Investigating the role of protein folding and assembly in cell-type dependent expression of alpha7 nicotinic receptors using a green fluorescent protein chimera

To test the hypothesis that cell-dependent expression of alpha7 receptors is due to differences in protein folding or assembly, we constructed a chimeric rat alpha7 subunit with green fluorescent protein (GFP) at the receptor C-terminal. Expression of alpha7-GFP in Xenopus oocytes resulted in currents that were indistinguishable from wild type receptors but were only 33% of control. (125)I-alpha-bungarotoxin (alphaBGT) binding at the oocyte surface was reduced to 23% of wild type. Transfection of alpha7-GFP into GH4C1 cells produced fluorescence that was less intense than GFP alone, but showed significant alpha-BGT binding compared to transfection with GFP. In contrast, alpha7-GFP transfection in SH-EP1, HEK293 and CHO-CAR cells produced fluorescence without alphaBGT binding. Flow cytometry of cells transfected with alpha7-GFP indicated fluorescence in both SH-EP1 and GH4C1 cells, but surface toxin binding sites and sites immunoprecipitated using anti-GFP antibodies were undetectable in SH-EP1 cells, suggesting a problem in folding/assembly rather than trafficking. Surprisingly, integrated fluorescence intensities in GH4C1 cells transfected with alpha7-GFP did not correlate with amounts of cell surface or immunoprecipitable alphaBGT binding. Therefore, GFP folding at the C-terminal of the alpha7-GFP chimera is cell-line independent, but toxin binding is highly cell-line dependent, suggesting that if altered protein folding is involved in the cell-type dependence of alpha7 receptor expression, the phenomenon is restricted to specific protein domains. Further, C-terminal GFP-labeled alpha7 receptors decreased the efficiency of folding/assembly not only of chimeric subunits, but also wild-type subunits, suggesting that the C-terminal is an important domain for alpha7 receptor assembly.

Type 2 diabetes-associated genetic variants discovered in the recent genome-wide association studies are related to gestational diabetes mellitus in the Korean population

AIMS/HYPOTHESIS

New genetic variants associated with susceptibility to type 2 diabetes mellitus have been discovered in recent genome-wide association (GWA) studies. The aim of the present study was to examine the association between these diabetogenic variants and gestational diabetes mellitus (GDM).

METHODS

The study included 869 Korean women with GDM and 345 female and 287 male Korean non-diabetic controls. We genotyped the single nucleotide polymorphisms (SNPs) rs7756992 and rs7754840 in CDKAL1; rs564398, rs1333040, rs10757278 and rs10811661 in the CDKN2A-CDKN2B region; rs8050136 in FTO; rs1111875, rs5015480 and rs7923837 in HHEX; rs4402960 in IGF2BP2; and rs13266634 in SLC30A8. In addition, rs7903146 and rs12255372 in TCF7L2; rs5215 and rs5219 in KCNJ11; and rs3856806 and rs1801282 in PPARG were genotyped. The genotype frequencies in the GDM patients were compared with those in the non-diabetic controls.

RESULTS

Compared with controls (men and women combined), GDM was associated with rs7756992 and rs7754840 (OR 1.55, 95% CI 1.34-1.79, p = 4.17 x 10(-9)) in CDKAL1; rs10811661 (OR 1.49, 95% CI 1.29-1.72, p = 1.05 x 10(-7)) in the CDKN2A-CDKN2B region; rs1111875 (OR 1.27, 95% CI 1.09-1.49, p = 0.003), rs5015480, and rs7923837 in HHEX; rs4402960 (OR 1.18, 95% CI 1.01-1.38, p = 0.03) in IGF2BP2; rs13266634 (OR 1.24, 95% CI 1.07-1.43, p = 0.005) in SLC30A8; and rs7903146 (OR 1.58, 95% CI 1.03-2.43, p = 0.038) in TCF7L2. The risk alleles of the SNPs rs7756992 and rs7754840 in CDKAL1; rs10811661 in the CDKN2A-CDKN2B region; and rs1111875, rs5015480 and rs7923837 in HHEX were associated with significant decreases in the insulin AUC during a 100 g OGTT performed at the time of diagnosis of GDM.

CONCLUSIONS/INTERPRETATION

Some of the type 2 diabetes-associated genetic variants that were discovered in the recent GWA studies are also associated with GDM in Koreans.

