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Background: Few studies, so far, have been specifically designed to highlight the features related to Compulsory Admissions (CA) and Voluntary Admissions (VA) in Italian psychiatric emergency wards. Aims: The main purpose of this observational study was to compare the sociodemographic and clinical characteristics of VA and CA and to explore possible predictors of re-admissions. Methods: During a 6-month Index Period (February, the 1st–July, the 31st 2008) all psychiatric admissions were documented and then followed-up through all available informatic systems for the next 9 years. Results: Out of 390 hospitalizations, 101 (25.9%) were compulsory (CA rate was 2.79 per 10,000 inhabitants per year, mean duration of hospitalizations of 7.33 ± 7.84 days). Diagnoses were recorded for the 325 patients who had been hospitalized during index period: schizophrenic psychoses ([ p = .042], in particular schizophrenia [ p = .027]), manic episode ( p = .044), and delusional disorders ( p = .009) were associated with CA; conversely, the diagnosis of unipolar major depression ( p = .005) and personality disorders ( p = .048) were significantly more frequent in VA. The 325 admitted patients were followed up for 1,801 person-years. No significant differences were found in terms of drop-outs, transferring, and discharge rates, and mortality rates due to both natural causes and suicides. Factors associated with at least one compulsory readmission were younger age and having had a previous CA ( p = .011); conversely having been engaged with psychiatric services for over 1 year prior to index hospitalization was protective for a subsequent CA ( p = .013). Conclusions: After a 40-year old political reform, the current study shows that, in a context of integrated outpatient and inpatient services, engagement with outpatient care may be protective for compulsory rehospitalization.

Objective: Psychiatric morbidity, impulsive behaviour and use of dysfunctional and maladaptive defences are core features of personality disorder (PD). This study aims to evaluate the significance of the strength of the association between these three core dimensions and PD. Method: Using a cross-sectional design, a sample of co-morbid Axis-I &-II disorders, and a sample of Axis-I disorders with no co-morbid PD were recruited at three general psychiatric mental health resource centres and then compared. PD as dependent variable was analysed both as a categorical and as a dimensional entity using the Structured Clinical Interview for DSM-IV. The Symptoms Checklist 90-R general severity index (GSI), the Barratt Impulsivity Scale (BIS) and the Defense Style Questionnaire (DSQ) were used to measure severity of psychiatric morbidity, impulsivity and defensive style, respectively. Results: BIS was a highly significant predictor of categorical PD (β = .13, SE = .03, p < .001), but not GSI and DSQ. BIS and GSI significantly predicted PD as a dimensional construct (β = 0.32, SE = .08, t = 4.05, p < 0.001; and β = 5.04, SE = 1.54, t = 3.28, p = 0.002, respectively). The diagnostic efficiency statistics found that BIS had greater sensitivity (.82) and specificity (.79), and overall predictive power (.87) of correctly identifying true positive and true negative PD diagnosis compared to the other two measures. Conclusions: BIS may be used in routine clinical practice as a screening measure to identify the presence of PD in complex presentations.

ETS domain-containing protein-1 (ELK1) is a transcriptional repressor important in regulating αvβ6 integrin expression. αvβ6 integrins activate the profibrotic cytokine Transforming Growth Factor β1 (TGFβ1) and are increased in the alveolar epithelium in Idiopathic Pulmonary Fibrosis (IPF). IPF is a disease associated with ageing and therefore we hypothesised that aged animals lackingElk1globally would develop spontaneous fibrosis in organs where αvβ6-mediated TGFβ activation has been implicated.Here we identify thatElk1-knockout (Elk1-/0) mice aged to one year developed spontaneous fibrosis in the absence of injury in both the lung and the liver but not in the heart or kidneys. The lungs ofElk1-/0aged mice demonstrated increased collagen deposition, in particular collagen 3α1, located in small fibrotic foci and thickened alveolar walls. Despite the liver having relatively low global levels of ELK1 expression,Elk1-/0animals developed hepatosteatosis and fibrosis. The loss ofElk1also had differential effects onItgb1, Itgb5andItgb6genes expression in the four organs potentially explaining the phenotypic differences in these organs. To understand the potential causes of reduced ELK1 in human disease we exposed human cells and murine lung slices to cigarette smoke extract which lead to reduced ELK1 expression which may explain the loss of ELK1 in human disease.These data support a fundamental role for ELK1 in protecting against the development of progressive fibrosis via transcriptional regulation of beta integrin subunit genes, and demonstrate that loss of ELK1 can be caused by cigarette smoke.

