首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Dysregulation of cytokines synthesis is thought to play a role in the development of a number of age-related conditions, such as rheumatoid arthritis, osteoporosis, atherosclerosis, and others, but observational studies have led to contradictory results. We investigated potential familial influences on the plasma levels of IL-6 and TNF-alpha in 91 nuclear and more complex pedigrees of Caucasian ethnic origin (N=401 individuals). The maximum likelihood based variance decomposition analysis showed significant positive correlation between circulating IL-6 and age in both genders. The magnitude of these correlations in our sample ranged from 0.22 in females to 0.28 in males (P<0.001). Significant association between TNF-alpha and IL-6 (r=0.28, r=0.43; P<0.001; respectively for men and women) was also observed. Likelihood ratio test clearly revealed that additive genetic effect for TNF-alpha was highly significant (P<0.001), and accounted over 80% of its variation, adjusted for IL-6 levels and age. In contrast, heritability estimate for IL-6 adjusted for age and TNF-alpha, revealed small contribution of genetic factors (24.1 +/- 10.2%). The bivariate variance component analysis demonstrated that significant relationship between IL-6 and TNF-alpha was due to shared environment only (r(E)=0.760 +/- 0.140). As evinced from our complex segregation analysis the nature of the genetic determinant of each of these two cytokines is quite complex and it is probably oligogenic.  相似文献   

3.
Human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is a side effect of highly active antiretroviral therapy of HIV-infected patients; however, the mechanism of the lipodystrophy and insulin resistance seen in this syndrome remains elusive. Adiponectin, an adipocyte-specific protein, is thought to play an important role in regulating insulin sensitivity. We investigated circulating levels and gene expression of adiponectin in subcutaneous abdominal adipose tissue (AT) from 18 HIV-infected patients with HALS compared with 18 HIV-infected patients without HALS. Implications of cytokines for adiponectin levels were investigated by determining circulating levels of TNF-alpha, IL-6, and IL-8 as well as gene expression of these cytokines in AT. HALS patients exhibited 40% reduced plasma adiponectin levels (P < 0.05) compared with non-HALS subjects. Correspondingly, adiponectin mRNA levels in AT were reduced by >50% (P = 0.06). HALS patients were insulin resistant, and a positive correlation was found between plasma adiponectin and insulin sensitivity (r = 0.55, P < 0.01) and percent limb fat (r = 0.61, P < 0.01). AT mRNA of TNF-alpha, IL-6, and IL-8 was increased in AT of HALS subjects (P < 0.05), and both AT TNF-alpha mRNA and plasma TNF-alpha were negatively correlated to plasma adiponectin (P < 0.05). Finally, TNF-alpha was found in vitro to inhibit human AT adiponectin mRNA by 80% (P < 0.05). In conclusion, HALS patients have reduced levels of plasma adiponectin and adiponectin mRNA in AT. Increased cytokine mRNA in AT is hypothesized to exert an inhibitory effect on adiponectin gene expression and, consequently, to play a role in the reduced plasma adiponectin levels found in HALS patients.  相似文献   

4.
5.
Newborns are at increased risk of overwhelming infection, yet the mechanisms underlying this susceptibility are incompletely defined. In this study we report a striking 1- to 3-log decrease in sensitivity of monocytes in human neonatal cord blood, compared with monocytes in adult peripheral blood, to the TNF-alpha-inducing effect of multiple TLR ligands, including bacterial lipopeptides (BLPs), LPS, and the imidazoquinoline compound, imiquimod. In marked contrast, TNF-alpha release in response to R-848, a TLR ligand that is a congener of imiquimod, was equivalent in newborn and adult blood. Differences in ligand-induced TNF-alpha release correlated with divergent ligand-induced changes in monocyte TNF-alpha mRNA levels. Newborn and adult monocytes did not differ in basal mRNA or protein expression of TLRs or mRNA expression of functionally related molecules. Newborn monocytes demonstrated diminished LPS-induced, but equivalent R-848-induced, phosphorylation of p38 mitogen-activated protein kinase and altered BLP- and LPS-induced acute modulation of cognate receptors, suggesting that the mechanism accounting for the observed differences may be localized proximal to ligand recognition by surface TLRs. Remarkably, newborn plasma conferred substantially reduced BLP-, LPS-, and imiquimod-induced TNF-alpha release on adult monocytes without any effect on R-848-induced TNF-alpha release, reflecting differences in a plasma factor(s) distinct from soluble CD14. Impaired response to multiple TLR ligands may significantly contribute to immature neonatal immunity. Conversely, relative preservation of responses to R-848 may present unique opportunities for augmenting innate and acquired immunity in the human newborn.  相似文献   

