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1.
Proc Natl Acad Sci U S A ; 121(4): e2317452121, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38236729

ABSTRACT

Bacterial flagella and type IV pili (TFP) are surface appendages that enable motility and mechanosensing through distinct mechanisms. These structures were previously thought to have no components in common. Here, we report that TFP and some flagella share proteins PilO, PilN, and PilM, which we identified as part of the Helicobacter pylori flagellar motor. H. pylori mutants lacking PilO or PilN migrated better than wild type in semisolid agar because they continued swimming rather than aggregated into microcolonies, mimicking the TFP-regulated surface response. Like their TFP homologs, flagellar PilO/PilN heterodimers formed a peripheral cage that encircled the flagellar motor. These results indicate that PilO and PilN act similarly in flagella and TFP by differentially regulating motility and microcolony formation when bacteria encounter surfaces.


Subject(s)
Bacterial Proteins , Fimbriae, Bacterial , Bacterial Proteins/metabolism , Fimbriae, Bacterial/genetics , Fimbriae, Bacterial/metabolism , Bacteria , Flagella/physiology
2.
Plants (Basel) ; 12(14)2023 Jul 22.
Article in English | MEDLINE | ID: mdl-37514343

ABSTRACT

Plants of the Phoradendron genus have been traditionally used for their lipid- and glucose-lowering effects. However, the compounds responsible for these effects and the overall chemical profile of these plants have not been thoroughly investigated. We aimed to characterize the metabolome of leaves, stems, and aerial parts of the Phoradendron brachystachyum plant. We used mass spectrometry and colorimetric screening techniques (with various solvents) to identify and characterize the metabolites present. We also evaluated the antioxidant (FRAP, ORAC, TEAC, and DPPH assays) and inhibitory effects on pancreatic lipase and α-glucosidase enzymes of hydrophilic extracts. Furthermore, we compared the molecular fingerprints between the identified metabolites and FDA-approved drugs to gain insights into the metabolites that might be responsible for the observed effects on enzymes. Our findings revealed the presence of 59 putative metabolites, primarily flavonoids. However, we also hint at the presence of peptide and carbohydrate derivatives. The leaf extracts demonstrated the most promising metrics across all assays, exhibiting strong antioxidant and enzyme inhibitory effects as well as high levels of phenolic compounds, flavonoids, and tannins. Fingerprint analysis suggested potential peptide and carbohydrate metabolites as pancreatic lipase and α-glucosidase inhibitors. Overall, our study provides evidence on specific metabolites in Phoradendron brachystachyum that could be responsible for the therapeutic effects noted in obese and type 2 diabetes subjects.

3.
Front Synaptic Neurosci ; 15: 1176864, 2023.
Article in English | MEDLINE | ID: mdl-37252636

ABSTRACT

Cannabis exposure during gestation evokes significant molecular modifications to neurodevelopmental programs leading to neurophysiological and behavioral abnormalities in humans. The main neuronal receptor for Δ9-tetrahydrocannabinol (THC) is the type-1 cannabinoid receptor CB1R, one of the most abundant G-protein-coupled receptors in the nervous system. While THC is the major psychoactive phytocannabinoid, endocannabinoids (eCBs) are the endogenous ligands of CB1R and are known to act as retrograde messengers to modulate synaptic plasticity at different time scales in the adult brain. Accumulating evidence indicates that eCB signaling through activation of CB1R plays a central role in neural development. During development, most CB1R localized to axons of projection neurons, and in mice eCB signaling impacts axon fasciculation. Understanding of eCB-mediated structural plasticity during development, however, requires the identification of the precise spatial and temporal dynamics of CB1R-mediated modifications at the level of individual neurons in the intact brain. Here, the cell-autonomous role of CB1R and the effects of CB1R-mediated eCB signaling were investigated using targeted single-cell knockdown and pharmacologic treatments in Xenopus. We imaged axonal arbors of retinal ganglion cells (RGCs) in real time following downregulation of CB1R via morpholino (MO) knockdown. We also analyzed RGC axons with altered eCB signaling following treatment with URB597, a selective inhibitor of the enzyme that degrades Anandamide (AEA), or JZL184, an inhibitor of the enzyme that blocks 2-Arachidonoylglycerol (2-AG) hydrolysis, at two distinct stages of retinotectal development. Our results demonstrate that CB1R knockdown impacts RGC axon branching at their target and that differential 2-AG and AEA-mediated eCB signaling contributes to presynaptic structural connectivity at the time that axons terminate and when retinotectal synaptic connections are made. Altering CB1R levels through CB1R MO knockdown similarly impacted dendritic morphology of tectal neurons, thus supporting both pre- and postsynaptic cell-autonomous roles for CB1R-mediated eCB signaling.

