The regulatory G protein signaling complex, Gß5-R7, promotes glucose- and extracellular signal-stimulated insulin secretion.

G protein-coupled receptors (GPCRs) are important modulators of glucose-stimulated insulin secretion, essential for maintaining energy homeostasis. Here we investigated the role of Gß5-R7, a protein complex consisting of the atypical G protein ß subunit Gß5 and a regulator of G protein signaling of the R7 family. Using the mouse insulinoma MIN6 cell line and pancreatic islets, we investigated the effects of G protein subunit ß 5 (Gnb5) knockout on insulin secretion. Consistent with previous work, Gnb5 knockout diminished insulin secretion evoked by the muscarinic cholinergic agonist Oxo-M. We found that the Gnb5 knockout also attenuated the activity of other GPCR agonists, including ADP, arginine vasopressin, glucagon-like peptide 1, and forskolin, and, surprisingly, the response to high glucose. Experiments with MIN6 cells cultured at different densities provided evidence that Gnb5 knockout eliminated the stimulatory effect of cell adhesion on Oxo-M-stimulated glucose-stimulated insulin secretion; this effect likely involved the adhesion GPCR GPR56. Gnb5 knockout did not influence cortical actin depolymerization but affected protein kinase C activity and the 14-3-3ϵ substrate. Importantly, Gnb5-/- islets or MIN6 cells had normal total insulin content and released normal insulin amounts in response to K+-evoked membrane depolarization. These results indicate that Gß5-R7 plays a role in the insulin secretory pathway downstream of signaling via all GPCRs and glucose. We propose that the Gß5-R7 complex regulates a phosphorylation event participating in the vesicular trafficking pathway downstream of G protein signaling and actin depolymerization but upstream of insulin granule release.

Resting-state global functional connectivity as a biomarker of cognitive reserve in mild cognitive impairment.

Cognitive reserve (CR) shows protective effects in Alzheimer's disease (AD) and reduces the risk of dementia. Despite the clinical significance of CR, a clinically useful diagnostic biomarker of brain changes underlying CR in AD is not available yet. Our aim was to develop a fully-automated approach applied to fMRI to produce a biomarker associated with CR in subjects at increased risk of AD. We computed resting-state global functional connectivity (GFC), i.e. the average connectivity strength, for each voxel within the cognitive control network, which may sustain CR due to its central role in higher cognitive function. In a training sample including 43 mild cognitive impairment (MCI) subjects and 24 healthy controls (HC), we found that MCI subjects with high CR (> median of years of education, CR+) showed increased frequency of high GFC values compared to MCI-CR- and HC. A summary index capturing such a surplus frequency of high GFC was computed (called GFC reserve (GFC-R) index). GFC-R discriminated MCI-CR+ vs. MCI-CR-, with the area under the ROC = 0.84. Cross-validation in an independently recruited test sample of 23 MCI subjects showed that higher levels of the GFC-R index predicted higher years of education and an alternative questionnaire-based proxy of CR, controlled for memory performance, gray matter of the cognitive control network, white matter hyperintensities, age, and gender. In conclusion, the GFC-R index that captures GFC changes within the cognitive control network provides a biomarker candidate of functional brain changes of CR in patients at increased risk of AD.

Association of maternal anti-HLA class II antibodies with protection from allergy in offspring.

BACKGROUND: Recent studies have suggested that the birth order effect in allergy may be established during the prenatal period and that the protective effect may originate in the mother. HLA class II disparity between mother and foetus has been associated with significantly increased Th1 production. In this study, we investigated whether production of HLA antibodies 4 years after pregnancy with index child is associated with allergic outcomes in offspring at 8 years. METHODS: Anti-HLA class I and II antibodies were measured in maternal serum (n = 284) and levels correlated to numbers of pregnancies and birth order, and allergic outcomes in offspring at 8 years of age. RESULTS: Maternal anti-HLA class I and II antibodies were significantly higher when birth order, and the number of pregnancies were larger. Anti-HLA class II, but not class I antibodies were associated with significantly less atopy and seasonal rhinitis in the offspring at age 8 years. Mothers with nonatopic (but not atopic) offspring had a significant increase in anti-HLA class I and II antibodies with birth order. CONCLUSION: This study suggests that the 'birth order' effect in children may be due to parity-related changes in the maternal immune response to foetal antigens. We have observed for the first time an association between maternal anti-HLA class II antibodies and protection from allergy in the offspring. Further work is required to determine immunologically how HLA disparity between mother and father can protect against allergy.