6.
Dysregulated inflammation is a complication of type 2 diabetes (T2D). In this study, we show that augmented LPS-induced TNF-alpha production by resident peritoneal macrophages (PerMphi) in type 2 diabetic (db/db) mice is dependent on elevated glucose and requires p38 MAPK. Intraperitoneal LPS administered to db/db and nondiabetic (db/+) mice induced 3- and 4-fold more TNF-alpha in the peritoneum and serum, respectively, of db/db mice as compared with db/+ mice. Examination of the TLR-4/MD2 complex and CD14 expression showed no difference between db/db and db/+ PerMphi. Ex vivo stimulation of PerMphi with LPS produced a similar 3-fold increase in TNF-alpha production in db/db PerMphi when compared with db/+ PerMphi. PerMphi isolated from db/+ mice incubated in high glucose (4 g/L) medium for 12 h produced nearly 2-fold more TNF-alpha in response to LPS than PerMphi incubated in normal glucose medium (1 g/L). LPS-dependent stimulation of PI3K activity, ERK1/2 activation, and p38 kinase activity was greater in PerMphi from db/db mice as compared with db/+ mice. Only inhibition of p38 kinase blocked LPS-induced TNF-alpha production in PerMphi from db/db mice. Taken together, these data indicate that augmented TNF-alpha production induced by LPS in macrophages during diabetes is due to hyperglycemia and increased LPS-dependent activation of p38 kinase.  相似文献   

7.
INTRODUCTION: Recent clinical and experimental studies indicate that upregulation of the TNF system can contribute to the progression of cardiac remodeling and heart failure decompensation, by promoting alterations in cardiomyocyte biology and extracellular matrix metabolism. Extracellular matrix turnover is regulated by the matrix metalloproteinases (MMPs), which are endogenous enzymes responsible for extracellular collagen degradation. The present study investigates the fluctuation of serum levels of TNF-alpha, soluble TNF receptor-1 (sTNFR1) and -2 (sTNFR2), in patients with chronic heart failure both during acute decompensation and the stable state of the syndrome. The second goal of this study was to determine if a relationship exists between serum MMPs profiles (MMP-1, MMP-2, MMP-3) and circulating TNF-alpha or its soluble receptors. METHODS: Our patient group consisted of 52 patients with chronic heart failure (NYHA III-IV; mean age: 65 +/- 4 years; hypertensive cardiomyopathy: 20, ischemic cardiomyopathy: 17, dilated cardiomyopathy: 10, valvular disease: 5), who were hospitalized for acute decompensation of the syndrome. Our control group consisted of 30 healthy subjects (mean age: 57 +/- 6 years). Serum levels of TNF-alpha, sTNFR1, sTNFR2 and MMP-1,-2,-3 were measured in heart failure patients by ELISA at admission and after one month as follow-up. Values are expressed as medians and interquartile ranges. RESULTS: In our patient group, we observed a statistically significant increase in the levels of sTNFR1 and sTNFR2 at admission (sTNFR1: 5.15 ng\mL, 4.49-8.90 ng\mL, P < 0.001, sTNFR2: 13.40 ng\mL, 6.10-21.50 ng\mL, P < 0.001), and at one-month follow-up (sTNFR1: 5.30 ng\mL, 4.61-6.90 ng\mL, P < 0.001, sTNFR2: 21.80 ng\mL, 11.50-25.20 ng\mL, P < 0.001), compared to the control group (sTNFR1: 3.83 ng\mL, 3.70-3.95 ng\mL, sTNFR2: 4.00 ng\mL, 3.40-5.40 ng\mL). There was a statistically significant difference in the levels of sTNFR2 between admission and follow-up (P < 0.05). Significant correlations between serum MMP-3 and sTNFR2 levels both at admission and follow up (r -/+ 0.460, P -/+ 0.005 and r -/+ 0.338, P -/+ 0.044, respectively) were also found. CONCLUSIONS: Soluble TNF receptors are elevated in heart failure patients both in acute decompensation and stable phase. We have detected higher levels of soluble TNFR2 during the compensated phase of heart failure, suggesting that TNFR2 receptors appear to stabilize the cytokine and thereby prolong its half-life and biological functions. Finally, TNF system-mediated cardiac remodeling may exist through the activation of MMP-3 signaling pathways.  相似文献   

