Mutations at the BLK locus linked to maturity onset diabetes of the young and beta-cell dysfunction.

Maturity-onset diabetes of the young (MODY) is a subtype of diabetes defined by an autosomal pattern of inheritance and a young age at onset, often before age 25. MODY is genetically heterogeneous, with 8 distinct MODY genes identified to date and more believed to exist. We resequenced 732 kb of genomic sequence at 8p23 in 6 MODY families unlinked to known MODY genes that showed evidence of linkage at that location.

Functional defect of truncated hepatocyte nuclear factor-1alpha (G554fsX556) associated with maturity-onset diabetes of the young.

A novel frameshift mutation attributable to 14-nucleotide insertion in hepatocyte nuclear factor-1alpha (HNF-1alpha) encoding a truncated HNF-1alpha (G554fsX556) with 76-amino acid deletion at its carboxyl terminus was identified in a Thai family with maturity-onset diabetes of the young (MODY). The wild-type and mutant HNF-1alpha proteins were expressed by in vitro transcription and translation (TNT) assay and by transfection in HeLa cells. The wild-type and mutant HNF-1alpha could similarly bind to human glucose-transporter 2 (GLUT2) promoter examined by electrophoretic mobility shift assay (EMSA).

The role of HSP70 on ENPP1 expression and insulin-receptor activation.

Ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) inhibits insulin-receptor (IR) signaling and, when over-expressed, induces insulin resistance in vitro and in vivo. Understanding the regulation of ENPP1 expression may, thus, unravel new molecular mechanisms of insulin resistance. Recent data point to a pivotal role of the ENPP1 3'UTR, in modulating ENPP1 mRNA stability and expression.

Mutations of maturity-onset diabetes of the young (MODY) genes in Thais with early-onset type 2 diabetes mellitus.

Objective: Six known genes responsible for maturity-onset diabetes of the young (MODY) were analysed to evaluate the prevalence of their mutations in Thai patients with MODY and early-onset type 2 diabetes.

Patients And Methods: Fifty-one unrelated probands with early-onset type 2 diabetes, 21 of them fitted into classic MODY criteria, were analysed for nucleotide variations in promoters, exons, and exon-intron boundaries of six known MODY genes, including HNF-4alpha, GCK, HNF-1alpha, IPF-1, HNF-1beta, and NeuroD1/beta2, by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method followed by direct DNA sequencing. Missense mutations or mutations located in regulatory region, which were absent in 130 chromosomes of non-diabetic controls, were classified as potentially pathogenic mutations.

PAX4 mutations in Thais with maturity onset diabetes of the young.

Context: Six maturity onset diabetes of the young (MODY) genes have been discovered to date but account for a small proportion of MODY among Asians, suggesting the existence of other MODY genes in this racial group.

Objective: The aim of this study was to investigate whether or not genetic variants in PAX4, a crucial transcription factor in beta-cell development, contribute to MODY in Thais.

Design And Methods: We screened PAX4 coding sequences in 46 MODY probands without mutation in known MODY genes and in 74 nondiabetic controls using PCR-single-stranded conformational polymorphism analysis followed by direct sequencing.

Tag polymorphisms at the A20 (TNFAIP3) locus are associated with lower gene expression and increased risk of coronary artery disease in type 2 diabetes.

A20 or tumor necrosis factor (TNF)-induced protein 3 (TNFAIP3) is a negative regulator of nuclear factor-kappaB (NF-kappaB). We have investigated whether polymorphisms in this gene are associated with increased atherosclerosis in diabetic patients. Five tag single nucleotide polymorphisms (SNPs) were typed in 479 type 2 diabetic patients from Boston, including 239 coronary artery disease (CAD)-positive case subjects and 240 CAD-negative control subjects.

Analysis of the reg1alpha and reg1beta gene transcripts in patients with fibrocalculous pancreatopathy.

Fibrocalculous pancreatopathy is a form of diabetes, associated with tropical chronic calcific pancreatitis, in which islet beta-cell loss and pancreatic stone formation are found. It is likely to be a multifactorial disease with both genetic and environmental components. Regenerating (reg) gene encodes protein that has been involved in pancreatic lithogenesis and the regeneration of islet cells and therefore the abnormality of reg genes could be associated with fibrocalculous pancreatopathy.

Flow cytometry for the analysis of T cells expressing CD69 after stimulation with glutamic acid decarboxylase.

Type 1 diabetes mellitus is a T-cell mediated autoimmune disease in which the insulin-producing pancreatic beta cells are selectively destroyed. We recently found that the detection of cell-mediated immune response to glutamic acid decarboxylase (GAD) was more useful than the detection of specific autoantibodies for the diagnosis of type 1 diabetes mellitus. In this study, we established a flow cytometric analysis for the detection of activated T cells in whole venous blood, obtained from diabetic patients and normal controls after stimulation by GAD.

Cell-mediated immune responses to GAD and beta-casein in type 1 diabetes mellitus in Thailand.

We measured the cell-mediated immune response to GAD and bovine beta-casein in 38 type 1 and 37 type 2 diabetic patients who visited diabetic clinics or who were hospitalized in Bangkok, Thailand, and in 43 normal controls, by using a lymphoproliferation assay. Positive results against GAD were found in 29/38 (76.3%) type 1, 6/37 (16.

No abnormalities of reg1 alpha and reg1 beta gene associated with diabetes mellitus.

In order to investigate whether there would be any association between abnormalities of either reg1 alpha or reg1 beta gene and diabetes mellitus in man, these two genes were analyzed in 42 patients with type 1 diabetes mellitus, 12 with fibrocalculous pancreatopathy, 37 with type 2 diabetes mellitus, and 22 normal controls, by PCR-SSCP analysis and nucleotide sequencing technique. Polymorphism in the reg1 alpha gene resulted in three mobility patterns in the PCR-SSCP analysis, due to nucleotide constituents at position -10 before exon 1 being either C/C, T/C or T/T. These three mobility patterns were observed in every group of subjects.