Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
establishing embryonic territories in the context of wnt signaling.this review highlights the work that my research group has been developing, together with international collaborators, during the last decade. since we were able to establish xenopus laevis experimental model in brazil we have been focused on understanding early embryonic patterns regarding neural induction and axes establishment. in this context, wnt pathway appears as a major player and has been much explored by us and other research groups. here we chose to review three published works that w ...202032930371
a collision coupling model governs the activation of neuronal girk1/2 channels by muscarinic-2 receptors.the g protein-activated inwardly rectifying k+-channel (girk) modulates heart rate and neuronal excitability. following g-protein coupled receptor (gpcr)-mediated activation of heterotrimeric g proteins (gαβγ), opening of the channel is obtained by direct binding of gβγ subunits. interestingly, girks are solely activated by gβγ subunits released from gαi/o-coupled gpcrs, despite the fact that all receptor types, for instance gαq-coupled, are also able to provide gβγ subunits. it is proposed that ...202032903404
lethal and teratogenic impacts of imazapyr, diquat dibromide, and glufosinate ammonium herbicide formulations using frog embryo teratogenesis assay-xenopus (fetax).globally, amphibians are experiencing widespread abnormalities and population declines. one potential contributor to these challenges is the use of pesticides, particularly aquatic herbicides applied to aquatic habitats inhabited by amphibians. critical issues of concern are the potential toxicity and teratogenicity of these herbicides towards amphibians. using the fetax protocol, three globally used formulations, including diquat dibromide (midstream), glufosinate ammonium (basta), and imazapyr ...202032901337
maximizing crispr/cas9 phenotype penetrance applying predictive modeling of editing outcomes in xenopus and zebrafish embryos.crispr/cas9 genome editing has revolutionized functional genomics in vertebrates. however, crispr/cas9 edited f0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (dsb) repair. even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. recently, studies in cell culture systems have shown that the nature of cris ...202032887910
tetrapeptide ac-haee-nh2 protects α4β2 nachr from inhibition by aβ.the cholinergic deficit in alzheimer's disease (ad) may arise from selective loss of cholinergic neurons caused by the binding of aβ peptide to nicotinic acetylcholine receptors (nachrs). thus, compounds preventing such an interaction are needed to address the cholinergic dysfunction. recent findings suggest that the 11evhh14 site in aβ peptide mediates its interaction with α4β2 nachr. this site contains several charged amino acid residues, hence we hypothesized that the formation of aβ-α4β2 nac ...202032872553
effects of copper on the neuromasts of xenopus laevis.fish and aquatic amphibians possess neuromasts on the surface of their body that constitute the lateral line, a sensory system used to detect water displacement. copper is known to inactivate the neuromast organs of this system. copper-induced neuromast loss in african clawed frogs, xenopus laevis, was examined by exposing nieuwkoop-faber stage 54-55 larvae to copper concentrations of 0, 100, 200, 300, and 400 µg/l for 96 h, followed by an examination of neuromast counts, staining intensity, and ...202033180147
ecotoxicological assessment of commercial boron nitride nanotubes toward xenopus laevis tadpoles and host-associated gut microbiota.despite the growing interest for boron nitride nanotubes (bnnt) due to their unique properties, data on the evaluation of the environmental risk potential of this emerging engineered nanomaterial are currently lacking. therefore, the ecotoxicity of a commercial form of bnnt (containing tubes, hexagonal-boron nitride, and boron) was assessed in vivo toward larvae of the amphibian xenopus laevis. following the exposure, multiple endpoints were measured in the tadpoles as well as in bacterial commu ...202033171057
mechanisms activating latent functions of pip aquaporin water channels via the interaction between pip1 and pip2 proteins.plant plasma-membrane type pip aquaporins are classified into two groups, pip1s and pip2s. in this study, we focused on hvpip1; 2, a pip1 in barley (hordeum vulgare), to dissect the molecular mechanisms that evoke hvpip1-mediated water transport. no hvpip1; 2 protein was localized to the plasma membrane when expressed alone in xenopus laevis oocytes. in contrast, a chimeric hvpip1; 2 protein (hvpip1; 2_24nc), in which the n- and c-terminal regions were replaced with the corresponding regions fro ...202033169164
epigenetic regulation of replication origin assembly: a role for histone h1 and chromatin remodeling factors.during early embryonic development in several metazoans, accurate dna replication is ensured by high number of replication origins. this guarantees rapid genome duplication coordinated with fast cell divisions. in xenopus laevis embryos this program switches to one with a lower number of origins at a developmental stage known as mid-blastula transition (mbt) when cell cycle length increases and gene transcription starts. consistent with this regulation, somatic nuclei replicate poorly when trans ...202033165968
synthesis of glun2a-selective nmda receptor antagonists with an electron-rich aromatic b-ring.glutamatergic n-methyl-d-aspartate (nmda) receptors are heterotetrameric ion channels that can be comprised of different subunits. glun2a subunit-containing nmda receptors are associated with diseases like anxiety, depression, and schizophrenia. however, the exact contribution of these nmda receptor subtypes is still unclear. to understand better the role of the glun2a-containing receptors, novel ligands were designed. in co-crystallization with the isolated binding site, tcn-201 (1) and analogs ...202033162207
trim-away mediated knock down uncovers a new function for lbh during gastrulation of xenopus laevis.we previously identified the protein lbh as necessary for cranial neural crest (cnc) cell migration in xenopus through the use of morpholinos. however, lbh is a maternally deposited protein and morpholinos achieve knockdowns through prevention of translation. in order to investigate the role of lbh in earlier embryonic events, we employed the new technique "trim-away" to degrade this maternally deposited protein. trim-away utilizes the e3 ubiquitin ligase trim21 to degrade proteins targeted with ...202033159936
kunitz-type peptides from the sea anemone heteractis crispa demonstrate potassium channel blocking and anti-inflammatory activities.the kunitz/bpti peptide family includes unique representatives demonstrating various biological activities. electrophysiological screening of peptides hcrg1 and hcrg2 from the sea anemone heteractis crispa on six kv1.x channel isoforms and insect shaker ir channel expressed in xenopus laevis oocytes revealed their potassium channels blocking activity. hcrg1 and hcrg2 appear to be the first kunitz-type peptides from sea anemones blocking kv1.3 with ic50 of 40.7 and 29.7 nm, respectively. in addit ...202033158163
development of antimicrobial peptides from amphibians.since the discovery of magainins from the skin secretions of the african toad xenopus laevis by michael zasloff in 1987, an increasing number of antimicrobial peptides (amps) has been identified in different anuran species and studied in detail [...].202033158031
