Developmental changes in desensitisation of c-Fos expression induced by repeated maternal separation in pre-weaned mice

Early-life stress has long-lasting effects on neuroendocrine and behaviour in adulthood. Maternal separation (MS) is used as a model of early-life stress and daily repeated MS (RMS) for 3 h during the first two postnatal weeks is widely used in rodent studies. However, it is not fully understood whether early-life animals desensitise/habituate to repeated stress. In the present study, we investigated the effects of daily RMS for 3 h and acute/single time MS (SMS) for 3 h on the plasma corticosterone level and c-Fos expression in the brain in mice at different postnatal ages. Mice were subjected to: (i) RMS from postnatal day (PND) 1 to 14 (RMS14); (ii) RMS from PND14 to 21 (RMS21); (iii) SMS on PND14 (SMS14); and (iv) SMS on PND21 (SMS21). Plasma corticosterone and c-Fos expression were examined on the final day in each experiment. The basal corticosterone levels in RMS14 and RMS21 were equal to those in respective age-matched controls. After the final separation, the levels were significantly increased and were comparable with those after SMS14 and SMS21, respectively. Histological analysis indicated that c-Fos expression significantly increased in many brain regions, including the paraventricular nucleus, prefrontal cortex, hippocampus, and basolateral and medial amygdale in both SMS14 and SMS21 mice. However, c-Fos expression in RMS14 mice significantly increased in many regions, whereas such increases were hardly seen in RMS21 mice. These results indicate that repeated early-life stress neither increases basal corticosterone, nor decreases the magnitude of the corticosterone response during the first three postnatal weeks, although desensitisation of c-Fos expression induced by repeated stress is changed during postnatal development.

IgG4-related ocular adnexal disease mimicking thyroid-associated orbitopathy

A 72-year-old man presented with bilateral eyelid swelling and redness. An orbital CT scan showed bilateral proptosis, extraocular muscle enlargement and swollen lacrimal glands, mimicking thyroid-associated orbitopathy (TAO) with Hashimoto's thyroiditis (HT). During the patient's clinical course, spontaneous remission of lung consolidation (35 × 26 mm) was seen. A diagnosis of IgG4-related disease (IgG4-RD) was made based on an elevated serum IgG4 level (1,020 mg/dL; normal, 4-108), predominance of IgG4-positive plasma cells (IgG4/IgG: 35/70 in HPF) in the lacrimal glands and typical features of Mikulicz's disease. This report provides a novel description of this unusual disease entity among HT, TAO and IgG4-RD.

Job stress and temperaments in female nurses

BACKGROUND

According to previous studies, temperament predicts a large share of the variance in job stress. It may be necessary for mental health practitioners to offer intervention strategies in accordance with individual temperament.

AIMS

To investigate the relationship between job stress and temperament among nurses in a general hospital and to provide insight into personality traits influencing their mental or physical health.

METHODS

A questionnaire survey of nurses in a general hospital. Work stress was measured using the Japanese version of the Effort-Reward Imbalance (ERI) scale. Temperament was assessed by a Japanese version of Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A). Hierarchical multiple regression analysis was used to determine the independent contribution of temperament to effort-reward ratio and over-commitment.

RESULTS

Response rate was 48% (326/685). Temperament predicted part of the variance of the four ERI ratios (effort-reward ratio 26%; effort-esteem ratio 27%; effort-promotion ratio 26%; and effort-security ratio 18%) and also of over-commitment (38%). Depressive temperament influenced all four ERI ratios and over-commitment. Anxious temperament influenced only over-commitment.

CONCLUSIONS

Nurses with depressive or anxious temperaments should be identified, monitored for signs of job stress and offered interventions to prevent adverse physical and mental effects.

Eating habits and colorectal cancer

In order to investigate the relation between the occurrence of colorectal cancer and food consumption in Hokkaido, Japan, etiological factors of colorectal cancer were investigated through an ecologic study using official food consumption and mortality statistics concerning colorectal cancer, and through a community-based case-control study. The ratio of 'animal foods' to 'plant foods' and that of 'animal protein' to 'plant protein' had a significant correlation with the mortality rate in colorectal cancer. The percentage of fat energy was much more contributory than the absolute amount of fat. Traditional Japanese foods tended to prevent while Western foods tended to promote colorectal cancer. Odds ratios for Japanese foods were low for colon cancer, and those for Western foods were high for rectum cancer. Relative amounts of foods are more contributory than their absolute amounts. An increase of colorectal cancer in Japanese people may be attributable to the increase in the relative amounts of Western foods. Reduction of the ratio of animal foods to plant foods (i.e., a reduction in relative amounts of Western foods or an increase in relative amounts of Japanese foods) may lend to the prevention of colorectal cancer.

Increased arterial stiffness is closely associated with hyperglycemia and improved by glycemic control in diabetic patients

Aims/Introduction

Although arteriosclerotic diseases have been reported to be frequently complicated by diabetes mellitus (DM), a detailed relationship between hyperglycemia and arterial stiffness has not been fully clarified. We investigated the influence of hyperglycemia on arterial stiffness using the cardio‐ankle vascular index (CAVI), which is a new method for estimating arterial stiffness.

Materials and Methods

CAVI values of 52 early‐staged DM patients (duration <5 years, no microangiopathies) were compared with those of 43 age‐matched non‐diabetic (NDM) subjects. The association between CAVI and clinical background factors was evaluated. The effect of glycemic improvement on CAVI was examined in 36 DM patients who were hospitalized for 2 weeks to treat hyperglycemia. CAVI and clinical parameters were measured twice during hospitalization and again after 8 weeks. Additionally, we measured CAVI before and 2 h after breakfast in five DM and five NDM subjects.