8.
Tumor necrosis factor-alpha (TNF-alpha) is increasingly recognized as a key component in the development of insulin resistance and increased blood pressure. In a sample of 368 individuals, the ratio of soluble TNF-alpha receptors (sTNFR2/sTNFR1) correlated positively with systolic and diastolic blood pressure (P < 0.01). This ratio was significantly greater in type 2 diabetic subjects (DM-2) than in type 1 diabetic patients and was greater than in control nondiabetic subjects (P < 0.00001). The TNF-alpha receptor 1 (TNFR1) density in peripheral blood monocytes was similar in DM-2 patients and in nondiabetic subjects. After phorbol 12-myristate 13-acetate, TNFR1 shedding was significantly decreased in DM-2 compared with control subjects, and it was directly associated with insulin sensitivity (r = 0.54, P = 0.03). Serum sTNFR1 concentration was also linked to the vasodilatory response to glyceryltrinitrate (P = 0.01). Conversely, TNF-alpha receptor 2 shedding was negatively associated with insulin sensitivity (r = -0.54, P = 0.03), whereas shedding of L-selectin showed no significant association. After exercise-induced lowering of blood pressure, a parallel decrease in sTNFR2/sTNFR1 was observed in DM-2 patients. Our findings suggest that insulin resistance and blood pressure are linked to altered shedding of TNF-alpha receptors in DM-2. The latter seems reversible and is not genetically determined.  相似文献   

9.
TNF-alpha, leptin, and lymphocyte function in human aging   总被引:2,自引:0,他引:2  
Aging is associated with increased inflammatory activity and concomitant decreased T cell mediated immune responses. Leptin may provide a link between inflammation and T cell function in aging. The aim of the study was to investigate if plasma levels of tumor necrosis factor (TNF)-alpha were associated with leptin, circulating interleukin-2 receptors (sIL-2R), and phytohaemagglutinin (PHA) induced IL-2 production in whole blood in elderly humans. Circulating levels of TNF-alpha and sIL-2R were higher in elderly humans (N=42) compared to a young control group (N=37) whereas there was no difference with regard to IL-2 production. Furthermore, there were no age-related differences in serum levels of leptin. However, women had higher levels than men. In the elderly people, serum levels of leptin were correlated with TNF-alpha in univariate regression analysis and in a multiple linear regression analysis adjusting for the effect of gender and body mass index. Furthermore, TNF-alpha, but not leptin, was positively correlated to sIL-2R and negatively correlated to IL-2 production. In conclusion, increased plasma levels of TNF-alpha in aging is associated with poor IL-2 production ex vivo and lymphocyte activation in vivo. These associations do not seem to involve leptin.  相似文献   

