Fiscal Federalism at the Ballot Box : The Relevance of Expressive Voting

This paper explores the impact of citizens' motivation to vote on the pattern of fiscal federalism. If the only concern of instrumental citizens was outcome they would have little incentive to vote because the probability that a single vote might change an electoral outcome is usually minuscule. If voters turn out in large numbers to derive intrinsic value from action, how will these voters choose when considering the role local jurisdictions should play? The first section of the paper assesses the weight that expressive voters attach to an instrumental evaluation of alternative outcomes. Predictions are tested with reference to case study analysis of the way Swiss voters assessed the role their local jurisdiction should play. The relevance of this analysis is also assessed with reference to the choice that voters express when considering other local issues. Textbook analysis of fiscal federalism is premised on the assumption that voters register choice just as 'consumers' reveal demand for services in a market, but how robust is this analogy.

Manipulating keratinocyte stem cell proliferation and differentiation using RNA interference

ABSTRACT : The epidermis, the outermost compartment of the skin, is a stratified and squamous epithelium that constantly self-renews. Keratinocytes, which represent the main epidermal population, are responsible for its cohesion and barrier function. Epidermal renewal necessitates a fine equilibrium between keratinocyte proliferation and differentiation. The keratinocyte stem cell, located in the basal cell layer, is responsible for epidermal homeostasis and regeneration during the wound healing process. The transcription factor p63 structurally belongs to the p53 superfamily. It is expressed in the basal and supra-basal cell layers of stratified epithelia and is thought to be important for the renewal or the differentiation of keratinocyte stem cells (Yang et al., 1999; Mills et al., 1999). In order to better understand its function, we established an in vitro model of p63 deficient human keratinocyte stem cells using a shp63 mediated RNA interference. Knockdown of endogenous p63 induces downregulation of cell-adhesion genes as previously described (Carroll et al., 2006). Interestingly, the replating of attached p63-knockdown keratinocytes on a feeder layer results in a loss of attachment and proliferation. They are no longer clonogenic. However, if the same population are replated in a fibrin matrix, extended fibrinolysis is reported, a common process in wound healing, suggesting that p63 regulates the fibrinolytic pathway. This result was confirmed by Q-PCR and shows that the urokinase pathway, which mediates fibrinolysis, is upregulated. Altogether, these findings suggest a mechanism in which the fine tuning of p63 expression promotes attachment or release of the keratinocyte stem cell from the basement membrane by inducing genes of adhesion and/or of fibrinolysis. This mechanism may be important for epidermal self-renewal, differentiation as well as wound healing. Its misregulation may be partly responsible for the p63 knockout phenotype. The downregulation of p63 also induces a decrease in LEKTI expression. LEKTI (lymphoepithelial Kazal-type serine protease inhibitor) is a serine protease inhibitor encoded by the Spink5 gene. It is expressed and secreted in the uppermost differentiated layers of stratified epithelia and plays a role in the desquamation process. When this gene is disrupted, humans develop the Netherton syndrome (Chavanas et al., 2000b). It is a dermatosis characterized by hair dysplasias, ichtyosiform erythroderma and impairment in epidermal barrier function promoting inflammation similarly as in psoriasis with inflammatory infiltrate in excess. TNFα (tumor necrosis factor alpha) and EDA1 (ectodysplasin A1) are two transmembraneprecursors that belong to the TNF superfamily, which is involved in immune and inflammation regulation (Smahi et al., 2002). We suggest that the secreted serine protease inhibitor LEKTI plays a role in the regulation of TNFα and EDA1 precursor cleavage and absence of LEKTI induces excess of inflammation. To investigate this hypothesis, we induced downregulation of Spink5 expression in rat keratinocyte stem cells by using a shSpink5 mediated RNA interference approach. Interestingly, expression of TNFα and EDA1 is modified after knockdown of Spink5 by Q-PCR. Moreover, downregulation of Spink5 induces loss of cohesiveness between keratinocytes and colonies adopt a scattered phenotype. Altogether, these preliminary data suggest that downregulation of LEKTI may play a role in the inflammatory response in Netherton syndrome patients, by regulating TNFα expression.

The pollutant diethylhexyl phthalate regulates hepatic energy metabolism via species-specific PPARalpha-dependent mechanisms.

