The collembolan Sinella dubiosa produces eicosapentaenoic acid

n-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA), are essential nutrients for vertebrate development and physiology. Microorganisms, such as microalgae, produce n-3 PUFAs that are transferred to higher predators in the aquatic food web. However, recent studies have demonstrated that various aquatic invertebrates possess the biosynthetic enzymes required for n-3 PUFA production, raising the possibility that n-3 PUFAs are also produced in certain aquatic invertebrates. In contrast to aquatic invertebrates, it remains unclear whether and how PUFAs are produced in terrestrial invertebrates, including collembolans, one of the most widespread microarthropods in soil ecosystems. In this study, we investigated the biosynthetic capacity of n-3 PUFAs in litter-dwelling Collembola, Sinella dubiosa. We detected EPA in Sinella dubiosa reared on Brewer's yeast, which produced only saturated and monounsaturated fatty acids. Furthermore, metabolic analysis using isotope-labeled fatty acids revealed that oleic, linolenic, and arachidonic acids were metabolized to EPA in Sinella dubiosa. Given that collembolans are food for predatory arthropods and their nutrients are transferred to higher predatory vertebrates in the soil food web, we propose that Collembola serve as an EPA source in soil ecosystems.

Bioproduction of n-3 polyunsaturated fatty acids by nematode fatty acid desaturases and elongase in Drosophila melanogaster

n-3 polyunsaturated fatty acids (n-3 PUFAs), including α-linolenic acid and eicosapentaenoic acid (EPA), are essential nutrients for vertebrates including humans. Vertebrates are n-3 PUFA-auxotrophic; hence, dietary intake of n-3 PUFAs is required for their normal physiology and development. Although fish meal and oil have been utilized as primary sources of n-3 PUFAs by humans and aquaculture, these traditional n-3 PUFA sources are expected to be exhausted because of the increasing consumption requirements of humans. Hence, it is necessary to establish alternative n-3 PUFA sources to reduce the gap between the supply and demand of n-3 PUFAs. Here, we investigated whether insects, which are considered as a novel source of essential nutrients, could store n-3 PUFAs by the forced expression of n-3 PUFA biosynthetic enzymes. We utilized Drosophila as an insect model to generate transgenic strains expressing Caenorhabditis elegans PUFA biosynthetic enzymes and examined their effects on the proportion of fatty acids. The ubiquitous expression of methyl-end desaturase FAT-1 prominently enhanced the proportions of α-linolenic acid, indicating that FAT-1 is useful for metabolic engineering to fortify α-linolenic acid in insect. Furthermore, the ubiquitous expression of nematode front-end desaturases (FAT-3 and FAT-4), PUFA elongase (ELO-1), and FAT-1 led to EPA bioproduction. Hence, nematode PUFA biosynthetic genes may serve as powerful genetic tools for enhancing the proportion of EPA in insects. This study represents the first step toward the establishment of n-3 PUFA-producing insects.

Su(var)2-10- and Su(var)205-dependent upregulation of the heterochromatic gene neverland is required for developmental transition in Drosophila

Animals develop from juveniles to sexually mature adults through the action of steroid hormones. In insect metamorphosis, a surge of the steroid hormone ecdysone prompts the transition from the larval to the adult stage. Ecdysone is synthesized by a series of biosynthetic enzymes that are specifically expressed in an endocrine organ, the prothoracic gland. At the late larval stage, the expression levels of ecdysone biosynthetic enzymes are upregulated through the action of numerous transcription factors, thus initiating metamorphosis. In contrast, the mechanism by which chromatin regulators support the expression of ecdysone biosynthetic genes is largely unknown. Here, we demonstrate that Su(var)2-10 and Su(var)205, suppressor of variegation [Su(var)] genes encoding a chromatin regulator Su(var)2-10 and nonhistone heterochromatic protein 1a, respectively, regulate the transcription of one of the heterochromatic ecdysone biosynthetic genes, neverland, in Drosophila melanogaster. Knockdown of Su(var)2-10 and Su(var)205 in the prothoracic gland caused a decrease in neverland expression, resulting in a defect in larval-to-prepupal transition. Furthermore, overexpression of neverland and administration of 7-dehydrocholesterol, a biosynthetic precursor of ecdysone produced by Neverland, rescued developmental defects in Su(var)2-10 and Su(var)205 knockdown animals. These results indicate that Su(var)2-10- and Su(var)205-mediated proper expression of neverland is required for the initiation of metamorphosis. Given that Su(var)2-10-positive puncta are juxtaposed with the pericentromeric heterochromatic region, we propose that Su(var)2-10- and Su(var)205-dependent regulation of inherent heterochromatin structure at the neverland gene locus is essential for its transcriptional activation.

Influences of the Interactions of Genetic Variations of Seven Core Circadian Clock Genes with Lifestyle Factors on Metabolic Parameters

INTRODUCTION

In mammals, circadian rhythms regulate many behavioral and physiological processes. Genetic and epidemiological studies have shown that dysregulation of the circadian rhythm induces chronic metabolic diseases, such as obesity, diabetes, and dyslipidemia. We aimed to know the interactions of genetic variations of seven core circadian clock genes with lifestyle factors on the determination of metabolic parameters.

METHODS

We have analyzed the impacts of genotype of seven core circadian clock genes (i.e., CLOCK, BMAL1, PER1, PER2, PER3, CRY1, and CRY2) and lifestyle factors (i.e., physical activity and sleep duration) in 575 Japanese males on the determination of metabolic parameters (i.e., body mass index [BMI], serum glucose, glycated hemoglobin [HbA1c], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C] levels).

RESULTS

We have detected the associations between genotypes of PER3 and serum HbA1c level and genotypes of CRY1 and serum LDL-C level. Additionally, the interactions of the genotypes of PER1 and PER3 with physical activity for determining BMI, the genotypes of CLOCK with physical activity for determining serum HbA1c levels were observed. Furthermore, for determining serum HDL-C levels, the interactions of the genotypes of CRY2 with physical activity or sleep duration were observed.

DISCUSSION/CONCLUSION

Our findings indicate that the interactions of genotypes for core circadian clock genes and lifestyle factors (i.e., physical activity and sleep duration) are important for determining metabolic parameters.

The Nutrient-Responsive Molecular Chaperone Hsp90 Supports Growth and Development in Drosophila

Animals can sense internal nutrients, such as amino acids/proteins, and are able to modify their developmental programs in accordance with their nutrient status. In the fruit fly, Drosophila melanogaster, amino acid/protein is sensed by the fat body, an insect adipose tissue, through a nutrient sensor, target of rapamycin (TOR) complex 1 (TORC1). TORC1 promotes the secretion of various peptide hormones from the fat body in an amino acid/protein-dependent manner. Fat-body-derived peptide hormones stimulate the release of insulin-like peptides, which are essential growth-promoting anabolic hormones, from neuroendocrine cells called insulin-producing cells (IPCs). Although the importance of TORC1 and the fat body-IPC axis has been elucidated, the mechanism by which TORC1 regulates the expression of insulinotropic signal peptides remains unclear. Here, we show that an evolutionarily conserved molecular chaperone, heat shock protein 90 (Hsp90), promotes the expression of insulinotropic signal peptides. Fat-body-selective Hsp90 knockdown caused the transcriptional downregulation of insulinotropic signal peptides. IPC activity and systemic growth were also impaired in fat-body-selective Hsp90 knockdown animals. Furthermore, Hsp90 expression depended on protein/amino acid availability and TORC1 signaling. These results strongly suggest that Hsp90 serves as a nutrient-responsive gene that upregulates the fat body-IPC axis and systemic growth. We propose that Hsp90 is induced in a nutrient-dependent manner to support anabolic metabolism during the juvenile growth period.

