阴道分泌物检测胰岛素样生长因子结合蛋白-1诊断胎膜早破的临床价值

目的采用免疫层析法检测阴道分泌物中胰岛素样生长因子结合蛋白-1(IGFBP-1),评价其诊断胎膜早破的临床价值。方法使用阴道液涂片镜检、pH试纸、IGFBP-1检测试剂盒分别对113例入院时临床确诊为胎膜早破的患者、113例未胎膜早破的者和236例入院时临床疑诊为胎膜早破的患者进行检测,并将结果行统计学分析。结果 IGFBP-1检测法的灵敏度、特异性、准确度分别为97.3%、98.2%、97.8%,pH试纸的灵敏度、特异性、准确度分别为81.4%、90.3%、85.8%,涂片镜检的灵敏度、特异性、准确度分别为65.5%、100.0%、82.7%。IG-FBP-1检测法的灵敏度与其余两种方法相比,差异有统计学意义(P<0.01)。结论 IGFBP-1检测法较pH试纸法和涂片镜检法有更高的准确性和特异性,诊断胎膜早破可靠,适合临床推广。     

Amblyomma americanum tick saliva serine protease inhibitor 6 is a cross‐class inhibitor of serine proteases and papain‐like cysteine proteases that delays plasma clotting and inhibits platelet aggregation

We previously demonstrated that Amblyomma americanum tick serine protease inhibitor 6 (AamS6) was secreted into the host during tick feeding and that both its mRNA and protein were ubiquitously and highly expressed during the first 3 days of tick feeding. This study demonstrates that AamS6 is a cross‐class inhibitor of both serine‐ and papain‐like cysteine proteases that has apparent antihaemostatic functions. Consistent with the typical inhibitory serpin characteristics, enzyme kinetics analyses revealed that Pichia pastoris‐expressed recombinant (r) AamS6 reduced initial velocities of substrate hydrolysis (V₀) and/or maximum enzyme velocity (V_max) of trypsin, chymotrypsin, elastase, chymase, and papain in a dose–response manner. We speculate that rAamS6 inhibited plasmin in a temporary fashion in that while rAamS6 reduced V₀ of plasmin by up to ～53%, it had no effect on V_max. Our data also suggest that rAmS6 has minimal or no apparent effect on V₀ or V_max of thrombin, factor Xa, and kallikrein. We speculate that AamS6 is apparently involved in facilitating blood meal feeding in that various amounts of rAamS6 reduced platelet aggregation by up to ～47% and delayed plasma clotting time in the recalcification time assay by up to ～210 s. AamS6 is most likely not involved with the tick's evasion of the host's complement defense mechanism, in that rAamS6 did not interfere with the complement activation pathway. Findings in this study are discussed in the context of expanding our understanding of tick proteins that control bloodmeal feeding and hence tick‐borne disease transmission by ticks.     

Association of circulating insulin‐like growth factor 1 with hepatocellular carcinoma: one cross‐sectional correlation study

Deregulation of insulin‐like growth factor‐1 (IGF‐1) has been implicated in the pathogenesis of several malignancies. This study aimed to investigate the association of changes in circulating IGF‐1 with hepatocellular carcinoma (HCC). The radioimmunoassay was used to analyze serum IGF‐1 levels of 65 HCC patients and 165 healthy subjects. Serum IGF‐1 levels were significantly decreased in the HCC patients as compared with the healthy subjects (158.46±105.07 vs. 247.63±149.96 ng/mL, P<0.001). Furthermore, insulin resistance was significantly higher in the HCC patients than the healthy subjects (P=0.027). In addition, the significant correlations of serum IGF‐1 levels with age and insulin resistance in the healthy subjects were not noted in the HCC patients. Intriguingly, individuals with hepatitis C virus (HCV), not hepatitis B virus, had remarkably decreased IGF‐1 levels in both groups of the HCC patients and healthy subjects. Moreover, in the HCV subgroup, serum IGF‐1 levels were significantly reduced in the HCC patients than the healthy subjects (113.14±71.28 vs. 172.42±74.02 ng/mL, P=0.003). In conclusion, decreased serum IGF‐1 levels were associated with HCC and the decrease was remarkably noted in those patients concomitant with chronic hepatitis C. J. Clin. Lab. Anal. 24:195–200, 2010. © 2009 Wiley‐Liss, Inc.     

