Higher Concentrations Of IL-1beta Research Articles

181-POS

Objectives Preeclampsia (PE) is a clinical complication of pregnancy associated with high levels of inflammatory cytokines, leukocyte activation and oxidative stress. Autophagy, an intracellular catabolic process, which removes damaged organelles and cytoplasmic proteins seems to be able to maintain cellular homeostasis. Moreover, it also has a potent anti-inflammatory mechanism by destroying inflammasomes, an intracellular multi-protein structure required for processing and releasing bioactive Interleukin-1 beta (IL-1beta). The present study compared the ability of sera from pregnant women with or without preeclampsia to induce autophagy in peripheral blood mononuclear cells (PBMC), and the relationship between this activity and serum concentrations of uric acid, IL-1beta, IL-10 and TNF-alpha. Methods PBMC from 20 healthy non-pregnant women were incubated with sera from 45 pregnant women, being 23 normotensive (NT) and 22 with PE in the presence or absence of rapamycin, an autophagy inducer. After 48h, the cells were assayed for p62, a cytoplasmic protein associated with autophagy inhibition. Sera from both groups of pregnant women were tested for IL-1beta, IL-10 and TNF-alpha by enzyme-linked immunosorbent assay. Results Autophagy was induced to a greater extent by sera from women with PE than by NT pregnant women. The relationship between inflammatory cytokines in sera of preeclamptic pregnant women showed association between autophagy induction (decrease in cytoplasmic p62) and higher concentrations of IL-1beta ( r = −0.4949; p = 0.0192), and TNF-alpha ( r = − 0.5302; p = 0.0111). This relationship was absent in sera from NT women. There was no association between IL-10 or uric acid levels and autophagy both in preeclamptic and NT group. Conclusions Association between autophagy induction and higher levels of inflammatory cytokines in sera from patients with preeclampsia suggests that the enhanced pro-inflammatory state characteristic of preeclampsia may result in the up-regulation of autophagy induction in these women. Financial support: Fapesp 2014/00693-9. Disclosures M.L. Matias: None. M.T. Peracoli: None. T.T. Kanninen: None. G. Sisti: None. M. Romao: None. I.C. Weel: None. J.C. Peracoli: None. A.M. Bongiovanni: None. S.S. Witkin: None.

Imbalance in the peritoneal levels of interleukin 1 and its decoy inhibitory receptor type II in endometriosis women with infertility and pelvic pain

To evaluate the levels of interleukin-1beta (IL1beta) and its inhibitory soluble interleukin-1 receptor type II (IL1R2) in the peritoneal fluid (PF) of normal women and patients with endometriosis suffering from pelvic pain and infertility. Retrospective study using ELISA to measure peritoneal fluid IL1beta and soluble IL1R2. Gynecology clinic and human reproduction research laboratory. Sixty-eight normal women and 154 women with endometriosis. Peritoneal fluid samples were obtained at laparoscopy. IL1beta and soluble IL1R2 concentrations in the PF samples. This study showed a marked decrease in peritoneal soluble IL1R2 levels in women with endometriosis compared to normal women and a concomitant increase in the levels of IL1beta. Both fertile and infertile women with endometriosis had lower soluble IL1R2 and higher IL1beta concentrations than fertile women having a normal gynecological status, but the difference was more significant in infertile endometriosis patients. Compared with normal controls, the decrease in soluble IL1R2 levels was less significant in women with endometriosis than without pelvic pain, whereas the increase in IL1beta concentrations was statistically significant only in women with endometriosis reporting pelvic pain. This study revealed an imbalance between IL1beta and its decoy inhibitory receptor type 2 in women with endometriosis, which was particularly obvious in those who were infertile, and suggests that a defect in the local control of IL1 may be involved in the pathophysiology of endometriosis and related infertility.

