COVID-19 was conducted through the use of bioinformatics methods, including a search for promoter sequences in the Eukaryotic Promoter Database, the determination of genes associated with the development of COVID-19 using the PathCards database of human biological pathways (pathway unification database), identification of the relationship between proteins through cluster analysis in the STRING database ('Search Tool for Retrieval of Interacting Genes/Proteins'), and assessment of the functional enrichment of protein-protein interaction (PPI) using the terms of gene ontology (GO) and the Markov cluster algorithm (MCL). After that, in vitro studying of a lipopolysaccharide (LPS)-induced model of inflammation using human peripheral blood mononuclear cells was performed. ELISA was applied to assess the level of cytokines (IL-1β, IL-6, TNFα) in the supernatant of cells with or without the impact of EW and KE peptides. Blood samples were obtained from four donors; for each cytokine, ELISA was performed 2-4 times, with two parallel experimental or control samples for each experiment (experiments to assess the effects of peptides on LPS-stimulated cells were repeated four times, while additional experiments with unstimulated cells were performed two times). Using molecular docking, GGAG was found to be the best dsDNA sequence in the classical B-form for binding the EW dipeptide, while GCGC is the preferred dsDNA sequence in the curved nucleosomal form for the KE dipeptide. Cluster analysis revealed that potential target genes for the EW and KE peptides encode the AKT1 and AKT2 proteins involved in the development of the cytokine storm. The specific targets for the EW peptide are the ACE2 and CYSLTR1 genes, and specific target for the KE peptide is the CHUK gene. Protein products of the ACE2, CYSLTR1, and CHUK genes are functionally associated with IL-1β, IL-6, TNF-α, IL-4, and IL-10 cytokines. An in vitro model of an inflammatory reaction demonstrated that Thymalin and EW and KE dipeptides reduced the synthesis of IL-1β, IL-6, and TNF-α cytokines in human peripheral blood mononuclear cells by 1.4-6.0 times. The immunomodulatory effect of Thymalin under the inflammatory response conditions in COVID-19 is based on the potential ability of its active components, EW and KE dipeptides, to regulate protein synthesis involved in the development of the cytokine storm.

Genetic Downregulation of the Metabotropic Glutamate Receptor Type 5 Dampens the Reactive and Neurotoxic Phenotype of Adult ALS Astrocytes.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive degeneration of motor neurons (MNs). Astrocytes display a toxic phenotype in ALS, which results in MN damage. Glutamate (Glu)-mediated excitotoxicity and group I metabotropic glutamate receptors (mGluRs) play a pathological role in the disease progression. We previously demonstrated that in vivo genetic ablation or pharmacological modulation of mGluR5 reduced astrocyte activation and MN death, prolonged survival and ameliorated the clinical progression in the SOD1G93A mouse model of ALS. This study aimed to investigate in vitro the effects of mGluR5 downregulation on the reactive spinal cord astrocytes cultured from adult late symptomatic SOD1G93A mice. We observed that mGluR5 downregulation in SOD1G93A astrocytes diminished the cytosolic Ca2+ overload under resting conditions and after mGluR5 simulation and reduced the expression of the reactive glial markers GFAP, S100β and vimentin. In vitro exposure to an anti-mGluR5 antisense oligonucleotide or to the negative allosteric modulator CTEP also ameliorated the altered reactive astrocyte phenotype. Downregulating mGluR5 in SOD1G93A mice reduced the synthesis and release of the pro-inflammatory cytokines IL-1β, IL-6 and TNF-α and ameliorated the cellular bioenergetic profile by improving the diminished oxygen consumption and ATP synthesis and by lowering the excessive lactate dehydrogenase activity. Most relevantly, mGluR5 downregulation hampered the neurotoxicity of SOD1G93A astrocytes co-cultured with spinal cord MNs. We conclude that selective reduction in mGluR5 expression in SOD1G93A astrocytes positively modulates the astrocyte reactive phenotype and neurotoxicity towards MNs, further supporting mGluR5 as a promising therapeutic target in ALS.