Results

The CAVI of DM patients was significantly higher than that of NDM subjects. Multiple regression analysis showed that neither hypertension, obesity nor dyslipidemia, but aging and hemoglobin A1c (HbA_1c) were significantly related to CAVI elevation. The CAVI, HbA_1c and total cholesterol (TC) had significantly improved. Improvement of CAVI was significantly associated with HbA_1c improvement. In contrast, no significant association was observed between the improvements of TC and CAVI. CAVI values before and after breakfast did not change significantly.

Conclusions

CAVI elevation seems to be a sensitive arteriosclerotic marker, which is closely associated with hyperglycemia and improved by glycemic control.

Numbness and paresthesia in bilateral toes and soles, and disproportional sweating restricted to face and trunk are suitable symptoms useful for the diagnosis of diabetic symmetric polyneuropathy

Aims/Introduction:  In order to diagnose diabetic symmetric polyneuropathy (DSPN) more simply and accurately, we identified symptoms that correlated with neurological functions and existed more frequently in diabetic than non‐diabetic subjects.

Materials and Methods:  The relationships between 10 symptoms (numbness or paresthesia in toe and sole, numbness in hand, pain in foot or hand, coldness in legs, painful leg cramp, dizziness on standing, sweating restricted to face/trunk and frequent constipation/diarrhea) and clinical background, defined as DSPN and cardiovascular autonomic neuropathy (CAN) by the criteria proposed in the statement of the American Diabetes Association, and seven quantitative nerve function data were evaluated in 593 diabetic patients in Wakayama Medical University Hospital (WMUH). Furthermore, the prevalence of various symptoms was examined by three questionnaires: a WMUH survey (999 diabetic outpatients), a Nationwide survey (1524 male diabetic outpatients under a primary‐care physician) and a Control survey (501 non‐diabetic subjects).

Results:  Bilateral ‘numbness in toe and sole’, ‘paresthesia in toe and sole’, ‘pain in foot’ and ‘sweating restricted to face/trunk’ were significantly associated with diabetes duration, retinopathy, probable and confirmed DSPN, possible and advanced CAN, and all or six nerve functions. Questionnaire surveys clarified that symptoms that are not rare (>15%) and more frequent in diabetic than non‐diabetic subjects were bilateral ‘numbness in toe and sole’, ‘paresthesia in toe and sole’, ‘coldness in legs’, ‘dizziness on standing’ and ‘sweating restricted to face/trunk’.

Conclusions:  Therefore, bilateral ‘numbness in toe and sole’, ‘paresthesia in toe and sole’ and ‘sweating restricted to face/trunk’ are suitable symptoms useful for the diagnosis of DSPN. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00124.x, 2011)

A case of liver abscess caused by Edwardsiella tarda

Edwardsiella tarda, a member of the Enterobacteriaceae family, is found in freshwater and marine environments. Extraintestinal infections of Edwardsiella tarda have been rarely reported. We describe a 70-year-old Japanese woman suffering from autoimmune hemolytic anemia, with liver abscess caused by Edwardsiella tarda. She had a history of cholecystectomy for gallbladder stone 10 years prior to this admission. She was successfully treated with percutaneous transhepatic abscess aspiration and meropenem. This is the first report of liver abscess caused by Edwardsiella tarda in Japan.

Effect of anti-oxidants, Ricetrienol and α-tocopherol, on adipocytokine abnormalities and fatty liver in Otsuka Long-Evans Tokushima Fatty diabetic rats

Introduction:  We investigated the effect of Ricetrienol, which is an anti‐oxidant extracted from rice bran, and α‐tocopherol on the adipocytokine abnormalities and fatty liver in Otsuka Long‐Evans Tokushima Fatty (OLETF) rats.

Materials and Methods:  A total of 18 OLETF rats were bred using a 30% sucrose solution (the diabetic group; DM), whereas another 18 OLETF rats were bred using ordinary water (the non‐diabetic obese group; OB) as drinking water, respectively. After the sucrose‐fed rats developed diabetes, all of the rats from the diabetic and obese groups were randomly divided into three groups. Then each group was fed either standard chow (DM‐S, OB‐S group), 0.05% Ricetrienol‐containing chow (DM‐R, OB‐R group) or 0.05%α‐tocopherol‐containing chow (DM‐A, OB‐A group), respectively. After 12 weeks of feeding, all the rats were killed. Plasma insulin, adiponectin, resistin and leptin were assayed by enzyme immunoassay. Histopathological findings of liver tissue were scored according to Brunt and Kleiner’s method, and triglyceride contents of the liver tissue were investigated.

Results:  Plasma adiponectin was significantly reduced in DM‐S compared with OB‐S, but it had significantly increased in DM‐R and DM‐A as opposed to DM‐S. Plasma resistin showed a significant increase in DM‐S compared with OB‐S, but it was significantly reduced in DM‐A than in DM‐S. Though the triglyceride contents of liver tissue significantly increased in DM‐S as opposed to OB‐S, they were significantly reduced in DM‐R compared with DM‐S. Histopathological scores were significantly higher in DM‐S than OB‐S.

Conclusions:  The present study shows that Ricetrienol might prevent adipocytokine abnormalities and fatty liver in OLETF diabetic rats. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00090.x, 2011)

