Prognosis and incidence of immunological and oncological complications after direct-acting antiviral therapy for chronic hepatitis C.

Background and study aims: The long-term comprehensive prognosis of chronic hepatitis C after direct-acting antiviral (DAA) therapy is unclear. This study aimed to investigate the prognosis and incidence of immunological and oncological complications after DAA therapy. Patients and methods: The study included a total of 1461 patients who received DAA therapy in our university hospital and affiliated hospitals between September 3, 2014 and September 30, 2018. Results: The incidence rates of total malignancies in overall or female patients after DAA therapy were significantly greater than expected in the corresponding general population. The same was true for lung malignancies. Predictive risk factors associated with the occurrence and recurrence of hepatic malignancies after DAA therapy in patients with sustained virological response were cirrhosis and insulin use, protein induced by vitamin K absence or antagonist-II level, and albumin-bilirubin score, respectively. Eight (0.5%) patients were diagnosed with autoimmune diseases after starting DAA therapy. Importantly, the attending physician considered a possible causal relationship between DAA therapy and these autoimmune diseases in five cases (four rheumatoid arthritis and one membranoproliferative glomerulonephritis). The 5-year overall survival rate was 91.6%. The most frequent primary cause of death was malignancy in 41 (60.2%) patients, including 25 with hepatic malignancies. Lung and colorectal cancers were the next most common. Conclusions: Given that the incidence of total and lung cancers might increase and DAA-related autoimmune diseases might emerge after DAA therapy, we should be alert for the development of these diseases as well as hepatic malignancies.

Hyperglycaemia augments lipopolysaccharide-induced reduction in rat and human macrophage phagocytosis via the endoplasmic stress-C/EBP homologous protein pathway.

BACKGROUND: Macrophage phagocytosis constitutes an essential part of the host defence against microbes and the resolution of inflammation. Hyperglycaemia during sepsis is reported to reduce macrophage function, and thus, potentiate inflammatory deterioration. We investigated whether high-glucose concentrations augment lipopolysaccharide-induced reduction in macrophage phagocytosis via the endoplasmic stress-C/EBP homologous protein (CHOP) pathway using animal and laboratory investigations. METHODS: Peritoneal macrophages of artificially ventilated male Wistar rats, divided into four groups based on target blood glucose concentrations achieved by glucose administration with or without lipopolysaccharide, were obtained after 24 h. Human macrophages were also cultured in normal or high glucose with or without lipopolysaccharide exposure for 72 h. Changes in the phagocytic activity, intranuclear CHOP expression, and intracellular Akt phosphorylation status of macrophages were evaluated. These changes were also evaluated in human macrophages after genetic knock-down of CHOP by specific siRNA transfection or resolvin D2 treatment. RESULTS: Lipopolysaccharide impaired phagocytosis, increased intranuclear expression of CHOP, and inhibited Akt phosphorylation in both rat peritoneal and human macrophages. Hyperglycaemic glucose concentrations augmented these changes. Genetic knock-down of CHOP restored phagocytic ability and Akt phosphorylation in human macrophages. Furthermore, resolvin D2 co-incubation restored the inhibited phagocytosis and Akt phosphorylation along with the inhibition of intranuclear CHOP expression in human macrophages. CONCLUSIONS: These findings imply that controlling endoplasmic reticulum stress might provide new strategies for restoring reduced macrophage phagocytosis in sepsis-induced hyperglycaemia.

Warm-, hot- and pain-related neural activities depending on baseline skin temperatures.

BACKGROUND: This study investigated the characteristics of temperature-related evoked neural activities to baseline skin temperatures on target and adjacent sites using contact heat evoked potentials (CHEPs). METHODS: Contact heat evoked potentials were recorded from 12 normal subjects during three stimuli: target temperatures for "warm", "hot" and "pain" were set at 41, 46 and 51 °C, respectively. The baseline temperature was separately set at 30, 35 and 40 °C under all conditions, and a heat pulse was delivered over the right forearm at 41 °C under the warm condition, at 46 °C under the hot condition and at 51 °C under the pain condition. RESULTS: The N2-P2 amplitude was significantly larger at the 40 °C baseline than at the 30 and 35 °C baselines during the pain condition, whereas no significant differences were observed during the hot and warm conditions. In addition, the effects of an interference warm stimulation to adjacent sites were examined; however, no significant effects were observed. CONCLUSIONS: These results suggest that the priming effects of temperature on CHEPs were only observed under the pain condition, indicating the specificity of thermal pain, as well as a difference in the neural mechanisms responsible for thermal noxious and innocuous processing in human brains. SIGNIFICANCE: This study using CHEPs shows the importance of baseline and target skin temperatures to investigate the characteristics of temperature-related neural activities. This measure may contribute to understanding of warm-, hot-, and pain-related neural activities in human brains.