Background: The modulation of energetic homeostasis by pollutants has recently emerged as a potential contributor to the onset of metabolic disorders. Diethylhexyl phthalate (DEHP) is a widely used industrial plasticizer to which humans are widely exposed. Phthalates can activate the three peroxisome proliferatoractivated receptor (PPAR) isotypes on cellular models and induce peroxisome proliferation in rodents.Objectives: In this study, we aimed to evaluate the systemic and metabolic consequences of DEHP exposure that have remained so far unexplored and to characterize the underlying molecular mechanisms of action.Methods: As a proof of concept and mechanism, genetically engineered mouse models of PPARs were exposed to high doses of DEHP, followed by metabolic and molecular analyses.Results: DEHP-treated mice were protected from diet-induced obesity via PPARalpha-dependent activation of hepatic fatty acid catabolism, whereas the activity of neither PPARbeta nor PPARgamma was affected. However, the lean phenotype observed in response to DEHP in wild-type mice was surprisingly abolished in PPARalpha-humanized mice. These species differences are associated with a different pattern of coregulator recruitment.Conclusion: These results demonstrate that DEHP exerts species-specific metabolic actions that rely to a large extent on PPARalpha signaling and highlight the metabolic importance of the species-specific activation of PPARalpha by xenobiotic compounds. Editor's SummaryDiethylhexyl phthalate (DEHP) is an industrial plasticizer used in cosmetics, medical devices, food packaging, and other applications. Evidence that DEHP metabolites can activate peroxisome proliferatoractivated receptors (PPARs) involved in fatty acid oxidation (PPARalpha and PPARbeta) and adiposite function and insulin resistance (PPARgamma) has raised concerns about potential effects of DEHP on metabolic homeostasis. In rodents, PPARalpha activation also induces hepatic peroxisome proliferation, but this response to PPARalpha activation is not observed in humans. Feige et al. (p. 234) evaluated systemic and metabolic consequences of high-dose oral DEHP in combination with a high-fat diet in wild-type mice and genetically engineered mouse PPAR models. The authors report that mice exposed to DEHP gained less weight than controls, without modifying their feeding behavior; they also exhibited lower triglyceride levels, smaller adipocytes, and improved glucose tolerance compared with controls. These effects, which were observed in mice fed both high-fat and standard diets, appeared to be mediated by PPARalpha-dependent activation of hepatic fatty acid catabolism without apparent involvement of PPARbeta or PPARgamma. However, mouse models that expressed human (versus mouse) PPARalpha tended to gain more weight on a high-fat diet than their DHEP-unexposed counterparts. The authors conclude that findings support species-specific metabolic effects of DEHP mediated by PPARalpha activation.

On estimation and identifiability issues of sex-linked inheritance with a case study of pigmentation in Swiss barn owl (Tyto alba)

Genetic evaluation using animal models or pedigree-based models generally assume only autosomal inheritance. Bayesian animal models provide a flexible framework for genetic evaluation, and we show how the model readily can accommodate situations where the trait of interest is influenced by both autosomal and sex-linked inheritance. This allows for simultaneous calculation of autosomal and sex-chromosomal additive genetic effects. Inferences were performed using integrated nested Laplace approximations (INLA), a nonsampling-based Bayesian inference methodology. We provide a detailed description of how to calculate the inverse of the X- or Z-chromosomal additive genetic relationship matrix, needed for inference. The case study of eumelanic spot diameter in a Swiss barn owl (Tyto alba) population shows that this trait is substantially influenced by variation in genes on the Z-chromosome (sigma(2)(z) = 0.2719 and sigma(2)(a) = 0.4405). Further, a simulation study for this study system shows that the animal model accounting for both autosomal and sex-chromosome-linked inheritance is identifiable, that is, the two effects can be distinguished, and provides accurate inference on the variance components.

Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project.

We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.

Keratin degradation by dermatophytes relies on cysteine dioxygenase and a sulfite efflux pump.