ETS domain-containing protein-1 (ELK1) is a transcriptional repressor important in regulating αvβ6 integrin expression. αvβ6 integrins activate the profibrotic cytokine Transforming Growth Factor β1 (TGFβ1) and are increased in the alveolar epithelium in idiopathic pulmonary fibrosis (IPF). IPF is a disease associated with aging and therefore we hypothesised that aged animals lacking Elk1 globally would develop spontaneous fibrosis in organs where avb6 mediated TGFb activation has been implicated. Here we identify that Elk1-knockout (Elk1(−/0)) mice aged to one year developed spontaneous fibrosis in the absence of injury in both the lung and the liver but not in the heart or kidneys. The lungs of Elk1(−/0) aged mice demonstrated increased collagen deposition, in particular collagen 3α1, located in small fibrotic foci and thickened alveolar walls. Despite the liver having relatively low global levels of ELK1 expression, Elk1(−/0) animals developed hepatosteatosis and fibrosis. The loss of Elk1 also had differential effects on Itgb1, Itgb5 and Itgb6 genes expression in the four organs potentially explaining the phenotypic differences in these organs. To understand the potential causes of reduced ELK1in human disease Finally we exposed human cells and murine lung slices to cigarette smoke extract which lead to reduced ELK1 expression which may explain the loss of ELK1 in human disease. These data support a fundament role for ELK1 in protecting against the development of progressive fibrosis via transcriptional regulation of beta integrin subunit genes, and demonstrate that loss of ELK1 can be caused by cigarette smoke.

Background Sleep reduction or enhancement is frequently observed with second-generation antidepressant treatments, and they can be beneficial or harmful depending on the symptom profile of each subject. Nevertheless, relatively little attention has been given so far to rank those effects across compounds. The aim of this meta-analysis is to provide quantitative data about short-term rates of insomnia and somnolence associated with 14 second-generation antidepressants during the treatment of major depression. Methods A literature search and a search of unpublished documents were performed. Eligible studies focusing on MD patients treated with second-generation antidepressants were entered in the analysis. Our primary outcome measures were insomnia and somnolence rates induced by antidepressants as compared with those associated with placebo. Sensitivity analyses were carried out as well. Results Ten second-generation antidepressants showed higher rates of insomnia than placebo. The highest incidence was found for bupropion and desvenlafaxine. Agomelatine was the only antidepressant with a lower likelihood of inducing insomnia than placebo. Eleven antidepressants were associated with higher rates of somnolence than placebo. Fluvoxamine and mirtazapine showed the highest frequency of somnolence. Bupropion induced somnolence to a lower extent than placebo. Sensitivity analyses showed a degree of variation of those findings. Discussion Antidepressants are associated with different insomnia and somnolence rates, mainly depending on their mechanisms of action. Despite some limitations, we underscore that the treatment-emergent insomnia and/or somnolence are frequent, and they could be used in clinical practice to face the specific needs of each patient.

Rationale Idiopathic pulmonary fibrosis is a chronic fibroproliferative disease with a median survival of approximately 3 years. αvβ6 integrins are upregulated in lung fibrosis and are associated with increased activation of the profibrotic cytokine TGF-β. The transcription factor Elk1 can repress gene expression of β6. We therefore hypothesise that animals lacking functional Elk1 (Elk1-/0) will develop age related pulmonary fibrosis. Methods Elk1 knock-out (Elk1-/0) and wild-type (Elk1+/0) mice were allowed to age for 365 days. At 365 days old mice were sacrificed and their lungs harvested for evaluation of collagen gene expression, lung hydroxyproline concentration and histological assessment. Results Lungs were extracted and lung wet weights were measured in Elk1-/0 mice and wild-type (Elk1+/0) controls and no significant difference between the two genotypes was shown (175.7 mg, 161.8 mg respectively n=6–8). However, assessment of total lung hydroxyproline established that there was significantly more hydroxyproline in Elk1-/0 mice compared with Elk1+/0 controls (852.3, 758.4 µg/lung set, respectively, n=5–8, p=0.0346). Assessment of Masson’s trichrome stained Elk1-/0 lung tissue sections found a small number of fibrotic lesions were present. Furthermore, there was a trend towards increased alveolar wall median thickness in Elk1-/0 mice compared with Elk1+/0 animals (5.94 vs 5.56 µm respectively). In a small number of 12 week old mice we identified a trend towards increased α-smooth muscle actin (αSMA) mRNA expression in the lungs of Elk1-/0 mice compared with Elk1+/0 controls (9.40, 2.24 median relative expression, respectively n=3). We therefore performed immunohistochemical staining for αSMA in the lungs of mice aged to 1 year and demonstrated visible increases in expression of αSMA in the alveolar epithelium of Elk1-/0 mice but not in Elk1+/0 controls. Conclusion These data suggest that Elk1 gene deletion result in age-related early fibrotic changes associated with the development of pulmonary fibrosis.

