Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05231 (interleukin-6)
 23,907 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anorexia nervosa is a serious eating disorder characterized by extreme weight loss and abnormalities of the neuroendocrine and immune systems. To determine the potential role of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and transforming growth factor-beta (TGF-beta) in anorexia nervosa, serum concentrations of these cytokines were measured in patients with anorexia nervosa during starvation and after weight gain. Serum IL-6 and TGF-beta concentrations were both significantly elevated during starvation and returned to levels comparable to those of normal-weight controls by the end of therapy. In contrast, serum TNF-alpha levels were undetectable in all patients and controls. Cytokines may play previously unsuspected roles in anorexia nervosa and its complications.
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PMID:Role of interleukin-6 and transforming growth factor-beta in anorexia nervosa. 789 47

The effects of methylprednisolone and cyclophosphamide were examined in a murine model of lupus nephritis (MRL-1pr/1pr). Animals were assigned to four groups at 12 weeks of age. Mice in the control group received intraperitoneal saline solution either daily or weekly. Animals in the low-dose methylprednisolone (MPLD) group received 6 mg/kg/day intraperitoneal methylprednisolone; those in the high-dose methylprednisolone (MPHD) group received 12 mg/kg/day intraperitoneal methylprednisolone. Animals in the cyclophosphamide group received 50 mg/kg/wk intraperitoneal cyclophosphamide. Animals surviving to 24 weeks were examined. MPHD and cyclophosphamide treatments were associated with maintenance of normal glomerular filtration rates and the development of only minimal proteinuria. However, detailed morphometric evaluation of the glomerulus revealed glomerular enlargement and mesangial matrix expansion in both groups. Unlike MPHD-treated mice, cyclophosphamide-treated animals demonstrated a marked reduction in the number of osmophilic dense deposits along the glomerular capillary walls. MPLD had little effect on function, despite significant reductions in cell proliferation and anti-double-strand DNA antibodies. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels were dramatically increased in plasma of control animals. Treatment with methylprednisolone and cyclophosphamide dramatically reduced TNF-alpha but not IL-6. Treatment also reduced renal IL-1 beta, TNF-alpha and transforming growth factor-beta mRNA levels compared with untreated mice. Despite minimal serologic activity and preservation of renal function, neither cyclophosphamide nor methylprednisolone was able to completely suppress disease activity, as measured by increased cytokine production and glomerular structural injury. The inability of treatment to reduce IL-6 levels may explain the resistance to treatment in this model.
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PMID:Modulation of glomerular structure and function in murine lupus nephritis by methylprednisolone and cyclophosphamide. 793 Aug 70

Human immunodeficiency virus infection is associated with the development of focal segmental glomerulosclerosis (FSGS). The majority of these patients with renal disease, however, are also cocaine abusers, but it is unknown what role cocaine may play in the development of focal segmental glomerulosclerosis. We undertook the present study to determine in vitro whether cocaine can modulate mesangial cell (MC) proliferation, a process believed to be a precursor to the development of glomerulosclerosis, either directly or indirectly via interaction with macrophages (M phi). Cocaine alone was not found to alter significantly either MC number or MC [3H]thymidine incorporation. However, when MC were incubated with secretory products collected from M phi preincubated with standard medium or medium containing cocaine, MC proliferation was found to be significantly enhanced with secretory products from M phi preincubated with cocaine in both serum-free (P < .001) and serum-stimulated conditions (P < .001). The effect of cocaine was found to be concentration-related. Pretreatment of macrophage secretory products from cocaine-treated M phi with neutralizing antibodies to transforming growth factor-beta significantly augmented the mitogenic effect of cocaine macrophage secretory products, and neutralizing antibodies to interleukin-6 significantly attenuated this effect. Direct incubation of MC with transforming growth factor-beta and interleukin-6 caused significant suppression and augmentation of MC proliferation, respectively. These data suggest that cocaine can modulate MC proliferation via interaction with M phi and that interleukin-6 and transforming growth factor-beta participate in this modulating effect. These results support a potential role for cocaine in the development of focal segmental glomerulosclerosis in patients with human immunodeficiency virus infection.
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PMID:Cocaine interacts with macrophages to modulate mesangial cell proliferation. 796 30