Model selection for modified gravity.

In this article, we review model selection predictions for modified gravity scenarios as an explanation for the observed acceleration of the expansion history of the Universe. We present analytical procedures for calculating expected Bayesian evidence values in two cases: (i) that modified gravity is a simple parametrized extension of general relativity (GR; two nested models), such that a Bayes' factor can be calculated, and (ii) that we have a class of non-nested models where a rank-ordering of evidence values is required. We show that, in the case of a minimal modified gravity parametrization, we can expect large area photometric and spectroscopic surveys, using three-dimensional cosmic shear and baryonic acoustic oscillations, to 'decisively' distinguish modified gravity models over GR (or vice versa), with odds of ≫1:100. It is apparent that the potential discovery space for modified gravity models is large, even in a simple extension to gravity models, where Newton's constant G is allowed to vary as a function of time and length scale. On the time and length scales where dark energy dominates, it is only through large-scale cosmological experiments that we can hope to understand the nature of gravity.

Heightening of the stress response during the first weeks after a mild traumatic brain injury.

The effects of a mild traumatic brain injury range from white matter disruption to affective disorders. We set out to determine the response to restraint-induced stress after a mild fluid-percussion injury (FPI), an experimental model for brain injury. Hypothalamic-pituitary-adrenal (HPA) axis regulation of corticosterone (CORT) and adrenocorticotropic hormone (ACTH) was determined during the first post-injury weeks, which corresponds to the same time period when rehabilitative exercise has been shown to be ineffective after a mild FPI. Adult male rats underwent either an FPI or sham injury. Additional rats were only exposed to anesthesia. HPA regulation was evaluated by measuring the effects of dexamethasone (DEX) treatment on CORT and ACTH. Tail vein blood was collected following 30-min restraint stress, at post-injury days (PID) 1, 7 and 14, prior to (0 min) and at 30, 60, 90 and 120 min after stress onset. Results from these studies indicate that the stress response was significantly more pronounced after FPI in that CORT and ACTH restraint-induced increases were more pronounced and longer lasting compared to controls. DEX suppression of CORT and ACTH was observed in all groups, suggesting that stress hyper-responsiveness after mild FPI is not attributable to reduced sensitivity of CORT feedback regulation. The increased sensitivity to stressful events in the first two post-injury weeks after a mild FPI may have a negative impact on early rehabilitative therapies.

Parity violation constraints using cosmic microwave background polarization spectra from 2006 and 2007 observations by the QUaD polarimeter.

We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 degrees +/-0.82 degrees (random) +/-0.5 degrees (systematic) using QUaD's 100 and 150 GHz temperature-curl and gradient-curl spectra over the spectra over the multipole range 200

Isolation and characterization of 12 dinucleotide microsatellite loci in the anadromous fish Osmerus eperlanus (L.).

A subtractive hybridization method was used to isolate 12 dinucleotide microsatellite loci for the anadromous European smelt, Osmerus eperlanus (L.). Three to 17 (mean 8.08) alleles per locus were identified in the two populations screened, and observed heterozygosity ranged from 0.067 to 0.933. Loci in both populations showed significant deviations from Hardy-Weinberg expected frequencies. These 12 loci provide a good basis for investigation of O. eperlanus population structure.

Association of HLA-DQ5 and HLA-DR1 with sensitization to organic acid anhydrides.