The gene coding for the catechol-O-methyltransferase (COMT) and the one coding for the dopamine receptor 2 (DRD2) have been linked with major depression (MD) and with the response to antidepressants in several studies. However, contrasting findings have been reported as well. The aim of the present study is, therefore, to investigate possible influences of rs4680 within COMT and rs6276 within DRD2, analyzed both individually and in combination, on the diagnosis and clinical outcomes in a sample of Korean MD patients treated with antidepressants.Totally, 184 Korean in-patients suffering from MD treated with either paroxetine or venlafaxine and 220 healthy control subjects were included in the present study. Depression severity was assessed by means of the Hamilton Rating Scale for Depression.We were not able to find any association between the two variants under investigation and diagnosis of MD, as well as with antidepressant response.Although limited by several factors, including the small sample size and the impossibility to extend our findings to patients treated with different antidepressants, the results of our study provide support to the notion that these variants might not play a major role in the etiology and clinical outcomes of MD.

Environmental and genetic factors contribute to the development of posttraumatic stress disorder (PTSD). Variation in the 5-HTTLPR polymorphism of the serotonin transporter gene has been hypothesized to affect risk for PTSD. With the aim of investigating this association, we conducted a meta-analysis to shed light on prior controversial results and increase statistical power to detect smaller effect sizes. PubMed and ISI databases were searched for studies published until December 2012. Twelve studies have been included, all based on trauma-exposed samples. Data were analyzed with Cochrane Collaboration Review Manager Software (Version 5). Quality and publication bias were assessed. Metaregressions were performed using Comprehensive Meta-Analysis software, Version 2. Taking into account all studies, no association was found between 5-HTTLPR and PTSD (p = .10), with evidence of between-study heterogeneity, which could be partly explained by gender differences. In sensitivity analyses, we found an association between SS genotype and PTSD in high trauma-exposed participants (p < .001). To be a carrier of the SS genotype seems to represent a risk factor for PTSD in high trauma exposure. Further studies focusing on Gene × Environment interactions are needed to better understand the role of this polymorphism in PTSD.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with high mortality. Active TGFβ1 is considered central to the pathogenesis of IPF. A major mechanism of TGFβ1 activation in the lung involves the epithelially restricted αvβ6 integrin. Expression of the αvβ6 integrin is dramatically increased in IPF. How αvβ6 integrin expression is regulated in the pulmonary epithelium is unknown. Here we identify a region in the β6 subunit gene (ITGB6) promoter acting to markedly repress basal gene transcription, which responds to both the Ets domain-containing protein Elk1 (Elk1) and the glucocorticoid receptor (GR). Both Elk1 and GR can regulate αvβ6 integrin expression in vitro. We demonstrate Elk1 binding to the ITGB6 promoter basally and that manipulation of Elk1 or Elk1 binding alters ITGB6 promoter activity, gene transcription, and αvβ6 integrin expression. Crucially, we find that loss of Elk1 causes enhanced Itgb6 expression and exaggerated lung fibrosis in an in vivo model of fibrosis, whereas the GR agonist dexamethasone inhibits Itgb6 expression. Moreover, Elk1 dysregulation is present in epithelium from patients with IPF. These data reveal a novel role for Elk1 regulating ITGB6 expression and highlight how dysregulation of Elk1 can contribute to human disease.

