脐带血IGF-1浓度和DNA甲基化与巨大儿发生的相关性

为探究脐带血中胰岛素样生长因子Ⅰ(insulin-like growth factor 1,IGF-1)的浓度和基因甲基化变化与巨大儿发生的关系,选择152名正常妊娠足月分娩的产妇和新生儿为对象,其中68名巨大儿,84名正常出生体重儿.收集产妇及新生儿的基本信息和脐带血样品.采用双抗体夹心ABCELISA法测定脐带血IGF-1蛋白浓度,基质辅助激光解吸附电离飞行时间质谱分析技术(MALDITOF)测定脐带血IGF-1基因启动子区CpG位点的甲基化水平.结果显示,脐带血IGF-1启动子区CpG位点均呈低甲基化状态.以所有研究对象出生体重的上四分位数(4 260 g)为拐点,出生体重4 260g组的脐带血IGF-1浓度显著高于出生体重≥4 260 g组(P=0.015),且与出生体重呈正相关关系(r=0.242,P=0.011).表明在出生体重4 260 g范围内,脐带血IGF-1浓度的增加贡献于出生体重的增长.但当胎儿过大时,存在负反馈调节机制,使脐带血IGF-1浓度降低,以限制胎儿过度增长.这些结果提示,脐带血IGF-1浓度与出生体重呈双向性关联,两者均与处于低甲基化状态的脐带血IGF-1的甲基化程度无关.     

胎盘IGF-1的表达及其DNA甲基化与IUGR的相关性分析

为探究胎盘中胰岛素样生长因子1的浓度和基因甲基化变化与宫内生长受阻(IUGR)发生的关系。选择56名正常妊娠足月分娩的产妇和新生儿为对象,其中27名IUGR患儿,29名正常出生体重儿,收集产妇及新生儿的基本信息和胎盘样本。用实时荧光定量PCR检测IGF-1 m RNA表达量,用BSP分析胎盘IGF-1基因启动子区Cp G位点的甲基化水平。IUGR组IGF-1 m RNA的ΔCT值为(7.483±1.406),对照组为(5.642±1.323),经t检验,t=3.567,p=0.001(p0.01),提示IUGR患者胎盘IGF m RNA表达低于对照组。胎盘IGF-1启动子区Cp G位点均呈高甲基化状态,两组间平均甲基化率的差异无统计学意义,但两组中男性和女性IGF-1甲基化率存在差异。IGF-1在IUGR的发生中起着重要的作用,一定水平的IGF-1对维持胎儿生长是至关重要的,其表达量的高低均与处于高甲基化状态的胎盘IGF-1的甲基化程度无关,与性别有关。     

贵州矮马IGF-I启动子-529 CpG甲基化及个别核苷酸变异与贵州矮马矮小表型有关

胰岛素样生长因子（insulin-like growth factors,IGFs）和生长（激）素（growth hormone,GH）是动物机体主要的促生长因子,它们的表达水平直接决定成熟个体的高度。贵州矮马的体高明显低于伊犁马等大型马,但其原因尚不清楚。本研究从贵州矮马基因组DNA中克隆了GH和IGF-I基因5′-侧翼序列,分别为239 bp和817 bp,包括部分启动子结构;进而采用生物信息学、比较基因组学方法对比分析了贵州矮马与伊犁马两个基因5′-侧翼序列/启动子的转录因子结合位点及潜在甲基化位点（CpG岛）分布。亚硫酸氢盐PCR测序法（bisulfite sequencing PCR,BSP）显示,两个马群的GH基因5′-侧翼区域（239 bp）内的6个CpG位点均发生了甲基化,甲基化频率无明显差异。然而,在IGF-I基因5′-侧翼区的148 bp片段内含有4个CpG位点中,贵州矮马的-529 bp处CpG位点的甲基化程度明显高于伊犁马（P < 0.01）,且该甲基化位点处于基本启动子邻近3′端;此外,两个马群IGF-I基因5′-侧翼区的-561 bp处检测到T、C碱基改变,导致贵州矮马的顺式调控元件/转录因子结合位点较伊犁马少1个,有可能影响IGF-I基因的转录效率。血清IGF-I浓度测定揭示,贵州矮马血清IGF-I含量极显著低于伊犁马（P< 0.01）。Spearman相关性结果显示,贵州矮马及伊犁马的IGF-Ⅰ基因甲基化频率与血清IGF-I浓度呈中度负相关（r=-0.468）,提示IGF-Ⅰ基因甲基化抑制其编码蛋白质的表达。结果证明,IGF-I启动子高甲基化及某些核苷酸（碱基）序列变异可能是贵州矮马个体矮小的部分原因。     