MicroRNA miR‐8 regulates multiple growth factor hormones produced from Drosophila fat cells

Metabolic organs such as the liver and adipose tissue produce several peptide hormones that influence metabolic homeostasis. Fat bodies, the Drosophila counterpart of liver and adipose tissues, have been thought to analogously secrete several hormones that affect organismal physiology, but their identity and regulation remain poorly understood. Previous studies have indicated that microRNA miR‐8, functions in the fat body to non‐autonomously regulate organismal growth, suggesting that fat body‐derived humoral factors are regulated by miR‐8. Here, we found that several putative peptide hormones known to have mitogenic effects are regulated by miR‐8 in the fat body. Most members of the imaginal disc growth factors and two members of the adenosine deaminase‐related growth factors are up‐regulated in the absence of miR‐8. Drosophila insulin‐like peptide 6 (Dilp6) and imaginal morphogenesis protein‐late 2 (Imp‐L2), a binding partner of Dilp, are also up‐regulated in the fat body of miR‐8 null mutant larvae. The fat body‐specific reintroduction of miR‐8 into the miR‐8 null mutants revealed six peptides that showed fat‐body organ‐autonomous regulation by miR‐8. Amongst them, only Imp‐L2 was found to be regulated by U‐shaped, the miR‐8 target for body growth. However, a rescue experiment by knockdown of Imp‐L2 indicated that Imp‐L2 alone does not account for miR‐8's control over the insect's growth. Our findings suggest that multiple peptide hormones regulated by miR‐8 in the fat body may collectively contribute to Drosophila growth.     

IGF-1, IGFBP-3, VEGF and MMP-9 levels and their potential relationship with renal functions in patients with compensatory renal growth

BACKGROUND: Mechanisms of compensatory renal growth (CRG) still remain a mystery. Various growth factors, including growth hormone, insulin-like growth factor-1 (IGF-1) have been implicated in different forms of CRG. AIMS: To investigate the serum levels of IGF-1, vascular endothelial growth factor (VEGF - role in vascular remodelling), matrix metalloproteinase-9 (MMP-9 - essential for normal nephrogenesis) and correlation of renal function in patients with unilateral nephrectomized, agenesis and hypoplasic kidney. METHODS: Thirty patients were included in this study. In group I, there were 10 patients with unilateral nephrectomy, while in group II, there were 10 patients with unilateral agenesis. As for group III, there were 10 patients with unilateral hypoplastic kidney. The serum levels of IGF-1, IGF-binding protein-3 (IGFBP-3), VEGF and MMP-9 were studied in all the cases. Clearance of creatinin (Ccr) and protein excretion were examined in the 24 h urine. CRG was determined with ultrasonography and scintigraphy. Twenty-six control subjects were also studied. RESULTS: The levels of IGF-1, IGFBP-3, VEGF and MMP-9 were significantly higher in patients than in the control subjects (P < 0.001). Ccr and protein excretion levels were different in study groups than in those of the control group (P < 0.01). There were positive correlations between the serum levels of IGF-1 with IGFBP-3; IGF-1 with MMP-9; IGFBP-3 with MMP-9 (r = 0.825, P = 0.0001; P < 0.001 r = 0.611; P < 0.001 r = 0.585, respectively). There were negative correlations between GFR and the serum levels of IGF-1, IGFBP-3 and MMP-9 (P < 0.01 r = -0.708; P = 0.002 r = -0.803; P < 0.05 r = -0.442, respectively). Furthermore, there were positive correlations between proteinuria and the serum levels of IGF-1, IGFBP-3 and MMP-9 (P = 0.039 r = 0.600; P < 0.05 r = 0.456; P < 0.05 r = 0.424). CONCLUSIONS: Increased IGF-1, IGFBP-3, VEGF and MMP-9 were observed in CRG in the follow-up period. IGF-1 and MMP-9 seemed to have increased in patients with CRG in defiance of the development of fibrosis. Moreover, IGF-1 and MMP-9 seem to be associated with reduced renal function and proteinuria.     

