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)

Interleukin-6 (IL-6) is one of the pathogenetic elements in inflammatory and age-related diseases such as rheumatoid arthritis, osteoporosis, atherosclerosis, and late-onset B cell neoplasia. In these diseases or during aging, the decrease in production of sex hormones such as dehydroepiandrosterone (DHEA) is thought to play an important role in IL-6-mediated pathogenetic effects in mice. In humans, we investigated the correlation of serum levels of DHEA, DHEA sulfate (DHEAS), or androstenedione (ASD) and IL-6, tumor necrosis factor-alpha, or IL-2 with age in 120 female and male healthy subjects (15-75 yr of age). Serum DHEA, DHEAS, and ASD levels significantly decreased with age (all P < 0.001), whereas serum IL-6 levels significantly increased with age (P < 0.001). DHEA/DHEAS and IL-6 (but not tumor necrosis factor-alpha or IL-2) were inversely correlated (all patients: r = -0.242/-0.312; P = 0.010/0.001). In female and male subjects, DHEA and ASD concentration dependently inhibited IL-6 production from peripheral blood mononuclear cells (P = 0.001). The concentration-response curve for DHEA was U shaped (maximal effective concentration, 1-5 x 10(-8) mol/L), which may be the optimal range for immunomodulation. In summary, the data indicate a functional link between DHEA or ASD and IL-6. It is concluded that the increase in IL-6 production during the process of aging might be due to diminished DHEA and ASD secretion. Immunosenescence may be directly related to endocrinosenescence, which, in turn, may be a significant cofactor for the manifestation of inflammatory and age-related diseases.
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PMID:Serum dehydroepiandrosterone (DHEA) and DHEA sulfate are negatively correlated with serum interleukin-6 (IL-6), and DHEA inhibits IL-6 secretion from mononuclear cells in man in vitro: possible link between endocrinosenescence and immunosenescence. 962 33

Estrogen supplements are the primary pharmacologic intervention therapy to prevent and treat loss of bone mass (osteoporosis) in postmenopausal women. Furthermore, at sites of local inflammation near bone, estrogen-deficient women are significantly more susceptible to bone loss than are estrogen-sufficient women. In the present study, we investigate whether estrogen modulates osteoblast (MG-63) production of interleukin-6 (IL-6), an osteoclast recruitment and differentiation of cytokine, in the presence of the proinflammatory cytokine, IL-1beta. Using enzyme-linked immunosorbent assay (ELISA), we demonstrate that IL-1beta significantly enhances IL-6 secretion into culture supernatants in a dose-dependent and time-dependent manner. Using reverse-transcriptase polymerase chain reaction (RT-PCR) and ELISA respectively, we demonstrate further that levels of 17beta-estradiol (active metabolite of estrogen) > or = those found in serum of estrogen-sufficient women inhibit steady-state IL-6 mRNA levels as well as inhibit secretion of IL-6 into culture supernatants. One mechanism by which estrogen therapy preserves bone mass in areas of inflammation may be via inhibition of IL-1beta-stimulated obsteoblast-derived IL-6.
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PMID:Estrogen inhibits interleukin-1beta-induced interleukin-6 production by human osteoblast-like cells. 971 63

