Effect of glucocorticoid treatment on insulin like growth factor-Ⅰ and its binding proteins in children with nephrotic syndrome

Objective To identify the changes in serum insulin like growth factor Ⅰ (IGF Ⅰ) and IGF binding proteins (IGFBPs) in children with nephrotic syndrome (NS) and the effect of glucocorticoid on serum IGF Ⅰ and IGFBPs Methods We measured serum IGF Ⅰ and IGFBPs levels by radioimmune assay and immune radiomagnetic assay in 36 children with NS, consisting of an active stage group (ANS, n=12), a remission stage group (RE, n=12), an active stage group with glucocorticoid treatment (GNS, n=12), and a normal control group (NC, n=10) Results 1) Compared to NC, serum levels of IGF Ⅰ and IGFBP 3 were decreased ( P <0 01); serum levels of IGFBP 1 and IGFBP 2 were increased ( P <0 01) in the ANS group 2) Serum levels of IGF Ⅰ and IGFBP 3 were higher and IGFBP 1 and IGFBP 2 were lower in the RE Group than in theANS Group ( P <0 01) 3) Compared to the ANS group, serum levels of IGF Ⅰ and IGFBP 3 were increased ( P <0 01) and serum levels of IGFBP 1 and IGFBP 2 were decreased ( P <0 01) in the GNS group 4) A correlation was found between serum levels of IGFBP 3 and albumin in the active stage group ( r =0 76, P <0 01) There was also a correlation between serum levels of IGF Ⅰ and IGFBP 3 and an inverse correlation between the serum level of IGF Ⅰ and serum levels of IGFBP 1 and IGFBP 2 in the ANS group No other correlations were observed Conclusions The serum levels of IGF Ⅰ and IGFBPs are altered in children in the active stage of NS, but return to normal in the remission stage GC treatment may influence serum IGF Ⅰ and IGFBPs in children with NS Changes in IGF Ⅰ and IGFBPs levels may play a role in the growth retardation of NS children

Mitochondrial protection by low doses of insulin-like growth factor-Ⅰin experimental cirrhosis

AIM： To characterize the mitochondrial dysfunction in experimental cirrhosis and to study whether insulin-like growth factor-Ⅰ （IGF-Ⅰ ） therapy （4 wk） is able to induce beneficial effects on damaged mitochondria leading to cellular protection. METHODS： Wistar rats were divided into three groups： Control group, untreated cirrhotic rats and cirrhotic rats treated with IGF-Ⅰ treatment （2 μg/1O0 g bw/d）. Mitochondrial function was analyzed by flow cytometry in isolated hepatic mitochondria, caspase 3 activation was assessed by Western blot and apoptosis by TUNEL in the three expedmental groups. RESULTS： Untreated cirrhotic rats showed a mitochondrial dysfunction characterized by a significant reduction of mitochondrial membrane potential （in status 4 and 3）; an increase of intramitochondrial reactive oxigen species （ROS） generation and a significant reduction of ATPase activity. IGF-Ⅰ therapy normalized mitochondrial function by increasing the membrane potential and ATPase activity and reducing the intramitochondrial free radical production. Activity of the electron transport complexes Ⅰ and Ⅲ was increased in both cirrhotic groups. In addition, untreated cirrhotic rats showed an increase of caspase 3 activation and apoptosis. IGF- Ⅰ therapy reduced the expression of the active peptide of caspase 3 and resulted in reduced apoptosis. CONCLUSION： These results show that IGF- Ⅰ exerts a mitochondrial protection in experimental cirrhosis leading to reduced apoptosis and increased ATP production.