antimicrobial peptide induced-stress renders staphylococcus aureus susceptible to toxic nucleoside analogs.cationic antimicrobial peptides (amps) are active immune effectors of multicellular organisms and are also considered as new antimicrobial drug candidates. one of the problems encountered when developing amps as drugs is the difficulty of reaching sufficient killing concentrations under physiological conditions. here, using pexiganan, a cationic peptide derived from a host defense peptide of the african clawed frog and the first amp developed into an antibacterial drug, we studied whether sub-le ...202033133056
nicotinic acetylcholine receptors in the synganglion of the tick ixodes ricinus: functional characterization using membrane microtransplantation.nicotinic acetylcholine receptors are an important class of excitatory receptors in the central nervous system of arthropods. in the ticks ixodes ricinus, the functional and pharmacological properties of nicotinic receptors located in their neurons are still unknown. the objective of this study was to characterize the pharmacological properties of tick nicotinic receptors using membrane microtransplantation in xenopus laevis oocytes and two-electrodes voltage clamp method. the membranes microtra ...202033120248
observation of nucleic acids inside living human cells by in-cell nmr spectroscopy.the intracellular environment is highly crowded with biomacromolecules such as proteins and nucleic acids. under such conditions, the structural and biophysical features of nucleic acids have been thought to be different from those in vitro. to obtain high-resolution structural information on nucleic acids in living cells, the in-cell nmr method is a unique tool. following the first in-cell nmr measurement of nucleic acids in 2009, several interesting insights were obtained using xenopus laevis ...202033110737
high affinity na+ transport by wheat hkt1;5 is blocked by k.the wheat sodium transporters tmhkt1;5-a and tahkt1;5-d are encoded by genes underlying the major shoot na+ exclusion loci nax2 and kna1 from triticum monococcum (tm) and triticum aestivum (ta), respectively. in contrast to hkt2 transporters that have been shown to exhibit high affinity k+-dependent na+ transport, hkt1 proteins have, with one exception, only been shown to catalyze low affinity na+ transport and no k+ transport. here, using heterologous expression in xenopus laevis oocytes we unc ...202033103046
x-box-binding protein 1 is required for pancreatic development in xenopus laevis.x-box-binding protein 1 (xbp1) is a protein containing the basic leucine zipper structure. it belongs to the camp-response element binding protein (creb)/activating transcription factor transcription factor family. as the main transcription factor, spliced xbp1 (xbp1s) participates in many physiological and pathological processes and plays an important role in embryonic development. previous studies showed that xbp1-knockout mice died because of pancreatic exocrine function deficiency, indicatin ...202033098302
sclerostin inhibits wnt signaling through tandem interaction with two lrp6 ectodomains.low-density lipoprotein receptor-related protein 6 (lrp6) is a coreceptor of the β-catenin-dependent wnt signaling pathway. the lrp6 ectodomain binds wnt proteins, as well as wnt inhibitors such as sclerostin (sost), which negatively regulates wnt signaling in osteocytes. although lrp6 ectodomain 1 (e1) is known to interact with sost, several unresolved questions remain, such as the reason why sost binds to lrp6 e1e2 with higher affinity than to the e1 domain alone. here, we present the crystal ...202033097721
rad21 is involved in corneal stroma development by regulating neural crest migration.previously, we identified rad21r450c from a peripheral sclerocornea pedigree. injection of this rad21 variant mrna into xenopus laevis embryos disrupted the organization of corneal stroma fibrils. to understand the mechanisms of rad21-mediated corneal stroma defects, gene expression and chromosome conformation analysis were performed using cells from family members affected by peripheral sclerocornea. both gene expression and chromosome conformation of cell adhesion genes were affected in cells ...202033096935
phosphoproteomic analysis of xenopus laevis reveals expression and phosphorylation of hypoxia-inducible pfkfb3 during dehydration.xenopus laevis tolerate dehydration when their environments evaporate during summer months. protein phosphorylation has previously shown to regulate important adaptations in x. laevis, including the transition to anaerobic metabolism. we therefore performed phosphoproteomic analysis of x. laevis to further elucidate the cellular and metabolic responses to dehydration. phosphoproteins were enriched in cellular functions and pathways related to glycolysis/gluconeogenesis, the tca cycle, and protei ...202033083755
derivation of proliferative islet1-positive cells during metamorphosis and wound response in xenopus.in mammalian hearts, cardiomyocytes retain a transient capacity to proliferate and regenerate following injury before birth, whereas they lose proliferative capacity immediately after birth. it has also been known that cardiac progenitor cells including islet1-positive cells do not contribute to the cardiac repair and regeneration in mammals. in contrast, hearts of zebrafish, amphibians and reptiles maintain a regenerative ability throughout life. here, we analyzed proliferative capacity of card ...202033070205
non-junctional role of cadherin3 in cell migration and contact inhibition of locomotion via domain-dependent, opposing regulation of rac1.classical cadherins are well-known adhesion molecules responsible for physically connecting neighboring cells and signaling this cell-cell contact. recent studies have suggested novel signaling roles for "non-junctional" cadherins (njcads); however, the function of cadherin signaling independent of cell-cell contacts remains unknown. in this study, mesendodermal cells and tissues from gastrula stage xenopus laevis embryos demonstrate that deletion of extracellular domains of cadherin3 (cdh3; for ...202033060598
scorpion toxin meunatxα-1 sensitizes primary nociceptors by selective modulation of voltage-gated sodium channels.venoms are a rich source of highly specific toxins, which allow the identification of novel therapeutic targets. we have now applied high content screening (hcs) microscopy to identify toxins that modulate pain sensitization signaling in primary sensory neurons of rat and elucidated the underlying mechanism. a set of venoms and fractions thereof were analyzed for their ability to activate type ii protein kinase a (pka-ii) and extracellular signal-regulated kinases (erk1/2). we identified meunatx ...202033051988
glutamate, d-(-)-2-amino-5-phosphonopentanoic acid, and n-methyl-d-aspartate do not directly modulate glycine receptors.replication studies play an essential role in corroborating research findings and ensuring that subsequent experimental works are interpreted correctly. a previously published paper indicated that the neurotransmitter glutamate, along with the compounds n-methyl-d-aspartate (nmda) and d-(-)-2-amino-5-phosphonopentanoic acid (ap5), acts as positive allosteric modulators of inhibitory glycine receptors. the paper further suggested that this form of modulation would play a role in setting the spina ...202033051383