In vivo induction of the Escherichia coli lactose operon as a function of inducer concentration generates a sigmoidal curve, indicating a non-linear response. Suggested explanations for this dependence include a 2:1 inducer-repressor stoichiometry of induction, which is the currently accepted view. It is, however, known for decades that, in vitro, operator binding as a function of inducer concentration is not sigmoidal. This discrepancy between in vivo and in vitro data has so far not been resolved. We demonstrate that the in vivo non-linearity of induction is due to cooperative repression of the wild-type lac operon through DNA loop formation. In the absence of DNA loops, in vivo induction curves are hyperbolic. In the light of this result, we re-address the question of functional molecular inducer-repressor stoichiometry in induction of the lac operon.

The present study aimed to explore whether four single nucleotide polymorphisms (SNPs) within the AHI1 gene could be associated with schizophrenia (SCZ) and whether they could predict the clinical outcomes in SCZ patients treated with antipsychotics. Four hundred twenty-six (426) in-patients with SCZ and 345 controls were genotyped for four AHI1 SNPs (rs11154801, rs7750586, rs9647635 and rs9321501). Baseline and clinical measures for SCZ patients were assessed through the Positive and Negative Syndrome Scale (PANSS). Allelic and genotypic frequencies in SCZ subjects were compared with those of controls using the chi(2) statistics. The repeated-measure ANOVA was used for the assessment of treatment outcomes measured by PANSS changes. The case-control analysis did not show any difference in the genotypic distribution of the SNPs, while in the allelic analysis, a weak association was found between the rs9647635 A allele and SCZ. Furthermore, in the haplotype analysis, three haplotypes resulted in being associated with SCZ. On the other hand, two SNPs (rs7750586 and rs9647635) were associated with clinical improvement of negative symptoms in the allelic analysis, although in the genotypic analysis, only trends of association were found for the same SNPs. Our findings suggest a possible influence of AHI1 variants on SCZ susceptibility and antipsychotic response, particularly concerning negative symptomatology. Subsequent well-designed studies would be mandatory to confirm our results due to the methodological shortcomings of the present study.

BACKGROUND: One of the major challenges for research in the field of human aggression is the need to define the role of personality and trait-like dimensions, such as impulsivity and aggressiveness, in predisposing to violent behavior. AIMS: 1) To determine whether trait- aggressiveness and impulsivity may be associated with socio-demographic, clinical and crime history variables in a sample of male prisoners; 2) to detect any association of those traits with measures of early traumatic experiences and current resilience traits. METHODS: A sample of male prisoners (n = 1356) underwent the Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA) and the Barratt Impulsivity Scale (BIS). Axis I psychiatric disorders were also assessed. Early traumatic experiences and psychological resilience were detected respectively by the Childhood Trauma Questionnaire (CTQ) and the Connor-Davidson Resilience Scale (CD-RISC). Two non-linear logistic regression models were performed to test for the best predictors of trait-aggressiveness and impulsivity. RESULTS: Subjects with a history of substance use disorders and self-mutilation reported both higher BGLHA and BIS scores. Axis I disorders and suicide attempts were associated with aggressiveness, but not to impulsivity. A consistent correlation was found between BGLHA scores and early traumatic experiences. Resilience was positively correlated to impulsivity but not to aggressiveness scores. CONCLUSIONS: Our results support the view that aggressiveness and impulsivity are two different, albeit related trait-like dimensions of personality, having a different relationship with resilience, and, inferentially, a different impact over the development of psychiatric disorders.

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LXR alpha (liver X receptor, also called RLD-1) is a nuclear receptor, highly expressed in tissues that play a role in lipid homeostasis. In this report we show that fatty acids are positive regulators of LXR alpha gene expression and we investigate the molecular mechanisms underlying this regulation. In cultured rat hepatoma and primary hepatocyte cells, fatty acids and the sulfur-substituted fatty acid analog, tetradecylthioacetic acid, robustly induce LXR alpha (up to 3.5- and 7-fold, respectively) but not LXR beta (also called OR-1) mRNA steady state levels, with unsaturated fatty acids being more effective than saturated fatty acids. RNA stability and nuclear run-on studies demonstrate that changes in the transcription rate of the LXR alpha gene account for the major part of the induction of LXR alpha mRNA levels. A similar induction of protein level was also seen after treatment of primary hepatocytes with the same fatty acids. Consistent with such a transcriptional effect, transient transfection studies with a luciferase reporter gene, driven by 1.5 kb of the 5'-flanking region of the mouse (m)LXR alpha gene, show a peroxisome proliferator-activated receptor-alpha-dependent increase in luciferase activity upon treatment with tetradecylthioacetic acid and the synthetic peroxisome proliferator-activated receptor-alpha activator, Wy 14.643, suggesting that the mLXR alpha 5'-flanking region contains the necessary sequence elements for fatty acid responsiveness. In addition, in vivo LXR alpha expression was induced by fatty acids, consistent with the in vitro cell culture data. These observations demonstrate that LXR alpha expression is controlled by fatty acid signaling pathways and suggest an important cross-talk between fatty acid and cholesterol regulation of lipid metabolism.

