Chromosomal localization of murine interleukin-1 alpha and beta genes

DNA analyses of mouse X Chinese hamster somatic cell hybrids and of recombinant inbred mouse strains have previously shown that the interleukin-1 alpha and beta genes are tightly linked on murine chromosome 2, approximately 4.7 cM distal to beta-2-microglobulin. In this study, using in situ chromosome hybridization, we show that the two interleukin-1 genes are located in the F region of murine chromosome 2 and discuss this physical map position in relation to conserved genetic linkage groups.     

Differential biological activities of human interleukin-1 alpha and interleukin-1 beta

We examined the biological effects induced by both human recombinant interleukin-1 alpha (IL-1 alpha) and beta (IL-1 beta) in five different cell types of human, rat and mouse origin. IL-1 alpha and beta preparations were standardized in terms of biological activity in the EL-4/CTLL bioassay and, in parallel, employed to stimulate PGE2 secretion in human fibroblasts, mesangial cells (MC), C57B1/6 mouse MC, DBA/2 mouse macrophages and Sprague Dawley rat MC. In addition, the co-mitogenic effects of IL-1 alpha and beta were determined in freshly prepared Sprague Dawley rat thymocytes. No significant differences in IL-1 alpha and beta concentration dependent PGE2 production were detectable in the different cell types (MC, fibroblasts and macrophages) of human or mouse origin. Incubation of Sprague Dawley rat MC with both IL-1 alpha and beta resulted in a concentration dependent production of PGE2. However, in contrast to mouse or human MC the potency of IL-1 beta to induce PGE2 in Sprague Dawley rat MC was 26-fold higher compared to IL-1 alpha. In addition, the potency of IL-1 beta to enhance co-stimulated proliferation of Sprague Dawley thymocytes was 200-fold higher than that of equal biological activities of IL-1 alpha. When we tested the additive effects on Sprague Dawley cells, increasing IL-1 beta concentrations added to a fixed IL-1 alpha concentration resulted in a cumulative rise in both, PGE2 secretion by MC and thymocyte proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Expression of interleukin-1 alpha, tumor necrosis factor alpha and interleukin-6 genes in astrocytes under ischemic injury

Astrocytes form an integral part of the blood brain barrier and are the first cell type in the central nervous system to encounter insult if there is an ischemic attack. The immunologic reaction of astrocytes to an ischemic insult would be affective to the subsequent responses of other nerve cells. We previously showed that ischemia caused an increase in the levels of interleukin 1alpha (IL-1alpha), tumor necrosis factor alpha (TNF alpha), and interleukin 6 (IL-6) in the culture medium of mouse cerebral cortical astrocyte. We did not have evidence on the source of these cytokines. This study aimed to investigate the expressions of these cytokine mRNAs in the astrocytes under ischemia. Results demonstrated that ischemia could induce necrosis and apoptosis in astrocytes. By using the RT-PCR method, we demonstrated for the first time that the mRNA levels of IL-1alpha, TNF alpha and IL-6 in normal astrocyte was very low, but their expressions could be induced quickly under ischemia. These cytokines might be interactive as indicated by the difference in time course of their expressions, with IL-1alpha being the earliest and IL-6 being the latest. The result provided some understanding of the induction and progression of these immunologic responses in astrocytes under ischemia. It also supported our previous findings that astrocytes contributed to the cytokines released under ischemia.     

Interleukin-1 alpha and beta induce interleukin-1 beta gene expression in human dermal fibroblasts

The ability of the two forms of interleukin-1, IL-1 alpha and IL-1 beta, to induce IL-1 beta gene expression in human skin fibroblasts was studied in vitro, using Northern blot hybridization. Both recombinant IL-1 alpha and IL-1 beta caused a dramatic increase in IL-1 beta mRNA levels, IL-1 alpha being more efficient than IL-1 beta. Blockage of the prostaglandin synthesis by indomethacin reduced the basal level of IL-1 beta mRNA in control cultures and decreased also the stimulatory effect exerted by both IL-1s on IL-1 beta gene expression. These data suggest that IL-1 and prostaglandin (mainly PGE2) may act synergistically to stimulate IL-1 gene expression in dermal fibroblasts, contributing as a local amplifier system to the alterations of connective tissue in inflammatory processes.     