whole-brain calcium imaging in larval xenopus.sensory systems detect environmental stimuli and transform them into electrical activity patterns interpretable by the central nervous system. en route to higher brain centers, the initial sensory input is successively transformed by interposed secondary processing centers. mapping the neuronal activity patterns at all of those stages is essential to understand sensory information processing. larval xenopus laevis is very well-suited for whole-brain imaging of neuronal activity. this is mainly d ...202033037078
elucidating the framework for specification and determination of the embryonic retina.how cell determination is regulated remains a major unsolved problem in developmental biology. the early embryonic rudiments of many tissues and organs are difficult or impossible to identify, isolate and study at the time when determination occurs. we have examined the commitment process leading to retina formation in xenopus laevis, where presumptive eye tissue can be identified and studied to assay its biological properties during the events leading up to determination. we find that for the r ...202033031807
microtubule-dependent pushing forces contribute to long-distance aster movement and centration in xenopus laevis egg extracts.during interphase of the eukaryotic cell cycle, the microtubule (mt) cytoskeleton serves as both a supportive scaffold for organelles and an arborized system of tracks for intracellular transport. at the onset of mitosis, the position of the astral mt network, specifically its center, determines the eventual location of the spindle apparatus and ultimately the cytokinetic furrow. positioning of the mt aster often results in its movement to the center of a cell, even in large blastomeres hundreds ...202033026931
cross-talk between p2x and nmda receptors.purinergic p2x receptors (p2x) are atp-gated ion channels widely expressed in the cns. while the direct contribution of p2x to synaptic transmission is uncertain, p2x reportedly affect n-methyl-d-aspartate receptor (nmdar) activity, which has given rise to competing theories on the role of p2x in the modulation of synapses. however, p2x have also been shown to participate in receptor cross-talk: an interaction where one receptor (e.g., p2x2) directly influences the activity of another (e.g., nic ...202033003406
dna content contributes to nuclear size control in xenopus laevis.cells adapt to drastic changes in genome quantity during evolution and cell division by adjusting the nuclear size to exert genomic functions. however, the mechanism by which dna content within the nucleus contributes to controlling the nuclear size remains unclear. here, we experimentally evaluated the effects of dna content by utilizing cell-free xenopus egg extracts and imaging of in vivo embryos. upon manipulation of dna content while maintaining cytoplasmic effects constant, both plateau si ...202032997613
torc1 selectively regulates synaptic maturation and input convergence in the developing visual system.newly synthesized proteins support the development of functional neural circuits and previous work has suggested that dysregulated translation mediates certain forms of autism spectrum disorder (asd). here, we investigated the role of target of rapamycin complex 1 (torc1) in synaptic and dendritic development in vivo in the retinotectal system of xenopus laevis tadpoles. we found that torc1 signaling regulates dendritic growth and branching and that acute over-activation of torc1 by rheb overexp ...202032996262
a survey of barley pip aquaporin ionic conductance reveals ca2+-sensitive hvpip2;8 na+ and k+ conductance.some plasma membrane intrinsic protein (pip) aquaporins can facilitate ion transport. here we report that one of the 12 barley pips (pip1 and pip2) tested, hvpip2;8, facilitated cation transport when expressed in xenopus laevis oocytes. hvpip2;8-associated ion currents were detected with na+ and k+, but not cs+, rb+, or li+, and was inhibited by ba2+, ca2+, and cd2+ and to a lesser extent mg2+, which also interacted with ca2+. currents were reduced in the presence of k+, cs+, rb+, or li+ relativ ...202032992595
inferring a complete genotype-phenotype map from a small number of measured phenotypes.understanding evolution requires detailed knowledge of genotype-phenotype maps; however, it can be a herculean task to measure every phenotype in a combinatorial map. we have developed a computational strategy to predict the missing phenotypes from an incomplete, combinatorial genotype-phenotype map. as a test case, we used an incomplete genotype-phenotype dataset previously generated for the malaria parasite's 'chloroquine resistance transporter' (pfcrt). wild-type pfcrt (pfcrt3d7) lacks signif ...202032991585
the mechanism of nmda receptor hyperexcitation in high pressure helium and hyperbaric oxygen.professional divers exposed to pressures greater than 1.1 mpa may suffer from the high pressure neurological syndrome (hpns). divers who use closed-circuit breathing apparatus face the risk of cns hyperbaric oxygen toxicity (hbotox). both syndromes are characterized by reversible cns hyperexcitability, accompanied by cognitive and motor deficits. previous studies have demonstrated that the hyperexcitability of hpns is induced mainly by nmda receptors (nmdars). in our recent studies, we demonstra ...202032982789
in-cell nmr spectroscopy of functional riboswitch aptamers in eukaryotic cells.we report here the in-cell nmr-spectroscopic observation of the binding of the cognate ligand 2'-deoxyguanosine to the aptamer domain of the bacterial 2'-deoxyguanosine-sensing riboswitch in eukaryotic cells, namely xenopus laevis oocytes and in human hela cells. the riboswitch is sufficiently stable in both cell types to allow for detection of binding of the ligand to the riboswitch. most importantly, we show that the binding mode established by in vitro characterization of this prokaryotic rib ...202032975353
design, synthesis, and in vitro evaluation of p2x7 antagonists.the p2x7 receptor is a promising target for the treatment of various diseases due to its significant role in inflammation and immune cell signaling. this work describes the design, synthesis, and in vitro evaluation of a series of novel derivatives bearing diverse scaffolds as potent p2x7 antagonists. our approach was based on structural modifications of reported (adamantan-1-yl)methylbenzamides able to inhibit the receptor activation. the adamantane moieties and the amide bond were replaced, an ...202032964578
endoparasites infecting exotic captive amphibian pet and zoo animals (anura, caudata) in germany.alongside exotic reptiles, amphibians, such as toads, frogs, salamanders, and newts, are nowadays considered popular pets worldwide. as reported for other exotic pet animals, amphibians are known to harbor numerous gastrointestinal parasites. nonetheless, very little data are available on captive amphibian parasitic diseases. in this study, we applied direct saline fecal smears (dsfs) to examine in total 161 stool samples from 41 different amphibian species belonging to the orders anura and caud ...202032960371
amiodarone bioconcentration and suppression of metamorphosis in xenopus.trace concentrations of a number of pharmaceutically active compounds have been detected in the aquatic environment in many countries, where they are thought to have the potential to exert adverse effects on non-target organisms. amiodarone (amd) is one such high-risk compound commonly used in general hospitals. amd is known to alter normal thyroid hormone (th) function, although little information is available regarding the specific mechanism by which this disruption occurs. anuran tadpole meta ...202032956954
