Affective temperaments show stronger association with infertility treatment success compared to somatic factors, highlighting the role of personality focused interventions

Infertility has a multifactorial background, where, besides somatic factors, psychological contributors also play a role in development and outcome. While affective temperaments have been associated with development, course, and outcome as well as treatment success in various somatic conditions, their association with infertility and its treatment has not been investigated so far. The purpose of our retrospective cohort study was to evaluate the influence of affective temperaments on fertility treatment outcomes. Among 578 women who underwent infertility treatment in an Assisted Reproduction Centre in Budapest, Hungary, treatment success, detailed medical history, and demographic parameters were recorded, and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Auto-questionnaire (TEMPS-A) was administered. Possible predictors of assisted reproduction outcome were analyzed using multivariate logistic regression models, followed by a receiver operating curve (ROC) analysis in order to define ideal affective temperament cut-off values for clinical applicability. Aside from age, BMI, and previous miscarriage, cyclothymic scores > 4 (OR = 0.51 CI 0.35-0.74, p < 0.001), depressive scores > 9 (OR = 0.59 CI 0.4-0.87, p = 0.009) and anxious scores > 9 (OR = 0.45 CI 0.31-0.66, p < 0.001) significantly decreased the odds of clinical pregnancy by 49%, 41% and 55%, respectively. Irritable and hyperthymic temperaments, as well as other somatic and socio-economic factors had no effect on infertility treatment outcomes. The results suggest that affective temperaments may be related to the outcome of infertility treatments. Thus, screening for affective temperaments may help identify high-risk patient groups and offer patient-tailored treatment, which may increase the chances of a successful pregnancy and live birth for women undergoing IVF treatment.

[The role of psychological factors in the development and treatment of infertility]

Infertility can be caused by several factors, thus the effective treatment of infertility is a complex and multidisciplinary task. While psychological support is an essential part of infertility treatment, there is growing evidence that the role of psychological factors is much greater, as personality and psychological factors have a significant impact on the development, long-term course, and treatment success of several somatic diseases. Exploring the possible mechanisms through which these psychological factors directly or indirectly contribute to infertility and the success of infertility interventions could help identify high-risk patient groups and tailor treatment to the patient, which may increase the chances of successful pregnancy and live birth in women undergoing assisted reproductive treatment. In this review we aim to summarize current knowledge and research findings on the relationship between psychological factors and infertility treatments, including clinical consequences and implications for future research. Keywords: infertility, assisted reproduction, IVF, adherence, personality, temperaments, affective temperaments, TEMPS-A, stress, depression.

The development of systolic heart failure in case of pressure overload-induced left ventricular myocardial hypertrophy is associated with a unique microRNA expression profile in a rat model

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): New National Excellence Program of the Ministry of Human Capacities

Introduction

Growing body of evidence suggests that distinct alterations in myocardial microRNA (miRNA) expression contribute to pressure overload (PO)-induced pathological cardiac remodeling. Nevertheless, it is still under intense investigation whether the changes in miRNA expression patterns are also associated with the decompensation of LV systolic function in case of PO-evoked LV hypertrophy (LVH). Hence, we aimed to characterize miRNA expression in PO-induced LVH with and without systolic heart failure (HF).

Methods

PO was evoked by abdominal aortic banding (AB) in male Sprague-Dawley rats. Age-matched, sham-operated animals served as controls. Functional and morphological alterations were assessed by echocardiography and histology. At the end of the experimental period, rats in the AB group were subcategorized based on ejection fraction [EF] into ABLVH (EF&gt;40%) and ABHF groups (EF&lt;40%). Global miRNA expression profiling was performed using next generation sequencing. Bioinformatics analysis was carried out to predict miRNA-target interactions. Expression of selected target genes was measured by qRT-PCR.

Results

Increased heart weight-to-tibial length, LV mass and fibrosis confirmed the development of pathological LVH in both the ABLVH and ABHF groups. Nevertheless, increased lung weight-to-tibial length, chamber dilatation and severely reduced EF was noted only in the ABHF and not in the ABLVH, when compared to the sham group. 50 miRNA showed different expression in the ABHF compared to the ABLVH group. Based on the altered gene expression profile, in silico bioinformatics analysis predicted several target genes. Among them, reduced mRNA expression level of Fmr1 (FMRP translational regulator 1), Zfpm2 (zinc finger protein, multitype 2), Wasl (WASP like actin nucleation promoting factor), Ets1 (ETS proto-oncogene 1) and Atg16l1 (Autophagy Related 16 Like 1) was confirmed in ABHF compared to ABLVH.