mdr1甲基化与宫颈癌新辅助化疗疗效相关性研究

目的：研究宫颈癌肿瘤细胞多药耐药基因1（mdr1）甲基化与宫颈癌新辅助化疗疗效相关性,探索适用于预测临床化疗多药耐药性的敏感指标。方法：采用MassARRYEpiTYPERDNA甲基化分析技术定量分析宫颈鳞癌（n=40）新辅助化疗前后、正常对照组（n=30）中的mdr1基因启动子区15个CpG位点的甲基化状态。结果：新辅助化疗敏感组（n=31）CpG2、3、4位点甲基化率高于行新辅助化疗耐药组（n=9）,差异有统计学意义（P〈0．05）;与新辅助化疗前组相比,化疗后组CpG_7、CpG_8、CpG_12、13、CpG_18、CpG_19、20、CpG_23、CpG_24位点甲基化率减低,差异有统计学意义（p〈0．05）;与正常组织（n=30）相比,宫颈癌（n=80）CpG_2、3、4、CpG_5、CpG6、CpG_7、CpG_8、CpG_9、10、CpG-12、13、CpG_18、CpQ_19、20、CpG_22、CpG_23、CpG_24位点甲基化率较低,差异有统计学意义（p〈0．05）。结论：宫颈癌mdr1基因甲基化水平高低与宫颈癌NACT疗效有一定相关性。     

小鼠骨髓细胞中p16和Ralb基因启动区CpG岛的甲基化位点分析

抑癌基因p16和白血病致癌因子Ralb与白血病的发生密切相关,其启动子区CpG岛的甲基化对基因表达具有重要作用.本文旨在分析p16、Ralb基因启动子区CpG岛甲基化位点信息,并比较这两个基因在小鼠骨髓细胞和原代培养的骨髓细胞中甲基化状态的差异.运用"MethPrimer"软件预测p16、Ralb基因启动子区的CpG岛,设计甲基化特异性引物.利用重亚硫酸盐测序法(BSP)检测甲基化位点信息.结果显示,p16有1个CpG岛,岛上21个CpG位点全部未发生甲基化;Ralb有2个CpG岛,CpG岛1上的5个CpG位点全部呈甲基化状态,而CpG岛2上的17个CpG位点全部呈非甲基化状态,且小鼠骨髓细胞和体外原代培养的骨髓细胞中两基因的甲基化状态一致.表明p16、Ralb基因甲基化状态未受外界培养条件的影响而改变,提示在与两基因甲基化相关的研究中体外试验可替代体内试验.     