The effect of polymorphism in gene of insulin-like growth factor-Ⅰ on the serum periparturient concentration in Holstein dairy cows

Objective:To investigate the relationship between polymorphism within the 5'-untranslated region(5'-UTR)of IGF-I gene and its periparturient concentration in Iranian Holstein dairy cows.Methods:Blood samples(5 mL,n=37)were collected by caudal venipuncture from each animal into sample lubes containing the EDTA and DNA was extracted from blood.In order to measure ICF-I concentration the collection of blood samples(n=111)was also done at 14 d before calving(prepartum),25 and 45 d postpartum.Results:We found evidence for a significant effect of C to T mutation in position 512 of IGF-I gene on its serum concentration in dairy cows in Iran.Cows with CC genotype had significantly higher concentration(Mean-SD)of IGF-I at 14 d prepartum(91.8±18.1)μg/L compared to those with TT genotype(73.3±14.4)μg/L(P=0.04).A significant trend(quadratic)was found for IGF-I concentration,as higher in CC cows compared to ones with TT genotype,during the 14 d before calving to 45 d postpartum(P=0.01).Conclusions:We concluded that C/T transition in the promoter region of IGF-I gene can influence the serum concentration of ICF-I in periparturient dairy cows.

Effects of ethanol on insulin-like growth factor-Ⅰ system in primary cultured rat hepatocytes: Implications of JNK1/2 and alcoholdehydrogenase

AIM: To evaluate the effects of ethanol on the insulin- like growth factor-Ⅰ (IGF-Ⅰ) system involved in c-Jun N-terminal kinase (JNK1/2) and alcoholdehydrogenase (ADH) activity in primary cultured rat hepatocytes. METHODS: Hepatocytes isolated from male Sprague-Dawley rats were incubated with various concentrations of ethanol for different durations of time. The cells were pretreated with SP600125 (10 μmol/L) and 4-MP (200 μmol/L), and then treated with ethanol (200 mmol/L). We then measured IGF-Ⅰ secretion, IGF-Ⅰ mRNA expression, cell viability and JNK1/2 activity by radioimmunoassay, RT-PCR, MTT assay and Western blot, respectively (n = 6). RESULTS: Ethanol induced the activity of phospho (p)-JNK1/2, reaching a maximum at 60 min and then decreasing at 180 min. The effects of ethanol on the IGF-Ⅰ system were increased at 60 min (secretion: 7.11 ± 0.59 ng/mg protein vs 4.91 ± 0.51 ng/mg, mRNA expression: 150.2% ± 10.2% vs 101.5% ± 11.3%, P = 0.045) and then decreased at 180 min (secretion: 3.89 ± 0.25 ng/mg vs 5.4 ± 0.54 ng/mg protein; mRNA expression: 41.5% ± 10.4% vs 84.7% ± 12.1%, P = 0.04), however cell viability was decreased in a dose- and time-dependent manner. SP600125 blocked the ethanol-induced changes (at 60 min). Additionally, 4-methylpyrazole prevented the ethanol-induced decreases in the IGF-Ⅰ system, cell viability and p-JNK1/2 activity (at 180 min). CONCLUSION: This study suggests that ethanol- induced p-JNK1/2 activation is associated with the IGF-Ⅰ system and cell viability in hepatocytes. Furthermore, alcohol dehydrogenase is involved in the relationship between ethanol-induced inactivation of p-JNK1/2 and the changes of the IGF-Ⅰ system and cell viability.

Reactivation of the insulin-like growth factor-Ⅱsignaling pathway in human hepatocellular carcinoma

Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma(HCC).Especially the over- expression of the fetal growth factor IGF-Ⅱ,IGF-Ⅰ receptor(IGF-IR),and cytoplasmic downstream effectors such as insulin-receptor substrates(IRS)contribute to proliferation,anti-apoptosis,and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-Ⅱsignaling during HCC development and progression.Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies,various experimental strategies have been developed,including neutralizing antibodies and selective receptor kinase inhibitors,with respect to the specific and efficient reduction of oncogenic IGF-Ⅱ/IGF-IR-signaling.

Improvement in erectile dysfunction after insulin-like growth factor-1 gene therapy in diabetic rats

Aim： To determine whether adenoviral gene transfer of insulin like growth factor-1 （IGF-1） to the penis of streptozotocin （STZ）-induced diabetic rats could improve erectile capacity. Methods： The STZ diabetic rats were transfected with AdCMV-βgal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction （RT-PCR）, Western blot and histology. The penis β-galactosidase activity and localization of the STZ diabetic rats were also determined. Results： One to two days after transfection, the β-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-βgal. One to 2 days after administration of AdCMV- IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure （ICP/MAP） and total intracavernous pressure （ICP）, was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology. Conclusion： Gene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF- 1 might be a new therapeutic intervention for the treatment of erectile dysfunction （ED） in the STZ diabetic rats.