Premenstrual enhancement of snake detection in visual search in healthy women.

It is well known that adult humans detect images of snakes as targets more quickly than images of flowers as targets whether the images are in color or gray-scale. When such visual searches were performed by a total of 60 adult premenopausal healthy women in the present study to examine whether their performance would fluctuate across the phases of the menstrual cycle, snake detection was found to become temporarily enhanced during the luteal phase as compared to early or late follicular phases. This is the first demonstration of the existence of within-individual variation of the activity of the fear module, as a predictable change in cognitive strength, which appears likely to be due to the hormonal changes that occur in the menstrual cycle of healthy women.

Gabapentin blocks methamphetamine-induced sensitization and conditioned place preference via inhibition of α2/δ-1 subunits of the voltage-gated calcium channels.

Our previous investigation demonstrated that repeated administration of morphine significantly enhanced α(2)/δ-1 subunit expression in the frontal cortex and limbic forebrain of mice as well as morphine-induced place preference. However, little is known about regulatory mechanisms of α(2)/δ-1 subunit expression in conditioned place preference by methamphetamine (METH). In the present study, we investigated the role of α(2)/δ-1 subunit of voltage-gated calcium channels (VGCCs) in the mouse brain under repeated treatment with METH. The level of α(2)/δ-1 subunit increased significantly in the limbic forebrain including the nucleus accumbens and the frontal cortex of mice showing METH-induced sensitization. Under these conditions, the development of behavioral sensitization induced by the intermittent administration of METH was significantly suppressed by the co-administration of gabapentin (GBP) with binding activity to an exofacial epitope of α(2)/δ-1 subunit. Furthermore, GBP administered i.c.v. caused a dose-dependent inhibition of the METH-induced place preference. Chronic GBP treatment at the dose alleviating sensitization and place preference significantly reduced the elevation of α(2)/δ-1 subunit of VGCC induced by the repeated administration of METH in the limbic forebrain and frontal cortex, whereas there were no changes in the increase of α(2)/δ-1 subunit mRNA. These findings indicate that α(2)/δ-1 subunit plays a critical role in the development of METH-induced place preference following neuronal plasticity, and that GBP, which significantly suppressed METH-induced place preference by its possible inhibitory action of α(2)/δ subunit to neuronal membrane, may possibly be used as an alternative drug to treat or prevent drug dependence.

The role of small molecule GPR119 agonist, AS1535907, in glucose-stimulated insulin secretion and pancreatic ß-cell function.

AIM: AS1535907, a small molecule agonist of GPR119, was assessed for its glucose-stimulated insulin secretory activity and pancreatic ß-cell function in type 2 diabetes. METHODS: Both in vitro and in vivo tests were conducted using NIT-1 and HEK293 cell lines, male normal and db/db mice and isolated perfused rat pancreas preparations. RESULTS: AS1535907 had an EC50 value of 1.5 µM for human GPR119 transfected in HEK293 cells. AS1535907 enhanced insulin secretion in NIT-1 cells and in the perfused rat pancreas. A transient increase in the human insulin promoter activity was also observed in NIT-1 cells. First-phase insulin secretion was particularly more evident in the AS1535907-treated perfused rat pancreas than that in the nateglinide or glibenclamide-treated group. Oral glucose tolerance improved following a single dose of AS1535907 in normal and db/db mice. Subsequently, 2 weeks of multiple dosing significantly increased plasma insulin levels and decreased blood glucose levels in db/db mice. After 3 weeks of treatment in db/db mice, the numbers of insulin and proliferation cell nuclear antigen-positive cells and the islet area were significantly higher than those in the vehicle-treated mice. As compared with the vehicle, gene expression analysis revealed that AS1535907 significantly upregulated transcription factors (Nkx 2.2, Nkx 6.1, NeuroD and activin A), responsible for ß-cell regulation and prohormone-converting enzyme 1 responsible for insulin biosynthesis. CONCLUSION: These results suggest that AS1535907 can potentially regulate first-phase insulin secretion and exert a protective effect on pancreatic ß-cell function via regulation of transcription factors.