4.
Front Immunol ; 14: 1107497, 2023.
Article in English | MEDLINE | ID: mdl-36845106

ABSTRACT

Introduction: The antigen presentation molecule MHC class I related protein-1 (MR1) is best characterized by its ability to present bacterially derived metabolites of vitamin B2 biosynthesis to mucosal-associated invariant T-cells (MAIT cells). Methods: Through in vitro human cytomegalovirus (HCMV) infection in the presence of MR1 ligand we investigate the modulation of MR1 expression. Using coimmunoprecipitation, mass spectrometry, expression by recombinant adenovirus and HCMV deletion mutants we investigate HCMV gpUS9 and its family members as potential regulators of MR1 expression. The functional consequences of MR1 modulation by HCMV infection are explored in coculture activation assays with either Jurkat cells engineered to express the MAIT cell TCR or primary MAIT cells. MR1 dependence in these activation assays is established by addition of MR1 neutralizing antibody and CRISPR/Cas-9 mediated MR1 knockout. Results: Here we demonstrate that HCMV infection efficiently suppresses MR1 surface expression and reduces total MR1 protein levels. Expression of the viral glycoprotein gpUS9 in isolation could reduce both cell surface and total MR1 levels, with analysis of a specific US9 HCMV deletion mutant suggesting that the virus can target MR1 using multiple mechanisms. Functional assays with primary MAIT cells demonstrated the ability of HCMV infection to inhibit bacterially driven, MR1-dependent activation using both neutralizing antibodies and engineered MR1 knockout cells. Discussion: This study identifies a strategy encoded by HCMV to disrupt the MR1:MAIT cell axis. This immune axis is less well characterized in the context of viral infection. HCMV encodes hundreds of proteins, some of which regulate the expression of antigen presentation molecules. However the ability of this virus to regulate the MR1:MAIT TCR axis has not been studied in detail.


Subject(s)
Mucosal-Associated Invariant T Cells , Humans , Histocompatibility Antigens Class I , Cytomegalovirus/metabolism , Minor Histocompatibility Antigens , Receptors, Antigen, T-Cell/metabolism
5.
Exp Gerontol ; 173: 112108, 2023 03.
Article in English | MEDLINE | ID: mdl-36708752

ABSTRACT

We characterized long-term changes in cardiac structure and function in a high-fat diet/streptozotocin mouse model of aging and type 2 diabetes mellitus (T2D) and examined how the intersection of both conditions alters plasma metabolomics. We also evaluated the possible roles played by oxidative stress, arginase activity and pro-inflammatory cytokines. C57BL/6 male mice (13-month-old) were used. Control animals (n = 13) were fed regular chow for 10 months (aged group). T2D animals (n = 25) were provided a single injection of streptozotocin and fed a high fat diet for 10 months. In select endpoints, young animals were used for comparison. To monitor changes in left ventricular (LV) structure and function, echocardiography was used. At the terminal study (23 months), blood was collected and hearts processed for biochemical or histological analysis. Echo yielded diminished diastolic function with aging and T2D. LV fractional shortening and ejection fraction decreased with T2D by 16 months peaking at 23 months. Western blots noted increases in fibronectin and type I collagen with aging/T2D and greater levels with T2D in α-smooth muscle actin. Increases in plasma and/or myocardial protein carbonyls, arginase activity and pro-inflammatory cytokines occurred with aging and T2D. Untargeted metabolomics and cheminformatics revealed differences in the plasma metabolome of T2D vs. aged mice while select classes of lipid metabolites linked to insulin resistance, were dysregulated. We thus, document changes in LV structure and function with aging that in select endpoints, are accentuated with T2D and link them to increases in OS, arginase activity and pro-inflammatory cytokines.


