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T Satoh,
N Abiru,
M Kobayashi,
H Zhou,
K Nakamura,
G Kuriya,
H Nakamura,
Y Nagayama, E Kawasaki,
H Yamasaki,
L Yu,
G S Eisenbarth,
E Araki,
M Mori,
S Oyadomari,
K Eguchi
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ABSTRACT: C/EBP homologous protein (CHOP) has been proposed as a key transcription factor for endoplasmic reticulum (ER) stress-mediated β-cell death induced by inflammatory cytokines in vitro. However, the contribution of CHOP induction to the pathogenesis of type 1 diabetes is not yet clear. To evaluate the relevance of CHOP in the pathogenesis of type 1 diabetes in vivo, we generated CHOP-deficient non-obese diabetic (NOD.Chop (-/-)) mice. CHOP deficiency did not affect the development of insulitis and diabetes and apoptosis in β-cells. Interestingly, NOD.Chop (-/-) mice exhibited a delayed appearance of insulin autoantibodies compared to wild-type (wt) mice. Adoptive transfer with the diabetogenic, whole or CD8(+)-depleted splenocytes induced β-cell apoptosis and the rapid onset of diabetes in the irradiated NOD.Chop (-/-) recipients with similar kinetics as in wt mice. Expression of ER stress-associated genes was not significantly up-regulated in the islets from NOD.Chop (-/-) compared to those from wt mice or NOD-scid mice. These findings suggest that CHOP expression is independent of the development of insulitis and diabetes but might affect the early production of insulin autoantibodies in the NOD mouse.
Apoptosis 01/2011; 16(4):438-48. · 4.07 Impact Factor
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Y Kawabata,
H Ikegami,
T Awata,
A Imagawa,
T Maruyama, E Kawasaki,
S Tanaka,
A Shimada,
H Osawa,
T Kobayashi,
T Hanafusa,
K Tokunaga,
H Makino
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ABSTRACT: We sought to clarify similarities and differences in the contribution of HLA to genetic susceptibility to three subtypes of type 1 diabetes: acute-onset, fulminant and slowly progressive.
We genotyped 545 Japanese patients with type 1 diabetes (338 acute-onset, 80 fulminant, 127 slowly progressive) and 396 control participants at HLA-DRB1, -DQB1, -A, -B and -C, and at 101 candidate single nucleotide polymorphisms (SNPs) in an 8.5 Mb region of the extended HLA.
DRB1*0405-DQB1*0401, DRB1*0802-DQB1*0302 and DRB1*0901-DQB1*0303 were associated with acute-onset type 1 diabetes, with the DRB1*0405-DQB1*0401/DRB1*0802-DQB1*0302 genotype achieving the highest odds ratio of 42.7. DRB1*1501-DQB1*0602 and DRB1*1502-DQB1*0601 were negatively associated with acute-onset type 1 diabetes. A similar tendency was observed for slowly progressive type 1 diabetes. In contrast, only DRB1*0405-DQB1*0401 was associated with fulminant type 1 diabetes, with the DRB1*0405-DQB1*0401/DRB1*0405-DQB1*0401 genotype showing the highest odds ratio of 11.2. DRB1*0802-DQB1*0302, DRB1*0405-DQB1*0401/DRB1*0802-DQB1*0302 and DRB1*1501-DQB1*0602 were not associated with fulminant type 1 diabetes. The association of class I alleles and a panel of SNPs in an extended HLA region with fulminant type 1 diabetes was also different from that seen for the acute-onset and slowly progressive forms. The presence of both one and two susceptible haplotypes conferred susceptibility to slowly progressive type 1 diabetes, whereas the presence of two susceptible haplotypes was required to confer susceptibility to acute-onset and fulminant type 1 diabetes.
These data suggest that HLA associations with fulminant type 1 diabetes are qualitatively different from those with other subtypes of type 1 diabetes, whereas the HLA contribution to slowly progressive type 1 diabetes is qualitatively similar to, but quantitatively different from, that in acute-onset type 1 diabetes.