Omega-3 Eicosapentaenoic Acid Is Related to Happiness and a Sense of Fulfillment-A Study among Female Nursing Workers

Background: Omega (ω) 3 fatty acid (FA) is a polyunsaturated FA (PUFA) that can modulate some mental statuses. However, most studies have not considered the functional differences between eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). We investigated associations among happiness, a sense of fulfillment and serum ω3 PUFA levels. Methods: Participants were 133 female staff from a hospital and nursing homes. Happiness was measured using the Japanese version of the subjective happiness scale (SHS); a sense of fulfillment was assessed using a visual analogue scale. Serum FA concentrations were measured. A partial correlation test and a regression model were applied. Results: The SHS scores showed significantly positive correlations with a sense of fulfillment, DHA% and EPA% (p < 0.05, < 0.05 and < 0.005, respectively), after controlling for age, BMI, menopause, snacking habits and leisure-time physical activities. A sense of fulfillment was significantly negatively correlated with α-linoleic acid%, and positively correlated with DHA% and EPA% (p < 0.05, < 0.05 and < 0.005, respectively), after controlling for the confounders. A regression model showed that a sense of fulfillment, EPA, and not stopping menstruation explained happiness (standardised beta, B = 0.18, p < 0.05; B = 0.24, p < 0.01; and B = 0.32, and p < 0.05, respectively), whereas age, BMI and snacking habits could not. Simultaneously, a regression model could not explain the association between DHA and happiness. Conclusion: Happiness was related with serum EPA%, a sense of fulfillment, and premenopause.

The presence of odd-chain fatty acids in Drosophila phospholipids

Most fatty acids in phospholipids and other lipid species carry an even number of carbon atoms. Also odd-chain fatty acids (OCFAs), such as C15:0 and C17:0, are widespread throughout the living organism. However, the qualitative and quantitative profiles of OCFAs-containing lipids in living organisms remain unclear. Here, we show that OCFAs are present in Drosophila phosphatidylcholine (PC) and phosphatidylethanolamine (PE) and that their level increases in accordance with progression of growth. Furthermore, we found that food-derived propionic acid/propanoic acid (C3:0) is utilized for production of OCFA-containing PC and PE. This study provides the basis for understanding in vivo function of OCFA-containing phospholipids in development and lipid homeostasis.

Loss of CNDP causes a shorter lifespan and higher sensitivity to oxidative stress in Drosophila melanogaster

Increasing oxidative stress seems to be the result of an imbalance between free radical production and antioxidant defenses. During the course of aging, oxidative stress causes tissue/cellular damage, which is implicated in numerous age-related diseases. Carnosinase (CN or CNDP) is dipeptidase, which is associated with carnosine and/or glutathione (GSH) metabolism, those are the most abundant naturally occurring endogenous dipeptide and tripeptides with antioxidant and free radical scavenger properties. In the present study, we generated Drosophila cndp (dcndp) mutant flies using the CRISPR/Cas9 system to study the roles of dcndp in vivo. We demonstrate that dcndp mutant flies exhibit shorter lifespan and increased sensitivity to paraquat or hydrogen peroxide (H₂O₂) induced oxidative stress. These results suggest that dcndp maintains homeostatic conditions, protecting cells and tissues against the harmful effects of oxidative stress in the course of aging.

Chaperonin TRiC/CCT supports mitotic exit and entry into endocycle in Drosophila

Endocycle is a commonly observed cell cycle variant through which cells undergo repeated rounds of genome DNA replication without mitosis. Endocycling cells arise from mitotic cells through a switch of the cell cycle mode, called the mitotic-to-endocycle switch (MES), to initiate cell growth and terminal differentiation. However, the underlying regulatory mechanisms of MES remain unclear. Here we used the Drosophila steroidogenic organ, called the prothoracic gland (PG), to study regulatory mechanisms of MES, which is critical for the PG to upregulate biosynthesis of the steroid hormone ecdysone. We demonstrate that PG cells undergo MES through downregulation of mitotic cyclins, which is mediated by Fizzy-related (Fzr). Moreover, we performed a RNAi screen to further elucidate the regulatory mechanisms of MES, and identified the evolutionarily conserved chaperonin TCP-1 ring complex (TRiC) as a novel regulator of MES. Knockdown of TRiC subunits in the PG caused a prolonged mitotic period, probably due to impaired nuclear translocation of Fzr, which also caused loss of ecdysteroidogenic activity. These results indicate that TRiC supports proper MES and endocycle progression by regulating Fzr folding. We propose that TRiC-mediated protein quality control is a conserved mechanism supporting MES and endocycling, as well as subsequent terminal differentiation.

Serum IL-6 levels and oxidation rate of LDL cholesterol were related to depressive symptoms independent of omega-3 fatty acids among female hospital and nursing home workers in Japan

BACKGROUND

Chronic low-grade inflammation and oxidative stress are commonly observed in persons with depression or depressive symptoms. We explored the degree of depressive symptoms under psychological stress in relation to serum LDL oxidation, inflammatory markers, and fatty acid (FA) distribution among female population. The purpose of this study was to identify peripheral factors that are related to depressive symptoms, and to assess how each factor is related to depressive symptoms.

METHODS

133 female workers in a hospital and nursing homes were recruited in Japan. Depressive symptoms were assessed using the Japanese version of the Centre for Epidemiologic Studies Depression Scale (CES-D), and perceived stress was assessed using the visual analogue scale. Cytokine levels and oxidation rate of LDL cholesterol (ox-LDL/LDL) were measured as indices of inflammation and oxidation. Omega-3 FA distribution was also measured. Path analysis and hierarchical regression analysis were used to determine if each factor was predictive of depressive symptoms.

RESULTS

It was identified that serum ox-LDL/LDL was positively connected with depressive symptoms, but was more strongly related to perceived psychological stress. Elevated serum IL-6 was positively correlated with depressive symptoms, though the effect was partly transmitted via ox-LDL/LDL. Additionally, serum ω3 PUFAs were inversely associated with depressive symptoms independently of IL-6 or ox-LDL/LDL.

CONCLUSION

Although this study is unlikely to fully explain the causes of depressive symptoms, it suggests that psychological stress and somatic factors such as inflammation, oxidation and nutrition are related to depressive symptoms. These findings suggest the therapeutic potential of lifestyle targets to alleviate the identified depression risk factors, anti-oxidative therapies, anti-inflammatory therapies and nutritional interventions to prevent depression.