Subject(s)
Diabetes Mellitus, Type 2 , Male , Mice , Animals , Diabetes Mellitus, Type 2/metabolism , Myocardium/metabolism , Arginase/metabolism , Streptozocin/metabolism , Mice, Inbred C57BL , Aging , Cytokines/metabolism
6.
Front Cell Dev Biol ; 10: 1053139, 2022.
Article in English | MEDLINE | ID: mdl-36506089

ABSTRACT

Human cytomegalovirus (HCMV) is a ubiquitous human pathogen that can cause severe disease in immunocompromised individuals, transplant recipients, and to the developing foetus during pregnancy. There is no protective vaccine currently available, and with only a limited number of antiviral drug options, resistant strains are constantly emerging. Successful completion of HCMV replication is an elegant feat from a molecular perspective, with both host and viral processes required at various stages. Remarkably, HCMV and other herpesviruses have protracted replication cycles, large genomes, complex virion structure and complicated nuclear and cytoplasmic replication events. In this review, we outline the 10 essential stages the virus must navigate to successfully complete replication. As each individual event along the replication continuum poses as a potential barrier for restriction, these essential checkpoints represent potential targets for antiviral development.

7.
Antibiotics (Basel) ; 11(11)2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36358189

ABSTRACT

Vibrio cholerae causes cholera and can switch between planktonic and biofilm lifeforms, where biofilm formation enhances transmission, virulence, and antibiotic resistance. Due to antibiotic microbial resistance, new antimicrobials including silver nanoparticles (AgNPs) are being studied. Nevertheless, little is known about the metabolic changes exerted by AgNPs on both microbial lifeforms. Our objective was to evaluate the changes in the metabolomic profile of V. cholerae planktonic and biofilm cells in response to sublethal concentrations of AgNPs using MS2 untargeted metabolomics and chemoinformatics. A total of 690 metabolites were quantified among all groups. More metabolites were significantly modulated in planktonic cells (n = 71) compared to biofilm (n = 37) by the treatment. The chemical class profiles were distinct for both planktonic and biofilm, suggesting a phenotype-dependent metabolic response to the nanoparticles. Chemical enrichment analysis showed altered abundances of oxidized fatty acids (FA), saturated FA, phosphatidic acids, and saturated stearic acid in planktonic cells treated with AgNPs, which hints at a turnover of the membrane. In contrast, no chemical classes were enriched in the biofilm. In conclusion, this study suggests that the response of V. cholerae to silver nanoparticles is phenotype-dependent and that planktonic cells experience a lipid remodeling process, possibly related to an adaptive mechanism involving the cell membrane.

8.
iScience ; 25(10): 105168, 2022 Oct 21.
Article in English | MEDLINE | ID: mdl-36204275

ABSTRACT

More than half the world's population is infected with human cytomegalovirus (HCMV), causing congenital birth defects and impacting the immuno-compromised. Many of the >170 HCMV genes remain uncharacterized, and this gap in knowledge limits the development of novel antivirals. In this study, we investigated the essential viral protein UL49 and found it displayed leaky late expression kinetics, and localized to nuclear replication compartments. Cells infected with mutant UL49 virus were unable to produce infectious virions and phenocopied other beta-gamma viral pre-initiation complex (vPIC) subunit (UL79, UL87, UL91, UL92, and UL95) mutant infections. RNA-seq analysis of vPIC mutant infections revealed a consistent diminution of genes encoding capsid subunits, including TRX2/UL85 and MCP/UL86, envelope glycoproteins gM, gL and gO, and egress-associated tegument proteins UL99 and UL103. Therefore, as a member of the vPIC, UL49 serves as a fundamental HCMV effector that governs viral gene transcription required to complete the replication cycle.

9.
Molecules ; 27(20)2022 Oct 18.
Article in English | MEDLINE | ID: mdl-36296609

ABSTRACT

The eggplant is a fruit rich in natural products and produced worldwide. However, its cultivation generates a large amount of scarcely used agricultural residues with poor chemical characterization. This study aimed to identify and quantify the metabolome and determine the composition of select phytochemicals and the overall antioxidant capacity of various anatomical parts of the plant. The plant's root, leaf, stem, and fruit were analyzed by quantitative mass spectrometry-based untargeted metabolomics and chemoinformatics, and phytochemicals were quantified by spectrophotometric analysis. Moreover, we determined the total antioxidant capacity of the distinct plant parts to infer a possible biological effect of the plant's metabolites. Various secondary metabolites were identified as terpenes, phenolic compounds, alkaloids, and saponins, distributed throughout the plant. The leaf and fruit presented the highest concentration of phenolic compounds, flavonoids, anthocyanins, and alkaloids, accompanied by the highest antioxidant capacity. Although the stem and root showed the lowest abundance of secondary metabolites, they provided around 20% of such compounds compared with the leaf and fruit. Overall, our study improved the understanding of the eggplant metabolome and concluded that the plant is rich in secondary metabolites, some with antioxidant properties, and shows potential nutraceutical and biopharmaceutical applications.