Diabetologia 10/2009; 52(12):2513-21. · 6.81 Impact Factor
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ABSTRACT: We determined the autoantibody profile in autoimmune thyroid diseases (AITD) and examined the distribution of thyroid-related autoantibodies in other autoimmune disorders.
We tested sera from 234 patients with Graves' disease (GD), 130 with Hashimoto's thyroiditis (HT), 249 with other autoimmune diseases, and 50 healthy controls by enzyme-linked immunosorbent assay or radioimmunoassay.
Autoantibodies except TSH receptor antibody (Ab), anti-thyroglobulin (Tg) Ab and anti-thyroid peroxidase (TPO) Ab were not significantly prevalent in patients with AITD despite a significantly high elevation of thyroid-related Ab. Significant prevalence of autoantibodies related to AITD was observed in type 1 diabetes patients. Elevation of anti-Tg Ab was seen in patients with primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH), and anti-TPO Ab was elevated in patients with PBC. Although the prevalence of anti-acetylcholine receptor Ab and systemic lupus erythematosus (SLE)- related Ab was significant in AIH, primary Sjögren's syndrome (pSS)-related Ab were also found in both liver diseases. In myasthenia gravis (MG) patients, thyroid-related Ab and pSS-related Ab were detected in both MG groups, although SLE-related Ab were limited to the anti-muscle specific kinase Ab-positive MG patients. In patients with connective tissue diseases, anti- Tg Ab and anti-TPO Ab were significantly prevalent.
Thyroid-related Ab were significantly elevated in all autoimmune diseases. Conversely, the elevations of Ab were not significant in the patients with AITD, suggesting a close relationship between AITD and other immune-mediated diseases.
Journal of endocrinological investigation 11/2008; 31(10):861-5. · 1.57 Impact Factor
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Y Murase,
A Imagawa,
T Hanafusa,
H Iwahashi,
Y Uchigata,
A Kanatsuka, E Kawasaki,
T Kobayashi,
A Shimada,
I Shimizu,
T Maruyama,
H Makino
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ABSTRACT: The aim of the present study was to assess the development of microangiopathy in patients with fulminant type 1 diabetes, a novel subtype of type 1B diabetes.
In a nationwide survey, we followed 41 patients with fulminant type 1 diabetes and 76 age- and sex-matched patients with type 1A diabetes for 5 years. The following data were recorded every 12 months after the onset of diabetes: seven-point blood glucose concentrations, HbA1c level, urinary albumin excretion, serum C-peptide level, blood pressure, daily dosages of insulin, frequency of severe hypoglycaemic episodes, and neurological and fundoscopic examination.
The 5-year cumulative incidence of microangiopathy was 24.4% in fulminant type 1 diabetes and 2.6% in type 1A diabetes. In longitudinal studies using the Kaplan-Meier method, the cumulative incidence of each form of microangiopathy was significantly higher in fulminant type 1 diabetes than in type 1A diabetes; retinopathy was 9.8% vs 0% (p=0.014), nephropathy 12.2% vs 2.6% (p=0.015) and neuropathy 12.2% vs 1.3% (p=0.010), respectively. Mean HbA1c levels were similar in the fulminant and type 1A diabetes groups during the follow-up periods. However, the mean M-value, mean insulin dosages and the frequency of severe hypoglycaemic episodes were significantly higher, and the mean postprandial C-peptide level was significantly lower in the fulminant type 1 diabetes group.
These data suggest that patients with fulminant type 1 diabetes are a high-risk subgroup for diabetic microangiopathy associated with the lack of endogenous insulin secretion from the onset of diabetes.
