Study of Mutation in Tyrosine Protein Kinase of Insulin Receptor Gene in Patients with Polycystic Ovarian Syndrome

Objective To explore the molecular mechanism of insulin resistance in the patients with polycystic ovarian syndrome (PCOS)Methods Polymerase chain reaction, silver staining-single strand conformation poly-morphism(PCR-SSCP) and DNA direct sequencing were used to detect the mutation of insulin receptor (INSR) gene in exon 17-21 with the abdominal wall adipose tissue from 31 patients with PCOS (PCOS Group) and 30 patients with pure hysteromyoma in reproductive lift (Control Group).Results Tiventy-two variant SSCP patterns in exon 17 of INSR gene were detected. Direct sequence analysis of exon 17 showed that homozygous nonsense mutation was two alleles single nucleotide polymorphism (SNP) at the codon 1058 (CAC→CAT). Exons 18-21were not detected with any significantly mutation. The INSR gene His1058C→ T substitution collecting rate and insulin resistance were significantly higher in the PCOS group than in the control group (P = 0. 0293, P<0. 05, P<0. 01). Conclusion It is suggested that the SNP in codon 1058 of the INSR gene might be related with the insulin resistance in PCOS patients, which has hereditary tendency. And the missense mutation,nonsense mutation and frameshift mutation at exons 18-21 in tyrosine protein kinase region of INSR gene for PCOS patients were not frequently observed.

1,25-Dihydroxyvitamin D_(3) effects on the regulation of the insulin receptor gene in the hind limb muscle and heart of streptozotocin-induced diabetic rats

In the present study, we examine the effects of the treatment with 1,25-dihydroxyvitamin D3 [150 IU/Kg (3.75 μg/Kg) once a day, for 15 days] to non-diabetic and streptozotocin-induced diabetic rats. The results indicate that treatment with 1,25-dihydroxyvitamin D3 had minor effects in non-diabetic rats. The same treatment in streptozotocin-induced diabetic rats, although it did not correct the hyperglycemia and hypoinsulinemia induced by the diabetes, caused other actions that could mean beneficial effects on the amelioration of diabetes e.g., it avoided body weight loss, increased calcium and phosphorus plasma levels, and corrected the over-expression of the insulin receptor mRNA species of 9.5 and 7.5 Kb present in the hind limb muscle and heart of these animals. These genomic 1,25-dihydroxyvitamin D3 effects could involve transcriptional mechanisms of repression mediated by vitamin D response elements in the rat insulin receptor gene promoter. Using computer analysis of this promoter, we propose the -249/-235 bp VDRE (5’GGGTGACCCGGGGTT3’) with a pyrimidine (T) in the (+7) position of the3’half-site as the best candidate for negative control by 1,25-dihydroxy-vitamin D3. In addition, posttranscriptional mechanisms of regulation could also be implicated. Thus, computer inspection of the5’untranslated region of the rat insulin receptor pre-mRNA indicated the presence of a virtual internal ribosome entry segment whereas the computer inspection of the3’untranslated region localized various destabilizing sequences, including various AU-rich elements. We propose that through these virtual cis-regulatory sequences, 1,25-dihydroxyvitamin D3 could control the translation and stability of insulin receptor mRNA species in the hind limb muscle and heart of diabetic rats.

The Relationship of Insulin-receptor Gene Polymorphism to Ischemic Stroke?