Subject(s)
Saponins , Solanum melongena , Solanum melongena/chemistry , Anthocyanins/chemistry , Antioxidants/chemistry , Chromatography, High Pressure Liquid , Phytochemicals/analysis , Fruit/chemistry , Phenols/chemistry , Flavonoids/analysis , Plant Extracts/chemistry , Metabolomics , Saponins/analysis , Terpenes/analysis
10.
Sci Rep ; 12(1): 12027, 2022 07 14.
Article in English | MEDLINE | ID: mdl-35835939

ABSTRACT

Coronary artery endothelial cells (CAEC) exert an important role in the development of cardiovascular disease. Dysfunction of CAEC is associated with cardiovascular disease in subjects with type 2 diabetes mellitus (T2DM). However, comprehensive studies of the effects that a diabetic environment exerts on this cellular type are scarce. The present study characterized the molecular perturbations occurring on cultured bovine CAEC subjected to a prolonged diabetic environment (high glucose and high insulin). Changes at the metabolite and peptide level were assessed by Liquid Chromatography-Mass Spectrometry (LC-MS2) and chemoinformatics. The results were integrated with published LC-MS2-based quantitative proteomics on the same in vitro model. Our findings were consistent with reports on other endothelial cell types and identified novel signatures of DNA/RNA, amino acid, peptide, and lipid metabolism in cells under a diabetic environment. Manual data inspection revealed disturbances on tryptophan catabolism and biosynthesis of phenylalanine-based, glutathione-based, and proline-based peptide metabolites. Fluorescence microscopy detected an increase in binucleation in cells under treatment that also occurred when human CAEC were used. This multi-omics study identified particular molecular perturbations in an induced diabetic environment that could help unravel the mechanisms underlying the development of cardiovascular disease in subjects with T2DM.


Subject(s)
Cardiovascular Diseases , Diabetes Mellitus, Type 2 , Amino Acids/metabolism , Animals , Cardiovascular Diseases/complications , Cattle , DNA/metabolism , Diabetes Mellitus, Type 2/metabolism , Endothelial Cells/metabolism , Humans , Lipid Metabolism , Peptides/metabolism , RNA/metabolism
11.
Int J Mol Sci ; 23(10)2022 May 21.
Article in English | MEDLINE | ID: mdl-35628580

ABSTRACT

Over 50% of the world's population is infected with Human Cytomegalovirus (HCMV). HCMV is responsible for serious complications in the immuno-compromised and is a leading cause of congenital birth defects. The molecular function of many HCMV proteins remains unknown, and a deeper understanding of the viral effectors that modulate virion maturation is required. In this study, we observed that UL34 is a viral protein expressed with leaky late kinetics that localises to the nucleus during infection. Deletion of UL34 from the HCMV genome (ΔUL34) did not abolish the spread of HCMV. Instead, over >100-fold fewer infectious virions were produced, so we report that UL34 is an augmenting gene. We found that ΔUL34 is dispensable for viral DNA replication, and its absence did not alter the expression of IE1, MCP, gB, UL26, UL83, or UL99 proteins. In addition, ΔUL34 infections were able to progress through the replication cycle to form a viral assembly compartment; however, virion maturation in the cytoplasm was abrogated. Further examination of the nucleus in ΔUL34 infections revealed replication compartments with aberrant morphology, containing significantly less assembled capsids, with almost none undergoing subsequent maturation. Therefore, this work lays the foundation for UL34 to be further investigated in the context of nuclear organization and capsid maturation during HCMV infection.