Stab Incision for Inducing Intervertebral Disc Degeneration in the Rat

The degenerative response of rat tail and lumbar intervertebral discs to a stab incision was evaluated. To examine and compare the postinjury degenerative response of lumbar and tail discs. Although successful in larger animals, a stab incision for inducing disc degeneration in rats has not been evaluated. Rodents are desirable models for disc repair studies due to their low cost, ease of care, and fast healing times. Lumbar and tail discs were exposed surgically and stabbed with a number 11 blade. Disc architecture, levels of IL-1beta, IL-6, and TNF-alpha, and biomechanical properties were analyzed. A functional disability secondary to multilevel lumbar disc injury was quantified and compared with that of rats undergoing sham surgery. Histologic evaluation of stabbed tail discs demonstrated a nucleus pulposus size decrease, anular collagen layer disorganization, and cellular metaplasia of anular fibroblasts to chondrocyte-appearing cells. Besides the continued presence of the stab injury tract, few changes were observed in the lumbar disc histology. Cytokine measurements indicated a transient peak in IL-1beta in tail discs 4 days following injury. No significant changes in IL-1beta, IL-6, or TNF-alpha were measured. No significant differences in biomechanical properties were observed between stab injury and sham surgery discs. Yet, despite insignificant differences in histologic, cytochemical, or biomechanical properties in the lumbar discs, the rats with lumbar stab injury had a significant decrease in walking ability 28 days after surgery. Tail disc stab injury was successful in creating morphologic signs of degeneration and transient high concentrations of IL-1beta. However, the degenerative response in the lumbar discs was much slower, suggesting that site-specific factors, such as increased stability due to posterior elements and torso musculature, helped facilitate healing. Yet, functional assessment indicated that the rats were partially disabled by multiple lumbar injuries.

Local and Systemic Cytokine Levels in Relation to Changes in Vaginal Flora

Bacterial vaginosis (BV) is associated with increased risk of obstetrical and gynecologic complications and acquisition of sexually transmitted diseases. Despite this, very little is known about the pathogenesis of this disease. Interleukin (IL)-1 beta , tumor necrosis factor- alpha , IL-6, and IL-8 concentrations in vaginal wash and serum samples from women with normal flora, intermediate flora, and BV (determined by Nugent criteria) were measured by enzyme-linked immunosorbent assay. Cytokine levels were not different between women with intermediate flora and women with BV. Women with either intermediate flora or BV had significantly higher concentrations of IL-1 beta in vaginal wash samples than did women with normal flora. The presence of IL-1 beta in vaginal wash samples was associated with >30 Gardnerella or Prevotella morphotypes per high-power field, as detected by Gram staining of vaginal swab specimens. Variation in the numbers of Lactobacillus and Mobiluncus species did not influence local cytokine levels. Serum cytokine levels were not influenced by any changes in vaginal flora. Women with intermediate flora generate significant cytokine responses. It is possible that the risks associated with BV may also affect women with intermediate flora and that appropriate treatment may reduce such risk.

Freshly isolated osteoarthritic chondrocytes are catabolically more active than normal chondrocytes, but less responsive to catabolic stimulation with interleukin‐1β

Interleukin-1beta (IL-1beta) is one potentially important cytokine during cartilage destruction. The aim of this study was to investigate whether there are different effects of low and high concentrations of IL-1beta on the expression level of anabolic genes (type II collagen, aggrecan), catabolic genes (matrix metalloproteinase 1 [MMP-1], MMP-2, MMP-3, MMP-13, and ADAMTS-4), and cytokines (IL-1beta, IL-6, and leukemia inhibitory factor [LIF]) by articular chondrocytes (normal and osteoarthritic). Determination of whether there was a difference in reactivity between normal and osteoarthritic chondrocytes was also a goal of this study. Gene expression levels were detected by real-time polymerase chain reaction from isolated (nonpassaged) chondrocytes (normal [n = 6]; osteoarthritic [n = 7]) after stimulation with 0.01 ng, 0.1 ng, 1 ng, and 10 ng/ml IL-1beta. In normal adult articular chondrocytes the expression of both aggrecan and type II collagen genes was significantly down-regulated, whereas matrix-degrading proteases (except MMP-2), as well as the investigated cytokines, were induced by IL-1beta in a dose-dependent manner. The strongest regulation was found for IL-6 and LIF. Osteoarthritic chondrocytes showed strongly increased levels of catabolic enzymes and mediators, but were less responsive to further stimulation with IL-1beta. Our study confirms that IL-1beta activity is critically dependent on both the applied concentration and the reactivity of the cells stimulated. The responsiveness appears to be significantly reduced in late-stage osteoarthritic chondrocytes. However, these cells show high basic expression levels of catabolic enzymes and mediators. Thus, it remains open whether our data indicate that osteoarthritic chondrocytes are per se not responsive to IL-1beta or are already so strongly stimulated (e.g., by IL-1) during the disease process that they are refractory to further stimulation.

