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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The purpose of this study was to examine the source of adipokines released by the visceral and sc adipose tissues of obese humans. Human adipose tissue incubated in primary culture for 48 h released more prostaglandin E(2),
IL-8
, and IL-6 than adiponectin, whereas the release of plasminogen activator inhibitor 1 and hepatocyte growth factor was less than that of adiponectin but greater than that of
leptin
. IL-10 and TNFalpha were released in amounts less than those of
leptin
, whereas vascular endothelial growth factor and IL1-beta were released in much lower amounts. The accumulation of adipokines was also examined in the three fractions (adipose tissue matrix, isolated stromovascular cells, and adipocytes) obtained by collagenase digestion of adipose tissue. Over 90% of the adipokine release by adipose tissue, except for adiponectin and
leptin
, could be attributed to nonfat cells. Visceral adipose tissue released greater amounts of vascular endothelial growth factor, IL-6, and plasminogen activator inhibitor 1 compared with abdominal sc tissue. The greatly enhanced total release of TNFalpha,
IL-8
, and IL-10 by adipose tissue from individuals with a body mass index of 45 compared with 32 was due to nonfat cells. Furthermore, most of the adipokine release by the nonfat cells of adipose tissue was due to cells retained in the tissue matrix after collagenase digestion.
...
PMID:Comparison of the release of adipokines by adipose tissue, adipose tissue matrix, and adipocytes from visceral and subcutaneous abdominal adipose tissues of obese humans. 1472 44
Numerous signals convey information about body fat status from the periphery to the brain areas that control energy homeostasis so that, throughout life, body weight remains nearly stable. These signals mainly originate, either from the adipose tissue, like
leptin
and to a lesser extent interleukin 6, or from the pancreas, like insulin and amylin. These factors circulate in proportion to body fat mass and they are referred to as "adiposity signals". It is well established, at least for
leptin
and insulin, that they enter the brain from the plasma where they induce/repress a network of important neuropeptide regulators of energy intake and expenditure. Beside these endocrine signals, a growing amount of literature show data relative to adipocyte-derived molecules, most of them belonging to the cytokine family, like IL6, TNFalpha,
IL8
, IL10 whose secretion also correlates with body fat mass and that may locally regulate fat mass expansion. Others, like adiponectin, are negatively correlated with body fat mass. These "adiposity molecules" have already been involved in insulin resistance associated with obesity and inflammatory process. They may participate to a complex inter organ dialogue. In this review, we will synthesize data relative to the role played by insulin,
leptin
and amylin, either alone or through a cross talk, in "energy level sensing" at the brain level. Furthermore, we will develop how "adiposity molecules" through their paracrin and/or autocrin action may contribute to maintain fat mass expansion, therefore representing new adiposity molecules per se. Lastly, since any distortion in the metabolic circuitry of energy homeostasis is susceptible to lead to a pathological status like obesity, the impact of known genetic polymorphisms in genes encoding the adiposity signals will be discussed.
...
PMID:Adiposity signals, genetic and body weight regulation in humans. 1522 73
White adipose tissue is now recognised to be a multifunctional organ; in addition to the central role of lipid storage, it has a major endocrine function secreting several hormones, notably
leptin
and adiponectin, and a diverse range of other protein factors. These various protein signals have been given the collective name 'adipocytokines' or 'adipokines'. However, since most are neither 'cytokines' nor 'cytokine-like', it is recommended that the term 'adipokine' be universally adopted to describe a protein that is secreted from (and synthesised by) adipocytes. It is suggested that the term is restricted to proteins secreted from adipocytes, excluding signals released only by the other cell types (such as macrophages) in adipose tissue. The adipokinome (which together with lipid moieties released, such as fatty acids and prostaglandins, constitute the secretome of fat cells) includes proteins involved in lipid metabolism, insulin sensitivity, the alternative complement system, vascular haemostasis, blood pressure regulation and angiogenesis, as well as the regulation of energy balance. In addition, there is a growing list of adipokines involved in inflammation (TNFalpha, IL-1beta, IL-6,
IL-8
, IL-10, transforming growth factor-beta, nerve growth factor) and the acute-phase response (plasminogen activator inhibitor-1, haptoglobin, serum amyloid A). Production of these proteins by adipose tissue is increased in obesity, and raised circulating levels of several acute-phase proteins and inflammatory cytokines has led to the view that the obese are characterised by a state of chronic low-grade inflammation, and that this links causally to insulin resistance and the metabolic syndrome. It is, however, unclear as to the extent to which adipose tissue contributes quantitatively to the elevated circulating levels of these factors in obesity and whether there is a generalised or local state of inflammation. The parsimonious view is that the increased production of inflammatory cytokines and acute-phase proteins by adipose tissue in obesity relates primarily to localised events within the expanding fat depots. It is suggested that these events reflect hypoxia in parts of the growing adipose tissue mass in advance of angiogenesis, and involve the key controller of the cellular response to hypoxia, the transcription factor hypoxia inducible factor-1.
