Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

MODY is a form of NIDDM inherited as an autosomal dominant condition. We studied the linkage of MODY to two loci: ADA and GLUT2 in two large pedigrees with nonradioactive microsatellite polymorphic systems. A positive linkage of ADA to MODY was recently demonstrated in the large RW pedigree. Formal linkage analysis excluded a tight linkage between ADA and MODY with a LOD score of -5.82 and -2.24 at a recombination fraction of 0.01 in the two families. This result suggests genetic heterogeneity in the molecular basis of MODY. GLUT2 is a candidate gene that is expressed in the liver and beta-cells of pancreatic islets. In the two families studied, the disease did not cosegregate with GLUT2 alleles. The LOD scores for GLUT2 were -7.79 and -1.9 at a recombination fraction of 0.001 in the two families, thus providing evidence against the involvement of GLUT2 in MODY.
Diabetes 1992 Aug
PMID:Linkage analysis of maturity-onset diabetes of the young with microsatellite polymorphisms. No linkage to ADA or GLUT2 genes in two families. 162 71

The human liver/islet glucose transporter (GLUT2), a candidate gene for diabetes, has been incorporated into a genetic linkage map for chromosome 3q using a (CA)n dinucleotide repeat polymorphism adjacent to the 3'-end of exon 4a. We have found a total of nine alleles ranging in length from 153 to 169 nucleotides in three racial groups and have determined the precise structure of the variable region for four of the alleles by DNA sequencing. Five alleles were found to be common to the American Black, Caucasian, and Pima Indian racial groups studied. One allele (169 bp) was unique to American Blacks, and another rare allele (153 bp) was found only in the Caucasian population studied. Observed heterozygosity of the polymorphism in the Caucasian (CEPH) reference pedigree collection is 60%, for American Blacks 71%, and for Pima Indians 53%. An independent study recently identified the same dinucleotide repeat and found six alleles in a Caucasian population (Froguel et al., 1991), a result that we confirm; however, our sequencing data indicate a different molecular structure for the polymorphism for some of the alleles. We have constructed a new genetic linkage map of chromosome 3q uniquely placing the GLUT2 gene between flanking markers D3S26 and D3S43. The genetic map consists of 23 loci (25 RFLPs and 2 (CA)n dinucleotide repeat markers) with 14 markers uniquely localized with odds of at least 1000:1. Three genes (FTHL4, TF, GLUT2) are integrated into the map, which spans a sex-average distance of 147.3 cM, 103.8 cM in males and 227.0 cM in females.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mapping the human liver/islet glucose transporter (GLUT2) gene within a genetic linkage map of chromosome 3q using a (CA)n dinucleotide repeat polymorphism and characterization of the polymorphism in three racial groups. 163 77

The liver/islet glucose transporter (GLUT2) is expressed in the liver and in the Beta cells of pancreatic islets and is a candidate gene for the inherited defect in Type 2 (non-insulin-dependent) diabetes mellitus. A series of restriction fragment length polymorphisms have been identified using a GLUT2 cDNA probe with five restriction enzymes in a British white Caucasian population. Five independent restriction fragment length polymorphisms detected by restriction enzymes EcoRI (two restriction fragment length polymorphisms termed EcoRI-1, EcoRI-2), TaqI (two restriction fragment length polymorphisms termed TaqI-1, TaqI-2), and BclI (BclI-2) were used to construct GLUT2 haplotypes. Significant linkage disequilibrium was observed between four polymorphic sites EcoRI-2, TaqI-1, TaqI-2 and BclI-2 but linkage disequilibrium was not observed with EcoRI-1 polymorphic site and the other four sites. The frequencies of GLUT2 restriction fragment length polymorphisms and haplotypes in 50 Type 2 diabetic subjects and 50 non-diabetic control subjects show no significant differences suggesting that it is unlikely that there is a single major defect of this gene contributing to the inherited susceptibility to Type 2 diabetes in a Caucasian population.
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PMID:Multiple restriction fragment length polymorphisms at the GLUT2 locus: GLUT2 haplotypes for genetic analysis of type 2 (non-insulin-dependent) diabetes mellitus. 168 29

Exercise training results not only in enhanced insulin sensitivity but also in a reduction in insulin secretion. In this study, we examined the effects of exercise training on the expression of genes potentially related to insulin synthesis and glucose-stimulated insulin release by measuring pancreatic islet proinsulin, glucose-transporter (GLUT2), and glucokinase mRNAs. Female Wistar rats were subjected to 100 min of running at 25 m.min-1 up a 15% incline for 90 min/day for 6 days/wk for 3 wk. Pancreatic mRNA was evaluated by Northern- and dot-blot analysis with [32P]cRNA probes. We found no change in the pancreatic content of GLUT2 mRNA but found marked decreases in the content of proinsulin mRNA (78%, P less than 0.005) and glucokinase mRNA (65%, P less than 0.001). These results suggest that exercise modulates both islet glucose metabolism and insulin synthesis at the level of gene expression. Furthermore, there was a significant correlation between the decreases in glucokinase and proinsulin mRNA concentrations (r = 0.95, P less than 0.001), suggesting that expression of these genes is regulated in parallel.
Diabetes 1991 Mar
PMID:Coordinate reduction of rat pancreatic islet glucokinase and proinsulin mRNA by exercise training. 170 26