超声多参数在预测妊娠期糖尿病巨大儿分娩方式中的临床价值

摘要 目的：探究超声多参数在预测妊娠期糖尿病巨大儿分娩方式中的应用价值。方法：选择2016年2月至2020年9月于中国人民解放军联勤保障部队第九○一医院（我院）分娩的156例妊娠期糖尿病产妇为研究对象,回顾性分析其一般临床指标及多普勒超声检测参数,按照新生儿是否为巨大儿区分为巨大儿组（52例）和非巨大儿组（104例）,对比两组胎儿超声参数差异,评估胎儿双顶径（biparietal diameter,BPD）、头围（head circumference,HC）、腹围（abdominal circumference,AC）及股骨长度（femur length,FL）与新生儿体重的相关性,纳入年龄、宫高、孕妇腹围、孕妇体重、BPD、HC、AC、FL等指标评估巨大儿单因素影响因素,最后多因素Logistic回归分析探究巨大儿独立危险因素。结果：（1）比较显示巨大儿组胎儿BPD、HC、AC和HL均大于非巨大儿组（P<0.05）;（2）Spearman相关性分析显示BPD、HC、AC和HL均与新生儿体重呈正相关（P<0.05）;（3）分析显示产妇宫高、产妇腹围、孕期增重、BPD、HC、AC和HL均为巨大儿单因素影响因素（P<0.05）;（4）Logistic多因素回归分析显示孕妇宫高、BPD、HC、AC为巨大儿独立危险因素。结论：孕期使用超声多参数对妊娠期糖尿病产妇巨大儿发生情况具有较好的预测价值,可协助医师了解胎儿相关指标,并据此选择合适的分娩方式,值得临床推广应用。     

食管癌LAPTM4B mRNA表达及其启动子区甲基化

研究溶酶体相关4次跨膜蛋白B（lysosome associated protein transmembrane 4 beta,LAPTM4B）基因在食管癌中的表达,及其启动子区甲基化状态,为进一步揭示LAPTM4B在不同肿瘤中表达高低机理提供参考.采用半定量RT-PCR法,确定42对食管癌中LAPTM4B mRNA表达.采用5对肝癌中LAPTM4B mRNA表达做内对照（利用灰度值比较）,分析该基因在食管癌中的表达强度.选取其中3对食管癌组织样品（癌组织和癌旁正常组织）,提取基因组DNA,采用亚硫酸氢钠修饰法,联合基因测序法分析LAPTM4B启动子区是否有甲基化修饰位点存在.结果发现,在42对食管癌组织中,癌组织和癌旁正常组织LAPTM4B mRNA表达存在差异：癌组织中LAPTM4B mRNA表达阳性为37/42（88.1%）,癌旁正常组织中LAPTM4B mRNA表达阳性为26/42（61.9%）.经基因测序法分析3对食管癌组织经通用引物PCR扩增的片段,发现1例癌旁正常组织样品中有3个CpG位点.以上结果表明,LAPTM4B基因与肝癌比较在食管癌中低表达,其启动子区1例癌旁正常组织在靠近转录起始点上游-418、-416和-398位置,存在3个CpG位点,而其他2例癌旁正常组织和3例癌组织中,没有发现CpG位点.这提示,LAPTM4B基因启动子区甲基化是其表达调节的重要方式.     

影响脐带血采集质量的相关性因素分析

目的回顾性分析影响脐带血采集质量的母婴因素和采集处理因素。 方法记录389份脐带血的采集量、母亲年龄、孕龄、新生儿体重、分娩方式、新生儿性别、胎次及脐带血采集至计数间隔以及采集方式。用KX-21型全自动血液分析仪进行细胞计数并计算有核细胞总数（TNC）。采用Pearson相关和Spearman秩相关进行相关性分析,采用t检验、Mann-Whitney U检验、方差分析及Kruskal-Wallis H检验进行分组比较,分析影响脐带血采集量和TNC的相关因素。? 结果脐带血采集量与TNC显著相关（r = 0.723,P < 0.001）,脐带血采集量大于80 ml时的TNC显著高于低体积者。在母婴因素中,母亲年龄与采集量及TNC差异均无统计学意义;孕龄与采集量负相关（r = -0.119,P = 0.019）,而与TNC正相关（r = 0.138,P = 0.007）,足月儿脐带血的TNC显著高于早产儿（P = 0.038）;婴儿出生体重与采集量及TNC均正相关（r = 0.236,P < 0.001;r = 0.275,P < 0.001）,体重较大婴儿脐带血的采集量和TNC均显著高于体重较小者（P?< 0.001）;剖宫产的脐带血采集量虽高于阴道分娩（P < 0.001）,但其TNC不及阴道分娩;男婴与女婴在脐带血采集量和TNC之间无显著差异。在采集处理因素中,脐带血采集至计数的时间间隔与采集量及TNC均无显著相关。 结论为提高脐带血的保存质量,应侧重选择胎儿体重较大、经阴道分娩的产妇作为脐带血供者,实验室应首先处理采集量较大的脐带血。     