Conclusions

Decompensation of systolic function in PO-induced LVH is associated with unique miRNA profile leading to specific regulation of gene expression.

[The relationship between therapeutic adherence and personality]

Inadequate adherence to long-term therapies significantly affects the course and outcome of the disease, and therefore poses a serious threat to both the effectiveness and success of treatment and the long-term well-being of patients. Therapeutic adherence is an extremely complex process, with a number of risk and protective factors identified, many of which underlie the psychological characteristics of the patient. A number of medication adherence models have been developed to take into account the psychological characteristics of patients, and recent research has examined the relationship between different personality models and adherence to therapeutic recommendations. In this review we aim to summarize current knowledge, adherence models, research findings on the relationship between personality and adherence, including implications for future research.

Sex-related differences in cardiac and myofilament function in rats with pressure-overload induced left ventricular hypertrophy

Introduction

Recent findings indicate that sex is a major determinant of left ventricular (LV) structure in pressure overload (PO)-induced LV myocardial hypertrophy (LVH). However, data are scare regarding sex-related differences in LV function in case of PO-evoked LVH.

Aim

Hence, in the present study we aimed at comprehensively investigating sex-related functional differences on the global cardiac level and also on the myofilament level in PO-induced LVH.

Method

Abdominal aortic banding (AB) was carried out to induce chronic PO for 6 or 12 weeks in male and female rats. Age- and sex-matched sham-operated animals served as controls. The development of LVH was followed by serial echocardiography. The extent of cardiomyocyte hypertrophy and myocardial fibrosis were evaluated by histology. Cardiac function was assessed by pressure-volume analysis. Force measurement was carried out in permeabilized cardiomyocytes to compute myofilament function.

Results

At week 6, robust myocardial hypertrophy, concentric LV geometry and moderate interstitial fibrosis were detected in both male and female AB rats. This early stage of PO-induced LVH was associated with increased LV contractility (slope of end-systolic pressure-volume relationship [ESPVR, mmHg/μl]: 3.09±0.18 Male-AB-wk6 vs. 1.79±0.22 Male-Sham-wk6 P&lt;0.05; 3.68±0.77 Female-AB-wk6 vs. 1.87±0.21 Female-Sham-wk6 P&lt;0.05) and enhanced myofilament Ca2+ sensitivity in both sexes (pCa50: 5.86±0.01 Male-AB-wk6 vs. 5.73±0.02 Male-Sham-wk6 P&lt;0.05; 5.94±0.03 Female-AB-wk6 vs. 5.73±0.01 Female-Sham-wk6 P&lt;0.05). At week 6, the augmented LV contractility effectively counterbalanced the increased afterload in both male and female AB groups. Hence, ventricular-arterial coupling (VAC) was maintained and LV systolic function was preserved in the AB groups in both sexes. In contrast, at week 12, marked sex differences could be observed. At this later stage, LVH was characterized by eccentric remodeling and intensified collagen accumulation in male AB rats. The initial LV contractility augmentation (slope of ESPVR, mmHg/μl: 1.74±0.13 Male-AB-wk12 vs. 1.31±0.17 Male-Sham-wk12 n.s.) as well as the enhanced myofilament Ca2+ sensitivity (pCa50: 5.78±0.02 Male-AB-wk12 vs. 5.75±0.01 Male-Sham-wk12 n.s.) diminished, leading to impaired VAC and reduced LV systolic function. On the contrary, in female AB rats, cardiac contractility (ESPVR, mmHg/ μl: 3.97±0.50 Female-AB-wk12 vs. 2.08±0.17 Female-Sham-wk12 P&lt;0.05) and myofilament Ca2+ sensitivity (pCa50:5.85±0.02 Female-AB-wk12 vs. 5.78±0.01 Female-Sham-wk12 P&lt;0.05) remained increased, resulting in adequate VAC and preserved LV systolic function at late-stage of PO-induced LVH as well.