aquaporin expression in the alimentary canal of the honey bee apis mellifera l. (hymenoptera: apidae) and functional characterization of am_eglp 1.aquaporins (aqp) are a family of plasma membrane proteins responsible for water transport through cell membranes. they are differentially expressed in different parts of the alimentary canal of insects where they regulate water transport. these proteins have been studied in detail in some insects, but few data are available for aquaporins of the honey bee, apis mellifera. we used quantitative pcr to study the expression of six putative aquaporin genes in forager honey bees. we found differential ...202032956406
do muscle contractile properties drive differences in locomotor performance in invasive populations of xenopus laevis in france?jumping and swimming are key locomotor traits in frogs intimately linked to survival and dispersal. french populations of the frog xenopus laevis from the invasion front are known to possess greater terrestrial locomotor endurance. here, we tested whether individuals from the invasion front show differences in their muscle physiology that may underlie the observed whole-organism performance differences. we measured muscle contractile properties of the isolated gastrocnemius muscle in vitro, incl ...202032955613
effect of 158 herbal remedies on human trpv1 and the two-pore domain potassium channels kcnk2, 3 and 9.herbal medicines are used to treat a broad number of maladies. however, the pharmacological profile of most remedies is poorly understood. we investigated the effect of herbal remedies from kampo, traditional chinese medicine (tcm) and other phytotherapies on human two-pore domain potassium channels (kcnk channels; trek-1, task-1 and task-3) as well as the human trpv1 channel. kcnk channels are responsible for the background potassium current of excitable cells, thus essential for the maintenanc ...202032953560
exposure impacts of environmentally relevant concentrations of a glufosinate ammonium herbicide formulation on larval development and thyroid histology of xenopus laevis.thyroid hormones play critical roles in body growth and development as well as reproduction. they also influence the activities of a wider variety of tissues and biological functions, such as osmoregulation, metabolism, and especially metamorphosis in organisms, such as frogs. these complex activities of thyroid hormones are prone to disruption by agricultural pesticides, often leading to modulation of growth and the reproductive system in particular. these substances include glufosinate ammoniu ...202032948887
an integrated approach to assess the sublethal effects of colloidal gold nanorods in tadpoles of xenopus laevis.gold nanorods (aunr) have been explored for many applications, including innovative nanomedicines, which also might contribute to its increase in the environment, namely due to inadequate disposable of wastes into aquatic environments. early-life stages of amphibians are usually aquatic and sensitive to chemical contamination. accordingly, this study aimed to determine the sublethal effects of ctab functionalized aunr on xenopus laevis tadpoles. as such, tadpoles were exposed to serial concentra ...202032947686
the transcription factor hypermethylated in cancer 1 (hic1) regulates neural crest migration via interaction with wnt signaling.the transcription factor hypermethylated in cancer 1 (hic1) is associated with both tumorigenesis and the complex human developmental disorder miller-dieker syndrome. while many studies have characterized hic1 as a tumor suppressor, hic1 function in development is less understood. loss-of-function mouse alleles show embryonic lethality accompanied with developmental defects, including craniofacial abnormalities that are reminiscent of human miller-dieker syndrome patients. however, the tissue or ...202032502469
dehydration stress alters the mitogen-activated-protein kinase signaling and chaperone stress response in xenopus laevis.in arid conditions, the african clawed frog xenopus laevis enters a state of estivation dormancy as an adaptive survival strategy. under estivation, x. laevis experience severe dehydration stress as 25-35% of total body water is lost. dehydration in x. laevis can lead to periods of hypoxia due to elevated blood viscosity that impedes tissue perfusion. to understand how x. laevis survives under such stress, we studied the regulation pattern of key mitogen-activated protein kinases (mapk) and thei ...202032497588
altered thyroid hormone levels affect the capacity for temperature-induced developmental plasticity in larvae of rana temporaria and xenopus laevis.anuran larvae show phenotypic plasticity in age and size at metamorphosis as a response to temperature variation. the capacity for temperature-induced developmental plasticity is determined by the thermal adaptation of a population. multiple factors such as physiological responses to changing environmental conditions, however, might influence this capacity as well. in anuran larvae, thyroid hormone (th) levels control growth and developmental rate and changes in th status are a well-known stress ...202032479394
the perinuclear er scales nuclear size independently of cell size in early embryos.nuclear size plays pivotal roles in gene expression, embryo development, and disease. a central hypothesis in organisms ranging from yeast to vertebrates is that nuclear size scales to cell size. this implies that nuclei may reach steady-state sizes set by limiting cytoplasmic pools of size-regulating components. by monitoring nuclear dynamics in early sea urchin embryos, we found that nuclei undergo substantial growth in each interphase, reaching a maximal size prior to mitosis that declined st ...202032473090
association of a novel splice site mutation in p/q-type calcium channels with childhood epilepsy and late-onset slowly progressive non-episodic cerebellar ataxia.episodic ataxia type 2 (ea2) is characterized by paroxysmal attacks of ataxia with typical onset in childhood or early adolescence. the disease is associated with mutations in the voltage-gated calcium channel alpha 1a subunit (cav2.1) that is encoded by the cacna1a gene. however, previously unrecognized atypical symptoms and the genetic overlap existing between ea2, spinocerebellar ataxia type 6, familial hemiplegic migraine type 1, and other neurological diseases blur the genotype/phenotype co ...202032471306
cloning and expression of cockroach α7 nicotinic acetylcholine receptor subunit.understanding insect nicotinic acetylcholine receptor (nachr) subtypes is of major interest because they are the main target of several insecticides. in this study, we have cloned a cockroach pameα7 subunit that encodes a 518 amino acid protein with futures typical of nachr subunit, and sequence homology to α7 subunit. pameα7 is differently expressed in the cockroach nervous system, in particular in the antennal lobes, optical lobes and the mushroom bodies where specific expression was found in ...202032457646
experimental platform using the amphibian xenopus laevis for research in fundamental and medical immunology.the amphibian xenopus constitutes a powerful, versatile, and cost-effective nonmammalian model with which to investigate important contemporary issues of immunity relevant to human health such as ontogeny of immunity, self-tolerance, wound healing, autoimmunity, cancer immunity, immunotoxicology, and adaptation of host immune defenses to emerging pathogens. this model system presents several attractive features: an external developmental environment free of maternal influence that allows for eas ...202032457040