10.
Visfatin, is a new adipokine, highly expressed in the visceral fat of both mice and humans. To examine whether visfatin is expressed in human peripheral monocyte-enriched mononuclear cells and whether its expression is altered in type 2 diabetes (DM2), we compared 24 DM2 women [17 overweight (BMI >25) and 7 lean (BMI<25)] to 26 healthy women (14 overweight and 12 lean), all premenopausal. Relative visfatin mRNA levels were significantly higher (approximately 3-fold) in DM2 compared to healthy control women (p<0.02), independently of the presence of overweight/obesity. Mononuclear TNF-alpha and IL-6 mRNA expression was also elevated in DM2 compared to control women (p=0.001 and p=0.004, respectively), an increase observed in both lean and overweight DM2 women. By contrast, circulating visfatin, TNF-alpha, and IL-6 levels showed no difference between DM2 and control women, while adiponectin plasma levels were significantly decreased in the DM2 women (p<0.001). Circulating visfatin and TNF-alpha levels did not differ either between the lean and the overweight subgroups of DM2 and control women, while IL-6 plasma levels were significantly higher in both overweight subgroups compared to their lean counterparts. In conclusion, visfatin, TNF-alpha, and IL-6 mRNA expressions are increased in peripheral mononuclear-monocytic cells from women with type 2 diabetes, independent of their BMI, which may enhance the effects of their adipose-derived levels and may contribute to the increased insulin resistance and atherogenic risk of these patients.  相似文献   

11.
The presence of TNF-alpha mRNA and protein in circulating human blood monocytes isolated by continuous Percoll gradient fractionation was studied. The technique of RNA isolation from the blood samples was used to study TNF-alpha mRNA expression. It was shown that human blood monocytes of healthy donors contained no presynthesized pool of TNF-alpha mRNA as well as no TNF-alpha protein.  相似文献   

12.

Background and Aims

The innate immune cells can not normally respond to the pathogen in patients with decompensated cirrhosis. Previous studies reported that antigen-presenting cells take up L-Cystine (L-Cys) and secrete substantial amounts of L-Glutamate (L-Glu) via the transport system Xc- (4F2hc+xCT), and that this exchange influences the immune responses. The aim of this study is to investigate the influence of the plasma L-Cys/L-Glu imbalance observed in patients with advanced cirrhosis on the function of circulating monocytes.

Methods

We used a serum-free culture medium consistent with the average concentrations of plasma amino acids from patients with advanced cirrhosis (ACM), and examined the function of CD14+ monocytes or THP-1 under ACM that contained 0–300 nmol/mL L-Cys with LPS. In patients with advanced cirrhosis, we actually determined the TNF-alpha and xCT mRNA of monocytes, and evaluated the correlation between the plasma L-Cys/L-Glu ratio and TNF-alpha.

Results

The addition of L-Cys significantly increased the production of TNF alpha from monocytes under ACM. Monocytes with LPS and THP-1 expressed xCT and a high level of extracellular L-Cys enhanced L-Cys/L-Glu antiport, and the intracellular GSH/GSSG ratio was decreased. The L-Cys transport was inhibited by excess L-Glu. In patients with advanced cirrhosis (n = 19), the TNF-alpha and xCT mRNA of monocytes were increased according to the Child-Pugh grade. The TNF-alpha mRNA of monocytes was significantly higher in the high L-Cys/L-Glu ratio group than in the low ratio group, and the plasma TNF-alpha was significantly correlated with the L-Cys/L-Glu ratio.

Conclusions

A plasma L-Cys/L-Glu imbalance, which appears in patients with advanced cirrhosis, increased the TNF-alpha from circulating monocytes via increasing the intracellular oxidative stress. These results may reflect the immune abnormality that appears in patients with decompensated cirrhosis.  相似文献   

13.
小鼠血浆TNF—α、NO、NOS水平与脑不对策的关系   总被引:2,自引:0,他引:2  
Fu QL  Li KS 《生理学报》2002,54(6):513-518
研究脑不对称对单核巨噬细胞 (Mo/MФ)的影响。选用雌性 4周龄Balb/c健康小鼠 ,用伸爪取食法根据右利分将小鼠区分为左利、右利和双利三组。细菌脂多糖 (lipopolysaccharide ,LPS)腹腔注射两小时后取血浆检测肿瘤坏死因子 α(TNF α)、一氧化氮 (NO)、一氧化氮合酶 (NOS)水平。结果显示 :( 1)各组间血浆TNF α和NO、NOS水平的变化 :正常生理组NO水平为双利组高于左利组 (P <0 0 5 ) ;LPS刺激后双利组和右利组血浆TNF α水平高于左利组 (P <0 0 5 ) ,NO水平为双利组高于右利组 (P <0 0 1)和左利组 (P <0 0 5 ) ,NOS水平在三组小鼠间无明显差别。 ( 2 )血浆TNF α、NO、NOS与右利分有一定的相关关系 ,各项指标随右利分的变化趋势多为双利>右利和左利 ,形成一以双利分段 (右利分为 2 1~ 2 9)为高峰的弓形向上的曲线 ,随右利分的增加或减少曲线向两侧延伸和下降。上述结果提示 ,脑不对称小鼠单核 /巨噬细胞功能存在差异。脑不对称对免疫功能的影响程度与右利分有关 ,各免疫指标随右利分的变化趋势多为一以双利分段为高峰的弓形向上的曲线  相似文献   