Conclusion

The initially augmented LV contractility and enhanced myofilament Ca2+ sensitivity declines in male but not in female AB rats at later time points. Hence, characteristically different alterations occur in LV systolic function between the two sexes in late-stage of PO-evoked LVH.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): NVKP_16-1-2016-0017.

1206Doxapram is a promising new antiarrhythmic drug for an atrial-specific therapy of atrial fibrillation

Background

TASK-1 (K2P3.1) is an atrial-specific two-pore domain potassium channel that is significantly upregulated in atrial fibrillation (AF) patients resulting in shortened atrial action potential duration (APD). Inhibition of TASK-1 in human atrial cardiomyocytes reverses AF-related APD shortening to values observed in patients with sinus rhythm (SR). By in silico-modelling and experimental characterization of drug binding sites, doxapram was identified as specific inhibitor of TASK-1.

Purpose

In this study, we investigated the antiarrhythmic efficacy of doxapram in a porcine model of AF to convert and suppress AF.

Methods

We established a new porcine model of persistent AF without induced tachymyopathy. AF was induced in domestic pigs by intermittent atrial burst stimulation using implanted pacemakers. During AF episodes, burst stimulation was inhibited by an integrated pacemaker biofeedback algorithm. AV-node ablation was performed to prevent AF-associated heart failure. All pigs underwent catheter-based electrophysiological investigations prior to and after 14 days doxapram treatment. Pigs in the treatment group received intravenous applications of doxapram twice per day. Rhythm status was continuously recorded by intracardiac long-term ECG monitors. The application of doxapram for cardioversion and long term suppression of AF in pigs with persistent AF was evaluated. Subsequent to the doxapram treatment, porcine cardiomyocytes were isolated from right and left atria and electrophysiologically investigated by patch-clamp and multi-electrode experiments. Atrial electrical remodeling was characterized by analyses of ion channel expression at mRNA and protein levels.

Results

TASK-1 mRNA, protein and transmembrane current were significantly increased in AF pigs compared to SR controls, resulting in shortened atrial APDs. In doxapram-treated AF pigs the AF burden was significantly reduced. After 14 days treatment with doxapram, TASK-1 currents and atrial APDs recorded in porcine cardiomyocytes were reduced and similar to values of SR animals. Doxapram could be successfully applied for cardioversion in pigs with persistent AF. On average, cardioversion was observed 3 minutes after doxapram application.

Conclusion

Doxapram significantly suppressed AF episodes and normalized cellular electrophysiological characteristics in a porcine model of AF through inhibition of the TASK-1 ion channel. Furthermore, doxapram rapidly converted AF into SR in pigs. Therefore, doxapram might serve as a new antiarrhythmic drug to treat AF in patients.

P3454Myocardial reverse remodeling occurs to a comparable extent in male and female aortic-banded rats following pressure unloading

Background

Sex differences have been intensely investigated during the development of pressure overload (PO; e.g. aortic stenosis, arterial hypertension)-induced left ventricular (LV) myocardial hypertrophy (LVH). However, it is less clear whether sex-related differences also affect the regression of pathological LVH after pressure unloading.

Purpose

Therefore, we investigated the potential influential effect of sex on myocardial reverse remodeling in a relevant rat model of banding and debanding of the abdominal aorta.

Methods

PO of the left ventricle was induced in male (M) and female (F) rats by abdominal aortic banding (AB) for 6 or 12 weeks. Sham operated animals served as controls. Pressure unloading was evoked by removing the aortic constriction at week 6 (debanded). Serial echocardiography was performed to detect temporal alterations in LV morphology and geometry. Furthermore, distinct aspects of LV systolic and diastolic function were assessed by pressure-volume analysis. Structural changes, such as cardiomyocyte hypertrophy and interstitial fibrosis were measured on histological sections. Fetal gene expression (a molecular marker of pathological LVH) was analyzed by quantitative real-time PCR.