The development of clinically frank malignant melanomas in humans is thought to evolve over decades in a stepwise process of progression. By analogy with certain other adult cancers, eg, colorectal carcinomas, alterations in expression or function of a number of different suppressor genes might be expected to be involved in this process. This could lead to loss of expression of a number of different negative growth controls. Evidence is reviewed implicating the presence of putative suppressor genes for the melanocytic lineage located on chromosomes 9p21, 6q, and 1p. In addition, there is evidence suggesting a contribution for the p53 and NF1 tumor-suppressor genes, and the nm23 metastasis-suppressor gene, in melanoma development or progression. Additional possible suppressor genes include those encoding manganese superoxide dismutase, and possibly c-kit. An accumulation of such alterations may be responsible for the progressive loss of responsiveness to several independent growth inhibitors for melanocytes or early stage melanomas, including interleukin-6, transforming growth factor-beta, and oncostatin M. They may also be responsible for some aspects of the production of direct acting autocrine growth factors or production of angiogenesis stimulating factors, or both, by melanoma cells. The acquisition of resistance to several growth inhibitors and the multiplicity of putative suppressor gene alterations (combined with the production of multiple autocrine and paracrine growth factors) may be necessary for the evolution of nondividing single melanocytes resident in the epidermis into highly proliferative and metastatic melanomas capable of growing multicellularly in ectopic organ sites.
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PMID:Cytokines, growth factors and the loss of negative growth controls in the progression of human cutaneous malignant melanoma. 801 99

Metabolism of dehydroepiandrosterone sulfate (DHEAS) to dehydroepiandrosterone (DHEA) occurs within specific anatomical compartments in vivo through the actions of the enzyme DHEAS sulfatase. This enzymatic activity facilitates the conversion of hydrophilic DHEAS to the hydrophobic species DHEA, which can then be further metabolized to other steroid hormones. High levels of DHEAS sulfatase reside in tissues where the biological activity of DHEA or its downstream metabolites regulate cellular function. Therefore, control over the activity of DHEAS sulfatase may represent an important regulatory process for the production of DHEA and its metabolites. Homogeneous populations of macrophages from normal mice were found to effectively convert DHEAS to DHEA in vitro. DHEAS sulfatase activity could be markedly depressed after exposure of these cells to a variety of nonspecific macrophage activators [i.e. zymosan, polyinosine/cytosine, heat-killed bacteria, or bacterial lipopolysaccharide (LPS)]. Inhibition of DHEAS metabolism was found to require protein synthesis, because temporary abrogation of protein synthesis with cycloheximide eliminated the ability of LPS to depress the conversion of DHEAS to DHEA. Additionally, exposure of LPS-nonresponsive macrophages to supernatants derived from LPS-treated BALB/c macrophages inhibited their ability to convert DHEAS to DHEA. Potent inhibition of sulfatase activity could be achieved by directly exposing murine macrophages to interferon-alpha (IFN alpha), IFN beta, or tumor necrosis factor-alpha, but not interleukin-1, interleukin-6, granulocyte-macrophage colony-stimulating factor, transforming growth factor-beta, platelet-derived growth factor, or the T-cell product IFN gamma. Our results indicate that macrophage metabolism of DHEAS to DHEA is down-regulated after cellular activation. Furthermore, inhibition of DHEAS sulfatase activity appears to be mediated through the actions of the inflammatory cytokines tumor necrosis factor-alpha and IFN alpha/beta.
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PMID:Regulation of macrophage dehydroepiandrosterone sulfate metabolism by inflammatory cytokines. 801 93

