Association of weight change in different periods of adulthood with risk of type 2 diabetes in Japanese men and women: the Japan Public Health Center-Based Prospective Study

BACKGROUND

Few studies have examined the impact of weight change in different periods of lifetime on type 2 diabetes risk, and the association of weight loss with type 2 diabetes is unclear. We prospectively investigated the association of weight change since age 20 y and that during middle-to-late adulthood with the incidence of type 2 diabetes.

METHODS

Subjects were 52,014 men and women aged 45-75 y who participated in the Japan Public Health Center-Based Prospective Study and had no history of diabetes. ORs of self-reported physician-diagnosed type 2 diabetes for weight change between age 20 y and baseline survey (mean age 50.6 y) and during 5 y between baseline and second surveys were estimated using logistic regression analysis.

RESULTS

During the 5-year period following 5-year survey, 989 newly diagnosed cases of type 2 diabetes were self-reported. Weight gain from age 20 y was associated with an increased risk of type 2 diabetes. The multivariate-adjusted OR (95% CI) for a weight gain of ≥5 kg versus a stable weight were 2.61 (2.11 to 3.23) in men and 2.56 (1.95 to 3.35) in women. A weight gain of ≥5 kg over the 5-y following the baseline survey was also associated with an increased risk in women. No association with weight loss was observed for either period.

CONCLUSIONS

These results suggest that long-term weight gain from early adulthood to middle-age increases risk of type 2 diabetes in men and women and that risk is further enhanced by weight gain in later life in women.

Polyamine-promoted autoactivation of plasma hyaluronan-binding protein

BACKGROUND

Plasma hyaluronan-binding protein (PHBP), a protease implicated in extracellular proteolysis, consists of multiple domains: an N-terminal region (NTR), three epidermal growth factor (EGF)-like domains, a kringle domain, and a protease domain. PHBP circulates as a single-chain proenzyme (pro-PHBP), which is converted to an active, two-chain form through autoproteolysis.

OBJECTIVE

To understand the mechanism of autoactivation. Here, we report that polyamine induces the formation of pro-PHBP autoactivation complex, in which an intermolecular interaction between NTR and the third EGF-like domain (E3) plays a role.

METHODS

Using a series of pro-PHBP mutants that partially lack functional domains, polyamine-induced pro-PHBP autoactivation was investigated in terms of enzyme activity, protein interaction, and inhibition by carminic acid, an anthraquinone compound identified in this study.

RESULTS

Polyamine enhanced intermolecular binding of pro-PHBP, but not of mutant pro-PHBP that partially lacked NTR (DeltaN). Carminic acid inhibited intermolecular pro-PHBP binding and specifically abolished polyamine-induced autoactivation. NTR bound to pro-PHBP and DeltaN, but its binding was minimal to a mutant that lacked E3. The NTR-DeltaN binding was inhibited by a combination of polyamine and carminic acid, but each compound alone was ineffective.

CONCLUSIONS

We infer from the data that (i) polyamine modulates intramolecular NTR-E3 interaction to allow intermolecular binding between NTR and E3 in another pro-PHBP molecule to form an autoactivation complex, and (ii) carminic acid inhibits polyamine-modulated intermolecular NTR-E3 binding. Polyamine concentrations are higher in cells and tissues with inflammation and malignancy. Polyamine leakage from legions through cell death or tissue injury may account for physiologically relevant pro-PHBP activation.

Body iron store as a predictor of oxidative DNA damage in healthy men and women

While iron plays an important role in many cellular functions, excess iron storage induces DNA damage by generating hydroxyl radicals and thus promotes carcinogenesis. However, it remains unclear whether body iron levels that are commonly observed in a general population are related to oxidative DNA damage. We examined the association between serum ferritin concentrations and levels of urinary 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of systemic oxidative DNA damage and repair, in 528 Japanese men and women aged 21-67 years. Men had much higher ferritin levels than in women, and the levels were significantly greater in women aged 50 years or older than in women aged less than 50 years. Urinary 8-OHdG concentrations were significantly and positively associated with serum ferritin levels in all the subgroups. The Spearman rank correlation coefficients were 0.47, 0.76, and 0.73 for men overall, women aged less than 50 years, and women aged 50 years or older, respectively. These associations were materially unchanged after adjustment for potential confounding variables. In men, a more pronounced association was observed in nonsmokers than in smokers. Our results suggest body iron storage is a strong determinant of levels of systemic oxidative DNA damage in a healthy population.