Previously, demonstrated that GLUT2 mRNA and protein are increased in liver of streptozocin-induced diabetic rats. To examine the mechanisms whereby GLUT2 mRNA is regulated, we cultured isolated hepatocytes in the absence and presence of various concentrations of glucose. Culture of hepatocytes in high glucose concentration (27.8 mM) for 20 h induced a 3.2-fold increase in GLUT2 mRNA levels compared with hepatocytes cultured without D-glucose. Interestingly, D-mannose and D-fructose could substitute for D-glucose to elevate the GLUT2 mRNA level, whereas 3-O-methyl-D-glucose, 2-deoxy-D-glucose, and sucrose, which were not metabolized or taken up by the cells, were without effect. Insulin had no significant effect on GLUT2 mRNA levels in hepatocytes in the presence or absence of D-glucose. Therefore, the regulation of the GLUT2 gene by D-glucose in hepatocytes is contrary to that reported for GLUT1 and GLUT4 genes, which are downregulated by D-glucose. These results also suggest that the elevated GLUT2 mRNA level observed in diabetic rat liver is due to the high blood glucose concentration rather than to insulin deficiency.
Diabetes 1992 Jan
PMID:Upregulation of GLUT2 mRNA by glucose, mannose, and fructose in isolated rat hepatocytes. 172 34

Obese KKAy insulin-resistant mice represent a model for the human syndrome of noninsulin-dependent diabetes mellitus. As such, the animals are hyperglycemic and hyperinsulinenic. Treatment of KKAy mice with pioglitazone, a new antihyperglycemic agent, lowered elevated blood glucose and insulin levels to near normal. Since hepatic glucose overproduction is a key abnormality in noninsulin-dependent diabetes mellitus, the aim of the present study was to define the specific effects of pioglitazone on hepatic glucose metabolism and release. To do so, we evaluated the expression of the major liver glucose transporter, GLUT2, and examined the activity and expression of the major rate-limiting enzyme for gluconeogenesis, phosphoenolpyruvate carboxykinase. Our results showed that GLUT2 mRNA abundance was unchanged in diabetic KKAy mice compared to nondiabetic animals, and that no changes were elicited by pioglitazone treatment. Such unaltered GLUT2 levels were consistent with a role for liver GLUT2 in bidirectional transport of glucose during physiological states of uptake or release. In contrast, phosphoenolpyruvate carboxykinase activity and mRNA abundance were concordantly elevated 2-fold in diabetic animals and were returned to normal levels after treatment with pioglitazone. Given that pioglitazone therapy led to decreased hepatic gluconeogenesis while insulin levels were concomitantly lowered, it appeared that pioglitazone acted to restore sensitivity to insulin's normal inhibitory actions.
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PMID:Treatment of insulin-resistant mice with the oral antidiabetic agent pioglitazone: evaluation of liver GLUT2 and phosphoenolpyruvate carboxykinase expression. 173 21

We used antibodies to the fat/muscle glucose transporter (GLUT4) and the liver glucose transporter (GLUT2) to measure levels of these proteins in various tissues of two rodent models of non-insulin-dependent (type II) diabetes mellitus: the obese spontaneously diabetic male Zucker fa/fa rat (ZDF/drt) and the male viable yellow Avy/a obese diabetic mouse. The ZDF/drt strain generally develops overt diabetes associated with decreased plasma insulin levels. Depending on the age of the animals, the ZDF/drt rats can be arbitrarily segregated into age-matched obese, mildly diabetic (blood glucose less than 11 mM) and obese, and severely diabetic (blood glucose greater than 20 mM) groups. Avy/a mice are comparably hyperglycemic but unlike the ZDF/drt rats are severely hyperinsulinemic. In both groups of diabetic animals, GLUT4 in adipose tissue, heart, and skeletal muscle was reduced 25-55%, and GLUT2 in liver was increased 30-40%, relative to lean, age-matched controls. However, when the mildly diabetic ZDF/drt rats were compared to the lean controls, the only significant difference was a 25% reduction of GLUT4 in heart. Within all of the ZDF/drt rats (excluding the lean controls), GLUT2 in liver and GLUT4 in adipose tissue, heart, and skeletal muscle correlated significantly with glycemia. These data suggest that, in these two models of type II diabetes, glucose transporter levels in muscle, adipose tissue, and liver are regulated in a tissue-selective manner in response to changes in insulin and glucose. Furthermore, at least in the ZDF/drt rat, alterations in GLUT2 and/or GLUT4 protein levels appear not to be associated with obesity per se but appear to be secondary to the severely diabetic state.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes 1992 Feb
PMID:Glucose transporter levels in tissues of spontaneously diabetic Zucker fa/fa rat (ZDF/drt) and viable yellow mouse (Avy/a). 173 8