The aging process is associated with significant declines in the levels of many hormones and trophic factors including estrogen, testosterone, growth hormone (somatropin, somatotropin) and insulin-like growth factor-1 (IGF-1, somatomedin-1, somatomedin-C). Since the classic age-related changes resemble the signs and symptoms of endocrine deficiency, it has been hypothesised that some of the negative effects of aging are due to these hormonal deficits. Consequently, the potential role of hormonal replacement in reversing the deleterious effects of aging deserves investigation. In old hypogonadal men, preliminary studies have shown that testosterone replacement not only improves libido but also significantly increases musculoskeletal mass and strength. However, adverse effects have included increases in haematocrit and prostate specific antigen. Similarly, short term studies with growth hormone replacement have shown substantial bodyweight gain, particularly in severely malnourished older adults, but longer studies have been limited by adverse effects such as gynaecomastia and carpal tunnel syndrome in a few people. Thus, though both testosterone and growth hormone may have potential roles for frailty syndromes in the elderly, long term clinical trials are needed to confirm these positive effects and assess their safety. On the other hand, the multiple beneficial effects of estrogen replacement in older women such as relieving acute menopausal symptoms and preventing postmenopausal osteoporosis are well recognised. Observational studies also suggest that estrogen may decrease cardiovascular disease. However, the optimum duration of treatment and the best way to administer this hormone are still unknown. Also, estrogen may be less effective in senile osteoporosis which primarily results from age-related bone loss. Traditionally, age-related bone loss has been attributed to impaired vitamin D activation and decreased calcium absorption. Thus, it was thought that such bone losses may be ameliorated by calcium supplementation. However, recent studies suggest that alterations in local factors affecting bone cell function may also be important in the pathogenesis of osteoporosis. An increase in potent bone resorbing factors, such as the cytokines interleukin-1 and interleukin-6, has been recently demonstrated in elderly patients with osteoporosis. In these patients, it has been suggested that there may also be a decrease in bone growth factors such as IGF-1 and transforming growth factor-beta. Accordingly, studies are underway to determine whether these factors may be useful in the prevention of osteoporosis. Other growth factors recently identified which may be important in aging include epidermal growth factor, nerve growth factor and fibroblast growth factor.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Trophic factors in aging. Should older people receive hormonal replacement therapy? 807 75

Recent analysis of a various kinds of cytokines revealed that the cytokines are actively involved in a number of important biological functions including immunological and endocrine functions. The present study investigated the unique cytokine-mediated immunological and endocrinological functions in the intra-uterine space during pregnancy. A human placenta which expresses paternal and maternal antigens was revealed to escape from maternal immune systems by releasing immunosuppressive cytokines derived from the placenta. Placental cytokines such as interleukin-6 (IL-6) activated IL-6-receptor-mediated signal transduction pathways to produce human chorionic gonadotropin (hCG). IL-1 and tumor necrosis factor-alpha (TNF-alpha) synergistically augmented IL-6 production to stimulate hCG production. However, transforming growth factor-beta (TGF-beta) suppressed these cytokine-mediated hCG production as well as IL-6 production. Thus, these placental cytokines, mainly derived from trophoblasts, cooperatively contributed to hCG production. IL-8 and monocyte chemotactic and activating factor (MCAF) activate host defense mechanism by activating neutrophils and monocytes as well as macrophages, respectively. IL-6 also activates immune responses and promote synthesis of acute-phase reactant proteins, contributing to augmentation of host defense mechanism in a different way from IL-8 and MCAF. Human placenta in the 3rd trimester actively produced these cytokines for potentiation of placental defense mechanism during pregnancy and in chorioamnionitis. A fetus in chorioamnionitis also produced these cytokines in utero for potentiation of fetal defense mechanism. Among these cytokines, IL-8 in a cord serum was a very sensitive and useful marker for clinical diagnosis of chorioamnionitis. Cord serum IL-6, in contrast, stimulated the synthesis of surfactant protein-A (SP-A) to promote fetal lung maturation and reduce the incidence of RDS. Collectively, the present study revealed the cytokine network in the placenta regulating maternal immune responses, placental endocrine functions, feto-maternal defense mechanism and fetal respiratory maturation.
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PMID:[Immunological analysis of the mechanism of maternal tolerance of a fetus and the cytokine-mediated regulation of feto-placental functions]. 808 6