Electroactive polymer actuator with high response speed through anisotropic surface roughening by plasma etching

Plasma etching was performed to improve displacement and response speed of IPMC actuator through homogeneous roughening and anisotropic surface treatment. We found that the anisotropic surface treatment by plasma etching of Nafion in the pre-treatment process gave the response speed and displacement of resulting IPMC which was 2 times faster and 1.5 times larger than those manufactured by the sandblasting, respectively.

Crystalline amorphous semiconductor superlattice

A new class of superlattice, crystalline amorphous superlattice (CASL), by alternatively depositing two semiconductor materials, is proposed. CASL displays three states depending on the component materials' phase: both polycrystalline phases, both amorphous phases, and one polycrystalline phase while another amorphous phase. Using materials capable of reversible phase transition, CASL can demonstrate reversibility among three states. GeTe/Sb(2)Te(3) CASL has been synthesized and proved by x-ray reflectometry and TEM results. The reversible transition among three states induced by electrical and laser pulse was observed. The changes in the optical absorption edge, electrical resistivity, thermal conductivity, and crystallization temperature as a function of layer thickness are interpreted as quantum or nanoeffects. The unique properties of CASL enable the design of materials with specific properties.

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.

Changes in metabolic syndrome of Korean children and adolescents in the period 1998 to 2001

The aim of this study was to compare the prevalence and pattern of metabolic syndrome in children and adolescents in the interval between the Korean National Health and Nutrition Examination Surveys (KNHANES) in 1998 and 2001. Two nationwide surveys (KNHANES) were conducted in Korea in 1998 and 2001. A stratified multistage probability sampling design was used to ensure representation of the entire Korean population. The National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III)-derived definition was used for the definition of metabolic syndrome. A total of 1763 (mean age+/-SD of 14.6+/-2.8 yr) and 1245 (14.1+/-2.8 yr) Korean children and adolescents in the age range 10-19 yr participated in the studies of 1998 and 2001, respectively. The prevalence of metabolic syndrome in male children and adolescents increased significantly from 5.7% in 1998 to 9.0% in 2001. However, there was no increase in females (5.1% in 1998 and 4.9% in 2001). Of the 5 components of metabolic syndrome, low HDL-cholesterolemia showed the highest increase in males and females during the 3 yr. Hypertriglyceridemia increased next in both genders. In contrast, the proportion of female subjects meeting the fasting glucose criterion decreased over the same period. As dyslipidemia was the principal contributor to the increase in metabolic syndrome in Korean male children and adolescents during the 3 yr, a strategy of dietary pattern change and the encouragement of physical activity should be introduced to these groups at a national level.

Association of polymorphisms in the insulin-degrading enzyme gene with type 2 diabetes in the Korean population

Insulin-degrading enzyme (IDE) is a metalloproteinase which degrades insulin and terminates its action. Homologous deletion of IDE gene resulted in hyperinsulinemia and glucose intolerance in a rat model of type 2 diabetes mellitus. Several genetic association studies examined IDE as a susceptibility gene for type 2 diabetes in European descents. Here we investigated the genetic association of IDE polymorphisms with the risk of type 2 diabetes and its related phenotypes in the Korean population. Among six single nucleotide polymorphisms analyzed, g.-179T>C (OR=1.73, P=0.04), and g.IVS18+99G>A (OR=1.23, P=0.02) revealed borderline association with increased risk of type 2 diabetes. Combining our results with previous data obtained from the European population, g.-179T>C (OR=1.11, P=0.03), and g.IVS24-64A>T (OR=1.18, P=0.005) showed significant association with type 2 diabetes. Haplotype consisting of common alleles of the six polymorphisms was associated with decreased risk of type 2 diabetes (OR=0.82, P=0.02). However, none of the polymorphisms was significantly associated with metabolic phenotypes. We can conclude that variations in IDE might contribute to diabetes susceptibility in the Korean population.

Glutamine preferentially inhibits T-helper type 2 cell-mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A(2) activity in a murine asthma model

BACKGROUND

The non-essential amino acid, l-glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A(2) (cPLA(2)) activity. cPLA(2) has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined.

OBJECTIVE

To investigate the effects of Gln on allergic bronchial inflammation and airway hyperresponsiveness (AHR), and to determine the possible action mechanisms of Gln in a murine model of asthma.

