Association between Polymorphisms of Insulin and Insulin Receptor Gene with Childhood Obesity in Malay Population / Jurnal Sains Kesihatan Malaysia

Childhood obesity is a global epidemic, which leads to the increasing number of studies on genetic locations associated with obesity-related traits. Polymorphisms of insulin (INS) gene have been shown to be associated with obesity-related phenotypes in Europeans; while insulin receptor (INSR) gene has been associated with energy regulation. Therefore, this study was conducted to investigate the association between the INS (rs689) and INSR (rs3745551) gene polymorphisms with childhood obesity risk in a Malay childhood population. Normal weight (538) and overweight or obese (557) children aged 6-12 years old were genotyped using semi-automated Sequenom iPLEX® Gold. Body mass index (BMI) was calculated from measured body weight and height. The rs689 (T/T: 0.006, A/T: 0.159 and A/A: 0.835) and rs3745551 (G/G: 0.054, A/G: 0.378 and A/A: 0.568) genotype distributions were consistent with Hardy Weinberg equilibrium. The T-minor allele frequency for rs689 was 8.6% and G-minor allele frequency for rs3745551 was 24.3%. Minor allele of INS gene polymorphisms significantly increased risk of obesity among Malay children (sex- and age-adjusted OR=1.580; 95%CI: 1.134-2.201). However, INSR gene polymorphisms were not significantly associated with childhood obesity. In conclusion, the polymorphisms of INS gene, rather than INSR gene, were associated with childhood obesity in the Malay population.

Effect of AngⅡ on Insulin Gene Expression in RIN-m Cells and Its Molecular Mechanism / 中国药师

Objective:To discuss the effect of AngⅡ on insulin gene expression IN RIN-m cells and its molecular mechanism. Methods:RIN-m cells were cultured and divided into three groups, including the control group, 100 nmol·L-1 AngⅡ group and losartan pretreatment group. After 24-hour incubation, insulin gene expression in RIN-m cells was detected by RT-PCR, the mean flu-orescent intensity of 2', 7'-dichlorofluorescein ( DCF) was detected by flow cytometry, PDX-1 and MafA mRNA expression were detec-ted by RT-PCR and the protein expression was detected by Western-blot. Results: Insulin expression in RIN-m cells, cellular ROS level, PDX-1 expression and MafA expression in 100 nmol · L-1 AngⅡ group were significantly different from those in the control group and losartan pretreatment group (P0. 05). Conclusion:AngⅡ can down-regulate PDX-1 and MafA expression inβ-cells through oxidative stress pathway, and then inhibit insu-lin gene expression. Pretreatment with losartan can antagonize the effect of AngⅡ, and has protective effect onβ-cells in the aspect of insulin gene expression.

Insulin-like growth factor 1 gene (CA)n repeats and a variable number of tandem repeats of the insulin gene in Brazilian children born small for gestational age

OBJECTIVE: To investigate the influence of (CA)n repeats in the insulin-like growth factor 1 gene and a variable number of tandem repeats of the insulin gene on birth size in children who are small or adequate-sized for gestational age and to correlate these polymorphisms with serum insulin-like growth factor 1 levels and insulin sensitivity in children who are small for gestational age, with and without catch-up growth. PATIENTS AND METHODS: We evaluated 439 infants: 297 that were adequate-sized for gestational age and 142 that were small for gestational age (66 with and 76 without catch-up). The number of (CA)n repeat in the insulin-like growth factor 1 gene and a variable number of tandem repeats in the insulin gene were analyzed using GENESCAN software and polymerase chain reaction followed by enzymatic digestion, respectively. Clinical and laboratory data were obtained from all patients. RESULTS: The height, body mass index, paternal height, target height and insulin-like growth factor 1 serum levels were higher in children who were small for gestational age with catch-up. There was no difference in the allelic and genotypic distributions of both polymorphisms between the adequate-sized and small infants or among small infants with and without catch-up. Similarly, the polymorphisms were not associated with clinical or laboratory variables. CONCLUSION: Polymorphisms of the (CA)n repeats of the insulin-like growth factor 1 gene and a variable number of tandem repeats of the insulin gene, separately or in combination, did not influence pre- or postnatal growth, insulin-like growth factor 1 serum levels or insulin resistance. .

Effect of ISL1 over-expression on proliferation of HIT-T15 cells / 中华内分泌代谢杂志

The effect of insulin gene enhancer binding protein (ISL1) on proliferation of HIT-T15 cells was investigated.ISL1 significantly promoted cell proliferation.ISL1 also increased the advance of HIT-T15 cell phase significantly.The results showed that ISL1 promoted proliferation of HIT-T15 cells.