Tumor necrosis factor-alpha (TNF-alpha), a cytokine produced by astrocytes in vivo and in vitro, was tested for its effects on two malignant astrocytoma cell lines (A-172, U-87). Both lines were immunoreactive for glial fibrillary acidic protein, vimentin, Class I antigens, and interleukin-6. The lines differed in their expression of Class II and intercellular adhesion molecule-1 (ICAM-1) antigenic determinants: A-172 cells were negative for both Class II and ICAM-1 antigens, while U-87 cells were intensely positive for Class II and weakly positive for ICAM-1. When these astrocytoma cell lines were exposed to TNF-alpha, A-172 growth was stimulated while U-87 growth was inhibited. Furthermore, in U-87 cells, TNF-alpha enhanced both ICAM-1 and interleukin-1 beta (IL-1 beta) expression, and decreased immunoreactivity for transforming growth factor-beta (TGF-beta) protein. In contrast, in the presence of TNF-alpha, A-172 cells remained negative for IL-1 beta and TGF-beta, but showed an increased expression of ICAM-1. These results demonstrate that TNF-alpha can induce changes in growth rate, cytokine production, and surface antigen expression in malignant astrocytomas; however, the nature of these changes is dependent on the specific characteristics of these malignant astrocytomas. The resultant variability in the immunological microenvironment of these tumors may reflect differences in their growth potential.
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PMID:Differential effects of tumor necrosis factor-alpha on proliferation, cell surface antigen expression, and cytokine interactions in malignant gliomas. 809 40

A human myeloma cell line, PCM6, was newly established from peripheral blood of a patient with advanced IgG myeloma by addition of recombinant interleukin-6 (IL-6) in culture. PCM6 cells had a morphology typical of mature plasma cells. Cytogenetic and surface marker studies confirmed that PCM6 cells were identical to fresh myeloma cells. Coculture of PCM6 cells with normal bone marrow mononuclear cells resulted in increased colony size of bone marrow-derived fibroblastoid colony-forming cells (CFU-F). Conditioned medium of PCM6 (PCM6-CM) cells increased the CFU-F colony size in a dose-dependent manner. The activity was labile to trypsin treatment but was heat stable (60 degrees C, 30 minutes). Molecular weight of the activity was approximately 165 kd by Sephacryl S-300 gel filtration. Platelet-derived growth factor (PDGF), epidermal growth factor (EGF), transforming growth factor-beta (TGF-beta), and IL-1 beta were not detectable in the conditioned medium. These findings suggest that in some myeloma cases, bone marrow stroma may be affected by CFU-F growth-promoting activity.
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PMID:Establishment of a human myeloma cell line with growth-promoting activity for bone marrow-derived fibroblastoid colony-forming cells. 811 25

Surgical removal of early-stage radial growth phase or vertical growth phase primary cutaneous human melanomas usually results in cure of the disease. Hence there are few examples of genetically-related paired human melanoma cell lines for study in which one member of the pair is from a curable early-stage lesion and the partner is a more aggressive malignant variant. A rapid method of obtaining such variants is described. It consists of injecting cells from established early-stage radial growth phase or vertical growth phase melanoma cell lines--which are normally non- or poorly tumorigenic in nude mice--into such hosts, where the cell inoculum is co-mixed with Matrigel, a reconstituted basement membrane extract. This resulted in the rapid formation of progressively growing solid tumors from which permanent cell lines were established. Subsequently, the sublines were found to be frankly tumorigenic upon retransplantation into new nude mouse hosts in the absence of Matrigel co-injection. This process was repeated a second time, resulting in the isolation of secondary sublines, manifesting a stepwise increase in tumorigenic properties. The tumorigenic variant sublines were examined for their relative sensitivity to a panel of different cytokines that are normally growth inhibitory for melanoma cells from early-stage primary lesions. All the sublines were found to express an increased resistance to the cytokines transforming growth factor-beta, interleukin-6, interleukin-1 and tumor necrosis factor-alpha, and did so in a stable manner. Thus the results support the hypothesis that a progressive multicytokine resistance accompanies the progression of human melanoma. The availability of such related sublines should provide a valuable resource to help study the changes associated with, and perhaps causative of, disease progression in human malignant melanomas.
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PMID:Variant sublines of early-stage human melanomas selected for tumorigenicity in nude mice express a multicytokine-resistant phenotype. 816 Jul 77


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