Diabetologia 04/2007; 50(3):531-7. · 6.81 Impact Factor
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ABSTRACT: Type 1 diabetes is a multifactorial disease which results from a T-cell-mediated autoimmune destruction of the pancreatic beta cells in genetically predisposed individuals. The risk for individuals of developing type 1 diabetes varies remarkably according to country of residence and race. Japan has one of the lowest incidence rates of type 1 diabetes in the world, and recognises at least three subtypes of the condition: acute-onset ('classical'), slow-onset, and fulminant type 1 diabetes. The incidence rate of type 1 diabetes in children aged 0-14 years in Japan increased over the period from 1973-1992, but remained constant over the last decade, averaging 2.37 cases per 100,000 persons per year; the incidence does not appear to have increased in older age groups. Although there are few reports regarding the incidence and prevalence of type 1 diabetes in adult-onset patients, it appears that the prevalence of type 1 diabetes in adults is more than twice that in childhood-onset patients and that two-thirds of them have a slow-onset form of type 1 diabetes. Differences and similarities in the association of MHC and non-MHC genes with type 1 diabetes are observed in Japan and in countries with Caucasoid populations. Highly susceptible class II HLA haplotypes identified in patients of Caucasoid origin are rarely seen in Japanese patients, whereas protective haplotypes are universal. Non-MHC genes associated with susceptibility to type 1 diabetes in both Japanese and Caucasoid patients include polymorphisms in the insulin gene, the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene, the interleukin-18 (IL18) gene and the major histocompatibility complex class I chain-related gene A (MICA) gene. Fulminant type 1 diabetes is a unique subtype of type 1 diabetes that accounts for about 20% of acute-onset type 1 diabetes, and is seen mainly in adults. The challenge for the future is to investigate the underlying pathogenesis of beta cell destruction, including the genetic or environmental factors that may modify the form of onset for each subtype of Japanese type 1 diabetes.
Diabetologia 06/2006; 49(5):828-36. · 6.81 Impact Factor
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I Shimizu,
H Makino,
A Imagawa,
H Iwahashi,
Y Uchigata,
A Kanatsuka, E Kawasaki,
T Kobayashi,
A Shimada,
T Maruyama,
T Hanafusa
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ABSTRACT: The objective of this study was to characterize the clinical and immunogenetic features of Japanese pregnancy-associated fulminant type 1 diabetes (PF). A group of patients with PF was compared with a group of patients of child-bearing age with fulminant type 1 diabetes that was not associated with pregnancy (NPF) in a nationwide survey conducted from 2000-2004.
The clinical characteristics of the 22 patients in the PF group were compared with those of the 48 patients in the NPF group. Human leukocyte antigen (HLA) class II DR and DQ genotyping of 17 PF and 20 NPF patients was performed.
Arterial pH was significantly lower (P = 0.0366), and amylase values tended to increase in PF patients compared with NPF patients (P = 0.0515). In 22 PF patients, 18 developed disease during pregnancy (26.3 wk; range, 7-38), whereas four cases occurred immediately after delivery (10.5 d; range, 7-14 d). Twelve cases that developed during pregnancy resulted in stillbirth (67%), and five of the six fetal cases that survived were delivered by cesarean section. The haplotype frequency of HLA DRB1*0901-DQB1*0303 in PF was significantly higher than those in NPF (P = 0.0244) and controls (P = 0.0001), whereas that of DRB1*0405-DQB1*0401 in NPF was significantly higher than those in PF (P = 0.0162) and controls (P < 0.0001).
The clinical symptoms of PF patients were more severe than those of NPF patients, and the prognosis of their fetuses was extremely poor. The type 1 diabetes-susceptible HLA class II haplotype is distinct in PF and NPF patients, suggesting that different HLA haplotypes underlie the presentation of PF or NPF.
Journal of Clinical Endocrinology & Metabolism 03/2006; 91(2):471-6. · 6.50 Impact Factor
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ABSTRACT: Fulminant type 1 diabetes, which is characterised by a markedly acute onset of diabetes and an absence of islet-related autoantibodies, accounts for 20% of type 1 diabetes in Japan. We aimed to clarify the contribution of the HLA subtype to fulminant type 1 diabetes in Japanese.
We determined the serological subtypes of HLA-A, -DR and -DQ in 115 patients with fulminant type 1 diabetes, 98 patients with typical type 1A diabetes and 190 normal control subjects.