胆红素脑病新生儿血胰岛素样生长因子-1水平的变化及意义

目的探讨胆红素脑病新生儿血清胰岛素样生长因子-1（IGF-1）水平与脑损伤相关性及临床意义。方法研究对象为2009年9月至2012年3月胆红素脑病新生儿36例、足月正常新生儿32例,采用酶联免疫吸附试验（ELISA）检测血清IGF-1水平,对两组新生儿血清IGF-1水平进行比较;同步检测两组患儿间接胆红素水平进行比较。结果胆红素脑病患儿组血清IGF-1浓度为36．12±6．28ng／ml,较正常对照组78．65±17．51ng／ml降低,两组比较差异有统计学意义（P〈0．05）。结论胆红素脑病患儿血清IGF-1浓度显著降低可能与脑损伤密切相关,检测血清IGF-1水平对判断胆红素脑病患儿脑损伤具有临床参考价值。     

IGFBP-rP1、BDNF及TrkB在子宫内膜癌中的表达及临床意义

目的探讨胰岛素样生长因子结合蛋白相关蛋白1(IGFBP-rP1)、脑源性神经营养因子(BDNF)及酪氨酸受体激酶B(TrkB)在子宫内膜癌中的表达,以及三者与子宫内膜癌临床病理特征的关系。方法选取102例子宫内膜癌患者作为研究对象,以40例正常子宫内膜组织作为对照,所有患者术前均未接受放化疗治疗;应用免疫组织化学Envison法检测IGFBP-rP1、BDNF和TrkB的阳性表达,分析三者与子宫内膜癌临床病理特征的关系,以及三者阳性表达之间的相关性。结果IGFBP-rP1、BDNF及TrkB在子宫内膜癌中的表达率分别为56.86%(58/102)、46.08%(47/102),49.02%(50/102)均高于在正常子宫内膜组织中的阳性表达率20.00%(8/40)、22.50%(9/40)、17.50%(7/40),差异均有统计学意义(χ²分别=15.74、6.69、11.93,P均<0.05);IGFBP-rP1、BDNF和TrkB的阳性表达均与内膜癌临床分期、细胞分级有关(χ²分别=4.03、4.51、5.31、5.06、6.30、7.81,P均<0.05);IGFBP-rP1在淋巴结转移组中表达率为100%(9/9),在无淋巴结转移组阳性表达率为52.69%(49/93),差异有统计学意义(χ²=3.88,P<0.05);BDNF和TrkB阳性表达率在淋巴结转移组和无淋巴结转移组中比较,差异无统计学意义(χ²分别=2.85、2.59,P均>0.05)。相关分析显示,BDNF阳性表达与TrkB阳性表达呈正相关(r=0.42,P<0.05),IGFBP-rP1阳性表达与BDNF、TrkB阳性表达均呈正相关(r分别=0.52、0.58,P均<0.05)。结论IGFBP-rP1可能通过BDNF/TrkB信号通路参与子宫内膜癌的发生发展。     

Exenatide upregulates gene expression of glucagon‐like peptide‐1 receptor and nerve growth factor in streptozotocin/nicotinamide‐induced diabetic mice

Glucagon‐like peptide‐1 (GLP‐1) is an incretin hormone that has modulating effects on insulin release. GLP‐1 and receptors for GLP‐1 are widely expressed throughout the body including the brain. The expression of GLP‐1 receptors is very specific to large neurons in hippocampus, neocortex, and cerebellum. GLP‐1 receptor stimulation enhances glucose‐dependent insulin secretion and lowers blood glucose in type 2 diabetes mellitus. Studies on adipobiology of neurotrophins have focused on nerve growth factor (NGF) as an example of adipose‐derived neurotrophins. Compromised trophic factor signaling may underlie neurodegenerative diseases ranging from Alzheimer's disease to diabetic neuropathies. Exenatide, a potent and selective agonist for the GLP‐1 receptor, is currently approved for the treatment of type 2 diabetes mellitus. The aim of this study was to assess the effect of chronic exenatide treatment on the hippocampal gene expression levels of GLP‐1 receptor and NGF in diabetic mice. The effects of chronic exenatide treatment (0.1 μg/kg, s.c., twice daily for 2 weeks) on GLP‐1 receptor and NGF gene expression levels in the hippocampus of streptozotocin/nicotinamide (STZ–NA)‐induced diabetic mice were assessed by quantitative real‐time polymerase chain reaction (RT‐PCR). The results of this study revealed that hippocampal gene expression of GLP‐1 receptor and NGF were downregulated in diabetic mice. Importantly, a significant increase in the gene expression level of GLP‐1 receptor and NGF was determined after 2 weeks of exenatide administration. Increased gene expression level of GLP‐1 receptor and NGF may underlie the beneficial action of exenatide in STZ/NA‐induced diabetes.     