Plasma levels of interleukin-1beta, interleukin-2 and interleukin-4 in recently diagnosed type 1 diabetic children and their association with beta-pancreatic autoantibodies

Type 1 diabetes is an organ specific autoimmune disease whose incidence is increasing worldwide. A functional imbalance in cytokine production resulting in dominance of T helper (Th1) over Th2-type response has been suggested to play a critical role in the pathogenesis of type 1 diabetes. To measure serum concentrations of interleukin (IL)-1beta, IL-2 and IL-4 in children with recently diagnosed type 1 diabetes and to evaluate the autoimmune response measuring glutamic acid decarboxylase (GAD65) and tyrosine phosphatase like (IA-2) autoantibodies. 120 diabetic children and 118 age and gender matched control children, were recruited for this study. Circulating levels of IL-1beta IL-2 and IL-4 were measured by ELISA. GAD65 and IA-2 were measured by RIA. Circulating levels of IL-1beta were elevated in type 1 diabetic children as compared to the control group (9.3 +/- 7.3 and 4.9 +/- 3.8 pg/ml respectively, p=0.01). Serum concentration of IL-2 was also higher in diabetic patients (19.8 +/- 13.1 and 113 +/- 9.1 pg/ml respectively, p=0.01). No differences in serum IL-4 were observed between diabetics and control. Diabetic children with one or two positive autoantibodies (IA-2 and/or GAD65) had significantly higher levels of IL-1beta and IL-2 and lower levels of IL-4 than diabetic children without positive autoantibodies. High concentrations of IL-1beta were associated with an early onset of the disease. High levels of IL-1beta and IL-2 were found in diabetic children with recent diagnosis of the disease. Diabetics with positive antibodies against GAD65 and IA-2 had higher levels of IL-1beta and IL-2 and lower levels of IL-4 than their counterparts without positive antibodies.

Cytokine-induced functional suppression of microencapsulated rat pancreatic islets in vitro.

It is likely that inflammatory cytokines are released near microencapsulated islets in vivo. Rates of insulin release or glucose oxidation were measured after culture of microencapsulated rat islets with interleukin (IL)-1beta and tumor necrosis factor-(TNF-alpha). Their ability to recover from IL-1beta-induced suppression was also investigated. Microencapsulated islets were suppressed after exposure to IL-1beta, which was potentiated by TNF-alpha. After exposure to lower IL-1beta concentrations, microencapsulated islets had similar oxidation rates as corresponding controls. At higher concentrations, microencapsulated islets were more suppressed than nonencapsulated islets. Microencapsulated and control islets were able to recover from suppression after exposure to 2.5 U/ml of IL-1beta. Microencapsulation using the present alginate/poly-L-lysine/alginate capsules does not protect islets against the detrimental effects of IL-1beta and TNF-alpha. Indeed, microencapsulated islets seem to be more susceptible to suppression at higher concentrations of IL-1beta. However, after exposure to a lower concentration of IL-1beta, microencapsulated islets can recover.

