Presence Of Interleukin-1 Alpha Research Articles

Keratinocyte-derived growth factors play a role in the formation of hypertrophic scars.

In predisposed individuals, wound healing can lead to hypertrophic scar or keloid formation, characterized by an overabundant extracellular matrix. It has recently been shown that hypertrophic scars are accompanied by abnormal keratinocyte differentiation and proliferation, and significantly increased acanthosis, compared with normal scars. This study addressed the question of whether the development of normal and hypertrophic scars is regulated by differences in the growth factor profiles of both the epidermis and the dermis. The presence of interleukin-1alpha (IL-1alpha), IL-1beta, tumour necrosis factor-alpha (TNF-alpha), platelet-derived growth factor (PDGF), transforming growth factor-beta1 (TGF-beta1), and basic fibroblast growth factor (bFGF) was investigated in biopsies taken from breast reduction scars at 3 and 12 months following surgery. The samples were analysed by immunohistological methods and categorized as scars that remained hypertrophic (HH), became normal (HN) or remained normal after 12 months (NN). The epidermal expression of IL-1alpha was significantly increased in NN scars compared with HN and HH scars 3 and 12 months following operation, whereas the dermal expression showed no difference. PDGF was significantly increased in the dermis of normal scars after 3 months and in both the epidermis and the dermis of hypertrophic scars after 12 months. IL-1beta, TNF-alpha, TGF-beta and bFGF showed no differences. It is hypothesized that impaired production of keratinocyte-derived growth factors, such as IL-1alpha, leads to a decrease in the catabolism of the dermal matrix, whereas augmented epidermal PDGF production leads to increased formation of the dermal matrix in hypertrophic scars. These observations support the possibility that the epidermis is involved in preventing the formation of hypertrophic scars.

Regulation of manganese superoxide dismutase in glomerular epithelial cells: Mechanisms for interleukin 1 induction

Reactive oxygen species have been implicated as mediators of tissue injury in glomerular inflammation. The expression of the antioxidant enzyme, manganese superoxide dismutase (MnSOD), was examined in primary cultures of rat glomerular epithelial cells (GEC) in response to inflammatory mediators. The results demonstrate that GEC respond to interleukin-1 (IL-1) and bacterial lipopolysaccharride (LPS) with an increase in MnSOD steady-state mRNA levels. The IL-1 alpha-mediated induction of MnSOD mRNA levels was both time- and dose-dependent. Maximal levels approximately 40-fold above controls, were observed at 12 hours with 2 ng/ml of IL-1 alpha. MnSOD protein levels were also markedly elevated by IL-1 alpha. The induction of MnSOD mRNA by IL-1 alpha required de novo transcription as well as some degree of protein synthesis. To elucidate the potential intracellular signal that mediates IL-1 alpha-dependent MnSOD expression, three classical signaling pathways were examined. We found no evidence that MnSOD induction by IL-1 alpha is mediated by either the cyclooxygenase or lipoxygenase pathway or via activation of protein kinase C. Based on the presence of IL-1 alpha in several forms of glomerular inflammation, the observed increase in MnSOD expression by this immunoregulatory cytokine must have an important role in the antioxidant defense of glomerular epithelial cells.

Interleukin-1 alpha- and beta-, interleukin-6- and tumour necrosis factor-alpha-like immunoreactivities in chronic granulomatous skin conditions.

Paraformaldehyde-fixed tissue of chronic granulomatous skin conditions, such as cutaneous leishmaniasis, granuloma annulare, leprosy and hidroadenitis, was investigated for the presence of interleukin-1 alpha-, interleukin-1 beta-, interleukin-6- and tumour necrosis factor-alpha-like immunoreactivities among the cellular infiltrates. There was a weak to strong cytoplasmic labelling of plasma cells for interleukin-6 and tumour necrosis factor-alpha at the periphery of the granulomatous mass and around the skin appendages. The interleukin-6-like immunoreactivity seemed to be correlated with the coarseness of the chromatin material of the cells, being more intense with coarse chromatin. The cytoplasmic labelling for interleukin-1 alpha and interleukin-1 beta in the plasma cells was less intense. Epitheloid, Langhans' giant cells and small round cells exhibited a weak to moderate cytoplasmic labelling for interleukin-1 alpha and interleukin-1 beta, whereas the staining intensity for interleukin-6 and tumour necrosis factor-alpha was weak to strong. In addition, there was staining of the stroma in the centre of granuloma with antisera against interleukin-1 alpha, interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha. This area contained few cells, suggesting that the granuloma was in a resolution process. A contribution of interleukin-6 and tumour necrosis factor-alpha to the granulomatous reaction, at least during the maintenance period, is suggested by the occurrence of these cytokines in the skin conditions studied. The findings are also consistent with a suggested role of B cells in the late stages of the granulomatous reaction. In addition, they are in line with the reported declining role of interleukin-1 in the maintenance of granuloma.

