胰岛素样生长因子结合蛋白、内毒素与肝纤维化

目前胰岛素样生长因子结合蛋白（insulin—like growth—factor—binding protein，IGFBPs）及其超家族功能的研究是国际上的热点。有研究表明IGFBPs与肝纤维化的发生有关，而临床检测和动物实验表明肠源性内毒素血症与肝纤维化的发生发展有着密切关系，同时有研究显示内毒素可诱导循环中某些IGFBPs和其肝脏基因的表达发生变化。     

肝纤维化患者肝组织中胰岛素样生长因子结合蛋白的表达及意义

胰岛素样生长因子结合蛋白（IGFBP）可参与细胞的生长、分化和存活，并在许多生理和病理情况下发挥作用。目前一些研究显示IGFBP可能与纤维化的发生发展有关。Shaarawy等研究表明血清IGFBP3的水平可作为临床上定量评价肝硬化患者肝细胞合成能力的生物学标志。目前认为肝星状细胞（HSC）活化是肝纤维化发生的关键，转化生长因子β1（TGFβ1）是最重要的促纤维化细胞因子。     

坎地沙坦对肝纤维化大鼠Ang-(1-7)的影响

目的研究血管紧张素Ⅱ1型受体拮抗剂坎地沙坦抗大鼠肝纤维化的疗效及对血管紧张素1-7[Ang-(1-7)]的影响。方法制备四氯化碳诱导大鼠肝纤维化模型,同时应用坎地沙坦灌胃,共8周。肝组织进行常规HE与Masson三色染色,并测定门脉压及血清肝功能,血浆中Ang-(1-7)应用酶联免疫方法检测。结果与模型组大鼠比较,坎地沙坦可改善肝纤维化程度及降低门脉压,血浆Ang-(1-7)水平增加。结论坎地沙坦抗肝纤维化可能与升高Ang-(1-7)有关。     

坎地沙坦对慢性心衰大鼠心肌结缔组织生长因子表达的影响

随机选取雄性Wistar大鼠采用腹主动脉缩窄法制作慢性心衰模型，8周后心衰大鼠随机分为心衰对照组和药物干预组，另取大鼠仅分离腹主动脉而不结扎作为假手术组。药物干预组予以坎地沙坦灌胃，心衰对照组和假手术组均用等量生理盐水灌胃。4周时检测血流动力学参数及心室肌中结缔组织生长因子（CTGF）表达。发现药物干预组死亡率显著低于心衰对照组；与心衰对照组比较，药物干预组各血流动力学参数明显改善，药物干预组CTGF表达显著降低（P〈0．01）。提示坎地沙坦可明显改善心功能并抑制心室重塑和心肌纤维化，其抑制心肌纤维化作用可能与CTGF表达降低有关。     

贝那普利对肝纤维化大鼠胰岛素样生长因子-Ⅰ受体的影响

目的研究血管紧张素转换酶抑制剂贝那普利对大鼠肝纤维化模型的疗效,以及对其肝组织胰岛素样生长因子-Ⅰ受体(IGF-ⅠR)的影响.方法取Wistar雄性大鼠42只随机分为3组,正常对照组12只,模型组15只,贝那普利治疗组15只.制备四氯化碳诱导的大鼠肝纤维化模型,同时应用贝那普利灌胃,共8周.对肝组织进行苏木精-伊红染色...     

胰岛素样生长因子Ⅰ与肝纤维化

胰岛素样生长因子I(IGF-I)是体内普遍存在的多肽,循环系统中IGF-I主要来源于肝脏．在垂体生长激素的调控下,IGF-I对多种细胞如成纤维细胞、成骨细胞、平滑肌细胞等的有丝分裂均有调节作用．目前观点认为肝星状细胞(HSC)活化后可分泌大量胶原纤维,是肝纤维化时细胞外基质的主要来源．实验表明 IGF-I能够促进体外培养HSC增殖、活化并抑制其凋亡．而体内研究发现,肝硬化患者血清IGF-I浓度显著下降,外源性小剂量IGF-I 注射能够改善肝功能,为肝纤维化的治疗提供了新的理念．     