Type 1 diabetes susceptibility determined by HLA alleles and CTLA-4 and insulin genes polymorphisms in Brazilians / Suscetibilidade ao diabetes tipo 1 determinada por alelos de HLA e polimorfismos nos genes CTLA-4 e insulina em brasileiros

INTRODUCTION:Type 1A diabetes mellitus (T1ADM) is a multifactorial disease in which genetic and environmental aspects are important to its development. The association of genetic variations with disease has been demonstrated in several studies; however, the role of some gene loci has not yet been fully elucidated. OBJECTIVE:To compare the frequency of HLA alleles and polymorphism in CTLA-4 and insulin genes in Brazilians with T1ADM and individuals without the disease, as well as to identify genetic markers that are able to discriminate between diabetic and non-diabetic individuals. METHODS: The presence of HLA DQB1, DQA1 and DRB1 alleles, as well as the -2221 MspI polymorphism in the insulin gene and 49 A/G in the CTLA-4 gene were identified by the "Time-resolved fluorometer" technique after hybridization with probes labeled with Eu (III) / Sm (III) and Tb (III). RESULTS: The DQB1 *0302 and DQA1 *03 alleles were identified as predisposed to T1ADM, and the DQB1 *0301 allele presented a protective effect against the disease.The DQA1 label proved to be able to differentiate between 71.13 percent of the diabetic and non-diabetic individuals.This value increased to 82.47 percent when the DQB1 label was added. No significant difference in the frequency of polymorphisms in the insulin and CTLA-4 genes was observed between the two groups. CONCLUSIONS: The genetic markers that best characterized and discriminated diabetic and non-diabetic individuals were the HLA DQA1 and DQB1.alleles.

INTRODUÇÃO: O diabetes melito tipo 1 (T1ADM) é uma doença multifatorial em que os aspectos genéticos e ambientais são importantes para o seu desenvolvimento. A associação das variações genéticas com a doença tem sido demonstrada em vários trabalhos, no entanto, o papel de alguns locos gênicos não foi ainda completamente elucidado. OBJETIVOS: Comparar a frequência de alelos do HLA e polimorfismos nos genes CTLA-4 e insulina em brasileiros com T1ADM e indivíduos sem a doença, além de identificar marcadores gênicos que sejam capazes de discriminar indivíduos diabéticos e não diabéticos. MÉTODOS: A presença dos alelos de HLA DQB1, DQA1 e DRB1, bem como dos polimorfismos -2221 MspI no gene da insulina e 49 A/G no gene CTLA-4, foram identificados por meio da técnica Time-resolved fluorometer, após hibridização com sondas marcadas com Eu (III)/Sm (III) e Tb (III). RESULTADOS: Os alelos DQB1*0302 e DQA1*03 foram identificados como sendo de predisposição ao T1ADM, e o alelo DQB1*0301 mostrou um efeito protetor à doença. Analisando somente o marcador DQA1, este mostrou ser capaz de diferenciar 71,13 por cento dos indivíduos entre diabéticos e não diabéticos, cujo valor aumentou para 82,47 por cento quando adicionado o marcador DQB1. A frequência dos polimorfismos nos genes da insulina e CTLA-4 não mostrou diferença significativa entre os dois grupos estudados. CONCLUSÕES: Os marcadores genéticos que melhor caracterizaram e discriminaram diabéticos e não diabéticos foram os alelos de HLA DQA1 e DQB1.

Construction of recombinant retroviral vector with rat Islet-1 gene / 吉林大学学报(医学版)

Objective To isolate the rat insulin gene enhancer binding protein 1(Islet-1)gene and construct plEGFP-C1-Islet-1 recombinant retroviral expression vector.Methods The cDNA encoding the rat Islet-1 gene was isolated by RT-PCR method,the cDNA was first cloned into PGET-1 TA vector to facilitate the sequence and then subcloned into the retroviral vector plEGFP-C1.plEGFP-C1-Islet-1 was transfected into PA317 packaging cells with lipofectamine 2000.Transformants were selected in medium containing G418.Results A 1 050 bp DNA fragment was obtained by RT-PCR;plEGFP-C1-Islet-1 recombinant retroviral expression vector was identified by restrictive enzymes digestion,PA317 cells transfected with recombinant vector expressed enhancer green fluorescent protein(EGFP).Conclusion The gene encoding the rat Islet-1 is obtained and plEGFP-C1-Islet-1 expression vector is constructed successfully.

Effect of synthetic peptide(P-15)on monolayer cell culture of neonatal rat pancreatic islet / 中国糖尿病杂志

The aim of this study was to investigate the effect of a synthetic fifteen-residue peptide, Gly-Thr-Pro-Gly-Pro-Gln-Gly-Ile-Ala-Gly-Gln-Arg-Gly-Val-Val(P-15),on islet cell insulin secretion and insulin gene expression.Wistar rat islets,isolated by collagenase and trypsin digestion,were exposed to 0,0. 72,7.2,36?mol/L P-15 with 16.7mmol/L glucose.Insulin release increased approximately twofold in re- sponse to the concentration of 7.2?mol/L P-15 and Northern-blot analysis of islet mRNA with a rat pre- proinsulin cDNA probe showed a concomitant increase in mRNA level as compared with levels observed in islets treated with control.It is concluded that P-15 not only can stimulate the release of insulin but also in- crease the preproinsulin mRNA expression of islet cells.