METHODS

cPLA(2) phosphorylation was assessed by immunoprecipitation and Western blotting. Smears of bronchoalveolar lavage cells were stained with Diff-Quik solution for differential cell counting. Airway levels of the proteins [T-helper type-1 (Th1) and Th2 cytokines, and mucin] were measured by ELISA. mRNA expression of cytokines was assessed by real-time RT-PCR. AHR was assessed as a change in airway resistance (RL). Histological studies were performed to assess the levels of mucin and pulmonary inflammation.

RESULTS

Systemic Gln administration inhibited cPLA(2) phosphorylation and its enzymatic activity in the lungs. Additionally, Gln effectively suppressed the key features of Th2-dependent asthmatic features, such as airway eosinophilia, mucus formation, and airway type 2 cytokine production, as well as late AHR.

CONCLUSION

Gln was found to be effective in the suppression of Th2-dependent phenotypes and late AHR, and this effect of Gln appeared to be at least partially attributable to its ability to suppress cLPA(2) activity in the airway. Our results suggest that clinical use of Gln for patients with asthma may be beneficial.

Fulminant type 1 diabetes in Korea: high prevalence among patients with adult-onset type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to investigate the prevalence of fulminant type 1 diabetes and the clinical characteristics of the disease among newly diagnosed Korean patients.

METHODS

Using data retrieved from the Seoul National University Hospital database, we identified all patients newly diagnosed with type 1 diabetes from 1 January 1999 to 31 July 2006. Information on clinical manifestations and laboratory data, including the presence of islet autoantibodies detected at diagnosis, were obtained by reviewing medical records.

RESULTS

We identified 99 patients newly diagnosed with type 1 diabetes. Seven patients (7.1%) fulfilled the criteria for fulminant type 1 diabetes. Among the patients aged > or =18 years at onset, 30.4% had fulminant type 1 diabetes. Patients with this diabetes subtype tested negative for islet autoantibodies, had a higher age of onset (median 28 vs 10 years, p < 0.001) and a markedly shorter duration from onset of hyperglycaemic symptoms to first hospital visit (median 3 vs 30 days, p < 0.001) than patients with non-fulminant type 1 diabetes, and showed trends of increased serum aspartate aminotransferase and amylase levels and a decreased glucagon-stimulated serum C-peptide response.

CONCLUSIONS/INTERPRETATION

In Korea, the prevalence of fulminant type 1 diabetes was 7.1% among all patients newly diagnosed with type 1 diabetes and 30.4% among patients with adult-onset diabetes. The clinical and metabolic characteristics of the patients with fulminant type 1 diabetes were similar to those reported in Japanese studies.

Intraventricular angiolipoma

We report a case of 50-year-old man who was presented with recurrent episodes of left sided hemiparesis. CT scan and MRI brain revealed a large intraventricular fatty lesion. Histopathological examination showed a picture of angiolipoma.

Phacoemulsification using iris hooks and scleral fixation of the intraocular lens in patients with secondary glaucoma associated with lens subluxation

PURPOSE

We described the techniques and results of phacoemulsification using iris hook and scleral fixation of intraocular lens (IOL) in patients with secondary glaucoma associated with lens subluxation.

METHODS

Eight eyes of seven patients with secondary glaucoma associated with lens dislocation, who had undergone the surgery, were retrospectively reviewed.

RESULTS

At a mean of 23.5 months+/-13.6 (SD) after the surgery, the mean best-corrected visual acuity improved from 0.24+/-0.21 to 0.83+/-0.3, and mean intraocular pressure (IOP) was changed from 38.4+/-11.4 to 15.5+/-1.8 mmHg at the final examination. There were no vitreoretinal complications except cystoid macular oedema in one eye.

CONCLUSION

The technique appears to be safe and effective in terms of visual rehabilitation and controlling IOP in patients with secondary glaucoma associated with lens subluxation.

Pseudotumour in the bladder as a complication of total hip replacement: ultrasonography, CT and MR findings

We report a pseudotumour in the urinary bladder following total hip replacement with review of the literature. Pseudotumour in the urinary bladder as a late complication of total hip replacement is an extremely rare condition. In this case, cross-sectional imaging modalities including sonography, CT and MR showed a hypervascular polypoid mass in the urinary bladder and adjacent wall thickening with a band connecting between the mass and the acetabulum. Histopathological diagnosis confirmed acute and chronic inflammation with calcification.