脑胶质瘤组织中p16基因启动子区CpG岛甲基化检测及其临床意义研究

目的：研究脑胶质瘤中p16基因启动子区甲基化情况及其临床意义。方法：用甲基化特异性PCR技术检测42例脑胶质瘤组织和癌旁正常脑组织中p16基因启动子甲基化,并分析该基因启动子甲基化与临床病理特征之间的关系。结果：脑胶质瘤组织中p16基因异常甲基化率（38.27%）显著高于癌旁正常脑组织中p16基因的异常甲基化率（8.8%,P=0.000）。发生甲基化的肿瘤组织或者正常脑组织中p16基因mRNA和蛋白表达显著降低。此外,p16基因异常甲基化和肿瘤病理分级有相关性（P=0.007）,而与患者性别、年龄及肿瘤类型等临床特征无关（P=0.669,0.869和0.944）。结论：p16基因启动子区CpG岛高甲基化与p16表达下调相关,推测p16启动子区CpG岛高甲基化是导致p16基因在脑胶质瘤中表达下调的重要因素,有望成为脑胶质瘤早期辅助诊断的分子标志物之一。     

奶牛乳腺组织RPS6KB1基因启动子甲基化分析

DNA甲基化是目前生命科学领域的研究热点之一,DNA甲基化在维持细胞功能、遗传印记、个体生长发育中起着重要作用．本研究采用亚硫酸氢盐测序(BSP)技术检测了不同发育时期奶牛乳腺组织及不同乳品质泌乳期奶牛乳腺组织RPS6KB1启动子的甲基化特征,实时荧光定量PCR检测RPS6KB1基因mRNA差异表达．实验结果显示,在RPS6KB1基因启动子内存在CpG及非CpG的甲基化模式,其中泌乳期奶牛之间甲基化水平相似,妊娠期奶牛甲基化程度高于泌乳期奶牛．荧光定量结果显示不同发育时期,RPS6KB1基因mRNA水平表达差异显著（P<0.05）,而两组泌乳期奶牛之间差异不显著（P>0.05）.说明RPS6KB1的表达受到其启动子甲基化的调控,非CpG甲基化模式可能具有与CpG甲基化模式相似的生物学功能,参与RPS6KB1的表达调控．     

卵巢上皮癌中ING4基因启动子的甲基化状态及其临床意义

目的：探讨卵巢上皮癌中ING4基因启动子的甲基化状态及其临床意义。方法：收集2005年7月至2012年6月哈尔滨医科大学附属第一医院行全面分期手术并经病理检查确诊的150例卵巢上皮癌组织标本,并以同期因子宫肌瘤或子宫腺肌症行子宫全切除术或次全切除术并经病理检查确诊为正常卵巢组织的150例标本作为对照组。采用甲基化特异性PCR（MSP）技术检测卵巢上皮癌组织与正常卵巢组织中ING4基因启动子的甲基化状态,蛋白印迹法检测1NG4蛋白的表达,并分析ING4基因启动子的甲基化状态与卵巢上皮癌临床病例特征的关系。结果：卵巢上皮癌组织中ING4基因启动子的甲基化阳性率为42．7％（64／150）,明显高于正常卵巢组织（4％,6／150）,差异有统计学意义（P〈0．05）。ING4基因启动子甲基化阳性的卵巢上皮癌组织中ING4蛋白表达阴性或弱阳性;1NG4基因启动子甲基化阴性的卵巢上皮癌和正常卵巢组织中ING4蛋白表达阳性;在64例1NG4基因启动子甲基化的卵巢上皮癌组织中,ING4蛋白表达强度与ING4基因启动子的甲基化程度呈负相关（r=-0．435,P〈0．05）。卵巢上皮癌组织中,1NG4基因甲基化的阳性率随着手术病理分期和组织学分级的增加而增加（P〈0．05）;卵巢透明细胞癌（55．6％,10／18）和卵巢子宫内膜样癌（59-3％,16／27）中ING4基因甲基化的阳性率显著高于浆液性囊腺癌（33．9％,20／59）和粘液性囊腺癌（39．1％,18／46）（P〈0．05）;ING4基因启动子的甲基化状态与患者的年龄、有无腹水及淋巴结转移均无显著相关性（P〉0．05）。结论：ING4基因启动子的甲基化可能促进了其在卵巢上皮癌组织中的表达失活,进而促进了卵巢上皮癌的生长和分化。     