The frequency of HLA-DR4, but not DR9, was significantly higher in fulminant type 1 diabetes, while those of HLA-DR1, DR2, DR5 and DR8 were significantly lower than those in controls. In contrast, DR9 but not DR4 was more frequent and DR2 was extremely rare in typical type 1A diabetes. Haplotype analysis revealed that DR4-DQ4 was significantly more frequent, and both DR2-DQ1 and DR8-DQ1 were less frequent in fulminant diabetes. In type 1A diabetes, DR2-DQ1 was extremely rare while DR9-DQ3 was significantly more frequent. In the combination analysis, the homozygotes of DR4-DQ4 in fulminant type 1 diabetes and DR9-DQ3 in typical type 1A diabetes indicated high odds ratios (13.3 and 13.3, respectively).
Our results suggest that class II HLA contributes to the development of fulminant type 1 diabetes. Susceptibility and resistance of the HLA subtype to type 1 diabetes are distinct between fulminant and typical autoimmune type 1 diabetes.
Diabetologia 03/2005; 48(2):294-300. · 6.81 Impact Factor
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H Ida, E Kawasaki,
T Miyashita,
F Tanaka,
M Kamachi,
Y Izumi,
M Huang,
M Tamai,
T Origuchi,
A Kawakami,
K Migita,
M Motomura,
T Yoshimura,
K Eguchi
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ABSTRACT: To identify potential mutations in the tumour necrosis factor receptor superfamily 1A gene (TNFRSF1A) in a Japanese female patient with recurrent fever complicated by systemic lupus erythematosus (SLE), and in her family members.
DNA sequencing of exons 1-10 of the TNFRSF1A gene was performed to determine mutations that might be associated with the tumour necrosis factor receptor-associated periodic syndrome (TRAPS). Moreover, the TNFRSF1A gene was examined in Japanese patients with autoimmune diseases, including SLE, rheumatoid arthritis (RA), mixed connective tissue disease (MCTD) and Behçet's disease, and in healthy Japanese controls. Enzyme-amplified sensitivity immunoassay (EASIA) analysis was used to assess serum levels of TNF, the 55-kDa TNF receptor (TNFRSF1A) and the 75-kDa TNF receptor (TNFRSF1B). Membrane TNFRSF1A expression was analysed on the surface of peripheral blood mononuclear cells by flow cytometry.
A novel mutation, a heterozygous C to T transition in exon 3 which substitutes an isoleucine for a threonine at position 61 (T61I) was detected in the TNFRSF1A gene derived from the genomic DNA of a Japanese female TRAPS patient. Two nieces and one nephew, all with a similar clinical phenotype, also possessed the same TNFRSF1A mutation. We further demonstrated the same mutation in five of 60 SLE patients (8.3%) and in five of 120 healthy individuals (4.2%), with no significant differences. Although high titres of serum TNF and soluble TNFRSF1B protein were observed in this patient, low titres of soluble TNFRSF1A protein were detected. However, a defect in TNFRSF1A shedding in vitro was not observed in monocytes derived from this patient.
This is the first report of a TRAPS patient associated with SLE with a novel TNFRSF1A mutation (T61I).
Rheumatology 11/2004; 43(10):1292-9. · 4.06 Impact Factor
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Annals of the Rheumatic Diseases 12/2003; 62(11):1117-8. · 8.73 Impact Factor
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ABSTRACT: It has been reported that fulminant type 1 diabetes is a novel subtype of type 1B diabetes. However, whether the etiology of fulminant type 1 diabetes is associated with an autoimmune or nonautoimmune process remains to be solved. In order to further characterize fulminant type 1 diabetes, we compared the clinical, immunological and genetic characteristics with those of acute-onset type 1A diabetes. Nine patients with fulminant diabetes and nine patients with acute-onset type 1A diabetes, who had been newly diagnosed during 1998-2001, were analyzed. In female patients of child-bearing age, the onset of diabetes occurred during pregnancy or after delivery in three cases of six fulminant cases, but not in any of seven type 1A diabetes. Eight of nine fulminant patients had fever immediately prior to the onset of hyperglycemic symptoms, whereas only one of nine type 1A patients had this (P=0.002). In Japanese type 1 susceptible HLA haplotypes, DRB1*0901-DQB1*0303 was more frequent in type 1A diabetes than fulminant diabetes (7/18 vs. 0/18, P=0.004), whereas the frequency of DRB1*0405-DQB1*0401 was similar (type 1A 4/18 vs. fulminant 6/18). Therefore, pregnancy, possible viral infection, or HLADRB1*0405-DQB1*0401 may contribute to the onset of fulminant type 1 diabetes.