The nuclear orphan receptor OR1 has been shown to bind as a heterodimer with retinoid X receptor (RXR) to direct repeat 4 (DR4) response elements. It remained unclear, however, whether this represents the only or the optimal binding site for this receptor. Therefore, we performed a DNA binding site selection assay that allows the identification of novel DNA binding sites for OR1 in an unbiased manner. While OR1 alone was not able to select a specific sequence from the pool of oligonucleotides, the OR1/RXR heterodimer selected a highly conserved DR1 element, termed DR1s, with two AGGTCA motifs spaced by one adenosine. The functional activity of the consensus binding site was verified in transient transfection assays and corroborated by in vitro studies. Based on the sequence of the consensus DR1s, we located putative natural binding sites in the 5'-promoter flanking regions of the rat S14 gene and the rat cholecystokinin type A receptor gene. Furthermore, we could show that although the OR1/RXR heterodimer has a distinct binding orientation on a DR4 element, it is able to bind in both orientations to the DR1s element. The OR1 paralog LXRalpha does not bind as a heterodimer with RXR to the DR1s element, indicating that these receptors, despite their homology, are involved in the regulation of different sets of genes.

Among the several genes associated with late-onset Alzheimer’s disease (LOAD), recently, Sirtuin genes have roused a growing interest because of their involvement in metabolic homeostasis and in brain aging. Particularly SIRT2 gene has been associated with Alzheimer’s disease (AD) as well as with mood disorders. The aim of this study is to investigate the possible associations between Sirtuin 2 gene (SIRT2) rs10410544 polymorphism and AD as well as depression in AD. In addition, we performed some exploratory analyses to investigate possible associations between the rs10410544 genotype and clinical features. We investigated these associations in two independent samples: the first one was composed of 275 Greek inhabitants and 117 patients; the second sample counted 181 Italian people and 43 patients. All patients were affected by LOAD. We failed to find any association between rs10410544 genotype and AD in the two samples. On the other hand, we found an association between the single nucleotide polymorphism (SNP) and depressive symptomatology (in the total sample p = 0.002), which was modulated by the tumor necrosis factor (TNF) values. Particularly, TT genotype seems to be protective versus depression. Finally, in the exploratory analyses, we found that the TT genotype was associated with earlier AD onset and a longer duration of the illness. In conclusion, we confirmed the association between SIRT2 gene and mood disturbances, although in AD patients. Further, we provided evidence that the TT genotype may be protective versus depressive symptoms, allowing an easier and thus earlier diagnosis of AD. This awareness may lead to a more detailed approach to these patients concerning diagnosis and therapy.

Background: Patients with major depression (MD) show reduced social adjustment when compared with healthy controls. However, even among treatment responders, significant differences in social adjustment occur. The main aim of the present work is to study several socio-demographic and clinical variables possibly influencing social adjustment in MD patients who responded to treatment. Methods: Two hundred and eleven MD patients experiencing a depressive episode who responded to their current treatment were recruited within the context of a large European multicentre project. Our primary outcome measure was the association between 19 socio-demographic and clinical variables and total social adjustment scores, as measured with the Social Adjustment Scale (SAS). Secondary outcome measures included the associations between the same variables and SAS sub-scales, and the associations between these variables and self-esteem, as measured with the Rosenberg Self-Esteem Scale. Results: A co-morbidity with anxiety disorders and the severity of residual depression symptoms were the strongest independent factors associated with poorer social adjustment, in terms of total and most sub-areas' SAS scores. Other variables associated with total and sub-areas' SAS scores were identified as well, although some variations across different areas were observed. Limitations: The cross-sectional design, the retrospective assessment of data and the lack of a placebo control group. Conclusions: Our results confirm that a co-morbidity with anxiety disorders and higher residual depression symptoms could reduce social adjustment among responder MD patients. Further longitudinal studies are needed to confirm our results. (C) 2013 Elsevier B.V. All rights reserved.