Adult-specific insulin-producing neurons in Drosophila melanogaster

Holometabolous insects undergo metamorphosis to reorganize their behavioral and morphological features into adult-specific ones. In the central nervous system (CNS), some larval neurons undergo programmed cell death, whereas others go through remodeling of axonal and dendritic arbors to support functions of re-established adult organs. Although there are multiple neuropeptides that have stage-specific roles in holometabolous insects, the reorganization pattern of the entire neuropeptidergic system through metamorphosis still remains largely unclear. In this study, we conducted a mapping and lineage tracing of peptidergic neurons in the larval and adult CNS by using Drosophila genetic tools. We found that Diuretic hormone 44-producing median neurosecretory cells start expressing Insulin-like peptide 2 in the pharate adult stage. This neuronal cluster projects to the corpora cardiaca and dorsal vessel in both larval and adult stages, and also innervates an adult-specific structure in the digestive tract, the crop. We propose that the adult-specific insulin-producing cells may regulate functions of the digestive system in a stage-specific manner. Our study provides a neuroanatomical basis for understanding remodeling of the neuropeptidergic system during insect development and evolution.

The Combined Effects of Genetic Variation in the CNDP1 and CNDP2 Genes and Dietary Carbohydrate and Carotene Intake on Obesity Risk

BACKGROUND/AIMS

It is possible that carnosinase (CNDP1) and cellular nonspecific dipeptidase (CNDP2) have important roles in protecting cells and tissues against the damage of oxidative stress. Oxidative stress and subsequent inflammation are key factors in the development of common chronic metabolic diseases, such as obesity. We aimed to investigate the combined effects of genetic variations in CNDP1 and CNDP2 and dietary carbohydrate and carotene intake on obesity risk.

METHODS

A total of 1,059 Japanese men were randomly selected from participants who visited a medical center for routine medical checkups. We analyzed the relationships between the genotypes of 4 single-nucleotide polymorphisms (SNPs) (rs12605520, rs7244647, rs4891558, and rs17089368) in the CNDP1/CNDP2 locus and body mass index or prevalence of obesity/overweight taking into account dietary carbohydrate and carotene intake.

RESULTS

We found that 2 SNPs (rs7244647 in CNDP1 and rs4891558 in CNDP2) were associated with obesity risk. In addition, these associations were observed only in the group with high carbohydrate and low carotene intake but not in the group with low carbohydrate and high carotene intake.

CONCLUSIONS

Our findings indicate that the combination of genetic variations in CNDP1 and CNDP2 and dietary carbohydrate/carotene intake modulate obesity risk.

A Synergistic Effect of Serotonin Transporter Gene Polymorphism and Smoking in Association with CHD

Serotonin induces vasoconstriction in the presence of atherosclerotic lesions. Platelets acquire serotonin from the extracellular space by serotonin transporter and release it following aggregation. There is a functional polymorphism in the serotonin transporter (5-HTT) gene promoter associated with transcriptional efficacy and plasma serotonin levels. To examine whether the polymorphism is associated with coronary heart disease (CHD) in the Japanese, we analyzed 144 male CHD patients with an onset age before 65 and 222 apparently healthy men. The L allele was observed significantly more frequently in the CHD patients (26%) than in the control subjects (19%); the odds ratio was 1.48 (p <0.03). A significant interaction between the polymorphism and smoking was observed for CHD (p = 0.03), suggesting that the two have a synergistic effect on CHD. Odds ratio of the combination of the L allele and smoking was 1.95 (p <0.003). The 5-HTT gene promoter polymorphism may play a role in susceptibility to CHD, particularly when it is combined with smoking.

Perceived 6-n-Propylthiouracil (PROP) Bitterness Is Associated with Dietary Sodium Intake in Female Japanese College Students

Despite the negative health consequences of a high sodium consumption, humans consume well above the recommended levels. This study examines whether or not the dietary intake of sodium was affected by individual variation of the perceived bitterness of 6-n-propylthiouracil (PROP), and examines the relationship between the perceived bitterness of PROP and the preferred NaCl concentration of broth. Female students (20-22 y old) were recruited from the university community. Genotypes of A49P and I296V polymorphism of the TAS2R38 bitter taste receptor were determined for each subject. Samples containing NaCl, PROP or broth in 5-mL portions were evaluated by sensory testing. The participants completed a food record for each diet. Our results indicate that the individuals perceiving PROP to be more bitter had consumed a greater amount of dietary sodium. In contrast, there was no significant positive correlation between an individual's perceived saltiness and the dietary sodium intake. Those who perceived PROP to be more bitter preferred a broth containing a higher concentration of NaCl. All of these correlations were apparent even after those subjects with TAS2R38 AI/AI homozygotes (PROP non-taster) had been excluded. In conclusion, the results of this study suggest that a factor affecting the bitter rating of PROP other than the AI/AI homozygotes of TAS2R38 contributes to the variation in sodium intake and the preference for salty food.

Tea polyphenols ameliorate fat storage induced by high-fat diet in Drosophila melanogaster

Background

Polyphenols in tea are considered beneficial to human health. However, many such claims of their bioactivity still require in vitro and in vivo evidence.

Results

Using Drosophila melanogaster as a model multicellular organism, we assess the fat accumulation-suppressing effects of theaflavin (TF), a tea polyphenol; epitheaflagallin (ETG), which has an unknown function; and epigallocatechin gallate (EGCg), a prominent component of green tea. Dietary TF reduced the malondialdehyde accumulation related to a high-fat diet in adult flies. Other physiological and genetic responses induced by the high-fat diet, such as lipid accumulation in the fat body and expression of lipid metabolism-related genes, were ameliorated by the addition of TF, ETG, and EGCg, in some cases approaching respective levels without high-fat diet exposure. Continuous ingestion of the three polyphenols resulted in a shortened lifespan.

Conclusion

We provide evidence in Drosophila that tea polyphenols have a fat accumulation-suppressing effect that has received recent attention. We also suggest that tea polyphenols can provide different desirable biological activities depending on their composition and the presence or absence of other chemical components.

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Tea polyphenols have a fat accumulation-suppressing effect in Drosophila.

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Dietary theaflavin ameliorates high-fat diet-induced hydroperoxidase accumulation.

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The novel tea polyphenol epitheaflagallin strongly suppresses lipid accumulation.

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The beneficial effects of tea polyphenols can be enhanced by altering composition.

Polymorphism in microRNA-binding site in HNF1B influences the susceptibility of type 2 diabetes mellitus: a population based case-control study

Background

Recent genome-wide association studies (GWAS) have identified many SNPs associated with type 2 diabetes mellitus (T2DM). However, the functional roles for most of the SNPs have not been elucidated. MicroRNAs (miRNAs) are key regulators of gene expression involved in the development and progression of various diseases including T2DM. In this study, we investigated whether commonly occurring SNPs modulate miRNA-directed regulation of gene expression, and whether such SNPs in miRNA-binding sites are associated with the susceptibility for T2DM.

Methods

Genotypes of eleven 3′ untranslated region (UTR) SNPs of seven susceptibility genes for T2DM were determined in 353 T2DM patients and 448 control subjects. In addition, the interactions of miRNAs with the 3′UTR in the hepatocyte nuclear factor 1β (HNF1B) gene were investigated using luciferase reporter assays.

