Creatinine to Cystatin C Ratio as a Marker of Bone Property in Older Adults: The J-SHIPP Study.

OBJECTIVES: To clarify whether serum creatinine to cystatin C ratio (CCR), a marker of muscle mass and muscle function may be used as a simple marker of bone property. DESIGN: A cross-sectional analysis. SETTING: A general population-based observation study. PARTICIPANTS: 1,606 middle-aged to elderly (≥50 years, mean age: 66.9 ± 7.5 years old) men (n = 642) and post-menopausal women (n = 964). MEASUREMENT: Speed of sound (SOS) at the calcaneal bone was used as a surrogate marker of bone mineral density. The cross-sectional area of the muscle at the mid-thigh was measured using computed tomography. RESULTS: There was significant linear correlation between the quartiles of CCR and SOS (Q1: 1,495 ± 25, Q2: 1,499 ± 24, Q3: 1,507 ± 26, Q4: 1,511 ± 25 m/sec; P < 0.001) even in a sex-separated analysis. This association was independent of major covariates (Q1: ß = -0.126, P < 0.001; Q2: ß = -0.096, P = 0.001; Q3: ß = -0.022; P = 0.412, Q4: reference) and the mid-thigh muscle mass, while creatinine alone or eGFR did not show clear association with SOS. CONCLUSION: The CCR may be used as a simple marker of bone property independently of muscle mass in a general population with preserved renal function.

Durability of protective effect of dulaglutide on pancreatic ß-cells in diabetic mice: GLP-1 receptor expression is not reduced despite long-term dulaglutide exposure.

AIMS: It is well-known that chronic exposure to large amounts of ligand leads to downregulation of its receptor. It is not known, however, whether a GLP-1R agonist downregulates its receptor. For this reason, our study examined whether GLP-1R expression is reduced after long-term exposure to dulaglutide (Dula) in non-diabetic and diabetic mice. METHODS: Seven-week-old male db/db and db/m mice were given either Dula (0.6mg/kg×2/week) or a control vehicle (CTL) for 17 weeks. Various metabolic parameters, such as glucose-stimulated insulin secretion (GSIS), insulin and TG content in islets, were evaluated after the intervention. ß-cell-related gene expression was also analyzed by real-time RT-PCR. RESULTS: In db/m mice, GLP-1R expression in ß-cells did not decrease, not even after long-term administration of Dula, compared with control mice, while GLP-1R expression in 24-week-old db/db mice treated with Dula was augmented, rather than downregulated, compared with 24-week-old CTL db/db mice. This was probably due to improved glycaemic control. In db/db mice treated with Dula, food intake and blood glucose levels were significantly decreased up to 24 weeks of age compared with CTL db/db mice, and their expression levels of various ß-cell-related genes, insulin content and GSIS were also enhanced. In contrast, oxidative and endoplasmic reticulum stress, inflammation, fibrosis and apoptosis were suppressed with Dula treatment. CONCLUSION: Dula exerts beneficial effects on glycaemic control and has long-lasting protective effects on pancreatic ß-cells. GLP-1R expression levels were not reduced at all in non-diabetic as well as diabetic mice despite long-term dulaglutide exposure.

Facial pigmentation as a biomarker of carotid atherosclerosis in middle-aged to elderly healthy Japanese subjects.

BACKGROUND/PURPOSE: Perceived age may be a better predictor of mortality rate than chronological age. We have demonstrated that perceived age was a significant biomarker for carotid atherosclerosis in Japanese. However, it remains to be determined which skin parameter is associated with atherosclerosis. The purpose of this study is to analyze the relationship between 10 facial skin-aging parameters and atherosclerosis in 169 middle-aged to elderly Japanese women who participated. METHODS: Facial photographs were taken under a shadowless lamp from three directions using a high-resolution digital camera. The digital images of each subject were analyzed using computer software and various parameters of skin aging such as pigmentation, wrinkles, and skin color were quantified. Carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV) were measured as indices for atherosclerosis. RESULTS: Facial pigmentation showed a significant correlation with carotid IMT, even after correction for age (r = 0.13, P = 0.03), and with visceral fat area. Stepwise regression analysis indicated that facial pigmentation was associated with carotid IMT via visceral fat area. CONCLUSION: Facial pigmentation may be a useful biomarker for carotid atherosclerosis in Japanese women.

