Increased serum levels of insulin-like growth factor (IGF)-1 and IGF-binding protein-3 in Henoch-Schonlein purpura

beta-Phenylethylamine (beta-PEA), an endogenous amine synthesized in the brain, serves as a neuromodulator and is involved in the pathophysiology of various neurological disorders such as depression, schizophrenia, and attention-deficit hyperactivity disorder. beta-PEA fully exerts the physiological effects within the nanomolar concentration range via the trace amine receptors, but beta-PEA also causes convulsions at much higher concentrations via an as yet unknown mechanism. To investigate the electrophysiological mechanism by which beta-PEA induces convulsions, we examined the effect of beta-PEA on ionic currents passing through the cell membrane of dissociated rat cerebral cortical neurons, using a patch-clamp technique. The external application of beta-PEA suppressed ionic currents which continuously flowed when the membrane potential was held at -25 mV. The suppression was in a concentration-dependent manner and a half-maximal effective concentration was 540 muM. These currents suppressed by beta-PEA consisted of two K(+) currents: a time- and voltage-dependent K(+) current (M-current) and a leakage K(+) current. The suppression of the M-current reduces the efficacy of the current in limiting excessive neuronal firing, and the suppression of the leakage K(+) current can cause membrane depolarization and thus promote neuronal excitation. Reducing both of these currents in concert may produce neuronal seizing activity, which could conceivably underlie the convulsions induced by high-dose beta-PEA.     

应用胰岛素样生长因子结合蛋白-1预测胎膜早破60例分析

目的 :探讨宫颈分泌物中的脱磷酸化的胰岛素样生长因子结合蛋白 -1(IGFBP -1)在胎膜早破预测中的意义。方法 :应用免疫层析法检测 60例胎膜早破孕妇宫颈阴道分泌物中脱磷酸化的IGFBP -1的含量。结果 :胎膜早破组 ,正常孕妇组IGFBP-1的阳性率分别为 98 3 %和 8 3 %两组结果相比 ,差异有统计学意义 (P <0 0 5 )。结论 :检测宫颈阴道分泌物中的IGFBP -1是诊断胎膜早破快速、准确的方法     

胰岛素样生长因子结合蛋白-5在肝硬化、原发性肝癌患者肝组织和血清中的水平及临床意义

目的观察肝硬化、原发性肝癌患者肝组织和血清中胰岛素样生长因子结合蛋白-5(IGFBP-5)水平,探讨其与肝硬化、原发性肝癌的关系及其临床意义。方法取肝硬化组织、肝癌组织及癌旁正常组织各8例,采用实时RT-PCR技术检测IGFBP-5mRNA的表达水平;取肝硬化(21例)、原发性肝癌(14例)及正常对照者(14例)血清,采用ELISA法检测IGFBP-5水平,分析IGFBP-5在不同分组中水平的差异及其临床意义。结果肝硬化组肝组织中IG-FBP-5mRNA的表达及血清中IGFBP-5水平均较正常对照组降低(P均<0.05),与血清中升高的透明质酸(HA)、层粘连蛋白(LN)和肝功能无相关性。原发性肝癌组肝组织中IGFBP-5的表达及血清中IGFBP-5水平均高于正常对照组和肝硬化组(P均<0.05),与血清中升高的甲胎蛋白(AFP)和肝功能亦无相关性。结论在肝硬化发生后,肝组织表达和合成IGFBP-5减少,与其他细胞因子的调节有关,其可能与HA、LN互补作为诊断早期肝纤维化的一个无创指标;原发性肝癌患者肝组织中IGFBP-5表达增多,血清水平增高,其有可能作为一个潜在的诊断原发性肝癌的检测指标。IGFBP-5与肝硬化、原发性肝癌的关系值得进一步研究。     

Evidence for a mouse mesangial cell-derived factor that stimulates lymphocyte proliferation.