The liver/islet (GLUT2) and muscle/adipose tissue (GLUT4) glucose-transporter gene products, membrane proteins that facilitate glucose uptake into cells, are important molecules for normal carbohydrate metabolism. Recent isolation of the genes encoding these proteins provides a means to assess the role of possible defects that might contribute to impaired glucose-stimulated insulin secretion or impaired insulin-mediated glucose uptake, both prominent phenotypic features of non-insulin-dependent diabetes (NIDDM). A GLUT2 cDNA clone was isolated from a human liver cDNA library to search for polymorphisms at this locus in American Blacks. Three highly polymorphic sites were identified, one of which (EcoRI-Hae III) appears to be due to an insertion and/or deletion of 200 base pairs of DNA. Significant linkage disequilibrium between these sites over approximately 30 kilobases of genomic DNA suggested that these polymorphisms could be in linkage disequilibrium with mutations at this locus if they exist. A GLUT4 cDNA clone was also utilized to search for polymorphisms at this locus, but only one previously described polymorphism was observed. GLUT2 and GLUT4 cDNA probes were used to evaluate DNA polymorphisms in genomic DNA from American Blacks with NIDDM. The allelic, genotypic, and haplotypic frequencies of the DNA polymorphisms at these loci did not differ from the frequencies in nondiabetic subjects. Because no associations with NIDDM were found, it appears unlikely that mutations at these loci contribute in a major way to the genetic susceptibility to NIDDM observed in American Blacks.
Diabetes 1990 Dec
PMID:Polymorphisms of GLUT2 and GLUT4 genes. Use in evaluation of genetic susceptibility to NIDDM in blacks. 197 28

A radioimmunoassay for the GLUT1 glucose transporter was developed with a synthesized peptide based on the sequence of the cDNA for GLUT1. A peptide corresponding to the COOH-terminal domain of the GLUT1 glucose transporter (Thr-Pro-Glu-Glu-Leu-Phe-His-Pro-Leu-Gly-Ala-Asp-Ser-Gln-Val) was synthesized and conjugated to keyhole limpet hemocyanin through the NH2-terminal of the peptide. An antibody was raised against this complex and affinity purified with the immobilized peptide. A second peptide, with tyrosine residue added to the NH2-terminal of the above peptide, was synthesized and used as a standard and iodinated for preparation of the radioactive ligand. The assay is highly reproducible, sensitive, and specific for the COOH-terminal domain of the GLUT1 glucose transporter. It has no cross-reactivity with the other glucose-transporter isoforms GLUT2 and GLUT4. Furthermore, the results obtained with this radioimmunoassay on the number of glucose transporters in human erythrocytes were in good agreement with previous studies based on cytochalasin B binding, suggesting that this radioimmunoassay is able to quantify the number of glucose transporters. The assay is completed within 4 h and can be used for simultaneous measurement of GLUT1 in many samples. In addition, it can be applied to the measurement of GLUT1 in several types of tissue.
Diabetes 1991 Mar
PMID:Peptide-based radioimmunoassay specific for GLUT1 glucose transporter. 199 71

In order to investigate the regulation of glucose transporter gene expression in the altered metabolic conditions of obesity and diabetes, we have measured mRNA levels encoding GLUT2 in the liver and GLUT4 in the gastrocnemius muscle from various insulin resistant animal models, including Zucker fatty, Wistar fatty, and streptozocin(STZ)-treated diabetic rats. Northern blot analysis revealed that GLUT2 mRNA levels were significantly (P less than 0.001) elevated in 14 wk Zucker fatty and Wistar fatty rats relative to lean littermates but were similar in these two groups at 5 wk of age. Furthermore, there was significant increase (P less than 0.01) in GLUT2 mRNA levels in STZ diabetic rats at 3 wk after treatment. GLUT4 mRNA levels were not significantly different between control and insulin resistant rats in all animal models. These results indicate that neither hyperinsulinemia nor hyperglycemia affects GLUT4 mRNA levels in the muscle. However, GLUT2 mRNA levels in the liver were elevated in obesity and diabetes, although this regulatory event occurred independently from circulating insulin or glucose concentrations.
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PMID:Liver and muscle-fat type glucose transporter gene expression in obese and diabetic rats. 202 68


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