Insulin like growth factor-1 increases fatty liver preservation in IGL-1 solution

AIM: To investigate the benefits of insulin like growth factor-1 (IGF-1) supplementation to serum-free institut georges lopez-1 (IGL-1) solution to protect fatty liver against cold ischemia reperfusion injury. METHODS: Steatotic livers were preserved for 24 h in IGL-1  solution supplemented with or without IGF-1 and then perfused "ex vivo " for 2 h at 37℃. We examined the effects of IGF-1 on hepatic damage and function (transaminases, percentage of sulfobromophthalein clearance in bile and vascular resistance). We also studied other factors associated with the poor tolerance of fatty livers to cold ischemia reperfusion injury such as mitochondrial damage, oxidative stress, nitric oxide, tumor necrosis factor-α (TNF-α) and mitogen-activated protein kinases.RESULTS: Steatotic livers preserved in IGL-1 solutionsupplemented with IGF-1 showed lower transaminase levels, increased bile clearance and a reduction in vascular resistance when compared to those preserved in IGL-1solution alone. These benefits are mediated by activation of AKT and constitutive endothelial nitric oxide synthase (eNOS), as well as the inhibition of inflammatory cytokines such as TNF-α. Mitochondrial damage and oxidative stress were also prevented.CONCLUSION: IGL-1  enrichment with IGF-1 increasedfatty liver graft preservation through AKT and eNOS activation, and prevented TNF-α release during normothermic reperfusion.

Relationship between Insuline-like Growth Factor-I and Progesterone Secretion of Cultured Human Trophoblast Cells in Vitro

Objective To investigate the effect of insuline-like growth factor-Ⅰ （IGF-Ⅰ） on progesterone genesis and regulation. Methods Cytotrophoblast cells were collected by trypsin-collagenase digestion and percoll gradient centrifugation for primary culture. After stimulated with different concentrations（100 μg/ml, 10 μg/ml, 1 μg/ml, 0.1 μg/ml） of IGF-Ⅰ at the same time and with different duration（12 h,24 h,48 h, 72 h） of IGF-Ⅰ with the same concentration, progesterone levels in the media were measured by radioimmunoassay. Simultaneously, semiquantitative reverse transcriptase polymerase chain reaction （RT-PCR） was applied to determine the expression of low density lipoprotein receptor （LDLR） mRNA. Results Progesterone levels correlated positively with IGF-Ⅰ along with the IGF-Ⅰ concentration increasing, progesterone level began to increase at 12 h, and reached the climax at 48 h when cultured with 100 μg/L IGF-Ⅰ. The expression of LDLR mRNA was detectable in every group and accordant with variation of progesterone level. Conclusion Progesterone secretion has time- and dose-dependent effect on IGF-Ⅰ, and IGF-1 can up-regulate the expression of LDLR mRNA. IGF-Ⅰ may play an important role in promoting secretion of progesterone in trophoblast cells.

饥饿和再投喂期间尼罗罗非鱼生长、血清生化指标和肝胰脏生长激素、类胰岛素生长因子-Ⅰ和胰岛素mRNA表达丰度的变化

在室内可控条件下,对尼罗罗非鱼[初始体质量（62.50±3.44）g]进行饥饿28d和随后再投喂21d的处理,于饥饿第0、7、14、21、28天和再投喂第14、21天进行采样分析,研究饥饿和再投喂期间尼罗罗非鱼生长、血清生化指标和肝胰脏生长激素（GH）、类胰岛素生长因子-Ⅰ（IGF-Ⅰ）和胰岛素（IN）mRNA表达丰度的变化。结果显示,与饥饿第0天相比,饥饿超过7d鱼体体质量显著降低（P〈0.05）,再投喂21d显著增加（P〈0.05）;肝体比随饥饿时间延长显著降低（P〈0.05）,恢复投喂后较饥饿时升高,但显著低于饥饿前水平（P〈0.05）。在血清指标上,甘油三酯、血糖、碱性磷酸酶、谷草转氨酶和谷丙转氨酶均随饥饿时间延长而逐渐降低,恢复投喂后均有不同程度提高,但转氨酶活性显著低于饥饿前水平（P〈0.05）;饥饿和再投喂对血清总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇无显著影响（P〉0.05）。在激素方面,与饥饿第0天相比,饥饿使血清GH含量及其肝胰脏mRNA表达丰度显著升高,血清IGF-Ⅰ及其肝胰脏mRNA表达丰度降低,恢复投喂后两者均显著升高（P〈0.05）;INmRNA表达丰度在饥饿7~21d显著升高（P〈0.05）,饥饿第28天时无显著差异（P〉0.05）,再投喂后显著降低（P〈0.05）。