Relationships between serum IGF-1, IGFBP-2, interleukin-1beta and interleukin-6 in inflammatory bowel disease

AIMS: To study the relationships between serum IGF-1, IGFBP-3 and IGFBP-2 and interleukin (IL)-1beta and IL-6 in inflammatory bowel disease (IBD). METHODS: Thirty-seven patients (18 males, 19 females, aged 8.8-26.1 years) with IBD (Crohn's disease, CD, n = 17, and ulcerative colitis, UC, n = 20) were studied. Patients were in relapse or remission according to established criteria. Serum IGF-1, IGFBP-3, IGFBP-2, IL-1beta and IL-6 levels were determined in patients and 15 healthy controls (aged 8.2-19.0 years). RESULTS: IGF-1 levels were lower in patients with CD in relapse compared with controls (p < 0.05). IGFBP-2 levels were higher in CD in relapse compared with other groups (all p < 0.05). In CD and UC patients (n = 37), IGF-1 levels were inversely correlated with the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). IGFBP-2 levels correlated positively with ESR and IL-1beta. IL-6 levels correlated positively with ESR and CRP. IL-1beta levels were elevated in CD in relapse compared to controls (p < 0.05) and were higher in UC in relapse than in other groups (all p < 0.05). In combined CD/UC patients in relapse (n = 20), IL-1beta levels were higher (p < 0.05) in patients with recto-sigmoiditis (n = 5) than in other patients. CONCLUSIONS: IGF-1, IGFBP-2 levels were related to IL levels, disease activity and anatomical distribution, consistent with active inflammation modifying the IGF-IGFBP system, possibly relevant to disturbance of growth.     

Circulating integrins: alpha 5 beta 1, alpha 6 beta 4 and Mac-1, but not alpha 3 beta 1, alpha 4 beta 1 or LFA-1.

The alpha 5 beta 1, alpha 6 beta 4 and Mac-1 integrins all participate in the endocytotic cycle. By contrast, alpha 3 beta 1, alpha 4 beta 1 and LFA-1 do so much more slowly, or not at all, in the cell lines examined. This indicates that the alpha-chains appear to determine whether an integrin cycles or not, and that alpha 5 beta 1, alpha 6 beta 4 and Mac-1 can be brought to the leading edge of a moving cell by endocytosis and recycling.     

Stimulation of ACTH release by human interleukin-1 beta, but not by interleukin-1 alpha, in conscious, freely-moving rats

Ever since two distinct molecules of human interleukin-1 (termed interleukin-1 alpha and interleukin-1 beta) were cloned, sequenced and expressed, it has been a matter of investigation whether these two forms of interleukin-1 possess an identical spectrum of biological activities. Our current studies of interleukin-1 and its involvement in the hypothalamic-pituitary-adrenal axis have indicated that there is a clear-cut differential response to interleukin-1 alpha and interleukin-1 beta. The intravenous injection of human recombinant interleukin-1 beta significantly increased the plasma levels of adrenocorticotropic hormone in a dose-related manner, whereas interleukin-1 alpha did not. This observation suggests for the first time that the two members of the interleukin-1 family may have a different spectrum of biological actions.     

Central activation of thermogenesis and fever by interleukin-1 beta and interleukin-1 alpha involves different mechanisms

Interleukin-1 exists in two forms (alpha and beta) which are assumed to act on the same receptor. Both forms of the molecule stimulated fever and thermogenesis in the rat when injected into the brain, but interleukin-1 beta was more effective, and combined injection of alpha and beta elicited additive responses. The actions of interleukin-1 beta were inhibited by pretreatment of the animals with either a receptor antagonist or monoclonal antibody to corticotrophin releasing factor. The effects of interleukin-1 alpha were unaltered by these treatments. The results indicate that brain corticotrophin releasing factor mediates thermogenesis and fever induced by interleukin-1 beta but not by interleukin-1 alpha.     