Expression and release of interleukin-1 by human glioblastoma cells in vitro and in vivo.

The present study demonstrates interleukin-1 (IL-1) production by human glioblastoma cells both in vitro and in vivo. The presence of IL-1 alpha and IL-1 beta transcripts was analyzed in 4 cell lines. IL-1 alpha mRNA was expressed constitutively in one cell line whereas constitutive IL-1 beta mRNA could not be detected in any of the cell lines. IL-1 alpha transcripts could be induced with phorbol myristate acetate (PMA) or PMA plus lipopolysaccharide (LPS) in 2 of 4 cell lines and IL-1 beta mRNA in 2 of 4 cell lines. Culture fluid from these cell lines was tested for the presence of IL-1 using a specific radio-immuno-assay for either IL-1 alpha or IL-1 beta. In agreement with the results on RNA, one of 4 cell lines was found to constitutively produce IL-1 alpha but not IL-1 beta. After treatment with PMA and LPS, IL-1 alpha was detected in the culture fluid from two other lines and IL-1 beta in the medium from three lines. That the IL-1 produced by these cell lines was biologically active was confirmed in a two step thymocyte proliferation assay. IL-1 like activity was detected in all samples that were positive in the radio-immuno-assay. Finally, immunohistological analysis on fresh frozen tumour sections provided evidence for IL-1 production by glioblastoma cells in vivo. Fourteen out of 28 glioblastomas were stained with an anti-IL-1 alpha monoclonal antibody while none of them was stained with an anti-IL-1 beta antibody.

Regulation of the synthesis and secretion of transferrin and cyclic protein-2/cathepsin L by mature rat Sertoli cells in culture.

While numerous studies have examined the response of immature rat Sertoli cells to specific hormones and growth factors, the regulation of mature cells in vitro has not been well examined because highly purified cells have been difficult to isolate. We now describe a detailed method for isolating Sertoli cells from mature (> 60 days of age) rats and generating primary cultures of these cells greater than 90% in purity. We demonstrate that cell density, hormones, and growth factors regulate the synthesis or secretion of two Sertoli cell products, transferrin and Cyclic Protein-2 (CP-2)/cathepsin L. Cell density modulated the response of mature Sertoli cells to some hormones; insulin (at 10 micrograms/ml) and epidermal growth factor (EGF) acted synergistically to stimulate transferrin synthesis by 80% when cells were cultured at a density of 1.65 x 10(5) cells/cm2 but had no effect on transferrin synthesis by cells cultured at 1.46 x 10(5) cells/cm2. A mixture of FSH, retinol, and testosterone increased transferrin synthesis by 30% at both cell densities, and this stimulation was independent of the effect of EGF and insulin. CP-2/cathepsin L synthesis was significantly stimulated by increased cell density. FSH, retinol, and testosterone also stimulated CP-2/cathepsin L synthesis by 30%; however, this stimulation just missed being statistically significant. Finally, we demonstrated that secretion of transferrin and CP-2 was reduced when cells were cultured in the presence of interleukin-1 alpha, a cytokine synthesized by Sertoli cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Suspected distinct activation pathways of human lymphocytes induced by antilymphocyte globulin and anti-CD3 monoclonal antibody result in different secretion of hematopoietic colony-stimulating activities.