胰岛素样生长因子-Ⅰ促进体外组织工程软骨形成

目的 探讨胰岛素样生长因子 - (IGF- )体外促进以透明质酸 (HA)为支架材料的组织工程软骨形成的能力。 方法 分离培养人关节软骨细胞 ,分为 3组 :1IGF- 组 :HA支架材料 +软骨细胞 +IGF- ;2细胞组 :HA支架材料 +软骨细胞 ;3对照组 :单纯 HA支架材料。各组在 DMEM中培养 ,3、6周停止培养 ,取组织块通过 HE染色判断培养组织的形态 ,采用甲苯胺蓝染色、 型胶原免疫组织化学及 、 型胶原 RT- PCR判断体外组织形成软骨的能力。 结果 IGF- 组和细胞组在第 6周均能形成典型的软骨组织陷窝 ,细胞组的陷窝数量明显低于 IGF- 组 ;对照组不能形成软骨组织。 型胶原免疫组织化学示 IGF- 组阳性表达强于细胞组 ;RT- PCR示 IGF- 组的 型前胶原量明显高于细胞组 (P<0 .0 5 ) ,而 型前胶原的表达量明显低于细胞组 (P<0 .0 5 ) ,差异具有统计学意义。 结论 IGF- 能促进体外构建的组织工程软骨形成 ,并提高其质量。

寿光鸡IGF-Ⅰ基因多态性与体重及屠体性状关系的研究

采用PCRRFLP技术,对200只寿光鸡的胰岛素样生长因子Ⅰ(IGFⅠ)基因的5′端调控区进行遗传多态性研究,该调控区的扩增产物经PstⅠ酶切后出现AA、AB和BB3种基因型,其基因型频率分别是0.335、0.485和0.180。经χ2检验,寿光鸡在IGFⅠ位点上处于HardyWeinberg平衡状态(P>0.05)。分析基因型与10周龄体重和部分屠体性状时发现:基因型对半净膛重和胸肌重有显著影响(P<0.05)。公鸡中在半净膛重和胸肌重上基因型BB与AB、AA之间存在显著差异(P<0.05),而母鸡群体中却在肝脏重和半净膛重上基因型BB同AB、AA之间存在显著差异(P<0.05)。在研究指标中寿光鸡的BB基因型效应均大于AB和AA基因型。

肝癌和癌旁肝组织中IGF-Ⅰ,IGF-Ⅰ受体mRNA的表达

目的 探讨胰岛素样生长因子Ⅰ（ＩＧＦⅠ） 及其受体（ＩＧＦⅠＲ）在肝细胞癌变过程中的作用及意义．方法 采用ＤＮＡＲＮＡ 原位杂交方法观察肝癌（ ｎ ＝ ３０） 和癌旁肝组织中ＩＧＦⅠ，ＩＧＦⅠ受体ｍ ＲＮＡ 的表达．结果 在肝癌和癌旁肝组织中ＩＧＦⅠ的表达率分别为４０－０ ％和５０－０ ％ ，ＩＧＦⅠ受体的表达率分别为４６－７ ％ 和５３－３ ％ ；ＩＧＦⅠ，ＩＧＦⅠ受体在分化较差的癌细胞和不典型增生肝细胞中表达最为明显．结论 ＩＧＦⅠ和ＩＧＦⅠ受体可能在肝细胞癌变过程中发挥重要作用．