Human metapneumovirus driven IFN-β production antagonizes macrophage transcriptional induction of IL1-β in response to bacterial pathogens.

Human metapneumovirus (HMPV) is a pneumovirus that may cause severe respiratory disease in humans. HMPV infection has been found to increase susceptibility to bacterial superinfections leading to increased morbidity and mortality. The molecular mechanisms underlying HMPV-mediated increase in bacterial susceptibility are poorly understood and largely understudied. Type I interferons (IFNs), while critical for antiviral defenses, may often have detrimental effects by skewing the host immune response and cytokine output of immune cells. It is currently unknown if HMPV skews the inflammatory response in human macrophages triggered by bacterial stimuli. Here we report that HMPV pre-infection impacts production of specific cytokines. HMPV strongly suppresses IL-1β transcription in response to LPS or heat-killed Pseudomonas aeruginosa and Streptococcus pneumonia, while enhancing mRNA levels of IL-6, TNF-α and IFN-β. We demonstrate that in human macrophages the HMPV-mediated suppression of IL-1β transcription requires TANK-binding kinase 1 (TBK1) and signaling via the IFN-β-IFNAR axis. Interestingly, our results show that HMPV pre-infection did not impair the LPS-stimulated activation of NF-κB and HIF-1α, transcription factors that stimulate IL-1β mRNA synthesis in human cells. Furthermore, we determined that sequential HMPV-LPS treatment resulted in accumulation of the repressive epigenetic mark H3K27me3 at the IL1B promoter. Thus, for the first time we present data revealing the molecular mechanisms by which HMPV shapes the cytokine output of human macrophages exposed to bacterial pathogens/LPS, which appears to be dependent on epigenetic reprogramming at the IL1B promoter leading to reduced synthesis of IL-1β. These results may improve current understanding of the role of type I IFNs in respiratory disease mediated not only by HMPV, but also by other respiratory viruses that are associated with superinfections.

Activation of Inflammasome during Bluetongue Virus Infection.

Bluetongue virus (BTV), a double-stranded RNA virus belonging to the Sedoreoviridae family, provokes an economically important disease in ruminants. In this study, we show that the production of activated caspase-1 and interleukin 1 beta (IL-1β) is induced in BTV-infected cells. This response seems to require virus replication since a UV-inactivated virus is unable to activate this pathway. In NLRP3-/- cells, BTV could not trigger further IL-1β synthesis, indicating that it occurs through NLRP3 inflammasome activation. Interestingly, we observed differential activation levels in bovine endothelial cells depending on the tissue origin. In particular, inflammasome activation was stronger in umbilical cord cells, suggesting that these cells are more prone to induce the inflammasome upon BTV infection. Finally, the strength of the inflammasome activation also depends on the BTV strain, which points to the importance of viral origin in inflammasome modulation. This work reports the crucial role of BTV in the activation of the NLRP3 inflammasome and further shows that this activation relies on BTV replication, strains, and cell types, thus providing new insights into BTV pathogenesis.

Modulation of murine lupus by Aconitate Decarboxylase 1

Abstract Mitochondrial synthesis of itaconate by myeloid cells (monocytes and macrophages) is mediated by the TCA cycle enzyme Aconitate Decarboxylase 1 (Acod1). Upregulation of Acod1–itaconate pathway, occurs after activation of various Toll-like receptors (TLRs) or cytokine stimulation (TNF or type I Interferons). While various anti-inflammatory effects of the Acod1 – Itaconate pathway have been previously reported (e.g. decreases in IL-6 and IL-1β synthesis) the contribution of impairments in endogenous itaconate synthesis in systemic lupus erythematosus (SLE) remain poorly characterized. First, we explored and characterized Acod1 expression in bone marrow or monocyte-derived macrophages (BMDM and MDM, respectively) following in vitro imiquimod (IMQ) treatment. Then, we investigated the role of endogenous itaconate modulation in the development and severity of TLR-7 induced lupus using the IMQ model. 10-week-old wild type and Acod1 −/−mice were treated with topical IMQ cream for 5 weeks to induce an SLE phenotype. We found that Acod1 protein expression is induced in BMDM and MDM after 12 hours of IMQ stimulation, and this induction is partially dependent on IFNRa1 signaling. Moreover, Acod1 −/−BMDM treated with IMQ for 12 h displayed higher mRNA expression of il6, il1b, il18, ccl2, cxcl2, and cxcl9, together with an increase in pro-IL-1β protein levels. IL-6 and IL-1β production were also increased. After 5 weeks of in vivo IMQ topical treatment, Acod1 −/−mice have a higher concentration of circulating anti-dsDNA autoantibodies but a decrease in splenomegaly compared to the treated WT mice. These results, demonstrate a putative role for endogenous Acod1-itaconate pathway in the regulation of autoimmunity. This work is support by the NIH/NIAMS Intramural Research Program

Nitrogen-Containing Bisphosphonates Downregulate Cathepsin K and Upregulate Annexin V in Osteoclasts Cultured In Vitro.

Bisphosphonates are widely used in the treatment of osteoporosis; however, they are associated with the serious adverse event of bisphosphonate-related osteonecrosis of the jaw (BRONJ). The aim of this study is to assess the effects of nitrogen-containing bisphosphonates (N-PHs) on the synthesis of IL-1β, TNF-α, sRANKL, cathepsin K, and annexin V in bone cells cultured in vitro. Osteoblasts and bone marrow-derived osteoclasts were cultured in vitro, subjected to treatment with alendronate, risedronate, or ibandronate at a concentration of 10-5 M for 0 to 96 h and then assayed for IL-1β, sRANKL, and TNF-α production by ELISA. Cathepsin K and Annexin V-FITC staining in osteoclasts were assessed by flow cytometry. There was significant downregulation of IL-1β, sRANKL, and TNF-α in experimental osteoblasts compared to control cells, and there was upregulation of IL-1β and downregulation of RANKL and TNF-α in experimental osteoclasts. Furthermore, in osteoclasts, cathepsin K expression was downregulated at 48-72 h with alendronate treatment, while risedronate treatment resulted in upregulated annexin V expression at 48 h compared to the control treatment. Bisphosphonates added to bone cells inhibited osteoclastogenesis, which led to the downregulation of cathepsin K and induction of apoptosis in osteoclasts; these changes limited the capacity of bone remodelling and healing that may contribute to BRONJ induced by surgical dental procedures.

Brucella abortus induces mast cell activation through TLR-2 and TLR-4

The Gram-negative bacteria Brucella abortus is a major cause of brucellosis in animals and humans. The host innate immune response to B. abortus is mainly associated with phagocytic cells such as dendritic cells, neutrophils, and macrophages. However, as mast cells naturally reside in the main bacterial entry sites they may be involved in bacterial recognition. At present, little is known about the role of mast cells during B. abortus infection. The role of the innate immune receptors TLR2 and TLR4 in activation of mast cells by B. abortus (strain RB51) infection was analyzed in this study. The results showed that B. abortus did not induce mast cell degranulation, but did induce the synthesis of the cytokines IL-1β, IL-6, TNF-α, CCL3, CCL4, and CCL5. Furthermore, B. abortus stimulated key cell signaling molecules involved in mast cell activation such as p38 and NF-κB. Blockade of the receptors TLR2 and TLR4 decreased TNF-α and IL-6 release by mast cells in response to B. abortus. Taken together, our results demonstrate that mast cells are activated by B. abortus and may play a role in inducing an inflammatory response during the initial phase of the infection.

Alpinetin Suppresses Zika Virus-Induced Interleukin-1β Production and Secretion in Human Macrophages.

Zika virus (ZIKV) infection has been recognized to cause adverse sequelae in the developing fetus. Specially, this virus activates the excessive release of IL-1β causing inflammation and altered physiological functions in multiple organs. Although many attempts have been invested to develop vaccine, antiviral, and antibody therapies, development of agents focusing on limiting ZIKV-induced IL-1β release have not gained much attention. We aimed to study the effects of alpinetin (AP) on IL-1β production in human macrophage upon exposure to ZIKV. Our study demonstrated that ZIKV stimulated IL-1β release in the culture supernatant of ZIKV-infected cells, and AP could effectively reduce the level of this cytokine. AP exhibited no virucidal activities against ZIKV nor caused alteration in viral production. Instead, AP greatly inhibited intracellular IL-1β synthesis. Surprisingly, this compound did not inhibit ZIKV-induced activation of NF-κB and its nuclear translocation. However, AP could significantly inhibit ZIKV-induced p38 MAPK activation without affecting the phosphorylation status of ERK1/2 and JNK. These observations suggest the possibility that AP may reduce IL-1β production, in part, through suppressing p38 MAPK signaling. Our current study sheds light on the possibility of using AP as an alternative agent for treating complications caused by ZIKV infection-induced IL-1β secretion.

The activation of FPR3/PKA/Rap1/ERK1/2 and FPR3/p-IκB/NF-κB axis in fibroblasts promote capsular contracture after rhinoplasty

BackgroundCapsular contracture may occur after rhinoplasty due to rejection of silicone implants by the immune system. Our previous high-throughput sequencing of RNA in nasal capsular contracture tissue revealed that FPR3 was significantly increased in grade IV capsular contracture tissue, compared with grade II. ObjectiveThis study aimed to elucidate the effect and specific mechanism of FPR3 on capsular formation and contracture following rhinoplasty. MethodsUsing the GeneMANIA Database, the genes involved with FPR3 expression were searched, and the Gene Ontology analysis was performed to annotate the biological functions of the aforementioned genes. The mRNA and protein expressions of related genes in fibroblasts and capsular contracture tissues were analyzed using quantitative real-time PCR, western blot, and immunohistochemical staining. CCK-8 was used to determine the viability of cells. The migration capacity of fibroblasts was assessed using a wound healing assay. ELISA was used to detect levels of IL-1β, TNF-α, and IL-6. ResultsAfter rhinoplasty, the expression of FPR3 in the capsular tissue increased in proportion to the degree of contracture. By activating the PKA/Rap1/ERK1/2 axis, overexpression of FPR3 can significantly increase the cell viability of fibroblasts and promote their transformation into myofibroblasts. Moreover, FPR3 phosphorylates IκB to decrease NF-κB inhibition, thereby promoting the synthesis and release of the inflammatory cytokines IL-1β, TNF-α, and IL-6. ConclusionFPR3 is a crucial molecule that causes capsular development and contracture following rhinoplasty. In the future, local suppression of FPR3 may be an effective treatment for relieving capsular contracture.

Thymol Ameliorates Aspergillus fumigatus Keratitis by Downregulating the TLR4/ MyD88/ NF-kB/ IL-1β Signal Expression and Reducing Necroptosis and Pyroptosis

Fungal keratitis is a refractory kind of keratopathy. We attempted to investigate the anti-inflammatory role of thymol on Aspergillus fumigatus (A. fumigatus) keratitis. Wound healing and fluorescein staining of the cornea were applied to verify thymol's safety. Mice models of A. fumigatus keratitis underwent subconjunctival injection of thymol. The anti-inflammatory roles of thymol were verified by hematoxylin-eosin (HE) staining, slit lamp observation, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blotting. In contrast with the DMSO group, more transparent corneas and less inflammatory cells infiltration were detected in mice treated with 50 μg/ml thymol. Thymol downregulated the synthesis of TLR4, MyD88, NF-kB, IL-1β, NLRP3, caspase 1, caspase 8, GSDMD, RIPK3 and MLKL. In summary, we proved that thymol played a protective part in A. fumigatus keratitis by cutting down inflammatory cells aggregation, downregulating the TLR4/ MyD88/ NF-kB/ IL-1β signal expression and reducing necroptosis and pyroptosis.