LL-Z1271alpha: an interleukin-1beta production inhibitor

LL-Z1271alpha, a fungal metabolite, dose-dependently inhibited interleukin-1beta (IL-1beta) production in lipopolysaccharide (LPS)-stimulated human whole blood. Oral administration of LL-Z1271alpha to LPS-challenged mice caused significant lowering in the IL-1beta levels in peritoneal cavity. Data presented suggest that LL-Z1271alpha inhibits IL-1beta production by a novel mechanism as the inhibitory activity was not due to effects on caspase-1 (IL-1beta converting enzyme), the ATP-induced release mechanism or a lysosomotrophic effect.     

Cloning of rabbit interleukin-1 beta: differential evolution of IL-1 alpha and IL-1 beta proteins

We have cloned the rabbit IL-1 beta cDNA, which encodes a 268 amino acid precursor similar in length to other sequenced IL-1 precursors. Comparison of all published IL-1 alpha and IL-1 beta sequences respectively indicates that the IL-1 alpha gene family is evolving faster than the IL-1 beta family, and that the two genes diverged approximately 270 million years ago. Surprisingly, there are differences in the regions preferentially conserved within the two families. The IL-1 alpha family is most conserved at the amino terminus whereas the IL-1 beta family is most conserved in the carboxy-terminal half. This is despite the fact that the carboxy-terminal half encodes the active portion of both molecules and would be expected to adopt a similar beta-sheet structure in IL-1 alpha as in the published X-ray structure of mature IL-1 beta. These findings suggest that differences in the function and properties of the IL-1 alpha and IL-1 beta precursor molecules may have been conserved. These differences may therefore provide an explanation for the existence of two IL-1 molecules.     

The dynamics and mechanisms of interleukin-1alpha and beta nuclear import

Pro-inflammatory members of the interleukin-1 (IL-1) family of cytokines (IL-1α and β) are important mediators of host defense responses to infection but can also exacerbate the damaging inflammation that contributes to major human diseases. IL-1α and β are produced by cells of the innate immune system, such as macrophages, and act largely after their secretion by binding to the type I IL-1 receptor on responsive cells. There is evidence that IL-1α is also a nuclear protein that can act intracellularly. In this study, we report that both IL-1α and IL-1β produced by microglia (central nervous system macrophages) in response to an inflammatory challenge are distributed between the cytosol and the nucleus. Using IL-1-β-galactosidase and IL-1-green fluorescent protein chimeras (analyzed by fluorescence recovery after photobleaching), we demonstrate that nuclear import of IL-1α is exclusively active, requiring a nuclear localization sequence and Ran, while IL-1β nuclear import is entirely passive. These data provide valuable insights into the dynamic regulation of intracellular cytokine trafficking.     

Essential, overlapping and redundant roles of the Drosophila protein phosphatase 1 alpha and 1 beta genes

Protein serine/threonine phosphatase type 1 (PP1) has been found in all eukaryotes examined to date and is involved in the regulation of many cellular functions, including glycogen metabolism, muscle contraction, and mitosis. In Drosophila, four genes code for the catalytic subunit of PP1 (PP1c), three of which belong to the PP1α subtype. PP1β9C (flapwing) encodes the fourth PP1c gene and has a specific and nonredundant function as a nonmuscle myosin phosphatase. PP1α87B is the major form and contributes ~80% of the total PP1 activity. We describe the first mutant alleles of PP1α96A and show that PP1α96A is not an essential gene, but seems to have a function in the regulation of nonmuscle myosin. We show that overexpression of the PP1α isozymes does not rescue semilethal PP1β9C mutants, whereas overexpression of either PP1α96A or PP1β9C does rescue a lethal PP1α87B mutant combination, showing that the lethality is due to a quantitative reduction in the level of PP1c. Overexpression of PP1β9C does not rescue a PP1α87B, PP1α96A double mutant, suggesting an essential PP1α-specific function in Drosophila.     

