GABAA receptor dependent synaptic inhibition rapidly tunes KCC2 activity via the Cl--sensitive WNK1 kinase

This is the final version of the article. Available from the publisher via the DOI in this record.There is another ORE record for this publication: http://hdl.handle.net/10871/33406The K+-Cl-co-transporter KCC2 (SLC12A5) tunes the efficacy of GABAAreceptor-mediated transmission by regulating the intraneuronal chloride concentration [Cl-]i. KCC2 undergoes activity-dependent regulation in both physiological and pathological conditions. The regulation of KCC2 by synaptic excitation is well documented; however, whether the transporter is regulated by synaptic inhibition is unknown. Here we report a mechanism of KCC2 regulation by GABAAreceptor (GABAAR)-mediated transmission in mature hippocampal neurons. Enhancing GABAAR-mediated inhibition confines KCC2 to the plasma membrane, while antagonizing inhibition reduces KCC2 surface expression by increasing the lateral diffusion and endocytosis of the transporter. This mechanism utilizes Cl-as an intracellular secondary messenger and is dependent on phosphorylation of KCC2 at threonines 906 and 1007 by the Cl--sensing kinase WNK1. We propose this mechanism contributes to the homeostasis of synaptic inhibition by rapidly adjusting neuronal [Cl-]ito GABAAR activity.This work was supported in part by Inserm, Sorbonne Université-UPMC, as well as the Fondation pour la Recherche Médicale (Equipe FRM DEQ20140329539 to J.C.P.), the Human Frontier Science Program (RGP0022/2013 to J.C.P.) and the Fondation pour la Recherche sur le Cerveau (to S.L.). Equipment at the IFM was also supported by DIM NeRF from Région Ile-de-France and by the FRC/Rotary ‘Espoir en tête’. M.H. was the recipient of a doctoral fellowship from the Université Pierre and Marie Curie, as well as from Bio-Psy Laboratory of excellence. K.T.K. is supported by the National Institutes of Health, the Simons Foundation, and the March of Dimes Foundation Basil O’Connor Award. The Poncer/Lévi lab is affiliated with the Paris School of Neuroscience (ENP) and the Bio-Psy Laboratory of excellence

Molecular phylogenetic analysis of Arenaria (Caryophyllaceae: tribe Arenarieae) and its allies inferred from nuclear DNA internal transcribed spacer and plastid DNA rps16 sequences

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112194/1/boj12293.pd

Untangling phylogenetic patterns and taxonomic confusion in tribe Caryophylleae (Caryophyllaceae) with special focus on generic boundaries

Assigning correct names to taxa is a challenging goal in the taxonomy of many groups within the Caryophyllaceae. This challenge is most serious in tribe Caryophylleae since the supposed genera seem to be highly artificial, and the available morphological evidence cannot effectively be used for delimitation and exact determination of taxa. The main goal of the present study was to re–assess the monophyly of the genera currently recognized in this tribe using molecular phylogenetic data. We used the sequences of nuclear ribosomal internal transcribed spacer (ITS) and the chloroplast gene rps16 for 135 and 94 accessions, respectively, representing all 16 genera currently recognized in the tribe Caryophylleae, with a rich sampling of Gypsophila as one of the most heterogeneous groups in the tribe. Phylogenetic trees were reconstructed using maximum parsimony and Bayesian inference methods. The results show that most of the large genera of Caryophylleae are not monophyletic. As a result, we propose a new classification system matching both molecular phylogenetic and morphological evidence. The main taxonomic conclusions include: (1) the description of three new genera, (2) treating five small genera as synonyms, (3) resurrecting the genus Heterochroa with six species, and (4) proposing 23 new combinations plus 2 replacement names at the specific level. As a result, we recognize 14 genera in Caryophylleae. A diagnostic key to all genera of Caryophylleae is provided.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146908/1/tax6716.pd

Unravelling the phylogeny of the root-hemiparasitic genus Odontites (tribe Rhinantheae, Orobanchaceae): Evidence for five main lineages

[EN] Despite the recent publication of several phylogenies focused on Rhinantheae, which has been expanded to include three Asian endemic genera, few studies so far have dealt with particular genera within the tribe. Here, we focus on Odontites and related genera because of the high morphological variability of the group and its unclear generic boundaries. Phylogenetic analyses were performed for nrDNA (ITS) and cpDNA (trnK region and rps16 intron) datasets, using Bayesian and Parsimony analyses. Our results cast doubt on the inclusion of Pterygiella and related genera within the Rhinantheae and support the paraphyly of Phtheirospermum, making it necessary to propose three new combinations to avoid it. Odontites is recircumscribed to include Bartsiella, Bornmuellerantha, and Macrosyringion, but not Odontitella. Within Odontites, five distinct lineages are identified. These are distinguishable either by morphological synapomorphies or by a combination of several character states. Most of the Odontites species are regarded as monophyletic. In the O. vernus and O. luteus complexes, some taxonomic changes are made to avoid paraphyly, which results in three new combinations