脐血瘦素、胰岛素样生长因子-Ⅰ与胎儿生长发育

目的揭示脐血瘦素及胰岛素样生长因子-Ⅰ(IGF-Ⅰ)与胎儿生长发育的关系,探讨其在胎儿生长发育方面的相互作用及临床意义。方法采用放射免疫法测定86例新生儿脐血瘦素、IGF-Ⅰ水平,根据胎龄及出生体重百分位数的关系分为:小于胎龄儿(SGA)组16例、适于胎龄儿(AGA)组41例及大于胎龄儿(LGA)组29例。同时测量新生儿的出生体重、身长、头围、足长、胎盘重量并计算体质指数(BMI)。结果①脐血瘦素水平SGA组与AGA组间差异有统计学意义(P<0.05);脐血IGF-Ⅰ水平AGA与LGA组间差异有统计学意义(P<0.05)。②脐血瘦素及IGF-Ⅰ水平分别与新生儿出生体重、身长、头围、足长、BMI及胎盘重量呈显著正相关(P<0.01),脐血瘦素与IGF-Ⅰ水平亦呈显著正相关(P<0.01)。③脐血瘦素水平与新生儿性别及分娩方式间差异均无统计学意义(P>0.05);脐血IGF-Ⅰ水平与新生儿性别差异无统计学意义(P>0.05),与新生儿分娩方式差异有统计学意义(P<0.05)。结论脐血瘦素、IGF-Ⅰ在调节胎儿生长发育方面起着重要作用,参与胎儿的生长发育过程,可作为评价胎儿生长发育及营养状态的临床指标之一。脐血瘦素、IGF-Ⅰ水平异常可能是引起胎儿宫内生长迟缓和巨大儿发生的原因之一。

丹参对兔骨性关节炎关节软骨白介素-1β、白介素-6和胰岛素样生长因子-Ⅰ表达的影响

目的:探讨丹参对兔骨性关节炎(OA)模型关节软骨退变的保护作用及其机制。方法:将24只大白兔随机分成2组,即对照组和实验组,每组12只。所有兔通过手术建立右膝关节OA动物模型,对照组的所有兔的右膝关节腔内注射生理盐水0.5ml/kg,实验组所有兔的右膝关节腔内注射丹参注射液0.5ml/kg,手术完毕后当天就注射1次,以后每4天注射1次。在动物OA模型建立后的第10周,将兔处死,收集右侧股骨内侧髁标本,用光学显微镜和透射式电子显微镜观察关节软骨形态学结构改变,用免疫组化技术检测关节软骨组织中IL-1β、IL-6和IGF-Ⅰ蛋白的表达。结果:实验组兔的关节软骨破坏程度明显轻于对照组(P<0.05)。IL-1β、IL-6和IGF-Ⅰ蛋白阳性免疫反应物主要定位于细胞浆,为粗细较为一致的淡红色颗粒。实验组IL-1β蛋白阳性染色强度明显低于对照组(P<0.05)。实验组IL-6和IGF-Ⅰ蛋白阳性染色强度明显高于对照组(P<0.05)。结论:丹参能调节OA关节软骨组织中IL-1β、IL-6和IGF-Ⅰ蛋白的异常表达,对关节软骨具有保护作用。

半胱胺盐酸盐和LHRH-A对黄鳍鲷IGF-Ⅰ基因表达和生长的影响

本文以黄鳍鲷 (Sparuslatus)为研究对象 ,利用GeneRaceTM 技术 ,从其肝组织中克隆出类胰岛素生长因子 (IGF Ⅰ )cDNA ,并应用半定量RT PCR方法研究了半胱胺盐酸盐 (Cysteaminehydrochloride)和LHRH A对其肝组织IGF Ⅰ基因表达的影响。黄鳍鲷IGF ⅠcDNA全长为 84 0bp ,编码 185aa多肽 ;序列分析表明 ,黄鳍鲷IGF Ⅰ基因编码的氨基酸序列与金鱼的同源性为 75 8% ,与牙鲆的同源性为 86 5 % ,与同属鲷科的黑鲷同源性高达 10 0 % ,证明鱼类类胰岛素生长因子是非常保守的 ,E区域分析结果表明黄鳍鲷IGF Ⅰ属Ea 4型。在饲料中投喂CSH、LHRH A等添加剂 ,实验组黄鳍鲷鱼种的相对生长率、垂体GH含量、肝脏IGF ⅠmRNA水平均显著高于对照组。以上结果提示 :CSH、LHRH A能促进黄鳍鲷生长激素的合成和IGF Ⅰ基因的表达 。