Regulation of adipocyte differentiation by PEGylated all-trans retinoic acid: reduced cytotoxicity and attenuated lipid accumulation

Obesity is major risk factor for many disorders, including diabetes, hypertension and heart disease. Unfortunately, there is a dearth of therapeutic agents available to clinicians for the treatment of obesity. The principal aim of this study was to investigate whether PEGylated all-trans retinoic acid (PRA) can have favorable stability and biological activity in 3T3-L1 preadipocytes as an antiobesity drug. Here, we found that PRA inhibits the process of adipogenesis, including survival of adipocytes and differentiation to mature adipocytes. The results showed that RA nanoparticles (NPs) were prepared by PEGylation; below 200 nm, PRA-NPs were obtained. Moreover, PRA decreased glycerol-3-phosphate dehydrogenase activity in 3T3-L1 preadipocytes by acting with major adipocyte marker proteins such as PPARgamma2, C/EBPalpha and aP2 modulators. Apoptosis, in addition, increased as the level of RA increased from 10 to 20 microM, whereas PRA reduced apoptosis with increasing concentrations. Our data suggest that PRA-NP has potential as an antiobesity drug carrier due to its small particle size and PEGylated core-shell structure. In addition, our results suggest that PRA inhibits the process of adipogenesis and may be developed to treat obesity. Based on these results, PRA is suitable for adipocyte studies, and an enhanced effect of PRA with adipocyte differentiation offers a challenging approach for pharmaceutical applications.

Polymorphisms of KCNJ11 (Kir6.2 gene) are associated with Type 2 diabetes and hypertension in the Korean population

AIMS

Kir6.2 is found in the pancreatic B-cell, cardiac and skeletal muscle and non-vascular smooth muscle. KCNJ11, encoding Kir6.2, has been shown to be associated with both Type 2 diabetes mellitus and cardiovascular disease in several populations. In this study, we investigated whether polymorphisms in KCNJ11 are associated with Type 2 diabetes and other metabolic phenotypes in the Korean population.

METHODS

We sequenced KCNJ11 to identify common polymorphisms using 24 Korean DNA samples. Of the 14 polymorphisms found in KCNJ11, six common ones [genomic sequence (g.)-1709A>T, g.-1525T>C, g.67G>A (E23K), g.570C>T (A190A), g.1009A>G (I337V), and g.1388C>T] were genotyped in 761 Type 2 diabetic patients and in 630 non-diabetic subjects.

RESULTS

All the polymorphic loci in KCNJ11 are in strong linkage disequilibrium in the Korean population and act as one haplotype block. g.67G>A and g.1009A>G were associated with an increased risk of Type 2 diabetes [age, sex, and body mass index (BMI)-adjusted odds ratios (OR) = 1.376 (1.085-1.745), P = 0.008 and 1.411 (1.111-1.791), P = 0.005, respectively], as was one haplotype (A-T-A-C-G-C in the order of polymorphisms as shown above) containing g.67A and g.1009G [OR = 1.359 (1.080-1.709), P = 0.009]. The haplotype (A-T-A-C-G-C) was also strongly associated with hypertension [OR = 1.655 (1.288-2.126), P < 0.001].

CONCLUSIONS

Polymorphisms in KCNJ11 are associated with Type 2 diabetes and also with hypertension in the Korean population.

A new and simple transection knife for study of neurodegeneration and neuroregeneration in animal model

BACKGROUND

The purpose of this study was to design and make a simple, inexpensive brain knife that could produce consistent results following transection in animal model.

MATERIALS AND METHODS

After testing various materials including commercially available products, microelectrode recording needles as used in deep brain stimulation (DBS) surgery were selected as ideal candidates. They were modified to serve as type of wire-knife for the purposes of study. For this study, the major pathway for dopaminergic neuron from substantia nigra to striatum was selected for transection. A total of 40 Sprague-Dawley rats were assigned to 8 groups; normal, 1-4, 6, 8, and 10 weeks post-transection. Degree of cell death was determined and surviving neurons were counted by means of fluorescent microscopic examination, immunohistochemistry involving tyrosine hydroxylase (TH)-immunoreactive staining, and mapping to verify complete transection.