Insufficient cutaneous vasoconstriction leading up to and during syncopal symptoms in the heat stressed human.

As much as 50% of cardiac output can be distributed to the skin in the hyperthermic human, and therefore the control of cutaneous vascular conductance (CVC) becomes critical for the maintenance of blood pressure. Little is known regarding the magnitude of cutaneous vasoconstriction in profoundly hypotensive individuals while heat stressed. This project investigated the hypothesis that leading up to and during syncopal symptoms associated with combined heat and orthostatic stress, reductions in CVC are inadequate to prevent syncope. Using a retrospective study design, we evaluated data from subjects who experienced syncopal symptoms during lower body negative pressure (N = 41) and head-up tilt (N = 5). Subjects were instrumented for measures of internal temperature, forearm skin blood flow, arterial pressure, and heart rate. CVC was calculated as skin blood flow/mean arterial pressure × 100. Data were obtained while subjects were normothermic, immediately before an orthostatic challenge while heat stressed, and at 5-s averages for the 2 min preceding the cessation of the orthostatic challenge due to syncopal symptoms. Whole body heat stress increased internal temperature (1.25 ± 0.3°C; P < 0.001) and CVC (29 ± 20 to 160 ± 58 CVC units; P < 0.001) without altering mean arterial pressure (83 ± 7 to 82 ± 6 mmHg). Mean arterial pressure was reduced to 57 ± 9 mmHg (P < 0.001) immediately before the termination of the orthostatic challenge. At test termination, CVC decreased to 138 ± 61 CVC units (P < 0.001) relative to before the orthostatic challenge but remained approximately fourfold greater than when subjects were normothermic. This negligible reduction in CVC during pronounced hypotension likely contributes to reduced orthostatic tolerance in heat-stressed humans. Given that lower body negative pressure and head-up tilt are models of acute hemorrhage, these findings have important implications with respect to mechanisms of compromised blood pressure control in the hemorrhagic individual who is also hyperthermic (e.g., military personnel, firefighters, etc.).

Early activation of the coagulation system during lower body negative pressure.

We considered that a moderate reduction of the central blood volume (CBV) may activate the coagulation system. Lower body negative pressure (LBNP) is a non-invasive means of reducing CBV and, thereby, simulates haemorrhage. We tested the hypothesis that coagulation markers would increase following moderate hypovolemia by exposing 10 healthy male volunteers to 10 min of 30 mmHg LBNP. Thoracic electrical impedance increased during LBNP (by 2.6 +/- 0.7 Omega, mean +/- SD; P < 0.001), signifying a reduced CBV. Heart rate was unchanged during LBNP, while mean arterial pressure decreased (84 +/- 5 to 80 +/- 6 mmHg; P < 0.001) along with stroke volume (114 +/- 22 to 96 +/- 19 ml min(-1); P < 0.001) and cardiac output (6.4 +/- 2.0 to 5.5 +/- 1.7 l min(-1); P < 0.01). Plasma thrombin-antithrombin III complexes increased (TAT, 5 +/- 6 to 19 +/- 20 microg l(-1); P < 0.05), indicating that LBNP activated the thrombin generating part of the coagulation system, while plasma D-dimer was unchanged, signifying that the increased thrombin generation did not cause further intravascular clot formation. The plasma pancreatic polypeptide level decreased (13 +/- 11 to 6 +/- 8 pmol l(-1); P < 0.05), reflecting reduced vagal activity. In conclusion, thrombin generation was activated by a modest decrease in CBV by LBNP in healthy humans independent of the vagal activity.

Associations between decay-accelerating factor polymorphisms and allergic respiratory diseases.