A collagen cardiac patch incorporating alginate microparticles permits the controlled release of hepatocyte growth factor and insulin‐like growth factor‐1 to enhance cardiac stem cell migration and proliferation

Cardiac stem cells (CSCs) represent a logical cell type to exploit as a regenerative treatment option for tissue damage accrued as a result of a myocardial infarction. However, the isolation and expansion of CSCs prior to cell transplantation is time consuming, costly and invasive, and the reliability of cell expansion may also prove to be a major obstacle in the clinical application of CSC‐based transplantation therapy after a myocardial infarction. In order to overcome this, we propose the incorporation of growth factor‐eluting alginate microparticles into collagen‐based scaffolds as an implantable biomaterial to promote the recruitment and expansion of CSCs in the myocardium. In order to obtain scaffolds able to enhance the motogenic and proliferative potential of CSCs, the aim of this work was to achieve a sustained delivery of both hepatocyte growth factor and insulin‐like growth factor‐1. Both proteins were initially encapsulated in alginate microparticles by spray drying and subsequently incorporated into a collagen scaffold. Microparticles were seen to homogeneously distribute through the interconnected scaffold pore structure. The resulting scaffolds were capable of extending the release of both proteins up to 15 days, a three‐fold increase over non‐encapsulated proteins embedded in the scaffolds. In vitro assays with isolated CSCs demonstrated that the sustained release of both bioactive proteins resulted in an increased motogenic and proliferative effect. As presently practiced, the isolation and expansion of CSCs for autologous cell transplantation is slow, expensive and difficult to attain. Thus, there is a need for strategies to specifically activate in situ the intrinsic cardiac regenerative potential represented by the CSCs using combinations of growth factors obviating the need for cell transplantation. By favouring the natural regenerative capability of CSCs, it is hypothesized that the cardiac patch presented here will result in positive therapeutic outcomes in MI and heart failure patients in the future. Copyright © 2016 John Wiley & Sons, Ltd.     

静脉高压导致的剪应力改变在载脂蛋白A-1结合蛋白调控血管内皮生长因子表达中的作用

目的：探讨静脉高压对大鼠上矢状窦的血流剪应力作用，以及载脂蛋白A-1结合蛋白（apoA-I binding protein,AIBP）介导的血管新生作用及潜在机制。方法：建立不同静脉压力梯度的大鼠模型（4组）：A组大鼠行右侧颈动脉-颈外静脉吻合术+左侧横窦闭塞术+顶骨磨除术；B组大鼠行右侧颈动脉-颈外静脉吻合术+顶骨磨除术；C组大鼠行右侧颈动脉结扎术+右侧颈外静脉结扎术+顶骨磨除术；D组大鼠行顶骨磨除术。测量并计算3个月后上矢状窦剪应力。用Western印迹法、real-timePCR及免疫组化检测硬膜组织中AIBP、血管内皮生长因子（vascular endothelial growth factor,VEGF）的表达情况。将人脐静脉内皮细胞(human umbilical vein endothelial cell，HUVEC)分别于不同剪应力环境下培养后，检测细胞中AIBP、VEGF的表达及总胆固醇的含量。结果：静脉高压大鼠模型上矢状窦血流剪应力较D组明显增大（P<0.05），且剪应力改变与静脉端压力正相关。real-timePCR和Western印迹显示，与D组相比，A组和B组大鼠硬脑膜中AIBP的表达下调、VEGF表达上调（P<0.01）。免疫组化结果示，AIBP在硬膜血管全层均有表达。体外实验中，HUVEC在高剪应力环境中与低剪应力环境下相比，AIBP表达量下调、VEGF表达上调、总胆固醇含量升高（P<0.05）。结论：静脉端压力升高可导致上矢状窦内血流剪应力增大，抑制AIBP的表达，减少细胞膜上胆固醇的流出，促进VEGF介导的血管新生。     

胰岛素样生长因子 1在神经特异性再生中的作用机制

目的 研究胰岛素样生长因子 1( IGF 1) 对神经元 p75受体表达的影响,探讨 IGF 1在神经特异性再生中的作用机制.方法在体外培养神经元培养基中加入不同浓度的重组 IGF 1, 用粘附式细胞仪检测神经元表面神经生长因子 p75受体的表达.结果 IGF 1作用后神经元 p75受体的表达增加,细胞表面 p75受体的增加与 IGF 1的浓度在一定范围内呈现量效关系.结论 IGF 1 在体外培养条件下可增加神经细胞表面 p75受体的表达,IGF 1的神经营养作用机制可能与 p75受体表达上调有关 .     

