Biologic effects of an interleukin-1 receptor antagonist protein on interleukin-1-stimulated cartilage erosion and chondrocyte responsiveness

Recombinant human interleukin-1 alpha (IL-1 alpha) and recombinant human IL-1 beta stimulate matrix proteoglycan degradation and inhibit glycosaminoglycan synthesis in bovine nasal cartilage explants. A 17-kd human recombinant IL-1 receptor antagonist protein (IRAP) caused a concentration-dependent (0.2-200 ng/ml) suppression of the effects of IL-1 alpha and IL-1 beta in cartilage organ cultures. IRAP inhibited the binding of radiolabeled IL-1 alpha to rabbit articular chondrocytes. Matrix metalloproteinase (collagenase, gelatinase, and stromelysin) and prostanoid production by IL-1-activated rabbit articular chondrocytes was also suppressed by IRAP. These results could have potential significance in the development of a new antiarthritis therapy based on an IRAP.     

Inhibition of interleukin-1 by an interleukin-1 receptor antagonist prevents graft-versus-host disease.

Graft-versus-host disease (GVHD) is the major complication of allogeneic bone marrow transplantation (BMT). Dysregulation of inflammatory monokines such as tumor necrosis factor alpha (TNF alpha) has been noted in both clinical and experimental GVHD. We present evidence that interleukin-1 (IL-1), another inflammatory monokine, is an important mediator of GVHD. Expression of the gene for IL-1 alpha as well as the gene for TNF alpha is increased in the skin of mice with GVHD. Inhibition of IL-1 function by the in vivo administration of IL-1 receptor antagonist (IL-1ra) reduces the immunosuppression and mortality of GVHD without impairing the engraftment of hematopoietic stem cells. GVHD thus appears to be a systemic inflammatory process in which monokines, especially IL-1, appear to be important mediators. Inhibition of IL-1 by IL-1ra represents a novel approach to the understanding and control of GVHD.     

Acute and short-term effects of the nonpeptide endothelin-1 receptor antagonist bosentan in humans

Summary In recent years, evidence from various animal experiments has accumulated that emphasizes the role of endothelin-1 in the pathophysiology of several cardiovascular diseases, including congestive heart failure. The recent advent of potent antagonists of this system now allows the assessment of the involvement of endothelin-1 in the maintenance of vascular tone in animals and humans. We report hemodynamic data from two trails in patients with chronic severe congestive heart failure (i.e., reduced left ventricular ejection fraction of <30%, elevated resting pulmonary capillary wedged pressure >15 mmHg, and/or reduced cardiac index of 2.5 L/min/m² or less) who were treated with the mixed endothelin-type A and type B-receptor antagonist bosentan. In the first study, the acute effect of bosentan (300 mg, intravenous) on hemodynamics and neurohormones was investigated. Bosentan was well tolerated and significantly improved impaired hemodynamics due to systemic and venous vasodilation. In the second trial, bosentan was given orally (0.5 g bid) for 14 days, in addition to conventional triple treatment for congestive heart failure, including digitalis, angiotensin-converting enzyme inhibitors, and diuretics. Cardiac hemodynamics were monitored during the first 24 hours of treatment, and measurements were repeated during the last day of bosentan therapy. Bosentan was well tolerated in these patients as well, and hemodynamic measures were compatible with an additional effect of bosentan after 2 weeks. However, there was a slight increase in heart rate as well. Our result underline the importance of endogenously generated endothelin-1 in congestive heart failure and suggest a potential benefit of endothelin antagonism in such patients. However, long-term studies are needed to establish whether chronic endothelin antagonism has beneficial clinical effects and is capable of improving survival and/or symptoms in severe heart failure patients who remain symptomatic despite standard triple therapy.     

Recombinant monocyte-derived interleukin-1 receptor antagonist reverses inhibitory effects of interleukin-1 on Leydig cell steroidogenesis.