Tumor necrosis factor-alpha (TNF-alpha) plays a key role in inflammatory diseases such as rheumatoid arthritis and in postmenopausal osteoporosis. In various tissues, TNF-alpha action is mediated by a transcription factor, nuclear factor-kappa B (NF-kappaB). However, little is known about how TNF-alpha exerts its action in osteoblasts. We thus examined the effect of TNF-alpha on the activation of NF-kappaB in rat osteoblast-like osteosarcoma cells (ROS17/2.8). Electrophoretic mobility shift assay revealed that the activation of the p50-p65 heterodimer NF-kappaB was induced by TNF-alpha as early as 15 minutes followed by a persistent activation for 48 h. When the binding activity of NF-kappaB in cytosol was examined using detergents that dissociate NF-kappaB from an inhibitory protein IkappaB, it decreased during the initial 30 minutes and then increased to the unstimulated level. Northern blot analysis revealed a marked increase in the mRNA levels of p105, a precursor of p50, 6 h after TNF-alpha and a gradual increase in p65 mRNA levels during the initial 1 h. Significant increase in both mRNA levels continued until 24 h after TNF-alpha. These results suggest that the rapid activation of NF-kappaB by TNF-alpha is mainly due to the nuclear translocation of NF-kappaB pre-existing in cytosol, and that the subsequent increase in the expression of p50 and p65 may result in the persistent activation of NF-kappaB during TNF-alpha stimulation. TNF-alpha also increased the mRNA levels of interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1). An antioxidant, N-acetyl-L-cysteine, significantly attenuated the TNF-alpha-dependent increase in these mRNAs, and simultaneously reduced the activation of NF-kappaB by TNF-alpha, indicating that NF-kappaB mediates the TNF-alpha-dependent expression of IL-6 and ICAM-1 in ROS17/2.8 cells. These results suggest that the activation of NF-kappaB by TNF-alpha may play an important role in the production of cytokines and cell adhesion molecules from osteoblasts, leading to the promotion of bone resorption and inflammation.
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PMID:TNF-alpha increases expression of IL-6 and ICAM-1 genes through activation of NF-kappaB in osteoblast-like ROS17/2.8 cells. 971 98

Increased levels of interleukin-6 (IL-6) have been proposed to contribute to a number of pathological disorders, including osteoporosis and Alzheimer's disease. In human atherosclerotic lesions, IL-6 protein and mRNA have been detected, although the role of IL-6 in plaque formation is unknown. We have examined the expression pattern of IL-6 mRNA and secreted protein in male apolipoprotein E-knockout (apoE-KO) mice aortas. Furthermore, we have evaluated the effects of 17beta-estradiol (E2), a vasculoprotective sex steroid hormone, on the secretion of this inflammatory cytokine from isolated male apoE-KO mice aortas. The expression of IL-6 mRNA was detected by reverse transcription-polymerase chain reaction in the apoE-KO mouse aortas but not in the aortas of age-matched control mice. Similarly, the secretion of IL-6 protein from isolated apoE-KO aortic segments was significantly greater than that from aortas of age-matched control animals. The secretion of IL-6 from isolated aortic rings of apoE-KO mice ranging in age from 6 to 48 weeks showed a significant, positive correlation with percent lesion area measured in the same tissue. Immunohistochemical staining of apoE-KO mouse aortic tissue sections demonstrated colocalization of IL-6 expression with macrophages. Treatment of male apoE-KO mice with E2 for 3 weeks resulted in a statistically significant 50% reduction in IL-6 secretion from ex vivo aortic tissue segments. There was no significant change in total serum cholesterol and triglyceride levels in the E2-treated group compared with placebo-treated controls. These data demonstrate that (1) IL-6 mRNA and protein are expressed in the atherosclerotic plaques of apoE-KO mice aortas and (2) IL-6 production is suppressed by E2 treatment, which may contribute to the antiatherosclerotic effects of E2 in the apoE-KO mouse model of atherosclerosis.
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PMID:Expression of interleukin-6 in atherosclerotic lesions of male ApoE-knockout mice: inhibition by 17beta-estradiol. 974 40

Cytokines that stimulate bone resorption are produced by cells found in bone marrow. However, marrow cells produce multiple factors, some of which may be inhibitors of osteoclast differentiation or activity. Thus, it is not possible to predict a priori whether the mixture of factors produced by marrow cells will have a net stimulatory or inhibitory effect on bone resorption. In this study, we showed that the net effect of whole marrow is to inhibit osteoclast activity induced by parathyroid hormone. Fractionation of the marrow revealed that the inhibitory activity was in the marrow fluid. However, conditioned media obtained from marrow cell cultures also inhibited osteoclast activity. Thus, it is likely that the inhibitory factors are produced in vivo by cells residing in the marrow. These inhibitory factors may represent a physiological regulatory process that plays an important role in maintaining the balance between bone resorption and formation. Because we have previously shown that interleukin-6 is one of the cytokines that parathyroid hormone induces in osteoblastic cells to stimulate osteoclast activity, one potential mechanism by which the marrow-derived inhibitory factors might act is by preventing this production of interleukin-6. However, we found that the marrow cell-conditioned media do not inhibit the production or activity of interleukin-6. Thus, the inhibitory factors appear to block osteoclast activity through a mechanism that does not involve interleukin-6. Taken together, these results demonstrate the importance of factors that inhibit bone resorption and emphasize that the presence of cytokines that stimulate bone resorption in conditions such as osteoporosis and orthopaedic implant loosening should be interpreted with caution unless evidence exists demonstrating their functional importance.
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PMID:Bone marrow cells produce soluble factors that inhibit osteoclast activity. 1007 47