Nutrition and somatomedin. XIX. Molecular regulation of insulin-like growth factor-1 in streptozotocin-diabetic rats

Poor growth in diabetes involves low circulating levels of somatomedins/insulin-like growth factors (IGFs), largely reflecting decreased growth factor release by the liver. To define regulatory mechanisms, circulating IGF-1 was compared with levels of a high mol wt putative hepatic IGF-1 precursor and hepatic IGF-1 mRNA in a model of progressive severity of diabetes in rats. Streptozotocin administered at 36, 72, 144, and 288 mg/kg produced graded metabolic decompensation 2 days later, from minimal hyperglycemia with continued weight gain at 36 mg/kg, to marked hyperglycemia, ketonemia, and weight loss at 288 mg/kg (all P less than 0.001). Total serum IGF-1 measured by RIA was unchanged with the 36 and 72 mg/kg doses of streptozotocin (471 +/- 19 and 439 +/- 27 ng/ml, respectively, vs. 517 +/- 27 ng/ml in controls) despite serum glucose greater than 400 mg/dl. With streptozotocin 144 and 288 mg/kg, serum IGF-1 fell to 131 +/- 27 and 142 +/- 10 ng/ml, respectively (both P less than 0.005 vs. controls). Serum IGF-1 was correlated strongly with serum beta-hydroxybutyrate and body weight (r = -0.88 and 0.91, respectively, P less than 0.0001), and less strongly with serum glucose (r = -0.59, P less than 0.0002). Extractable hepatic content of a high mol wt form of immunoreactive IGF-1 (a putative precursor) was unchanged at the two lowest doses of streptozotocin (68 +/- 4 and 83 +/- 9 ngeq/g vs. 67 +/- 4 in controls), but decreased to 16 +/- 3 and 29 +/- 4 ng/g at the two highest doses (both P less than 0.001 vs. controls).(ABSTRACT TRUNCATED AT 250 WORDS)     

卵巢上皮癌中ING4 基因启动子的甲基化状态及其临床意义

目的：探讨卵巢上皮癌中ING4 基因启动子的甲基化状态及其临床意义。方法：收集2005 年7 月至2012 年6 月哈尔滨医科 大学附属第一医院行全面分期手术并经病理检查确诊的150 例卵巢上皮癌组织标本,并以同期因子宫肌瘤或子宫腺肌症行子宫 全切除术或次全切除术并经病理检查确诊为正常卵巢组织的150 例标本作为对照组。采用甲基化特异性PCR（MSP）技术检测卵 巢上皮癌组织与正常卵巢组织中ING4 基因启动子的甲基化状态,蛋白印迹法检测ING4 蛋白的表达,并分析ING4 基因启动子 的甲基化状态与卵巢上皮癌临床病例特征的关系。结果：卵巢上皮癌组织中ING4 基因启动子的甲基化阳性率为42.7%（64/150）, 明显高于正常卵巢组织（4%,6/150）,差异有统计学意义（P<0.05）。ING4 基因启动子甲基化阳性的卵巢上皮癌组织中ING4蛋白 表达阴性或弱阳性;ING4 基因启动子甲基化阴性的卵巢上皮癌和正常卵巢组织中ING4 蛋白表达阳性;在64 例ING4 基因启动 子甲基化的卵巢上皮癌组织中,ING4 蛋白表达强度与ING4 基因启动子的甲基化程度呈负相关（r=-0.435,P<0.05）。卵巢上皮癌 组织中,ING4 基因甲基化的阳性率随着手术病理分期和组织学分级的增加而增加（P<0.05）;卵巢透明细胞癌（55.6%,10/18）和卵 巢子宫内膜样癌（59.3%,16/27）中ING4 基因甲基化的阳性率显著高于浆液性囊腺癌（33.9%,20/59）和粘液性囊腺癌（39.1%, 18/46）（P<0.05）;ING4基因启动子的甲基化状态与患者的年龄、有无腹水及淋巴结转移均无显著相关性（P>0.05）。结论：ING4 基 因启动子的甲基化可能促进了其在卵巢上皮癌组织中的表达失活,进而促进了卵巢上皮癌的生长和分化。     