Insulin gene mutations and diabetes

Some mutations of the insulin gene cause hyperinsulinemia or hyperproinsulinemia. Replacement of biologically important amino acid leads to defective receptor binding, longer half-life and hyperinsulinemia. Three mutant insulins have been identified: (i) insulin Chicago (F49L or PheB25Leu); (ii) insulin Los Angeles (F48S or PheB24Ser); (iii) and insulin Wakayama (V92L or ValA3Leu). Replacement of amino acid is necessary for proinsulin processing results in hyperproinsulinemia. Four types have been identified: (i) proinsulin Providence (H34D); (ii) proinsulin Tokyo (R89H); (iii) proinsulin Kyoto (R89L); and (iv) proinsulin Oxford (R89P). Three of these are processing site mutations. The mutation of proinsulin Providence, in contrast, is thought to cause sorting abnormality. Compared with normal proinsulin, a significant amount of proinsulin Providence enters the constitutive pathway where processing does not occur. These insulin gene mutations with hyper(pro)insulinemia were very rare, showed only mild diabetes or glucose intolerance, and hyper(pro)insulinemia was the key for their diagnosis. However, this situation changed dramatically after the identification of insulin gene mutations as a cause of neonatal diabetes. This class of insulin gene mutations does not show hyper(pro)insulinemia. Mutations at the cysteine residue or creating a new cysteine will disturb the correct disulfide bonding and proper conformation, and finally will lead to misfolded proinsulin accumulation, endoplasmic reticulum stress and apoptosis of pancreatic β-cells. Maturity-onset diabetes of the young (MODY) or an autoantibody-negative type 1-like phenotype has also been reported. Very recently, recessive mutations with reduced insulin biosynthesis have been reported. The importance of insulin gene mutation in the pathogenesis of diabetes will increase a great deal and give us a new understanding of β-cell biology and diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00100.x, 2011).

Expression and localization of vascular endothelial growth factor in normal abdominal aorta and abdominal aortic aneurysm

AIM

The genesis of abdominal aortic aneurysms is associated with remodeling of the vascular wall by angiogenesis as well as proteolysis. Vascular endothelial growth factor (VEGF) is known to be a regulator of angiogenesis and to simultaneously stimulate elastolytic proteinases. We analyzed the expression and localization of VEGF in human abdominal aortic aneurysms compared to normal human aorta

METHODS

Eighteen infrarenal aortic aneurysm samples were collected at the time of abdominal aortic aneurysm surgery, while nine normal aortic samples were obtained from autopsy specimens. Immunohistochemical staining was performed to detect VEGF. Immunoenzyme or immunofluorescent double staining was also used to identify those cells presenting VEGF.

RESULTS

VEGF was expressed in 18 (100%) of the 18 abdominal aortic aneurysm samples, while 0 (0%) in the 9 normal abdominal aorta samples. Of the 18 samples of aneurysms, all 18 displayed positive VEGF immunostaining in macrophages, 12 in smooth muscle cells (SMCs), and 9 in endothelial cells (ECs).

CONCLUSION

Our study clearly demonstrated the expression of VEGF in ECs, and SMCs, and macrophages of abdominal aortic aneurysms as well as its absence in those cells of normal abdominal aorta, suggesting that VEGF may play an important role in aneurysm formation via its direct and/or indirect actions.

Ghrelin inhibits insulin secretion through the AMPK-UCP2 pathway in beta cells

Ghrelin inhibits insulin secretion partly via induction of IA-2beta. However, the orexigenic effect of ghrelin is mediated by the AMP-activated protein kinase (AMPK)-uncoupling protein 2 (UCP2) pathway. Here, we demonstrate that ghrelin's inhibitory effect on insulin secretion also occurs through the AMPK-UCP2 pathway. Ghrelin increased AMPK phosphorylation and UCP2 mRNA expression in MIN6 insulinoma cells. Overexpression or downregulation of UCP2 attenuated or enhanced insulin secretion, respectively. Furthermore, AMPK activator had a similar effect to ghrelin on UCP2 and insulin secretion in MIN6 cells. In conclusion, ghrelin's inhibitory effect on insulin secretion is partly mediated by the AMPK-UCP2 pathway, which is independent of the IA-2beta pathway.

Truncal pruritus of unknown origin may be a symptom of diabetic polyneuropathy

OBJECTIVE

Our goal was to ascertain the prevalence of pruritus in diabetic and nondiabetic subjects and the relevance of symptoms, signs, and nerve functions of diabetic polyneuropathy (DPN) of pruritus.

RESEARCH DESIGN AND METHODS

A large-scale survey of 2,656 diabetic outpatients and 499 nondiabetic subjects was performed. In diabetic subjects, the relationship between pruritus and age, sex, diabetic duration, A1C, Achilles tendon reflex (ATR), and abnormal sensation in legs was evaluated. In 105 diabetic subjects, nerve conduction studies, quantitative vibratory threshold (QVT), heart rate variability, and a fall of systolic blood pressure at a head-up tilt test (DeltaBP) were performed, and the relationships between pruritus and nerve functions were evaluated.

RESULTS

Although the prevalence of truncal pruritus of unknown origin (TPUO) in diabetic subjects was significantly higher than that in age-matched nondiabetic subjects (11.3 vs. 2.9%, P = 0.0001), the prevalence of other pruritus was not different between the two groups. Multiple logistic regression analysis revealed that abnormal sensation and ATR areflexia were independent risk factors for TPUO in age, sex, duration of diabetes, and A1C. DeltaBP in diabetic subjects with TPUO was significantly impaired compared with that in those without TPUO. Larger DeltaBP was identified as a significant risk factor of TPUO independent of other nerve dysfunctions by multiple logistic regression analysis.

CONCLUSIONS

TPUO is significantly more frequent in diabetic than in nondiabetic individuals. TPUO is significantly associated with symptoms and signs of DPN, including impaired blood pressure response in a head-up tilt test. TPUO, therefore, might be a newly recognized symptom of DPN.

Effort-reward imbalance and depressive state in nurses

BACKGROUND

The mental health of nurses is an important issue.

AIMS

To examine relationships between effort-reward imbalance (ERI) and depression and anxiety in nurses of a Japanese general hospital.

METHODS

A self-report survey was conducted among 406 nurses. Work stress was measured using a Japanese version of the ERI scale. Depression and anxiety were assessed by an item of the QOL-26. Logistic regression analysis was used to determine the independent contribution of the effort-reward ratios or overcommitment to the depressive state.

RESULTS

Both higher effort-money ratio and higher overcommitment significantly correlated with the depressive state (OR: 2.75; 95% CI: 1.34-5.66 and OR: 1.27; 95% CI: 1.15-1.41, respectively).

