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Biomedical subjects

H F Gu

Publications and source records attributed to H F Gu.

8 recordsLinked to original sources

Genetic influences of the intercellular adhesion molecule 1 (ICAM-1) gene polymorphisms in development of Type 1 diabetes and diabetic nephropathy.

AIM: The intercellular adhesion molecule-1 (ICAM-1) gene is located on chromosome 19p13, which is linked to Type 1 diabetes (T1D). ICAM-1 expression is related to development of T1D and diabetic nephropathy. The present study aims to evaluate the genetic influence of ICAM-1 gene polymorphisms on the development of T1D and diabetic nephropathy. METHODS: Five valid single nucleotide polymorphisms (SNPs) were genotyped in 432 T1D patients (196 patients had diabetic nephropathy) and 187 non-diabetic control subjects by using dynamic allele-specific hybridization (DASH) and pyrosequencing. RESULTS: SNPs rs281432(C/G) and rs5498 E469K(A/G) had high heterozygous indexes. They were significantly associated with T1D [P = 0.026, OR = 1.644 (95% CI 1.138-2.376) and P < 0.001, OR = 2.456 (1.588-3.8)]. Frequencies of the C allele in SNP rs281432(C/G) and the A allele in SNP rs5498 E469K(A/G) increased stepwise from non-diabetic control subjects to T1D patients without diabetic nephropathy and T1D patients with diabetic nephropathy. Further analysis for these two SNPs indicated that T1D patients had increased frequency of the common haplotype C-A, in comparison with non-diabetic control subjects (38.1 vs. 32.1%, P = 0.035). CONCLUSION: The present study provided evidence that SNPs rs281432(C/G) and rs5498 E469K(A/G) in the ICAM-1 gene confer susceptibility to the development of T1D and might also be associated with diabetic nephropathy in Swedish Caucasians.

Adult↗

Association study between chromosome 10q26.11 and obesity among Swedish men.

OBJECTIVE: Proximal chromosome 10q26 was recently linked to waist/hip ratio in European and African-American families. The objective was to investigate whether genomic variation in chromosome 10q26.11 reflects variation in obesity-related clinical parameters in a Swedish population. DESIGN: Genetic association study of single-nucleotide polymorphisms (SNPs) in chromosome 10q26.11 and obesity-related clinical parameters was performed. Obesity was defined as body mass index (BMI) > or = 30 kg/m2. SUBJECTS: Swedish Caucasians comprising 276 obese and 480 nonobese men, 313 obese and 494 nonobese women, 177 obese and 163 nonobese patients with type 2 diabetes mellitus (T2DM), and 106 obese and 201 nonobese subjects with impaired glucose tolerance (IGT) patients. MEASUREMENTS: Genotypes of 11 SNPs at chromosome 10q26.11, and various obesity-related clinical parameters. RESULTS: Homozygosity of a common haplotype constructed by three SNPs, rs2185937, rs1797 and hCV1402327, covering an interval of 2.7 kb, was suggested to confer an increased risk for obesity of 1.5 among men (P = 0.043). The C allele frequency and homozygous genotype frequency of the rs1797 tended to be higher among obese compared to among nonobese men (P = 0.017 and 0.020, respectively). The distribution of BMI and diastolic blood pressure was higher among those with the C/C genotype (P = 0.022 and 0.0061, respectively). The obese and the nonobese groups were homogeneous over BMI subgroups with regard to rs1797 risk genotype distribution. There was no tendency for association between rs1797 and obesity among neither women nor T2DM nor IGT patients. CONCLUSION: We show support for association between proximal chromosome 10q26.11 and obesity among Swedish men but not women through the analysis of a haplotype encompassing 2.7 kb.

Adolescent↗

Leu7Pro polymorphism in the neuropeptide Y (NPY) gene is associated with impaired glucose tolerance and type 2 diabetes in Swedish men.