Gestational and hormonal regulation of human placental lipoprotein lipase

The fetal demand for FFA increases as gestation proceeds, and LPL represents one potential mechanism for increasing placental lipid transport. We examined LPL activity and protein expression in first trimester and term human placenta. The LPL activity was 3-fold higher in term (n = 7; P < 0.05) compared with first trimester (n = 6) placentas. The LPL expression appeared lower in microvillous membrane from first trimester (n = 2) compared with term (n = 2) placentas. We incubated isolated placental villous fragments with a variety of effectors [GW 1929, estradiol, insulin, cortisol, epinephrine, insulin-like growth factor-1 (IGF-1), and tumor necrosis factor-alpha] for 1, 3, and 24 h to investigate potential regulatory mechanisms. Decreased LPL activity was observed after 24 h of incubation with estradiol (1 micro g/ml), insulin, cortisol, and IGF-1 (n = 12; P < 0.05). We observed an increase in LPL activity after 3 h of incubation with estradiol (20 ng/ml) or hyperglycemic medium plus insulin (n = 7; P < 0.05). To conclude, we suggest that the gestational increase in placental LPL activity represents an important mechanism to enhance placental FFA transport in late pregnancy. Hormonal regulation of placental LPL activity by insulin, cortisol, IGF-1, and estradiol may be involved in gestational changes and in alterations in LPL activity in pregnancies complicated by altered fetal growth.     

Alteration in Expression and Methylation of IGF2/H19 in Placenta and Umbilical Cord Blood Are Associated with Macrosomia Exposed to Intrauterine Hyperglycemia

Objective

Macrosomia is one of the most common complications in gestational diabetes mellitus. Insulin-like growth factor 2 and H19 are two of the imprinted candidate genes that are involved in fetal growth and development. Change in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 has been proved to be an early event related to the programming of metabolic profile, including macrosomia and small for gestational age in offspring. Here we hypothesize that alteration in methylation at differentially methylated region of the insulin-like growth factor 2 and H19 is associated with macrosomia induced by intrauterine hyperglycemia.

Results

The expression of insulin-like growth factor 2 is significant higher in gestational diabetes mellitus group (GDM group) compared to normal glucose tolerance group (NGT group) both in umbilical cord blood and placenta, while the expression of H19 is significant lower in GDM group in umbilical cord blood. The expression of insulin-like growth factor 2 is significant higher in normal glucose tolerance with macrosomia group (NGT-M) compared to normal glucose tolerance with normal birthweight group (NGT-NBW group) both in placenta and umbilical cord blood. A model with interaction term of gene expression of IGF2 and H19 found that IGF2 and the joint action of IGF2 and H19 in placenta showed significantly relationship with GDM/NGT and GDM-NBW/NGT-NBW. A borderline significant association was seen among IGF2 and H19 in cord blood and GDM-M/NGT-M. The methylation level at different CpG sites of insulin-like growth factor 2 and H19 in umbilical cord blood was also significantly different among groups. Based on the multivariable linear regression analysis, the methylation of the insulin-like growth factor 2 / H19 is closely related to birth weight and intrauterine hyperglycemia.

Conclusions

We confirmed the existence of alteration in DNA methylation in umbilical cord blood exposed to intrauterine hyperglycemia and reported a functional role in regulating gene associated with insulin-like growth factor 2/H19. Both of these might be the underlying pathogenesis of macrosomia. We also provided the evidence of strong associations between methylation of insulin-like growth factor 2/H19 and macrosomia induced by intrauterine hyperglycemia.     