Results

One 3′UTR SNP (rs2229295) in the HNF1B gene was significantly associated with T2DM, and the frequency of an A allele (rs2229295) in T2DM patients was decreased compared with that in controls. Luciferase reporter assays showed that the SNP (rs2229295) altered the binding of two miRNAs (hsa-miR-214-5p and hsa-miR-550a-5p).

Conclusions

We have detected the interactions of hsa-miR-214-5p/hsa-miR-550a-5p and the 3′UTR SNP of the HNF1B gene by in vitro luciferase reporter assays, and propose that the binding of such miRNAs regulates the expression of the HNF1B gene and the susceptibility of T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0219-5) contains supplementary material, which is available to authorized users.

A heteroallelic Drosophila insulin-like receptor mutant and its use in validating physiological activities of food constituents

Here we report an additional Drosophila transheterozygote InR(GS15311)/InR(GS50346) carrying two different P-element-inducible alleles of insulin-like receptor gene (InR). InR(GS15311)/InR(GS50346) flies exhibit the following phenotypes previously reported in InR and insulin/IGF-1 signaling (IIS) pathway-related gene mutants: small bodies, developmental delay, shortened lifespan, and increased fasting resistance. All of these characteristics are shared among flies carrying mutated genes implicated in the pathway. This heteroallelic combination exhibited fertility but resulted in male semilethality, while females were viable and grew into adults. Furthermore, an experimental model employing the InR(GS15311)/InR(GS50346) strain confirmed negligible involvement of royal jelly in IIS. Thus, the heteroallelic InR mutant, discovered in this study, will serve as a good model for multiple purposes: investigating the IIS mechanisms; identifying and validating the ingredients that prevent type II diabetes; and screening of food constituents associated with IIS.

The combined effects of genetic variation in the SIRT1 gene and dietary intake of n-3 and n-6 polyunsaturated fatty acids on serum LDL-C and HDL-C levels: a population based study

Background

Dyslipidemia due to high total cholesterol, LDL-cholesterol, triglycerides, or low HDL-cholesterol is an important risk factor for coronary heart disease (CHD). Both SIRT1 and PUFAs can influence the expression of genes for nuclear receptors and transcription factors related to lipid metabolism such as LXRα, LXRβ, PPARα, SREBP-1c.

Methods

A total of 707 Japanese males and 723 females were randomly selected from the participants who visited a medical center for routine medical check-ups. We analyzed the combined effects of the genotype/haplotype of the SIRT1 gene and dietary n-6/n-3 PUFA intake ratio on the determination of serum lipid levels.

Results

We found that the SIRT1 gene marked with haplotype 2 was associated with decreased serum LDL-cholesterol and increased HDL-cholesterol levels. In addition, the associations between the SIRT1 haplotype 2 and decreased LDL-C and increased HDL-C levels were only observed in the low n-6/n-3 PUFA intake ratio group, but not in the high n-6/n-3 PUFA intake ratio group.

Conclusions

Our findings indicate that the combination of genetic variation in the SIRT1 gene and dietary n-6 and/or n-3 PUFA intake influence the determination of inter-individual variations of serum levels of LDL-C and HDL-C.

Expression of β-adrenergic-like octopamine receptors during Drosophila development

An invertebrate biogenic amine, octopamine, plays diverse roles in multiple physiological processes (e.g. neurotransmitter, neuromodulator, and circulating neurohormone). Octopamine is thought to function by binding to G-protein-coupled receptors. In Drosophila, three β-adrenergic-like octopamine receptors (Octβ1R, Octβ2R, and Octβ3R) have been identified. We investigated the expression of three OctβR genes in embryos, larvae, and adults. These OctβRs showed distinct expression patterns in the central nervous system (CNS) throughout development, and Octβ3R expression was evident in an endocrine organ, the ring gland, in larvae. In larvae, Octβ1R, Octβ2R, and Octβ3R were expressed in salivary glands and imaginal discs, Octβ2R and Octβ3R in midgut, and Octβ3R in gonads. In adult, besides in the CNS, each OctβR was strongly expressed in ovary and testis. Our findings provide a basis for understanding the mechanisms by which OctβRs mediate multiple diverse octopaminergic functions during development.

The combined effect of the T2DM susceptibility genes is an important risk factor for T2DM in non-obese Japanese: a population based case-control study

Background

Type 2 diabetes mellitus (T2DM) is a complex endocrine and metabolic disorder. Recently, several genome-wide association studies (GWAS) have identified many novel susceptibility loci for T2DM, and indicated that there are common genetic causes contributing to the susceptibility to T2DM in multiple populations worldwide. In addition, clinical and epidemiological studies have indicated that obesity is a major risk factor for T2DM. However, the prevalence of obesity varies among the various ethnic groups. We aimed to determine the combined effects of these susceptibility loci and obesity/overweight for development of T2DM in the Japanese.

Methods

Single nucleotide polymorphisms (SNPs) in or near 17 susceptibility loci for T2DM, identified through GWAS in Caucasian and Asian populations, were genotyped in 333 cases with T2DM and 417 control subjects.

Results

We confirmed that the cumulative number of risk alleles based on 17 susceptibility loci for T2DM was an important risk factor in the development of T2DM in Japanese population (P < 0.0001), although the effect of each risk allele was relatively small. In addition, the significant association between an increased number of risk alleles and an increased risk of T2DM was observed in the non-obese group (P < 0.0001 for trend), but not in the obese/overweight group (P = 0.88 for trend).

Conclusions

Our findings indicate that there is an etiological heterogeneity of T2DM between obese/overweight and non-obese subjects.

The combination of genetic variations in the PRDX3 gene and dietary fat intake contribute to obesity risk

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of the cell. This imbalance and an excess of ROS induce tissue/cellular damage, which are implicated in chronic inflammation disorders such as obesity, insulin resistance, and metabolic syndromes. Peroxiredoxins (Prxs) are the most abundant and ancient cellular antioxidant proteins that help to control intracellular peroxide levels and ROS-dependent signaling. Of the six mammalian isoforms, Prx III is specifically localized in mitochondria. In this study, we detected novel associations between genetic variations of the PRDX3 gene and BMI and obesity risk in the general Japanese population. In addition, these associations were observed only in the subjects with high dietary fat intake, but not in the subjects with low dietary fat intake. These findings indicate that the interaction between genetic variations in the PRDX3 gene and dietary fat intake is important for modulation of BMI and obesity risk.