BACKGROUND: Allergic diseases such as asthma and allergic rhinitis are major causes of morbidity in developed countries. The pathology underlying allergic respiratory diseases is considered to be IgE-mediated type I allergy characterized by mucosal inflammation that occurs in response to allergen exposure. They are common diseases involving a complex inheritance. Complement systems are known to play an important role in allergic diseases. Decay-accelerating factor (DAF) is important for the regulation of the complement system and is a good candidate for determining the susceptibility to allergic diseases. OBJECTIVE: The present study aimed to investigate whether polymorphisms in the DAF gene are associated with allergic respiratory diseases in the Japanese population. METHODS: We performed mutation screenings of DAF and conducted a tag single-nucleotide polymorphisms (SNP) association analysis for 684 unrelated adult individuals with seasonal allergic rhinitis (SAR) with Japanese ceder pollen, 188 mite-sensitive adults with asthma, and 346 unrelated non-allergic healthy controls. RESULTS: DAF is located in the tight linkage disequilibrium (LD) block spanning 62 kb. The tag SNP analysis revealed that rs10746463 was significantly associated with SAR (P=0.00033) and mite-sensitive adult asthma (P=0.044). The rs2564978 and rs3841376 haplotypes, which are located in the promoter region of DAF, were in complete LD with rs10746463 (r2=1). Luciferase reporter assays with constructs containing the 5' flanking regions of DAF showed that the plasmid with rs2564978 C/rs3841376 deletion (the risk haplotype) had a statistically significantly lower transcriptional activity than that containing the rs2564978 T/rs3841376 insertion. CONCLUSIONS: Our results suggest that DAF is one of the genes involved in conferring susceptibility to allergic respiratory diseases and show that decreased levels of DAF may be associated with the enhanced specific IgE responses occurring in allergic diseases in the Japanese population.

Role of alpha2/delta subunit in the development of morphine-induced rewarding effect and behavioral sensitization.

Previous data demonstrate that L-type voltage-gated calcium channel (VGCC) blockers, which bind to alpha(1) subunits of VGCC to suppress Ca(2+) entry into cells, inhibit the development of psychological dependence on drugs of abuse, suggesting the upregulation of L-type VGCC in the development of psychological dependence. However, there are few available data on changes of the auxiliary subunit alpha(2)/delta modifying L-type VGCC under such conditions. We therefore investigated here the role of alpha(2)/delta subunits of VGCCs in the brain of mouse after repeated treatment with morphine. The treatment with morphine increased alpha(2)/delta subunit expression in the frontal cortex and the limbic forebrain of mice showing rewarding effect and sensitization to hyperlocomotion by morphine. The morphine-induced behavioral sensitization and place preference were also suppressed by gabapentin, which binds to an exofacial epitope of the alpha(2)/delta auxiliary subunits of VGCCs. These findings indicate that the upregulation of alpha(2)/delta subunit as well as alpha(1) subunits of VGCC in the frontal cortex and the limbic forebrain plays a critical role in development of morphine-induced rewarding effect and behavioral sensitization following neuronal plasticity.

Botulinum toxin abolishes sweating via impaired sweat gland responsiveness to exogenous acetylcholine.

BACKGROUND: Botulinum toxin A (BTX) disrupts neurotransmitter release from cholinergic nerves. The effective duration of impaired sweat secretion with BTX is longer relative to that of impaired muscle contraction, suggesting different mechanisms in these tissues. OBJECTIVES: The aim of this study was to test the hypothesis that BTX is capable of altering sweating by reducing the responsiveness of the sweat gland to acetylcholine. METHODS: BTX was injected into the dorsal forearm skin of healthy subjects at least 3 days before subsequent assessment. On the day of the experiment, intradermal microdialysis probes were placed within the BTX-treated area and in an adjacent untreated area. Incremental doses of acetylcholine were administered through the microdialysis membranes while the sweat rate (protocol 1; n = 8) or a combination of sweat rate and skin blood flow (protocol 2; n = 8) were assessed. RESULTS: A relative absence of sweating was observed at the BTX site for both protocols (protocol 1: 0.05 +/- 0.09 mg cm(-2) min(-1); protocol 2: 0.03 +/- 0.04 mg cm(-2) min(-1), both at the highest dose of acetylcholine), while the sweat rate increased appropriately at the control sites (protocol 1: 0.90 +/- 0.46 mg cm(-2) min(-1); protocol 2: 1.07 +/- 0.67 mg cm(-2) min(-1)). Cutaneous vascular conductance increased to a similar level at both the BTX and control sites. CONCLUSIONS: These results demonstrate that BTX is capable of inhibiting sweat secretion by reducing the responsiveness of the sweat gland to acetylcholine, while not altering acetylcholine-mediated cutaneous vasodilatation.