Towards resolving Lamiales relationships: insights from rapidly evolving chloroplast sequences

<p>Abstract</p> <p>Background</p> <p>In the large angiosperm order Lamiales, a diverse array of highly specialized life strategies such as carnivory, parasitism, epiphytism, and desiccation tolerance occur, and some lineages possess drastically accelerated DNA substitutional rates or miniaturized genomes. However, understanding the evolution of these phenomena in the order, and clarifying borders of and relationships among lamialean families, has been hindered by largely unresolved trees in the past.</p> <p>Results</p> <p>Our analysis of the rapidly evolving <it>trnK/matK</it>, <it>trnL-F </it>and <it>rps16 </it>chloroplast regions enabled us to infer more precise phylogenetic hypotheses for the Lamiales. Relationships among the nine first-branching families in the Lamiales tree are now resolved with very strong support. Subsequent to Plocospermataceae, a clade consisting of Carlemanniaceae plus Oleaceae branches, followed by Tetrachondraceae and a newly inferred clade composed of Gesneriaceae plus Calceolariaceae, which is also supported by morphological characters. Plantaginaceae (incl. Gratioleae) and Scrophulariaceae are well separated in the backbone grade; Lamiaceae and Verbenaceae appear in distant clades, while the recently described Linderniaceae are confirmed to be monophyletic and in an isolated position.</p> <p>Conclusions</p> <p>Confidence about deep nodes of the Lamiales tree is an important step towards understanding the evolutionary diversification of a major clade of flowering plants. The degree of resolution obtained here now provides a first opportunity to discuss the evolution of morphological and biochemical traits in Lamiales. The multiple independent evolution of the carnivorous syndrome, once in Lentibulariaceae and a second time in Byblidaceae, is strongly supported by all analyses and topological tests. The evolution of selected morphological characters such as flower symmetry is discussed. The addition of further sequence data from introns and spacers holds promise to eventually obtain a fully resolved plastid tree of Lamiales.</p

Reciprocal Regulation of KCC2 Trafficking and Synaptic Activity

The main inhibitory neurotransmitter receptors in the adult central nervous system (CNS) are type A γ-aminobutyric acid receptors (GABAARs) and glycine receptors (GlyRs). Synaptic responses mediated by GlyR and GABAAR display a hyperpolarizing shift during development. This shift relies mainly on the developmental up-regulation of the K+-Cl− co-transporter KCC2 responsible for the extrusion of Cl−. In mature neurons, altered KCC2 function—mainly through increased endocytosis—leads to the re-emergence of depolarizing GABAergic and glycinergic signaling, which promotes hyperexcitability and pathological activities. Identifying signaling pathways and molecular partners that control KCC2 surface stability thus represents a key step in the development of novel therapeutic strategies. Here, we present our current knowledge on the cellular and molecular mechanisms governing the plasma membrane turnover rate of the transporter under resting conditions and in response to synaptic activity. We also discuss the notion that KCC2 lateral diffusion is one of the first parameters modulating the transporter membrane stability, allowing for rapid adaptation of Cl− transport to changes in neuronal activity

Energetics and the evolution of carnivorous plants - Darwin's "most wonderful plants in the world"

Carnivory has evolved independently at least six times in five angiosperm orders. In spite of these independent origins, there is a remarkable morphological convergence of carnivorous plant traps and physiological convergence of mechanisms for digesting and assimilating prey. These convergent traits have made carnivorous plants model systems for addressing questions in plant molecular genetics, physiology, and evolutionary ecology. New data show that carnivorous plant genera with morphologically complex traps have higher relative rates of gene substitutions than do those with simple sticky traps. This observation suggests two alternative mechanisms for the evolution and diversification of carnivorous plant lineages. The “energetics hypothesis” posits rapid morphological evolution resulting from a few changes in regulatory genes responsible for meeting the high energetic demands of active traps. The “predictable prey capture hypothesis” further posits that complex traps yield more predictable and frequent prey captures. To evaluate these hypotheses, available data on the tempo and mode of carnivorous plant evolution were reviewed; patterns of prey capture by carnivorous plants were analyzed; and the energetic costs and benefits of botanical carnivory were reevaluated. Collectively, the data are more supportive of the energetics hypothesis than the predictable prey capture hypothesis. The energetics hypothesis is consistent with a phenomenological cost-benefit model for the evolution of botanical carnivory and also accounts for data suggesting that carnivorous plants have leaf construction costs and scaling relationships among leaf traits that are substantially different from non-carnivorous plants.Organismic and Evolutionary BiologyOther Research Uni