Objective\ To investigate the role of mutation of insulin receptor (INSR) gene in the development of ischemic stroke. Methods\ The base variations at exon 17 and 20 of INSR gene, by means of PCR SSCP were determined in 68 cases of atherothrombotic cerebral infarction (ACI), 81 cases of lacunar infarction (LI) and 62 healthy controls (HC). Results\ There were 2 alleles of T and C at exon 17 of INSR gene. The prevalence of mutant of T allele in ACI patients was more common than that in the controls. The blood pressure and the parameters of lipid metabolism in the patients with mutant were higher than those in the controls with wild type gene. However, the correlative analysis showed that the polymorphism of INSR gene was not related statistically to the blood pressure. No base variation at exon 20 was found in the study. Conclusion\ The mutation at exon 17 of INSR gene, by promoting the development of atherosclerosis, may participate in the occurrence of ischemic stroke.\;

Insulin receptor substrate gene polymorphisms are associated with metabolic syndrome but not with its components

Aim: Metabolic syndrome (MetS) is a major risk factor for both diabetes mellitus and cardiovascular disease (CVD). The aims of the study were 1) to investigate the insulin receptor substrate-1 (IRS-1) and insulin receptor substrate-2 (IRS-2) gene polymorphisms in patients with MetS and 2) to examine the relationships between gene polymorphisms and components of MetS. Patients & Methods: The study population included 100 patients with MetS and 30 patients without MetS as control group. Metabolic syndrome (MS) was defined as in ATP III. Entire coding exons of IRS-1 and IRS-2 genes were amplified by polymerase chain reaction (PCR). Insulin resistance (IR) was estimated using the homeostasis model assessment (HOMA). Results: In patients with MetS, 34 (34%), had G972R (rs1801278) gene polymorphism and 66 (66%) had no nucleotide substitutions at the IRS-1 gene (p circumference, blood pressure, triglyceride, HDL-Cholesterol, LDL-Cholesterol and HOMA-IR levels. Conclusion: Insulin receptor substrate-1 and 2 gene polymorphisms were associated with metabolic syndrome but not its components.

Resistin does not down-regulate the transcription of insulin receptor promoter

Objective: To detect the effect of resistin on the transcription of insulin receptor promoter. Methods: Luciferase reporter gene was fused downstream of human insulin receptor promoter and the enzymatic activity of luciferase was determined in the presence or absence of resistin. The resistin expressed with plasmid was stained with antibody against Myc tag which was in frame fused with resistin coding sequence, and then imaged with confocal microscopy. Results: The treatment of pIRP-LUC transfected cells with recombinant resistin did not result in significant difference in the enzymatic activity of luciferase compared to the untreated cells. Cell staining showed that green fluorescence could be observed in the cytoplasm, but not in the nucleus. Conclusion: The results suggest that the endogenous resistin may functionally locate in the cytoplasm, but does not enter the nucleus and not down-regulate the transcription of insulin receptor promoter.

Overexpression of insulin-like growth factor-Ⅰ receptor as a pertinent biomarker for hepatocytes malignant transformation

AIM:To investigate the dynamic features of insulinlike growth factor-Ⅰreceptor(IGF-ⅠR)expression in rat hepatocarcinogenesis,and the relationship between IGF-ⅠR and hepatocytes malignant transformation at mRNA or protein level.METHODS:Hepatoma models were made by inducing with 2-fluorenylacetamide(2-FAA)on male SpragueDawley rats.Morphological changes of hepatocytes were observed by pathological Hematoxylin and eosin staining,the dynamic expressions of liver and serum IGF-ⅠR were quantitatively analyzed by an enzymelinked immunosorbent assay.The distribution of hepatic IGF-ⅠR was located by immunohistochemistry.The fragments of IGF-ⅠR gene were amplified by reverse transcription-polymerase chain reaction,and confirmed by sequencing.RESULTS:Rat hepatocytes after induced by 2-FAA were changed dynamically from granule-like degeneration,precancerous to hepatoma formation with the progressing increasing of hepatic mRNA or IGF-ⅠR expression.The incidences of liver IGF-ⅠR,IGF-ⅠR mRNA,specific IGF-ⅠR concentration(ng/mg wet liver),and serum IGF-ⅠR level(ng/mL)were 0.0%,0.0%,0.63±0.17,and 1.33±0.47 in the control;50.0%,61.1%,0.65±0.2,and 1.51±0.46 in the degeneration;88.9%,100%,0.66±0.14,and 1.92±0.29 in the precancerosis;and 100%,100%,0.96±0.09,and2.43±0.57 in the cancerous group,respectively.IGF-ⅠR expression in the cancerous group was significantly higher(P<0.01)than that in any of other groups at mRNA or protein level.The closely positive IGF-ⅠR relationship was found between livers and sera(r=0.91,t=14.222,P<0.01),respectively.CONCLUSION:IGF-ⅠR expression may participate in rat hepatocarcinogenesis and its abnormality should be an early marker for hepatocytes malignant transformation.