Enhancement of periosteal bone formation by basic fibroblast‐derived growth factor containing polycystic kidney disease and collagen‐binding domains from Clostridium histolyticum collagenase

Recombinant basic fibroblast growth factor (bFGF) is a potent mitogen for mesenchymal cells that accelerates bone union and repair when applied locally at defect sites. However, because bFGF diffuses rapidly from bone defect sites, repeated dosing is required for sustained therapeutic effect. We previously fused the collagen‐binding domain (CBD) and polycystic kidney disease (PKD) domain of Clostridium histolyticum class II collagenase (ColH) to bFGF and demonstrated that the fusion protein markedly enhances bone formation when loaded onto collagen materials used for grafting. However, systemic injection of a fusion protein consisting of parathyroid hormone (PTH) and a CBD was shown to accelerate bone formation in an osteoporosis model more rapidly than treatment with a PTH–PKD–CBD fusion protein. Here, we compared the biological properties of two collagen‐binding forms of bFGF, bFGF–CBD and bFGF–PKD–CBD. Both fusion proteins promoted the in vitro proliferation of periosteal mesenchymal cells, indicating that they had biological activity similar to that of native bFGF. In vivo periosteal bone formation assays in rat femurs showed that both bFGF–CBD and bFGF–PKD–CBD induced periosteal bone formation at higher rates than collagen sheet alone and bFGF. However, bFGF–PKD–CBD markedly enhanced bone formation and had higher collagen‐binding ability than bFGF–CBD in in vitro protein release assays. Taken together, these results suggest that the PKD domain increases the retention of bFGF at graft sites by enhancing collagen‐binding affinity. Therefore, bFGF–PKD–CBD–collagen composite appears to be a promising material for bone repair in the clinical setting. Copyright © 2015 John Wiley & Sons, Ltd.     

Protein kinase C‐δ mediates von Willebrand factor secretion from endothelial cells in response to vascular endothelial growth factor (VEGF) but not histamine

Summary. Background: Vascular endothelial growth factor (VEGF) and histamine induce von Willebrand factor (VWF) release from vascular endothelial cells. Protein kinase C (PKC) is involved in the control of exocytosis in many secretory cell types. Objectives: We investigated the role of PKC and the interactions between PKC and Ca²⁺ signaling in both VEGF‐induced and histamine‐induced VWF secretion from human umbilical vein endothelial cells (HUVECs). Results: Several PKC inhibitors (staurosporine, Ro31‐8220, myristoylated PKC peptide inhibitor and Go6983) block VEGF‐induced but not histamine‐induced VWF secretion. PKC‐α and novel PKCs (PKC‐δ, PKC‐ε, and PKC‐η), but not PKC‐β, are expressed in HUVECs. Both VEGF and histamine activate PKC‐δ. However, gene inactivation experiments using small interfering RNA indicate that PKC‐δ (but not PKC‐α) is involved in the regulation of VEGF‐induced but not histamine‐induced secretion. Both VEGF and histamine induce a rise in cytosolic free Ca²⁺ ([Ca²⁺]_c), but the response to VEGF is weaker and even absent in a significant subset of cells. Furthermore, VEGF‐induced secretion is largely preserved when the rise in [Ca²⁺]_c is prevented by BAPTA‐AM. Conclusions: Our study identifies striking agonist specificities in signal–secretion coupling. Histamine‐induced secretion is dependent on [Ca²⁺]_c but not PKC, whereas VEGF‐induced secretion is largely dependent on PKC‐δ and significantly less on [Ca²⁺]_c. Our data firmly establish the key role of PKC‐δ in VEGF‐induced VWF release, but suggest that a third, VEGF‐specific, signaling intermediate is required as a PKC‐δ coactivator.