Proteome analysis reveals elevated serum levels of clusterin in patients with preeclampsia

Preeclampsia is a pregnancy-specific syndrome and a major cause of maternal mortality. The pathophysiology of preeclampsia is unknown, and no proteome analysis of preeclampsia has been reported. We sought to identify proteins associated with preeclampsia using a proteomic technique and performed two-dimensional electrophoresis (2-DE) on sera from six patients with preeclampsia and six normal pregnant women, followed by comparison of the SYPRO Ruby-stained 2-DE profiles. A group of overexpressed spots was identified in the limited study set. Overexpressed spots were identified as clusterin by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) followed by peptide mass fingerprinting, a protein database search, and Western blot analysis. Additionally, sera of 80 preeclamptic women and 80 normal pregnant women were processed by immunoassay methods to confirm changes in clusterin concentrations quantitatively. Immunoassays showed that clusterin levels in the 80 preeclamptic women were significantly higher than those in the 80 controls (mean +/- SD; 1.62 +/- 0.46 times reference level in preeclamptic women vs. 1.30 +/- 0.46 times reference level in controls, P < 0.001). Proteomic analysis of serum proteins is a promising tool for studying preeclampsia pathophysiology and identifying proteins associated with preeclampsia.

Associations between serum high-density lipoprotein cholesterol or apolipoprotein AI levels and common genetic variants of the ABCA1 gene in Japanese school-aged children

ATP-binding cassette transporter A1 (ABCA1) plays an important role in apolipoprotein AI (apoAI)-mediated cholesterol efflux from peripheral cells. The mild changes in ABCA1 activity due to genomic variation might be associated with interindividual variations in serum high-density lipoprotein cholesterol (HDL-C) and apoAI levels, or primary hypoalphalipoproteinemia in the general population. In the present study, we analyzed the relationships between 5 single nucleotide polymorphisms (SNPs) and 2 insertion/deletion polymorphisms in the 5' flanking region and 5 missense polymorphisms of the ABCA1 gene and serum lipid levels in healthy school-aged children. We detected significant associations between the K219R and V771M polymorphisms, and HDL-C or apoAI levels. The present data support the proposition that the K219 allele is an anti-atherogenic allele with increased cholesterol efflux activity. Similarly, the M771 allele appears to be anti-atherogenic, although the frequency of the M771 allele is low.

Significant linkage to chromosome 22q for exploratory eye movement dysfunction in schizophrenia

A genome-wide scan for a locus responsible for exploratory eye movement (EEM), which is quantitative and can be disturbed in association with schizophrenia, was performed. A 10-cM resolution genome-wide linkage analysis of the EEM disturbance with 358 highly polymorphic microsatellite markers in 38 nuclear families with 122 members (38 probands, 47 sibs, and 37 parents) including 58 sib-pairs yielded the suggestive linkage to the GCT10C10 marker on chromosome 22q11.2 (LOD = 2.48). Dense mapping with additional markers around the GCT10C10 marker yielded evidence for significant linkage between EEM disturbance and markers D22S429 and D22S310 on chromosome 22q12.1 (LOD score of 4.63) with suggestive evidence for the chromosome region 22q11.2-q12.1. Our findings suggest that a relatively small number of loci may control the schizophrenia-related quantitative EEM trait. We believe that identifying gene(s) on chromosome 22q associated with the EEM phenotype may forward our understanding of the etiology of schizophrenia.

Relationship between serum HDL-C levels and common genetic variants of the endothelial lipase gene in Japanese school-aged children

Endothelial lipase (EL) is a new member of the triglyceride lipase family, the genes of which play a central role in dietary fat absorption, energy homeostasis, and plasma lipoprotein metabolism. One physiologic role of EL is thought to be hydrolysis of high-density lipoprotein (HDL) phospholipid, although the precise function of endothelial lipase has yet to be fully clarified. Furthermore, genetic variation in EL has been suggested to influence serum HDL-C levels. In the present study, we detected two common single nucleotide polymorphisms in the EL gene associated with serum HDL cholesterol levels in healthy school-aged children. Our data support the hypothesis that variations in the EL gene are one of the genetic determinants of serum HDL-C levels.

Association found between the promoter region polymorphism in the apolipoprotein A-V gene and the serum triglyceride level in Japanese schoolchildren

The purpose of this study was to assess the influence of single nucleotide polymorphism 3 (SNP3) of the apolipoprotein A-V ( APOA5) gene on the serum triglyceride (TG) level in Japanese schoolchildren. To determine the frequency of the genotype, we analyzed 552 schoolchildren. The frequencies of the T/T, T/C and C/C genotypes of the APOA5 gene were 225 (40.8%), 263 (47.6%) and 64 (11.6%), respectively. The serum TG level was significantly different among the genotypic groups after adjustments for age, gender and obesity index (T/T 71.6+/-34.8 mg/dl, T/C 80.7+/-36.1 mg/dl, C/C 94.4+/-69.4 mg/dl, P<0.0001). The odds ratio (95% confidence interval) for hypertriglyceridemia of the C allele was 2.4 (1.0-6.2). Our data suggested that the T/C promoter region polymorphism of the APOA5 gene appears to be a genetic risk factor for hypertriglyceridemia in Japanese children.

Association analysis of nine missense polymorphisms in the coagulation factor V gene with severe preeclampsia in pregnant Japanese women

The Leiden mutation in the coagulation factor V (F5) gene associated with preeclampsia in Caucasians has not been found in Japanese populations. We examined the association of 20 missense polymorphisms in the F5 gene in 133 pregnant Japanese women with preeclampsia and in 224 unrelated, healthy, pregnant Japanese women. Among nine polymorphisms identified in the subjects, the M385T and R485K polymorphisms were associated with preeclampsia (P = 0.05 and P = 0.02, respectively). Haplotype analysis indicated that the R485K polymorphism is truly associated with preeclampsia, whereas the association of the M385T polymorphism is due to linkage disequilibrium. Taken together with reports that the R485 allele yields poor factor V function in comparison with that of the K485 allele and that the F5 Leiden mutation is associated with preeclampsia in Caucasian populations, the findings of the present study suggest that the F5 gene is associated with preeclampsia in pregnant Japanese women.

Failure to find evidence for association between voltage-gated sodium channel gene SCN2A variants and febrile seizures in humans

The voltage-gated sodium channel type II alpha polypeptide gene (SCN2A) R188W mutation with channel dysfunction was recently identified in a patient with febrile and afebrile seizures. A possible association between SCN2A R19K polymorphism and febrile seizures (FS) associated with afebrile seizures including generalized epilepsy with febrile seizures plus (GEFS+) was also noted. We attempted to identify the R188W mutation and confirm association of the R19K polymorphism in 93 Japanese patients with FS, 35 Japanese patients with FS associated with afebrile seizures including GEFS+, and 100 control subjects. The R188W mutation was not found. There were no significant differences in genotype or allele frequencies of the R19K polymorphism between groups. Our study failed to provide evidence supporting a causal relation between the SCN2A mutation/polymorphism and FS or FS associated with afebrile seizures including GEFS+ in the Japanese population.