Serum folate and homocysteine and depressive symptoms among Japanese men and women

BACKGROUND/OBJECTIVES

Folate and homocysteine have been implicated to have a role in depression. However, results of epidemiologic studies on this issue have been inconsistent. The objective of this study was to clarify the association between serum folate and homocysteine concentrations and depressive symptoms in Japanese adults.

SUBJECTS/METHODS

We analyzed cross-sectional data for 530 municipal employees (313 men and 217 women), aged 21-67 years, who participated in a health survey at the time of periodic checkup. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Logistic regression analysis was used to estimate odds ratios of depressive symptoms (CES-D scale scores of >or=16) with adjustment for potential confounding variables.

RESULTS

In total, 113 men (36.1%) and 79 women (36.4%) had depressive symptoms. A higher serum folate was associated with a decreased prevalence of depressive symptoms in men. The multivariate-adjusted odds ratios (95% confidence interval) of depressive symptoms for the lowest to highest quartiles of serum folate were 1.00 (reference), 0.53 (0.27-1.03), 0.33 (0.16-0.68) and 0.51 (0.25-1.03), respectively (trend P=0.03). Furthermore, the data suggested a positive association between serum homocysteine and depressive symptoms in men (trend P=0.06). In women, neither folate nor homocysteine was associated with depressive symptoms.

CONCLUSIONS

Low serum folate may be related to an increased prevalence of depressive symptoms in Japanese men.

Fasting plasma glucose and 5-year incidence of diabetes in the JPHC diabetes study - suggestion for the threshold for impaired fasting glucose among Japanese

To determine the optimal fasting plasma glucose (FPG) cut-off value which effectively identifies high risk subjects for type 2 diabetes in Japanese, we conducted a population-based prospective study on diabetes as part of the Japan Public Health Center-based Prospective Study and estimated the 5-year incidence of diabetes. The subjects of the analysis of this study were 2,207 Japanese aged 51-70 at baseline from whom a fasting blood sample was collected in both the baseline and the 5-year follow-up surveys and who completed the questionnaires at both times. Diabetes was defined as an FPG value > or = 126 mg/dL (7.0 mmol/L) and/or self-reported diabetes. A total of 125 subjects developed diabetes during the 5 years after the baseline survey, and the incidence rate for a baseline FPG value of 95-99, 100-104, 105-109, 110-114, 115- 119, and 120-125 mg/dL was 6.1, 11.5, 30.3, 52.6, 86.4, and 115.2 per 1,000 person-years, respectively. The results of receiver operating characteristic curve analysis suggested that an FPG value of 102 mg/dL (5.67 mmol/L) was optimal for predicting diabetes during the next 5-years. The cut-off value was similar in both genders and in the 51- to 60-year-old group and 61- to 70-year-old group. Use of hemoglobin A(1c) level > or = 6.1% for an additional diagnostic criterion resulted in a small increment in incidence, but the cut-off value for predicting diabetes was almost the same (101 mg/dL). The results of this study suggested that the cut-off FPG value should be lowered in terms of prediction of type 2 diabetes among Japanese populations.

Visceral fat area and markers of insulin resistance in relation to colorectal neoplasia

OBJECTIVE

Although abdominal obesity and related metabolic abnormalities are hypothesized to promote colorectal carcinogenesis, direct confirmation of this effect is required. Here, we examined the relation of early-stage colorectal neoplasia to visceral fat area and markers of insulin resistance.

RESEARCH DESIGN AND METHODS

Subjects were participants in a comprehensive health screening conducted at the Hitachi Health Care Center, Ibaraki, Japan. During a 3-year period (2004-2007), a total of 108 patients with early-stage colorectal neoplasia, including 22 with early cancer, were identified among individuals who received both colorectal cancer screening and abdominal computed tomography scanning. Three control subjects matched to each case subject were randomly selected from those whose screening results were negative. Conditional logistic regression analysis was used to examine the association of measures of obesity and markers of insulin resistance with colorectal neoplasia, with adjustment for smoking and alcohol drinking.

RESULTS

Visceral fat area, but not subcutaneous fat area, was significantly positively associated with colorectal cancer, with odds ratios (95% CI) for the lowest to highest tertile of visceral fat area of 1 (reference), 2.17 (0.45-10.46), and 5.92 (1.22-28.65), respectively (P(trend) = 0.02). Markers of insulin resistance, particularly fasting glucose, were also positively associated with colorectal cancer risk. In contrast, no associations were observed for colorectal adenomas.

CONCLUSIONS

These results suggest that visceral adipose tissue accumulation and insulin resistance may promote the development of early-stage cancer but not adenoma in the colorectum.