...
PMID:Adipokines: inflammation and the pleiotropic role of white adipose tissue. 1546 38
There is much evidence to indicate a role for adipocytokines in insulin resistance and/or type 2 diabetes mellitus. In experimental models, oral salicylates, through their ability to interfere with the nuclear factor-kappa B (NF-kappa B) transcription pathway, have been demonstrated to reverse insulin resistance. The aim of this study was to investigate whether NF-kappa B regulates the release of adipocytokines in human adipose tissue and skeletal muscle. Human sc adipose tissue and skeletal muscle (obtained from normal pregnant women) were incubated in the absence (control) or presence of two NF-kappa B inhibitors sulfasalazine (1.25, 2.5, and 5 mm) and BAY 11-7082 (25, 50, and 100 microm). After an 18-h incubation, the tissues were collected, and NF-kappa B p65 DNA-binding activity and I kappa B kinase (IKK-beta) and insulin receptor-beta protein expression were assessed by ELISA and Western blotting, respectively. The incubation medium was collected, and the release of TNF-alpha, IL-6,
IL-8
, resistin, adiponectin, and
leptin
was quantified by ELISA. Treatment of adipose tissue and skeletal muscle with sulfasalazine and BAY 11-7082 significantly inhibited the release of IL-6,
IL-8
, and TNF-alpha; NF-kappa B p65 DNA-binding activity; and IKK-beta protein expression (P < 0.05, by Newman-Keuls test). There was no effect of sulfasalazine and BAY 11-7082 on resistin, adiponectin, or
leptin
release. Both sulfasalazine and BAY 11-7082 increased the adipose tissue and skeletal muscle expression of insulin receptor-beta. The data presented in this study demonstrate that the IKK-beta/NF-kappa B transcription pathway is a key regulator of IL-6,
IL-8
, and TNF-alpha release from adipose tissue and skeletal muscle. Control of the IKK-beta/NF-kappa B pathway may therefore provide an alternative therapeutic strategy for regulating aberrant cytokine release and thereby alleviating insulin resistance in type 2 diabetes mellitus.
...
PMID:Sulfasalazine and BAY 11-7082 interfere with the nuclear factor-kappa B and I kappa B kinase pathway to regulate the release of proinflammatory cytokines from human adipose tissue and skeletal muscle in vitro. 1556 33
The objective of the present report was to clarify the postoperative stress response of some inflammatory markers, namely of proinflammatory cytokines and
leptin
levels during uncomplicated postoperative periods. The results were compared with the dynamics of these parameters during intraabdominal sepsis. We followed 20 patients after a planned resection of colorectal cancer in stage Ib-IV with uncomplicated healing and 13 obese men after laparoscopic non-adjustable gastric banding. These were compared to 12 patients with proven postoperative sepsis. The control group consisted of 18 healthy men. The observed parameters included serum levels of cytokines, tumor necrosis factor-alpha (TNFalpha), interleukin-1 beta (IL-1 beta), interleukin-1 receptor antagonist (IL-1 ra), IL-6,
IL-8
, soluble receptor of interleukin-2 (sIL-2R) and
leptin
. It was found that during the first 24 h after resection there was a significant increase in the serum concentration of IL-6 up to 1125+/-240 ng/l, which declined within the next 48-72 h. Serum concentration of TNFalpha was highest 18-24 h after resection (205+/-22 ng/l) and after banding (184+/-77 ng/l). IL-1 beta had a stable serum concentration without significant elevation. Serum concentration of
IL-8
after resection rose to 520+/-200 ng/l after 36-48 h. Maximal cytokine levels after gastric banding were quantitatively lower (IL-6 414+/-240 ng/l, TNFalpha 184+/-77 ng/l) than after resection. We found significant elevation of plasma
leptin
concentration (32+/-10 ng/ml) 24 h after banding compared with preoperative values (18+/-5 ng/ml, p 0.05). Leptin levels 48 and 72 h after banding rapidly returned to the level before operation. During abdominal surgery
leptin
shows to be an acute phase reactant. Proinflammatory cytokines can be main regulatory factors of
leptin
during this period. Significant correlation between
leptin
and TNFalpha (similarly demonstrated by other authors in models of bacterial inflammation) indicates that TNFalpha can be the crucial regulator of
leptin
generation in the early postoperative period. On the basis of our results we recommend to observe IL-6 and
IL-8
at 24-72 h after the surgery in patients with a high risk of early postoperative septic complications.