CONCLUSIONS

These findings suggest that in addition to effort-money ratio, overcommitment at work is an especially important issue that may be able to be managed in health promotion services for nurses in general hospitals.

SUMO4 Met55Val polymorphism is associated with coronary heart disease in Japanese type 2 diabetes individuals

The Met55Val polymorphism in the small ubiquitin-like modifier 4 (SUMO4) gene has been associated with susceptibility not only to type 1 diabetes, but also to type 2 diabetes and diabetic nephropathy. We tried to confirm the association with susceptibility to type 2 diabetes and to investigate its role in diabetic vascular complications. The polymorphism was genotyped in two independent Japanese samples (Wakayama and Tokyo) by the TaqMan method. Susceptibility to type 2 diabetes and prevalence of diabetic vascular complications (coronary heart disease, cerebral infarction, retinopathy, and nephropathy) were evaluated by case-control study and multivariate logistic regression analysis, respectively. There were no significant differences in the frequency of alleles or genotypes between patients and controls. The Val allele, however, was associated with higher prevalence of coronary heart disease in patients in both groups (Wakayama, n=423, odds ratio, 1.64; 95% confidence interval, 1.02-2.64; P=0.041; Tokyo, n=451, odds ratio, 1.58; 95% CI, 1.07-2.34; P=0.021, in an additive model, respectively). No significant associations were observed with other diabetic vascular complications. Although association of the polymorphism with susceptibility to type 2 diabetes or nephropathy was not replicated, an association of the polymorphism with risk of coronary heart disease in type 2 diabetes is suggested.

Coenzyme Q10 protects retinal cells against oxidative stress in vitro and in vivo

PURPOSE

To investigate the neuroprotective effects of coenzyme Q10 and/or a vitamin E analogue on retinal damage both in vitro and in vivo.

METHODS

We employed cultured retinal ganglion cells (RGC-5, a rat ganglion cell-line transformed using E1A virus) in vitro. Cell damage was induced by 24-h hydrogen peroxide (H2O2) exposure, and cell viability was measured using tetrazolium salt (WST-8). To examine the retinal damage induced by intravitreal N-methyl-d-aspartate (NMDA) injection in mice in vivo, coenzyme Q10 at 10 mg/kg with or without alpha-tocopherol at 10 mg/kg was administered orally (p.o.) each day for 14 days, with NMDA being intravitreally injected on day 7 of this course.

RESULTS

In RGC-5, a combination of coenzyme Q10 and trolox, a water-soluble vitamin E analogue (a derivative of alpha-tocopherol), prevented cell damage more effectively than either agent alone. Coenzyme Q10 and alpha-tocopherol (separately or together) reduced the retinal damage, number of TUNEL-positive cells in the ganglion cell layer (GCL), and 4-hydroxyl-2-nonenal (4-HNE) expression induced by NMDA in mice in vivo.

CONCLUSIONS

Coenzyme Q10 and/or these vitamin E analogues exert neuroprotective effects against retinal damage both in vitro and in vivo.

Steroid receptor signalling in the brain--lessons learned from molecular imaging

Studies with green fluorescent protein (GFP) have revealed the subcellular distribution of many steroid hormone receptors to be much more dynamic than previously thought. Fluorescence resonance energy transfer (FRET) and fluorescence recovery after photobleaching (FRAP) are powerful techniques with which to examine protein-protein interaction and the mobility of tagged proteins, respectively. FRET analysis revealed that steroid treatment (with corticosterone or testosterone) induces direct interaction of the glucocorticoid receptor (GR) and importin alpha in the cytoplasm and that, shortly after nuclear entry, the GR detaches from importin alpha. The mineralocorticoid receptor (MR) and androgen receptor (AR) show the same trafficking. Upon oestradiol treatment, ERalpha and ERbeta in the same cell are relocalised to form a discrete pattern and are localised in the same discrete cluster (subnuclear foci). FRAP analysis showed that nuclear ERalpha and ERbeta are most dynamic and mobile in the absence of the ligand, and that mobility decreases slightly after ligand treatment. Genomic as well as non-genomic actions of steroid hormones influence the cellular function of target tissues spacio-temporally.

Cardio-ankle vascular index measures arterial wall stiffness independent of blood pressure

Although brachial-ankle pulse wave velocity (baPWV) is a non-invasive method of detecting arteriosclerosis, it is affected by changes in blood pressure (BP). Cardio-ankle vascular index (CAVI) is a new method for estimating arteriosclerosis, and it has been reported to be less influenced by BP. We investigated the influence of BP changes on CAVI and the correlation of CAVI to clinical factors and carotid arteriosclerosis. CAVI and baPWV in 35 non-diabetic and 33 diabetic subjects were measured in increased BP (after stair climbing) and rested BP (after 10min of rest). Intima-media thickness (IMT) of carotid arteries was measured by ultrasoundsonography. We achieved the following results: CAVI did not show a significant change with a change in BP in both non-diabetic and diabetic subjects. On the contrary, baPWV was significantly influenced by BP changes. Carotid artery IMT had a significant positive correlation with CAVI and baPWV. Multiple regression analysis revealed that significant risk factors of high baPWV were age and systolic BP. On the contrary, significant risk factors of high CAVI were age and hemoglobin A1c, while systolic BP was not relevant. Our findings suggest that CAVI is independent of BP and useful as an indicator of early arteriosclerosis in diabetic subjects.