谷胱甘肽对育肥羊生长性能及生长激素/胰岛素样生长因子-Ⅰ轴调控作用的研究

本文旨在研究谷胱甘肽(glutathione,GSH)对育肥羊生长性能及生长激素/胰岛素样生长因子-Ⅰ(GH/IGF-Ⅰ)轴的影响。试验采用单因素随机区组设计,将12只3月龄东北细毛羊与德国肉用美利奴羊杂交一代育肥羊分为3组,每组4个重复,每组羊公母各占1/2。对照组饲喂基础日粮,试验组1和试验组2分别在基础日粮的基础上添加500和800 mg/kg的GSH,试验期为60 d。测定谷胱甘肽对育肥羊生长性能和血清中GH和IGF-Ⅰ浓度及组织中IGF-Ⅰ mRNA表达量的影响。结果表明:日粮中添加GSH显著提高了试验组育肥羊的日增重(P<0.05),显著降低了试验组育肥羊的料重比(P<0.05),但对育肥羊的日采食量无显著影响(P>0.05);试验20、40和60 d时,试验组育肥羊血清中的生长激素(GH)和胰岛素样生长因子-Ⅰ(IGF-Ⅰ)水平显著高于对照组(P<0.05);与对照组相比,试验组育肥羊肝脏和背最长肌中IGF-Ⅰ mRNA的表达量有所提高,当GSH添加量达到800 mg/kg时,育肥羊背最长肌中IGF-Ⅰ mRNA的表达量显著高于对照组(P<0.05)。因此,本试验初步得出,日粮中添加GSH促进了肝脏IGF-Ⅰ的分泌,提高了肌肉中IGF-Ⅰ mRNA的表达量,提高血清中GH与IGF-Ⅰ浓度,从而促进了育肥羊的生长。

表皮生长因子和胰岛素样生长因子-Ⅰ对21日龄断奶仔猪胃和小肠发育的作用

选用21日龄断奶长白仔猪3窝(37头),随机分为表皮生长因子、胰岛素样生长因子-Ⅰ、基础日粮、自然哺乳4组,探讨17.86μg d/剂量下的表皮生长因子和胰岛素样生长因子-Ⅰ对21日龄断奶长白仔猪胃和小肠发育的作用。采用H E染色、比色、原位杂交和Western Blot等方法,分别检测了小肠黏膜形态;小肠重量、DNA和RNA含量;胃肠消化酶和小肠双糖酶活性;小肠表皮生长因子受体和胰岛素样生长因子-Ⅰ受体表达;小肠黏膜H SP70蛋白表达。本试验结果表明,该剂量表皮生长因子和胰岛素样生长因子-Ⅰ可促进21日龄断奶长白仔猪小肠黏膜形态的发育,激活胃和小肠消化酶和双糖酶,与其相应的受体结合,改善断奶应激。表皮生长因子和胰岛素样生长因子-Ⅰ具有促进早期断奶仔猪胃和小肠发育的作用。

鸡类胰岛素生长因子Ⅰ的克隆、表达及其表达产物的生物学活性研究

应用RT-PCR方法对雏鸡肝脏总RNA中鸡类胰岛素生长因子Ⅰ基因cDNA进行扩增,然后将特异性片段连接到pMD18-T载体,测序结果表明,与已知序列同源性为100%。然后将特异性片段连在pRLC载体上进行表达,经Tricine-SDS-PAGE分析,原核表达产物为7.6kD的重组蛋白,占菌体总蛋白的23%,Western印迹表明重组蛋白具有IGF-Ⅰ抗原活性。表达产物以包涵体形式存在,经7mol·L-1盐酸胍的变性液溶解及0.5mol·L-1精氨酸复性液处理,表达产物随后进行脱盐、凝胶层析纯化、MTT法分析其对NIH3T3和鸡胚成骨细胞的增殖效应,结果表明重组鸡IGF-Ⅰ具有较高的生物学活性。