The functions of the glomerular mesangium are served by at least two populations of cells--a cell bearing microfilaments that regulates blood flow, and a phagocytic cell bearing Ia determinants and Fc receptors. We provide evidence that mouse mesangial cells (bearing microfilaments) produce a factor(s) that stimulates spleen cell proliferation. The factor(s) appears to act via monocytes/macrophages, since its stimulatory activity is abrogated by prior depletion of the responding mononuclear cell population of monocytes/macrophages. Confirmation of its action on macrophages was documented by experiments that showed that medium from macrophages incubated with mesangial cell supernatant contained greater amounts of a factor that stimulated [3H]thymidine uptake by macrophage-depleted spleen cell populations. By the cothymocyte proliferation assay, it could be shown that mesangial cell supernatant induced splenic macrophage production of interleukin-1-like activity. Preliminary characterization reveals the factor to have a molecular weight greater than 100,000. Thus, a novel function is delineated for this mesangial cell type that appears capable of modulating the local immune response by providing an amplification signal.     

Serum insulin-like growth factor binding protein-3 as a potential biomarker for diagnosis and prognosis of oesophageal squamous cell carcinoma

BackgroundInsulin-like growth factor binding protein-3 (IGFBP3) has been reported to be related to the risk of some cancers. Here we focussed on serum IGFBP3 as a possible biomarker of diagnosis and prognosis for oesophageal squamous carcinoma (ESCC).MethodsEnzyme-linked immunosorbent assay (ELISA) was used to measure the serum IGFBP3 level in the training cohort including 136 ESCC patients and 119 normal controls and the validation cohort with 55 ESCC patients and 42 normal controls. The receiver operating characteristics curve (ROC) was used to assess the diagnosis value. Cox proportional hazards model was applied to select factors for survival nomogram construction.ResultsSerum IGFBP3 levels were significantly lower in early-stage ESCC or ESCC patients than those in normal controls (p < .05). The specificity and sensitivity of serum IGFBP3 for the diagnosis of ESCC were 95.80% and 50.00%, respectively, with the area under the ROC curve (AUC) of 0.788 in the training cohort. Similar results were observed in the validation cohort (88.10%, 38.18%, and 0.710). Importantly, serum IGFBP3 could also differentiate early-stage ESCC from controls (95.80%, 52.54%, 0.777 and 88.10%, 36.36%, 0.695 in training and validation cohorts, respectively). Furthermore, Cox multivariate analysis revealed that serum IGFBP3 was an independent prognostic risk factor (HR = 2.599, p = .002). Lower serum IGFBP3 level was correlated with reduced overall survival (p < .05). Nomogram based on serum IGFBP3, TNM stage, and tumour size improved the prognostic prediction of ESCC with a concordance index of 0.715.ConclusionWe demonstrated that serum IGFBP3 was a potential biomarker of diagnosis and prognosis for ESCC. Meanwhile, the nomogram might help predict the prognosis of ESCC.

Key Message

• Serum IGFBP3 showed early diagnostic value in oesophageal squamous cell carcinoma with independent cohort validation. Moreover, serum IGFBP3 was identified as an independent prognostic risk factor, which was used to construct a nomogram with improved prognosis ability in oesophageal squamous cell carcinoma.

     

Urine excretion of a monocytic chemotaxic protein-1 and a transforming growth factor beta1 as an indicator of chronic glomerulonephritis progression