Bimodal Regulation of Ceramidase by Interleukin-1β: IMPLICATIONS FOR THE REGULATION OF CYTOCHROME P450 2C11 (CYP2C11)

Interleukin 1beta (IL-1beta) induces the hydrolysis of sphingomyelin (SM) to ceramide (Cer) in primary cultures of rat hepatocytes, and Cer has been proposed to play a role in the down-regulation of cytochrome P450 2C11 (CYP2C11) and induction of alpha1-acid glycoprotein (AGP) by this cytokine (Chen, J., Nikolova-Karakashian, M., Merrill, A. H. & Morgan, E. T. (1995) J. Biol. Chem. 270, 25233-25238). Nonetheless, some of the features of the down-regulation of CYP2C11 do not fit a simple model of Cer as a second messenger as follows: N-acetylsphinganine (C2-DHCer) is as potent as N-acetylsphingosine (C2-Cer) in suppression of CYP2C11; the IL-1beta concentration dependence for SM turnover is different from that for the increase in Cer; and the increase in Cer mass is not equivalent to the amount of SM hydrolyzed nor the time course of SM hydrolysis. In this article, we report that these discrepancies are due to activation of ceramidase by the low concentrations of IL-1beta ( approximately 2.5 ng/ml) that maximally down-regulate CYP2C11 expression, whereas higher IL-1beta concentrations (that induce AGP) do not activate ceramidase and allow Cer accumulation. This bimodal concentration dependence is demonstrated both by in vitro ceramidase assays and in intact hepatocytes using a fluorescence Cer analog, 6-((N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)-Cer (NBD-Cer), and following release of the NBD-fatty acid. IL-1beta increases both acid and neutral ceramidase activities, which appear to be regulated by tyrosine phosphorylation because pretreatment of hepatocytes with sodium vanadate increases (and 25 microM genistein reduces) the basal and IL-1beta-stimulated ceramidase activities. Since these findings suggested that sphingosine (and, possibly, subsequent metabolites) is the primary mediator of the down-regulation of CYP2C11 by IL-1beta, the effects of exogenous sphingosine and C2-Cer on expression of this gene were compared. Sphingosine was more potent than C2-Cer in down-regulation of CYP2C11 when added alone or with fumonisin B1 to block acylation of the exogenous sphingosine. Furthermore, the suppression of CYP2C11 by C2-Cer (and C2-DHCer) is probably mediated by free sphingoid bases, rather than the short chain Cer directly, because both are hydrolyzed by hepatocytes and increase cellular levels of sphingosine and sphinganine. From these observations we conclude that sphingosine, possibly via sphingosine 1-phosphate, is a mediator of the regulation of CYP2C11 by IL-1beta in rat hepatocytes and that ceramidase activation provides a "switch" that determines which sphingolipids are elevated by this cytokine to produce multiple intracellular responses.

IL-5 synthesis is upregulated in human nasal polyp tissue

In most nasal polyps, tissue eosinophilia is a striking finding, the pathologic mechanism of which is not understood. This study was performed to investigate a possibly distinct cytokine and chemokine pattern that could explain the characteristic tissue eosinophilia in nasal polyps. Polyps from 23 patients and turbinate tissue from 18 control subjects were investigated. The cytokine protein content (IL-1 beta, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, tumor necrosis factor-alpha, granulocyte-macrophage colony-stimulating factor, IL-1RA, RANTES, GRO-alpha) of tissue homogenates was measured by ELISA. Immunohistochemistry was performed in selected samples to detect IL-5+, major basic protein-positive, and EG2+ cells. IL-5 was detectable in only one sample of tissue from 18 control subjects but was found in 18 of 23 nasal polyps. Immunohistochemistry revealed an abundant number of IL-5+ cells, of which 69.5% could be identified as eosinophils by morphology. IL-6, IL-8, IL-10, tumor necrosis factor-alpha, GRO-alpha, and RANTES were detected in all specimens, without significant differences between groups (p > or = 0.05), whereas significnatly higher concentrations of IL-1 beta and IL-1RA were found in turbinate mucosa (p < or = 0.05). IL-3 was not detectable: granulocyte-macrophage colony-stimulating factor could only occasionally be found. This study indicates that IL-5 plays a key role in the pathophysiology of eosinophilic nasal polyps and may be produced by eosinophils.

Differential effects of prednisolone and indomethacin on zymosan-induced inflammation in a modified murine tissue-chamber model.