Previously we have reported that interleukin-1 (IL-1) is a potent inhibitor of Leydig cell function. Most recently, IL-1 receptor antagonist (IL-1ra) has been purified, sequenced and cloned. In the present study, we evaluated the recombinant monocyte-derived IL-1ra on the inhibitory effects of IL-1. The addition of recombinant human IL-1ra up to 1000 ng/ml has no discernible effects on human chorionic gonadotropin (hCG)-stimulated testosterone formation in primary cultures of rat Leydig cells. Similar to that reported previously, IL-1 beta caused a dose-dependent inhibition of hCG-induced testosterone. The inhibitory effect of IL-1 beta could be reversed by the concomitant addition of IL-1ra. The amounts of IL-1ra required to reverse the effect of IL-1 were 25-fold higher. Our results suggest that IL-1 is important in modulating Leydig cell function and its effect most likely is mediated by specific IL-1 receptors.     

Importance of interleukin-1 and interleukin-1 receptor antagonist in short-term glucose sensor function in vivo

Background

The importance of the interleukin (IL)-1 cytokine family in inflammation and immunity is well established as a result of extensive in vitro and in vivo studies. In fact, much of our understanding of the in vivo importance of interleukin-1beta (IL-1B) is the result of research utilizing transgenic mice, such as overexpression or deficiencies of the naturally occurring inhibitor of IL-1 known as interleukin-1 receptor antagonist (IL-1RA). For the present studies, we utilized these transgenic mice to determine the role of IL-1B in glucose sensor function in vivo.

Methods

To investigate the role of IL-1B in glucose sensor function in vivo, we compared glucose sensor function in trans-genic mice that (1) overexpressed IL-1RA [B6.Cg-Tg(II1rn)1Dih/J] and (2) are deficient in IL-1RA (B6.129S-Il1rn^tm1Dih/J), with mice that have normal levels of IL-1RA (C57BL/6).

Results

Our studies demonstrated that, during the first 7 days post-sensor implantation (PSI), mice deficient in IL-1RA had extensive inflammation and decreased sensor function when compared to normal or IL-1RA-overexpressing mice.

Conclusion

These data directly support our hypothesis that the IL-1 family of cytokines and antagonists play a critical role in controlling tissue reactions and thereby sensor function in vivo during the first 7 days PSI.     

Erythrocyte glutathione concentration and production during hyperinsulinemia, hyperglycemia, and endotoxemia in healthy humans

In diabetes mellitus and sepsis, low erythrocyte glutathione (GSH) concentrations are found. Whether this is caused by lowered GSH production has not been clarified. To obtain insight in the relationship between erythrocyte GSH concentrations and GSH production, GSH kinetics were measured in healthy male volunteers during 4 different clamps (low-dose or medium-dose insulin [100 or 400 pmol/L] and euglycemia or hyperglycemia [5 or 12 mmol/L]) in a control setting (n = 6; all 4 clamps in the same subject) or after systemic administration of lipopolysaccharide (to mimic sepsis) (4 groups of n = 6; each clamp in a different subject). Hyperinsulinemia decreased erythrocyte GSH concentration (P = .042), but did not affect fractional synthetic rate (FSR) of GSH. Hyperglycemia did not affect erythrocyte GSH concentration, but decreased FSR of GSH (P = .025). Lipopolysaccharide decreased erythrocyte GSH concentration (P < .001), but increased FSR of erythrocyte GSH (P = .035). Depending on the metabolic circumstances, we found either stable GSH concentrations with lower production rates or decreased levels with either no change or an increase in production rate. Based upon these data, it seems inappropriate to infer conclusions about changes in synthesis rate of GSH from changes in its concentration.     