...
PMID:The postoperative stress response and its reflection in cytokine network and leptin plasma levels. 1558 61
The present studies were designed to investigate the hormonal regulation of vascular endothelial growth factor (VEGF) release by human subcutaneous adipose tissue explants and adipocytes incubated in primary culture for 48 hours. Vascular endothelial growth factor and
IL-8
release by adipocytes were less than 10% of that by tissue explants, whereas that of
leptin
in adipocytes was comparable to that by tissue. Dexamethasone inhibited VEGF formation by both adipose tissue explants and isolated adipocytes, whereas insulin stimulated VEGF release only in isolated adipocytes. Insulin also enhanced the formation of
IL-8
and plasminogen activation inhibitor 1 (PAI-1), but not that of IL-6 by adipocytes although having little effect on that of IL-6 or PAI-1 by adipose tissue explants. Pertussis toxin stimulated lipolysis and inhibited
leptin
release by human adipose tissue or adipocytes but did not affect release of
IL-8
or VEGF. Isoproterenol also stimulated lipolysis by human adipocytes, but this was not accompanied by any significant changes in VEGF,
IL-8
, IL-6, or PAI-1 release. In contrast, insulin stimulated VEGF release by human adipocytes, and this stimulation was enhanced in the presence of isoproterenol. Insulin stimulated VEGF formation as well as that of PAI-1 by human adipocytes, but not by explants under conditions where it had little effect on that of IL-6. The ability of insulin to stimulate VEGF formation by adipocytes suggests that the elevated circulating levels of insulin in obesity promote angiogenesis in adipose tissue as well as the enhanced accumulation of fat in human adipocytes.
...
PMID:Insulin enhances vascular endothelial growth factor, interleukin-8, and plasminogen activator inhibitor 1 but not interleukin-6 release by human adipocytes. 1569 Mar 17
Although homocysteine (Hcy) inhibits angiogenesis in vivo and in vitro, the mechanism(s) underlying this phenomenon are largely unclear. The hypothesis of the present work is that Hcy, while inducing the expression of antiangiogenic factors, inhibits the production of angiogenic factors. Mouse brain microvascular endothelial cells (MVEC) were cultured in the presence and absence of 20 microM Hcy for 24 hr in serum-free medium. Cell homogenates were incubated with Trans-Signal Angiogenesis Antibody Array containing antibodies to angiogenic activators (ANG, HGF,
leptin
, VEGF, IL-6,
IL-8
, PIGF, FGF-alpha/beta, TNF-alpha and TGF-alpha) and inhibitors (IFN-gamma, IL-12, IP-10, TIMP-1 and -2). The array membranes were scanned and normalized with positive controls. Angiogenesis and formation of capillaries were measured by culturing the MVEC in Matrigels. The capillary-like structures were identified by transmission microscopy. Hcy decreased the expression of
leptin
, IL-6, -8, PIGF, FGF-alpha and VEGF, while the levels of anti-angiogenic IL-12, IP-10 (chemokine) and TIMP-1 were increased by Hcy. The vascular tube-like structures by MVEC were decreased by increased Hcy. However, the addition of VEGF to Hcy-treated MVEC ameliorated the decreased Hcy-mediated capillary formation. The results suggest that Hcy inhibits angiogenesis, in part, by decreasing VEGF and increasing TIMP-1.
...