nuclei determine the spatial origin of mitotic waves.traveling waves play an essential role in coordinating mitosis over large distances, but what determines the spatial origin of mitotic waves remains unclear. here, we show that such waves initiate at pacemakers, regions that oscillate faster than their surroundings. in cell-free extracts of xenopus laevis eggs, we find that nuclei define such pacemakers by concentrating cell cycle regulators. in computational models of diffusively coupled oscillators that account for nuclear import, nuclear posi ...202032452767
the regulation of akt and foxo transcription factors during dehydration in the african clawed frog (xenopus laevis).the african clawed frog (xenopus laevis) naturally tolerates severe dehydration using biochemical adaptation, one of which is the elevation of antioxidant defenses during whole-body dehydration. the present study investigated the role and regulation of a pathway known to regulate oxidative stress response, the akt-foxo signaling pathway, in clawed frog skeletal muscle, responding to medium (15%) and high (30%) dehydration. protein levels of total and phosphorylated akt, foxo1, and foxo3 were ass ...202032451989
microvascular anatomy of ovary and oviduct in the adult african clawed toad (xenopus laevis daudin, 1802)-histomorphology and scanning electron microscopy of vascular corrosion casts.ovaries and oviducts of the adult african clawed toad (xenopus laevis daudin, 1802) were studied by light microscopy (lm) of paraplast embedded tissue sections and scanning electron microscopy (sem) of vascular corrosion casts (vccs). histomorphology revealed that ovarian vessels located in the thecal layers. ovarian and interlobar arteries displayed a horse-shoe shaped longitudinally running bundle of vascular smooth muscle cells. follicular blood vessels showed flattened profiles, which were c ...202032449214
optical control of muscular nicotinic channels with azocuroniums, photoswitchable azobenzenes bearing two n-methyl-n-carbocyclic quaternary ammonium groups.by linking two n-methyl-n-carbocyclic quaternary ammonium groups to an azobenzene scaffold in meta- or para-positions we generated a series of photoswitchable neuromuscular ligands for which we coined the term "azocuroniums". these compounds switched between the (e)- and (z)-isomers by light irradiation at 400-450 nm and 335-340 nm, respectively. meta-azocuroniums were potent nicotinic ligands with a clear selectivity for the muscular nachrs compared to neuronal α7 and α4β2 subtypes, showed good ...202032447198
cross-taxa distinctions in mechanisms of developmental effects for aquatic species exposed to trifluralin.standard ecological risk assessment practices often rely on larval and juvenile fish toxicity data as representative of the amphibian aquatic phase. empirical evidence suggests that endpoints measured in fish early life stage tests are often sufficient to protect larval amphibians. however, the process of amphibian metamorphosis relies on endocrine cues that affect development and morphological restructuring and are not represented by these test endpoints. the present study compares developmenta ...202032445211
identification of transient receptor potential channel 4-associated protein as a novel candidate gene causing congenital primary hypothyroidism.congenital primary hypothyroidism (ch) is the most common endocrine disorder in neonates.202032428920
de novo mutations in fbrsl1 cause a novel recognizable malformation and intellectual disability syndrome.we report truncating de novo variants in specific exons of fbrsl1 in three unrelated children with an overlapping syndromic phenotype with respiratory insufficiency, postnatal growth restriction, microcephaly, global developmental delay and other malformations. the function of fbrsl1 is largely unknown. interestingly, mutations in the fbrsl1 paralogue auts2 lead to an intellectual disability syndrome (auts2 syndrome). we determined human fbrsl1 transcripts and describe protein-coding forms by we ...202032424618
imaging nascent transcription in wholemount vertebrate embryos to characterize zygotic genome activation.a major event in early embryo development is the awakening of the embryonic genome, a process of large-scale transcriptional induction termed zygotic genome activation (zga). to understand how zga is controlled temporally and spatially, tools are required to image and quantify nascent transcription in wholemount embryos. in this chapter, we describe a metabolic labeling approach that leverages 5-ethynyl uridine (5-eu) incorporation into newly transcribed rnas. subsequently, click chemistry is us ...202032416911
supportive role of the na+ transporter cmhkt1;1 from cucumis melo in transgenic arabidopsis salt tolerance through improved k+/na+ balance.cmhkt1;1 selectively exports na+ from plant cells. upon nacl stress, its expression increased in a salt-tolerant melon cultivar. overexpression of cmhkt1;1 increased transgenic arabidopsis salt tolerance through improved k+/na+ balance. high-affinity k+ transporters (hkts) are thought to be involved in reducing na+ in plant shoots under salt stress and modulating salt tolerance, but their function in a moderately salt-tolerant species of melon (cucumis melo l.) remains unclear. in this study, a ...202032405802
animal maintenance systems: xenopus laevis.modular recirculating animal aquaculture systems incorporate uv sterilization and biological, mechanical, and activated carbon filtration, creating a nearly self-contained stable housing environment for xenopus laevis nonetheless, minimal water exchange is necessary to mitigate accumulation of metabolic waste, and regular weekly, monthly, and yearly maintenance is needed to ensure accurate and efficient operation. this protocol describes the methods for establishing a new recirculating system an ...202032404311
altered functional properties of a missense variant in the tresk k+ channel (kcnk18) associated with migraine and intellectual disability.mutations in the kcnk18 gene that encodes the tresk k2p potassium channel have previously been linked with typical familial migraine with aura. recently, an atypical clinical case has been reported in which a male individual carrying the p.trp101arg (w101r) missense mutation in the kcnk18 gene was diagnosed with intellectual disability and migraine with brainstem aura. here we report the functional characterization of this new missense variant. this mutation is located in a highly conserved resi ...202032394190
managing the oocyte meiotic arrest-lessons from frogs and jellyfish.during oocyte development, meiosis arrests in prophase of the first division for a remarkably prolonged period firstly during oocyte growth, and then when awaiting the appropriate hormonal signals for egg release. this prophase arrest is finally unlocked when locally produced maturation initiation hormones (mihs) trigger entry into m-phase. here, we assess the current knowledge of the successive cellular and molecular mechanisms responsible for keeping meiotic progression on hold. we focus on tw ...202032392797
differences in intrinsic tubulin dynamic properties contribute to spindle length control in xenopus species.the function of cellular organelles relates not only to their molecular composition but also to their size. however, how the size of dynamic mesoscale structures is established and maintained remains poorly understood [1-3]. mitotic spindle length, for example, varies several-fold among cell types and among different organisms [4]. although most studies on spindle size control focus on changes in proteins that regulate microtubule dynamics [5-8], the contribution of the spindle's main building b ...202032386526