Mutations in the beta1 adrenergic receptor gene and massive obesity in Japanese

Catecholamines strongly promote lipolysis and thermogenesis, and play a central role in the regulation of body fat content. The beta1 adrenergic receptor (BAR-1) is a major mediator of catecholamine-induced lipolysis and thermogenesis. To explore whether mutations in the BAR-1 gene contribute to morbid obesity in Japanese, we scanned for mutations in the coding sequence of the gene in 50 morbid obese [body mass index (BMI)>==35.0kg/m(2); 99.7th percentile] Japanese subjects. Direct DNA sequencing was performed following polymerase chain reaction (PCR) amplification. Two common polymorphisms, Gly49Arg and Arg389Ser, were detected in these subjects. The frequencies of these polymorphisms, as determined by PCR-restriction fragment length polymorphism (RFLP) analysis, showed no significant difference between 180 severely obese subjects (BMI>==30.0kg/m(2); 97th percentile) and 132 control (BMI<25.0kg/m(2)) subjects. This study represents the first investigations of genetic variations of BAR-1 in relationship to morbid obesity and suggests mutations in the BAR-1 coding sequence is not likely a major cause of morbid obesity at least in Japanese.

A mitochondrial DNA variant at position 16189 is associated with type 2 diabetes mellitus in Asians

AIMS/HYPOTHESIS

This multinational study was conducted to investigate the association between a mitochondrial DNA (mtDNA) T16189C polymorphism and type 2 diabetes in Asians. The mtDNA 16189C variant has been reported to be associated with insulin resistance and type 2 diabetes. However, a recent meta-analysis concluded that it is negatively associated with type 2 diabetes in Europids. Since the phenotype of an mtDNA mutant may be influenced by environmental factors and ethnic differences in the nuclear and mitochondrial genomes, we investigated the association between the 16189C variant and type 2 diabetes in Asians.

METHODS

The presence of the mtDNA 16189C variant was determined in 2,469 patients with type 2 diabetes and 1,205 non-diabetic individuals from Korea, Japan, Taiwan, Hong Kong and China. An additional meta-analysis including previously published Asian studies was performed. Since mtDNA nucleotide position 16189 is very close to the mtDNA origin of replication, we performed DNA-linked affinity chromatography and reverse-phase liquid chromatography/tandem mass spectrometry and chromatin immunoprecipitation to identify protein bound to the 16189 region.

RESULTS

Analysis of participants from five Asian countries confirmed the association between the 16189C variant and type 2 diabetes [odds ratio (OR) 1.256, 95% CI 1.08-1.46, p=0.003]. Inclusion of data from three previously published Asian studies (type 2 diabetes n=3,283, controls n=2,176) in a meta-analysis showed similar results (OR 1.335, 95% CI 1.18-1.51, p=0.000003). Mitochondrial single-stranded DNA-binding protein (mtSSB) was identified as a candidate protein bound to the 16189 region. Chromatin immunoprecipitation in cybrid cells showed that mtSSB has a lower binding affinity for the 16189C variant than the wild-type sequence.

CONCLUSIONS/INTERPRETATION

The mtDNA 16189C variant is associated with an increased risk of type 2 diabetes in Asians.

Last resort for renal transplant recipients, 'restored kidneys' from living donors/patients

Because of the grave shortage of deceased kidney allografts in Japan, we have embarked on a new source of organs, 'Restored kidneys' from living patients. From January 1991 through September 2006, 42 kidneys (eight benign pathology, eight small renal cancers, eight ureteral cancers, six aneurysms, eight severe nephrotic syndrome from four patients and four ureteral stenosis) were obtained from 38 patients/donors after extensive discussion of treatment modalities and risks. All patients/donors agreed to undergo total nephrectomy. The lesions were removed/repaired ex vivo on the back table, then transplanted. All recipients were notified of all possible risks including donor disease recurrence. One, 5 and 10-year patient survival rates of restored transplant patients were 92.9%, 79.3% and 63.8%, respectively. One, 5 and 10-year graft survival rates of restored kidney transplant patients were 78.6%, 51.8% and 42.7%, respectively. There were no recurrences of small renal cell carcinomas. There was one recurrence of ureteral cancer in the transplanted kidney 15 months after operation. In countries where deceased donors are scarce, such as Japan, the restored kidneys can be a last resort for renal allografts.

Polymorphisms in the IDE-KIF11-HHEX gene locus are reproducibly associated with type 2 diabetes in a Japanese population

CONTEXT

A genome-wide association study in the French population has detected that novel single-nucleotide polymorphisms (SNPs) in the IDE-KIF11-HHEX gene locus and the SLC30A8 gene locus are associated with susceptibility to type 2 diabetes.

OBJECTIVE

We investigated whether SNPs in these loci were associated with type 2 diabetes in Japanese.

DESIGN

Two SNPs, rs7923837 and rs1111875, in the IDE-KIF11-HHEX gene locus and one SNP, rs13266634, in the SLC30A8 gene locus were genotyped in Japanese type 2 diabetic patients (n = 405) and in nondiabetic control subjects (n = 340) using the TaqMan genotyping assay system.

RESULTS

The G allele of rs7923837 was associated with type 2 diabetes [odds ratio 1.66, 95% confidence interval (CI) 1.28-2.15; P = 0.00014], following the same tendency as in the French population of the previous report. Heterozygous and homozygous carriers of the risk allele had odds ratios of 1.57 (95% CI 1.15-2.16; P = 0.0050) and 3.16 (95% CI 1.40-7.16; P = 0.0038) relative to noncarriers. Although the G allele was a major allele (66.5%) in the French population, it was a minor allele (23.8%) in Japanese. The G allele of rs1111875 was also associated with type 2 diabetes (odds ratio 1.42, 95% CI 1.13-1.78; P = 0.0024). Heterozygous and homozygous carriers of the risk allele had odds ratios of 1.31 (95% CI 0.97-1.77; P = 0.0810) and 2.40 (95% CI 1.34-4.32; P = 0.0028) relative to noncarriers. A significant association with type 2 diabetes was not observed for rs13266634.

CONCLUSIONS

Polymorphisms in the IDE-KIF11-HHEX gene locus are associated with susceptibility to type 2 diabetes across the boundary of race.