Subject(s)
Capsid , Cytomegalovirus , Capsid/metabolism , Capsid Proteins/genetics , Capsid Proteins/metabolism , Cytomegalovirus/genetics , Cytomegalovirus/metabolism , DNA Replication , DNA, Viral/metabolism , Humans , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Replication/genetics
12.
Toxins (Basel) ; 14(2)2022 02 08.
Article in English | MEDLINE | ID: mdl-35202151

ABSTRACT

Protein secretion is generally mediated by a series of distinct pathways in bacteria. Recently, evidence of a novel bacterial secretion pathway involving a bacteriophage-related protein has emerged. TcdE, a holin-like protein encoded by toxigenic isolates of Clostridioides difficile, mediates the release of the large clostridial glucosylating toxins (LCGTs), TcdA and TcdB, and TpeL from C. perfringens uses another holin-like protein, TpeE, for its secretion; however, it is not yet known if TcdE or TpeE secretion is specific to these proteins. It is also unknown if other members of the LCGT-producing clostridia, including Paeniclostridium sordellii (previously Clostridium sordellii), use a similar toxin-release mechanism. Here, we confirm that each of the LCGT-producing clostridia encode functional holin-like proteins in close proximity to the toxin genes. To characterise the respective roles of these holin-like proteins in the release of the LCGTs, P. sordellii and its lethal toxin, TcsL, were used as a model. Construction and analysis of mutants of the P. sordellii tcsE (holin-like) gene demonstrated that TcsE plays a significant role in TcsL release. Proteomic analysis of the secretome from the tcsE mutant confirmed that TcsE is required for efficient TcsL secretion. Unexpectedly, comparative sample analysis showed that TcsL was the only protein significantly altered in its release, suggesting that this holin-like protein has specifically evolved to function in the release of this important virulence factor. This specificity has, to our knowledge, not been previously shown and suggests that this protein may function as part of a specific mechanism for the release of all LCGTs.


Subject(s)
Bacterial Toxins/metabolism , Clostridium sordellii/metabolism , Animals , Bacterial Toxins/genetics , Chlorocebus aethiops , Clostridioides difficile/genetics , Clostridioides difficile/metabolism , Clostridium perfringens/genetics , Clostridium perfringens/metabolism , Clostridium sordellii/genetics , Vero Cells
13.
BMJ Open ; 11(4): e043944, 2021 04 21.
Article in English | MEDLINE | ID: mdl-33883150

ABSTRACT

OBJECTIVES: The objectives of this study were to estimate the direct and indirect excess costs of type 2 diabetes mellitus (T2D) using data representative for the German adult population and to investigate the association of sociodemographic and clinical determinants with these excess costs. SETTING: We calculated mean annual costs for individuals with T2D and a control group without diabetes, using data on healthcare utilisation and productivity losses from the cross-sectional German Health Interview and Examination Survey for Adults. We adjusted for group differences using entropy balancing and estimated excess costs for total, direct, indirect costs and additional cost categories using generalised linear models. We performed subgroup analyses to investigate the association of sociodemographic (age, sex and education) and clinical determinants (diabetes duration, glycaemic index and complications) with excess costs. PARTICIPANTS: The final study sample included n=325 individuals with T2D and n=4490 individuals without diabetes in the age between 18 and 79 years. RESULTS: Total excess costs amounted to €927, of which €719 were attributable to direct and €209 to indirect excess costs. Total costs were significantly increased by 28% for T2D compared with controls. Group differences in direct, outpatient and medication costs were statistically significant. Medication costs were 88% higher for T2D and had the highest share in direct excess costs. With respect to specific determinants, direct excess costs ranged from €203 for 4-10 years diabetes duration to €1405 for diabetes complications. Indirect excess costs ranged from €-544 for >10 years diabetes duration to €995 for high education. CONCLUSIONS: T2D was associated with high costs, mainly due to direct costs. As pointed out by our results, diabetes complications and comorbidities have a large impact on the costs, leaving medication costs as main contributor of T2D excess costs.