Type 2 diabetes TCF7L2 risk genotypes alter birth weight: a study of 24,053 individuals

The role of genes in normal birth-weight variation is poorly understood, and it has been suggested that the genetic component of fetal growth is small. Type 2 diabetes genes may influence birth weight through maternal genotype, by increasing maternal glycemia in pregnancy, or through fetal genotype, by altering fetal insulin secretion. We aimed to assess the role of the recently described type 2 diabetes gene TCF7L2 in birth weight. We genotyped the polymorphism rs7903146 in 15,709 individuals whose birth weight was available from six studies and in 8,344 mothers from three studies. Each fetal copy of the predisposing allele was associated with an 18-g (95% confidence interval [CI] 7-29 g) increase in birth weight (P=.001) and each maternal copy with a 30-g (95% CI 15-45 g) increase in offspring birth weight (P=2.8x10-5). Stratification by fetal genotype suggested that the association was driven by maternal genotype (31-g [95% CI 9-48 g] increase per allele; corrected P=.003). Analysis of diabetes-related traits in 10,314 nondiabetic individuals suggested the most likely mechanism is that the risk allele reduces maternal insulin secretion (disposition index reduced by ~0.15 standard deviation; P=1x10-4), which results in increased maternal glycemia in pregnancy and hence increased offspring birth weight. We combined information with the other common variant known to alter fetal growth, the -30G-->A polymorphism of glucokinase (rs1799884). The 4% of offspring born to mothers carrying three or four risk alleles were 119 g (95% CI 62-172 g) heavier than were the 32% born to mothers with none (for overall trend, P=2x10-7), comparable to the impact of maternal smoking during pregnancy. In conclusion, we have identified the first type 2 diabetes-susceptibility allele to be reproducibly associated with birth weight. Common gene variants can substantially influence normal birth-weight variation.     

High levels of glucose induce apoptosis in cardiomyocyte via epigenetic regulation of the insulin-like growth factor receptor

Diabetic hyperglycemia result in cardiovascular complications, but the mechanisms by which high levels of glucose (HG) cause diabetic cardiomyopathy are not known. We investigate whether HG-induced repression of insulin-like growth factor 1 receptor (IGF-1R) mediated by epigenetic modifications is one potential mechanism. We found that HG resulted in decreased IGF-1 receptor (IGF-1R) mRNA levels, and IGF-1R protein when compared with H9C2 rat cardiomyocyte cells incubated in normal glucose. HG also induced apoptosis of H9C2 cells. The effects of HG on reduced expression of IGF-1R and increased apoptosis were blocked by silencing p53 with small interference RNA but not by non-targeting scrambled siRNA. Moreover, HG negatively regulated IGF-1R promoter activity as determined by ChIP analysis, which was dependent on p53 since siRNA-p53 attenuated the effects of HG on IGF-1R promoter activity. HG also increased the association of p53 with histone deacetylase 1 (HDAC1), and decreased the association of acetylated histone-4 with the IGF-1R promoter. Furthermore, HDAC inhibitor relieved the repression of IGF-1R following HG state. These results suggest that HG-induced repression of IGF-1R is mediated by the association of p53 with the IGF-1R promoter, and by the subsequent enhanced recruitment of chromatin-modifying proteins, such as HDAC1, to the IGF-1R promoter-p53 complex. In conclusion, our data demonstrate that HG decreases expression of IGF-1R and decreases the association of acetylated histone-4 with the IGF-1R promoter. These studies may help delineate the complex pathways regulating diabetic cardiomyopathy, and have implications for the development of novel therapeutic strategies to prevent diabetic cardiomyopathy by epigenetic regulation of IGF-1R.     