BACKGROUND: Organic acid anhydrides are low molecular weight industrial chemicals, able to cause rhinoconjunctivitis and asthma associated with specific IgE against hapten-carrier protein conjugate. Only a proportion of exposed workers develop IgE-associated allergy to acid anhydrides. OBJECTIVE: We determined whether genetic susceptibility, in particular, HLA Class II alleles may be a risk factor. METHODS: We undertook HLA typing in 52 cases who had confirmed specific IgE and in 73 referents matched on site, age and duration of acid anhydride exposure identified in cross-sectional studies of workers exposed to hexahydrophthalic (HHPA), methylhexahydrophthalic (MHHPA) and methyltetrahydrophthalic (MTHPA) anhydrides. RESULTS: The linked alleles DQ5 (odds ratio [OR]=4.3; 95% confidence interval [95% CI]=1.7, 11) and DR1 (OR 3.0; 95% CI 1.2, 11) were more prevalent in cases than in referents. Within DQ5, DQB1(*)0501 was particularly frequent (OR 3.0; 95% CI 1.2, 7.4). CONCLUSION: DQB1(*)05 gene confers susceptibility to develop specific IgE antibodies against HHPA, MHHPA and a non-significant trend with MTHPA. DQB1(*)0501 is protective for other low molecular chemical sensitizers (isocyanates and plicatic acid) which may indicate varying affinities for the corresponding specific class II molecules.

Serum levels of sex hormones and corticosterone throughout 4- and 5-day estrous cycles in Fischer 344 rats and their simulation in ovariectomized females.

Among inbred strains of rats, the Fischer 344 (F344) is commonly used in immunological and behavioral studies. However, little is known about patterns of sex hormones and corticosterone (CORT) secretion throughout the estrous cycle in this strain, which is characterized by a marked CORT response to stress and variable length of cycles. In the current study, using radioimmunoassays, we assessed serum levels of progesterone, estradiol, LH, testosterone, prolactin and CORT, at 1-h intervals throughout the estrous cycle in F344 female rats with 4- and 5-day cycles, as well as in males. Vaginal smears were obtained from 268 females for 15 consecutive days to determine individual length of the estrous cycle and the exact estrous phase upon blood withdrawal, which was conducted once in each rat on the 12th day of smearing. The results indicated that both 4- and 5-day cyclers have two distinct and marked surges of progesterone, one on proestrus day and the other on diestrous-1 day. Testosterone levels in 5-day cyclers peaked on diestrus-3, one day earlier than in 4-day cyclers. Daily peak levels of CORT gradually increased from estrus day to proestrous day, whereas daily nadir levels of CORT remained unchanged. To simulate the natural kinetics of specific sex hormones in ovariectomized females, different doses of estradiol, progesterone, testosterone, prolactin or CORT were injected s.c. or i.p., or 90-day sustained release pellets containing different doses of estradiol or progesterone were implanted. The findings indicated dose- and time-dependent effects, suggesting regimens for modeling the estrous cycle or replacement therapy.

Intracerebroventricular interleukin-1beta impairs clearance of tumor cells from the lungs: role of brain prostaglandins.

We have previously demonstrated that central administration of interleukin (IL)-1beta suppresses natural killer (NK) cell activity, impairs NK-mediated lung clearance of tumor cells, and enhances tumor colonization. The central pathways activated by IL-1beta are as yet unknown. Using an in vivo model of tumor colonization, this study examined the role of central noradrenergic, opioid and prostaglandin mechanisms in mediating the effect of IL-1beta on lung clearance of tumor cells. We demonstrate that central noradrenergic and opioid systems are not critically involved in this effect. Neither depletion of central noradrenergic pathways, or administration of the opioid antagonist, naltrexone (50 ug), blocked the impaired lung clearance of MADB106 tumor cells induced by central administration of IL-1beta (20 ng). Central prostaglandins (PGs) do, however, appear to play a critical role. Central administration of the prostaglandin antagonist, diclofenac (250 ug), but not ibuprofen, completely blocked the effect of IL-1beta on lung clearance of tumor cells. Antagonism of the effects of IL-1beta was shown to be due to the effects of centrally and not of peripherally acting prostaglandins.

The glossopharyngeal nerve as a novel pathway in immune-to-brain communication: relevance to neuroimmune surveillance of the oral cavity.