Diabetes Research and Clinical Practice 11/2003; 62(1):33-8. · 2.75 Impact Factor
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M Ozaki,
H Yamasaki,
H Kondo,
S Yamasaki,
N Fujita,
M D Yamauchi,
T Abe,
K Yamakawa,
Y Sera,
S Uotani, E Kawasaki,
H Takino,
H Kijima,
T Kondo,
Y Yamaguchi,
K Eguchi
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ABSTRACT: Glutathione (GSH) participates in deoxidization and elimination of hydrogen peroxide and other reactive oxygen species, and plays an important part in the antioxidant system. To investigate the effect of GSH content on insulin gene expression, we utilized a stable transfectant, designated as ribo-MIN6 cells, which were stably transfected with the ribozyme of gamma-glutamylcysteine synthetase (gamma-GCS), exhibiting approximately 50% reduction of intracellular GSH content. We transiently transfected a luciferase expression vector driven by human preproinsulin gene promoter spanning from -1998 to +237 (pINS-1998/luc) and several deletion constructs into ribo-MIN6. Furthermore, transient transfection with ribozyme vector and pINS-1998/luc into wild-type MIN6 cells was also carried out. Luciferase activity was about 9-fold higher in ribo-MIN6 cells as compared to wild-type MIN6 cells. In the transient transfection of pINS-1998/luc with gamma-GCS ribozyme vector into wild-type MIN6 cells, the luciferase activity was increased in proportion to the added amounts of ribozyme vector. In transfection with deletion constructs, two major sites were found to be critical for insulin promoter activity. For the wild-type MIN6 cells, regions important for the promoter activity were also located at regions similar to those of ribo-MIN6 cells. Our results suggest that the suppression of intracellular GSH level might, in part, regulate the insulin gene expression.
Diabetes, nutrition & metabolism 05/2003; 16(2):81-7.
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N Fujita,
H Yamasaki,
K Yamakawa,
S Uotani,
H Kuwahara,
M Degawa-Yamauchi,
T Abe,
M Ozaki,
Y Sera, E Kawasaki,
H Takino,
Y Yamaguchi,
K Eguchi
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ABSTRACT: To investigate the mechanism of severe impairment of insulin action in type B insulin resistance, we extracted IgG from the serum of a patient with type B insulin resistance (B-IgG) and analyzed the inhibiting effect of B-IgG not only on insulin signaling but also on IGF-I signaling in Chinese hamster ovary (CHO) cells expressing human insulin receptor or human IGF-I receptor. Preincubation with 1 mg/ml B-IgG prevented insulin-induced phosphorylation of insulin receptor and insulin receptor substrate-1 (IRS-1) but did not alter the IGF-I-induced phosphorylation of the IGF-I receptor and IRS-1. (125)I-insulin binding was inhibited by 93% after preincubation with B-IgG at 37 degrees C and was recovered up to 50% of the control value by acid washing. However, when cells were preincubated with B-IgG at 4 degrees C, the insulin binding completely recovered the control value by acid washing. (125)I-IGF-I binding was not altered by B-IgG preincubation. Immunoblot study revealed that the protein level of the insulin receptor was strongly decreased by preincubation with 1 mg/ml B-IgG at 37 degrees C, but never at 4 degrees C. The IRS-1 protein level did not change by B-IgG preincubation. In order to know the role of the insulin receptor internalization in the inhibiting effect of B-IgG, we employed CHO cells expressing mutant insulin receptors which do not undergo internalization (CHO-K1018R). B-IgG incubation of CHO-K1018R at 37 degrees C failed to decrease the protein level of the insulin receptor. The present data indicate that IgG from the diabetic patient with type B insulin resistance decreased insulin receptor protein level, probably due to the enhanced degradation rate of the insulin receptor, in which insulin receptor tyrosine kinase activity and internalization are required for this process. This effect of B-IgG was specific for the insulin receptor with no effect on either IGF-I receptor or IRS-1, as reflected by the IGF-I effectiveness on glycemic control in this patient.