Association between TNFA polymorphism and the development of asthma in the Japanese population

Tumor necrosis factor (TNF) is a proinflammatory cytokine that participates in the inflammatory reaction in patients with asthma. The TNFA and TNFB genes, which encode TNF-alpha and TNF-beta, respectively, are located within the region encoding the human major histocompatibility complex on chromosome 6p21.3, which showed linkage to atopic asthma in our genome-wide search. To determine whether polymorphisms in the 5' flanking region of the TNFA gene (-1031C/T, -863C/A, and -857C/T) and an NcoI polymorphism in the TNFB gene (LTA NcoI) are associated with the development of asthma, we performed transmission disequilibrium tests of families identified through children with atopic asthma. Genotypes of families were determined by polymerase chain reaction-based restriction fragment length polymorphism or SNaPshot analysis. Transmission disequilibrium tests of 144 asthmatic families revealed that transmission of the -857C allele and the -1031T-863C-857C haplotype in the TNFA gene to asthma-affected offspring occurred more frequently than expected (-857C allele, p = 0.0055; -1031T-863C-857C haplotype, p = 0.0002). Our results suggest that TNFA or nearby genes, including those in the major histocompatibility complex region, may contribute to the development of asthma in the Japanese population.

Evidence for an association between plasma platelet-activating factor acetylhydrolase deficiency and increased risk of childhood atopic asthma

Platelet-activating factor (PAF), which has been implicated in the pathophysiology of inflammation in asthma, is degraded and inactivated by PAF acetylhydrolase (PAFAH). Approximately 4% of the Japanese population lacks plasma PAFAH due to a loss-of-function variant (Val279Phe) in the PAFAH gene. Although lack of PAFAH activity is thought to be a risk factor for asthma, there are conflicting findings concerning association between the Val279Phe variant and asthma. In this study, we conducted transmission disequilibrium tests of 118 Japanese parent-child trios identified through mite-sensitive atopic asthmatic children. A case-control study was also carried out. The Phe279/Phe279 genotype was found more frequently in children with atopic asthma (13%) than in their parents (6%) or in controls (4%). Results of the genotypic transmission test were significant, and the Phe279/Phe279 genotype was transmitted preferentially to asthmatic children. Our data support an association between deficiency in PAFAH activity and atopic asthma.

Relation of the -514C/T polymorphism in the hepatic lipase gene to serum HDL and LDL cholesterol levels in postmenopausal women under hormone replacement therapy

Hepatic lipase (HL) is a lipolytic enzyme that catalyzes hydrolysis of triglycerides and phospholipids in all major classes of lipoproteins. Recently, a -514C/T polymorphism in the promoter region of the HL gene was found to be associated with variations in hepatic lipase activity and serum high density lipoprotein cholesterol (HDL-C) levels. Postmenopausal hormone replacement therapy (HRT) has known favorable effects on serum lipid and lipoprotein levels. In this study, we examined the relation between the -514C/T polymorphism and serum lipid and lipoprotein levels in postmenopausal women prior to and after 3 months of HRT. Significant associations between the -514 C/T polymorphism and HDL-C, low density lipoprotein cholesterol (LDL-C) and apolipoprotein A-I (apo A-I) levels were observed before and/or after 3 months of HRT. With HRT, serum total cholesterol (TC), LDL-C and apolipoprotein B (apo B) levels were reduced significantly (P=0.0001), and HDL-C and apo A-I levels were increased significantly (P=0.0001). However, the degrees of change in lipid and lipoprotein levels due to HRT did not differ significantly between the HL genotypes.

Identification of 33 polymorphisms in the adipocyte-derived leucine aminopeptidase (ALAP) gene and possible association with hypertension

Adipocyte-derived leucine aminopeptidase (ALAP) inactivates angiotensin II and/or generates bradykinin in the kidney, suggesting a possible role for ALAP in the regulation of blood pressure. We considered the hypothesis that genomic variants of the ALAP gene are associated with hypertension or individual variations in blood pressure. We screened for mutations in the ALAP gene in 48 unrelated Japanese individuals and identified 33 polymorphisms including 15 novel polymorphisms. We then performed a two-stage analysis. In the first stage, the eight missense polymorphisms were evaluated for associations with blood pressure in 96 apparently healthy individuals. In the second stage, only the most promising polymorphisms were evaluated for association with essential hypertension in 143 hypertensive and 348 normotensive subjects. Among the eight missense polymorphisms, the Ile276Met and Lys528Arg polymorphisms showed significant association with blood pressure. Subsequent analysis confirmed association between the Lys528Arg polymorphism and essential hypertension. The estimated odds ratio for essential hypertension was 2.3 for presence of the Arg allele at codon 528, in comparison with presence of the Lys/Lys genotype (P = 0.004). These findings support involvement of ALAP in the regulation of blood pressure.

A genome-wide linkage analysis of orchard grass-sensitive childhood seasonal allergic rhinitis in Japanese families

Seasonal allergic rhinitis (SAR) is an inflammatory disease of the nose and eyes that follows sensitization to air-born pollens. We conducted a genome-wide linkage screening of 48 Japanese families (188 members) with orchard grass (OG)-sensitive SAR children (67 affected sib-pairs) in a farming community in central Japan where OG was planted for apple farming and OG pollen is a major cause of SAR. We used the GENEHUNTER program to performed nonparametric multipoint linkage analysis for OG-sensitive SAR as a qualitative trait and for log total serum IgE levels and OG-RAST IgE levels as quantitative traits. Genotyping data of 400 microsatellite markers suggested linkage of SAR to chromosomes 1p36.2, 4q13.3, and 9q34.3 (P < 0.001), linkage of serum total IgE levels to 3p24.1, 5q33.1, 12p13.1, and 12q24.2 (P < 0.001), and linkage of OG-RAST IgE levels to 4p16.1, 11q14.3, and 16p12.3 (P < 0.001). Weak evidence for linkage of SAR to 5q33.1 was also observed (P = 0.01). All these regions, with the exception of 9q34.3, have been previously reported to be linked to asthma and/or atopy. These data suggest that, although loci linked to SAR are likely to be common to asthma, a strong contribution by specific gene(s) to OG-sensitive SAR is unlikely.

Mutation analysis of the retinoid X receptor beta, nuclear-related receptor 1, and peroxisome proliferator-activated receptor alpha genes in schizophrenia and alcohol dependence: possible haplotype association of nuclear-related receptor 1 gene to alcohol dependence

Because retinoid cascades are involved in the regulation and development of the central nervous system, including dopaminergic neurons, retinoic acid signaling defects may contribute to schizophrenia and substances dependence. Retinoid X receptors (RXRs) form heterodimer complexes with nuclear-related receptor 1 (NURR1) or with peroxisome proliferator-activated receptors (PPARs). We examined 48 Japanese patients with schizophrenia and 32 patients with alcohol dependence to detect mutations in the retinoid X receptor beta gene (RXRB) on chromosome 6p21.3, the NURR1 gene (NR4A2) on chromosome 2q22-q23, and the PPAR alpha gene (PPARA) on chromosome 22q12.2-13.1. A Val95Ala polymorphism of the RXRB gene, a Val227Ala polymorphism in the PPARA gene, and two synonymous single-nucleotide and CA repeat polymorphisms in the 5' region and 3' untranslated region of the NR4A2 gene were identified. Extended case control samples did not suggest an association between the diseases and the RXRB or PPARA polymorphisms. However, they revealed a significant association between the NR4A2 gene haplotype and alcohol dependence, indicating that 2q22-q23 including the NR4A2 gene locus is a possible genomic region contributing to genetic susceptibility to alcohol dependence.