14.
This study compared the results of tumour necrosis factor alpha (TNF-alpha), interleukin-2 soluble receptor (sIL-2R), nitric oxide metabolites (NO(x)), C-reactive protein (CRP), and lipids (total cholesterol, high-density lipoprotein (HDL-cholesterol), low-density lipoprotein (LDL-cholesterol), and triglycerides) between control group (nondiabetic subjects) and overweight type 2 DM subjects. To restrict the influence of variables that could interfere in the interpretation of data, subjects with obesity and/or acute or chronic inflammatory disease, haemoglobinopathies, recent use of antibiotics, antiinflammatory drugs, and trauma were excluded. Type 2 DM patients (n = 39; age 53.3 +/- 9.0 years; median glycated haemoglobin A(1c)< 8%) presented higher levels of TNF-alpha, triglycerides (P < .01), NO(x) and sIL-2R (P < .05) than control group (n = 28; age 39.7 +/- 14.1 years). CRP, LDL-cholesterol, total cholesterol, and HDL-cholesterol did not differ among groups. Diabetic women (n = 21) had higher levels of TNF-alpha, total cholesterol, LDL-cholesterol, and HDL-cholesterol than diabetic men (n = 18) (P < .05), but there were no differences among sexes in the control group. This study indicates that increased level of proinflammatory markers occurs in type 2 DM even in the absence of obesity and marked hyperglycaemia, confirming that the inflammation course of the atherosclerotic process is more severe in diabetic patients than in nondiabetic subjects.  相似文献   

15.
16.
Jain SK  Kannan K  Prouty L  Jain SK 《Cytokine》2004,26(3):102-105
The Women Health Initiative Clinical trial results suggest that post-menopausal women receiving estrogen + progesterone are at risk for heart disease compared with estrogen alone supplemented women. We examined the hypothesis that progesterone but not 17beta-estradiol (E) increases the secretion of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha. U937 human monocytes were cultured with normal or high glucose in the presence and absence of estrogen or progesterone at 37 degrees C for 24 h. Results show that estrogen inhibits IL-6 but not TNF-alpha secretion (p < 0.05) in monocytes activated by lipopolysaccharide (LPS) or high glucose. In addition, progesterone increased the TNF-alpha secretion in activated monocytes. Thus, progesterone supplementation along with estrogen may increase blood levels of pro-inflammatory cytokine TNF-alpha and thus risk of heart disease in post-menopausal women.  相似文献   

17.
18.
Leptin is capable of modulating the immune response. Proinflammatory cytokines induce leptin production, and we now demonstrate that leptin can directly activate the inflammatory response. RNA expression for the leptin receptor (Ob-R) was detectable in human PBMCs. Ob-R expression was examined at the protein level by whole blood flow cytometry using an anti-human Ob-R mAb 9F8. The percentage of cells expressing leptin receptor was 25 +/- 5% for monocytes, 12 +/- 4% for neutrophils, and 5 +/- 1% for lymphocytes (only B lymphocytes). Incubation of resting PBMCs with leptin induced rapid expression of TNF-alpha and IL-6 mRNA and a dose-dependent production of TNF-alpha and IL-6 by monocytes. Incubation of resting PBMCs with high-dose leptin (250 ng/ml, 3-5 days) induced proliferation of resting cultured PBMCs and their secretion of TNF-alpha (5-fold), IL-6 (19-fold), and IFN-gamma (2.5-fold), but had no effect on IL-4 secretion. The effect of leptin was distinct from, and additive to, that seen after exposure to endotoxin or activation by the mixed lymphocyte reaction. In conclusion, Ob-R is expressed on human circulating leukocytes, predominantly on monocytes. At high doses, leptin induces proinflammatory cytokine production by resting human PBMCs and augments the release of these cytokines from activated PBMCs in a pattern compatible with the induction of Th1 cytokines. These results demonstrate that leptin has a direct effect on the generation of an inflammatory response. This is of relevance when considering leptin therapy and may partly explain the relationship among leptin, proinflammatory cytokines, insulin resistance, and obesity.  相似文献   