Small interfering RNA targeting CD81 ameliorated arthritis in rats

CD81 belongs to a family of cell-surface protein (tetraspanin) known as one of the up-regulated elements in rheumatoid arthritis synoviocytes. In this study, the therapeutic effect of small interfering RNA targeting CD81 (siCD81) was examined by in vivo electroporation method. Treatment with siCD81 significantly ameliorated paw swelling of collagen-induced arthritic (CIA) rats. In histological examination, hypertrophy of synovium, bone erosion, and degeneration of articular cartilage were milder in rats treated with siCD81 than in the control group and the non-specific siRNA group. Expression of synoviolin, a rheumatoid regulator, was suppressed by siCD81. Thus, therapeutic intervention by targeting CD81 may be used in the treatment of rheumatoid arthritis.

Role of uncoupling protein 1 in the anti-obesity effect of beta3-adrenergic agonist in the dog

We have reported that chronic treatment with beta3-adrenoceptor agonists reduces body fat content and induces the expression of mitochondrial thermogenic uncoupling protein 1 (UCP1) in adipose tissue in the dog. To evaluate the role of UCP1 in the anti-obesity effect of the agonists, we isolated adipocytes from subcutaneous fat pad of beagles before and after a 2-week treatment with AJ-9677, a specific beta3-adrenoceptor agonist, and examined their thermogenic activity in vitro. Histological and protein analysis revealed that adipose tissues before the treatment were composed of unilocular cells filled with a single large droplet, while the tissues after the treatment contained many smaller and some multilocular adipocytes expressing UCP1 and abundant mitochondrial proteins. Before the treatment, oxygen consumption rate was very low and did not change even when the cells were stimulated by AJ-9677. Two-week AJ-9677 treatment increased basal oxygen consumption rate by 7-fold, and produced a clear responsiveness to AJ-9677 stimulation. Thus, chronic treatment with AJ-9677 induced UCP1 in adipocytes, where oxygen consumption increased in response to AJ-9677 stimulation. It was suggested that UCP1-dependent energy expenditure in adipose tissue contributes to the anti-obesity effect of beta3-adrenoceptor agonist in dogs.

Proliferation and apoptosis of tumour cells before and after neoadjuvant therapy for high-grade extremity sarcomas: divergent associations with tumour response and prognosis

AIMS

To evaluate proliferation and apoptosis in high-grade sarcomas of the extremities before and after preoperative radio-hyperthermo-chemotherapy (RHC) and to determine the relationship between these parameters and treatment outcomes.

METHODS AND RESULTS

Pre- and post-RHC specimens of 41 soft tissue and bone tumours were immunohistochemically stained for minichromosome maintenance protein (MCM) 2 and caspase 3 as proliferation and apoptosis markers, respectively, based on a preliminary study comparing them with conventional markers. Indices were calculated as a percentage of positive cells by counting tumour cells in the most frequently labelled areas. MCM2, caspase 3 and MCM2/caspase 3 (growth) indices were 45.3 +/- 21.9%, 4.1 +/- 7.1% and 82.9 +/- 104.5, respectively, in pre-RHC specimens and 35.4 +/- 30.8%, 39.2 +/- 34.6% and 5.3 +/- 11.7, respectively, in post-RHC specimens. Response scores showed positive correlation with pre-RHC MCM2 and post-RHC caspase 3 indices, inverse correlation with post-RHC MCM2 and post-RHC growth indices and no correlation with prognosis. Multivariate analysis revealed high pre-RHC MCM2 and high post-RHC growth indices as significant unfavourable prognostic factors.

CONCLUSIONS

High proliferative activity in untreated sarcoma may predict good response to neoadjuvant therapy, but poor prognosis, whereas a high growth index, i.e. high proliferation:apoptosis ratio in a post-neoadjuvant therapy tumour specimen may indicate poor response and poor prognosis.

Lysophosphatidylcholine induces neuropathic pain through an action of autotaxin to generate lysophosphatidic acid

Lysophosphatidic acid receptor (LPA(1)) signaling initiates neuropathic pain and several pathological events in a partial sciatic nerve injury model. Recently, we reported that lysophosphatidic acid (LPA) induces neuropathic pain as well as demyelination and pain-related protein expression changes via LPA(1) receptor signaling. Lysophosphatidylcholine (LPC), also known as lysolecithin, which is hydrolyzed by autotaxin/ATX into LPA, induces similar plastic changes. Here, we attempted to clarify whether ATX and LPA(1) receptor signaling is involved in the LPC-induced neuropathic pain. In wild-type mice, a single intrathecal (i.t.) injection of LPC induced mechanical allodynia and thermal hyperalgesia 2 days after injection; this persisted for 7 days at least. On the other hand, LPC-induced mechanical allodynia and thermal hyperalgesia were completely abolished in mice lacking an LPA(1) receptor gene. Furthermore, the LPC-induced response was also significantly, but partially reduced in heterozygous mutant mice for the ATX gene. These findings suggest that intrathecally-injected LPC is converted to LPA by ATX, and this LPA activates the LPA(1) receptor to initiate neuropathic pain.