Relationship between β3-AR Gene and Obesity, Type 2 Diabetes, Insulin Resistance in Chinese Han Population

Objective: To explore the relationship between the β3-adrenergic receptor(β3-AR)gene and obesity, T2DM. insulin resistance in Chinese Han population. Methods: Fifty-three healthy subjects, 105 subjects with simple obesity, 63 type 2 diabetic patients without obesity, and 114 type 2 diabetic patients with obesity were studied with the technique of PCR-RFLP in codon 64 of the exon region of β3-AR gene representing the variation Trp/Arg. Results:Compared with the subjects of Trp homozygous group, the individuals with Arg allele were more elevated in WHR,MBP,SBP,DBP,FBS,PBS, FINS,PINS, FCP,PCP and lower in ISI. Frequency of Arg allele was higher in HINS sub-group without T2DM. Cnclusion: The results indicate that the Trp/Arg variation might lead to insulin resistance, obesity and T2DM.β3-AR gene is supposed to be the candidate gene of insulin resistance, obesity and T2DM in ChineseHan population.

灰飞虱翅型及翅发育基因对长、短翅定向选择的响应

【目的】稻飞虱翅型调控的分子机理已较为清楚,但是在长、短翅品系不断纯化过程中翅型及翅发育基因表达水平的变化规律还不明确,因此本研究旨在阐明灰飞虱Laodelphax striatellus长、短翅品系的翅长、翅重及翅发育基因对翅型定向选择的响应,以期为明确灰飞虱翅型的遗传进化规律提供参考。【方法】在恒定条件下对灰飞虱长、短翅型分别进行14和13个连续代次的定向选择,建立长翅型和短翅型品系;测定各选择代次中两品系的长翅和短翅率、翅长和翅重;并采用qPCR方法测定翅发育基因InR1,InR2和FoxO的相对表达水平;通过比较长、短翅型品系的翅型指标和基因表达水平在各选择代次间的差异来表征翅型及翅发育基因的选择响应。【结果】长翅型和短翅型分别进行连续14和13代的定向选择,灰飞虱长翅型品系的长翅率以及短翅型品系的短翅率在各选择代次间均显著上升,均已保持在95%左右。随着选择代次的增多,长翅型品系的翅长不断增长,短翅型品系的翅长不断缩短,长、短翅型品系的翅重均呈变轻趋势。长翅型品系3龄若虫的InR1和InR2相对表达水平随选择代次的增多而下降,但FoxO相对表达水平不随选择代次变化;短翅型品系InR1,InR2和FoxO在3龄若虫中的相对表达水平随选择代次增多呈现上升趋势;这3个基因在成虫中的相对表达水平对长和短翅型的选择响应不明显。【结论】灰飞虱翅型对定向选择有明显的响应,选择翅型的比率显著上升并保持在高水平;长翅型品系经定向选择后翅变长、变薄,短翅型品系的翅则变短、变轻;多世代定向选择长翅型抑制了若虫的翅发育基因InR1和InR2的表达,而短翅型的多世代定向选择则激活了其表达,从而促进翅型纯系的形成与保持。研究结果预示灰飞虱种群能向长、短翅型纯系两个方向进化。