Subject(s)
Diabetes Complications , Diabetes Mellitus, Type 2 , Adolescent , Adult , Aged , Cost of Illness , Cross-Sectional Studies , Diabetes Mellitus, Type 2/epidemiology , Health Care Costs , Humans , Middle Aged , Young Adult
14.
Elife ; 92020 09 10.
Article in English | MEDLINE | ID: mdl-32910773

ABSTRACT

Human Cytomegalovirus (HCMV) infects over half the world's population, is a leading cause of congenital birth defects, and poses serious risks for immuno-compromised individuals. To expand the molecular knowledge governing virion maturation, we analysed HCMV virions using proteomics, and identified a significant proportion of host exosome constituents. To validate this acquisition, we characterized exosomes released from uninfected cells, and demonstrated that over 99% of the protein cargo was subsequently incorporated into HCMV virions during infection. This suggested a common membrane origin, and utilization of host exosome machinery for virion assembly and egress. Thus, we selected a panel of exosome proteins for knock down, and confirmed that loss of 7/9 caused significantly less HCMV production. Saliently, we report that VAMP3 is essential for viral trafficking and release of infectious progeny, in various HCMV strains and cell types. Therefore, we establish that the host exosome pathway is intrinsic for HCMV maturation, and reveal new host regulators involved in viral trafficking, virion envelopment, and release. Our findings underpin future investigation of host exosome proteins as important modulators of HCMV replication with antiviral potential.


Subject(s)
Cytomegalovirus/physiology , Exosomes/metabolism , Host-Pathogen Interactions , Virus Assembly , Virus Release , Cell Line , Exosomes/genetics , Humans , Protein Transport , Proteomics , Vesicle-Associated Membrane Protein 3/genetics , Viral Proteins/metabolism , Virion/physiology , Virus Replication
15.
Z Gerontol Geriatr ; 52(1): 3-9, 2019 Feb.
Article in German | MEDLINE | ID: mdl-28332012

ABSTRACT

BACKGROUND: Among the elderly falls frequently result in injuries, increase the need for long-term care and pose a challenge for the quality assurance in nursing care. We describe the frequency and risk factors of falls among care-dependent persons using home care services in Germany. METHODS: The participants of the study "Nursing-related health problems in home care" (n = 880) were recruited based on a list of the officially accredited nursing services. Data collection followed a standardized study protocol. Proportions were calculated and adjusted odds ratios and predicted probabilities were estimated using binary logistic regression. RESULTS: Falls are a frequent occurrence among care-dependent persons who are cared for by home care services: Almost every tenth care-dependent person suffers from a fall within a period of 2 weeks. Falls are mainly associated with social and care-related factors. Besides a low educational status this comprises certain living and care arrangements: People living alone or having infrequent contact to their nursing service as well as clients that, according to their carers, should receive more support have a significantly higher chance of falling. Multimorbidity is a medical risk factor while neurological diseases as well as polypharmacy present increased risks only in interaction with living and care arrangements. CONCLUSION: Nursing staff and physicians should maintain an overview of the social and health conditions of people in need of long-term care. If care-dependent persons live alone or are infrequently cared for, additional medical problems considerably increase the risk for falling; therefore, preventive interventions and follow-up assessments of actual need levels should be promptly considered if health conditions or living arrangements change.


Subject(s)
Accidental Falls , Home Care Services , Accidental Falls/prevention & control , Accidental Falls/statistics & numerical data , Aged , Germany , Humans , Long-Term Care , Risk Factors
16.
Neural Dev ; 13(1): 22, 2018 09 15.
Article in English | MEDLINE | ID: mdl-30219101

ABSTRACT

BACKGROUND: Proper patterning of dendritic and axonal arbors is a critical step in the formation of functional neuronal circuits. Developing circuits rely on an array of molecular cues to shape arbor morphology, but the underlying mechanisms guiding the structural formation and interconnectivity of pre- and postsynaptic arbors in real time remain unclear. Here we explore how Down syndrome cell adhesion molecule (DSCAM) differentially shapes the dendritic morphology of central neurons and their presynaptic retinal ganglion cell (RGC) axons in the developing vertebrate visual system. METHODS: The cell-autonomous role of DSCAM, in tectal neurons and in RGCs, was examined using targeted single-cell knockdown and overexpression approaches in developing Xenopus laevis tadpoles. Axonal arbors of RGCs and dendritic arbors of tectal neurons were visualized using real-time in vivo confocal microscopy imaging over the course of 3 days. RESULTS: In the Xenopus visual system, DSCAM immunoreactivity is present in RGCs, cells in the optic tectum and the tectal neuropil at the time retinotectal synaptic connections are made. Downregulating DSCAM in tectal neurons significantly increased dendritic growth and branching rates while inducing dendrites to take on tortuous paths. Overexpression of DSCAM, in contrast, reduced dendritic branching and growth rate. Functional deficits mediated by tectal DSCAM knockdown were examined using visually guided behavioral assays in swimming tadpoles, revealing irregular behavioral responses to visual stimulus. Functional deficits in visual behavior also corresponded with changes in VGLUT/VGAT expression, markers of excitatory and inhibitory transmission, in the tectum. Conversely, single-cell DSCAM knockdown in the retina revealed that RGC axon arborization at the target is influenced by DSCAM, where axons grew at a slower rate and remained relatively simple. In the retina, dendritic arbors of RGCs were not affected by the reduction of DSCAM expression. CONCLUSIONS: Together, our observations implicate DSCAM in the control of both pre- and postsynaptic structural and functional connectivity in the developing retinotectal circuit, where it primarily acts as a neuronal brake to limit and guide postsynaptic dendrite growth of tectal neurons while it also facilitates arborization of presynaptic RGC axons cell autonomously.