New polymorphisms of haematopoietic prostaglandin D synthase and human prostanoid DP receptor genes

BACKGROUND

Prostaglandin D2 (PGD2), a major cyclo-oxygenase metabolite of arachidonic acid in mast cells, induces bronchoconstriction in the human lung. It has been reported that mice lacking PGD receptor fail to develop the bronchial hyper-responsiveness upon ovalbumin challenge, suggesting that PGD2 functions as a mediator of allergic asthma.

OBJECTIVE

To determine if there are any mutations associated with the development of asthma in the haematopoietic prostaglandin D synthase (H-PGDS) gene and the human prostanoid DP receptor (PTGDR) gene.

METHODS AND RESULTS

We screened the 5'flanking and coding regions of the H-PGDS gene and the PTGDR gene by direct sequence. We identified one variant in intron 2 (IVS2 + 11 A > C) and one variant in intron 3 (IVS3 + 13T > C) of the H-PGDS gene, and two variants in the 5'flanking region of the PTGDR gene (-197T > C and -2C > T). The IVS3 + 13T > C and -197T > C variants were rare, appearing only once in 48 subjects. transmission disequilibrium test (TDT) analysis of 144 asthmatic families revealed that the IVS2 + 11 A allele of the H-PGDS gene was significantly transmitted preferentially to asthma-affected children (P = 0.0056), but no association was observed between -2C/T polymorphism of the PTGDR gene and asthma (P > 0.05).

CONCLUSION

Our results suggest that the IVS2 + 11A/C allele may be involved in the development of asthma in the Japanese population.

Association of ZNF74 gene genotypes with age-at-onset of schizophrenia

Because of the manifestation of schizophrenic symptoms in individuals with interstitial deletions of chromosome 22q11.2, genes located in 22q11.2 are positional candidates for schizophrenia susceptibility. We genotyped five polymorphisms at D22S941, D22S944, D22S264, and D22S311, and the COMT gene in the common 3Mbp deletion region associated with 22q11 deletion syndrome in 300 Japanese schizophrenics and 300 controls and identified one patient with 22q11 deletion (Arinami et al., 2001). The results showed a trend of different genotypic distributions in D22S264 between patients with schizophrenia and controls (non-corrected p=0.04). Given this finding, we searched for mutations in the ZNF74 gene, which is located 11.2Kbp centromeric to D22S264. The ZNF74 gene is a member of the KRAB-zinc finger gene family and is expressed in the developing brain. Four polymorphisms, 1150T/C, IVS2a-40G/A, E/K46, and [K/N551;L/F552], were detected. The first three polymorphisms were in almost complete linkage disequilibrium. Case-control comparisons for these polymorphisms resulted in similar genotypic and allelic frequencies in patients and controls. The polymorphisms, however, were significantly associated with age-at-onset of schizophrenia (n<0.0001). Subsequent analyses in another Japanese schizophrenic population (n=169) confirmed an age-at-onset association (p<0.0001). These findings suggest that the ZNF74 gene plays a role as one of the modifying factors for schizophrenia.

Identification of missense mutation in the IL12B gene: lack of association between IL12B polymorphisms and asthma and allergic rhinitis in the Japanese population

Interleukin-12 (IL-12) is a macrophage-derived cytokine that modulates T lymphocyte responses and can suppress allergic inflammation. In a genome-wide screen, we found strong evidence for linkage of atopic asthma with marker D5S1352, located close to IL12B, with a maximum lod score of 4.34. We screened for mutation in IL12B and found three novel (-4475-4insG, Glu186Asp and Ser226Asn) variants and one previously reported (1188A>C) variant in IL12B, and conducted transmission disequilibrium tests in families identified through children with atopic asthma or allergic rhinitis. Frequencies of the Asn226 and 1188C alleles in the parents were 0.04 and 0.5, respectively. Preferential transmission of either the Ser226/Asn226 or 1188A/C allele to asthma-affected or rhinitis-affected children was not observed (P > 0.1) and was not associated significantly with total serum IgE level (P > 0.1). Our results indicate that polymorphisms in IL12B are not likely to be associated with the development of atopy-related phenotypes.

Haplotypes of the 5' region of the IL-4 gene and SNPs in the intergene sequence between the IL-4 and IL-13 genes are associated with atopic asthma

IL-4 and IL-13 are important in IgE synthesis and allergic inflammation. Therefore, genes encoding IL-4 and IL-13 are candidates for predisposition to asthma and atopy. A recent study in the YAC transgenic mouse has revealed that one of the conserved noncoding sequences (CNS-1) between IL-4 and IL-13 influences the expression of IL-4, IL-5, and IL-13, suggesting that CNS-1 acts as a coordinate regulator of these genes. This investigation screened for mutations in the 13-kb region between IL-4 and IL-13, which includes the human equivalent of the murine CNS-1. Four single nucleotide polymorphisms (SNPs) were found in the region between IL-4 and IL-13 (IL-4-IL-13SNP1, IL-4-IL-13SNP2, IL-4-IL-13SNP3, and IL-4-IL-13SNP4). There was no mutation in the human CNS-1. We genotyped these and other previously reported polymorphisms in IL-4 and IL-13 using asthmatic families, and examined association by transmission disequilibrium test. Two-locus haplotype analysis revealed that haplotypes composed of the IL-4 RP2del, IL-4 +33T, or IL-4 -589T alleles and either IL-4-IL-13SNP3G or IL-4-IL-13SNP4C are transmitted significantly to asthma-affected children (p = 0.002). This data suggests that haplotypes composed of the 5' region polymorphisms in the IL-4 gene and SNPs in the intergene sequence between IL-4 and IL-13 influence the development of asthma.

Association between a new polymorphism in the activation-induced cytidine deaminase gene and atopic asthma and the regulation of total serum IgE levels

BACKGROUND

Activation-induced cytidine deaminase (AICDA) is a recently identified RNA-editing deaminase that plays an important role in class-switching. Defects in AICDA result in a hyper-IgM phenotype and lack of IgG, IgA, and IgE in both human beings and mice.

OBJECTIVE

The aim of this study was to determine whether the AICDA gene is related to regulation of total serum IgE and development of atopic asthma.

METHODS

We screened for polymorphisms in the 5;-flanking and coding regions of the AICDA gene in subjects with atopic asthma and analyzed the effect of these polymorphisms on the development of atopic asthma and on total serum IgE levels in Japanese asthmatic families.

RESULTS

We identified 3 novel polymorphisms (5923A/G, 7888C/T, and 8578A/C) and 1 rare variant (Arg25Cys) in the AICDA gene. Transmission disequilibrium testing showed that the 7888C allele was transmitted preferentially to asthma-affected children (P =.007). Mean log [total serum IgE] levels of parents with the 7888C/7888C, 7888C/7888T, and 7888T/7888T genotypes were 2.12, 1.99, and 1.77, respectively, and a significant association was observed between the genotypes (P =.02). In RT-PCR experiments, we found 2 novel splice variants of AICDA, one lacking all of exon 4 (variant 1; 367 base pairs) and the other lacking the first 30 base pairs of exon 4 (variant 2; 453 base pairs). These variants were not associated with the 7888C/T polymorphism.

