DIFFERENTIAL EXPRESSION OF GLUTARYL-CoA DEHYDROGENASE IN ADULT RAT CNS, PERIPHERAL TISSUES AND DURING EMBRYONIC DEVELOPMENT

Glutaryl-CoA dehydrogenase (GCDH, EC 1.3.99.7) deficiency, known as glutaric acidemia type I, is one of the more common organic acidurias. To investigate the role of this pathway in different organs we studied the tissue-specific expression pattern of rat Gcdh. The open reading frame cDNA of the rat Gcdh gene was cloned from rat brain mRNA by RT-PCR, allowing the synthesis of digoxigenin-labeled in situ hybridization (ISH) riboprobes. Gcdh mRNA expression was analyzed by ISH on cryosections of adult rat brain, kidney, liver, spleen and heart muscle, as well as on E15 and E18 rat embryos. Gcdh was found expressed in the whole rat brain, almost exclusively in neurons. Gcdh was absent from astrocytes but expressed in rare oligodendrocytes. Strong Gcdh expression was found in liver and spleen, where expression appears predominant to lymphatic nodules. In kidney, the highest Gcdh expression is found in the juxtamedullar cortex (but not in glomerula), and at lower levels in medulla. Heart muscle was negative. During embryonic development, Gcdh was found well expressed in liver, intestinal mucosa and skin, as well as at lower levels in CNS. Further studies are ongoing to provide evidence on the presence of the entire pathway in CNS in order to understand the mechanisms leading to neurotoxicity in glutaric aciduria. The high expression of Gcdh in kidney may explain why certain patients with residual enzyme activity are low excretors at the urine metabolite level.

Differential regulation of the Hippo pathway by adherens junctions and apical-basal cell polarity modules.

Adherens junctions (AJs) and cell polarity complexes are key players in the establishment and maintenance of apical-basal cell polarity. Loss of AJs or basolateral polarity components promotes tumor formation and metastasis. Recent studies in vertebrate models show that loss of AJs or loss of the basolateral component Scribble (Scrib) cause deregulation of the Hippo tumor suppressor pathway and hyperactivation of its downstream effectors Yes-associated protein (YAP) and Transcriptional coactivator with PDZ-binding motif (TAZ). However, whether AJs and Scrib act through the same or independent mechanisms to regulate Hippo pathway activity is not known. Here, we dissect how disruption of AJs or loss of basolateral components affect the activity of the Drosophila YAP homolog Yorkie (Yki) during imaginal disc development. Surprisingly, disruption of AJs and loss of basolateral proteins produced very different effects on Yki activity. Yki activity was cell-autonomously decreased but non-cell-autonomously elevated in tissues where the AJ components E-cadherin (E-cad) or α-catenin (α-cat) were knocked down. In contrast, scrib knockdown caused a predominantly cell-autonomous activation of Yki. Moreover, disruption of AJs or basolateral proteins had different effects on cell polarity and tissue size. Simultaneous knockdown of α-cat and scrib induced both cell-autonomous and non-cell-autonomous Yki activity. In mammalian cells, knockdown of E-cad or α-cat caused nuclear accumulation and activation of YAP without overt effects on Scrib localization and vice versa. Therefore, our results indicate the existence of multiple, genetically separable inputs from AJs and cell polarity complexes into Yki/YAP regulation.

Differential association of drinking motives with alcohol use on weekdays and weekends.

Drinking motives (DM) reflect the reasons why individuals drink alcohol. Weekdays are mainly dedicated to work, whereas weekends are generally associated with spending time with friends during special events or leisure activities; using alcohol on weekdays and weekends may also be related to different DM. This study examined whether DM were differentially associated with drinking volume (DV) on weekdays and weekends. A representative sample of 5,391 young Swiss men completed a questionnaire assessing weekday and weekend DV, as well as their DM, namely, enhancement, social, coping, and conformity motives. Associations of DM with weekday and weekend DV were examined using structural equation models. Each DM was tested individually in a separate model; all associations were positive and generally stronger (except conformity) for weekend rather than for weekday DV. Further specific patterns of association were found when DM were entered into a single model simultaneously. Associations with weekday and with weekend DV were positive for enhancement and coping motives. However, associations were stronger with weekend rather than with weekday DV for enhancement, and stronger with weekday than with weekend DV for coping motives. Associations of social motives were not significant with weekend DV and negative with weekday DV. Conformity motives were negatively associated with weekend DV and positively related to weekday DV. These results suggest that interventions targeting enhancement motives should be particularly effective at decreasing weekend drinking, whereas interventions targeted at coping motives would be particularly effective at reducing alcohol use on weekdays. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Inhibition of glial cell proinflammatory activities by peroxisome proliferator-activated receptor gamma agonist confers partial protection during antimyelin oligodendrocyte glycoprotein demyelination in vitro.