Usefulness of mandibular third molar coronectomy assessed through clinical evaluation over three years of follow-up.

The aim of this study was to investigate the 3-year morbidity of coronectomy of the lower third molar and to monitor the behaviour and migration pattern of the retained roots postoperatively. A total of 92 patients (111 teeth) who had undergone a coronectomy between October 2005 and July 2009 were investigated. Patients were followed up at 3 months and 1, 2, and 3 years for clinical evaluation and dental computed tomography imaging of the coronectomy sites. In total, 10 cases (9%) required tooth root extraction within the 3 years after coronectomy. In seven of them, the distal pocket of the lower second molars remained connected to the roots within the first year. Of the cases in whom a pocket did not remain at an early stage, none showed peri-apical lesions on transmission images of the retained roots in the apical area, which usually result from necrosis of the pulp. Root migration increased in the first 2 years after coronectomy but stabilized between the second and third years. In addition, a significant difference was noted in root migration between patients of different ages and sex. Retained roots after coronectomy in the lower third molars led to no complications in terms of infection or the development of pathologies within the first 3 years postoperatively.

Missense variants of the alanine: glyoxylate aminotransferase 2 gene correlated with carotid atherosclerosis in the Japanese population.

Alanine:glyoxylate aminotransferase 2 (AGXT2; EC 2.6.1.44) degrades asymmetric dimethylarginine (ADMA), a competitive inhibitor of nitric oxide (NO) synthase. Increased ADMA, reduced NO, and hypertension are shown in Agxt2 knockout mice. There are four single nucleotide polymorphisms (rs37370, rs37369, rs180749, and rs16899974) with which AGXT2 activity changes in humans and may be related to vulnerability of vascular sclerosis. To examine the relationship between them, we studied the functional haplotypes of the AGXT2 gene and decided their relationship with arteriosclerotic changes via carotid intima-media thickness (carotid IMT) in Japanese subjects. Genotyping of those polymorphisms and the carotid IMT in 1,426 Japanese subjects were then evaluated. Subjects with C-A-A-A haplotype (rs37370, rs37369, rs180749, rs16899974) showed low AGXT2 activity (P<0.0001; Pearson’s correlation coefficients: 0.497). The C-A-A-A haplotype was significantly associated with mean carotid IMT (P=0.049) and max carotid IMT (P=0.004). Subjects with two C-A-A-A haplotypes exhibited thicker mean carotid IMT (P=0.022) and maximum carotid IMT (P=0.001). In multiple regression analysis, subjects with two C-A-A-A haplotypes were independently and positively associated with mean carotid IMT (P=0.02) and maximum IMT (P=0.005) after correction. There was a significant correlation between the functional variants in the AGXT2 gene and carotid IMT in Japanese. The AGXT2 genotype may be an important factor underlying atherosclerosis.

Association of Chr17q25 with cerebral white matter hyperintensities and cognitive impairment: the J-SHIPP study.

BACKGROUND AND PURPOSE: A recent genome-wide association study has successfully identified several genetic variations in the Chr17q25 locus as susceptible genotypes for white matter hyperintensities. We report the first replication study in subjects of non-European origin. We also investigated possible associations with other asymptomatic cerebrovascular diseases and cognitive function. METHODS: Study subjects were 1190 general Japanese persons (66.0 ± 8.9 years old). Asymptomatic cerebrovascular damage, including lacunar infarctions, microbleeds, periventricular hyperintensity and deep and subcortical white matter hyperintensity (DSWMH), was evaluated by brain magnetic resonance imaging. RESULTS: A polymorphism rs3744028 was significantly associated with DSWMH grade (P = 0.015) but not periventricular hyperintensity, lacunar infarction, and microbleeds. Although age, hypertension, insulin resistance, B-type natriuretic peptide, and carotid atherosclerosis were also correlated with DSWMH, association of the genotype was independent of these environmental risk factors. In contrast, the risk allele had a protective effect against reduced cognitive function. CONCLUSION: Susceptibility of the 17q25 locus may be conserved beyond ethnic differences. Genetic variants may have bipolar effects on brain histological and functional changes.