Subject(s)
Cell Adhesion Molecules/metabolism , Gene Expression Regulation, Developmental/physiology , Neurons/cytology , Synapses/metabolism , Visual Pathways/cytology , Visual Pathways/growth & development , Xenopus Proteins/metabolism , Animals , Avoidance Learning/physiology , Axons/metabolism , Cell Adhesion Molecules/genetics , Dendrites/metabolism , Down-Regulation/drug effects , Down-Regulation/physiology , Image Processing, Computer-Assisted , Microscopy, Confocal , Morpholinos/genetics , Morpholinos/metabolism , Morpholinos/pharmacology , Neurons/metabolism , Photic Stimulation/adverse effects , Retina/cytology , Retina/growth & development , Superior Colliculi/cytology , Superior Colliculi/growth & development , Synapses/drug effects , Transfection , Vesicular Glutamate Transport Proteins/metabolism , Vesicular Inhibitory Amino Acid Transport Proteins/metabolism , Xenopus Proteins/genetics , Xenopus laevis
17.
Psychol Med ; 48(9): 1484-1493, 2018 07.
Article in English | MEDLINE | ID: mdl-29094658

ABSTRACT

BACKGROUND: Whilst preterm-born individuals have an increased risk of developing attention-deficit/hyperactivity disorder (ADHD), and are reported to have ADHD-like attention and arousal impairments, direct group comparisons are scarce. METHODS: We directly compared preterm-born adolescents (n = 186) to term-born adolescents with ADHD (n = 69), and term-born controls (n = 135), aged 11-23, on cognitive-performance, event-related potential and skin conductance level (SCL) measures associated with attention and arousal. The measures are from baseline and fast-incentive conditions of a four-choice reaction time task, previously shown to discriminate between the individuals with ADHD and controls. We aimed to establish whether preterm-born adolescents show: (a) identical cognitive-neurophysiological impairments to term-born adolescents with ADHD (b) possible additional impairments, and whether (c) the observed impairments correlate with ADHD symptom scores. RESULTS: The preterm group, like the term-born ADHD group, showed increased mean reaction time (MRT) and reaction time variability (RTV) in the baseline condition, and attenuated contingent negative variation (CNV) amplitude (response preparation) in the fast-incentive condition. The preterm group, only, did not show significant within-group adjustments in P3 amplitude (attention allocation) and SCL (peripheral arousal). Dimensional analyses showed that ADHD symptoms scores correlated significantly with MRT, RTV and CNV amplitude only. CONCLUSIONS: We find impairments in cognition and brain function in preterm-born adolescents that are linked to increased ADHD symptoms, as well as further impairments, in lack of malleability in neurophysiological processes. Our findings indicate that such impairments extend at least to adolescence. Future studies should extend these investigations into adulthood.