AIM: To measure urine and renal tissue levels of profibrogenic mediators (monocytic chemotaxic protein-1-MCP-1 and transforming growth factor beta1 - TGF-b1) in patients with chronic glomerulonephritis (CGN); to specify significance of these mediators for assessment of inflammation and fibrosis in the kidney and as prognosis criteria. ELISA, immunohistochemical tests, morphometry were used to study urine excretion of MCP-1 and TGF-b1, expression of TGF-b1 in renal tissue, interstitial area, respectively, in 63 patients with active proteinuric CGN. RESULTS: Patients with active proteinuric forms of CGN have higher urine excretion of MCP-1 and TGF-b1 than healthy controls. Urine excretion of MCP-1 in patients with nephrotic syndrome was significantly higher than in patients with moderate urinary syndrome. The highest MCP-1 urine excretion was observed in patients with persistent renal failure. Urine excretion of TGF-b1 depended on the level of creatinemia being the highest in marked proteinuria and stable renal dysfunction. Intensive urine excretion of TGF-b1 occurred in CGN patients with expression of this cytokine in renal interstitium. This confirms its local-renal origin. A correlation was found between urine values of MCP-1, TGF-b1 and severity of tubulo-interstitial fibrosis (TIF). High informative value (sensitivity and specificity) of urine MCP-1 and TGF-b1 are for the first time shown as markers of interstitial fibrosis. They are also important for making prognosis of CGN. CONCLUSION: It is shown that MCP-1 and TGF-b1 are essential for remodeling of tubulointerstitium. The urinary parameters mark TIF and can be used as criteria of activity and prognosis of CGN.     

Evidence that endotoxin is the cyclic 3':5'-GMP--promoting factor in erythropoietin preparations.

Since Ep preparations are contaminated with endotoxin, the possibility that the latter might be the factor in crude Ep which increases cGMP levels in rat fetal liver cells was examined. Endotoxin produced a striking elevation of cGMP in rat fetal liver cells without affecting cAMP levels or heme synthesis. Absorption with Limulus lysate of more than 99% of the endotoxin in a crude Ep preparation caused a parallel decrease in the cGMP-promoting activity without reduction of heme synthetic potency. It is concluded that endotoxin is the component of crude Ep which increases cGMP levels in rat fetal liver. The precise role of elevated cGMP in the action of endotoxin on cells and the universality of this effect remain to be determined.     

Regulation of experimental autoimmune encephalomyelitis with insulin-like growth factor (IGF-1) and IGF-1/IGF-binding protein-3 complex (IGF-1/IGFBP3).

Insulin-like growth factor (IGF)-1 is a cytokine that promotes oligodendrocyte development and myelin production. This study investigated whether treatment of chronic, relapsing murine experimental autoimmune encephalomyelitis (EAE) with IGF-1 or IGF-1 associated with its binding protein, IGFBP3, altered the course of disease. Administration of IGF-1/IGFBP3 (1-100 mg/kg per day) delayed the onset of disease in a dose-dependent manner and histologic examination showed a delay in inflammatory cells entering the central nervous system. However, once signs of EAE developed, disease was enhanced in the mice that had been given the highest dose of IGF-1/IGFBP3. Treatment with IGF-1/IGFBP3 after the onset of signs resulted in a severe relapse. Administration of free IGF-1 (10 mg/kg per day) provided mild protection when given before disease onset, but did not significantly alter the course of disease if given after disease onset. Possible mechanisms that could explain the altered disease in IGF-1/IGFBP3-treated mice included (a) IGF-1/IGFBP3 administration delayed the onset of EAE by downregulating ICAM-1 gene expression in the central nervous system, and (b) IGF-1/IGFBP3 treatment of EAE resulted in more severe disease due to enhanced expansion of encephalitogenic T cells. Although IGF-1 may enhance remyelination, these results indicate that administration of IGF-1 associated with IGFBP3 may also accentuate autoimmune demyelinating disease.     

Polymorphisms of insulin-like growth factor binding protein-3 as a predictor for risk and patient survival in esophageal squamous cell carcinoma