Millions of people suffer from superficial infections caused by dermatophytes. Intriguingly, these filamentous fungi exclusively infect keratin-rich host structures such as hair, nails, and skin. Keratin is a hard, compact protein, and its utilization by dermatophytes for growth has long been discussed as a major virulence attribute. Here, we provide strong support for the hypothesis that keratin degradation is facilitated by the secretion of the reducing agent sulfite, which can cleave keratin-stabilizing cystine bonds. We discovered that sulfite is produced by dermatophytes from environmental cysteine, which at elevated concentrations is toxic for microbes and humans. We found that sulfite formation from cysteine relies on the key enzyme cysteine dioxygenase Cdo1. Sulfite secretion is supported by the sulfite efflux pump Ssu1. Targeted mutagenesis proved that dermatophyte mutants in either Cdo1 or Ssu1 were highly growth-sensitive to cysteine, and mutants in Ssu1 were specifically sensitive to sulfite. Most notably, dermatophyte mutants in Cdo1 and Ssu1 were specifically growth-defective on hair and nails. As keratin is rich in cysteine, our identified mechanism of cysteine conversion and sulfite efflux supports both cysteine and sulfite tolerance per se and progression of keratin degradation. These in vitro findings have implications for dermatophyte infection pathogenesis.

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.

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention.

Endothelial nitric oxide synthase gene transfer restores endothelium-dependent relaxations and attenuates lesion formation in carotid arteries in apolipoprotein E-deficient mice.

Nitric oxide (NO) and monocyte chemoattractant protein-1 (MCP-1) exert partly opposing effects in vascular biology. NO plays pleiotropic vasoprotective roles including vasodilation and inhibition of platelet aggregation, smooth muscle cell proliferation, and endothelial monocyte adhesion, the last effect being mediated by MCP-1 downregulation. Early stages of arteriosclerosis are associated with reduced NO bioactivity and enhanced MCP-1 expression. We have evaluated adenovirus-mediated gene transfer of human endothelial NO synthase (eNOS) and of a N-terminal deletion (8ND) mutant of the MCP-1 gene that acts as a MCP-1 inhibitor in arteriosclerosis-prone, apolipoprotein E-deficient (ApoE(-/-)) mice. Endothelium-dependent relaxations were impaired in carotid arteries instilled with a noncoding adenoviral vector but were restored by eNOS gene transfer (p < 0.01). A perivascular collar was placed around the common carotid artery to accelerate lesion formation. eNOS gene transfer reduced lesion surface areas, intima/media ratios, and macrophage contents in the media at 5-week follow-up (p < 0.05). In contrast, 8ND-MCP-1 gene transfer did not prevent lesion formation. In conclusion, eNOS gene transfer restores endothelium-dependent vasodilation and inhibits lesion formation in ApoE(-/-) mouse carotids. Further studies are needed to assess whether vasoprotection is maintained at later disease stages and to evaluate the long-term efficacy of eNOS gene therapy for primary arteriosclerosis.

The stabilizing effects of the acquired immunity on the schistosomiasis transmission modeling - the sensitivity Analysis

A mathematical model is proposed to analyze the effects of acquired immunity on the transmission of schistosomiasis in the human host. From this model the prevalence curve dependent on four parameters can be obtained. These parameters were estimated fitting the data by the maximum likelihood method. The model showed a good retrieving capacity of real data from two endemic areas of schistosomiasis: Touros, Brazil (Schistosoma mansoni) and Misungwi, Tanzania (S. haematobium). Also, the average worm burden per person and the dispersion of parasite per person in the community can be obtained from the model. In this paper, the stabilizing effects of the acquired immunity assumption in the model are assessed in terms of the epidemiological variables as follows. Regarded to the prevalence curve, we calculate the confidence interval, and related to the average worm burden and the worm dispersion in the community, the sensitivity analysis (the range of the variation) of both variables with respect to their parameters is performed.

Renal tubular NEDD4-2 deficiency causes NCC-mediated salt-dependent hypertension.

The E3 ubiquitin ligase NEDD4-2 (encoded by the Nedd4L gene) regulates the amiloride-sensitive epithelial Na+ channel (ENaC/SCNN1) to mediate Na+ homeostasis. Mutations in the human β/γENaC subunits that block NEDD4-2 binding or constitutive ablation of exons 6-8 of Nedd4L in mice both result in salt-sensitive hypertension and elevated ENaC activity (Liddle syndrome). To determine the role of renal tubular NEDD4-2 in adult mice, we generated tetracycline-inducible, nephron-specific Nedd4L KO mice. Under standard and high-Na+ diets, conditional KO mice displayed decreased plasma aldosterone but normal Na+/K+ balance. Under a high-Na+ diet, KO mice exhibited hypercalciuria and increased blood pressure, which were reversed by thiazide treatment. Protein expression of βENaC, γENaC, the renal outer medullary K+ channel (ROMK), and total and phosphorylated thiazide-sensitive Na+Cl- cotransporter (NCC) levels were increased in KO kidneys. Unexpectedly, Scnn1a mRNA, which encodes the αENaC subunit, was reduced and proteolytic cleavage of αENaC decreased. Taken together, these results demonstrate that loss of NEDD4-2 in adult renal tubules causes a new form of mild, salt-sensitive hypertension without hyperkalemia that is characterized by upregulation of NCC, elevation of β/γENaC, but not αENaC, and a normal Na+/K+ balance maintained by downregulation of ENaC activity and upregulation of ROMK.