The neuropeptide Y (NPY) is a neuropeptide with a role in the regulation of satiety and energy balance of body weight, insulin release, cardiovascular and central endocrine systems. In order to evaluate whether the NPY gene variations contribute to development of type 2 diabetes (T2DM), we have performed a genetic association study for Leu7Pro (T1128 C) polymorphism of the NPY gene in impaired glucose tolerance (IGT) and T2DM. Genotyping experiments for this non-synonymous single nucleotide polymorphism (SNP) in 263 patients with T2DM, 309 subjects with IGT and 469 non-diabetic healthy individuals in Swedish Caucasians were performed by using Dynamic Allele Specific Hybridisation (DASH). We found that the frequencies of the "risk" allele C in the subjects with IGT and the patients with T2DM in Swedish men were 13 % (p = 0.002, OR = 3.70, 1.65 - 8.29 95 % CI) and 10 % (p = 0.007, OR = 4.80, 1.47 - 11.33 95 % CI) respectively, which were significantly higher than the C allele frequency in non-diabetic controls (6 %). Furthermore, we found that the carriers with TC and CC genotypes in the subjects with IGT in Swedish men had significantly higher fasting plasma glucose in comparison with the TT carriers (5.6 +/- 0.7 mmol/l vs. 5.2 +/- 0.7 mmol/l, p = 0.021). The present study thus provides the evidence that Leu7Pro polymorphism in the NPY gene is associated with IGT and T2DM in Swedish men, and indicates that the NPY gene variations contribute to development of T2DM. Questions of gender specificity may be explained by genetic backgrounds, sense of coherence for stress and other factors in environment.

Adult↗

Functional consequences of mutations in the MODY4 gene (IPF1) and coexistence with MODY3 mutations.

AIMS/HYPOTHESIS: The aim of this study was to examine the putative role of mutations in the insulin promoter 1 (IPF1) gene in early-onset diabetes. METHODS: We carried out mutation screening of the IPF1 gene in 115 Scandinavian families with at least two members with onset of diabetes younger than 40 years. The allele frequencies were also tested in 183 unrelated patients with late-onset Type II (non-insulin-dependent) diabetes mellitus and in 92 non-diabetic control subjects. RESULTS: Two novel IPF1 variants (G212R and P239Q) and one previously reported (D76N) IPF1 variant were identified in the 115 families (3.5%). The D76N variant was found in one MODY3 family (S315fsinsA of HNF1alpha) and also in two families with late-onset Type II diabetes. The P239Q variant was identified in two families with early-onset diabetes including one with MODY3 (R272C of HNF1alpha) and in three families with late-onset Type II diabetes. Despite the fact that the variants did not segregate completely with diabetes, the non-diabetic carriers of the IPF1 variants had increased blood glucose concentrations (p < 0.05) and reduced insulin:glucose ratios (p < 0.05) during an oral glucose tolerance test compared with non-diabetic family members without these variants. In addition, when the G212R and P239Q variants were expressed in cells without IPF1 i.e.. Nes2y cells, both variants showed about a 50% reduction in their ability to activate insulin gene transcription compared to wild-type IPF1, as measured by reporter gene assay. CONCLUSION/INTERPRETATION: Although mutations in the IPF-1 gene are rare in early- (3.5 %) and late-onset (2.7 % ) Type II diabetes, they are functionally important and occur also in families with other MODY mutations.

Aged↗

[Single nucleotide polymorphisms(SNPs)and SNP databases].

Along the rapid development of human genome sequencing project, the variation data of human DNA sequence has become more and more useful not only for studying the origin, evolution and the mechanisms of maintenance of genetic variability in human populations, but also for detection of genetic association in complex disease such as diabetes, obesity, hypertension, Alzheimer's disease, etc. In recent two years, the databases such as dbSNP, CGAP, HGBASE, JST and Go!Poly etc. to collect and exploit data of genomic polymorphisms mainly single nucleotide polymorphisms (SNPs) have been respectively established in the United States, European countries, Japan and China. This overview summarized the development and applications of those SNP databases and also discussed some issues regarding the potential improvement of accuracy of SNP data collected. China has one fifth population in the world. Therefore, development of the SNP database for Chinese populations is of importance in developing complete SNP databases of human genome and may also stimulate the further development of biomedical research and production in China.