Substitution of the C-terminal leucine heptad repeat region of the normally tetrameric lactose repressor by the leucine heptad repeat dimerization domain of GCN4 protein resulted in cell extracts containing protein, designated R3, which behaved as a dimer based on gel retardation analysis of DNA binding (Alberti, S., Oehler, S., von Wilcken-Bergmann, B., and Müller-Hill, B. (1993) EMBO J. 12, 3227-3236). We have purified this R3 protein and characterized its properties in comparison with the wild-type repressor. R3 protein elutes from a molecular sieve with a Stokes radius characteristic of a dimer and a deduced molecular mass of 66 kDa. Unlike other dimeric repressors, produced by deletion or mutation in the leucine heptad repeat region, which display reduced apparent operator affinity, R3 binds to operator DNA sequences with wild-type equilibrium and kinetic properties. Although inducer affinity at neutral pH is similar for R3 and wild-type protein, at elevated pH the R3 protein undergoes a slightly smaller decrease in affinity and exhibits minimal cooperativity in sugar binding compared with the wild-type protein. Interestingly, in the presence of operator DNA, a state in which inducer binding to wild-type repressor is also of reduced affinity and slightly cooperative, R3 binding affinity is decreased to a greater extent, and the protein displays higher cooperativity than wild-type repressor. Consistent with inducer binding data in the presence of operator, the release of operator from R3 protein requires a higher sugar concentration than wild-type protein. These results are interpreted in the context of alterations involving the subunit interface which affect the allosteric behavior of the repressor protein.

The transcription factor serum response factor (SRF) plays a crucial role in the development of several organs. However, its role in the skin has not been explored. Here, we show that keratinocytes in normal human and mouse skin expressed high levels of SRF but that SRF expression was strongly downregulated in the hyperproliferative epidermis of wounded and psoriatic skin. Keratinocyte-specific deletion within the mouse SRF locus during embryonic development caused edema and skin blistering, and all animals died in utero. Postnatal loss of mouse SRF in keratinocytes resulted in the development of psoriasis-like skin lesions. These lesions were characterized by inflammation, hyperproliferation, and abnormal differentiation of keratinocytes as well as by disruption of the actin cytoskeleton. Ultrastructural analysis revealed markedly reduced cell-cell and cell-matrix contacts and loss of cell compaction in all epidermal layers. siRNA-mediated knockdown of SRF in primary human keratinocytes revealed that the cytoskeletal abnormalities and adhesion defects were a direct consequence of the loss of SRF. In contrast, the hyperproliferation observed in vivo was an indirect effect that was most likely a consequence of the inflammation. These results reveal that loss of SRF disrupts epidermal homeostasis and strongly suggest its involvement in the pathogenesis of hyperproliferative skin diseases, including psoriasis.

Serum response factor (SRF), is a crucial transcription factor for murine embryonic development and for the function of muscle cells and neurons. Gene expression data show that SRF and its transcriptional cofactors are also expressed in lymphocyte precursors and mature lymphocytes. However, the role of SRF in lymphocyte development has not been addressed in vivo so far, attributed in part to early embryonic lethality of conventional Srf-null mice. To determine the in vivo role of SRF in developing lymphocytes, we specifically inactivated the murine Srf gene during T or B cell development using lymphocyte-specific Cre transgenic mouse lines. T cell-specific Srf deletion led to a severe block in thymocyte development at the transition from CD4/CD8 double to single positive stage. The few residual T cells detectable in the periphery retained at least one functional Srf allele, thereby demonstrating the importance of SRF in T cell development. In contrast, deletion of Srf in developing B cells did not interfere with the growth and survival of B cells in general, yet led to a complete loss of marginal zone B cells and a marked reduction of the CD5+ B cell subset. Our study also revealed a contribution of SRF to the expression of the surface molecules IgM, CD19, and the chemokine receptor 4 in B lymphocytes. We conclude that SRF fulfills essential and distinct functions in the differentiation of different types of lymphocytes.