We evaluated the activation sequence of peripheral blood lymphocytes from healthy donors using different mitogens, including antilymphocyte globulin (ALG), anti-CD3 monoclonal antibody (OKT3), and phytohemagglutinin (PHA). Blood mononuclear cells stimulated by ALG, OKT3 and PHA incorporated 3H-thymidine in the same way. When enriched T cells were tested in the presence of interleukin-1 alpha (0 to 100 U/ml, incorporation of 3H-thymidine was greater in those cells stimulated by ALG than by PHA. OKT3 did not activate enriched T cells. Thymidine incorporation was reduced to less than 50% of maximum concentrations by the addition of 10(-7) mol/1,25-dihydroxyvitamin D3 (vit D3) in PHA- or OKT3-activated cells. However, the inhibitory effect of vit D3 was not apparent in ALG-activated cells. Production of granulocyte-macrophage colony-stimulating factor and interleukin-3 by lymphocytes upon activation was consistently higher when cells were treated with ALG or PHA than with OKT3. Taken together, the data indicate that there appear to be distinct functional mechanisms between ALG- and OKT3-induced lymphocyte activation that lead to characteristic immunohematologic events.

Interleukin-1 alpha-induced changes in androgen and cyclic adenosine 3',5'-monophosphate release in adult rat Leydig cells in culture.

Interleukin-1 (IL-1) has been proposed as a paracrine regulator of testicular function. The effect of this cytokine on adult rat Leydig cells in primary culture was investigated. Interstitial cells were purified on a two-step Percoll gradient and cultured in the presence or absence of recombinant human IL-1 alpha (IL-1 alpha). The presence of IL-1 alpha in the culture media resulted in a dose-dependent increase in 24-h basal androgen release (half-maximal effective concentration = 40-50 U/ml). The stimulatory effect of IL-1 alpha peaked on days 3 and 4, and was often still significant after 6 days of culture. Removal of IL-1 alpha was followed by a return of basal androgen release to control levels within 3 days. In contrast, cells treated with IL-1 alpha (100 U/ml) for 3 days released significantly less androgen (per 4 h) in response to 1-100 ng LH/ml than control cells. A similar inhibitory effect on the response to dibutyryl cAMP and pregnenolone was observed. Under basal conditions, IL-1 alpha-treated cells released significantly more cAMP than did control cells. In contrast, the increase in cAMP release seen with LH-stimulated cells was significantly inhibited by treatment with IL-1 alpha. These results suggest that IL-1 alpha has a dual effect on adult rat Leydig cells in culture. It stimulates basal but inhibits LH-induced androgen release with parallel changes in cAMP levels. An additional inhibitory effect appears to lie at the level of the 17 alpha-hydroxylase/C17-20 lyase enzyme.

Analysis of the catabolism of aggrecan in cartilage explants by quantitation of peptides from the three globular domains

A method has been developed for the production, isolation, and quantitation of 15 marker peptides from the three globular domains (G1, G2, and G3) and the interglobular domain of bovine aggrecan (aggregating cartilage proteoglycan). Three of the peptides are from G1, two are from the interglobular domain, four are from G2, and six are from G3. The method involves separation of tryptic peptides by sequential anion-exchange, cation-exchange, and reversed-phase high performance liquid chromatography and quantitation by absorbance at 220 nm. The values obtained (peak area per microgram of core protein) were a function of the molar yield and also the size and aromatic residue content of individual peptides. This procedure has been applied to aggrecan purified from fresh calf articular cartilage and to aggrecan isolated from the medium and tissue compartments of cartilage explant cultures, maintained in basal medium for 15 days without and with interleukin-1 alpha. These analyses indicate that aggrecan which is released into explant medium has a reduced content of the G1 domain, but has a normal content of the G2 domain, the COOH-terminal region of the interglobular domain, and also the G3 domain. On the other hand, aggrecan which is retained by the cartilage during 15 days of culture has a normal content of G1, interglobular domain, and G2 domains, but, in the presence of interleukin-1 alpha, it has a reduced content of the G3 domain. The percentage of medium molecules which retained the G1 domain was higher in control cultures (about 35%) than in interleukin cultures (about 20%), and this was consistent with the relative aggregability of these samples. Taken together these results suggest that catabolism of aggrecan in articular cartilage involves a specific proteolysis of the core protein at a site which is within the interglobular domain and NH2-terminal to the sequence LPGG. This process occurs in control cultures but is accelerated by the addition of interleukin-1 alpha. Degraded molecules which lack the G1 domain are released preferentially into the medium; however, these molecules carry both the G2 and G3 domains, indicating that these domains do not confer strong matrix binding properties on aggrecan. The method described here for the isolation of peptides from bovine aggrecan should have wide application to structural and biosynthetic studies on this molecule in species such as human and rat, since many of the marker peptides are from highly conserved regions of the aggrecan core protein.