Databases, Nucleic Acid↗

Characterization, chromosomal localization, and expression during hematopoietic differentiation of the gene encoding Arl6ip, ADP-ribosylation-like factor-6 interacting protein (ARL6).

Proliferation and differentiation of hematopoietic stem cells and progenitors are regulated by signals from the microenvironment, involving both secreted cytokines and adhesion molecules. The exact mechanisms by which cytokines act on hematopoietic development are still not well understood. To extend the molecular characterization of gene regulation during cytokine-induced hematopoiesis, we applied mRNA differential display to identify genes regulated when multipotent progenitor cells are allowed to differentiate into monocytes and neutrophils. Here we report the isolation and characterization of a gene that is downregulated during myeloid differentiation and encodes a 23-kDa protein with four putative transmembrane segments. The gene, which we named Arl6ip, is identical to a mouse gene recently identified by its physical interaction with ADP-ribosylation-like factor-6 (ARL6), belonging to the Ras superfamily. We add information on its full-length characterization as well as its regulation during hematopoiesis. It is expressed in all hematopoietic cell lineages, but the highest level of expression is found in early myeloid progenitor cells. Preliminary studies by immunofluorescence microscopy revealed that the ARL6IP protein is predominantly localized to intracytoplasmic membranes. This suggests an involvement of the Arl6ip gene in protein transport, membrane trafficking, or cell signaling during hematopoietic maturation.

Adaptor Proteins, Signal Transducing↗

Association between the human glycoprotein PC-1 gene and elevated glucose and insulin levels in a paired-sibling analysis.

We studied whether there is an association between the single nucleotide polymorphism c.533A>C (K121Q) in the glycoprotein PC-1 gene and features of the metabolic syndrome in case-control and intrafamily association studies in 922 subjects from Finland and Sweden. No difference was observed in the Q allele frequency between control subjects and type 2 diabetic subjects (12.9 vs. 15.1%). The QK genotype was associated with higher fasting plasma glucose (FPG) concentrations than the KK genotype in type 2 diabetic patients (P <0.001) and their relatives (P <0.05). A permutation test of siblings discordant for the QK and KK genotypes also showed that the nondiabetic siblings with the QK genotype had higher FPG (6.1 +/- 2.0 vs. 5.4 +/- 0.6 mmo/l, P <0.001) and fasting insulin (7.0 +/- 3.6 vs. 4.8 +/- 2.6 mU/l, P <0.05) concentrations than the carriers of the KK genotype. In addition, diabetic siblings with the QK genotype had higher systolic blood pressure (147.0 +/- 18.0 vs. 140.0 +/- 18.7 mmHg, P <0.05) and higher fasting (9.9 +/- 3.0 vs. 8.8 +/- 2.8 mmol/l, P <0.05) and 2-h plasma glucose (17.3 +/- 8.5 vs. 12.9 +/- 4.2 mmol/l, P < 0.05) concentrations than the diabetic carriers of the KK genotype. The present study shows that, although the Q allele of the human glycoprotein PC-1 gene is associated with surrogate measures of insulin resistance, it may not be enough to increase the susceptibility to type 2 diabetes.

Adult↗

Using PRINS for gene mapping in polytene chromosomes.

We have adapted the primed in situ labelling (PRINS) protocol for gene mapping in polytene chromosomes of two dipteran species. The method was used to localize the genes for the Balbiani ring (BR) 2.1 and the iron-regulatory protein 1A (IRP1A) in polytene salivary gland chromosomes of Chironomus tentans, and Drosophila melanogaster respectively. Two oligonucleotides, corresponding to the BR 2.1 and IRP1A genes, were used as primers and the whole procedure was performed within 3-4 h. The strong labelling with low background revealed the localization of the BR 2.1 gene in polytene chromosome IV of C. tentans and the IRP1A gene in polytene chromosome 3R83 of D. melanogaster. The results demonstrated that PRINS is a fast, sensitive and suitable approach for physical gene mapping in polytene chromosomes.

Animals↗