RESULTS

Compared to control, percentage of remaining neurons in each group was 61.3, 36.8, 29.9, 5.1, 5.9, 7.0%, respectively. Completeness of lesion was correlated with the absence of TH-immunoreactivity in the striatum.

CONCLUSION

Our model seems to provide complete cell death in early period after transection with consistent results. Thus, this type of brain knife can be very handy, without any extra cost, in any research model involving transection of fiber bundle for studies on neurodegeneration and neuroregeneration.

Sp1 mediates repression of the resistin gene by PPARγ agonists in 3T3-L1 adipocytes

Resistin is an adipokine related to obesity and insulin resistance. Expression of the resistin gene is repressed by the treatment of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, thiazolidinediones (TZDs). In this study, we investigated the mechanism by which TZDs inhibit the resistin gene expression. Resistin gene expression was decreased by TZD in fully differentiated 3T3-L1 adipocytes, which was abolished after treatment of cycloheximide (a protein synthesis inhibitor). TZD could not repress the expression of the resistin gene in the presence of mithramycin A (an Sp1 binding inhibitor). Sp1 binding site of the resistin promoter (-122/-114bp) was necessary for the repression. Further investigation of the effect of TZDs on the modification of Sp1 showed that the level of O-glycosylation of Sp1 was decreased in this process. These results suggest that PPARgamma activation represses the expression of the resistin gene by modulating Sp1 activity.

Putative association of peroxisome proliferator-activated receptor gamma co-activator 1beta (PPARGC1B) polymorphism with Type 2 diabetes mellitus

AIMS

Peroxisome proliferator-activated receptor gamma co-activator 1beta (PPARGC1B) may play an important role in obesity and Type 2 diabetes mellitus (T2DM). In an effort to identify genetic polymorphisms in potential candidate genes for T2DM, genetic associations of PPARGC1B were examined in a Korean T2DM study.

METHODS

We have sequenced the PPARGC1B, and examined its association with T2DM and diabetic phenotypes in a Korean T2DM study (775 T2DM patients and 316 control subjects) using the TaqMan method. Logistic and multiple regression models were employed to analyse the genetic contributions of polymorphisms. Nineteen polymorphisms were identified in PPARGC1B.

RESULTS

By logistic regression analysis controlling for age and sex as covariates, one non-synonymous single-nucleotide polymorphism (SNP; +102605C>A; Arg292Ser) in exon 5 showed marginal significant associations with the risk of T2DM. The allele frequency of the minor allele ['A (= Ser)' allele of +102605C>A] was lower among T2DM patients (frequency = 0.101) than among control subjects (frequency = 0.135) [P = 0.03, OR = 0.71 (95% CI: 0.51-0.94)]. Furthermore, serum triglyceride level was also associated with this non-synonymous SNP (+102605C>A; Arg292Ser) in exon 5 among controls (P = 0.03 in the dominant analysing model). Serum triglyceride levels [1.46 +/- 0.70 (log-transformed value; 0.12 +/- 0.18)] were lower in individuals who carry one or two copies of minor alleles than among others [1.60 +/- 0.85 (log-transformed value; 0.16 +/- 0.21)].

CONCLUSION

The present study provides, for the first time, information about genetic polymorphisms in PPARGC1B and putative associations of one non-synonymous SNP with the risk of T2DM and serum triglyceride (TG) levels in the Korean population, although this result was not significant after correction for multiple testing.

Genetic diversity of Legionella pneumophila inferred from rpoB and dotA sequences

This study characterised the population structure of Legionella pneumophila by comparing the rpoB (300-bp) and dotA (360-bp) sequences of 267 isolates (18 reference strains, 149 Korean isolates and 100 Japanese isolates). In addition to the six clonal subgroups established previously, four subgroups, P-V to P-VIII, were identified. Subgroupings based on rpoB and dotA sequences were found to correlate with the source of the isolates, and this data may be useful for future epidemiological studies. Fourteen (five Korean and nine Japanese) isolates showed incongruent subgroupings in the rpoB and dotA trees, suggesting that genetic exchange among subgroups, and even among subspecies, may occur frequently in nature.