Results

In both male and female AB rats, PO induced the development of marked LVH as confirmed by increased LV mass, heart weight-to-tibial length ratio (HW/TL [g/cm]: 0.47±0.01 AB-M vs. 0.36±0.01 Sham-M, p<0.05; 0.36±0.02 AB-F vs. 0.26±0.01 Sham-F, p<0.05) and cardiomyocyte diameter. Similarly, reactivation of fetal gene expression (indicated by increased atrial natriuretic peptide [ANP]) and enhanced interstitial collagen accumulation was also observed in male and female AB groups as well. The extent of myocardial hypertrophy was greater among female AB animals, while fibrosis was more severe in male AB rats. In both genders, LVH was associated with prolonged ventricular relaxation (active relaxation time constant, Tau [ms]: 19.6±0.8 AB-M vs. 13.1±0.4 Sham-M, p<0.05; 15.2±1.3 AB-F vs. 12.2±0.3 Sham-F, p<0.05). However, systolic function was impaired only in males (ejection fraction, [%]: 44.4±2.3 AB-M vs. 57.5±2.1 Sham-M, p<0.05; 49.7±2.2 AB-F vs. 53.4±1.7 Sham-F, n.s.). Contrary to the sex-dependent differences during the development of LVH, removing the aortic constriction resulted in a comparable degree of reverse remodeling on the morphological (decreased LV mass, HW/TL), histological (decreased CD and interstitial fibrosis), molecular (reduced ANP expression) and functional (recovered ejection fraction and Tau) levels in both male and female rats.

Conclusion

Pressure unloading at a relatively early time point leads to myocardial reverse remodeling to a comparable degree in male and female rats.

Acknowledgement/Funding

NVKP-16-1-2016-0017; ÚNKP-18-3-I-SE-9

Elafibranor, an Agonist of the Peroxisome Proliferator-Activated Receptor-α and -δ, Induces Resolution of Nonalcoholic Steatohepatitis Without Fibrosis Worsening

BACKGROUND & AIMS

Elafibranor is an agonist of the peroxisome proliferator-activated receptor-α and peroxisome proliferator-activated receptor-δ. Elafibranor improves insulin sensitivity, glucose homeostasis, and lipid metabolism and reduces inflammation. We assessed the safety and efficacy of elafibranor in an international, randomized, double-blind placebo-controlled trial of patients with nonalcoholic steatohepatitis (NASH).

METHODS

Patients with NASH without cirrhosis were randomly assigned to groups given elafibranor 80 mg (n = 93), elafibranor 120 mg (n = 91), or placebo (n = 92) each day for 52 weeks at sites in Europe and the United States. Clinical and laboratory evaluations were performed every 2 months during this 1-year period. Liver biopsies were then collected and patients were assessed 3 months later. The primary outcome was resolution of NASH without fibrosis worsening, using protocol-defined and modified definitions. Data from the groups given the different doses of elafibranor were compared with those from the placebo group using step-down logistic regression, adjusting for baseline nonalcoholic fatty liver disease activity score.

RESULTS

In intention-to-treat analysis, there was no significant difference between the elafibranor and placebo groups in the protocol-defined primary outcome. However, NASH resolved without fibrosis worsening in a higher proportion of patients in the 120-mg elafibranor group vs the placebo group (19% vs 12%; odds ratio = 2.31; 95% confidence interval: 1.02-5.24; P = .045), based on a post-hoc analysis for the modified definition. In post-hoc analyses of patients with nonalcoholic fatty liver disease activity score ≥4 (n = 234), elafibranor 120 mg resolved NASH in larger proportions of patients than placebo based on the protocol definition (20% vs 11%; odds ratio = 3.16; 95% confidence interval: 1.22-8.13; P = .018) and the modified definitions (19% vs 9%; odds ratio = 3.52; 95% confidence interval: 1.32-9.40; P = .013). Patients with NASH resolution after receiving elafibranor 120 mg had reduced liver fibrosis stages compared with those without NASH resolution (mean reduction of 0.65 ± 0.61 in responders for the primary outcome vs an increase of 0.10 ± 0.98 in nonresponders; P < .001). Liver enzymes, lipids, glucose profiles, and markers of systemic inflammation were significantly reduced in the elafibranor 120-mg group vs the placebo group. Elafibranor was well tolerated and did not cause weight gain or cardiac events, but did produce a mild, reversible increase in serum creatinine (effect size vs placebo: increase of 4.31 ± 1.19 μmol/L; P < .001).