19.
TNF-alpha is a mediator of lethality in experimental infections by group B streptococcus (GBS), an important human pathogen. Little is known of signal transduction pathways involved in GBS-induced TNF-alpha production. Here we investigate the role of mitogen-activated protein kinases (MAPKs) and NF-kappa B in TNF-alpha production by human monocytes stimulated with GBS or LPS, used as a positive control. Western blot analysis of cell lysates indicates that extracellular signal-regulated kinase 1/2 (ERK 1/2), p38, and c-Jun N-terminal kinase MAPKs, as well as I kappa B alpha, became phosphorylated, and hence activated, in both LPS- and GBS-stimulated monocytes. The kinetics of these phosphorylation events, as well as those of TNF-alpha production, were delayed by 30-60 min in GBS-stimulated, relative to LPS-stimulated, monocytes. Selective inhibitors of ERK 1/2 (PD98059 or U0126), p38 (SB203580), or NF-kappa B (caffeic acid phenetyl ester (CAPE)) could all significantly reduce TNF-alpha production, although none of the inhibitors used alone was able to completely prevent TNF-alpha release. However, this was completely blocked by combinations of the inhibitors, including PD98059-SB203580, PD98059-CAPE, or SB203580-CAPE combinations, in both LPS- and GBS-stimulated monocytes. In conclusion, our data indicate that the simultaneous activation of multiple pathways, including NF-kappa B, ERK 1/2, and p38 MAPKs, is required to induce maximal TNF-alpha production. Accordingly, in septic shock caused by either GBS or Gram-negative bacteria, complete inhibition of TNF-alpha release may require treatment with drugs or drug combinations capable of inhibiting multiple activation pathways.  相似文献   

20.
The aim of this study is to gain further insights into the possible nutraceutical effect on redox balance via thioredoxin (Trx) modulation and on the intrinsic susceptibility of monocytes to generate an inflammatory response. The study group consisted of thirty-two patients with compensated Child A-C, HCV-related cirrhosis. The patients were supplemented for 6 months with 6g/day of a certified fermented papaya preparation (FPP). Fifteen unsupplemented, age/gender-matched healthy subjects served as controls. The patients filled in a detailed diet-life style questionnaire, and blood samples were collected to test routine biochemistry, Trx, redox status (GSH, GSSG, GSH/GSSG ratio, 4-HNE and alpha-tocopherol). Moreover, isolated monocytes were tested for ex-vivo LPS-stimulated TNF-alpha production and TNF-alpha mRNA. As compared to control, patients with liver cirrhosis showed a significantly higher serum level of Trx. A significant correlation occurred with GSH/GSSG ratio in Child B and C patients. FPP supplementation brought about a significant reduction of Trx with levels comparable to the ones of healthy controls. Ten patients Child C (31.2 percent) showed borderline low levels of alpha-tocopherol while all cirrhotic patients, as a whole, showed a significantly abnormal redox balance. Supplementation with FPP did not modify alpha-tocopherol depletion but significantly improved redox balance parameters. Patients with liver cirrhosis showed a significantly upregulated TNF-alpha production in a time-dependent manner and this effect was more pronounced in more advanced stages of the disease and showed a significant correlation with alpha-tocopherol level. Supplementation with FPP significantly, although partially, downregulated TNF-alpha production from monocytes. Taken altogether, it would appear that the typical oxidative-inflammatory biochemical milieu of these patients is mirrored by a significant TNF-alpha upregulation at a monocyte level while a targeted nutraceutical might be a potentially amenable intervention to be part of validated scheduled treatments.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号