A tissue-chamber model of inflammation in mice has been modified and used to investigate the kinetics of zymosan-induced inflammatory mediators such as tumour necrosis factor alpha (TNF alpha), interleukin-1 beta (IL-1 beta) and prostaglandin E2 (PGE2). In addition, the influx of polymorphonuclear leukocytes (PMN) into the chamber fluid and the granuloma surrounding the chamber was measured by myeloperoxidase (MPO) activity using a new microtitre plate assay. TNF alpha and IL-1 beta reached a peak concentrations at 3 and 6 h respectively after zymosan injection. Intermediate high concentrations of IL-1 beta were observed until the end of the experiment at 72 h, but TNF alpha concentrations decreased from 24 h to biologically insignificant values. In contrast, exudate PGE2 and MPO activity increased up to 24 h after zymosan injection and remained high until 72 h. At 6 h after zymosan challenge, oral pre-treatment with prednisolone (3 to 30 mg/kg) dose-dependently reduced TNF alpha, IL-1 beta and PGE2 concentrations while indomethacin (0.3 to 3 mg/kg) significantly attenuated PGE2, slightly enhanced TNF alpha and had no effect on IL-1 beta concentrations in the exudate. Both drugs had similar potencies against exudate and tissue MPO activities. Prednisolone inhibited IL-1 beta at 72 h post-zymosan. Indomethacin was more potent than prednisolone against PGE2 (ID50 of< 0.3 versus 0.6 mg/kg). The data obtained confirm the usefulness and reliability of this model in evaluating the effects of anti-inflammatory agents on inflammatory mediators induced by zymosan.

Influence of tumour necrosis factor-alpha, tumour necrosis factor-beta and interferon-gamma, separately and added together with interleukin-1 beta, on the function of cultured human thyroid cells.

Interleukin (IL)-1, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma have been demonstrated in thyroid tissue. We have previously shown that high concentrations of IL-1 inhibit and low concentrations stimulate human thyroid cell function in vitro. In the present study, TNF-alpha, TNF-beta and IFN-gamma all inhibited thyroglobulin (Tg) and cAMP production from cultured human thyroid cells. When TNF-alpha was added simultaneously with IL-1 beta, the highest concentration of TNF-alpha (10(6) U/l) enhanced the inhibition of Tg and cAMP induced by IL-1 beta (1-10(5) U/l). TNF-beta had no influence on IL-1 beta-induced inhibition. IFN-gamma (10(4) U/l) added together with IL-1 beta in lower concentrations (1-10(2) U/l) stimulated cAMP production, while at high concentrations of IL-1 beta (10(5) U/l), IFN-gamma enhanced the inhibitory influence of IL-1 beta on Tg production. The hormones of the immune system, IL-1, TNF and IFN-gamma, may thus contribute to the decreased thyroid function characteristic of some thyroid inflammatory diseases.

Compartmentalized cytokine production within the human lung in unilateral pneumonia.

The in situ inflammatory response developing in the human lung during a localized bacterial infection was studied in 15 patients with unilateral community-acquired pneumonia (CAP). The local response in the involved lung was compared with that in the contralateral, noninvolved lung as well as with the systemic blood response. Eight healthy volunteers served as control subjects. Concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interleukin-6 (IL-6) were measured by ELISA in bronchoalveolar lavage (BAL) fluids (n = 15), serum (n = 15), and alveolar macrophage and monocyte culture supernatants (n = 8). The concentrations of TNF-alpha, IL-beta and IL-6 in BAL fluid were significantly higher in the involved lung than in the paired noninvolved lung (p < or = 0.01) or in healthy subjects (p < or = 0.02, p < or = 0.01, and p < or = 0.001, respectively). Serum IL-6 concentrations were higher in patients than in control subjects, whereas IL-1 beta and TNF-alpha concentrations did not differ in the two groups. Alveolar macrophages from the involved lung spontaneously released higher concentrations of IL-1 beta, IL-6, and TNF-alpha (p < or = 0.05) than did macrophages from the noninvolved lung, which served as controls. However, macrophages were hyporesponsive in terms of cytokine production to further stimulation by lipopolysaccharide (LPS) in the noninvolved and involved lung compared with controls, whereas peripheral blood monocytes were not.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulse exposure to protein synthesis inhibitors enhances vascular responses to des‐Arg9‐bradykinin: possible role of interleukin‐1