CONCLUSIONS

A post-hoc analysis of data from trial of patients with NASH showed that elafibranor (120 mg/d for 1 year) resolved NASH without fibrosis worsening, based on a modified definition, in the intention-to-treat analysis and in patients with moderate or severe NASH. However, the predefined end point was not met in the intention to treat population. Elafibranor was well tolerated and improved patients' cardiometabolic risk profile. ClinicalTrials.gov number: NCT01694849.

Patterns of impaired oral health-related quality of life dimensions

How dental patients are affected by oral conditions can be described with the concept of oral health-related quality of life (OHRQoL). This concept intends to make the patient experience measurable. OHRQoL is multidimensional, and Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact were suggested as its four dimensions and consequently four scores are needed for comprehensive OHRQoL assessment. When only the presence of dimensional impact is measured, a pattern of affected OHRQoL dimensions would describe in a simple way how oral conditions influence the individual. By determining which patterns of impact on OHRQoL dimensions exist in prosthodontic patients and general population subjects, we aimed to identify in which combinations oral conditions' functional, painful, aesthetical and psychosocial impact occurs. Data came from the Dimensions of OHRQoL Project with Oral Health Impact Profile (OHIP)-49 data from 6349 general population subjects and 2999 prosthodontic patients in the Learning Sample (N = 5173) and the Validation Sample (N = 5022). We hypothesised that all 16 patterns of OHRQoL dimensions should occur in these individuals who suffered mainly from tooth loss, its causes and consequences. A dimension was considered impaired when at least one item in the dimension was affected frequently. The 16 possible patterns of impaired OHRQoL dimensions were found in patients and general population subjects in both Learning and Validation Samples. In a four-dimensional OHRQoL model consisting Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact, oral conditions' impact can occur in any combination of the OHRQoL dimensions.

Exploratory factor analysis of the Oral Health Impact Profile

Although oral health-related quality of life (OHRQoL) as measured by the Oral Health Impact Profile (OHIP) is thought to be multidimensional, the nature of these dimensions is not known. The aim of this report was to explore the dimensionality of the OHIP using the Dimensions of OHRQoL (DOQ) Project, an international study of general population subjects and prosthodontic patients. Using the project's Learning Sample (n = 5173), we conducted an exploratory factor analysis on the 46 OHIP items not specifically referring to dentures for 5146 subjects with sufficiently complete data. The first eigenvalue (27·0) of the polychoric correlation matrix was more than ten times larger than the second eigenvalue (2·6), suggesting the presence of a dominant, higher-order general factor. Follow-up analyses with Horn's parallel analysis revealed a viable second-order, four-factor solution. An oblique rotation of this solution revealed four highly correlated factors that we named Oral Function, Oro-facial Pain, Oro-facial Appearance and Psychosocial Impact. These four dimensions and the strong general factor are two viable hypotheses for the factor structure of the OHIP.

Human monoclonal antibody MBL-HCV1 delays HCV viral rebound following liver transplantation: a randomized controlled study

Rapid allograft infection complicates liver transplantation (LT) in patients with hepatitis C virus (HCV). Pegylated interferon-α and ribavirin therapy after LT has significant toxicity and limited efficacy. The effect of a human monoclonal antibody targeting the HCV E2 glycoprotein (MBL-HCV1) on viral clearance was examined in a randomized, double-blind, placebo-controlled pilot study in patients infected with HCV genotype 1a undergoing LT. Subjects received 11 infusions of 50 mg/kg MBL-HCV1 (n=6) or placebo (n=5) intravenously with three infusions on day of transplant, a single infusion on days 1 through 7 and one infusion on day 14 after LT. MBL-HCV1 was well-tolerated and reduced viral load for a period ranging from 7 to 28 days. Median change in viral load (log10 IU/mL) from baseline was significantly greater (p=0.02) for the antibody-treated group (range -3.07 to -3.34) compared to placebo group (range -0.331 to -1.01) on days 3 through 6 posttransplant. MBL-HCV1 treatment significantly delayed median time to viral rebound compared to placebo treatment (18.7 days vs. 2.4 days, p<0.001). As with other HCV monotherapies, antibody-treated subjects had resistance-associated variants at the time of viral rebound. A combination study of MBL-HCV1 with a direct-acting antiviral is underway.