肺癌患者胰岛素样生长因子1和胰岛素样生长因子结合蛋白3的表达及其临床意义

目的 分析肺癌患者血清和支气管肺泡灌洗液（BALF）中胰岛素样生长因子1（IGF-1）、胰岛素样生长因子结合蛋白3（IGFBP-3）的表达,探讨其在肺癌诊断和预后中的临床意义.方法 运用免疫放射法检测80例非小细胞肺癌患者和14名健康者（对照组）外周血血清与BALF中IGF-1、IGFBP-3的水平.结果 肺癌组血清和BALF中IGF-1表达显著高于对照组（P＜0.01）,IGFBP-3的表达显著低于对照组（P＜0.05）,同时IGF-1/IGFBP-3升高（P＜0.01）.IGF-1、IGF-1/IGFBP-3在有淋巴结转移、远处转移和TNMⅢ～Ⅳ的肺癌患者血清、BALF中明显高于无转移者和TNMⅠ～Ⅱ期者（P＜0.05）,而IGFBP3下降明显高于无转移者及TNMⅠ～Ⅱ期者（P＜0.05）.肺癌组血清IGF-1、IGFBP-3浓度与BALF中的浓度呈正相关（P ＜0.01）;患者血清BALF中IGF-1与IGFBP-3浓度呈负相关（P＜0.05）.结论 非小细胞肺癌患者血清和支气管肺泡灌洗液中IGF-1、IGFBP-3的表达对肺癌的诊断、判断预后有重要临床意义.     

贝那普利对肝纤维化大鼠胰岛素样生长因子-I受体的影响

目的研究血管紧张素转换酶抑制剂贝那普利对大鼠肝纤维化模型的疗效,以及对其肝组织胰岛素样生长因子-1受体（IGF—IR）的影响。方法取Wistar雄性大鼠42只随机分为3组,正常对照组12只,模型组15只,贝那普利治疗组15只。制备四氯化碳诱导的大鼠肝纤维化模型,同时应用贝那普利灌胃,共8周。对肝组织进行苏木精伊红染色及马松三色染色,观察各组肝纤维化的程度,并测定血清丙氨酸氨基转移酶（ALT）水平,采用SABC免疫组织化学方法检测大鼠肝组织中IGF—IR的表达水平。结果贝那普利治疗组的肝纤维化程度明显较同期模型组轻（P〈0．05）;与对照组相比,模型组体重降低（P〈0．05）及血清ALT升高（P〈0．05）,IGF-IR在肝组织中表达明显增多（P〈0．05）,贝那普利治疗组IGF—IR表达减少（P〈0．05）。结论贝那普利可改善肝纤维化程度,可能与肝组织IGF—IR的表达减少有关。     

老年男性骨质疏松患者血清瘦素、胰岛素样生长因子-1和胰岛素样生长因子结合蛋白-3表达的临床意义

目的观察骨质疏松(OP)老年男性患者血清中瘦素、胰岛素样生长因子(IGF)-1和IGF结合蛋白(IGFBP)-3的表达特征,关注其临床意义。方法 68例OP老年男性患者作为观察组,38例正常骨密度、无明显器质性疾病的老年男性作为对照组。抽取两组的空腹静脉血,检测血清中瘦素、IGF-1和IGFBP-3的表达。结果观察组中瘦素、IGF-1和IGFBP-3的表达明显低于对照组,观察组中伴有骨折患者血清中瘦素、IGF-1和IGFBP-3的表达明显低于不伴有骨折患者,相关分析显示瘦素和IGF-1、IGF-1和IGFBP-3的表达均呈正相关性。结论 OP老年男性患者血清中瘦素、IGF-1和IGFBP-3低表达,瘦素和IGF-1、IGF-1和IGFBP-3均具有协同作用,三种细胞因子均参与病变形成及进展。     