Glossopharyngeal afferents may be the neural channel by which immune challenge of the posterior oral cavity conveys information to the brain. If this is the case, then bilateral transection of the glossopharyngeal nerves (GLOx) should disrupt this communication. Injection of lipopolysaccharide (LPS) or interleukin (IL)-1beta into the soft palate (ISP) of sham-operated rats induced a dose-related febrile response. GLOx significantly attenuated the febrile response induced by ISP injection of both LPS and IL-1beta. In contrast, GLOx did not affect the febrile response when LPS or IL-1beta were injected intraperitoneally, indicating that the effect of GLOx is not systemic. These results provide experimental evidence for a novel neural pathway for immune-to-brain communication.

Role of human leukocyte antigen phenotype and exposure in development of occupational asthma.

Studies of factory workforces in the past decade, exposed to both inhaled protein allergens (e.g. enzymes) and low molecular weight sensitisers (e.g. acid anhydrides), have provided consistent evidence of exposure-response relationships for both sensitisation (IgE production) and asthma. The development of molecular techniques has allowed investigation of candidate gene, in particular HLA Class 2 alleles, as risk factors contributing to individual susceptibility, in particular to low molecular weight chemicals. The frequency of HLA DR3 in cases of sensitisation to trimellitic anhydride and ammonium hexachloroplatinate is increased as compared to referents who have experienced a comparable intensity and duration of exposure. Similarly, HLA DQB1Asp57 is consistently more frequent in cases of isocyanate induced asthma. These observations indicate HLA Class 2 molecules contribute to individual susceptibility to sensitisation and asthma caused by low molecular weight chemicals. A study of platinum refinery workers suggested the relative risk associated with HLA phenotype was greater at lower levels of exposure.

Interstitial lung diseases: an epidemiological overview.

Epidemiological studies on interstitial lung diseases (ILDs) may be schematically subdivided into the following major types: 1) quantifications of disease, broken down into incidence, prevalence and mortality data; 2) identification of aetiological factors; and 3) clinical epidemiological studies. Epidemiological data may be obtained from different sources or population groups, using different study designs such as systematic national statistics, population-based data and registries, and large case series of specific diseases. Differences in results between epidemiological studies may be due to real differences in incidence, but may also be due to changes in disease definitions and classifications, differences in the epidemiological design of the studies, or even registration bias. Comparative epidemiological data of different ILDs are almost limited to the general population study in Bernalillo County and to national mortality statistics, which should be interpreted with great caution. Also, some, mostly national registries of the different ILDs have been carried out by specific medical profession groups (especially pulmonologists), which clearly underestimate the real incidence of ILDs, but in which the comparison of the relative frequencies is probably accurate. Based on all these comparative studies, sarcoidosis and idiopathic pulmonary fibrosis appear to be the most frequent ILDs, followed by hypersensitivity pneumonitis and ILD in collagen vascular disease, when classical pneumoconioses are not included. There is also a relatively large group of nonspecific fibrosis. Much more data have been published on the epidemiology of specific forms of interstitial lung disease. Most information is available on the epidemiology of sarcoidosis, and those data are probably the most accurate. Data on idiopathic pulmonary fibrosis have the disadvantage of the recent changes in definition and classification of this disease. Hypersensitivity pneumonitis has been studied epidemiologically, especially in some exposure groups such as farmers and pigeon breeders, and in some regions in North America, UK, France and Scandinavia. Estimates of frequencies of interstitial lung disease in collagen vascular disease or of drug-induced interstitial lung disease are less accurate and more variable, depending on diagnostic criteria. Notwithstanding the aforementioned problems, this report tries to provide a balanced overview of the epidemiology of different interstitial lung diseases.

Identification of four novel interleukin-13 gene polymorphisms.

The development of allergic asthma is thought to involve environmental and inherited genetic components and has pathophysiological features reflecting in part the activity of T cell cytokines. Interleukin-13, a product primarily of activated lymphocytes, is considered to be a critical effector molecule in allergic airway response and has been found to be overexpressed in the airways of patients with asthma. The IL-13 gene is located on chromosome 5q31, one of the major loci to be linked to asthma susceptibility, and amongst a cluster of genes which dominate the immunopathology of allergic disease. Recently, an IL-13 promoter polymorphism was found to be associated with allergic asthma. In the present study we report the identification of four novel biallelic polymorphisms in the IL-13 gene, two intronic and two exonic, one of which results in a basic to hydrophilic amino acid change. We characterised the frequencies of these four biallelic polymorphisms and the frequencies of the haplotypes, resulting from the combination of these four biallelic polymorphisms, in a population of 196 UK Caucasoid healthy individuals.