Treatment of rheumatoid arthritis by interleukin-1 receptor antagonist

PURPOSE: Interleukin -1 receptor antagonist ( IL-1Ra ) is a new option among biotherapies against rheumatoid arthritis ( RA ). THE AIM: of this review is to recall the rationale of use of IL-1Ra and to analyse the results available in the current literature. CURRENT KNOWLEDGE AND KEY POINTS: Pathophysiological data of RA give a specific position for IL-1 as a potential target for immunotherapy in this disease, confirmed in animal models. Phase II and III studies with IL-1Ra (Anakinra) demonstrated clinical efficacy versus placebo (42% responders in ACR 20 in Anakinra + methotrexate, and 23% in the placebo + methotrexate group at 24 weeks) and a structural effect (slowing of radiological progression at six months). Anakinra has obtained an European license and is indicated in RA not controlled by methotrexate, in daily subcutaneous administration (100 mg/day), in combination with methotrexate. Tolerance is fair; the most frequent side effect is represented by injection site reactions. FUTURE PROSPECTS AND PROJECTS: This ambulatory biotherapy offers new perspectives in combination with other slow acting drugs as well as biologic agents such as anti-TNF, currently under evaluation.     

Polymorphisms of interleukin-1B and interleukin-1 receptor antagonist genes in patients with chronic hepatitis B

AIM:To investigate the relationships between polymorphismsof interleukin-1B(IL-1B)promoter region -511C/T andinterleukin-1 receptor antagonist gene(IL-1RN)andsusceptibility to chronic hepatitis B in Chinese population.METHODS:Genomic DNA was extracted from the peripheralblood of 190 patients with chronic hepatitis B and 249 normalcontrols and then subjected to polymerase chain reaction(PCR)amplification.The PCR products were digested byrestriction endonuclease AvaI.The products of digestion weresubjected to 20 g/L gel electrophoresis and ethidium bromidestaining.RESULTS:The frequencies of IL-1B(-511)genotypes CC,CT and Tr in patients with chronic hepatitis B were 23.7%,49.5% and 26.8%,while 26.1%,47.4% and 26.5%respectively in controls.The results showed that there wasno significant difference in the frequencies of alleles orgenotypes in IL-1B between patients with chronic hepatitisB and controls.The distributions of IL-1B(-511)genotypeCC were significantly different between the two subgroups(HBV-DNA≤1×10~3 copies/mL as subgroup I,HBV-DNA>1×10~3 copies/mL as subgroup Ⅱ)of chronic hepatitis B(P=0.029).Only four of the five kinds of polymorphism(1/1,1/2,2/2 and 1/4)were found in this study.The frequenciesof IL-1RN genotypes 1/1,1/2,2/2 and 1/4 were 88.9%,9.0%,0.5% and 1.6% in patients with chronic hepatitis B respect,while were 81.1%,16.9%,0.4% and 1.6% respectively incontrols.The frequencies of genotypel/2 and IL-1RN allele2 in patients with chronic hepatitis B were lower than thosein controls(P=0.016 and P=0.029,respectively).CONCLUSION:There is an association between polymorphismsof the promoter region -511C/T of IL-1B and IL-1RN intron 2and chronic hepatitis B virus infection.Subjects with IL-1RN2 may be resistant to HBV infection,and IL-1B(-511)genotype CC is closely related with HBV-DNA replication,which gives some new clues to the study of pathogenesis ofchronic hepatitis B.     

Polymorphisms of interleukin-1B and interleukin-1 receptor antagonist genes in patients with chronic hepatitis B