Vildagliptin preserves the mass and function of pancreatic ß cells via the developmental regulation and suppression of oxidative and endoplasmic reticulum stress in a mouse model of diabetes.

AIM: We investigated the molecular mechanisms by which vildagliptin preserved pancreatic ß cell mass and function. METHODS: Morphological, biochemical and gene expression profiles of the pancreatic islets were investigated in male KK-A(y) -TaJcl(KK-A(y) ) and C57BL/6JJcl (B6) mice aged 8 weeks which received either vildagliptin or a vehicle for 4 weeks. RESULTS: Body weight, food intake, fasting blood glucose, plasma insulin and active glucagon-like peptide-1 were unchanged with vildagliptin treatment in both mice. In KK-A(y) mice treated with vildagliptin, increased plasma triglyceride (TG) level and islet TG content were decreased, insulin sensitivity significantly improved, and the glucose tolerance ameliorated with increases in plasma insulin levels. Furthermore, vildagliptin increased glucose-stimulated insulin secretion, islet insulin content and pancreatic ß cell mass in both strains. By vildagliptin, the expression of genes involved in cell differentiation/proliferation was upregulated in both strains, those related to apoptosis, endoplasmic reticulum stress and lipid synthesis was decreased and those related to anti-apoptosis and anti-oxidative stress was upregulated, in KK-A(y) mice. The morphological results were consistent with the gene expression profiles. CONCLUSION: Vildagliptin increases ß cell mass by not only directly affecting cell kinetics but also by indirectly reducing cell apoptosis, oxidative stress and endoplasmic reticulum stress in diabetic mice.

Prognostic significance of FTO genotype in the development of obesity in Japanese: the J-SHIPP study.

OBJECTIVE: Susceptibility of fat mass and obesity-associated (FTO) gene polymorphisms to obesity has been reported in various populations. Polymorphisms in the melanocortin 4 receptor (MC4R) gene were recently explored as another susceptible locus. However, prognostic significance of these genetic variations has not been fully elucidated. Here, we investigated the involvement of FTO rs9939609 and MC4R rs17782313 polymorphisms in the development of obesity. Association with type 2 diabetes mellitus (T2DM) was also investigated. SUBJECTS: We analyzed 2806 community-dwelling middle-aged to elderly subjects (61+/-14 years). Clinical parameters were obtained from the subjects' personal health records, evaluated at their annual medical check-up. RESULTS: FTO genotype was significantly associated with current body mass index (BMI; TT 23.2+/-3.2, TA 23.7+/-3.2, AA 24.4+/-3.2 kg m(-2), P=2.5 x 10(-6)) and frequency of obesity (26.6, 32.0, 43.0% respectively, P=2.0 x 10(-4)). Age- and sex-adjusted odds ratio for obesity was 1.30 (P=0.004) in TA and 2.07 (P=0.002) in AA genotype. During the 9.4 years comprising the follow-up period, 214 new cases of obesity were diagnosed among 1718 subjects whose retrospective data were available. A allele frequency of the FTO genotype was significantly higher in subjects who developed obesity (22.2, 15.8%, P=0.001), Age-, sex- and initial BMI-adjusted odds ratio for the development of obesity was 1.46 (95% confidence interval, 1.04-2.04) (P=0.031). However, association studies and meta-analysis of T2DM did not actively support the involvement of FTO genotype. No significant differences were observed between the MC4R genotype and BMI (P=0.015), and the frequency of obesity (P=0.284). CONCLUSION: FTO genotype is an independent risk factor for future development of obesity.

Clinical usefulness of the second peak of radial systolic blood pressure for estimation of aortic systolic blood pressure.