Acta Diabetologica 01/2003; 39(4):221-7. · 2.78 Impact Factor
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ABSTRACT: We evaluated the prevalence of GAD Ab in Japanese Type 2 diabetic patients treated with oral hypoglycaemic agents (OHA) and/or diet and followed GAD Ab(+) patients to assess the usefulness of GAD Ab as a marker for future insulin treatment prospectively.
A total of 2658 Japanese Type 2 diabetic patients treated by OHA and/or diet were randomly selected between April 1996 and December 1998. The clinical characteristics at entry were assessed and patients were followed for 1-3 years.
The overall prevalence of GAD Ab among Type 2 diabetic patients was 2.0%. Forty-five had a history of diabetes of < or = 5 years (short history) while those with duration > 5 years (long history) totalled nine. Among them, 47% of patients with a short history did not require insulin in the follow-up period. However, none of those with a long history required insulin treatment within 2 years. Comparison of patients based on GAD titre in those with short history showed that 33% of patients in the high-titre group (> or = 20 U) required no insulin treatment in the first year of follow-up. In contrast, this proportion was 80% in the first and 67% in the second year in the low-titre group (< 20 U).
The prevalence of GAD Ab in Japanese patients with a short and long history of diabetes was 2.8% and 0.9%, respectively. The presence of GAD Ab in Japanese Type 2 diabetic patients with a short history of diabetes is a marker for early insulin treatment.
Diabetic Medicine 10/2002; 19(9):730-4. · 2.90 Impact Factor
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E Kawasaki,
Y Sera,
N Fujita,
M Yamauchi,
M Ozaki,
T Abe,
K Yamakawa,
S Uotani,
H Takino,
H Yamasaki,
Y Yamaguchi,
Y Uchigata,
N Matsuura,
K Eguchi
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ABSTRACT: The IA-2 is a major autoantigen of type 1 diabetes belonging to the protein tyrosine phosphatase family. We report on the humoral autoimmunity to an alternatively-spliced variant of IA-2 (IA-2 variant) and autoimmune-mediated diabetes age of onset association with IA-2 autoantibody epitope specificities, in 144 recent-onset patients with type 1 diabetes and 54 GAD autoantibody-positive patients with type 2 diabetes. The cytoplasmic domain of IA-2 (IA-2ic) detected a somewhat greater proportion of patients expressing autoantibodies than IA-2 variant (56%vs. 52% of patients with type 1 diabetes and 17%vs. 9% of GAD autoantibody-positive patients with type 2 diabetes). Conversely, only 1% of IA-2 variant autoantibody-positive patients failed to react to IA-2ic construct. Among 80 patients with type 1 diabetes who were positive for autoantibodies to IA-2ic, 8% recognized the juxtamembrane region (JM, representing amino acids 601-629) only, 64% bound the protein tyrosine phosphatase (PTP)-like domain of IA-2 only, and 29% bound both JM and PTP epitopes. Autoantibodies to the PTP-like domain were prevalent in children and adolescents with type 1 diabetes. The age of disease onset in patients with IA-2JM autoantibodies only, was significantly higher than those in patients reacted with the PTP-like domain of IA-2 (P< 0.02). Among GAD autoantibody-positive patients with type 2 diabetes reacted with IA-2ic, 44% bound the JM region only, and 33% bound epitopes in the PTP-like domain only; 22% had autoantibodies to both regions. The frequency of GAD autoantibody-positive patients with type 2 diabetes positive for autoantibodies to the JM region only, was significantly higher than that in patients with type 1 diabetes (P< 0.01). IA-2PTP autoantibodies were significantly associated with HLA-DR4, while the additional reactivity to IA-2JM was associated with HLA-DR9 allele. These results suggest that autoantibody recognition of IA-2 epitopes in autoimmune diabetes is associated with age of disease onset, which may reflect the intensity of the beta-cell destruction process.