AIM：To investigate the relationships between polymorphisms of interleukin-lB (IL-1B) promoter region -511CLT and interleukin-1 receptor antagonist gene (IL-1RN) and susceptibility to chronic hepatitis B in Chinese population. METHODS: Genomic DNA was extracted from the peripheral blood of 190 patients with chronic hepatitis B and 249 normal controls and then subjected to polymerase chain reaction (PCR) amplification. The PCR products were digested by restriction endonuclease AvaI. The products of digestion were subjected to 20 g/L gel electrophoresis and ethidium bromide staining. RESULTS: The frequencies of IL-1B (-511) genotypes CC, CT and TT in patients with chronic hepatitis B were 23.7%, 49.5% and 26.8%, while 26.1%, 47.4% and 26.5% respectively in controls. The results showed that there was no significant difference in the frequencies of alleles or genotypes in IL-1B between patients with chronic hepatitis B and controls. The distributions of IL-1B (-511) genotype CC were significantly different between the two subgroups (HBV-DNA ≤1&#215;10^3 copies/mL as subgroup I, HBV-DNA&gt; 1&#215;10^3 copies/mL as subgroup Ⅱ) of chronic hepatitis B (P=0.029). Only four of the five kinds of polymorphism (1/1, 1/2, 2/2 and 1/4) were found in this study. The frequencies of IL-1RN genotypes 1/1, 1/2, 2/2 and 1/4 were 88.9%, 9.0%, 0.5% and 1.6% in patients with chronic hepatitis B respectively, while were 81.1%, 16.9%, 0.4% and 1.6% respectively in controls. The frequencies of genotype1/2 and IL-1RN allele 2 in patients with chronic hepatitis B were lower than those in controls (P=0.016 and P=0.029, respectively). CONCLUSION: There is an association between polyrnorphisms of the promoter region -511C/T of IL-1B and IL-1RN intron 2 and chronic hepatitis B virus infection. SubJects with IL-1RN 2 may be resistant to HBV infection, and IL-1B(-511) geNotype CC is closely related with HBV-DNA replication, which gives some new clues to the study of pathogenesis of chronic hepatitis B.     

Cross-linking of the beta-glucan receptor on human monocytes results in interleukin-1 receptor antagonist but not interleukin-1 production

The beta-glucan receptor, found on monocytes and neutrophils, binds glucose polymers derived from fungi. Ligands for the receptor have various immunomodulatory effects, including increased microbicidal killing activity. We have investigated the effect of beta-glucans on the production of interleukin-1 (IL-1) and its naturally occurring inhibitor, the IL-1 receptor antagonist (IL-1Ra). Particulate beta- glucan induced IL-1Ra production from human peripheral blood mononuclear cells (PBMC) but did not stimulate IL-1 beta synthesis or gene expression in these same cells. Monomeric (soluble) beta-glucan did not induce IL-1Ra production. However, when preincubated with PBMC, monomeric beta-glucan significantly (P < .01) reduced particulate beta- glucan induction of IL-1Ra by 40%, suggesting that crosslinking of beta- glucan receptors is required for induction of IL-1Ra. In support of this, monomeric beta-glucan immobilized on plastic surfaces stimulated IL-1Ra production. Vitamin D3, which increases the functional capacity of beta-glucan receptors, increased IL-1Ra production induced by particulate beta-glucan, whereas dexamethasone suppressed IL-1Ra synthesis. Because of their differential effects on cytokine production, beta-glucans may be used to therapeutic advantage in the diseases in which IL-1 is implicated.     

Lack of association between an interleukin-1 receptor antagonist gene polymorphism and ulcerative colitis.

BACKGROUND: Recently, the association of a polymorphism in the gene coding for the anti-inflammatory cytokine interleukin-1 receptor antagonist with ulcerative colitis has been reported. This was interpreted as a possible genetic predisposition for severity of the inflammatory response. AIMS: To examine this polymorphism in a southern German population. SUBJECTS: The study included 234 healthy controls, 57 patients with ulcerative colitis, including 31 patients with pancolitis, 44 first degree healthy relatives of patients with ulcerative colitis, and 65 patients with Crohn's disease. METHODS: Genotypes were determined by a polymerase chain reaction amplification of the intron 2 fragment harbouring a variable number of tandem repeat nucleotide sequences. Amplification products were separated on a 2% agarose gel. RESULTS: The allele frequency for allele 2 was 27% in healthy controls, 28% in Crohn's disease, and 21% in patients with ulcerative colitis. The same allele frequency (21%) was found in a subgroup of patients with ulcerative colitis affecting the whole colon. Thus for allele 2 as well as for all other alleles, genotypes, or carriage rates no significant differences were found compared with controls. All allele frequencies in the control population were similar to those in earlier studies. CONCLUSIONS: No association of a polymorphism in the interleukin-1 receptor antagonist gene with ulcerative colitis could be identified in this southern German population. The findings of an earlier study reporting an increased frequency of allele 2, particularly in patients with pancolitis, could not be confirmed.     