Blockade of CD40/CD40 ligand interactions attenuates skin fibrosis and autoimmunity in the tight-skin mouse

OBJECTIVE

To assess the association of CD40/CD40 ligand (CD40L) interactions with the development of skin fibrosis and autoimmunity in tight-skin (TSK/+) mouse, which is a mouse model for human systemic sclerosis.

METHODS

Newly born TSK/+ mice were treated with murine anti-CD40L monoclonal antibody (100 microg intraperitoneally weekly). Hypodermal thickness of 8-week-old female mice (defined as the thickness of a subcutaneous loose connective tissue layer beneath the panniculus carnosus) was measured under a light microscope. All skin sections were taken from the para-midline, upper back region. Serum anti-topoisomerase I autoantibody levels, serum immunoglobulin levels and plasma soluble CD40L levels were determined by enzyme-linked immunosorbent assay. For analysis of lymphocyte surface molecules, single cell suspensions of lymphocytes were stained by monoclonal antibodies. Proliferation of TSK/+ B cells and fibroblasts to anti-CD40 antibodies was assessed by the uptake of [3H]-labelled thymidine and bromodeoxyuridine, respectively.

RESULTS

The blockade of CD40/CD40L interactions by anti-CD40L monoclonal antibody significantly reduced cutaneous fibrosis (65%) and anti-topoisomerase I autoantibody in TSK/+ mice. Anti-CD40L monoclonal antibody also normalised B lymphocyte abnormal activation in TSK/+ mice, demonstrated by hyper-gamma-globulinaemia. Furthermore, augmented CD40/CD40L interactions in TSK/+ mice were suggested by upregulated expression of CD40L on CD4(+) T cells, elevated plasma soluble CD40L levels. The hyperresponsiveness to CD40 stimulation was also observed in TSK/+ B cells and fibroblasts.

CONCLUSIONS

Cutaneous fibrosis and autoimmunity in TSK/+ mice are closely correlated with CD40/CD40L interactions.

Involvement of the protein kinase Cγ isoform in development of tolerance to nitrous oxide–induced antinociception in mice

Prolonged exposure to nitrous oxide (N2O) results in development of acute tolerance to its antinociceptive effect. Cross-tolerance to N2O-induced antinociception is also observed in morphine-tolerant animals. Despite increasing evidence of tolerance development to N2O-induced antinociception, the details of the mechanisms that underlie this tolerance remain unknown. The present study was conducted to investigate the involvement of brain protein kinase C (PKC) isoform in these two types of tolerance to N2O-induced antinociception in mice. Prolonged exposure (41 min in total, including 30 min pre-exposure and 11 min of antinociceptive testing) to 70% N2O produced a reduction in N2O-induced antinociception, indicating development of acute tolerance. The prolonged exposure to 70% N2O caused an activation of PKCgamma isoform in the brain, but not the PKCepsilon isoform. Pretreatment with a PKCgamma-antisense oligonucleotide but not the corresponding mismatch oligonucleotide (i.c.v.) prevented the development of acute tolerance to N2O-induced antinociception. Chronic morphine treatment (10 mg/kg, s.c., b.i.d. for 5 days) resulted in development of tolerance to morphine-induced antinociception and cross-tolerance to N2O-induced antinociception. The development of tolerance to morphine and cross-tolerance to N2O were both inhibited by pretreatment with PKC inhibitor, chelerythrine (1 nmol, i.c.v.). Morphine-tolerant mice showed an activation of PKC within the brain, which was suppressed by pretreatment with chelerythrine (1 nmol, i.c.v.). Thus, activation of brain PKC, in particular, the PKCgamma isoform, appears to play an important role in the development of both acute tolerance and cross-tolerance to N2O-induced antinociception in mice.