structure of the cytoplasmic ring of the xenopus laevis nuclear pore complex by cryo-electron microscopy single particle analysis.the nuclear pore complex (npc) exhibits structural plasticity and has only been characterized at local resolutions of up to 15 å for the cytoplasmic ring (cr). here we present a single-particle cryo-electron microscopy (cryo-em) structure of the cr from xenopus laevis npc at average resolutions of 5.5-7.9 å, with local resolutions reaching 4.5 å. improved resolutions allow identification and placement of secondary structural elements in the majority of the cr components. the two y complexes in e ...202032376910
rpe cells engulf microvesicles secreted by degenerating rod photoreceptors.rhodopsin is mislocalized to the inner segment plasma membrane (is pm) in various blinding disorders including autosomal-dominant retinitis pigmentosa caused by class i rhodopsin mutations. in these disorders, rhodopsin-laden microvesicles are secreted into the extracellular milieu by afflicted photoreceptor cells. using a xenopus laevis model expressing class i mutant rhodopsin or na+/k+-atpase (nka) fused to dendra2, we fluorescently labeled the microvesicles and found retinal pigment epitheli ...202032376599
renal microvasculature in the adult pipid frog, xenopus laevis: a scanning electron microscope study of vascular corrosion casts.we studied the opisthonephric (mesonephric) kidneys of adult male and female xenopus laevis using scanning electron microscopy (sem) of vascular corrosion casts and light microscopy of paraplast embedded tissue sections. both techniques displayed glomeruli from ventral to mid-dorsal regions of the kidneys with single glomeruli located dorsally close beneath the renal capsule. glomeruli in general were fed by a single afferent arteriole and drained via a single thinner efferent arteriole into per ...202032374496
molecular characterization of frog vocal neurons using constellation pharmacology.identification and characterization of neuronal cell classes in motor circuits are essential for understanding the neural basis of behavior. it is a challenging task, especially in a non-genetic-model organism, to identify cell-specific expression of functional macromolecules. here, we performed constellation pharmacology, calcium imaging of dissociated neurons to pharmacologically identify functional receptors expressed by vocal neurons in adult male and female african clawed frogs, xenopus lae ...202032374212
the gria3 c.2477g > a variant causes an exaggerated startle reflex, chorea, and multifocal myoclonus.hemizygous mutations in gria3 encoding the glua3 subunit of the amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are known to be associated with neurodevelopmental disorders, including intellectual disability, hypotonia, an autism spectrum disorder, sleep disturbances, and epilepsy in males.202032369665
molecular architecture of the luminal ring of the xenopus laevis nuclear pore complex.the nuclear pore complex (npc) mediates the flow of substances between the nucleus and cytoplasm in eukaryotic cells. here we report the cryo-electron tomography (cryo-et) structure of the luminal ring (lr) of the npc from xenopus laevis oocyte. the observed key structural features of the lr are independently confirmed by single-particle cryo-electron microscopy (cryo-em) analysis. the lr comprises eight butterfly-shaped subunits, each containing two symmetric wings. each wing consists of four e ...202032367042
stentian structural plasticity in the developing visual system.in a small fraction of xenopus tadpoles, a single retinal ganglion cell (rgc) axon misprojects to the ipsilateral optic tectum. presenting flashes of light to the ipsilateral eye causes that ipsilateral axon to fire, whereas stimulating the contralateral eye excites all other rgc inputs to the tectum. we performed time-lapse imaging of individual ipsilaterally projecting axons while stimulating either the ipsilateral or contralateral eye. stimulating either eye alone reduced axon elaboration by ...202032366647
combining endocannabinoids with retigabine for enhanced m-channel effect and improved kv7 subtype selectivity.retigabine is unique among anticonvulsant drugs by targeting the neuronal m-channel, which is composed of kv7.2/kv7.3 and contributes to the negative neuronal resting membrane potential. unfortunately, retigabine causes adverse effects, which limits its clinical use. adverse effects may be reduced by developing m-channel activators with improved kv7 subtype selectivity. the aim of this study was to evaluate the prospect of endocannabinoids as m-channel activators, either in isolation or combined ...202032365171
functional characterization of multifunctional ligands targeting acetylcholinesterase and alpha 7 nicotinic acetylcholine receptor.alzheimer's disease (ad) is a neurodegenerative disorder associated with cholinergic dysfunction, provoking memory loss and cognitive dysfunction in elderly patients. the cholinergic hypothesis provided over the years with molecular targets for developing palliative treatments for ad, acting on the cholinergic system, namely, acetylcholinesterase and α7 nicotinic acetylcholine receptor (α7 nachr). in our synthetic work, we used "click-chemistry" to synthesize two multi target directed ligands (m ...202032360492
inhibition of cardiac kv4.3 (ito) channel isoforms by class i antiarrhythmic drugs lidocaine and mexiletine.transient outward k+ current, ito, contributes to cardiac action potential generation and is primarily carried by kv4.3 (kcnd3) channels. two kv4.3 isoforms are expressed in human ventricle and show differential remodeling in heart failure (hf). lidocaine and mexiletine may be applied in selected patients to suppress ventricular arrhythmias, without effects on sudden cardiac death or mortality. isoform-dependent effects of antiarrhythmic drugs on kv4.3 channels and potential implications for rem ...202032360350
effects of ferrocenyl 4-(imino)-1,4-dihydro-quinolines on xenopus laevis prophase i - arrested oocytes: survival and hormonal-induced m-phase entry.xenopus oocytes were used as cellular and molecular sentinels to assess the effects of a new class of organometallic compounds called ferrocenyl dihydroquinolines that have been developed as potential anti-cancer agents. one ferrocenyl dihydroquinoline compound exerted deleterious effects on oocyte survival after 48 h of incubation at 100 μm. two ferrocenyl dihydroquinoline compounds had an inhibitory effect on the resumption of progesterone induced oocyte meiosis, compared to controls without f ...202032357477
structure of a single-chain h2a/h2b dimer.chromatin is the complex assembly of nucleic acids and proteins that makes up the physiological form of the eukaryotic genome. the nucleosome is the fundamental repeating unit of chromatin, and is composed of ∼147 bp of dna wrapped around a histone octamer formed by two copies of each core histone: h2a, h2b, h3 and h4. prior to nucleosome assembly, and during histone eviction, histones are typically assembled into soluble h2a/h2b dimers and h3/h4 dimers and tetramers. a multitude of factors inte ...202032356520