Tumor-induced hypophosphatemic osteomalacia diagnosed by the combinatory procedures of magnetic resonance imaging and venous sampling for FGF23

This report describes a 37-year-old man with tumor-induced osteomalacia (TIO). The patient had hypophosphatemia and elevated fibroblast growth factor 23 (FGF23) in the peripheral blood. Magnetic resonance imaging detected an abnormal mass in the left greater trochanter. Venous sampling revealed a significantly higher level of FGF23 in the left common iliac vein (proximal to the tumor), verifying that the tumor is responsible for TIO. The serum level of FGF23 decreased and symptoms improved after removal of the tumor. The combined diagnostic procedures of MRI and venous sampling for FGF23 effectively detected the tumor responsible for TIO.

Ferulic acid prevents pathological and functional abnormalities of the kidney in Otsuka Long-Evans Tokushima Fatty diabetic rats

We investigated the preventive effects of ferulic acid (FA) and alpha-tocopherol (AT) on the progression of diabetic nephropathy. Otsuka Long-Evans Tokushima Fatty (OLETF) and Long-Evans Tokushima Otsuka (LETO) rats were used as type 2 diabetes and non-diabetes models, respectively. Two-thirds of the OLETF rats were fed 0.2% FA-containing or 0.5% AT-containing chow. Diabetic nephropathy was assessed based on urinary protein excretion and pathological changes which were scored based on the percentages of extracellular matrix area in the glomerular area. Furthermore, renal messenger RNA (mRNA) expression of intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2) and transforming growth factor-beta1 (TGF-beta1) was quantified by real-time polymerase chain reaction. After 12 weeks of FA- or AT-supplementation, urinary protein in untreated-OLETF group was significantly higher than that in LETO group, thus FA-supplementation significantly decreased urinary protein excretion. Pathological scores in FA-supplemented group were significantly lower than those in untreated OLETF group. Supplementation with either FA or AT significantly prevented the elevation of TGF-beta1 mRNA expression caused by diabetes. Treatment with neither FA nor AT had a significant effect on COX-2 or ICAM-1 mRNA expressions. We have demonstrated the preventative effects of FA on diabetic nephropathy via suppression of TGF-beta1 upregulation, furthermore FA may be more potent than AT.

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. Genotyping of variants identified was done by PCR-restriction fragment length polymorphism analysis.

RESULTS

Eight sequence differences were identified. Two novel variations (R164W and IVS7-1G>A) were found in two different probands. Neither was found in the 74 nondiabetic controls and additional 270 healthy subjects of Thai origin. R164W segregated with diabetes in the family of the proband and in vitro studies showed that it impairs the repressor activity of PAX4 on the insulin and glucagon promoters. The remaining six variants were previously described and observed in both groups. One of them, R192H, was three times more frequent in MODY probands than in 342 nondiabetic controls (minor allele frequency = 0.196 vs. 0.064; P < 0.00001). The same variant was associated with a younger age at diagnosis among 254 Thai subjects with adult-onset type 2 diabetes (44.6 +/- 15 vs. 49.7 +/- 11 yr; P = 0.048).

CONCLUSIONS

We have identified two possible pathogenic mutations of PAX4, R164W, and IVS7-1G>A. For one of these, we have shown evidence of segregation with diabetes and a functional impact on PAX4 activity. Single-nucleotide polymorphism R192H might influence the age at onset of diabetes.

Direct visualization of glucocorticoid receptor positive cells in the hippocampal regions using green fluorescent protein transgenic mice

The hippocampal formation is a plastic brain structure important for certain types of learning and memory, and also vulnerable to the effects of stress and trauma. Since hippocampal neurons express high levels of corticosteroid receptor, the morphological changes, including alterations in the size of soma, and the length and number of neurites and spines, in response to glucocorticoids released as a result of stress are intriguing. In order to highlight the morphology of neurons that express glucocorticoid receptor (GR), we have generated a transgenic mouse line expressing green fluorescent protein (GFP) under the control of the GR promoter. We found strong green fluorescence in the pyramidal cell layer of the CA1 and CA2 regions and the granule cell layer of the dentate gyrus of the hippocampus in brain sections of the transgenic mice. GFP fluorescence was observed not only in somas, but also in neurites including both dendrites and axons. In dissociated culture, we also observed GFP fluorescence in the soma, neurites including both dendrites and axons, and dendritic spines. Microtubule-associated protein 2 immunopositive pyramidal-shaped neurons clearly showed two different populations, GFP positive and GFP negative neurons. These results indicate that this transgenic mouse line should be useful for live imaging of neuronal structure in animals as well as GR-positive cultured cells using GFP as a specific indicator.

Expression and production of aberrant PAX5 with deletion of exon 8 in B-lineage acute lymphoblastic leukaemia of children

Summary We investigated PAX5 expression in childhood B-lineage acute lymphoblastic leukaemia (ALL). Seven of 21 children with B-lineage ALL had multiple PAX5 variants, while 14 children and healthy controls showed full-length (FL) and one variant PAX5. By Western blotting, healthy controls displayed Pax5-FL, while one short Pax5, derived from the deletion of exon 8 (Pax5-DeltaE8) was produced in 90% of ALL samples, as well as in ALL cell lines. PAX5-DeltaE8 lacked more than 50% of the transactivation domain, indicating that aberrant Pax5 production might lead to the arrest of B-cell differentiation, contributing to the pathogenesis of B-lineage ALL.