Central aortic blood pressure (BP), obtained from radial arterial waveform using the transfer function method (TFM), has been shown to have prognostic value independently of brachial BP. In this study, the relationship between peripheral systolic BP (SBP) and aortic SBP was evaluated. We further investigated whether TFM-derived aortic SBP can be estimated by information obtained from the radial waveform. The radial waveform was analysed to obtain the first peak of radial SBP (SBP1), second peak of radial SBP (SBP2), radial augmentation index (AI) (radial (SBP2-DBP)/(SBP1-DBP) x 100 and aortic SBP and AI using TFM in 233 subjects in the supine position. Measurements were repeated after changing position to the prone position. The constructed equation was validated in 149 community residents with different backgrounds. Radial SBP2 was closer to TFM-derived aortic SBP compared with brachial SBP. TFM-derived aortic SBP was approximated by the equation: aortic SBP=18.9-radial SBP2-0.03 x HR-0.214 x radial AI (r2=0.992). The equation was also applicable to predicting aortic SBP in the prone position as well as in different populations (mean difference between predicted aortic SBP and TFM-derived aortic SBP: -0.01+/-1.34 and 1.05+/-1.47 mm Hg, respectively). Radial arterial waveform analysis can be used for estimation of TFM-derived aortic SBP.

Angiotensin-converting enzyme (ACE) and ACE2 levels in the cerebrospinal fluid of patients with multiple sclerosis.

BACKGROUND: We reported a reduction in the levels of angiotensin II in cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS). OBJECTIVE AND METHODS: To clarify the mechanism underlying this reduction, we assayed angiotensin-converting enzyme (ACE) and ACE2 concentrations along with angiotensin II concentrations in CSF samples from 20 patients with MS and 17 controls with non-neurological diseases. RESULTS: ACE levels were significantly elevated in patients with MS compared with controls (48.42 +/- 4.84 vs 44.71 +/- 3.9 pg/mL), whereas ACE2 levels were significantly reduced (2.56 +/- 0.26 vs 2.78 +/- 0.24 pg/mL), acting toward a normalization of angiotensin II levels. CONCLUSION: These results further indicate an alteration of the intrathecal renin-angiotensin system in patients with MS.

Reduction of angiotensin II in the cerebrospinal fluid of patients with multiple sclerosis.

We previously demonstrated that angiotensin II acts as a crucial neuroprotective factor after neural injury through angiotensin II type-2 (AT2) receptor signaling. Although the pathway is known to play an important role in the development of experimental autoimmune encephalomyelitis, cerebrospinal fluid (CSF) angiotensin II levels in patients with multiple sclerosis (MS) have never been studied. To clarify the significance of angiotensin II in MS, we assayed angiotensin II concentrations using an established enzyme-linked immunoabsorbent assay in CSF samples from patients with MS (n = 21), patients with inflammatory neuropathies (IN) (n = 23) and control individuals who did not have either of the neurological diseases or any other disease that might affect the angiotensin II levels in the CSF (control) (n = 24). Angiotensin II levels in the CSF were 3.79 +/- 1.54 pg/ml in the MS group, 5.13 +/- 2.27 pg/ml in the IN group and 6.71 +/- 2.65 pg/ml in the control group. The angiotensin II levels in the CSF of the MS group were significantly lower than in the control group (p = 0.00057). Angiotensin II concentration in the CSF tended to have a negative correlation with the Kurtzke's Expanded Disability Status Scale scores during MS relapse (p = 0.0847). These findings suggest that reduced levels of intrathecal angiotensin II may be related to the abnormal neural damage and repair processes in MS.

Comparative aspects on the role of polypyrimidine tract-binding protein in internal initiation of hepatitis C virus and picornavirus RNAs.

We compared the effects of polypyrimidine tract-binding protein (PTB) on hepatitis C virus (HCV genotype IIa), encephalomyocarditis virus (EMCV) and poliovirus internal ribosome entry site (IRES) activities in vitro. It bound strongly to EMCV IRES, but weakly to PV and HCV RNAs. PV IRES showed the strongest dependency to PTB and it showed less than one-tenth of IRES activity after the immuno-depletion of PTB from HeLa S10 lysate with pre-coated anti-PTB IgG beads, comparing to the normal IgG beads-treated S10 lysate. EMCV IRES activity was approximately 40% of that of normal control after PTB depletion. Especially, HCV IRES activity was approximately 95%, and most weekly affected by the depletion of PTB. Repletion of PTB to depleted S10 lysate restored activities of PV and EMCV IRESs. The data suggest that PTB plays an important role in picornaviral IRESs, but not in HCV IRES.