Lysosphingomyelin prevents behavioral aberrations and hippocampal neuron loss induced by the metabotropic glutamate receptor agonist quisqualate.

1. Excessive excitation of brain neurons by the excitatory neurotransmitter, glutamate, induces a cascade of events leading to increased intracellular Ca++, neuronal degeneration and death. 2. Recent in vitro research has demonstrated that a natural cationic amphiphile in the brain, lysosphingomyelin, may be able to prevent neuronal degeneration by repressing phosphosinositidase-C overactivation induced by excessive excitation of the metabotropic glutamate receptor. 3. This research tested the latter finding in vivo in a rat model of glutamate excitotoxicity. Intracerebroventricular (i.c.v.) administration of the Group 1 metabotropic glutamate receptor (mGluR) agonist, quisqualate, produced seizures, akinesia, destruction of hippocampal pyramidal cell dendritic microtubule-associated protein-2, and major loss of hippocampal CA sector neurons. 4. Prophylactic i.c.v. infusion of lysosphingomyelin powerfully attenuates these quisqualate-induced behaviors and prevents neuronal degeneration. 5. Lysosphingomyelin may be of clinical use in allaying progressive Group 1 mGluR-induced hippocampal cognitive and motor disorders including Alzheimer's disease, brain seizure, and stroke.

Fetal alcohol exposure attenuates interleukin-1beta-induced fever: neuroimmune mechanisms.

Central mechanisms for the attenuating effects of fetal alcohol exposure (FAE) on interleukin-1beta (IL-1beta)-induced fever were studied in adult male offspring of dams fed a liquid diet supplemented with ethanol (E), in pair-fed (P) control and in normal (N) offspring. Hypothalamic levels of IL-1 were significantly lower in E than in N rats at 2 h, but not at 4 and 6 h, after intraperitoneal administration of lipopolysaccharide. Fever induced by intracerebroventricular (i.c.v.) IL-1 was significantly lower in E than in N and P rats. In contrast, E rats showed a normal febrile response to i.c.v. prostaglandin-E2. Thus, whereas FAE does not affect central thermoregulatory mechanisms, per se, FAE alters the kinetics of hypothalamic IL-1 production/appearance and decreases the responsiveness of central mechanisms which mediate the febrile response to IL-1.

Thymocyte development in male fetal alcohol-exposed rats.

We previously reported altered responses of thymocytes to mitogen stimulation after fetal alcohol exposure (FAE) in prepubertal male Sprague-Dawley rats. The purpose of this study was to examine the effect of FAE on the developmental pattern of thymocyte subsets. In the first experiment, we found that the proportion of double-labeled CD4+CD8+ thymocytes is identical in fetal alcohol-exposed (E) and control (C) animals at 34 and 45 days of age. In the second experiment--at 20, 28, 35, and 48 days of age--we examined the proportion of CD4+ and CD8+ thymocytes that express or are devoid of the maturational markers, the alpha/beta configuration of the T-cell receptor (TcR), and the restriction fragment C of the common leukocyte antigen (CD45RC). We found significant age-dependent effects on the numbers of total double-positive CD4-TcR and CD8-TcR or CD45RC thymocytes, and significantly lower numbers of total CD4+ and CD8+ cells in E than in C rats throughout this period--a finding consistent with the significantly lower total number of thymocytes in E than in C rats. The developmental patterns for both markers were similar in E and C groups, in both the rising (days 20 to 28) and declining (days 35 to 48) phases. However, on day 35, E rats had significantly lower numbers of double-positive CD8-TcR and CD8-CD45RC cells than C rats. It therefore seems that FAE tends to accelerate the decline of double-positive CD8-TcR and CD8-CD45RC cells. The contribution of this phenotypic change to the thymic functional alterations induced by FAE remains to be determined.