胰岛素样生长因子结合蛋白3和特发性肺纤维化

特发性肺纤维化(IPF)是原因不明但发病率和病死率明显的纤维变性疾病,在肺纤维化过程中,众多细胞因子参与了细胞调控,其中胰岛素样生长因子结合蛋白3(IGFBP-3)被发现与IPF有关,但其具体作用机制还不明了.许多学者发现IGFBP-3可以通过依赖性和非依赖性地方式结合IGF,但具体的IGFBP-3信号传导通路还没完全阐明.越来越多的研究显示出IGFBP-3这种蛋白在人体多器官中的重要作用,近年来研究者们把目光聚焦在肺上,而且有关纤维化的相关研究逐渐浮出水面.但其作用机制尚不清楚,阅览国内外有关报道,可能与以下内容相关:①IGFBP-3的生长抑制和细胞凋亡作用;②IGFBP-3与IGF-1;③IGFBP-3与TGF-β1;④IGF-1与TGF-β1;⑤IGFBP-3与细胞外基质.由此可见,IGFBP-3与IPF有着潜在的必然关系,IGFBP-3在促IPF的形成扮演着重要角色.     

胰岛素样生长因子基因在非酒精性脂肪变性肝细胞模型中的表达及其意义

目的 研究胰岛素样生长因子-1 (IGF-1)及胰岛素样生长因子结合蛋白-3(IGFBP-3)基因在非酒精性脂肪变性肝细胞模型中的表达变化及其意义. 方法 用油酸诱导永生化人肝细胞(IHH)建立非酒精性脂肪性肝病(NAFLD)细胞模型,油红O染色和细胞内甘油三酯含量检测观察细胞脂肪变情况.IHH细胞分为对照组和NAFLD组,对照组细胞以DMEM/F12培养基培养,NAFLD组给予油酸0.5 mmol/L处理72 h.采用逆转录酶-聚合酶链反应及Western blot和免疫荧光染色方法检测IGF-1和IGFBP-3在两组细胞中的mRNA及蛋白质表达变化.组间均数比较采用t检验. 结果 0.5 mmol/L油酸可成功诱导IHH细胞脂肪变性,油红O染色显示细胞内脂肪滴明显增多,细胞内甘油三酯含量从对照组的(150.2±15.6)μg/ng升高到(275.7±27.2) μg/mg (t=21.67,P＜0.01).油酸诱导后,NAFLD组细胞中IGF-1和IGFBP-3的mRNA相对表达量(分.别为0.76±0.04和1.58±0.93)均较对照组(分别为4.82±1.51和5.41±1.37)明显下降,t值分别为17.915和12.893,P值均＜0.01;IGF-1和IGFBP-3的蛋白质相对表达量(分别为1.00±0.29和0.65±0.36)也较对照组(分别为2.56±0.71和1.23±0.91)明显下降,t值分别为29.17和32.12,P值均＜0.01.免疫荧光染色结果也证实NAFLD组细胞中IGF-1和IGFBP-3的蛋白质表达较对照组明显下降. 结论 非酒精性脂肪变性肝细胞模型的IGF-1和IGFBP-3表达下降,为深入研究临床上部分非酒精性脂肪肝病儿童身高受限的机制提供了实验基础.     