Characterization of hypervariable region in hepatitis C virus envelope protein during acute and chronic infection.

Hepatitis C virus (HCV) causes persistent infection in most patients. To clarify the mechanisms underlying establishment of this persistent infection, nucleotide sequences of the E1/E2 region were characterized in 5 patients with acute and chronic HCV infection. We used direct DNA sequencing methods to identify the major sequence of HCV in each patient. Each HCV genome displayed a high frequency of nucleotide sequence variation in the hypervariable region (HVR) of E2. However, patient-specific conserved nucleotide sequences were identified in the E1/E2 region during the course of infection and conserved the higher-order protein structure. In the acute phase HCV infection, amino acid substitution in HVR-1 as the monthly rate of amino acids substitution per site (%) between each point exceeded 10.2%. In the chronic phase HCV infection, a significantly lower rate of amino acid substitution was observed in patients. The host immune responses to HVR-1 of each HCV isolates from all clinical courses were characterized using synthetic peptides and ELISA. One chronic patient serum (genotype 1b) did not react at all to its own HVR-1 peptides, however another patient (genotype 2b) reacted to all clinical course. These results indicated that HVR-1 might not always exhibit neutralizing epitopes of HCV infection. The sequence variation in HVR-1 may instead indicate the existence of various clones in acute phase infection and the adaption of these clones is thought to have caused persistent and chronic infection in each patient.

Expression and purification of recombinant swine interleukin-4.

The swine interleukin-4 (SwIL-4) cDNA was cloned by RT-PCR. It was expressed using an expression vector pQE30 in E. coli, a baculovirus AcNPV vector pVL1392 in insect cells, and a pCAGGS vector in mammalian cells. The rSwIL-4 proteins expressed from bacteria and insect cells were purified using a chelating affinity column and a mAb-coupled immunoaffinity column. The amount of the products and their bioactivities were compared. All recombinant cytokines were efficiently reacted with the specific antibodies and the molecular weight of rSwIL-4 was approximately 16 kDa in E. coli, 15 and 18 kDa in insect cells, and 15 and 20 kDa in mammalian cells. Variations of molecular weight observed in insect and mammalian cells were probably due to different modification ways of glycosylation. All these recombinant proteins retained their antigenicity and were biologically active in inducing human TF-1 cell proliferation in vitro. The simple purification method will make it possible to evaluate the in vitro and in vivo effects of IL-4 in pigs.

Expression and characterization of the recombinant swine interleukin-6.

The swine interleukin-6 (SwIL-6) cDNA was cloned by RT-PCR and each expression system of recombinant SwIL-6 in Escherichia coli, insect cells, and mammalian cells was developed. Recombinant SwIL-6 produced in bacteria was applied for generation of the polyclonal antibodies. The rSwIL-6 was purified from supernatant of insect cells with a Q-sepharose or anti-SwIL-6 monoclonal antibody based immunoaffinity column. The antibodies showed that the molecular weight of rSwIL-6 was approximately 26kDa in E. coli, 25, 26, 30kDa in insect cells, and 26 and 30kDa in mammalian cells. These variations of molecular weight were probably due to the different modifications of glycosylation. All these recombinant proteins retained the antigenicity and biological activity on 7TD1 mouse cells.

Establishment of swine interleukin-6 sandwich ELISA.