Phosphate import at the arbuscule: just a nutrient?

Central to the mutualistic arbuscular mycorrhizal symbiosis is the arbuscule, the site where symbiotic phosphate is delivered. Initial investigations in legumes have led to the exciting observation that symbiotic phosphate uptake not only enhances plant growth but also regulates arbuscule dynamics and is, furthermore, required for maintenance of the symbiosis. This review evaluates the possible role of the phosphate ion, not only as a nutrient but also as a signal that is necessary for reprogramming the host cortex cell for symbiosis.

RasGAP-derived fragment N increases the resistance of beta cells towards apoptosis in NOD mice and delays the progression from mild to overt diabetes.

The caspase-3-generated RasGAP N-terminal fragment (fragment N) inhibits apoptosis in a Ras-PI3K-Akt-dependent manner. Fragment N protects various cell types, including insulin-secreting cells, against different types of stresses. Whether fragment N exerts a protective role during the development of type 1 diabetes is however not known. Non-obese diabetic (NOD) mice represent a well-known model for spontaneous development of type 1 diabetes that shares similarities with the diseases encountered in humans. To assess the role of fragment N in type 1 diabetes development, a transgene encoding fragment N under the control of the rat insulin promoter (RIP) was back-crossed into the NOD background creating the NOD-RIPN strain. Despite a mosaic expression of fragment N in the beta cell population of NOD-RIPN mice, islets isolated from these mice were more resistant to apoptosis than control NOD islets. Islet lymphocytic infiltration and occurrence of a mild increase in glycemia developed with the same kinetics in both strains. However, the period of time separating the mild increase in glycemia and overt diabetes was significantly longer in NOD-RIPN mice compared to the control NOD mice. There was also a significant decrease in the number of apoptotic beta cells in situ at 16 weeks of age in the NOD-RIPN mice. Fragment N exerts therefore a protective effect on beta cells within the pro-diabetogenic NOD background and this prevents a fast progression from mild to overt diabetes.

Are oxygen uptake kinetics modified when using a respiratory snorkel?

PURPOSE: The aim of this study was to compare VO2 kinetics during constant power cycle exercise measured using a conventional facemask (CM) or a respiratory snorkel (RS) designed for breath-by-breath analysis in swimming. METHODS: VO2 kinetics parameters-obtained using CM or RS, in randomized counterbalanced order-were compared in 10 trained triathletes performing two submaximal heavy-intensity cycling square-wave transitions. These VO2 kinetics parameters (ie, time delay: td1, td2; time constant: τ1, τ2; amplitude: A1, A2, for the primary phase and slow component, respectively) were modeled using a double exponential function. In the case of the RS data, this model incorporated an individually determined snorkel delay (ISD). RESULTS: Only td1 (8.9 ± 3.0 vs 13.8 ± 1.8 s, P < .01) differed between CM and RS, whereas all other parameters were not different (τ1 = 24.7 ± 7.6 vs 21.1 ± 6.3 s; A1 = 39.4 ± 5.3 vs 36.8 ± 5.1 mL x min(-1) x kg(-1); td2 = 107.5 ± 87.4 vs 183.5 ± 75.9 s; A2' (relevant slow component amplitude) = 2.6 ± 2.4 vs 3.1 ± 2.6 mL x min(-1) x kg(-1) for CM and RS, respectively). CONCLUSIONS: Although there can be a small mixture of breaths allowed by the volume of the snorkel in the transition to exercise, this does not appear to significantly influence the results. Therefore, given the use of an ISD, the RS is a valid instrument for the determination of VO2 kinetics within submaximal exercise.