how to grow xenopus laevis tadpole stages to adult.in xenopus laevis, the tadpole stage is characterized by three forms-those occurring before the initiation of limb development, those covering limb development, and those encompassing metamorphosis. maximal tadpole growth, especially during the second form, is critically dependent on good husbandry practices. here we describe a protocol for raising xenopus laevis tadpoles through to adulthood. each step may need to be modified depending on the aquaria used and local conditions.202032350123
effect of nano-encapsulation of β-carotene on xenopus laevis embryos development (fetax).vitamin a plays a vital role during embryo development as most precursor of embryonic retinoic acid, a key morphogen during embryogenesis. carotenoids, including β-carotene, are important vegetal source of vitamin a and in contrast to teratogenic potential of animal-derived retinoids, β-carotene is usually considered freed from embryotoxic effects and supplements in pregnancy with β-carotene are suggested. the aim of the present work is to evaluate the effect of bulk and nano-encapsulated β-caro ...202032346517
concentration-dependent physiological and transcriptional adaptations of wheat seedlings to ammonium.conventional wheat production utilizes fertilizers of various nitrogen forms. sole ammonium nutrition has been shown to improve grain quality, despite the potential toxic effects of ammonium at elevated concentrations. we therefore investigated the responses of young seedlings of winter wheat to different nitrogen sources (nh4 no3 = nn, nh4 cl = nnh4+ and kno3 = nno3- ). growth with ammonium-nitrate was superior. however, an elevated concentration of sole ammonium caused severe toxicity symptoms ...202032335941
transcriptional changes caused by estrogenic endocrine disrupting chemicals in gonad-mesonephros complexes of genetic male xenopus laevis: multiple biomarkers for early detection of testis differentiation disruption.our recent study revealed some early molecular and cellular events in which 17β-estradiol (e2) disrupted testis differentiation and resulted in feminization in xenopus laevis (the african clawed frog), an ideal species for studying reproductive endocrine disruption by estrogenic endocrine disrupting chemicals (edcs). on this basis, we aimed to develop multiple biomarkers for early detection of testis differentiation disruption by estrogenic edcs in x. laevis. tadpoles at stage 45/46 were exposed ...202032335401
the abcf gene family facilitates disaggregation during animal development.protein aggregation, once believed to be a harbinger and/or consequence of stress, age, and pathological conditions, is emerging as a novel concept in cellular regulation. normal versus pathological aggregation may be distinguished by the capacity of cells to regulate the formation, modification, and dissolution of aggregates. we find that caenorhabditis elegans aggregates are observed in large cells/blastomeres (oocytes, embryos) and in smaller, further differentiated cells (primordial germ cel ...202032320318
spadin selectively antagonizes arachidonic acid activation of trek-1 channels.trek-1 channel activity is a critical regulator of neuronal, cardiac, and smooth muscle physiology and pathology. the antidepressant peptide, spadin, has been proposed to be a trek-1-specific blocker. here we sought to examine the mechanism of action underlying spadin inhibition of trek-1 channels. heterologous expression in xenopus laevis oocytes and electrophysiological analysis using two-electrode voltage clamp in standard bath solutions was used to characterize the pharmacological profile of ...202032317978
effect of salinity acclimation on osmoregulation, oxidative stress, and metabolic enzymes in the invasive xenopus laevis.aquatic animals often display physiological adjustments to improve their biological performance and hydrosaline balance in saline environments. in addition to energetic costs associated with osmoregulation, oxidative stress, and the activation of the antioxidant system are common cellular responses to salt stress in many species, but the knowledge of osmoregulation-linked oxidative homeostasis in amphibians is scarce. here we studied the biochemical responses and oxidative responses of xenopus l ...202032306529
preparation of soluble malectin and its tetramer.malectin is a membrane-anchored endoplasmic reticulum (er)-resident lectin, which is first identified in xenopus laevis in 2008 and highly conserved among animals. malectin plays an important role in the quality control of glycoprotein in the er through recognizing the glc2man9glcnac2 (g2m9) oligosaccharide chain on the newly synthesized glycoproteins. in this chapter, we will describe the preparation of recombinant soluble malectin and its tetramer, which might be developed as useful tools for ...202032306336
neurotoxin merging: a strategy deployed by the venom of the spider cupiennius salei to potentiate toxicity on insects.the venom of cupiennius salei is composed of dozens of neurotoxins, with most of them supposed to act on ion channels. some insecticidal monomeric neurotoxins contain an α-helical part besides their inhibitor cystine knot (ick) motif (type 1). other neurotoxins have, besides the ick motif, an α-helical part of an open loop, resulting in a heterodimeric structure (type 2). due to their low toxicity, it is difficult to understand the existence of type 2 peptides. here, we show with the voltage cla ...202032290562
multidirectional changes in parameters related to sulfur metabolism in frog tissues exposed to heavy metal-related stress.the investigations showed changes of the cystathionine γ-lyase (cth), 3-mercaptopyruvate sulfurtransferase (mpst) and rhodanese (tst) activity and gene expression in the brain, heart, liver, kidney, skeletal muscles and testes in frogs pelophylaxridibundus, xenopuslaevis and xenopus tropicalis in response to pb2+, hg2+ and cd2+ stress. the results were analyzed jointly with changes in the expression of selected antioxidant enzymes (cytoplasmic and mitochondrial superoxide dismutase, glutathione ...202032283689
a generalizable optogenetic strategy to regulate receptor tyrosine kinases during vertebrate embryonic development.ligand-independent activation of receptor tyrosine kinases (rtks) allows for dissecting out the receptor-specific signaling outcomes from the pleiotropic effects of the ligands. in this regard, rtk intracellular domains (icd) are of interest due to their ability to recapitulate signaling activity in a ligand-independent manner when fused to chemical or optical dimerizing domains. a common strategy for synthetic activation of rtks involves membrane tethering of dimerizer-rtk icd fusions. dependin ...202032277988
simple embryo injection of long single-stranded donor templates with the crispr/cas9 system leads to homology-directed repair in xenopus tropicalis and xenopus laevis.we report model experiments in which simple microinjection of fertilized eggs has been used to effectively perform homology-directed repair (hdr)-mediated gene editing in the two xenopus species used most frequently for research: x. tropicalis and x. laevis. we have used long single-stranded dnas having phosphorothioate modifications as donor templates for hdr at targeted genomic sites using the clustered regularly interspaced short palindromic repeats/crispr-associated protein 9 (crispr/cas9) s ...202032277804
toward the understanding of biology of oocyte life cycle in xenopus laevis: no oocytes left behind.for the past more than 25 years, we have been focusing on the developmental and reproductive biology of the female gametes, oocytes, and eggs, of the african clawed frog xenopus laevis.202032273815