Background and purposeGenetic single nucleotide polymorphisms (SNP) play a critical role in the development of esophageal squamous cell carcinoma (ESCC). The aim of this study is to investigate the associations between insulin-like growth factor binding protein-3 (IGFBP-3) gene polymorphisms and ESCC patients risk and survival after definitive chemoradiotherapy (CRT).Materials and methodsWe undertook a case-control study to analyze two IGFBP-3 polymorphisms (rs2854744 A > C and rs2854746 G > C) in an Han Chinese population, by extraction of genomic DNA from the peripheral blood of 110 ESCC patients treated with CRT and 128 control participants, and performed IGFBP-3 genotyping using DNA sequencing.ResultsThe obtained results indicated that overall, no statistically significant association was observed in rs2854746 G > C. However, rs2854744 A > C genotype was at increased risk of ESCCs (P = 0.032; odds ratio (OR) = 1.201, CI 95%:1.014–1.423). Moreover, rs2854744 A > C genotype ESCCs were more significantly common in patients with tumor size of >6 cm than A allele ESCC and in cases of lower T stage. Furthermore, ESCC patients with rs2854744CC genotype have the poorer CRT response and shorter survival time than GG + GC genotype ESCC.ConclusionsIn conclusion, polymorphism in IGFBP-3 rs2854744 A > C might be a potential predictor of ESCC risk and patient survival. Nevertheless, further investigation with a larger sample size is needed to support our results.     

Interleukin-6 functions as an intracellular growth factor in hairy cell leukemia in vitro.

The role of interleukin-6 (IL-6) in the growth of B cell derived hairy cell leukemia (HCL) was characterized. Purified hairy cells (HCs) did not increase DNA synthesis in vitro in response to exogenous IL-6; however, they expressed IL-6 receptor (IL-6R) mRNA and bound directly fluorochrome labeled IL-6. IL-6 mRNA was not detectable in tumor cells by Northern blotting, but was evident using PCR amplification. Although intracytoplasmic IL-6 protein was not demonstrable, HCs did secrete low levels of IL-6. Neutralizing antibody to IL-6 did not inhibit HC DNA synthesis. Since tumor necrosis factor (TNF) is a growth factor for HCL, we determined whether the TNF effect could be IL-6-mediated. TNF markedly augmented in vitro DNA synthesis by HCs. TNF did not alter IL-6R expression or IL-6 binding; however, IL-6 mRNA and IL-6 protein were detectable after 3-d culture of HCs with TNF. In addition, IL-6 secretion by HCs was markedly augmented by TNF. Finally, although neither IL-6 nor anti-IL-6 antibody altered TNF-induced DNA synthesis by HCs, IL-6 antisense oligonucleotide inhibited TNF-induced DNA synthesis and IL-6 secretion by HCs. Therefore, IL-6 does not directly affect the growth of HCL, but rather mediates TNF-induced DNA synthesis via an intracytoplasmic mechanism.     

胰岛素样生长因子结合蛋白3增强子元件(IEE)的生物学特征

背景:在细胞水平,胰岛素样生长因子结合蛋白3竞争性地与胰岛素样生长因子结合阻止了胰岛素样生长因子与其受体结合,从而抑制了胰岛素样生长因子的活性.目的:观察衰老细胞中调节性蛋白质胰岛素样生长因子结合蛋白3的生物学特征.设计、时间及地点:单一样本观察,于2006-09/2007-09在西安交通大学生物医学信息工程教育部重点实验室完成.材料:人胚肿二倍体成纤维细胞(2BS)购于中国生物制品研究所.方法:用Northern的方法显示胰岛素样生长因子结合蛋白3基因的表达在年轻和衰老的2BS细胞中存在差异:聚合酶链反应扩增出人类胰岛素样生长因子结合蛋白3上游包括5'-UTR区的2kb的序列,并用酶切得到4组不同长短的胰岛素样生长因子结合蛋白3启动子片段并确定可调控转录活性的区域;通过重叠寡核苷酸凝胶阻滞实验确定在该活性区域中的增强子元件-IEE(IGFBP-3 enhancerelement)及其与蛋白结合的碱基序列等;用DNase I Footprinting法确定了IEE中与蛋白结合的核心序列.主要观察指标:①胰岛素样生长因子结合蛋白3基因在年轻和衰老细胞中的表达差异.②通过重叠寡核苷酸确定增强子元件.③通过凝胶阻滞试验证实该复合物结合活性与衰老相关的.④通过凝胶阻滞试验确定IEE与蛋白结合的碱基序列.⑤用DNase I Footprinting法确定IEE中与蛋白结合的核心序列.⑥判断与IEE结合蛋白的相对分子质量.结果:与年轻的2BS细胞相比,衰老的2BS细胞中胰岛素样生长因子结合蛋白3基因的表达升高:5'-ccagcctgccaa gca gcg tgcCCCggttgc-3'是胰岛素样生长因子结合蛋白3的增强子元件;该元件与蛋白结合的核心序列是CTG CCA和GCGTGC CCC G,而且这种结合是与衰老相关的:结合蛋白的相对分子质量大约在27 000.结论:在2BS细胞中发现了一个新的转录增强子,它与蛋白结合的核心序列是CTGCCA和GCG TGC CCC G,可与一个大约27 000的蛋白结合:在衰老细胞中可选择性地促进胰岛素样生长因子结合蛋白3的表达.     