Superando problemas de extracción de ADN de plantas carnívoras

We tested previously published protocols for DNA isolation from plants with high contents of polyphenols and polysaccharides for several taxa of carnivorous plants. However, we did not get satisfying results with fresh or silica dried leaf tissue obtained from field collected or greenhouse grown plants, nor from herbarium specimens. Therefore, we have developed a simple modified protocol of the commercially available Macherey- Nagel NucleoSpin® Plant kit for rapid, effective and reproducible isolation of high quality genomic DNA suitable for PCR reactions. DNA extraction can be conducted from both fresh and dried leaf tissue of various carnivorous plant taxa, irrespective of high contents of polysaccharides, phenolic compounds and other secondary plant metabolites that interfere with DNA isolation and amplification.Probamos algunos protocolos publicados previamente para el aislamiento del ADN de plantas con alto contenido de polifenoles y polisacáridos para varios táxones de plantas carnívoras. Sin embargo, no conseguimos muy buenos resultados ni con tejidos de hojas frescas, ni con tejidos de hojas secadas en gel de sílice obtenidas de plantas colectadas en el campo o cultivadas en los invernaderos, ni de especímenes de herbario. Por lo tanto, hemos desarrollado un protocolo sencillo, modificado del Macherey- Nagel NucleoSpin® Plant kit disponible en el mercado para el aislamiento rápido, eficaz y reproducible de ADN genómico de alta calidad conveniente para la reacción en cadena de la polimerasa. La extracción del ADN se puede realizar en tejidos de hojas frescas o secas de varios táxones de plantas carnívoras, sin importar el grado de contenido de polisacáridos, compuestos fenólicos u otros metabolitos secundarios que interfieren con el aislamiento y la amplificación del ADN

Traditionelle chinesische Arzneitherapie bei Patienten mit chronischer Rhinosinusitis - eine Therapiebeobachtung mit Berücksichtigung der Arzneimittelherkunft

BACKGROUND The use of Chinese medicinal drugs is becoming more common in Germany. However, the import from China results in aggravated quality controls and potentially jeopardized therapeutic safety. Therefore, in 1999 the Bavarian Department for Agriculture has initiated an interdisciplinary research project to cultivate and analyze important Chinese herbal plants. Currently 16 Bavarian-produced Chinese drugs are in use and distributed to patients by pharmacies. Despite a comparable quality of Bavarian pharmaceutical products, there are concerns remaining as the Bavarian medical drugs have been used for treatment purposes on patients since 2006, without their effect having been compared to the Chinese products. Therefore we performed an observational trial using a parallel group design on patients with chronic rhinosinusitis. METHODS The duration of the trial was 4 weeks. After a 4-week follow-up, the patients were interviewed via telephone. During the trial the patients were given 2 × 50 ml of a decoction of Chinese medicinal herbs, either (a) from Bavarian controlled cultivation (Bavaria group) or (b) from Chinese production (China group). The therapeutic success was evaluated using numerical rating scales. RESULTS In total, 64 patients completed the observational trial (31 Bavaria group, 33 China group). Both groups showed significant improvements in the main symptom scores of chronic rhinosinusitis as well as in secondary symptoms, such as the overall state of health or the tendency to catch a cold. There were no significant differences between the groups concerning the main symptoms scores. Overall the herbal decoctions had no severe side effects. CONCLUSION This observational trial shows that Chinese herbal drugs from Bavarian cultivation are as effective as medicinal herbs imported from China, but the effects of concomitant therapies must be considered as well. The symptom score improvements during the treatment period were obvious and should stimulate further investigation on the efficacy of this herbal formula in the treatment of chronic rhinosinusitis

Functional characterization of a class III acid endochitinase from the traps of the carnivorous pitcher plant genus, Nepenthes

Carnivory in plants is an adaptation strategy to nutrient-poor environments and soils. Carnivorous plants obtain some additional mineral nutrients by trapping and digesting prey; the genus Nepenthes is helped by its specialized pitcher traps. To make the nutrients available, the caught prey needs to be digested, a process that requires the concerted activity of several hydrolytic enzymes. To identify and investigate the various enzymes involved in this process, fluid from Nepenthes traps has been analysed in detail. In this study, a novel type of Nepenthes endochitinase was identified in the digestion fluid of closed pitchers. The encoding endochitinase genes have been cloned from eight different Nepenthes species. Among these, the deduced amino acid sequence similarity was at least 94.9%. The corresponding cDNA from N. rafflesiana was heterologously expressed, and the purified protein, NrChit1, was biochemically characterized. The enzyme, classified as a class III acid endochitinase belonging to family 18 of the glycoside hydrolases, is secreted into the pitcher fluid very probably due to the presence of an N-terminal signal peptide. Transcriptome analyses using real-time PCR indicated that the presence of prey in the pitcher up-regulates the endochitinase gene not only in the glands, which are responsible for enzyme secretion, but at an even higher level, in the glands’ surrounding tissue. These results suggest that in the pitchers’ tissues, the endochitinase as well as other proteins from the pitcher fluid might fulfil a different, primary function as pathogenesis-related proteins