血清Ghrelin、p21 waf/cip1以及IGF-1与儿童特发性矮小症相关性分析

摘要 目的：研究特发性矮小症（ISS）儿童血清生长激素释放肽（Ghrelin）、p21 waf/cip1以及胰岛素生长因子-1（IGF-1）水平及其临床意义。方法：选择2017年1月到2020年12月在我院接受治疗的特发性矮小症儿童60例（ISS组）,选择同期体检健康儿童60例作为对照（对照组）,比较两组儿童一般资料,检测并比较两组儿童血清Ghrelin、p21 waf/cip1以及IGF-1水平。分析ISS儿童血清Ghrelin、p21 waf/cip1以及IGF-1水平与生长指标的相关性,同时分析治疗对其影响。结果：（1）ISS组患儿性别、年龄和体质指数与对照组比较无显著差异（P>0.05）,但身高、体重以及生长速度显著低于对照组儿童（P<0.05）;（2）ISS组患儿血清Ghrelin和p21 waf/cip1均显著高于对照组,而血清IGF-1显著低于对照组（P<0.05）;（3）ISS组患儿血清Ghrelin和p21 waf/cip1均与身高、体重和生长速度呈负相关,而血清IGF-1与身高、体重和生长速度呈正相关（P<0.05）;（4）治疗显著提高ISS组患儿身高、体重、生长速度以及血清IGF-1水平,而显著降低ISS组患儿血清Ghrelin和p21 waf/cip1水平（P<0.05）。结论：Ghrelin、p21 waf/cip1和IGF-1在特发性矮小症患儿血清中表达异常,共同调控儿童生长发育,是评价儿童生长发育的良好指标。     

The effects of pancreatectomy on the plasma concentrations of insulin-like growth factors 1 and 2 in the sheep fetus

The effects of hypoinsulinaemia and altered metabolite concentrations on the fetal plasma concentrations of insulin-like growth factors (IGF) have been investigated in chronically catheterized fetal sheep made insulin deficient by pancreatic ablation. Fetal pancreatectomy reduced significantly the plasma IGF-1 concentration and increased plasma IGF-2 activity in comparison with the values observed in sham operated fetuses. Mean plasma IGF-1 concentrations in the sham operated and pancreatectomized fetuses were 18.6 +/- 3.1 ng/ml (n = 7) and 13.4 +/- 1.4 ng/ml (n = 13) respectively. When all the data were combined, there was a significant positive correlation between the plasma concentrations of IGF-1 and insulin in utero. The mean IGF-2 activity was 2349 +/- 83 ng/ml (n = 7) in the sham operated fetuses and 3800 +/- 532 ng/ml in the pancreatectomized animals (n = 13). Plasma IGF-2 activity was correlated positively with plasma glucose, fructose and alpha-amino nitrogen levels and inversely related to the plasma insulin concentration in utero. These observations demonstrate that the fetal pancreas is essential for normal IGF production in the fetus and suggest that insulin, substrate availability and the IGFs may interact in the regulation of fetal growth.     

二乙基亚硝胺诱导大鼠肝癌组织CLDN1基因表达及其甲基化

目的探讨二乙基亚硝胺（diethylnitrosamine,DEN）诱导大鼠肝癌发生中肝癌组织CLDN1基因表达及其启动子甲基化的规律。方法65只雄性Wistar大鼠随机选择40只作为模型组,其余作为正常组。模型组在1-12周饮用含DEN80mg／L的饮水以诱癌（每日8mg／kg）,各组在造模过程的第4周、8周、12周、16周随机5只取肝,第20周剩余大鼠取肝,应用RT-PCR方法检测肝组织CLDN1mRNA的表达,应用MSP法检测肝组织CLDN1启动子甲基化和非甲基化。结果模型大鼠病死率为10％（4／40）,正常组无死亡。至第20周,成瘤率达到100％。RT—PCR显示,与正常组比较,模型组在16周和20周CLDN1 mRNA表达下调（P〈0．05）,其他各周两组差异不显著。MSP结果表明,模型组肝组织CLDN1甲基化率达77．78％,而正常肝组织甲基化率为24％,两者比较差异有显著性（P〈0．01）。结论CLDN1启动子甲基化及CLDN1基因表达下调与大鼠肝癌病变相关,对其机制值得进一步深入研究。