Different patterns of interleukin-1alpha and interleukin-1beta expression in organs of normal young and old mice

The different physiological roles of interleukin-1alpha (IL-1alpha) and interleukin-1beta (IL-1beta) are not well understood, especially when considering the apparent overlap and redundancy of the two IL-1 molecules. Characterization of IL-1alpha and IL-1beta expression was performed in this study in organs from young and old mice, using immunohistochemistry and ELISA (enzyme-linked immunosorbent assay). The results indicate that organ IL-1alpha and IL-1beta display different patterns of expression: IL-1alpha is manifested more prominently in lymphoreticular organs (lungs, small intestine, spleen, liver), while IL-1beta is more evident in highly specialized and more vulnerable organs, which do not play a leading role in defense against infections and intoxication (heart, brain, skeletal muscle, kidney). This differential expression is more accentuated in old mice, possibly pointing to the special relevance of these cytokines to organ homeostasis in old age. These findings may shed new light on the physiological functions of IL-1alpha and IL-1beta, and may also lead to the development of improved therapeutic approaches, based on the specific manipulation of these cytokines.     

Genetic variation in pro-inflammatory cytokines (interleukin-1beta, interleukin-1alpha and interleukin-6) associated with the aggressive forms, survival, and relapse prediction of breast carcinoma

OBJECTIVES: Interleukin-1 (IL-1) and interleukin-6 (IL-6) are determining factors in the immune and inflammatory responses to tumors cells. Experimental data suggest that interleukin-1 and interleukin-6 play important roles in the development and progression of breast cancer. We designed a broad study to investigate the susceptibility and prognostic implications of the genetic variation in IL-1alpha, IL-1beta and IL-6 in breast carcinoma. EXPERIMENTAL DESIGN: We used the polymerase chain reaction and restriction enzyme digestion to characterize the genetic variation of IL-1alpha, IL-1beta and IL-6 in 305, unrelated Tunisian patients with breast carcinoma and 200 healthy control subjects. Associations between the genetic markers and the clinicopathological parameters, the specific overall survival rate (OVS) of breast carcinoma and the disease free-survival rate (DFS) were assessed using univariate and multivariate analyses. RESULTS: Both IL-6 (-597) GA and IL-6 (-174) GC heterozygous genotypes were found to be significantly associated with breast carcinoma (OR = 1.59, p = 0.024 and OR = 1.61, p = 0.022 respectively). A highly significant association was found between the (+3954) T allele of IL1-B gene and the aggressive phenotype of breast carcinoma as defined by the high histological grade, axillary lymph node metastasis and large tumor size. The IL-1alpha (-889) TT homozygous genotype showed a significant association with reduced disease-free survival and/or overall survival rate. The IL-1beta (+3954) TT, IL-6 (-597) GG and IL-6 (-174) GG homozygous genotypes were found to be associated with reduced DFS but not with overall survival. CONCLUSIONS: The polymorphisms in the promoter region of the IL-6 gene may represent a marker for the increased risk of breast carcinoma. Genetic variations in IL-1alpha, IL-1beta and IL-6 may predict the clinical outcome of breast carcinoma.     

Over expression of interleukin-1alpha,interleukin-1beta and interleukin-1 receptor antagonist in testicular tissues from sexually immature mice as compared to adult mice

The levels of IL-1alpha, IL-1beta and IL-1Ra were higher in homogenates of testicular tissue from sexually immature than those from mature mice. Immunohistochemical staining of testicular tissues from sexually immature and adult mice show that differentiated germ cells express higher levels of IL-1alpha compared to Sertoli cells and Leydig cells/interstitial cells. Peritubular cells of sexually immature and adult mice did not express IL-1alpha. Testicular tissue cells of adult mice showed high levels of expression of IL-1beta, mainly in the cytoplasm and nucleus of the spermatogonia and in spermatocytes. Sertoli cells and Leydig/interstitial cells were also highly stained for IL-1beta. However, peritubular cells did not express IL-1beta. On the other hand, testicular tissue cells from sexually immature mice, showed high levels of IL-1beta, mainly in spermatocytes. Spermatogonia showed low levels of IL-1beta expression. Also, high levels of IL-1beta expression were detected in Leydig/interstitial cells. Peritubular cells clearly showed IL-1beta expression. Testicular tissue cells from adult mice, showed IL-1Ra expression in spermatogonia, Sertoli and Leydig/interstitial cells. IL-1Ra expression was clearly present in the Golgi apparatus of spermatogonia and Sertoli cells. However, peritubular cells did not show IL-1Ra expression. Testicular tissue cells from sexually immature mice, also showed high levels of IL-1Ra expression mainly in the cytoplasm and nucleus of the spermatogonia and Sertoli cells. In addition, Leydig/interstitial cells and peritubular cells also expressed IL-1Ra. Our results demonstrate, for the first time, the expression of IL-1beta in germ and Sertoli cells, and IL-1Ra in Leydig/interstitial cells of testicular tissues from adult and sexually immature mice, under in vivo conditions. In addition, the relative elevated levels of the IL-1 system in the testis of immature mice compared to mature mice may indicate its involvement in the spermatogenesis.     