骨质疏松受体基因研究方向

骨质疏松症(osteoporosis)是一种以骨量低下、骨组织微结构损坏,导致骨脆性增加,易发生骨折为特征的全身性骨病。骨质疏松是多因素、多基因疾病,是遗传和环境因素交互作用的结果。笔者论述了降钙素受体基因、甲状旁腺素受体基因、雌激素受体基因、肿瘤坏死因子基因、胰岛素样生长因子1受体基因、骨保护素基因、转化生长因子基因、维生素D受体基因、Ⅰ型胶原蛋白基因的生物学特征及其与骨密度、骨质疏松、骨质疏松性骨折的关联,为骨质疏松的发病机制、预防治疗、新药开发研究提供分子生物学依据。

Molecular variation and evolution of the tyrosine kinase domains of insulin receptor IRa and IRb genes in Cyprinidae

The insulin receptor (IR) gene plays an important role in regulating cell growth,differentiation and development.In the present study,DNA sequences of insulin receptor genes,IRa and IRb,were amplified and sequenced from 37 representative species of the Cyprinidae and from five outgroup species from non-cyprinid Cypriniformes.Based on coding sequences (CDS) of tyrosine kinase regions of IRa and IRb,molecular evolution and phylogenetic relationships were analyzed to better understand the characteristics of IR gene divergence in the family Cyprinidae.IRa and IRb were clustered into one lineage in the gene tree of the IR gene family,reconstructed using the unweighted pair group method with arithmetic mean (UPGMA).IRa and IRb have evolved into distinct genes after IR gene duplication in Cyprinidae.For each gene,molecular evolution analyses showed that there was no significant difference among different groups in the reconstructed maximum parsimony (MP) tree of Cyprinidae;IRa and IRb have been subjected to similar evolutionary pressure among different lineages.Although the amino acid sequences of IRa and IRb tyrosine kinase regions were highly conserved,our analyses showed that there were clear sequence variations between the tyrosine kinase regions of IRa and IRb proteins.This indicates that IRa and IRb proteins might play different roles in the insulin signaling pathway.

胰岛素受体底物2基因突变可能与青少年起病的成人型糖尿病有关:一例报道及其遗传学分析

青少年起病的成人型糖尿病(MODY)是一类以胰岛β细胞功能障碍为特征的、有较高遗传异质性的单基因遗传糖尿病。截至2022年8月,已发现14种明确的MODY致病基因。本文报道了1例疑似MODY患者,通过外显子组测序鉴定了1个胰岛素受体底物2(IRS2)基因突变,并在患者11名家系成员中进行了验证,提出IRS2基因是一个新的MODY候选致病基因,为MODY的诊断和治疗提供更多的参考资料。

原发性高血压病胰岛素受体基因的分析

应用聚合酶链反应／单链构象多态性分析了４６例高血压患者和４９例正常血压对照者胰岛素受体基因第１７外显子的多态性，显示３种不同的ＳＳＣＰ带型，分别称为Ⅰ、Ⅱ、Ⅲ带型。其中带型Ⅰ在高血压和对照组的出现频率分别为５４．３％和３２．７％（Ｐ＝０．０５），两组间有差异；带型Ⅱ在高血压和对照组的频率分别为２６．１％和６１．３％（Ｐ＜０．０１）；带型Ⅲ两组间无差异。根据ＰＣＲ直接测序结果，带型Ⅰ的第１０４０位编码基因为ＧＡＧ而带型Ⅱ第１０４０位编码基因为ＧＡＡ，提示ＧＡＡ１０４０可能是原发性高血压病易感的基因标志。