We established a sandwich enzyme-linked immunosorbent assay (ELISA) for swine interleukin-6 (SwIL-6), which was applied for detection of SwIL-6 in vitro and in vivo. Anti-SwIL-6 rabbit- and goat-polyclonal antibodies, and monoclonal antibody (mAb) were prepared, conforming that all of the antibodies were reactive with recombinant SwIL-6 by Western blotting and indirect ELISA. A sandwich ELISA was developed using the mAb as a capture antibody and biotinylated goat-polyclonal antibody as a detection antibody. The detection limit of the sandwich ELISA for rSwIL-6 was 49pg/ml and did not show cross-reactivity with swine IL-1b, IL-4, IL-8, IL-18, IL-12, and IFN-g. Using the ELISA, SwIL-6 was detected in culture medium of the monocytes stimulated with PHA-P and PMA, and the plasma or the bronchoalveolar lavage fluid (BALF) of pigs experimentally infected with Actinobacillus pleuropneumoniae or Mycoplasma hyopneumoniae. This ELISA for SwIL-6 may be useful for understanding the role of this cytokine in various swine diseases.

The effect of recombinant swine interleukin-4 on swine immune cells and on pro-inflammatory cytokine productions in pigs.

The in vitro effect and the in vivo influence of recombinant swine IL-4 (rSwIL-4) were characterized in various swine cells and in nursery pigs on LPS-induced endotoxic shock and pro-inflammatory cytokine productions. In in vitro experiment, the rSwIL-4 induced a proliferation of CD4 positive T cells in mitogen-prestimulated peripheral blood mononuclear cell (PBMC). In addition, the rSwIL-4, which was produced from insect cells, promoted the differentiation of monocytes into immature dendritic cells in combination with granulocyte macrophage-colony stimulating factor (GM-CSF). Furthermore, the rSwIL-4 successfully suppressed the LPS-induced secretion of TNF-alpha, IL-1alpha, IL-6, IL-8, and IL-18 from swine alveolar macrophages when rSwIL-4 was treated at the same time with LPS. In in vivo experiment in nursery pigs, subcutaneous pretreatment of rSwIL-4, which was produced from baculovirus expression system, enhanced the severity of respiratory failure with endotoxic shock, and increased the production of TNF-alpha and IL-18 in response to inoculation with LPS. These results indicate that the rSwIL-4 is biologically active in both in vitro and in vivo treatments. Depending on the administration time, pro-inflammatory cytokine productions by IL-4 can cause either inhibitory or stimulatory regulation.

Involvement of apoptosis in syncytial cell death induced by canine distemper virus.

The Yanaka strain, a field isolate of Canine distemper virus (CDV), caused extensive syncytial cytopathic effects (CPEs) followed by cell death in vitro. Syncytium formation is an important aspect of CDV pathogenicity, but the mechanism of the fusion-induced cell death is still not understood. In this study, the involvement of apoptosis in the CDV-induced CPE was investigated. We also examined apoptosis in cells infected with a persistent strain of CDV, the Yanaka-BP strain derived from the Yanaka strain, because this strain does not cause obvious CPE. DNA laddering together with Terminal transferase dUTP nick endlabeling (TUNEL) assay indicated that the Yanaka strain infection, but not the Yanaka-BP infection induced apoptosis. In addition, flow cytometric analysis similarly indicated that the Yanaka-BP strain induced apoptosis significantly less frequently than the Yanaka strain did. Thus, absence of apoptosis may be implicated in the CPE and establishment of persistent CDV infection.

Characterization of specific antibodies and the establishment of sandwich ELISA and ELISPOT systems for swine IL-4.

We produced four monoclonal antibodies (mAb) and two polyclonal antibodies using the purified cytokine expressed in bacteria and characterized them. Specific binding of each of the mAb and polyclonal antibodies to recombinant swine IL-4 (rSwIL-4) purified from Escherichia coli and baculovirus was demonstrated in an indirect ELISA and/or in western blotting. We established a sandwich enzyme-linked immunosorbent assay (ELISA) for measuring concentration of SwIL-4 in biological samples and established an enzyme-linked immunospot (ELISPOT) assay for detecting IL-4-secreting cells using a mAb and a polyclonal IgG from goat. The detection limit of the sandwich ELISA for SwIL-4 was 78 pg/ml. Using sandwich ELISA, SwIL-4 was detected in the bronchoalveolar lavage fluid (BALF) of pigs experimentally infected with Mycoplasma hyopneumoniae and could quantitate in supernatants of mitogen-stimulated PBMC culture. The ELISPOT system is useful for the detection of IL-4 producing cells in swine PBMC culture.