Evidence that insulin-like growth factor I increases renal plasma flow and glomerular filtration rate in fasted rats.

The mechanisms whereby growth hormone may increase renal plasma flow (RPF) and GFR are not known, but circumstantial evidence has implicated insulin-like growth factor I (IGF-I) as a mediator of this effect. This study examined whether an infusion of IGF-I will increase RPF and GFR, whether this effect occurs quickly, and if this effect is dependent on eicosanoids or peptide hormones known to affect renal function. Rats fasted for 3 d to reduce IGF-I and IGF-I plasma binding proteins were anesthetized; then the rats received an intravenous injection of 25 micrograms/kg IGF-I, and an infusion of 25 micrograms/kg IGF-I within 20 min. Controls received infusion of the vehicle. RPF (para-aminohippurate clearances), GFR (inulin clearances), renal vascular resistance (RVR), mean arterial blood pressure (MABP), plasma IGF-I, and glucose concentrations were measured repeatedly. At the end of the 20-min infusion, plasma IGF-I tended to be increased in the animals that received IGF-I (P = 0.069), but did not increase in the control rats. IGF-I induced a significant and sustained fall in RVR and rise in RPF and GFR without any change in MABP. A small, transient, but significant decrease in plasma glucose concentrations was observed during IGF-I but not during vehicle infusion. Indomethacin, but not somatostatin, blocked the renal response to IGF-I infusion. Thus, IGF-I infusion increases RPF and GFR and reduces RVR in fasted rats. This effect requires the presence of eicosanoids but does not seem to require other peptide hormones suppressed by somatostatin.     

Proinflammatory functions of vascular endothelial growth factor in alloimmunity

Vascular endothelial growth factor (VEGF), an established angiogenesis factor, is expressed in allografts undergoing rejection, but its function in the rejection process has not been defined. Here, we initially determined that VEGF is functional in the trafficking of human T cells into skin allografts in vivo in the humanized SCID mouse. In vitro, we found that VEGF enhanced endothelial cell expression of the chemokines monocyte chemoattractant protein 1 and IL-8, and in combination with IFN-gamma synergistically induced endothelial cell production of the potent T cell chemoattractant IFN-inducible protein-10 (IP-10). Treatment of BALB/c (H-2d) recipients of fully MHC-mismatched C57BL/6 (H-2b) donor hearts with anti-VEGF markedly inhibited T cell infiltration of allografts and acute rejection. Anti-VEGF failed to inhibit T cell activation responses in vivo, but inhibited intragraft expression of several endothelial cell adhesion molecules and chemokines, including IP-10. In addition, whereas VEGF expression was increased, neovascularization was not associated with acute rejection, and treatment of allograft recipients with the angiogenesis inhibitor endostatin failed to inhibit leukocyte infiltration of the grafts. Thus, VEGF appears to be functional in acute allograft rejection via its effects on leukocyte trafficking. Together, these observations provide mechanistic insight into the proinflammatory function of VEGF in immunity.     