宫内发育迟缓与胰岛素样生长因子及其结合蛋白关系的研究

为探讨宫内发育迟缓（IUGR）的发生机制,检测了86例新生儿脐血胰岛素样生长因子－1（IGF－1）、胰岛素样生长因子结合蛋白－3（IGFBP－3）水平,并分析上述指标变化与胎儿期生长的关系。将86例新生儿分为两组,IUGR（即小于胎龄儿）组22例,适于胎龄儿（AGA）组64例,采用竞争性放射免疫分析法（RIA）测定两组脐血IGF－1水平,非竞争性免疫放射分析法（IRMA）测定IGFBP－3水平。结果显示,与AGA组相比,IUGR组脐血IGF－1和IGFBP－3水平显著降低（P＜0．001）;IGF－1水平随胎龄及出生体重增加而增加（P＜0．01）;IGFBP－3水平与胎龄及出生体重呈相关（P＜0．01）;IGF－1与IGFBP－3呈正相关（P＜0．01）。认为IUGR与IGF－1及其结合蛋白密切相关,不论何种原因引起的IUGR,其脐血IGF－1、IGFBP－3水平均低,IGF－1水平下降与IGFBP－3下降相伴随;脐血IGF－1、IGFBP－3水平与胎龄及出生体重呈正相关,随着胎龄的增加和出生体重的增长,IGF－1、IGFBP－3水平不断升高。     

非霍奇金淋巴瘤患者血清胰岛素样生长因子-1及其结合蛋白-3表达水平的初步观察

目的:探讨非霍奇金淋巴瘤(NHL)患者血清胰岛素样生长因子-1(IGF-1)及其结合蛋白-3(IGFBP-3)表达水平及其临床意义.方法:选择28例诊断初发NHL患者(淋巴瘤组)及28例健康志愿者(对照组),化学发光法测定血清IGF-1及IGFBP-3水平并计算IGF- 1/IGFBP-3值,分析组间的差异.结果:血清IGF-1及IGFBP-3水平淋巴瘤组显著低于正常对照组(均P＜0.01);IGF-1/IGFBP-3淋巴瘤组与正常对照组差异无统计学意义(P＞0.05);不同亚型的淋巴瘤组的血清IGF-1、IGFBP-3水平及IGF-1/IGFBP-3比值的差异均未达到统计学意义(P＞0.05).结论:N HL患者血清IGF-I及IGFBP-3水平明显降低,可能与NHL相关.IGF-1/IGFBP-3比值与NHL无明显相关性,IGF-1及IGFBP-3水平与NHL的分型无明显相关.     

Role of extracellular matrix in insulin-like growth factor (IGF) binding protein-2 regulation of IGF-II action in normal human osteoblasts

Insulin-like growth factor binding protein-2 (IGFBP-2) in its native form had little affinity for extracellular matrix (ECM) derived from human or rat osteoblastic cells. However, in the presence of IGFs, IGFBP-2 binding to ECM was markedly enhanced, with IGF-II being more effective than IGF-I. IGF-II-enhanced binding of IGFBP-2 to ECM was specific for IGFBP-2 of the six known IGFBPs. In the presence of IGF-II, IGFBP-2 bound with high affinity to heparin-Sepharose, but not to type I collagen, fibronectin, or laminin. Furthermore, heparin and heparan sulfate, but not chondroitin sulfate, inhibited IGFBP-2/IGF-II binding to ECM. High salt (100 mM NaCl) inhibited, while CaCl(2) enhanced binding of IGFBP-2/IGF-II to ECM. In the presence of ECM, IGFBP-2/IGF-II was as effective as IGF-II alone in stimulating [3H]thymidine and [3H]proline incorporation and in inhibiting apoptosis in cultured human osteoblasts. On the other hand, IGFBP-2 was a potent inhibitor of IGF-II action in human breast and ovarian carcinoma cells. There was no difference between soluble and ECM-associated IGFBP-2 in affinity for IGF-I and IGF-II. These data suggest a unique mechanism for targeting an anabolic IGFBP-2/IGF-II complex in bone.     