PMID:Proteomic analysis of homocysteine inhibition of microvascular endothelial cell angiogenesis. 1570 57
The aim of this study was to investigate the changes in serum levels of
leptin
, cytokines and lipoproteins in women with pre-eclampsia and to evaluate their clinical significance in the pathogenesis of pre-eclampsia. We performed a prospective study involving 45 women with pre-eclampsia in the third trimester of pregnancy and 30 normotensive women in the third trimester of pregnancy. Serum level of
leptin
was measured by enzyme immunoassay using a Cayman chemical kit. Serum levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, soluble IL-2 receptor (slL-2R), IL-6 and
IL-8
were measured by using a non-radioimmunoassay chemiluminescent method. Serum lipid concentrations were measured by an Abbott Aeroset (USA) autoanalyzer. Serum levels of apolipoprotein (Apo)A-I and ApoB were evaluated by nephelometrics assays. Differences between groups were evaluated with Student's unpaired t test and, when a variable was not normally distributed, the Mann-Whitney U test was used. The relationship between the variable was explored by the Pearson correlation test. Serum levels of
leptin
, TNF-alpha, IL-1beta, sIL-2R, IL-6 and
IL-8
in the pre-eclamptic women were significantly higher than in normotensive women (p < 0.001). In the pre-eclamptic women serum levels of triglycerides, total cholesterol and low-density lipoprotein (LDL)-cholesterol were significantly increased (p < 0.001), while high-density lipoprotein (HDL)-cholesterol and Apo-A were significantly decreased compared to levels in normotensive pregnant women (p < 0.001). No significant differences were noted between the groups in Apo-B (p > 0.05). Serum levels of TNF-alpha were significantly correlated with the serum levels of IL-6,
IL-8
, triglycerides, sIL-2R, Apo-A and hematocrit in pre-eclamptic women (r = 0.418, p < 0.05; r= 0.389, p < 0.01; r=0.312, p < 0.05; r= -0.318, p < 0.05; r= -0.340, p < 0.05 and r=0.41, p < 0.01, respectively). A negative correlation was seen between serum level of
leptin
and both IL-1beta and Apo-A in pre-eclamptic women (r=-0.44, p < 0.05; r=-0.39, p < 0.05, respectively). Serum levels of IL-6 were also significantly correlated with the serum levels of HDL-cholesterol, LDL-cholesterol and body mass index (BMI) in pre-eclamptic women (r=0.40, p < 0.01; r=-0.568, p < 0.01; r= -0.30, p < 0.05, respectively). In addition, serum level of
IL-8
were significantly correlated with the serum levels of HDL-cholesterol, total cholesterol and BMI in pre-eclamptic women (r= 0.368, p < 0.05; r=0.513, p < 0.01 and r= -0.41, p < 0.01, respectively). We found that the pre-eclampsia associated with increases in serum levels of
leptin
, TNF-alpha, cytokines, triglycerides, total cholesterol and LDL-cholesterol was associated with a significant reduction in serum levels of HDL-cholesterol and Apo-A. These association may be due to the abnormal lipid metabolism and immune activation involved in the pathogenesis of this disease.
...
PMID:Changes in serum levels of leptin, cytokines and lipoprotein in pre-eclamptic and normotensive pregnant women. 1572 15
Explants of human adipose tissue from nonobese subjects were cultured for 24 h with or without the presence of 20 ng/ml TNFalpha. Gene expression and/or medium concentrations of interleukin (IL)-1beta, IL-1 receptor antagonist (IL-1 RA), TNFalpha, IL-6,
IL-8
, resistin, PAI-1 and
leptin
were analysed. TNFalpha increased the mRNA levels of TNFalpha itself as well as IL-6,
IL-8
, IL-1beta and PAI-1, but not
leptin
. The medium concentrations of IL-1 RA, IL-6 and
IL-8
were markedly increased by TNFalpha while no measurable release of TNFalpha, resistin or IL-1beta to the medium was found. Thus, human adipose tissue from nonobese individuals releases substantial amounts of IL-6,
IL-8
and IL-1 RA and the gene expression of these cytokines, like that of IL-1beta and PAI-1, is regulated by TNFalpha. However, since neither TNFalpha, resistin or IL-1beta was found in the culture medium, such a regulatory effect by TNFalpha on adipose tissue in vivo is likely to be mediated through a paracrine mechanism where invaded inflammatory cells may play a critical role.
...
PMID:Cytokine release from adipose tissue of nonobese individuals. 1591 41
Adipose tissue has been recognised as the quantitatively most important energy store of the human body for many years, in addition to its functions as mechanical and thermic insulator. In mammals, the adipose organ is localised in several depots including white as well as brown adipose tissues. The largest depots are found subcutaneously and in the abdominal region. Several secretory proteins are synthesised in adipose tissue including
leptin
, resistin, adiponectin, tumor necrosis factor (TNFalpha), angiotensinogen, adipsin, acylation-stimulating protein, retinol-binding protein (RBP), interleukin (IL)-1b, IL-6,
IL-8
, IL-10, plasminogen activator inhibitor-1 (PAI-1), fasting-induced adipose factor, fibrinogen-angiopoietin-related protein, metallothionein, tissue factor (TF), complement C3, fibronectin, haptoglobin, entactin/nidogen, collagen VI alpha 3, pigment epithelium-derived factor (PEDF), hippocampal cholinergic neurostimulating peptide (HCNP), neutrophil gelatinase-associated lipocalin (NGAL) and adiponutrin. Fatty acids may influence the expression of adipokines like
leptin
, resistin or adiponectin directly by interaction with transcription factors, or indirectly via unknown mechanisms possibly linked to fatty acid oxidation, synthesis or storage. Because fatty acids are the main components of adipose tissue, it is of essential interest to clarify the biological effects of different types of fatty acids on the expression of relevant adipokines.
...
PMID:Fatty acids and expression of adipokines. 1594 95
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