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms in ankylosing spondylitis

OBJECTIVE: Since ulcerative colitis and Crohn's disease, which are associated with ankylosing spondylitis (AS), have been found to be variably associated with the IL-1B and the IL-1RN genes encoding interleukin-1beta (IL-1beta) and the interleukin-1 receptor antagonist (IL-1ra), we have investigated whether these polymorphisms in IL-1B and IL-1RN are also involved in AS. METHODS: DNA was isolated from peripheral blood of 106 patients with AS and 104 healthy controls. All patients and controls were Dutch Caucasians. Bi-allelic polymorphisms at positions +3,953 and -511 in the IL-1B gene, and a penta-allelic polymorphism in intron 2 of the IL-1RN gene were studied by polymerase chain reaction-based methods. RESULTS: Allele IL-1RN*2 was significantly increased in AS (odds ratio=1.60; 95% confidence interval=1.20-2.80; P=0.031) compared with healthy controls, and independent from the polymorphism in loci IL-1B-511 and IL-1B+3,953. No significant associations were found between AS and the IL-1B-511 or IL-1B+3,953 polymorphisms. CONCLUSION: Similar to other chronic inflammatory diseases, AS is associated with the IL-1RN*2 allele. Further studies are necessary to determine the biological significance of these findings in relation to susceptibility or severity of the disease.     

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphisms in rheumatoid arthritis

The purpose of this study was to evaluate if IL-1beta (IL-1beta promoter and IL-1beta exon 5) and IL-1receptor antagonist (IL-1Ra) gene polymorphisms act as markers of susceptibility to or severity of RA. The study included 104 RA patients and 103 normal controls. No significant difference was observed in the cytokine allelic frequencies of IL-1beta promoter and IL-1beta exon 5 between patients with RA and healthy controls. In addition, there was no significant association in the cytokine carriage rates of I and II allele of IL-1Ra between RA patients and healthy controls. In contrast, the IV allele of IL-1Ra was significantly increased in RA patients with low inflammatory activity (P=0.03). This study indicated that allelic frequency and carriage rate of IL-1beta (IL-1beta promoter and IL-1beta exon 5) and IL-1Ra (I and II allele) do not differ significantly between normal controls and RA patients in Taiwan. However, the carriage rate of IV allele of IL-1Ra was high in the RA patients with low inflammatory activity.     

Localization of interleukin-1 receptor antagonist mRNA in rat brain.

Interleukin-1 (IL-1) is an inflammatory peptide hormone, with potent neuroendocrine effects. IL-1 stimulates the central nervous system production of corticotropin-releasing hormone (CRH), growth hormone (GH), thyroid-stimulating hormone (TSH), and somatostatin, and inhibits the secretion of prolactin and luteinizing hormone (LH). Interleukin-1 receptor antagonist (IL-1ra) is a novel cytokine, recently purified, characterized, and cloned. IL-1ra is a pure endogenous antagonist of IL-1:IL-1 function is modulated not only by local levels of IL-1, but also by the levels of IL-1ra. We have localized by in situ hybridization histochemistry IL-1ra mRNA in rat brain, in areas of importance to neuroendocrine function, such as the paraventricular nucleus (PVN) of the hypothalamus, hippocampus, as well as cerebellum. These findings indicate that IL-1ra is produced in brain in areas of relevance to the regulation of neuroendocrine function and suggest that IL-1ra may modulate the neuroendocrine effects of IL-1.