Peripheral nerve functions may deteriorate parallel to the progression of microangiopathy in diabetic patients

Our aim was to obtain information to help in the early detection of impaired nerve function and to assess the severity of diabetic symmetric polyneuropathy (DPN). Various somatic and autonomic nerve functions in 40 diabetics and 20 age-matched healthy volunteers were evaluated using six objective examinations: nerve conduction study, quantitative vibratory perception threshold, heart rate variability, Valsalva test, head-up tilt and quantitative sudomotor axonal reflex test (QSART). The diabetics were divided into three groups according to the severity of their microangiopathy. The nerve function data and level of impairment were compared between a healthy control and three diabetic groups. The relationships between nerve function data and clinical background were also examined using multivariate analysis. Results were as follows: (1) all nerve dysfunctions seemed to develop parallel to the progression of microangiopathy, (2) reduced nerve conduction velocity and elevated vibratory perception thresholds in the feet might be early detectable signs of DPN, (3) vasomotor and sudomotor sympathetic functions and cardiovagal functions seemed to deteriorate with the appearance of microangiopathy, (4) lowered compound muscle action potential seemed to appear at the advanced microangiopathic condition, (5) hypohydrosis was closely related to diabetic foot ulcers. In conclusion, nerve dysfunction in diabetics might generally progress with microangiopathy from somatic sensory nerve dysfunction to autonomic nerve dysfunction and then to somatic motor nerve dysfunction. Sympathetic sudomotor dysfunction might be a sensitive predictor of diabetic foot ulcer.

Uncoupling protein 2 promoter polymorphism -866G/A affects peripheral nerve dysfunction in Japanese type 2 diabetic patients

OBJECTIVE

To determine genetic predispositions for diabetic polyneuropathy, we investigated the relationship between the -866G/A polymorphism of uncoupling protein (UCP) 2 and neurological manifestations in 197 type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

We first examined whether UCP2 mRNA had been expressed in the dorsal root ganglion (DRG) in four Long-Evans Tokushima Otsuka rats using RT-PCR and electrophoresis. Genotyping of UCP2 promoter polymorphism -866G/A was then performed in 197 unrelated Japanese type 2 diabetic patients, who were subjected to nerve conduction, quantitative vibratory perception, head-up tilt, and heart rate variability tests, by PCR restriction fragment-length polymorphism. The relationships between UCP2 genotype and various nerve functions were analyzed by uni- and multivariable analysis.

RESULTS

Expression of UCP2 mRNA was confirmed in rat DRG. Multiple regression analysis clarified the hypothesis that the G/A + A/A genotype was significantly related to decreased motor nerve conduction velocity and impaired blood pressure maintenance on the head-up tilt test. Multiple logistic regression analysis revealed that the G/A + A/A genotypes are a significant risk factor for sensory nerve conduction slowing and orthostatic hypotension.

CONCLUSIONS

UCP2 promoter gene polymorphism -866 G/A was significantly associated with nerve conduction slowing and vasomotor sympathetic functions. These findings suggest that the higher UCP2 activity related to the A allele has an energy-depleting effect on peripheral nerve function in type 2 diabetic patients.

Extracellular superoxide dismutase gene polymorphism is associated with insulin resistance and the susceptibility to type 2 diabetes

Oxidative stress has been implicated in pancreatic beta-cell damage, insulin resistance and vascular function in diabetic patients and the dysfunction of antioxidant enzymes may be associated with the pathogenesis of diabetes. Extracellular superoxide dismutase (EC-SOD) is found in the extracellular matrix of tissues and the major scavenger of superoxide radical. To investigate the role of genetic variability for the pathogenesis of type 2 diabetes, we scanned the protein coding exon and flanking introns of EC-SOD gene for mutation in Japanese type 2 diabetic patients. We identified two missense mutations, Ala40Thr (GCG-->ACG) and Arg213Gly (CGG-->GGG), and a silent mutation, Leu53Leu (CTG-->TTG). For one of these variants, the Ala40Thr polymorphism, the frequency of Thr allele and the number of subjects with Thr allele (Ala/Thr+Thr/Thr) were higher in type 2 diabetic patients (n=205) than those in non-diabetic subjects (n=220) (33.2% versus 24.1%, p=0.003 and 55.6% versus 42.7%, p=0.008, respectively). The patients with Thr allele also showed earlier age at diagnosis of diabetes (42.2+/-7.8 years versus 44.4+/-6.9 years, p=0.037) and higher prevalence of hypertension (53.5% versus 38.5%, p=0.032) than those without the allele. Insulin sensitivity, furthermore, was evaluated in 71 type 2 diabetic patients with short insulin tolerance test (SITT). The patients with Thr allele showed lower insulin sensitivity (Kitt value of SITT) than those without the allele (1.78+/-0.78%/min versus 2.33+/-1.02%/min, p=0.012), although no significant differences in other clinical and biochemical characteristics were observed between two groups. These results suggest that the genetic variant of EC-SOD gene is associated with insulin resistance and the susceptibility to type 2 diabetes.

IA-2beta, but not IA-2, is induced by ghrelin and inhibits glucose-stimulated insulin secretion

Ghrelin is a newly discovered peptide and an endogenous ligand for growth hormone (GH) secretagogue (GHS) receptor. It has been shown to possess various central and peripheral effects, including GH secretion, food intake, and gastric and cardiac effects. Ghrelin and the GHS receptor are expressed also in pancreatic islets. We have identified several ghrelin-induced genes by PCR-select subtraction methods, among which is a beta-cell autoantigen for type 1 diabetes, IA-2beta. Administration of ghrelin increased IA-2beta mRNA in mouse brain, pancreas, and insulinoma cell lines (MIN6 and betaTC3). However, the expression of IA-2, another structurally related beta-cell autoantigen, was not induced by ghrelin. Administration of ghrelin or overexpression of IA-2beta, but not overexpression of IA-2, inhibited glucose-stimulated insulin secretion in MIN6 insulinoma cells and, moreover, inhibition of IA-2beta expression by the RNA interference technique ameliorated ghrelin's inhibitory effects on glucose-stimulated insulin secretion. These findings strongly suggest that inhibitory effects of ghrelin on glucose-stimulated insulin secretion are at least partly due to increased expression of IA-2beta induced by ghrelin. Our data demonstrate the link among ghrelin, IA-2beta, and glucose-stimulated insulin secretion.