A series of 4-phenylthiazole derivatives were synthesized and tested their inhibitory effect on the interleukin-6 secretion stimulated by PTH in osteoblastic cells. SCRC2941-18, 2-amino-4-(4-chlorophenyl)-5-methylthiazole, was found to be the most potent inhibitor in the derivatives. Furthermore, SCRC2941-18 significantly suppressed the bone weight loss in the ovariectomized mice, an osteoporosis model.
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PMID:4-Phenylthiazole derivatives inhibit IL-6 secretion in osteoblastic cells and suppress bone weight loss in ovariectomized mice. 1023 Jun 19

Sex steroids are important regulators of bone cell function and osteoblast-derived matrix metalloproteinases (MMPs) are key mediators of bone resorption during the initial stage of osteoid removal prior to osteoclast attachment. To investigate the mechanism of bone loss following estrogen deficiency, we examined the effects of estrogen on osteoblast synthesis of MMPs and tissue inhibitor of metalloproteinases (TIMPs). Immunolocalization in mouse bone samples ex vivo and primary mouse osteoblast (MOB) cultures was used to document the synthesis of mouse interstitial collagenase (MMP-13), stromelysin-1 (MMP-3), gelatinase-A (MMP-2), and gelatinase-B (MMP-9). Endosteal bone lining cells from distal femoral head and lumbar vertebral body showed an increase in the pattern of synthesis of stromelysin-1 following ovariectomy, compared with sham-operated controls; the synthesis of other MMPs was unaffected. The expression of all classes of MMPs and TIMP-1 and TIMP-2 by MOB in culture was demonstrated by reverse transcriptase-polymerase chain reaction. Following the withdrawal of 17beta-estradiol, MOB cultures showed a significant increase in the number of cells synthesizing stromelysin-1; this effect was enhanced by stimulation with either interleukin-1 or interleukin-6. Northern blot analysis showed only a slight increase in stromelysin-1 mRNA message following the withdrawal of 17beta-estradiol. Our data show an unexpected up-regulation of stromelysin-1 synthesis by osteoblasts both in vivo and in vitro following estrogen withdrawal. Although this effect was not reflected in a significant change in stromelysin-1 mRNA expression in vitro, there is evidence to suggest a role for this enzyme in the early stages of bone loss during the pathogenesis of osteoporosis.
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PMID:Stromelysin (MMP-3) synthesis is up-regulated in estrogen-deficient mouse osteoblasts in vivo and in vitro. 1057 88