Background & Aims: SRF (Serum Response Factor), a widely expressed transcription factor, controls expression of mitogen-responsive and muscle-specific genes, thereby regulating the contractile actin microfilament. Genetic Srf deletion studies showed SRF to be indispensable for in vivo skeletal and cardiac muscle cell development. We now investigated for the first time in vivo SRF functions in smooth muscle cells of adult mice. Methods: We conditionally deleted a floxed Srf allele (Srfflex1) in adult mice by inducible activation of the CreERT2 recombinase expressed specifically in smooth muscle cells. Tamoxifen-induced CreERT2 activity stimulated deletion of exon 1 coding sequences of Srfflex1, thereby abolishing full-length SRF protein expression in adult smooth muscle cells of the analyzed organs: colon, bladder, and stomach. Results: Smooth muscle cell–specific ablation of full-length SRF protein in adult mice showed impaired contraction of intestinal smooth muscle, resulting in defective peristalsis. Mutant mice died within 2 weeks of tamoxifen treatment, displaying clear symptoms of ileus paralyticus. Cultured primary SRF-deficient colon smooth muscle cells were viable, but displayed drastic structural alterations and elevated senescence, paralleled by degeneration of the actin microfilament and impaired expression of smooth muscle–specific genes. Conclusions: SRF plays a vital role in the contractile activity and cytoskeletal architecture of adult smooth muscle cells and is therefore essential for physiologic functions of the gastrointestinal tract in vivo. Our mouse genetic model may resemble features of human chronic intestinal pseudo-obstruction.

Higher organisms rely on multiple modes of memory storage using the hippocampal network, which is built by precisely orchestrated mechanisms of axonal outgrowth, guidance and synaptic targeting. We demonstrate essential roles of the transcription factor serum response factor (SRF), a sensor of cytoskeletal actin dynamics, in all these processes. Conditional deletion of the mouse Srf gene reduced neurite outgrowth and abolished mossy fiber segregation, resulting in ectopic fiber growth inside the pyramidal layer. SRF-deficient mossy fibers aberrantly targeted CA3 somata for synapse formation. Axon guidance assays showed that SRF was a key mediator of ephrin-A and semaphorin guidance cues; in SRF-deficient neurons, these resulted in the formation of F-actin-microtubule rings rather than complete growth cone collapse. Dominant-negative variants of the SRF cofactor megakaryocytic acute leukemia (MAL) severely impeded neurite outgrowth and guidance. These data highlight essential links between SRF-mediated transcription and axon guidance and circuit formation in the hippocampus.

The central nervous system is fundamentally dependent on guided cell migration, both during development and in adulthood. We report an absolute requirement of the transcription factor serum response factor (SRF) for neuronal migration in the mouse forebrain. Conditional, late-prenatal deletion of Srf causes neurons to accumulate ectopically at the subventricular zone (SVZ), a prime neurogenic region in the brain. SRF-deficient cells of the SVZ exhibit impaired tangential chain migration along the rostral migratory stream into the olfactory bulb. SVZ explants display retarded chain migration in vitro . Regarding target genes, SRF deficiency impairs expression of the β-actin and gelsolin genes, accompanied by reduced cytoskeletal actin fiber density. At the posttranslational level, cofilin, a key regulator of actin dynamics, displays dramatically elevated inhibitory phosphorylation at Ser-3. Our studies indicate that SRF-controlled gene expression directs both the structure and dynamics of the actin microfilament, thereby determining cell-autonomous neuronal migration.

The transcription factor serum response factor (SRF) controls the expression of genes involved in cellular proliferation and differentiation. Interestingly, SRF also promotes cell survival by regulating the expression of antiapoptotic genes. In in vitro differentiating murine embryonic stem (ES) cells, SRF deficiency leads to increased apoptosis. Loss of SRF correlates with impaired expression of the antiapoptotic Bcl-2 and Bcl-xl genes. SRF binds the Bcl-2 promoter in vivo and activates Bcl-2 transcription. Reconstituting Bcl-2 in Srf(−/−) ES cells rescues these cells from apoptosis, demonstrating that SRF-dependent Bcl-2 expression is critical for ES cell survival. At the multicellular level, SRF deficiency leads to impaired cavitation and reduced Bcl-2 expression in embryoid bodies (EBs) and inappropriate apoptosis in both EBs and pregastrulation mouse embryos. Thus, our data from genetic and cellular studies uncover SRF-regulated Bcl-2 expression as a novel mechanism that is important for cell survival during early murine embryogenesis.