Subject(s)
Arousal , Attention Deficit Disorder with Hyperactivity/physiopathology , Attention , Cognitive Dysfunction/physiopathology , Infant, Premature , Adolescent , Child , Contingent Negative Variation , Electroencephalography , England , Female , Humans , Male , Premature Birth , Psychomotor Performance , Reaction Time , Regression Analysis , Young Adult
18.
Semin Cell Dev Biol ; 67: 91-100, 2017 07.
Article in English | MEDLINE | ID: mdl-28456604

ABSTRACT

Herpesviruses are remarkable pathogens possessing elaborate mechanisms to seize various host cellular components for immune evasion, replication, and virion egress. As viruses are dependent upon their hosts, investigating this intricate interplay has revealed that the exosome pathway is utilised by alpha (Herpes Simplex Virus 1), beta (Human Cytomegalovirus, and Human Herpesvirus 6) and gamma (Epstein-Barr Virus, and Kaposi Sarcoma-associated Herpesvirus) herpesviruses. Virions and exosomes share similar properties and functions. For example, exosomes are small membranous nanovesicles (30-150nm) released from cells that contain proteins, DNA, and various coding and non-coding RNA species. Given exosomes can shuttle various molecular cargo from a donor to recipient cell, they serve as important vehicles facilitating cell-cell communication. Therefore, exploitation by herpesviruses impacts several aspects of infection including: i) acquisition of molecular machinery for secondary envelopment and viral assembly, ii) export of immune-related host proteins from infected cells, iii) enhancing infection in surrounding cells via transfer of viral proteins, mRNA and miRNA, and iv) regulation of viral protein expression to promote persistence. Studying the dichotomy that exists between host exosomes and herpesviruses has two benefits. Firstly, it will reveal the precise pathogenic mechanisms viruses have evolved, generating knowledge for antiviral development. Secondly, it will shed light upon fundamental exosome characteristics that remain unknown, including cargo selection, protein trafficking, and non-canonical biogenesis.


Subject(s)
Exosomes/virology , Gene Expression Regulation, Viral , Herpesviridae Infections/immunology , Herpesviridae/pathogenicity , Viral Proteins/genetics , Virion/pathogenicity , Animals , Dendritic Cells/immunology , Dendritic Cells/virology , Exosomes/immunology , Herpesviridae/genetics , Herpesviridae/growth & development , Herpesviridae Infections/pathology , Herpesviridae Infections/virology , Humans , Immune Evasion , Lymphocytes/immunology , Lymphocytes/virology , MicroRNAs/genetics , MicroRNAs/metabolism , Protein Transport , RNA, Messenger/genetics , RNA, Messenger/metabolism , Signal Transduction , Viral Proteins/metabolism , Virion/genetics , Virion/growth & development
19.
Matrix Biol ; 59: 39-53, 2017 05.
Article in English | MEDLINE | ID: mdl-27425255

ABSTRACT

Advanced glycation endproducts (AGEs) are a heterogeneous group of compounds that form via non-enzymatic glycation of proteins throughout our lifespan and at a higher rate in certain chronic diseases such as diabetes. AGEs contribute to the progression of fibrosis, in part by stimulating cellular pathways that affect gene expression. Long-lived ECM proteins are targets for non-enzymatic glycation but the question of whether the AGE-modified ECM leads to excess ECM accumulation and fibrosis remains unanswered. In this study, cellular changes due to AGE accretion in the ECM were investigated. Non-enzymatic glycation of proteins in a decellularized fibroblast ECM was achieved by incubating the ECM in a solution of methylglyoxal (MGO). Mass spectrometry of fibronectin (FN) isolated from the glycated matrix identified twenty-eight previously unidentified MGO-derived AGE modification sites including functional sites such as the RGD integrin-binding sequence. Mesangial cells grown on the glycated, decellularized matrix assembled increased amounts of FN matrix. Soluble AGE-modified bovine serum albumin (BSA) also stimulated FN matrix assembly and this effect was reduced by function-blocking antibodies against the receptor for AGE (RAGE). These results indicate that cells respond to AGEs by increasing matrix assembly and that RAGE is involved in this response. This raises the possibility that the accumulation of ECM during the progression of fibrosis may be enhanced by cell interactions with AGEs on a glycated ECM.


Subject(s)
Extracellular Matrix/drug effects , Fibronectins/agonists , Glycation End Products, Advanced/pharmacology , Mesangial Cells/drug effects , Receptor for Advanced Glycation End Products/metabolism , Serum Albumin, Bovine/pharmacology , Amino Acid Sequence , Animals , Antibodies, Neutralizing/pharmacology , Cattle , Cell Line, Transformed , Extracellular Matrix/chemistry , Extracellular Matrix/metabolism , Fibronectins/chemistry , Fibronectins/genetics , Fibronectins/metabolism , Fibrosis , Gene Expression , Humans , Integrins/genetics , