Regulation Of IL-1β Research Articles

IL-1β-mediated NF-κB signaling augments the osteosarcoma cell growth through modulating miR-376c/TGFA axis.

Overexpression of IL-1β, one of the most well-known pro-inflammatory cytokines, is related to a plenty of diseases including cancer. Diversion of microRNAs exposed to pro-inflammatory cytokines have been noted in cancer cells, however, their functions in inflammation stress are still to be further studied. In our previous study, we reported that miR-376c inhibited the growth of osteosarcoma (OS) cells by targeting TGFA. Here, we revealed that miR-376c was downregulated in OS tissues and cells while IL-1β, NF-κB and TGFA were upregulated in OS tissues and cells. IL-1β or NF-κB could promote the OS cells growth through inducing miR-376c expression and decreasing TGFA protein levels. Furthermore, forced expression of miR-376c restored the suppression of IL-1β on the OS cells. A decrease in miR-376c and an increase in TGFA depended on IL-1β-induced NF-κB protein level, which attenuates miR-376c expression upon IL-1β reduction. Taken together, our findings indicated that IL-1β augmented miR-376c-reduction to promote OS cell growth via upregulating NF-κB levels. Knock-down NF-κB suppressed the expression of TGFA. Enhanced TGFA upon IL-1β induction was attenuated by NF-κB inhibition. Hence, the regulation of IL-1β/NF-κB/miR-376c/TGFA signaling in OS might present a promising strategy for the treatment of OS.

Canakinumab for the treatment of familial Mediterranean fever

ABSTRACTIntroduction: Familial Mediterranean fever (FMF) is the most frequent of all hereditary autoinflammatory syndromes. It is characterized by recurrent attacks of fever and serositis. If not treated it may be complicated with AA amyloidosis. It is caused by mutations in the MEFV gene that encodes pyrin which is involved in the regulation of IL-1β. The mainstay of treatment is colchicine, however a subset of patients requires an alternative treatment either due to inadequate response or intolerance. The accumulating data indicates that anti IL-1 drugs are effective in treating colchicine resistant FMF cases and improving their quality of life.Areas covered: This review focuses on canakinumab, a fully human anti IL-1β antibody, treatment in FMF. The data obtained from case reports, case series, two Phase II studies and an ongoing double-blind, randomized, placebo controlled Phase III trial are analyzed. Efficacy and safety profiles of canakinumab are discussed.Expert commentary: Canakinumab became the first approved therapy by the Food and Drug Administration for FMF very recently, which highlights its importance as the alternative treatment in FMF.

Regulated in development and DNA damage responses 1 (REDD1) links stress with IL-1β–mediated familial Mediterranean fever attack through autophagy-driven neutrophil extracellular traps

Familial Mediterranean fever (FMF) is an IL-1β-dependent autoinflammatory disease caused by mutations of Mediterranean fever (MEFV) encoding pyrin and characterized by inflammatory attacks induced by physical or psychological stress. We investigated the underlying mechanism that links stress-induced inflammatory attacks with neutrophil activation and release of IL-1β-bearing neutrophil extracellular traps (NETs) in patients with FMF. RNA sequencing was performed in peripheral neutrophils from 3 patients with FMF isolated both during attacks and remission, 8 patients in remission, and 8 healthy subjects. NET formation and proteins were analyzed by using confocal immunofluorescence microscopy, immunoblotting, myeloperoxidase-DNA complex ELISA, and flow cytometry. Samples from patients with Still's disease and bacterial infections were used also. The stress-related protein regulated in development and DNA damage responses 1 (REDD1) is significantly overexpressed during FMF attacks. Neutrophils from patients with FMF during remission are resistant to autophagy-mediated NET release, which can be overcome through REDD1 induction. Stress-related mediators (eg, epinephrine) decrease this threshold, leading to autophagy-driven NET release, whereas the synchronous inflammatory environment of FMF attack leads to intracellular production of IL-1β and its release through NETs. REDD1 in autolysosomes colocalizes with pyrin and nucleotide-binding domain, leucine-rich repeat/pyrin domain-containing 3. Mutated pyrin prohibits this colocalization, leading to higher IL-1β levels on NETs. This study provides a link between stress and initiation of inflammatory attacks in patients with FMF. REDD1 emerges as a regulator of neutrophil function upstream to pyrin, is involved in NET release and regulation ofIL-1β, and might constitute an important piece in the IL-1β-mediated inflammation puzzle.

The Yersinia pestis Effector YopM Inhibits Pyrin Inflammasome Activation.

Type III secretion systems (T3SS) are central virulence factors for many pathogenic Gram-negative bacteria, and secreted T3SS effectors can block key aspects of host cell signaling. To counter this, innate immune responses can also sense some T3SS components to initiate anti-bacterial mechanisms. The Yersinia pestis T3SS is particularly effective and sophisticated in manipulating the production of pro-inflammatory cytokines IL-1β and IL-18, which are typically processed into their mature forms by active caspase-1 following inflammasome formation. Some effectors, like Y. pestis YopM, may block inflammasome activation. Here we show that YopM prevents Y. pestis induced activation of the Pyrin inflammasome induced by the RhoA-inhibiting effector YopE, which is a GTPase activating protein. YopM blocks YopE-induced Pyrin-mediated caspase-1 dependent IL-1β/IL-18 production and cell death. We also detected YopM in a complex with Pyrin and kinases RSK1 and PKN1, putative negative regulators of Pyrin. In contrast to wild-type mice, Pyrin deficient mice were also highly susceptible to an attenuated Y. pestis strain lacking YopM, emphasizing the importance of inhibition of Pyrin in vivo. A complex interplay between the Y. pestis T3SS and IL-1β/IL-18 production is evident, involving at least four inflammasome pathways. The secreted effector YopJ triggers caspase-8- dependent IL-1β activation, even when YopM is present. Additionally, the presence of the T3SS needle/translocon activates NLRP3 and NLRC4-dependent IL-1β generation, which is blocked by YopK, but not by YopM. Taken together, the data suggest YopM specificity for obstructing the Pyrin pathway, as the effector does not appear to block Y. pestis-induced NLRP3, NLRC4 or caspase-8 dependent caspase-1 processing. Thus, we identify Y. pestis YopM as a microbial inhibitor of the Pyrin inflammasome. The fact that so many of the Y. pestis T3SS components are participating in regulation of IL-1β/IL-18 release suggests that these effects are essential for maximal control of innate immunity during plague.

MiR-100-3p and miR-877-3p regulate overproduction of IL-8 and IL-1β in mesangial cells activated by secretory IgA from IgA nephropathy patients

IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis, characterized by mesangial deposition of pathogenic IgA and the injury to mesangial cells. Our previous studies indicate that secretory IgA (SIgA) plays an important role in the pathogenesis of IgAN, and miR-16 is involved in destructive process in mesangial cells mediated by the SIgA from IgAN patients. Our current study aimed to study the role of miRNAs in the effect of SIgA from IgAN patients on mesangial cells. MicroRNA microarray and cytokines assay were performed to obtain the differential microRNAs expression profile in human renal mesangial cells stimulated by SIgA from IgAN patients (P-SIgA) with the cells treated by SIgA from healthy subjects (N-SgA) as control. The microRNAs with the most significant differences in microarray analysis were validated by quantitative RT-PCR. Among them, miR-100-3p and miR-877-3p were selected to predict target gene related to cytokines detecting in this study. Fifty-six differentially expressed microRNAs were chosen and 17 microRNAs with the most prominent changes were validated. Compared with N-SIgA, P-SIgA increased the production of interleukin (IL)-1β, IL-8, monocyte chemotactic protein-1 and transforming growth factor-β1. In addition, we for the first time demonstrated that over-production of IL-8 induced by the SIgA was regulated by down-expression of miR-100-3p in mesangial cells. Similarly, IL-1β over-production was regulated by down-expression of miR-877-3p. Our findings represent a pathogenic microRNAs expression profiling in human mesangial cells activated by P-SIgA. Furthermore, we provide a new explanation characterizing the molecular mechanism responsible for the regulation of IL-1β and IL-8 production in P-SIgA-triggered mesangial cells.

선모(仙茅) 열수(熱水) 추출물의 Collagen 유발 관절염에 대한 약리 효능 연구

Objectives: In Korean medicine, Curculiginis Rhizoma was treated for arthritis in remedy. But efficacy of Curculiginis Rhizoma on collagen induced arthritis was not revealed.Methods: Anti inflammatory effect of Curculiginis Rhizoma was researched in vitro with RAW264.7 cell and cell toxicity, levels of proinflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-12) and PGE2 were analyzed by ELISA assay. Inflammatory protein were analyzed by western blotting assay (JNK, ERK, COX-2, TNF-α and IL-1β). In vivo, collagen induced arthritis mice model was used to evaluate anti-inflammation effect through arthritis index, immune cell number and cytokine levels (TNF-α, IL-6 and IL-1β) in serum.Results: ECR(Extract of Curculiginis Rhizoma) has not shown cell toxicity in 200 ㎍/㎖ on RAW264.7 cell. ECR suppressed releases of NO, TNF-α, IL-1β, IL-6, IL-12 and PGE2 on RAW264.7 cell treated with lipopolysacharide (1 ㎍/㎖). And ECR inhibited regulation of TNF-α, IL-1β and IL-6 mRNA, reduced protein release of JNK, ERK, iNOS, COX-2, IL-1β and TNF-α. AI of group treated with ECR 200 ㎎/㎏ and 100 ㎎/㎏ were significantly decreased compared to vihicle arthritis mice, the number of immune cell in foot joint was increased on control mice but those of group treated with ECR 200 ㎎/㎏ and 100 ㎎/㎏ were significantly reduced. This results correspond with contens of cytokines (TNF-α, IL-1β and IL-6) in serum.Conclusions: Curculiginis Rhizoma has anti-inflammation effect on RAW264.7 cell in vitro and collagen induced arthritis in vivo. So it is necessary to research more mechanism for cascade imfact.

Anti-Inflammatory Effect of Sedum takesimense Nakai Water Extract in RAW 264.7 Cells

Background: Sedum takesimense Nakai has been used as folk medicine in Korea. The present study aimed to determine the biological activity of S. takesimense by investigating the anti-inflammatory effects of S. takesimense water extract (SKLC) on the lipopolysaccharide-induced inflammatory response in RAW 264.7 cells. Methods and Results: Cytotoxicity of SKLC on RAW 264.7 cells was determinded by performing MTS assay was found to have no cytotoxic effect on RAW 264.7 cells at a concentration range of 62 - 500 ㎍/㎖. Further, pretreatment of SKLC inhibited lipopolysaccharide-induced nitric oxide (NO) production in a dose-dependent manner. To determined the inhibitory mechanisms of SKLC on inflammatory mediators, we assessed the inducible nitric oxide synthase (iNOS) and cyclooxygnease-2 (COX-2) pathways. The activities of these pathways were decreased in a dose-dependent manner by SKLC. The production of tumor necrosis factor- α (TNF-α), interleukin (IL)-1β‚ and IL-6 were also reduced. Conclusions: These results suggest that the down regulation of iNOS, COX-2, TNF-α, IL-1β‚ and IL-6 expression by SKLC are mediated by the down regulation of nuclear factor-κB (NF-κB) activity, a transcription factor necessary for pro-inflammatory mediators. This might be the mechanism underlying the anti-inflammatory effects of SKLC.

617 Molecular Mechanism of microRNA Regulation of IL-1β Induced Increase in Intestinal Tight Junction Permeability

617 Molecular Mechanism of microRNA Regulation of IL-1β Induced Increase in Intestinal Tight Junction Permeability

Altered Th17/Treg balance and dysregulated IL-1β response influence susceptibility/resistance to experimental autoimmune arthritis.

This study was aimed at gaining an insight into immune mechanisms of differential susceptibility to autoimmunity of individuals sharing the same major histocompatibility complex by studying arthritis-susceptible Lewis (LEW) and arthritis-resistant Wistar Kyoto (WKY) rats (both RT.1(l)) using the adjuvant arthritis (AA) model of rheumatoid arthritis (RA). Lymph node cells (LNC) and synovium-infiltrating cells (SIC) of LEW and WKY rat subjected to an arthritogenic challenge were tested. The frequency of T helper 17 (Th17) and T regulatory (Treg) cells was determined by flow cytometry, whereas serum and spleen adherent cell (SAC)-derived supernatant were analyzed for specific cytokines and chemokines. We observed that WKY rats are not deficient in generating a Th17 response to the arthritogenic challenge in LNC (periphery); however, the Th17/Treg ratio is markedly reduced in the joint (target organ) of WKY versus LEW rats because of reduced Th17 levels therein in WKY rats. These results suggest differential and selective decrease in Th17 cell migration into the joints of WKY rats. Interestingly, serum levels of chemokines RANTES and MCP-1 were reduced in WKY rats. Furthermore, WKY rats showed reduced serum IL-1β level in vivo but no defect in IL-1β production by SAC in vitro, suggesting an effective in vivo regulation of IL-1β response. We also unraveled the role of interferon-γ (IFNγ), which we have previously reported to be increased in WKY versus LEW rats, in regulation of IL-1β. Thus, reduced Th17/Treg ratio in the target organ (joints) and decreased systemic IL-1β might contribute to the AA-resistance of WKY rats; whereas the converse factors render LEW more vulnerable to AA.

Spleen Tyrosine Kinase (Syk) Mediates IL-1β Induction by Primary Human Monocytes during Antibody-enhanced Dengue Virus Infection

Approximately 500,000 people are hospitalized with severe dengue illness annually. Antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is believed to contribute to the pathogenic cytokine storm described in severe dengue patients, but the precise signaling pathways contributing to elevated cytokine production are not elucidated. IL-1β is a potent inflammatory cytokine that is frequently elevated during severe dengue, and the unique dual regulation of IL-1β provides an informative model to study ADE-induced cytokines. This work utilizes patient-derived anti-DENV mAbs and primary human monocytes to study ADE-induced IL-1β and other cytokines. ADE of DENV serotype 2 (DENV-2) elevates mature IL-1β secretion by monocytes independent of DENV replication by 4 h postinoculation (hpi). Prior to this, DENV immune complexes activate spleen tyrosine kinase (Syk) within 1 hpi. Syk induces elevated IL1B, TNF, and IL6 mRNA by 2 hpi. Syk mediates elevated IL-1β secretion by activating ERK1/2, and both Syk and ERK1/2 inhibitors ablated ADE-induced IL-1β secretion. Maturation of pro-IL-1β during ADE requires caspase-1 and NLRP3, but caspase-1 is suboptimally increased by ADE and can be significantly enhanced by a typical inflammasome agonist, ATP. Importantly, this inflammatory Syk-ERK signaling axis requires DENV immune complexes, because DENV-2 in the presence of serotype-matched anti-DENV-2 mAb, but not anti-DENV-1 mAb, activates Syk, ERK, and IL-1β secretion. This study provides evidence that DENV-2 immune complexes activate Syk to mediate elevated expression of inflammatory cytokines. Syk and ERK may serve as new therapeutic targets for interfering with ADE-induced cytokine expression during severe dengue.

Knockdown of interleukin-1α does not attenuate LPS-induced production of interleukin-1β in mouse macrophages

IL-1α and IL-1β are synthesized as 31kDa cell-associated precursors following TLR-4 stimulation, but their processing to the mature form and secretion require a second intracellular stimulus. The unique localization of the precursor of IL-1α (pro-IL-1α) to the nucleus suggested a role in transcriptional regulation of inflammatory cytokines. We explored the hypothesis that pro-IL-1α is involved in regulation of IL-1β expression following TLR-4 stimulation. IL-1β mRNA and protein levels were specifically decreased in macrophages from IL-1α-deficient mice following TLR-1/2, TLR-4 or TLR-9 stimulation, supporting the hypothesis. However, activation of the main upstream regulators of IL-1β expression, IRF3, NFkB and p38/JNK, were not reduced in macrophages from IL-1α-deficient mice. In order to assess the specific role of IL-1α in macrophages, we generated mice with myeloid cell deficiency of IL-1α (LyzMCre-loxp). Despite over 90% knockdown of IL-1α, TLR-4 stimulated macrophages from LyzMCre-loxp mice did not produce lower levels of IL-1β compared to IL-1α-loxp-flanked mice. In order to overcome the possibility that effects are caused by the incomplete deficiency of IL-1α, we generated new whole-body IL-1α knockout mice (GeneralCre-IL-1α) and the findings were similar to myeloid cell-deficient IL-1α. Collectively, our findings do not support the previously suggested role of nuclear IL-1α in gene regulation of IL-1β. Rather, they suggest that IL-1α acts mainly as an alarmin that is sequestered in the nucleus following stimulation with TLR-4.

Low magnitude of tensile stress represses the inflammatory response at intervertebral disc in rats

ObjectiveThis study aims to determine if the involvement of tensile stress affects the expressions of inflammatory cytokines interleukin-17(IL-17), interleukin-1β (IL-1β), and inducible nitric oxide synthase (iNOS) at intervertebral discs in vivo.Material and methodSixty-four female Sprague–Dawley rats were randomly divided into four groups: sham, tail-suspended (TS), tail-suspended with needle puncture (TSNP), and single-needle puncture (SNP) groups. A tail-suspension device provides low magnitude of tensile stress (2.45 Newton (N)), and aseptic needle puncture on the tail disc induces inflammatory response. After 4 weeks, the treated discs were harvested for histologic analysis, quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA).ResultPathological examination demonstrated that compared to the sham group, the morphologies of nucleus pulposus (NP) and anulus fibrosus (AF) in TS, SNP, and TSNP groups displayed degenerative changes in varying degrees. Results from RT-qPCR showed that IL-17 and iNOS mRNA expression levels were significantly higher in both TSNP and SNP groups than those in the sham groups. Expression of IL-17 and iNOS are not significantly different between the sham and TS groups (P > 0.05). Compared with the SNP group, the mRNA expression of IL-17 and iNOS in the TSNP groups were markedly decreased (P < 0.05). The regulation of IL-1β and IL-17 detected by ELISA was coincident with the qRT-PCR results.ConclusionThe results from this study suggested that relatively low magnitude tensile stress might play an essential role in the anti-inflammatory process and the relief of low-back pain (LBP).

SIRT1 deficiency in microglia contributes to cognitive decline in aging and neurodegeneration via epigenetic regulation of IL-1β.

Aging is the predominant risk factor for neurodegenerative diseases. One key phenotype as the brain ages is an aberrant innate immune response characterized by proinflammation. However, the molecular mechanisms underlying aging-associated proinflammation are poorly defined. Whether chronic inflammation plays a causal role in cognitive decline in aging and neurodegeneration has not been established. Here we report a mechanistic link between chronic inflammation and aging microglia and a causal role of aging microglia in neurodegenerative cognitive deficits. We showed that SIRT1 is reduced with the aging of microglia and that microglial SIRT1 deficiency has a causative role in aging- or tau-mediated memory deficits via IL-1β upregulation in mice. Interestingly, the selective activation of IL-1β transcription by SIRT1 deficiency is likely mediated through hypomethylating the specific CpG sites on IL-1β proximal promoter. In humans, hypomethylation of IL-1β is strongly associated with chronological age and with elevated IL-1β transcription. Our findings reveal a novel epigenetic mechanism in aging microglia that contributes to cognitive deficits in aging and neurodegenerative diseases.

Curcumin attenuates CFA induced thermal hyperalgesia by modulation of antioxidant enzymes and down regulation of TNF-α, IL-1β and IL-6.

Reactive oxygen species are signaling mediators of nociceptive pathways. Exogenous administrations of antioxidants show anti-hyperalgesic effect. However, very little is known about the role of endogenous antioxidant defense system in pain pathology. Curcumin is a dietary antioxidant which shows ameliorative effect on thermal hypersensitivity, however detailed study is lacking. Present study was aimed to analyze the changes in oxidative stress, modulation of antioxidant enzymes and pro-inflammatory cytokines in complete Freund's adjuvant induced inflammatory hyperalgesia and the effect of curcumin on antioxidant defense system and pro-inflammatory cytokines. Anti-hyperalgesic activity of curcumin was evidenced after 6 h of treatment. Oxidative stress was evidenced in paw skin and spinal cord of hyperalgesic rats by high level of lipid peroxidation. A decrease in activity of antioxidant enzymes like catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase and an increase in level of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 in paw skin was observed as compared to normal rats. However, activity of antioxidant enzymes was enhanced in spinal cord. The changes were brought towards normal level after curcumin treatment. The results suggest that modulation of antioxidant defense system is early event in initiation of inflammatory hyperalgesia which might lead to initiation of other signaling pathways mediated by lipid peroxide, TNF-α, IL-1β and IL-6. Decrease in oxidative stress and down regulation of these cytokines by curcumin is suggested to be involved in its anti-hyperalgesic effect.

104: Negative regulation of IL-1β through the PI3K pathway is mediated by Akt-dependent inactivation of FoxO1 in TIR-stimulated mast cells

Mast cells (MCs) are sentinels located in tissues proximal to the outside environment. They alert the immune system to invasion of various pathogens and create an inflammatory milieu. Upon activation via the family of Toll-IL-1-receptors (TIRs), MCs produce pro-inflammatory cytokines. In order to provide a response, which is appropriate to the type of pathogen and the local tissue MCs need to modulate their cytokine profile by integrating input from the surrounding milieu. We have previously shown that activation of the PI3K pathway augments the secretion of TNF-α and IL-6 but attenuates the synthesis of IL-1β in TIR-ligand-stimulated MCs [1] . Thus, the PI3K pathway represents a basic mechanism to differentially modulate NF-κB-driven, pro-inflammatory cytokines. We are particularly interested in the molecular mechanism that negatively regulates IL-1β downstream of the PI3K. To study this we employ genetic and pharmacological approaches as well as co-stimulation experiments with stimuli that elicit a robust PI3K activation e.g. antigen, steel factor (SF), or IGF-1. Our results indicate that PI3K-dependent regulation of IL-1β expression is mainly facilitated via Akt-dependent inactivation of the transcription factor FoxO1. Inhibition of Akt augments the TIR-ligand-induced IL-1β synthesis and mimics inhibition of PI3K. In line with this finding, IL-1β production is attenuated when FoxO1 is inhibited. Furthermore, we are interested in the exact PI3K isoforms that are engaged by the TIR receptors themselves or by the co-stimulatory receptors and whether these depend on the Akt-FoxO1 axis to modulate the TIR-induced cytokines in MCs. These results may reveal a basic PI3K-dependent mechanism that allows MCs to bias their cytokine profile according to the (patho-) physiological milieu. This will be of relevance for inflammatory responses in the context of cancer and allergic diseases, amongst others.

127: Possible role of IL-10 in the natural resistance of mouse to leptospirosis

Leptospirosis is a widespread zoonosis with more than 1 million cases of human contaminations estimated annually. The disease is polymorphic with asymptomatic forms or clinical manifestations ranging from mild to severe forms possibly leading to death. Using a comparative study between susceptible (hamster) and resistant (OF1 mouse) animals infected with virulent leptospires, we previously showed that the anti-inflammatory interleukin-10 (IL-10), although upregulated in both animals, was rapidly and massively overexpressed in mice. We aimed at better understanding the role of IL-10 in the disease pathophysiology, and its possible involvement in the resistance of mouse to leptospirosis. Using anti-IL-10 antibody (Ab) as a pre-infection treatment, we studied the effect of IL-10 neutralization on the resistance of the OF1 mice infected with virulent leptospires ( Leptospira interrogans serovar Icterohaemorrhagiae). Growth variation was evaluated as a clinical sign after infection. The presence of leptospires was investigated in kidneys at D7; IL-1β and TNF-α gene expression in blood was assessed at D3 using RT-qPCR techniques. While either infection with virulent leptospires or Ab treatment did not affect the growth curve of mice, IL-10 neutralization significantly influenced the mouse growth during the early days (D1 and D2) postinfection suggesting a susceptibility of animals. Leptospires were detected in the kidneys of 5/7 infected mice (71.5%) whereas only 2/8 of Ab-injected animals (25%) were found positive for renal carriage. Quantification of cytokine gene expression did not show regulation of neither IL-1β nor TNF-α in blood of leptospiremic mice at D3. However, both cytokines were significantly up-regulated in infected animals pre-treated with anti-IL-10 ab. Results suggest that IL-10 neutralization might impact on the resistance of mouse to Leptospira infection, possibly related to an up-regulation of IL-1β and TNF-α, illustrating the possible key role of this cytokine in the immune response to leptospirosis.

Effect of Astragalus polysaccharides on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis

AimAstragalus membranaceus is a Chinese medicinal herb and has been shown to improve hapten-induced experimental colitis. One of its major components is polysaccharides. We investigated the effect of Astragalus polysaccharides (APS) on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis. MethodsThe experimental colitis model was induced by TNBS. Forty five rats were divided into five groups (n=9): Normal control group, receiving ethanol vehicle with no TNBS during induction and IP saline injection during treatment; TNBS colitis model group (TNBS+IP saline), receiving only IP saline vehicle treatment; APS low dose group (TNBS+L-APS), receiving APS 100mg/kg; APS high dose group (TNBS+H-APS), receiving APS 200mg/kg; and positive control group (TNBS+Dexm), receiving dexamethasone 0.3mg/kg. The clinical features, macroscopic and microscopic scores were assessed. The expressions of TNF-α, IL-1β and NFATc4 were measured by real-time PCR and ELISA assays. ResultsCompared to normal control rats, TNBS+IP saline had significant weight loss, increased macroscopic and microscopic scores, higher disease activity index (DAI) up-regulation of TNF-α, IL-1β and NFATc4 mRNA expression and up-regulation of TNF-α and IL-1β protein expression. Compared to TNBS+IP saline, treatment with APS or dexamethasone significantly reduced DAI, partially but significantly prevented TNBS colitis-induced weight loss and improved both macroscopic and microscopic scores; high dose APS or dexamethasone significantly down-regulated TNF-α and IL-1β expressions (both mRNA and protein) and up-regulated NFATc4 mRNA and protein expression. The effect of high dose APS and dexamethasone is comparable. ConclusionsAPS significantly improved experimental TNBS-induced colitis in rats through regulation of TNF-α, IL-1β and NFATc4 expression.

Porphyromonas gingivalis-induced reactive oxygen species activate JAK2 and regulate production of inflammatory cytokines through c-Jun.

Pathogen-induced reactive oxygen species (ROS) play a crucial role in host innate immune responses through regulating the quality and quantity of inflammatory mediators. However, the underlying molecular mechanisms of this effect have yet to be clarified. In this study, we examined the mechanism of action of ROS stimulated by Porphyromonas gingivalis in gingival epithelial cells. P. gingivalis induced the rapid production of ROS, which lead to the phosphorylation of JAK2 and increased levels of secreted proinflammatory cytokines interleukin-6 (IL-6) and IL-1β. Neutralization of ROS by N-acetyl-l-cysteine (NAC) abrogated the phosphorylation of JAK2 and suppressed the production of IL-6 and IL-1β. ROS-mediated phosphorylation of JAK2 induced the phosphoactivation of c-Jun amino-terminal protein kinase (JNK) and the downstream transcriptional regulator c-Jun. Inhibition of JAK2, either pharmacologically or by small interfering RNA (siRNA), reduced both the phosphorylation of these molecules and the production of proinflammatory cytokines in response to P. gingivalis. Furthermore, pharmacological inhibition or siRNA-mediated gene silencing of JNK or c-Jun mimicked the effect of JAK2 inhibition to suppress P. gingivalis-induced IL-6 and IL-1β levels. The results show that ROS-mediated activation of JAK2 is required for P. gingivalis-induced inflammatory cytokine production and that the JNK/c-Jun signaling axis is involved in the ROS-dependent regulation of IL-1β and IL-6 production.

Protective effect of hesperetin in rat model of partial sciatic nerve ligation induced painful neuropathic pain: an evidence of anti-inflammatory and anti-oxidative activity

Behavioral, biochemical and gene expression changes were investigated in a rat model of partial sciatic nerve ligation (PSNL) after administration of hesperetin (20, 50mg/kg; p.o.), pregabalin (10mg/kg; p.o.) or vehicle (1ml/kg, p.o.). Thirty-six animals were randomly divided into six groups. Left sciatic nerve was exposed and ligated, animals in the control and test groups were treated orally with respective drugs for fifteen days. Nociceptive threshold was assessed on 0day and thereafter every three days. Three weeks later, sciatic nerve tissue homogenate was prepared and subjected for estimation of oxidative markers namely total protein, nitric oxide, lipid peroxidase, interleukins (IL-1β and IL-6) and TNF-α. Administration of hesperetin resulted in a dose dependent attenuation in PSNL-induced mechanical and thermal hyperalgesia, mechanical allodynia as well as down regulation of IL-1β, IL-6 and TNF-α, and biochemical markers. Consequently, it can be concluded that anti-hyperalgesic effect of hesperetin in rats after PSNL may be attributed to various oxidative markers as well as the pro-inflammatory mediators secreted at the injury site. Hesperetin appears to be a promising candidate for the development as a novel therapeutic for the patients suffering from the neuropathic pain.

Curcumin attenuates carcinogenesis by down regulating proinflammatory cytokine interleukin-1 (IL-1α and IL-1β) via modulation of AP-1 and NF-IL6 in lymphoma bearing mice

Interleukin-1 (IL-1α and IL-1β) is a prototypic, potent, multifunctional proinflammatory cytokine affecting almost all cell types. Expression of IL-1 is up regulated in different tumor phenotypes and is implicated as an important factor in tumor progression via expression of metastatic, angiogenic genes and growth factors. Therefore, down regulation of expression of IL-1 may be able to inhibit cancer progression. Mechanism of transcriptional regulation of mouse IL-1α is not yet reported. AP-1 binding site at -12 to -6 on human IL-1α promotor is highly conserved in rat IL-1α gene and regulates its expression. Based on in silico analysis, regions -12 to -6bp is found to be conserved in human and mouse IL-1α gene promotor and therefore selected to study activation of IL-1α. Further, the regions -12 to -6bp in mouse IL-1α gene promotor corresponding to AP-1 binding element show 3'→5' orientation, necessary for AP-1 binding. The present work is focused on long term effect of curcumin on expression of IL-1α and IL-1β in liver of lymphoma bearing mice. Transcriptional regulation of IL-1α and IL-1β was analyzed by AP-1 and NF-IL-6 respectively. Elevated expression and protein level of IL-1α and IL-1β were found in lymphoma bearing mice compared to normal, which were significantly down regulated by curcumin treatment. Similarly, curcumin treatment down regulated activation of IL-1α and IL-1β via AP-1 and NF-IL-6 respectively. The findings conclude that curcumin attenuates carcinogenesis by down regulating proinflammatory cytokine interleukin-1 (IL-1α and IL-1β) via modulation of AP-1 and NF-IL6 respectively in lymphoma bearing mice.