原发性高血压家系胰岛素受体基因第17外显子变异分析

应用聚合酶链反应／单链构象多态性、PCR直接测序的方法，对6个原发性高血压家系（36人）和2个正常家系（8人）共44例受试者的胰岛素受体基因第17外显子基因变异进行了筛查，并测定了葡萄糖耐量曲线和胰岛素释放曲线以及血脂、血浆血管紧张素Ⅱ、血管紧张素原含量。结果显示，有5例受试者胰岛素受体基因第17外显子1058位编码子发生了单个碱基突变，以CAT代替了CAC但编码的组氨酸未变。该5例受试者中4例伴有高血压家族史，而且胰岛素受体基因1058位突变型轻野生型受试者空腹时血糖与胰岛素的比值低（P＜0．01），突变型的胰岛素敏感性低，而血浆血管紧张素Ⅱ水平较高（统计学处理未见显著差异，P＞0．05，可能由于突变型例数少）。因此推测，胰岛素受体基因1058位突变可能与高血压患者、有高血压遗传倾向老的胰岛素抵抗状态有关。

胰岛素受体基因多态性与缺血性脑血管病的关系

目的 探讨胰岛素受体 (IR)基因突变在缺血性脑血管病发病中的作用。方法 以 PCR-单链构像多态性 (PCR- SSCP)法对 6 8例动脉粥样硬化性血栓性脑梗死 (ACI)患者、81例腔隙性脑梗死 (L I)患者及6 2名健康对照者 (HC)检测 IR基因第 17和 2 0外显子碱基变异情况。结果 IR基因第 17外显子存在 C、T两种等位基因 ,ACI患者突变型 T等位基因频率显著高于对照者 ,且突变型患者血压及血糖、血脂代谢指标均显著高于野生型对照者 ,但相关分析显示 IR基因多态性与血压变化无关 ;第 2 0外显子未发现有碱基变异。结论 IR基因第

糖尿病人群胰岛素受体基因变异的研究

运用聚合酶链反应及单链构型多态性技术分析５２例Ⅱ型糖尿病（ＮＩＤＤＭ）者及５４例正常对照组胰岛素受体基因第１７及２０外显子的变异。结果显示：外显子１７的１００８位ＧＧＣ－ＧＧＴ多态性频率在ＮＩＤＤＭ组为２９．４％，而在正常对照组为９．０７％（χ２＝１０．０２，Ｐ＜０．００５）。外显子２０的１１６９位甘氨酸多态性ＧＧＴ→ＧＧＣ在ＮＩＤＤＭ与正常对照组的频率分别为１５．４％和３．７％（χ２＝４．３７０，Ｐ＜０．０５）。

胰岛素受体基因微卫星多态性与多囊卵巢综合征的相关性研究

目的:研究胰岛素受体基因(INSR)标志物D19S884微卫星多态性与多囊卵巢综合征(PCOS)发病的相关性,及其与PCOS患者BMI及血清生殖激素间的关系。方法:收集PCOS(155例)和非PCOS(77例)人群的血液标本,检测血清生殖激素,提取DNA并以特异引物聚合酶链反应扩增(PCR),产物经6%变性聚丙烯酰胺凝胶电泳分离,银染,检测IN-SR标志物D19S884微卫星多态性。结果:①INSR-D19S884等位基因频率分布在PCOS组和非PCOS组间无显著差异。②PCOS组,携带等位基因238患者卵泡刺激素(FSH)值显著高于其他等位基因FSH值,初潮年龄、BMI和其他血清生殖激素值在各等位基因间均无显著差异。非PCOS组,BMI及生殖激素在各基因型间均无显著差异。结论:INSR-D19S884可能不是中国汉族人群PCOS致病基因,但可能与该病进展程度存在一定相关性。

胰岛素对3T3-L1脂肪细胞中极低密度脂蛋白受体基因表达的影响

体外培养3T3-L1细胞分化模型,研究不同浓度胰岛素及慢性胰岛素刺激对3T3-L1脂肪细胞中极低密度脂蛋白受体(VLDLR)基因表达的影响.在不同浓度胰岛素及胰岛素慢性刺激的干预下,用半定量RT-PCR检测细胞VLDLRmRNA水平的变化.微量化GOD-PAP法检测培养基中残存的葡萄糖.在细胞诱导分化过程中,胰岛素浓度的增高促进VLDLR的表达;胰岛素慢性刺激下,VLDLR表达因浓度差异呈现不同变化.研究结果表明,胰岛素的浓度及慢性刺激对3T3-L1脂肪细胞的成熟和VLDLR基因的表达有显著作用,而胰岛素抵抗明显减低成熟脂肪细胞VLDLR的表达.