Performance characteristics of the IMMULITE 2000 insulin-like growth factor binding protein-3 assay

BACKGROUND: Insulin-like growth factor binding protein-3 (IGFBP-3) is the chief binding protein for insulin-like growth factors 1 and 2 (IGF-1 and IGF-2). Serum concentrations of IGFBP-3 are regulated by growth hormone (GH) and IGF-1 levels. Serum IGFBP-3 measurements are useful for diagnostic evaluations of short stature in children and acromegaly. METHODS: A IGFBP-3 assay for the IMMULITE 2000 analyzer was evaluated for limit of detection, linearity, intra- and interassay imprecision, comparison to another commercially available assay, interference studies, and an adult reference interval. RESULTS: The limit of detection was 0.006 mg/l. The assay was linear from 0.01 to 15.1 mg/l. The total interassay imprecision was <6% for IGFBP-3 concentrations of 1.1 and 4.4 mg/l. Comparison with a Nichols RIA method showed comparable results. Deming regression analysis gave a slope of 1.02+/-0.02, an intercept of 0.24+/-0.07, and a Sy/x of 0.33 (r=0.98) over the range tested (0.4 to 10.3 mg/l). Interference was <10% for all levels of bilirubin, triglyceride, and hemoglobin tested. The nonparametric reference interval for adults 26 to 61 years was 2.9 to 6.5 ng/ml. CONCLUSIONS: The IMMULITE 2000 IGFBP-3 assay shows acceptable performance and is suitable for routine clinical use.     

Impaired glucose homeostasis in insulin-like growth factor binding protein-1 transgenic mice.

Transgenic mice that overexpressed IGFBP-1 are hyperinsulinemic in the first week of life and gradually develop fasting hyperglycemia. In adult transgenic mice, the hypoglycemic response to IGF-I but not insulin or des (1-3) IGF-I was attenuated (P < 0.05) compared with wild-type mice. Furthermore, in isolated adipocytes from transgenic mice, the stimulatory effect of IGF-I but not insulin on 2-deoxy-[3H]-glucose uptake was reduced (P < 0.02). In contrast, in isolated soleus muscle, the effects of both IGF-I and insulin on 2-deoxy-3H-glucose uptake and on [3H]-glucose incorporation into glycogen were significantly reduced compared to wild-type mice. The decline in specific activity of the 2-deoxy-3H-glucose, a measure of glucose appearance in the circulation, was more marked in transgenic animals (P < 0.05). In addition, tissue uptake of glucose was significantly higher in diaphragm, heart, intestine, liver, soleus muscle, and adipose tissue from fasting transgenic mice. Plasma concentrations of alanine, lysine, and methionine were also elevated in transgenic mice. These data suggest that overexpression of IGFBP-1 attenuates the hypoglycemic effect of endogenous IGF-I, which is initially compensated for by enhanced pancreatic insulin production. However, in adult mice pancreatic insulin content is reduced, insulin resistance is demonstrable in skeletal muscle and fasting hyperglycemia develops.     

IGF-binding protein-1 levels are related to insulin-mediated glucose disposal and are a potential serum marker of insulin resistance

OBJECTIVE: IGF-binding protein (IGFBP)-1 is negatively regulated by insulin. We determined whether the measurement of IGFBP-1 in serum is a useful marker of insulin resistance. RESEARCH DESIGN AND METHODS: Twenty-three subjects underwent a euglycemic insulin clamp. Glucose disposal rates (M) were then correlated with measurements of IGFBP-1, fasting insulin levels, homeostasis model assessment (HOMA), and BMI. RESULTS: IGFBP-1 levels more strongly correlated with M (R = 0.73) than the other parameters such as BMI or HOMA. The level of this protein decreased in individuals who became more insulin sensitive by exercise training. CONCLUSIONS: These studies show a strong correlation between insulin sensitivity and the serum levels of IGFBP-1. These studies suggest, therefore, that measurement of this protein may be valuable in identifying those individuals with insulin resistance and those individuals who respond to interventional strategies.