Background— The nature of some of the target genes for liver X receptors (LXRs)-α and -β, such as sterol regulatory element binding protein-1 and ATP-binding cassette transporter proteins, suggests a pivotal role of these nuclear receptors in the regulation of fatty acid and cholesterol homeostasis. The present study aimed to elucidate the physiological relevance of both LXRs with regard to lipid metabolism and macrophage cholesterol efflux. Methods and Results— Mice depleted for LXRα, LXRβ, or both were fed low-fat rodent chow for 18 months before investigations. The combined deficiency of LXRα and LXRβ was linked to impaired triglyceride metabolism, increased LDL and reduced HDL cholesterol levels, and cholesterol accumulation in macrophages (foam cells) of the spleen, lung, and arterial wall. Conclusions— Our data demonstrate the physiological importance of both LXRs in lipid metabolism and strongly indicate that both LXRs have a protective role against the development of atherosclerosis.

Objective The present study aimed to explore whether 4 single nucleotide polymorphisms (SNPs) within the AHI1 gene could be associated with major depressive disorder (MD) and bipolar disorder (BD), and whether they could predict clinical outcomes in mood disorders. Methods One hundred and eighty-four (184) patients with MD, 170 patients with BD and 170 healthy controls were genotyped for 4 AHI1 SNPs (rs11154801, rs7750586, rs9647635 and rs9321501). Baseline and final clinical measures for MD patients were assessed through the Hamilton Rating Scale for Depression (HAM-D). Allelic and genotypic frequencies in MD and BD subjects were compared with those of each disorder and healthy group using the χ(2) statistics. Repeated measures ANOVA was used to test possible influences of SNPs on treatment efficacy. Results The rs9647635 A/A was more represented in subjects with BD as compared with MD and healthy subjects together. The rs9647635 A/A was also more presented in patients with MD than in healthy subjects. With regard to the allelic analysis, rs9647635 A allele was more represented in subjects with BD compared with healthy subjects, while it was not observed between patients with MD and healthy subjects. Conclusion Our findings provide potential evidence of an association between some variants of AHI1 and mood disorders susceptibility but not with clinical outcomes. However, we will need to do more adequately-powered and advanced association studies to draw any conclusion due to clear limitations.

The nuclear oxysterol-receptor paralogues LXRalpha and LXRbeta share a high degree of amino acid identity and bind endogenous oxysterol ligands with similar affinities. While LXRalpha has been established as an important regulator of cholesterol catabolism in cholesterol-fed mice, little is known about the function of LXRbeta in vivo. We have generated mouse lines with targeted disruptions of each of these LXR receptors and have compared their responses to dietary cholesterol. Serum and hepatic cholesterol levels and lipoprotein profiles of cholesterol-fed animals revealed no significant differences between LXRbeta(-/-) and wild-type mice. Steady-state mRNA levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase, farnesyl diphosphate synthase, and squalene synthase were increased in LXRbeta(-/-) mice compared with LXRbeta(+/+) mice, when fed standard chow. The mRNA levels for cholesterol 7alpha-hydroxylase, oxysterol 7alpha-hydroxylase, sterol 12alpha-hydroxylase, and sterol 27-hydroxylase, respectively, were comparable in these strains, both on standard and 2% cholesterol chow. Our results indicate that LXRbeta(-/-) mice - in contrast to LXRalpha(-/-) mice - maintain their resistance to dietary cholesterol, despite subtle effects on the expression of genes coding for enzymes involved in lipid metabolism. Thus, our data indicate that LXRbeta has no complete overlapping function compared with LXRalpha in the liver.

Oxysterols are important regulatory molecules of diverse biological processes such as cholesterol homeostasis, bile acid synthesis and apoptosis. Recent findings led to the suggestion that some of these functions are mediated by the nuclear receptors LXRalpha and LXRbeta owing to their potential to bind a group of naturally occurring oxysterols as their ligands. In this report, we compare the genomic structure and the promoter regions of the two mouse LXR genes. In addition, we show evidence for the presence of a processed, but truncated LXRbeta pseudogene in the mouse genome. RACE-PCR on mouse liver cDNA demonstrates the presence of more than one defined transcription initiation site for both genes. The LXRalpha and LXRbeta promoter regions are GC-rich and contain a number of putative Sp1 binding sites but lack obvious TATA and CAAT boxes. A database search revealed several sequence motifs in the LXR promoter regions that resemble known transcription factor binding sites. Most striking is the identification of one potential NFkappaB and seven potential Ets-protein binding sites in the LXRbeta promoter, suggesting an important role for this receptor in the haematopoietic/immune system.