1. The modulation of the spontaneous increase in contractile responses to des-Arg9-bradykinin (des-Arg9-BK) of rabbit aortic strips incubated in vitro was studied. Rapid hypotensive responses to exogenous kinins were also measured in rabbits anaesthetized 5 h following pretreatment. 2. Continuous exposure to the protein synthesis inhibitors cycloheximide (71 microM) or anisomycin (3.8 microM) profoundly inhibited the sensitization to des-Arg9-BK in incubated aortic strips. However, temporary (3 h) inhibition of protein synthesis in vitro followed by further incubation (3 h) of tissues without inhibitor, paradoxically enhanced both the maximal contractile responses to des-Arg9-BK (1.7 microM) and the apparent affinity of the kinin without affecting contractions to noradrenaline (NA, 100 nM) at 6.5 h. 3. The stimulatory activity of the short treatment (pulse) with cycloheximide was abolished in the presence of dexamethasone sodium phosphate (100 microM throughout the incubation). The function of receptors for kinins did not appear to be altered directly by the steroid treatment. 4. Interleukin-1 beta (IL-1 beta), applied at low concentrations (100-250 pg ml-1) on aortic strips between 3 h and 6.5 h of incubation time, mimicked the selective stimulatory effect of the cycloheximide pulse on responses to des-Arg9-BK. Higher concentrations of IL-1 beta (0.5-5 ng ml-1) did not further amplify the responses to des-Arg9-BK but decreased the contractile responses to NA. 5. The modulation by IL-1 beta of vascular sensitivity to des-Arg9-BK and to NA was prevented by blockade of protein synthesis. 6. The induction in vivo by IL-1 beta (5 micrograms kg-1) or by cycloheximide (10 mg kg-1) of cardiovascular responsiveness to des-Arg9-BK was demonstrated with a blood pressure assay of exogenous kinins or with tissues isolated ex vivo 5 h after pretreatment of animals. Evidence of active disposition of cycloheximide in vivo was also obtained. 7. We propose the production of endogenous IL-1 as a possible mechanism for the enhancement of responsiveness to des-Arg9-BK observed in tissues pulsed with a protein synthesis inhibitor and for the inducing effect of cycloheximide or E. coli lipopolysaccharide in vivo. These results suggest that effects mediated by the BK1 receptor for kinins are potentially present in pathological conditions associated with IL-1 production.

The effect of interleukin 1 beta on proteoglycans synthesized by human gingival fibroblasts in vitro.

The effect of recombinant interleukin-1 beta (IL-1 beta) on proteoglycan synthesis by human gingival fibroblasts was investigated. IL-1 beta stimulated the gingival fibroblasts to proliferate. When compared to human foreskin fibroblasts, the gingival fibroblasts demonstrated a greater proliferative response at higher concentrations of IL-1 beta. The midpoint of the proliferation response for both cell types was in the 10(-11) M IL-1 beta range. The rate of [35S]-sulfate incorporation into proteoglycans by human gingival fibroblasts was enhanced by 40% at 10(-9) M IL-1 beta. This stimulatory effect appeared to be independent of cell proliferation and prostaglandin synthesis since blocking of these functions with hydroxyurea and indomethacin respectively, resulted in similar dose responses to IL-1 beta. Pulse chase experiments indicated the kinetics of degradation in the presence or absence of IL-1 beta were essentially identical. Therefore, the turnover rate of proteoglycans was not altered by IL-1 beta, no significant differences between molecular species, size or glycosaminoglycan composition of the proteoglycans synthesized in the presence or absence of IL-1 beta was noted. Thus, IL-1 beta can modulate extracellular matrix synthesis by human gingival fibroblasts and may therefore be partially responsible for the early events of healing following inflammatory episodes.