Regulation of insulin-like growth factor binding protein-1 (IGFBP-1) in insulin-dependent diabetes mellitus

The aim of the present study was to characterize the effect of 44 h of hyperglycaemia on diurnal levels of insulin-like growth factor binding protein-1 (IGFBP-1), insulin-like growth factor-1 (IGF-1), growth hormone (GH) and glucagon in 7 well-controlled subjects with insulin-dependent diabetes mellitus (IDDM). Hyperglycaemia (15 mmol/l) was induced by a glucose infusion, while the degree of insulinisation was similar to that of a corresponding period with near normoglycaemia (6.9 mmol/l). Hyperglycaemia for 44 h did not alter the normal diurnal IGFBP-1 levels when the degree of insulinisation was unchanged. The diurnal secretion pattern of IGFBP-1 was preserved in both genders and without any difference between the control and hyperglycaemic periods. However, the IGFBP-1 levels were increased in these IDDM subjects despite a peripheral hyperinsulinemia. An inverse correlation was found between IGFBP-1 and peripheral insulin levels both during periods of rapid changes in IGFBP-1 and insulin concentrations (i.e. morning hours) as well as during the total 24-h sampling period. Total IGF-1 levels were low, but no further decrease was seen after 24 h of hyperglycaemia in the presence of unchanged insulin levels. In conclusion, the present study clearly shows that the increased IGFBP-1 level seen during poor metabolic control in IDDM is not caused by hyperglycaemia. Glucose levels per se do not influence either total IGF-1 or IGFBP-1 concentrations in well-insulinised diabetic patients.     

Expression of insulin-like growth factor binding protein-2 in gastric carcinoma and its relationship with cell proliferation

INTRODUCTION The insulin-like growth factor (IGF) system plays a crucial role in normal cell proliferation and malignant transformation[1,2]. It comprises IGF-Ⅰand IGF-Ⅱ, the typeⅠand Ⅱ receptors[3], and a family of IGF binding proteins (IGFBPs) that …     

Elevated plasma insulin-like growth factor binding protein-1 levels in Type 1 (insulin-dependent) diabetic patients with peripheral neuropathy

Summary Previous studies have suggested that nerve regeneration may be defective in patients with diabetic polyneuropathy. Since insulin-like growth factor I (IGF-I) has been shown to stimulate nerve regeneration, and IGF binding protein-1 is acutely regulated by plasma insulin we have investigated the relationships between plasma IGF-I, IGFBP-1, glucose and insulin in Type 1 (insulin-dependent) diabetic patients with peripheral polyneuropathy. Plasma samples were taken at hourly intervals over an 11-h period (08.00–19.00 hours) in order to characterise secretory profiles for 15 Type 1 diabetic patients (eight neuropathic and seven non-neuropathic) and eight non-diabetic control subjects. In the non-diabetic subjects, mean plasma IGF-I levels were stable throughout the 11-h period with a range of 97 g/l–169 g/l. In contrast, mean plasma IGFBP-1 levels declined steadily from a high level of 1.99 g/l at 08.00 hours to approximately one half (0.86 g/l) at 15.00 hours. Comparison of areas under the curves revealed significant negative correlations between IGFBP-1 and glucose (–0.88, p=0.01), IGFBP-1 and insulin (–0.75, p=0.016), and IGFBP-1 and IGF-I (–0.68, p=0.03). A significant positive correlation was found between insulin and IGF-I (+ 0.89, p=0.001). The diabetic patients had markedly elevated plasma IGFBP-1 levels (area under curve, p=0.01) and lower plasma IGF-I levels (p=0.033) even though these patients were hyperinsulinaemic throughout the study period. The neuropathic diabetic patients had grossly elevated IGFBP-1 levels (–X=40 g/l at 08.00 hours) which were significantly higher (area under curve, p=0.05) than in patients without neuropathy (¯X=15 g/l at 08.00 hours). However, plasma levels of insulin and IGF-I in neuropathic and non-neuropathic subjects were similar, suggesting that the regulation of IGFBP-1 is more resistant to insulin in the neuropathic patients. In contrast to the non-diabetic subjects comparison of area under curve values revealed no positive correlation between insulin and IGF-I or negative correlations between IGF-I and IGFBP-1, and IGFBP-1 and glucose. We conclude that in Type 1 diabetes the relationships between plasma glucose, insulin, IGF-I and IGFBP-1 are clearly abnormal, and these abnormalities are more pronounced in patients with peripheral neuropathy.