Intracerebral interleukin-1beta impairs response to tumor invasion: involvement of adrenal catecholamines.

Interleukin-1beta (IL-1beta) is released within the brain following stress, trauma, infection, and in specific brain disorders. This centrally acting IL-1beta has recently been shown to impair peripheral immunity. Central administration of IL-1beta suppresses natural killer (NK) cell activity impairs lung clearance of tumor cells and enhances tumor colonization. Using an in vivo model of tumor colonization (lung clearance of NK-sensitive MADB106 adenocarcinoma cells), this study examined the role of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS) in mediating these effects. We demonstrate that adrenalectomy significantly attenuated the impaired lung clearance of MADB106 tumor cells induced by intracerebroventricular (i.c.v.) administration of IL-1beta (20 ng). Supplementing adrenalectomized animals with corticosterone did not reinstate the effect. The effect of IL-1beta on lung clearance was blocked by pretreatment with the beta-adrenergic antagonist, nadolol (0.5 mg/kg), but not by the alpha-antagonist phentolamine (5 mg/kg). Peripheral noradrenergic pathways are not implicated given that systemic administration of the noradrenergic neurotoxin, 6-hydroxydopamine, did not block the effect of IL-1beta. Taken together, these findings indicate that IL-1beta impairs lung clearance of MADB106 tumor cells via the actions of adrenal catecholamines, most likely epinephrine, acting at beta-adrenergic receptors in the periphery.

Immunologic cross-reactivity between respiratory chemical sensitizers: reactive dyes and cyanuric chloride.

BACKGROUND: CyCl is a low molecular weight reactive chemical used as an intermediate in the production of plastics, herbicides, pharmaceuticals, and fiber-reactive dyes. It is a potent inducer of specific IgE antibody. The CyCl functionality is a structural component of monochlorotriazine and dichlorotriazine dyes. OBJECTIVE: We have investigated the immunologic cross-reactivity between cyanuric chloride (CyCl) and reactive dyes and it was hypothesized that this moiety might be a dye epitope and that it might stimulate an allergic antibody response in dye-exposed workers. METHODS: To test this hypothesis, we have used sera with IgE antibodies to CyCl and also sera from dye-exposed workers who have IgE antibodies to Procion Orange MX2R, an azo dye containing the dichlorotriazine group. As a control group we have used dye-exposed workers with IgE antibody to Remazol Black B, a diazo dye containing the vinyl sulfone-reactive group. RESULTS: Using RAST and RAST inhibitions, we identified negligible cross-reactivity between CyCl and dichlorotriazine dye. CONCLUSION: The results of this study imply that the allergenic moiety on the dye residue resides in the chromophore rather than in the common structural component of CyCl and dichlorotriazine dyes.

Psychosine blocks quisqualate-induced glutamate excitotoxicity in hippocampal CA sector neurons.

Quisqualate is a potent specific agonist for Group 1 metabotropic glutamate receptors (mGluR's), that activate G protein-coupled phospholipase C (PLC) in a molecular signal-transduction mechanism that raises cytoplasmic Ca2+ and, when excessive, damages hippocampal neurons. Psychosine (beta-galactosylsphingosine), a cationic lysosphingolipid occurring naturally in nervous tissues, dose-dependently inhibited PLC activation induced by metabotropic alpha 1-adrenergic receptor signaling in cultured rat brain astrocytes in vitro. In the present study, we have tested neuroprotective efficacy of psychosine in vivo, in a rat model of glutamate excitotoxicity induced by intracerebroventricular (i.c.v.) administration of quisqualate. A sublethal i.c.v. dose of quisqualate caused episodes of prolonged akinesia and convulsions, and major damage to pyramidal neurons of the hippocampal CA1 and CA3 sector, but not to granule cell neurons of the dentate gyrus. Prior infusion of psychosine greatly attenuated quisqualate-induced behaviors, and fully prevented destruction by quisqualate of vulnerable hippocampal neurons. Psychosine may prove useful in prophylaxis of neurodegenerative disorders that arise from intensive hippocampal Group 1 mGluR stimulation.