生长激素和胰岛素样生长因子Ⅰ对奶牛乳蛋白合成关键激酶及调节因子mRNA表达量的影响

本试验旨在探讨生长激素(GH)和胰岛素样生长因子Ⅰ(IGF-Ⅰ)对体外培养的奶牛乳腺上皮细胞内调控乳蛋白合成的关键激酶及调节因子mRNA表达量的影响。试验对纯化后的荷斯坦奶牛乳腺上皮细胞进行4种处理,对照组采用无血清生长培养基,试验组在对照组的基础上分别添加GH(100 ng/mL)、IGF-Ⅰ(100 ng/mL)和GH(100 ng/mL)+IGF-Ⅰ(100 ng/mL)。培养24 h后,采用实时定量PCR(RT-qPCR)法测定κ-酪蛋白基因以及调控乳蛋白合成的关键激酶及调节因子的mRNA表达量,并测定生长激素受体(GHR)和胰岛素样生长因子Ⅰ受体(IGF-ⅠR)mRNA表达量。结果表明:体外培养的奶牛乳腺上皮细胞可以表达GHR和IGF-ⅠRmRNA,各试验组均能显著提高κ-酪蛋白(CSN3)mRNA表达量(P<0.05),但未发现GH和IGF-Ⅰ复合存在累积效应;与对照组相比,GH组有提高E74-样转录因子5(ELF5)mRNA表达量的趋势(P<0.10),而IGF-Ⅰ组显著提高了哺乳动物雷帕霉素靶蛋白(mTOR)和核糖体蛋白S6激酶1(rpS6K1)mRNA表达量(P<0.05),GH+IGF-Ⅰ组未呈现加强作用。结果提示,GH和IGF-Ⅰ可能单独通过影响调控乳蛋白合成的关键激酶及调节因子mRNA表达来调节κ-酪蛋白的合成。

脂联素、瘦素及胰岛素样生长因子-Ⅰ在胎儿生长发育中的作用

目的探讨脂联素、瘦素及胰岛素样生长因子-Ⅰ（IGF—Ⅰ）在胎儿生长发育中的作用。方法选择2006年10月-2007年10月在本院产科出生的新生儿86例。胎龄31—42周；男57例，女29例。根据不同出生体质量分为小于胎龄儿（SGA）组（16例），适于胎龄儿（AGA）组（41例）及大于胎龄儿（LGA）组（29例）。胎儿娩出后立即断脐留脐血20mL，采用放射免疫分析法测定血清脂联素、瘦素及IGF—Ⅰ水平，同时检测其血脂水平，测量新生儿生长参数，计算体质量指数（BMI）。结果1．新生儿脐血瘦素、脂联素及IGF—Ⅰ水平无显著性别差异。2．脐血瘦素水平在SGA、AGA、LGA3组间有显著差异（P〈0．001），LGA组显著高于AGA及SAG组（P〈10．01，0．001）；脐血瘦素水平与体质量、胎龄、头围、身长、足长及胎盘质量均呈显著正相关（Pa〈0．01）。3．脐血脂联素水平与出生体质量、头围、足长、BMI水平均呈显著正相关（Pa〈0．05）。脐血脂联素水平在SGA、AGA、LGA3组间有显著差异（P〈0．001），LGA组高于AGA及SAG组（Pa〈0．01）。4．LGA组脐血IGF—Ⅰ水平显著高于AGA及SAG组，3组间有明显差异（P〈0．001）；脐血IGF—Ⅰ水平与体质量、头围、身长、足长及胎盘质量均呈显著正相关（Pa〈0．01）。5．脐血瘦素与脂联素、IGF—Ⅰ水平呈显著正相关（Pa〈0．01），脐血脂联素与IGF—Ⅰ水平无明显相关关系（P〉0．05）。6．SGA、AGA、LGA3组血脂水平比较无显著差异（Pa〉0．05）。脐血IGF—Ⅰ水平与三酰甘油水平呈明显负相关（P〈0．05），脐血脂联素、瘦素水平与血脂各指标间均无明显相关性（Pa〉0．05）。结论瘦素与脂联素、IGF-Ⅰ在胎儿宫内生长和发育过程中起重要的调节作用，可作为评价胎儿生长发育及营养状态的临床指标之一。