Expression profiling of genes related to asthma exacerbations.

BACKGROUND: Asthma is a chronic airway inflammatory disease; however, the molecular mechanisms that underlie asthma exacerbation are only partially understood. OBJECTIVE: To identify gene expression signatures that reflect the acute exacerbation of asthma, we examined the differential expression of genes during asthma exacerbation and stable condition by using microarray analysis. METHODS: The subjects were mite-sensitive asthmatic children and non-asthmatic control children. The children were divided into four groups (AE: asthma exacerbation, n=12; SA: stable asthma, n=11; IC: infected control, n=6; and NC: non-infected control, n=5). Total RNA was extracted from peripheral blood mononuclear cells and subjected to microarray analysis with Illumina Human Ref8 BeadChip arrays. Welch's t-test was performed to identify genes whose expression was altered during asthma exacerbation. Quantitative real-time RT-PCR was performed on samples collected from 43 asthmatic children and 11 control children to verify the microarray results. RESULTS: The expression of 137/16 genes was significantly up/down-regulated during asthma exacerbation assessed by microarray analysis. Of the genes, 62 were also differentially expressed during upper respiratory infection. Many of the asthma exacerbation related genes were involved in defence responses and responses to external stimuli, but these associations disappeared after excluding the infection-related genes. Quantitative real-time RT-PCR confirmed that the genes related (S100A8 and GAS6) and unrelated to infections (CD200 and RBP7) were differentially expressed during asthma exacerbation (P<0.01). CONCLUSIONS: Previously unidentified immune responses during asthma exacerbation may provide further clarification of the molecular mechanisms underlying asthma.

Effects of antidiabetic drugs on glucose tolerance in streptozotocin-nicotinamide-induced mildly diabetic and streptozotocin-induced severely diabetic mice.

In this study, streptozotocin-nicotinamide-induced mildly diabetic mice and streptozotocin-induced severely diabetic mice were created to compare their characteristics and to investigate the effects of antidiabetic drugs on glucose tolerance. In severely diabetic mice, the pancreatic insulin content decreased to approximately 10% of levels found in normal mice. These mice also showed a decrease in body weight, a marked increase in nonfasting blood glucose levels and urinary glucose excretion, and a marked decline in glucose tolerance due to insulin secretory deficiency. In contrast, the pancreatic insulin content was approximately 50% of normal levels in mildly diabetic mice. These mice did not show any change in body weight, but displayed a mild increase in nonfasting blood glucose levels and urinary glucose excretion, and a mild decline in glucose tolerance due to loss of early-phase insulin secretion. Administration of antidiabetic drugs, namely voglibose, metformin, glibenclamide, sitagliptin and insulin, significantly improved glucose tolerance in mildly diabetic mice. In severely diabetic mice, voglibose, metformin and insulin significantly improved glucose tolerance, but no significant effect was observed for glibenclamide and sitagliptin due to a decreased insulinotropic effect. These results demonstrate that streptozotocin-nicotinamide-induced mildly diabetic mice have many pathological features resembling type 2 diabetes, and can serve as models for the pharmacological evaluation of many antidiabetic drugs.

Pharmacologic action of oseltamivir on the nervous system.