Associations of interleukin-6 with interleukin-1beta, interleukin-8 and macrophage inflammatory protein-1beta in midlife women

Objective: The aim of the present study was to determine the associations of interleukin (IL)-6 with other cytokines and chemokines and to compare these associations in peri- and postmenopausal women. Methods: Ninety-nine perimenopausal and 92 postmenopausal women were enrolled in this study. Serum concentrations of IL-6, IL-1β, IL-2, IL-4, IL-5, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17, tumor necrosis factor (TNF)-α, interferon γ, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage (GM)-CSF, macrophage inflammatory protein (MIP)-1β and monocyte chemotactic protein (MCP)-1 were measured simultaneously using a multiplexed cytokine assay. Results: Among the 17 cytokines, IL-6, IL-1β, IL-5, IL-7, IL-8, IL-10, MCP-1 and MIP-1β were detected in serum in more than 50% of the women. Serum levels of IL-4 and MCP-1 in postmenopausal women were significantly higher than those in perimenopausal women. Serum IL-6 concentrations showed significant and positive correlations with serum concentrations of IL-1β, IL-8, MIP-1β, IL-7 and MCP-1 in women regardless of menopausal status, and these correlations were still significant after adjustment for age and body mass index. Conclusion: Serum IL-6 concentration was found to be closely associated with serum concentrations of IL-1β, IL-8, MIP-1β, IL-7 and MCP-1 in women regardless of menopausal status, suggesting that these cytokines act in concert with the progression of several symptoms and various diseases.     

Multiple binding sites in collagen type I for the integrins alpha1beta1 and alpha2beta1

Integrins alpha(1)beta(1) and alpha(2)beta(1) are two major collagen receptors on the surface of eukaryotic cells. Binding to collagen is primarily due to an A-domain near the N terminus of the alpha chains. Previously, we reported that recombinant A-domain of alpha(1)beta(1) (alpha(1)A) had at least two affinity classes of binding sites in type I collagen (Rich, R. L., et al. (1999) J. Biol. Chem. 274, 24906-24913). Here, we compared the binding of the recombinant A-domain of alpha(2)beta(1) (alpha(2)A) to type I collagen with that of alpha(1)A using surface plasmon resonance and showed that alpha(2)A exhibited only one detectable class of binding sites in type I collagen, with a K(D) of approximately 10 microm at approximately 3 binding sites per collagen molecule. We further demonstrated that alpha(1)A and alpha(2)A competed with each other for binding to type I collagen in enzyme-linked immunosorbent assay (ELISA), suggesting that the binding sites in collagen for the two A-domains overlap or are adjacent to each other. By using rotary shadowing, the complexes of alpha(1)A- and alpha(2)A-procollagen were visualized. Morphometric analyses indicated three major binding regions (near the N terminus, in the central part, and near the C terminus) along the type I procollagen molecule for both A-domains. The positions of the respective binding regions for alpha(1)A and alpha(2)A were overlapping with or adjacent to each other, consistent with the ELISA results. Analysis of the sequences of type I collagen revealed that GER or GER-like motifs are present at each of the binding regions, and notably, the central region contains the GFOGER sequence, which was previously identified as a high affinity site for both alpha(1)A and alpha(2)A (Knight, C. G., et al. (2000) J. Biol. Chem. 275, 35-40). Peptides containing GLOGERGRO (peptide I, near the N terminus), GFOGERGVQ (peptide II, central), and GASGERGPO (peptide III, near the C terminus) were synthesized. Peptides I and II effectively inhibited the binding of alpha(1)A and alpha(2)A to type I collagen, while peptide III did so moderately. The N-terminal site in type I collagen has the sequence GLOGER in all three chains. Thus, it seems that peptide I represents a newly discovered native high affinity site for alpha(1)A and alpha(2)A.