Prediction of pharmacokinetics of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, in humans using animal data

The pharmacokinetics of CS-023 (RO4908463, formerly R-115685), a novel parenteral carbapenem antibiotic, in humans was successfully predicted using the data collected from mice, rats, rabbits, and dogs; while inclusion of the monkey data led to a significant underestimation of the total plasma clearance (CL). Double logarithmic plots of CL and distribution volume at the steady-state (Vss) vs. body weight in four animal species were linear with high correlation coefficients; and the predicted CL and Vss values in humans agreed well with the observed values after administration of CS-023 by an intravenous drip infusion for 30 min. The plasma concentration-time profile in humans, which was predicted using a bi-exponential equation fitted to a complex Dedrick plot of the animal data, approximated the observed profile. An underestimation of CL caused by including the monkey data in a prediction is quite likely due to the net tubular reabsorption in monkeys, but not at least in rabbits, dogs, and humans.

Renal handling of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, in rabbits in comparison with meropenem

The plasma half-life of CS-023 (RO4908463), a novel parenteral carbapenem antibiotic, is longer than that of meropenem in animals and humans. To address this issue, renal clearance studies were conducted in rabbits. A constant rate infusion of CS-023 and meropenem was conducted in male Japanese White rabbits. Concentrations in the plasma, urine and renal cortex were measured to evaluate renal clearance and renal tissue uptake. CS-023 showed a clearance ratio (renal clearance/glomerular filtration rate) of around 1, which was not affected by co-administration of probenecid or p-aminohippurate. On the other hand, meropenem exhibited a clearance ratio of around 3, which was significantly decreased to 1 by co-administration of probenecid. p-Aminohippurate, in contrast, had no effect. The renal cortex/plasma concentration ratio of CS-023 was around 0.6 with or without probenecid co-administration. This ratio of meropenem was around 3, which was decreased significantly by co-administration of probenecid to around 0.6. These data suggest that meropenem is secreted in the renal tubules via organic anion transporters, but CS-023 is not. The present findings in rabbits would indicate that a lack of renal tubular secretion of CS-023 is a reason for the long plasma half-life compared with meropenem.

Chain elongation suppression of cyclic block copolymers in lamellar microphase-separated bulk

Chain elongation suppression of cyclic block copolymers in microphase-separated bulk was determined quantitatively. Solvent-cast and annealed films are confirmed to show alternating lamellar structure and their microdomain spacing D increases with increasing total molecular weight M according to the relationship D proportional, variant M0.59, which agrees quite consistently with the theoretically predicted power law, i.e., D proportional, variant M3/5. This result is in contrast to the well-established issue for linear block copolymers, where the relationship D proportional, variant M2/3 has been confirmed to hold both experimentally and theoretically. This means that chain elongation of each component block is suppressed considerably, owing to their looped conformation in strongly segregated bulk.

Involvement of brain protein kinase C in nitrous oxide-induced antinociception in mice

Exposure of mice to the anesthetic gas nitrous oxide (N(2)O) produces a marked antinociceptive effect. Protein kinase C is a key regulatory enzyme that may be targeted by general anesthetics. However, a relationship between N(2)O-induced antinociception and protein kinase C has yet to be established. The present study was conducted to identify whether protein kinase C might influence N(2)O-induced antinociception in mice. Regular exposure (11 min) to N(2)O produced concentration-dependent antinociception in mice, as determined using the abdominal constriction test. N(2)O-induced antinociception was attenuated by i.c.v. pretreatment with phorbol 12,13-dibutyrate, a protein kinase C activator. This phorbol 12,13-dibutyrate antagonism of N(2)O-induced antinociception was reversed by i.c.v. pretreatment with calphostin C, a protein kinase C inhibitor. Long-term exposure (41 min in total, including 30 min prior to, and 11 min of analgesic testing) to 70% N(2)O produced reduced analgesic effects, compared with regular exposure to 70% N(2)O, thus indicating acute tolerance to N(2)O-induced antinociception. However, mice pretreated with calphostin C, chelerythrine, which is another protein kinase C inhibitor, and phorbol 12,13-dibutyrate, did not develop acute tolerance. Regarding activation of protein kinase C, regular exposure to 70% N(2)O did not increase protein kinase C within the membrane fraction of brain tissue, as determined by immunoblot analysis, but long-term exposure to 70% N(2)O did. The i.c.v. pretreatment with calphostin C and phorbol 12,13-dibutyrate prevented the increase in protein kinase C observed with long-term exposure to 70% N(2)O. These results suggest that brain protein kinase C negatively regulates the antinociceptive effect of N(2)O, and that activation of brain protein kinase C is related to the development of acute tolerance to N(2)O-induced antinociception in mice.