Oseltamivir, an antiviral drug used for the treatment of influenza, contains the L-glutamic acid motif in its chemical structure. We focused on this structural characteristic of oseltamivir and examined the pharmacologic effects of the drug on the nervous system in invertebrate and vertebrate animal models. Injection of oseltamivir or L-glutamic acid into silkworm (Bombyx mori) larvae induced muscle relaxation. Oseltamivir and L-glutamic acid inhibited kainate-induced rapid muscle contraction, but neither drug affected insect cytokine paralytic peptide-induced slow muscle contraction. In the mammalian system, mice (Mus musculus) treated intracerebrally with oseltamivir developed convulsive seizures. Hydrolyzed oseltamivir, the active form containing a carboxylic acid, evoked epileptiform firing of hippocampal neurons in rat (Rattus norvegicus) organotypic hippocampal slice cultures. These results are the first to demonstrate that oseltamivir exerts pharmacologic effects on the nervous system in insects and mammals.

Increased platelet, leukocyte, and endothelial cell activity are associated with increased coagulability in patients after total knee arthroplasty.

BACKGROUND: Orthopedic surgery, especially total knee and total hip arthroplasty, is considered a risk factor for peri-operative venous thromboembolism. OBJECTIVES: This study evaluates how accelerated inflammatogenic cellular interactions and the subsequent production of tissue factor and CD40 ligand play an important role in the pathogenesis of venous thromboembolism. PATIENTS AND METHODS: Twenty-four patients undergoing total knee arthroplasty were randomly assigned to groups with (Ti; n = 12) and without (Tn; n = 12) pneumatic tourniquet inflation. RESULTS: Numbers of leukocyte-platelet aggregates, especially those comprising monocytes-platelets in central venous blood from the Ti group, were increased during the peri-operative period (P < 0.01), and returned to the baseline level at 24 h after starting surgery. Levels of PAC-1, P-selectin, CD40 ligand, tissue factor, Mac-1 expression on monocytes including monocyte-platelet aggregates, and the number of microparticles including those of endothelial cell origin were noticeably increased in central venous blood from the Ti group (P < 0.01). Whole blood coagulability was also obviously increased in central venous blood from the Ti group (P < 0.01). Furthermore, the concentrations of venous plasma tissue factor antigen, CD40 ligand, platelet factor 4, beta-thromboglobulin, the soluble fibrin monomer complex and prothrombin fragment 1+2 were also increased (P < 0.05). CONCLUSIONS: This study showed that platelet, leukocyte and endothelium activities as well as their interactions are enhanced during the peri-operative period of total knee arthroplasty, particularly in venous blood from the lower half of the body, which consequently augments blood coagulability. Further, tourniquet inflation during surgery exaggerates these responses.

Catalytically inactive lipoprotein lipase overexpression increases insulin sensitivity in mice.

Abnormalities in lipoprotein lipase (LPL) function contribute to the development of hypertriglyceridemia, one of the characteristic disorders observed in the metabolic syndrome. In addition to the hydrolyzing activity of triglycerides, LPL modulates various cellular functions via its binding ability to the cell surface. Here we show the effects of catalytically inactive LPL overexpression on high-fat diet (HFD)-induced decreased systemic insulin sensitivity in mice. The binding capacity of catalytically inactive G188E-LPL to C2C12 skeletal muscle cells was not significantly different from that of wild type LPL. Insulin-stimulated IRS-1 phosphorylation and glucose uptake were increased by addition of wild type or mutant LPL in C2C12 cells. After 10 weeks' of HFD feeding, mice had significantly higher blood glucose levels than chow-fed mice in insulin tolerance tests. The blood glucose levels after insulin injection was significantly decreased in mutated LPL-overexpressing mice (G188E mice), as well as in wild type LPL-overexpressing mice (WT mice). Overexpression of catalytically inactive LPL, as well as wild type LPL, improved impaired insulin sensitivity in mice. These results show that decreased expression of LPL possibly causes the insulin resistance, in addition to hypertriglyceridemia, in metabolic syndrome.

ADAM33 polymorphisms are associated with asthma susceptibility in a Japanese population.