nastep, an essential protein for self-incompatibility in nicotiana, performs a dual activity as a proteinase inhibitor and as a voltage-dependent channel blocker.the s-specific pollen rejection response in nicotiana depends on the interaction between s-rnase and a suite of slf proteins. however, the biochemical pathway requires other essential proteins. one of them is the stigmatic protein nastep, which belongs to the kunitz-type protease inhibitor family. within the pollen tubes, nastep is a positive regulator of ht-b stability, likely inhibiting its degradation and, additionally, interacts with nasipp, a mitochondrial phosphate carrier. to gain a deepe ...202032272353
isolation and characterization of a novel member of the acc ligand-gated chloride channel family, hco-lcg-46, from the parasitic nematode haemonchus contortus.the acc-1 family of cys-loop receptors are ligand-gated chloride channels sensitive to acetylcholine (ach), and are only present in invertebrates. studies of this family of inhibitory receptors has provided insight into how they bind and respond to ach in a manner vastly different from nicotinic acetylcholine receptors and appear to be present in tissues that are relevant to anthelmintic action. here, we have identified two members of the acc-1 family from the parasitic nematode haemonchus conto ...202032268182
the tumor suppressor tff1 occurs in different forms and interacts with multiple partners in the human gastric mucus barrier: indications for diverse protective functions.tff1 is a protective peptide of the trefoil factor family (tff), which is co-secreted with the mucin muc5ac, gastrokine 2 (gkn2), and igg fc binding protein (fcgbp) from gastric surface mucous cells. tff1-deficient mice obligatorily develop antropyloric adenoma and about 30% progress to carcinomas, indicating that tff1 is a tumor suppressor. as a hallmark, tff1 contains seven cysteine residues with three disulfide bonds stabilizing the conserved tff domain. here, we systematically investigated t ...202032260357
microrna expression in the heart of xenopus laevis facilitates metabolic adaptation to dehydration.xenopus laevis survive severe dehydration during the summer months in their natural range. microrna regulate translation of target mrnas and have shown to be differentially expressed in response to dehydration in x. laevis. during dehydration, heart rate is elevated which appears to compensate for the reduced oxygen delivery capability due to increased hematocrit. we hypothesized that micrornas would be differentially expressed in the heart to modulate gene expression levels in response to dehyd ...202032259572
natural size variation among embryos leads to the corresponding scaling in gene expression.xenopus laevis frogs from laboratory stocks normally lay eggs exhibiting extensive size variability. we find that these initial size differences subsequently affect the size of the embryos prior to the onset of growth, and the size of tadpoles during the growth period. even though these tadpoles differ in size, their tissues, organs, and structures always seem to be properly proportioned, i.e. they display static allometry. initial axial patterning events in xenopus occur in a spherical embryo, ...202032259520
pact/prkra and p53 regulate transcriptional activity of dmrt1.the transcription factor dmrt1 (doublesex and mab-3 related transcription factor) has two distinct functions, somatic-cell masculinization and germ-cell development in some vertebrate species, including mouse and the african clawed frog xenopus laevis. however, its transcriptional regulation remains unclear. we tried to identify dmrt1-interacting proteins from x. laevis testes by immunoprecipitation with an anti-dmrt1 antibody and ms/ms analysis, and selected three proteins, including pact/prkra ...202032251494
αm-conotoxin miiij blocks nicotinic acetylcholine receptors at neuromuscular junctions of frog and fish.we report the discovery and functional characterization of αm-conotoxin miiij, a peptide from the venom of the fish-hunting cone snail conus magus. injections of αm-miiij induced paralysis in goldfish (carassius auratus) but not mice. intracellular recording from skeletal muscles of fish (c. auratus) and frog (xenopus laevis) revealed that αm-miiij inhibited postsynaptic nicotinic acetylcholine receptors (nachrs) with an ic50 of ~0.1 μm. with comparable potency, αm-miiij reversibly blocked ach-g ...202032245200
trefoil factor family (tff) modules are characteristic constituents of separate mucin complexes in the xenopus laevis integumentary mucus: in vitro binding studies with fim-a.1.the skin of the frog xenopus laeevis is protected from microbial infections by a mucus barrier that contains frog integumentary mucins (fim)-a.1, fim-b.1, and fim-c.1. these gel-forming mucins are synthesized in mucous glands consisting of ordinary mucous cells and one or more cone cells at the gland base. fim-a.1 and fim-c.1 are unique because their cysteine-rich domains belong to the trefoil factor family (tff). furthermore, fim-a.1 is unusually short (about 400 amino acid residues). in contra ...202032244312
4-hydroxynonenal induces cx46 hemichannel inhibition through its carbonylation.hemichannels formed by connexins mediate the exchange of ions and signaling molecules between the cytoplasm and the extracellular milieu. under physiological conditions hemichannels have a low open probability, but in certain pathologies their open probability increases, which can result in cell damage. pathological conditions are characterized by the production of a number of proinflammatory molecules, including 4-hydroxynonenal (4-hne), one of the most common lipid peroxides produced in respon ...202032244060
water-soluble variant of human lynx1 positively modulates synaptic plasticity and ameliorates cognitive impairment associated with α7-nachr dysfunction.lynx1 is a gpi-tethered protein colocalized with nicotinic acetylcholine receptors (nachrs) in the brain areas important for learning and memory. previously, we demonstrated that at low micromolar concentrations the water-soluble lynx1 variant lacking gpi-anchor (ws-lynx1) acts on α7-nachrs as a positive allosteric modulator. we hypothesized that ws-lynx1 could be used for improvement of cognitive processes dependent on nachrs. here we showed that 2 µm ws-lynx1 increased the acetylcholine-evoked ...202032222974
effects of syntaxins 2, 3, and 4 on rat and human epithelial sodium channel (enac) in xenopus laevis oocytes.syntaxins are snare proteins and may play a role in epithelial sodium channel (enac) trafficking. the aim of the present study was to investigate the effects of syntaxin 2 (stx2), syntaxin 3 (stx3), and syntaxin 4 (stx4) on rat (renac) and human enac (henac). co-expression of renac and stx3 or stx4 in xenopus laevis oocytes increased amiloride-sensitive whole-cell currents (δiami) on average by 50% and 135%, respectively, compared to oocytes expressing renac alone. in contrast, stx2 had no signi ...202032221667
effect assessment of reclaimed water and carbamazepine exposure on the thyroid axis of x. laevis: apical and histological effects.there is increasing environmental concern about the constant presence of pharmaceuticals and personal care products (ppcps) in surface water, generally attributed to water discharge from wastewater treatment plants (wwtps) that are unable to completely remove these compounds. the slight, but continuous, presence of these contaminants in reclaimed water (rw) poses a risk of chronic and sublethal toxicity, and the thyroid axis can likely be a target of many of these ppcps. in this work, we address ...202032220735
Refresh
firstprev
...171172
nextlast
Displaying items 17001 - 17100 of 17138