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a member of the nuclear hormone superfamily originally characterized as a regulator of adipocyte differentiation and lipid metabolism. In addition, PPAR-gamma has important immunomodulatory functions. If the effect of PPAR-gamma's activation in T-cell-mediated demyelination has been recently demonstrated, nothing is known about the role of PPAR-gamma in antibody-induced demyelination in the absence of T-cell interactions and monocyte/macrophage activation. Therefore, we investigated PPAR-gamma's involvement by using an in vitro model of inflammatory demyelination in three-dimensional aggregating rat brain cell cultures. We found that PPAR-gamma was not constitutively expressed in these cultures but was strongly up-regulated following demyelination mediated by antibodies directed against myelin oligodendrocyte glycoprotein (MOG) in the presence of complement. Pioglitazone, a selective PPAR-gamma agonist, partially protected aggregates from anti-MOG demyelination. Heat shock responses and the expression of the proinflammatory cytokine tumor necrosis factor-alpha were diminished by pioglitazone treatment. Therefore, pioglitazone protection seems to be linked to an inhibition of glial cell proinflammatory activities following anti-MOG induced demyelination. We show that PPAR-gamma agonists act not only on T cells but also on antibody-mediated demyelination. This may represent a significant benefit in treating multiple sclerosis patients.

Renal protection with calcium antagonists: the role of lercanidipine.

Abstract Background: Clinical research in the field of hypertension is now increasingly focusing on the potential effects of antihypertensive treatments that may go beyond the reduction of blood pressure (BP). In particular, renal protection appears as a desirable goal, especially considering that hypertension is associated with an increased risk of developing kidney damage, which may eventually lead to end-stage renal disease and a higher mortality. Dihydropyridine calcium channel blockers (CCBs) are widely used in the field of hypertension therapy but the different renal effects of the various CCBs have been poorly explored to date. Scope: This review will discuss available evidence on the renal effects of two calcium channel blockers: amlodipine and lercanidipine, on the basis of clinical data. Methods: MEDLINE and EMBASE were searched for inclusion of relevant studies. No limitations in time were considered. Results: Results from preclinical and clinical studies suggest that amlodipine is overall less effective in terms of renal protection when compared with other antihypertensive tested agents. Its beneficial effect in retarding the progression of renal disease is achievable only when combined with a blocker of the renin-angiotensin system. Conversely lercanidipine seems to provide renal protection in a similar way to ACE inhibitors, probably thanks to its mechanism of action which acts directly on the afferent and efferent renal arterioles. Conclusions: Treatment of hypertension with CCBs should take into consideration the special effects of each single agent at different levels; lercanidipine for example may play a useful role in the management not only of hypertension but also in renal protection of hypertensive patients.

Differential roles of T cell receptor alpha and beta chains in ligand binding among H-2Kd-restricted cytolytic T lymphocyte clones specific for a photoreactive Plasmodium berghei circumsporozoite peptide derivative.

To study the interaction of T cell receptor with its ligand, a complex of a major histocompatibility complex molecule and a peptide, we derived H-2Kd-restricted cytolytic T lymphocyte clones from mice immunized with a Plasmodium berghei circumsporozoite peptide (PbCS) 252-260 (SYIPSAEKI) derivative containing photoreactive Nepsilon-[4-azidobenzoyl] lysine in place of Pro-255. This residue and Lys-259 were essential parts of the epitope recognized by these clones. Most of the clones expressed BV1S1A1 encoded beta chains along with specific complementary determining region (CDR) 3beta regions but diverse alpha chain sequences. Surprisingly, all T cell receptors were preferentially photoaffinity labeled on the alpha chain. For a representative T cell receptor, the photoaffinity labeled site was located in the Valpha C-strand. Computer modeling suggested the presence of a hydrophobic pocket, which is formed by parts of the Valpha/Jalpha C-, F-, and G-strands and adjacent CDR3alpha residues and structured to be able to avidly bind the photoreactive ligand side chain. We previously found that a T cell receptor specific for a PbCS peptide derivative containing this photoreactive side chain in position 259 similarly used a hydrophobic pocket located between the junctional CDR3 loops. We propose that this nonpolar domain in these locations allow T cell receptors to avidly and specifically bind epitopes containing non-peptidic side chains.

Predictors of HIV-protection behaviour in HIV-positive men who have sex with casual male partners: a test of the explanatory power of an extended Information-Motivation-Behavioural Skills model.

This prospective study applies an extended Information-Motivation-Behavioural Skills (IMB) model to establish predictors of HIV-protection behaviour among HIV-positive men who have sex with men (MSM) during sex with casual partners. Data have been collected from anonymous, self-administered questionnaires and analysed by using descriptive and backward elimination regression analyses. In a sample of 165 HIV-positive MSM, 82 participants between the ages of 23 and 78 (M=46.4, SD=9.0) had sex with casual partners during the three-month period under investigation. About 62% (n=51) have always used a condom when having sex with casual partners. From the original IMB model, only subjective norm predicted condom use. More important predictors that increased condom use were low consumption of psychotropics, high satisfaction with sexuality, numerous changes in sexual behaviour after diagnosis, low social support from friends, alcohol use before sex and habitualised condom use with casual partner(s). The explanatory power of the calculated regression model was 49% (p<0.001). The study reveals the importance of personal and social resources and of routines for condom use, and provides information for the research-based conceptualisation of prevention offers addressing especially people living with HIV ("positive prevention").