BACKGROUND: Asthma is the most common chronic disorder in childhood, and asthma exacerbation is an important cause of childhood morbidity and hospitalization. Asthma is believed to be a complex disorder involving genetic and environmental factors, and several asthma susceptibility loci have been identified through genome-wide screening. A disintegrin and metalloprotease 33 (ADAM33) was the first asthma susceptibility gene to be discovered by positional cloning in 2002. OBJECTIVE: The aim of the present study was to investigate whether single-nucleotide polymorphisms (SNPs) in ADAM33 are associated with childhood asthma in the Japanese population. METHODS: Twenty-three ADAM33 SNPs were genotyped by fluorescence correlation spectroscopy with the use of DNA from 155 families (538 members) identified through children with atopic asthma. The transmission disequilibrium test (TDT) was performed for family-based association study. RESULTS: TDT revealed that minor alleles of S+1, ST+4, and T2 SNPs were over-transmitted to asthma-affected offspring (P<0.05). According to the haplotype TDT, no haplotype of ADAM33 was transmitted preferentially to asthmatic offspring. CONCLUSION: Our results confirm the involvement of ADAM33 in the development of childhood asthma among the Japanese.

Haplotype analysis of a 100 kb region spanning TNF-LTA identifies a polymorphism in the LTA promoter region that is associated with atopic asthma susceptibility in Japan.

BACKGROUND: The tumour necrosis factor (TNF) gene family, which includes TNF, LTA, and LTB, is located consecutively on human chromosome 6p21 region, which has been linked to asthma by several genome-wide screens. (LTA, lymphotoxin-alpha; LTB, lymphotoxin-beta). OBJECTIVE: The aim of the present study was to determine whether genes on 6q21 are related to development of atopic asthma. Methods We screened for mutations in the coding and promoter regions of genes in the TNF-LTA region, including BAT1, NFKBIL1, LTA, TNF, LTB, AIF, and BAT2, and conducted a transmission disequilibrium test of 41 polymorphisms in 137 families identified through pro-bands with childhood-onset atopic asthma. (BAT1, HLA-B-associated transcript 1; NFKBIL1, nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor-like 1; AIF, allograft inflammatory factor 1). RESULTS: Haplotypes of the LTA/TNF linkage disequilibrium block were associated significantly with asthma (global P=0.0097). Transmission patterns of the common haplotypes to asthmatic offspring were predicted by a single-nucleotide polymorphism in the LTA promoter region. The G allele of the LTA-753G/A polymorphism was transmitted preferentially to asthma-affected individuals (P=0.001). Luciferase reporter assays with constructs containing the 5' and 3' flanking regions of the LTA gene showed 30-50% lower transcriptional activity when the -753A allele was present than that of other haplotypes. CONCLUSION: Our results suggest that LTA is one of the genes that contributes to susceptibility to atopic asthma, and that the association of the TNF/LTA haplotypes to asthma may be defined by the polymorphism in the LTA promoter region in the Japanese population.

Impaired glucose tolerance is accompanied by decreased insulin sensitivity in tissues of mice implanted with cells that overexpress resistin.

AIM/HYPOTHESIS: Resistin, the expression of which is suppressed by thiazolidinedione treatment in adipocytes, is one of the key molecules for the tight link between adiposity and insulin resistance. Here, we show the in vivo effects of resistin on insulin sensitivity in mature mice using a cell implantation method. METHODS: Resistin cDNA was transfected into 3T3-L1 pre-adipocytes, which were then implanted into subcutaneous areas of nude mice. Metabolic analyses were performed 4 or 6 weeks after implantation. RESULTS: The mice implanted with 3T3-L1 cells overexpressing resistin (R-mice) showed significantly (p<0.05) increased plasma resistin levels. After a glucose load plasma insulin levels were significantly greater in R-mice than in mice implanted with mock-transfected cells (M-mice). The AUC of insulin after glucose loading was positively correlated with circulating resistin levels. Significantly decreased glucose responses after insulin injection were observed in R-mice, compared to M-mice. The insulin-induced phosphorylation level of IRS-1 was significantly lower in muscles of R-mice than M-mice. The expression of TNF-alpha mRNA in intra-peritoneal fat tissues was significantly greater in R-mice than in M-mice, but there was no difference between the two groups with regard to subcutaneous fat tissues. The concentration of TNF-alpha in plasma was positively correlated with resistin levels in R-mice. CONCLUSIONS/INTERPRETATION: Resistin, when actually secreted from cells in mature mice, causes disturbed glucose metabolism, possibly based on decreased insulin sensitivity in muscle. The in vivo effects of resistin on insulin sensitivity might be in part mediated by increased TNF-alpha expression in visceral fat tissues.