Journal of Autoimmunity 12/2001; 17(4):323-31. · 7.37 Impact Factor
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T Abe,
Y Yamaguchi,
H Takino,
N Fujita,
M Yamauchi-Degawa,
M Ozaki,
K Yamakawa,
Y Sera,
H Sakamaki,
S Uotani, E Kawasaki,
T Awata,
H Yamasaki,
K Eguchi
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ABSTRACT: The mode of onset is occasionally similar in Type 1 and Type 2 diabetes mellitus, and some patients with Type 2 diabetes are positive for antiglutamic acid decarboxylase antibody (GAD Ab). We investigated the contribution of Type 1 diabetes susceptibility genes to the progression of the insulin-deficient state and mode of onset of Type 2 diabetes in GAD Ab-positive (GAD-Ab+) patients. We examined the variable number of tandem repeats in the promoter region of the insulin gene (INS-VNTR, insulin-dependent diabetes mellitus (IDDM) 2) and cytotoxic T lymphocyte antigen 4 (CTLA4, IDDM12) as representative of Type 1 diabetes susceptibility genes.
Patients with Type 2 diabetes who were GAD-Ab+ (n = 51) were selected for this study. In INS-VNTR, the class I allele was classified according to length (1S, 25-38 repeat units; 1M, 39-41 repeat units; 1L, 42-44 repeat units) and the exact class I allele length was analysed by specific polymerase chain reaction (PCR) amplifications. Analyses of classes II and III were performed by Southern blot. CTLA4 gene polymorphism (exon 1 position 49, G/A) was analysed by PCR-restriction fragment length polymorphism.
The distribution of INS-VNTR was no different between Type 1 diabetes and Type 2 diabetes with GAD Ab. The allele frequencies of CTLA4 gene polymorphism G and A in Type 2 diabetes/GAD-Ab+ were significantly different from those of Type 1 diabetes/GAD-Ab+ (G: 53%, A: 47% vs. G: 84%, A: 16%; P < 0.0001).
Our data showed that GAD-Ab+ Japanese patients presenting with Type 2 diabetes have shifted A allele while patients with abrupt onset have shifted G allele of CTLA4 gene polymorphism. Our results suggest that immunological function and polymorphism of the CTLA4 gene may contribute to the pathogenesis and progression of Type 1 diabetes.
Diabetic Medicine 09/2001; 18(9):726-31. · 2.90 Impact Factor
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ABSTRACT: Autoantibodies against IA-2 have been detected in up to 86% of newly diagnosed patients with type 1 diabetes and appear to identify a subgroup of prediabetic subjects who rapidly progress to type 1 diabetes. We examined the association of IA-2 gene polymorphism with type 1 diabetes in Japanese subjects. A total of 276 Japanese subjects were studied for disease association and, in addition, another 53 patients were studied for association with the autoantibody status to IA-2. A microsatellite marker D2S1753E, located in the intron of the IA-2 gene, was used as a genetic marker in this study. In Japanese, two alleles (161mu and 165mu) were more frequent, and the 163mu allele was less frequent than in Caucasians (p = 0.0001). There was no significant difference in frequencies of alleles between diabetic patients and control subjects. The frequency of IA-2 gene polymorphism was not significantly different between patients stratified by age-at-onset, or between patients with and without susceptible HLA, DRB1*0405, DRB1*0802 and DRB1*0901. There was no significant difference in allele frequency of the IA-2 gene polymorphism between patients with and without autoantibody to IA-2. In conclusion, IA-2 gene polymorphism is not associated with either susceptibility to, or heterogeneity in type 1 diabetes in Japanese subjects.