针刺对2型糖尿病大鼠脂肪组织INSR基因表达的影响

目的探讨针刺对2型糖尿病(type 2 diabetes mellitus,T2DM)机体脂肪组织胰岛素受体(insulinreceptor,INSR)基因表达的影响。方法给食源性肥胖大鼠腹腔注射小剂量链脲佐菌素复制T2DM模型,随机分为针刺组、优降糖组和模型组,设正常对照组。处理4周后,采用罗氏活力型血糖仪测空腹血糖(fast-ing blood sugar,FBS),采用放射免疫法检测空腹胰岛素(fastinginsulin,FINS),采用原位杂交检测脂肪细胞INSRmRNA表达,计算胰岛素敏感性指数(insulin sensitivity index,ISI)和稳态模型评估胰岛素抵抗(homeostasis model assessment of insulin resistance,Homa-IR)指数。结果与正常组比较,模型组FBS、FINS、ISI、Homa-IR水平显著上升(P<0.01),INSR基因水平表达显著降低(P<0.01);与模型组比较,治疗后优降糖组和针刺组FBS、FINS、ISI、Homa-IR显著下降(P<0.05,或P<0.01),INSR基因表达显著升高(P<0.01)。与优降糖组比较,治疗后针刺组FINS水平显著降低,INSR基因表达显著升高(P<0.01)。结论T2DM大鼠存在脂肪细胞INSR基因表达低下,针刺和优降糖均可上调T2DM大鼠脂肪细胞INSR基因表达,针刺改善T2DM大鼠脂肪细胞INSR基因表达的作用优于优降糖。

HBV前S2蛋白对胰岛素受体基因下调作用的研究

目的探讨乙型肝炎病毒前S2蛋白(pre-S2)对胰岛素受体(INSR)基因的转录调节作用。方法以pGEM-Teasy-65-2质粒为模板,扩增乙型肝炎病毒(HBV)pre-S2基因片段,构建真核表达载体pcDNA3.1-preS2,以不同剂量(1.0、1.5、2.0μg)转染肝癌细胞系HepG2和Huh7,36h及72h后分别提取转染后细胞总RNA,利用实时荧光定量PCR检测细胞内的INSR mRNA水平,观察HBV的pre-S2蛋白对INSR基因的转录调节作用,同时观察阻断pre-S2蛋白后INSR的表达情况。结果转染不同剂量pcDNA3.1-preS2后,HepG2细胞内INSR基因的表达水平分别为对照的61%、20%、11%(转染后36h)和92%、69%、37%(转染后72h),Huh7细胞内INSR基因的表达水平分别为对照的63%、47%、35%(转染后36h)和83%、73%、34%(转染后72h);细胞INSR mRNA水平随真核表达载体pcDNA3.1-preS2转染剂量的增加而降低。在转染2μgpcDNA3.1-preS2的同时,将抗pre-S2单克隆抗体加入培养上清,可部分阻断pre-S2蛋白对INSRmRNA表达的抑制,HepG2细胞中的INSRmRNA水平分别恢复到转染空质粒对照的65%(转染后36h)和81%(转染后72h),Huh7细胞中的INSRmRNA水平则分别恢复到69%(转染后36h)和96%(转染后72h)。结论HBVpre-S2蛋白对肝癌细胞系HepG2和Huh7细胞的INSR基因有明显下调作用,抗pre-S2抗体能部分阻断这种下调作用,此机制可以在分子水平部分解释肝源性糖尿病的发生。