PARP inhibition in atherosclerosis and its effects on dendritic cells, T cells and auto-antibody levels

Objective

Atherosclerosis is a chronic inflammatory process. Poly(ADP-ribose) polymerase-1 (PARP), a nuclear enzyme linked to DNA repair, has been shown to be involved in atherogenesis; however, the effects on dendritic cells, T cells and serum auto-antibody levels are not fully understood.

Methods

Male Apoe^-/- mice on a western diet were treated with the PARP inhibitor 1NO-1001 (n = 15), while the control group (n = 15) received 5% glucose solution for 10 weeks.

Results

Inhibition of PARP markedly reduced atherosclerotic lesion development (p = 0.001). Immunohistochemistry and mRNA analysis revealed a reduced inflammatory compound inside the lesion. Focusing on dendritic cells, INO-1001 reduced number of cells (p = 0.04), grade of activation, represented by I/12 (p = 0.04) and Cd83 (p = 0.03), and grade of attraction, represented by Mip3α (p = 0.02) in the plaque. Furthermore, INO-1001 decreased number of T lymphocyte (p = 0.003) in the lesion and grade of activation after stimulation with oxLDL in vitro. Moreover, serum IgM antibody levels to oxLDL were significantly lower in INO-1001 treated mice (p = 0.03).

Conclusions

Functional blockade of PARP by INO-1001 reduces atherosclerotic lesion development. The anti-atherogenic effect is beside already known mechanisms also moderated due to modulation of DC and T cell invasion and activation, DC attraction as well as IgM antibody levels to oxLDL.

New pool of cortical interneuron precursors in the early postnatal dorsal white matter

The migration of cortical γ-aminobutyric acidergic interneurons has been extensively studied in rodent embryos, whereas few studies have documented their postnatal migration. Combining in vivo analysis together with time-lapse imaging on cortical slices, we explored the origin and migration of cortical interneurons during the first weeks of postnatal life. Strikingly, we observed that a large pool of GAD65-GFP-positive cells accumulate in the dorsal white matter region during the first postnatal week. Part of these cells divides and expresses the transcription factor paired box 6 indicating the presence of local transient amplifying precursors. The vast majority of these cells are immature interneurons expressing the neuronal marker doublecortin and partly the calcium-binding protein calretinin. Time-lapse imaging reveals that GAD65-GFP-positive neurons migrate from the white matter pool into the overlying anterior cingulate cortex (aCC). Some interneurons in the postnatal aCC express the same immature neuronal markers suggesting ongoing migration of calretinin-positive interneurons. Finally, bromodeoxyuridine incorporation experiments confirm that a small fraction of interneurons located in the aCC are generated during the early postnatal period. These results altogether reveal that at postnatal ages, the dorsal white matter contains a pool of interneuron precursors that divide and migrate into the aCC.

Kv3.1b and Kv3.3 channel subunit expression in murine spinal dorsal horn GABAergic interneurones

GABAergic interneurones, including those within spinal dorsal horn, contain one of the two isoforms of the synthesizing enzyme glutamate decarboxylase (GAD), either GAD65 or GAD67. The physiological significance of these two GABAergic phenotypes is unknown but a more detailed anatomical and functional characterization may help resolve this issue. In this study, two transgenic Green Fluorescent Protein (GFP) knock-in murine lines, namely GAD65-GFP and GAD67-GFP (Δneo) mice, were used to profile expression of Shaw-related Kv3.1b and Kv3.3 K(+)-channel subunits in dorsal horn interneurones. Neuronal expression of these subunits confers specific biophysical characteristic referred to as 'fast-spiking'. Immuno-labelling for Kv3.1b or Kv3.3 revealed the presence of both of these subunits across the dorsal horn, most abundantly in laminae I-III. Co-localization studies in transgenic mice indicated that Kv3.1b but not Kv3.3 was associated with GAD65-GFP and GAD67-GFP immunopositive neurones. For comparison the distributions of Kv4.2 and Kv4.3 K(+)-channel subunits which are linked to an excitatory neuronal phenotype were characterized. No co-localization was found between GAD-GFP +ve neurones and Kv4.2 or Kv4.3. In functional studies to evaluate whether either GABAergic population is activated by noxious stimulation, hindpaw intradermal injection of capsaicin followed by c-fos quantification in dorsal horn revealed co-expression c-fos and GAD65-GFP (quantified as 20-30% of GFP +ve population). Co-expression was also detected for GAD67-GFP +ve neurones and capsaicin-induced c-fos but at a much reduced level of 4-5%. These data suggest that whilst both GAD65-GFP and GAD67-GFP +ve neurones express Kv3.1b and therefore may share certain biophysical traits, their responses to peripheral noxious stimulation are distinct.