A functional variant in the human betacellulin gene promoter is associated with type 2 diabetes

Betacellulin (BTC) plays an important role in differentiation, growth, and antiapoptosis of pancreatic beta-cells. We characterized about 2.3 kb of the 5'-flanking region of human BTC gene and identified six polymorphisms (-2159A>G, -1449G>A, -1388C>T, -279C>A, -233G>C, and -226A>G). The G allele in the -226A>G polymorphism was more frequent in type 2 diabetic patients (n = 250) than in nondiabetic subjects (n = 254) (35.6% vs. 27.8%, P = 0.007), and the -2159G, -1449A, and -1388T alleles were in complete linkage disequilibrium with the -226G allele. The frequencies of the -279A and -233C alleles were low (7.0 and 2.0% in diabetic patients), and no significant differences were observed. In the diabetic group, insulin secretion ability, assessed by the serum C-peptide response to intravenous glucagon stimulation, was lower in patients with the -226G allele (G/G, 2.96 +/- 0.16 ng/ml; G/A, 3.65 +/- 0.18 ng/ml; A/A, 3.99 +/- 0.16 ng/ml at 5 min after stimulation; P = 0.008). Furthermore, in vitro functional analyses indicated that both the -226G and the -233C alleles caused an approximately 50% decrease in the promoter activity, but no effects of the -2159A>G, -1449G>A, -1388C>T, and -279C>A polymorphisms were observed. These results suggest that the -226A/G polymorphism of the BTC gene may contribute to the development of diabetes.

Increased gene expression of antioxidant enzymes in KKAy diabetic mice but not in STZ diabetic mice

Oxidative stress and the gene expression at the transcriptional level of antioxidant enzymes were investigated in two models of diabetes in mice. We used KKAy mice as a model of obese insulin-resistant diabetes, and streptozotocin-induced diabetic mice (STZ mice) as a model of insulin-deficient diabetes. C57BL mice and saline-injected ICR mice were used as the respective non-diabetic controls. To assess oxidative damage, plasma malonedialdehyde (MDA), urine 8-isoprostane and 8-hydroxy deoxyguanosine (8-OHdG) were measured. The mRNA expression of antioxidant enzymes, superoxide dismutase 1 (SOD-1) and glutathione peroxidase 1 (GPx-1) in the kidney and heart were quantified using a real-time polymerase chain reaction. The KKAy mice demonstrated moderate hyperglycemia and hyperlipidemia, and the STZ mice showed severe hyperglycemia and hypolipidemia. The KKAy mice, but not the STZ mice, showed elevated plasma MDA relative to the non-diabetic controls. Urine 8-isoprostane and 8-OHdG in both diabetic mouse groups increased significantly. The urine oxidative stress markers in the severely hyperglycemic STZ mice were higher than those in the moderately hyperglycemic KKAy mice. Although GPx-1 and SOD-1 showed elevated mRNA expression in the KKAy mice in the kidney and heart, in the STZ mice they did not increase compared to the controls. The compensatory up-regulation of the mRNA expression of antioxidant enzymes may be impaired in the insulin-deficient severely hyperglycemic state.

Molecular scanning of the betacellulin gene for mutations in type 2 diabetic patients

Betacellulin (BTC), a member of the epidermal growth factor (EGF) family, is an important factor in the growth and/or differentiation of pancreatic beta cells. In this point of view, we determined the transcriptional start site of the human BTC gene and screened the protein-coding region for mutations. The transcriptional start site was located 347 bp upstream from the translational initiation codon. After screening the protein coding exons (exons 1-5), we identified two novel missense mutations, Cys (TGC) to Gly (GGC) at codon 7 (C7G) and Leu (TTG) to Met (ATG) at codon 124 (L124M), and a single nucleotide substitution (-31c/t) in the intron 2. The C7G was located in the signal peptide and the L124M in the transmembrane domain and this Leu at codon 124 was conserved among human, bovine, rat, and mouse. The frequencies of these variants, however, were similar between type 2 diabetic patients (n = 228) and non-diabetic control subjects (n = 170). These data suggest that genetic variations in the protein-coding region of the human BTC gene are unlikely to be a major contributor to development of type 2 diabetes.

A case of novel de novo paired box gene 6 (PAX6) mutation with early-onset diabetes mellitus and aniridia

BACKGROUND

Paired box gene 6 (PAX6) is a transcription factor involved in eye development. Mutations of PAX6 cause congenital eye anomalies, such as aniridia. PAX6 is also involved in the development of the endocrine pancreas, and reported to be a genetic factor common to aniridia and glucose intolerance, although the latter is usually mild. Here, we describe a case of PAX6 mutation with early-onset diabetes mellitus.

CASE REPORT

A 27-year-old woman was referred to our clinic. She was diagnosed having diabetes at the age of 15 with negative glutamic acid decarboxylase (GAD) antibody. Insulin treatment was started at age 24. Because she had aniridia, PAX6 gene mutation was investigated and a heterozygous 2-bp deletion (c.402del2) was identified. Her parents did not have aniridia and PAX6 mutations. Heterozygous PAX6 mutation may cause glucose intolerance. However, cases of early-onset diabetes mellitus have not been reported. Her parents did not have diabetes, but their insulinogenic indices were low (0.25 and 0.3, respectively). We thought her early-onset diabetes was partly as a result of PAX6 mutation and partly because of an unknown insulin secretory defect inherited from her parents. We could not find any mutations in HNF-1alpha, -1beta, -4alpha, IPF-1, ISL-1, BEAT2/NeuroD1, PAX4, and amylin genes.

CONCLUSIONS

We report a case of PAX6 gene mutation with early-onset diabetes mellitus and aniridia. Low insulin secretory capacity in her parents suggested that her insulin secretory defect is as a result of not only PAX6 mutation but other genetic factors inherited from her parents.