Human Immunology 06/2001; 62(5):518-22. · 2.84 Impact Factor
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Nippon rinsho. Japanese journal of clinical medicine 03/2001; 59 Suppl 2:421-5.
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ABSTRACT: With the recent cloning and recombinant expression of novel islet autoantigens, it is possible to investigate whether the quantitative expression of autoantibodies to these molecules is correlated with the semiquantitative titration of islet cell antibodies (ICA). To estimate the regional difference in the degree of association between these autoantibodies, autoantibodies reacting with ICA512/IA-2 (ICA512) and GAD65 in addition to ICA were analyzed in 131 Korean children with type 1 diabetes. Among the 131 type 1 diabetes patients, 36% was ICA512-positive, 56% was anti-GAD65-positive, and 43% was ICA-positive. However, in a subset of these with recent onset (<1 year), the prevalences of ICA512, anti-GAD65, and ICA were 75%, 75%, and 87.5%, respectively. ICA512 as well as anti-GAD65 were significantly associated with the presence of ICA. Among type 1 diabetes patients, 69% had one or more and 43% had two or more of these autoantibodies. Autoantibodies to ICA512 and anti-GAD65 were observed in 40 and in 41 of 56 ICA-positive subjects, respectively. Furthermore, ICA512 or anti-GAD65 were positive in 97% (34 of 35) and 100% (22 of 22) of patients with ICA levels > or =20 JDF-u and > or =40 JDF-u, respectively. The titer of ICA correlated with those of ICA512 (r=0.41, p<0.001) and anti-GAD65 (r=0.49, p<0.001). Both the prevalences and the titers of ICA512 or anti-GAD65 were strongly correlated with those of ICA even in Korean type 1 diabetes patients. ICA512 and anti-GAD65 in combination may be considered to be an alternative to ICA.
Acta Diabetologica 01/2001; 38(1):51-6. · 2.78 Impact Factor
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H Kondo,
S Mori,
H Takino,
H Kijima,
H Yamasaki,
M Ozaki,
I Tetsuya,
Y Urata,
T Abe,
Y Sera,
K Yamakawa, E Kawasaki,
Y Yamaguchi,
T Kondo,
K Eguchi
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ABSTRACT: Low levels of intracellular antioxidant enzyme activities as well as glutathione (GSH) concentrations have been described in pancreatic beta cells. We examined the effects of intracellular GSH depletion on insulin secretion and the role of intracellular GSH in signal transduction in beta cell line, MIN6 cells. Anti-gamma-glutamylcysteine synthetase (gamma-GCS) heavy subunit ribozyme was stably transfected to MIN6 cells to reduce intracellular GSH concentration. In the presence of 10 mM glucose, ribozyme-transfected cells (RTC) increased insulin secretion from 0.58 microg/10(6) cells/h in control cells (CC) to 1.48 microg/10(6) cells/h. This was associated with increased intracellular Ca(2+) concentration in RTC, detected by fluo-3 staining. Our results demonstrated that intracellular GSH concentration might influence insulin secretion by MIN6 cells, and suggest that enhanced insulin secretion by beta cells conditioned by chronic depletion of GSH is mediated by increased intracellular Ca(2+) concentration.
Biochemical and Biophysical Research Communications 12/2000; 278(1):236-40. · 2.48 Impact Factor
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ABSTRACT: Advances in immunology, biochemistry, and molecular biology have combined to allow the development of a large series of autoantibody assays utilizing recombinantly produced autoantigens. Labeled target proteins can be readily produced by in vitro transcription and translation of relevant cloned cDNA. The assays are carried out in the fluid phase and for most assays are more specific and sensitive than ELISA based assays. For some antigens (e.g. insulin) though ELISA assays detect antibodies following immunization, workshops indicate they are almost worthless for the diagnosis and prediction of type 1A diabetes. This new generation of radioassays is usually carried out in 96-well microtiter filtration plates that allow high throughput. Given such assays, individuals at high risk for type 1A diabetes, celiac disease, and Addison's disease can now be readily identified.
Frontiers in Bioscience 12/2000; 5:E181-90. · 3.52 Impact Factor