A rural-urban comparison of the characteristics of the metabolic syndrome by gender in Korea: the Korean Health and Genome Study (KHGS)

The number of cases of the metabolic syndrome is increasing dramatically in Western countries. However, the evaluation of the metabolic syndrome is limited in Asian countries. Thus, our objectives were: 1) to investigate parameters of the metabolic syndrome defined by the National Cholesterol Education Program (NCEP)-Adult Treatment Panel III (ATPIII) in the subjects representing Korean general population and 2) the modification of which factor is most effective in reducing the metabolic syndrome. A total of 10,044 (5024 rural and 5020 urban) Korean men and women in the age range 40-69 yr voluntarily participated in this community-based cross-sectional study (a rural and an urban community was selected). Anthropometric parameters (weight, height, waist and hip circumference and blood pressure), social factors (smoking, alcohol, exercise and education status) as well as biochemical parameters (fasting glucose and insulin, lipids and body composition) were measured. Twenty-six point one per cent of the total subjects were classified as having the metabolic syndrome. Age- and sex-adjusted prevalences were 29.3 and 22.3% in the rural and urban community, respectively (p< 0.01). Abdominal obesity (46.9%) and high blood pressure (45.2%) were major components in the rural community; hypertriglyceridemia (37.6%) and low HDL-cholesterolemia (37.0%) in the urban community. In conclusion, abdominal obesity in the rural community and dyslipidemia in the urban community should be a main subject of intervention, aimed at reducing the prevalence of the metabolic syndrome in Korea. Given the rapid progression of the Korean economy over the past 30 yr, the prevalence of the metabolic syndrome is expected to increase continuously. A strategy to prevent this expected extraordinary event should be conducted at a national level.

Common promoter polymorphism in monocyte differentiation antigen CD14 is associated with serum triglyceride levels and body mass index in non-diabetic individuals

AIMS

Growing evidence supports the hypothesis that chronic low-grade inflammation related to innate immunity may play an important role in the pathophysiology of Type 2 diabetes mellitus (T2DM). The monocyte differentiation antigen CD14 gene (CD14) acts as the receptor for lipopolysaccharide (LPS) and augments monocyte/macrophage inflammatory responses.

METHODS

We have sequenced the gene, including all exons, exon/intron boundaries, and the -1.5 kb of the 5' flanking region. Two common loci (minor allele frequency > 0.05) were genotyped in 775 T2DM patients and 316 control subjects recruited in the Korean T2DM Study.

RESULTS

Eight polymorphisms, including four non-synonymous forms, were identified in CD14. No polymorphisms were found in association with T2DM. However, one common promoter SNP (-260T>C) was significantly associated with both the serum triglyceride level (TG) and body mass index (BMI) in non-diabetic control subjects. Individuals who carried the minor allele (C) had higher TG levels (1.65 +/- 0.81 vs. 1.46 +/- 0.80 mmol/l; P = 0.0007) and BMI (23.96 +/- 3.00 vs. 23.28 +/- 3.22 kg/m(2); P = 0.04) as compared with subjects carrying T/T genotypes.

CONCLUSION

Our data suggest that lipid metabolism and obesity, important pathophysiological elements of T2DM and the metabolic syndrome, are regulated by complex mechanisms that include the CD14 gene polymorphism-mediated genetic propensity to non-specific inflammatory responses.

C-reactive protein level as an independent risk factor of metabolic syndrome in the Korean population. CRP as risk factor of metabolic syndrome

Interrelationship between C-reactive protein (CRP) and metabolic syndrome (MS) was evaluated in a community-based cohort of 9773 Koreans aged 40-69 years. Metabolic syndrome was defined by criteria of the National Cholesterol Education Program. CRP was measured by validated high-sensitivity assay. The median CRP level was 1.4 mg/1, and significantly increased as the number of components of MS increased (P trend <0.001). CRP levels were significantly but marginally correlated with waist circumference (r=0.18), triglyceride (r=0.14), blood pressure (r=0.11), HDL-cholesterol (r=-0.10), and fasting glucose (r=0.09) (all P values<0.01). Odds ratios of the highest quartile of CRP for each component of MS; i.e., waist circumference, triglyceride, glucose metabolism, blood pressure, and HDL-cholesterol were 2.36, 1.79, 1.70, 1.32 and 1.28, respectively. The highest quartile of CRP was independently associated with 1.72-fold increased risk of MS in our logistic regression model adjusted for age, sex, BMI, and smoking. This study demonstrated that CRP is a strong associating factor of MS in Korean population. We recommend further evaluation of CRP levels in the other Asian ethnic groups to establish biological plausibility as the risk factor for MS in all ethnic groups.