We have investigated the role of 23 candidate genes in the control of bone mineral density (BMD) by linkage studies in families of probands with osteoporosis (lumbar spine [LS] or femoral neck [FN] BMD T score < -2.5) and low BMD relative to an age- and gender-matched cohort (Z score < -2.0). One hundred and fifteen probands (35 male, 80 female) and 499 of their first- or second-degree relatives (223 males and 276 females) were recruited for the study. BMD was measured at the LS and FN using dual-energy X-ray absorptiometry and expressed as age- and gender-matched Z scores corrected for body mass index. The candidate genes studied were the androgen receptor, type I collagen A1 (COLIA1), COLIA2, COLIIA1, vitamin D receptor (VDR), colony-stimulating factor 1, calcium-sensing receptor, epidermal growth factor (EGF), estrogen receptor 1 (ESR1), fibrillin type 1, insulin-like growth factor 1, interleukin-1 alpha (IL-1alpha), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-11 (IL-11), osteopontin, parathyroid hormone (PTH), PTH-related peptide, PTH receptor type 1 (PTHR1), transforming growth factor-beta 1, and tumor necrosis factors alpha and beta. Sixty-four microsatellites lying close to or within these genes were investigated for linkage with BMD. Using the program MapMaker/Sibs there was suggestive evidence of linkage between BMD and PTHR1 (maximum LOD score obtained [MLS] 2.7-3.5). Moderate evidence of linkage was also observed with EGF (MLS 1.8), COLIA1 (MLS 1.7), COLIIA1/VDR (MLS 1.7), ESR1 (MLS 1.4), IL-1alpha (MLS 1.4), IL-4 (MLS 1.2), and IL-6 (MLS 1.2). Variance components analysis using the program ACT, correcting for proband-wise ascertainment, also showed evidence of linkage (p </= 0.05) at markers close to or within the candidate genes IL-1alpha, PTHR1, IL-6, and COLIIA1/VDR. Further studies will be required to confirm these findings, to refine the location of gene responsible for the observed linkage, and to screen the candidate genes targeted at these loci for mutations.
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PMID:Suggestive linkage of the parathyroid receptor type 1 to osteoporosis. 1062 57

Postmenopausal women are at increased risk to develop osteoporosis, coronary artery disease, heart failure, and hypertension. Interleukin-6 (IL-6) may be a pathogenetic element in these disorders. Serum IL-6 levels increase during aging and seem to be related to increased body fat mass. In the present retrospective study we aimed to investigate the role of hormone replacement therapy (HRT) on serum IL-6 levels and the interrelation of IL-6 and body fat mass. Parameters were assessed in a population-based sample of postmenopausal women (n = 302) and, for comparison, 245 men of the same age. Women with HRT (n = 92) had significantly lower serum IL-6 levels compared to subjects without HRT, which was independent of age, antihypertensive therapy, smoking habits, and blood pressure (1.5 +/- 0.1 vs. 2.9 +/- 0.6 pg/mL; P = 0.017). In women without HRT, the body mass index (BMI) was correlated with serum IL-6 levels (P < 0.001). Multivariate analysis controlling simultaneously for the effects of blood pressure and heart rate confirmed the positive correlation (P = 0.001). However, in subjects with HRT no such correlation between IL-6 and BMI was demonstrated, which was confirmed after controlling covariates. In male subjects, BMI correlated with serum IL-6 (P = 0.009), which was, however, blunted after controlling for blood pressure and heart rate, probably indicating an influence of the sympathetic nervous system on this interrelation. In conclusion, women receiving HRT display lower serum IL-6 levels and a blunted interrelation of IL-6 and BMI. As IL-6 may be a pathogenetic factor in age-related diseases, HRT-related inhibition of IL-6 secretion could be an important element for the favorable effects of HRT in postmenopausal women.
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PMID:Hormone replacement therapy and interrelation between serum interleukin-6 and body mass index in postmenopausal women: a population-based study. 1072 86

Interleukin-6 (IL-6) is a proinflammatory cytokine that is normally tightly regulated and expressed at low levels, except during infection, trauma, or other stress. Among several factors that down-regulate IL-6 gene expression are estrogen and testosterone. After menopause or andropause, IL-6 levels are elevated, even in the absence of infection, trauma, or stress. IL-6 is a potent mediator of inflammatory processes, and it has been proposed that the age-associated increase in IL-6 accounts for certain of the phenotypic changes of advanced age, particularly those that resemble chronic inflammatory disease [decreased lean body mass, osteopenia, low-grade anemia, decreased serum albumin and cholesterol, and increased inflammatory proteins such as C-reactive protein (CRP) and serum amyloid A]. Furthermore, the age-associated rise in IL-6 has been linked to lymphoproliferative disorders, multiple myeloma, osteoporosis, and Alzheimer's disease. This overview discusses the data relating IL-6 to age-associated diseases and to frailty. Like the syndrome of inappropriate antidiuretic hormone, it is possible that certain clinically important late-life changes are due to an inappropriate presence of IL-6.
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PMID:Age-associated increased interleukin-6 gene expression, late-life diseases, and frailty. 1077 63


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