CONCLUSION

The 7888C/T polymorphism might be associated with the pathogenesis of atopic asthma and the regulation of total serum IgE levels.

Mutation analysis of the NMDAR2B (GRIN2B) gene in schizophrenia

NMDA receptor dysfunction may be involved in the pathophysiology of schizophrenia. Based on this hypothesis, we screened 48 Japanese patients with schizophrenia for mutations in the coding region of the NMDAR2B subunit gene (GRIN2B). An association study between the identified DNA sequence variants and schizophrenia was performed in 268 Japanese patients with schizophrenia and 337 Japanese control subjects. Eight single nucleotide polymorphisms were detected, all of which were synonymous. The association sample showed statistically significant excesses of homozygosity for the polymorphisms in the 3' region of the last exon in the patients with schizophrenia (P = 0.004) and higher frequency of the G allele of the 366C/G polymorphism (corrected P = 0.04) in the patients than in the controls. Although we did not detect NMDAR2B protein variants, our findings support the possibility that the GRIN2B gene or a locus in linkage disequilibrium with it may confer susceptibility to schizophrenia. Replication studies in independent samples are warranted.

Mutation analysis of the N-methyl-D-aspartate receptor NR1 subunit gene (GRIN1) in schizophrenia

Dysfunction of N-methyl-D-aspartate (NMDA) type ionotropic glutamate receptors has been implicated in the etiology of schizophrenia based on psychotomimetic properties of the antagonist phencyclidine (PCP) and observation that mice expressing low levels of the N-methyl-D-aspartate receptor NR1 subunit exhibit behavioral alterations that may be ameliorated by neuroleptic drugs. Based on the hypothesis that some schizophrenic patients have functionally deficient mutation(s) of the gene encoding N-methyl-D-aspartate receptor NR1 subunit (GRIN1), we screened 48 Japanese patients with schizophrenia for mutations in the coding region of the GRIN1 gene. Four variants, IVS2-22T>C, IVS2-12G>A, IVS4-34C>T, and 1719G/A (Pro516Pro), were identified. No non-synonymous mutation was detected. No significant association was suggested by case-control comparisons. Results indicate that genomic variations of the GRIN1 gene are not likely to be involved substantially in the etiology of schizophrenia.

Mutation screening of interferon regulatory factor 1 gene (IRF-1) as a candidate gene for atopy/asthma

BACKGROUND

IL-4 gene cluster on chromosome 5 contains several candidate genes for atopy and asthma. Several independent studies have shown evidence for linkage between the markers flanking IL-4 gene cluster and asthma and/or asthma-related traits. Interferon regulatory factor 1 (IRF-1) is located approximately 300 kb telomeric to IL-4 and recent study reveals that IRF-1 deficiency results in an elevated production of Th2-related cytokines and a compensatory decrease in the expression of native cell- and Th1-related cytokines.

OBJECTIVE

To determine if there are any mutations associated with the development of atopy and asthma present in the coding exons and 5' flanking region of the IRF-1 gene.

METHODS AND RESULTS

We have screened the promoter and coding regions of the IRF-1 gene in atopic asthmatics and controls by SSCP method. We found three novel nuclear variants (the -300G/T and 4396 A/G polymorphisms and the 6355G > A rare variant) in the IRF-1 gene. No variants causing amino acid alterations of IRF-1 were detected. The -300G/T polymorphism was in nearly complete linkage disequilibrium with the 4396 A/G polymorphism. An association between the 4396 A > G polymorphism and atopy/asthma was examined by transmission disequilibrium test in 81 asthmatic families. Either of 4396 A or 4396G alleles was not significantly preferentially transmitted to atopy- or asthma-affected children.

CONCLUSION

The IRF-1 gene is less likely to play a substantial role in the development of atopy and asthma in the Japanese population.

The 4G/5G polymorphism of the plasminogen activator inhibitor-1 gene is associated with severe preeclampsia

Preeclampsia is associated with thrombosis of the intervillous or spiral artery. A deletion/insertion polymorphism (4G or 5G) in the promoter of the plasminogen activator inhibitor type 1 (PAI-1) gene is suggested to be involved in regulating the synthesis of the inhibitor, 4G allele, being associated with the enhanced gene expression and plasma PAI-1 levels. We assessed the association between preeclampsia and the 4G/5G polymorphism of the PAI-1 gene in 115 preeclamptic patients, 210 pregnant controls, and 298 healthy volunteer controls. The frequency of the homozygotes for the 4G allele was significantly higher in the patients than in the control pregnant women (P = 0.04) or in the healthy volunteers (P = 0.02). The 4G allele frequency was also significantly higher in the patients than in the control group of pregnant women (P = 0.03) and in the healthy volunteers (P = 0.02). These results suggest that the presence of the 4G/4G genotype of the PAI-1 gene is one of the risk factors for preeclampsia.

Significant evidence for linkage of mite-sensitive childhood asthma to chromosome 5q31-q33 near the interleukin 12 B locus by a genome-wide search in Japanese families

Childhood-onset asthma is frequently found in association with atopy. Although asthmatic children may develop IgE antibodies against variety of allergens, asthma is associated primarily with allergy to house-dust mites, molds, or other allergens. In this study, we conducted a genome-wide linkage search in 47 Japanese families (197 members) with more than two mite-sensitive atopic asthmatics (65 affected sib-pairs) using 398 markers. Multipoint linkage analysis was carried out for atopic asthma as a qualitative trait using the MAPMAKER/SIB program. We observed significant evidence for linkage with maximum lod scores (MLS) of 4.8 near the interleukin 12 B gene locus on chromosome 5q31-q33. In addition, suggestive evidence on 4q35 with MLS = 2.7 and on 13q11 with MLS = 2.4 was obtained. The other possible linkage regions included 6p22-p21.3 (MLS = 2.1), 12q21-q23 (MLS = 1.9), and 13q14.1-q14.3 (MLS = 2.0). Many of the linkage loci suggested in this study were at or close to those suggested by genome-wide studies for asthma in Caucasian populations. The present study suggests the contribution of the interleukin 12 B gene or nearby gene(s) to mite-sensitive atopic asthma and a considerable number of genetic variants common across Caucasians and Japanese populations contributing to asthma, although the relative importance of various variants may differ between the groups.

No association between atopic asthma and a coding variant of Fc epsilon R1 beta in a Japanese population

Susceptibility to atopic diseases is known to involve genetic factors. The Gly237 allele of a polymorphism (Glu237Gly) of the Fc epsilon R1 beta gene is reportedly associated with atopic asthma in Japanese. To confirm this association, we conducted transmission disequilibrium tests in 76 families identified through atopic asthmatics. A case-control study was also carried out in atopic asthmatic subjects and non-atopic controls. The Gly237 allele was not preferentially transmitted to atopic asthma-affected offspring. Neither the Gly237 allele nor the Gly237/Gly237 + Glu237/Gly237 genotypes were significantly more prevalent in the atopic asthmatics than in the controls. This study failed to confirm a substantial role of the Gly237Glu polymorphism of the Fc epsilon R1 beta gene in the genetic predisposition for atopic asthma in this Japanese population.