The unfolding web of innate immune dysregulation in alcoholic liver injury

Inflammatory cell and cytokine cascade activation is present in humans with alcoholic liver disease as well as in animal models of alcohol-induced liver damage. Gut-derived lipopolysaccharide (LPS), a ligand of the Toll-like receptor 4 (TLR4), plays a central role in triggering and maintaining activation of Kupffer cells in alcoholic hepatitis. In this mini-review, we describe molecular mechanisms that lead to increased inflammatory cell activation by alcohol and LPS and discuss the mechanism for activation in alcohol-exposed macrophages. In alcohol-induced liver disease we discuss the role of MyD88-independent but IRF3-mediated TLR4 signaling in alcohol-related liver inflammation and liver damage.

Developmental regulation of metabotropic glutamate receptor 1 splice variants in olfactory bulb mitral cells

Alternative splicing of the metabotropic glutamate receptor 1 (mGluR1) receptor gene generates two major receptor isoforms, mGluR1a and mGluR1b, differing in intracellular function and distribution. However, little is known on the expression profiles of these variants during development. We examined the mRNA expression profile of mGluR1a/b in microdissected layers and acutely isolated mitral cells in the developing mouse olfactory bulb. This analysis showed that the two mGluR1 variants are differentially regulated within each bulb layer. During the first postnatal week, the mGluR1a isoform replaces GluR1b in the microdissected mitral cell layer (MCL) and in isolated identified mitral cells, coinciding with a developmental epoch of mitral cell dendritic reorganization. Although mGluR1a mRNA is expressed at high levels in both the adult external plexiform layer (EPL) and MCL, Western blotting analysis reveals a marked reduction of the mGluR1a protein in the MCL, where mitral cell bodies are located, and strong labeling in the EPL, which contains mitral cell dendrites. This suggests that there is increased dendritic trafficking efficiency of the receptor in adult. The temporal and spatial shift in mGluR1b/a expression suggests distinct roles of the mGluR1 isoforms, with mGluR1b potentially involved in the early mitral cell maturation and mGluR1a in dendritic and synapse function.

Two GABAergic intraglomerular circuits differentially regulate tonic and phasic presynaptic inhibition of olfactory nerve terminals

Olfactory nerve axons terminate in olfactory bulb glomeruli forming excitatory synapses onto the dendrites of mitral/tufted (M/T) and juxtaglomerular cells, including external tufted (ET) and periglomerular (PG) cells. PG cells are heterogeneous in neurochemical expression and synaptic organization. We used a line of mice expressing green fluorescent protein under the control of the glutamic acid decarboxylase 65-kDa gene (GAD65+) promoter to characterize a neurochemically identified subpopulation of PG cells by whole cell recording and subsequent morphological reconstruction. GAD65+ GABAergic PG cells form two functionally distinct populations: 33% are driven by monosynaptic olfactory nerve (ON) input (ON-driven PG cells), the remaining 67% receive their strongest drive from an ON-->ET-->PG circuit with no or weak monosynaptic ON input (ET-driven PG cells). In response to ON stimulation, ON-driven PG cells exhibit paired-pulse depression (PPD), which is partially reversed by GABA(B) receptor antagonists. The ON-->ET-->PG circuit exhibits phasic GABA(B)-R-independent PPD. ON input to both circuits is under tonic GABA(B)-R-dependent inhibition. We hypothesize that this tonic GABA(B)R-dependent presynaptic inhibition of olfactory nerve terminals is due to autonomous bursting of ET cells in the ON-->ET-->PG circuit, which drives tonic spontaneous GABA release from ET-driven PG cells. Both circuits likely produce tonic and phasic postsynaptic inhibition of other intraglomerular targets. Thus olfactory bulb glomeruli contain at least two functionally distinct GABAergic circuits that may play different roles in olfactory coding.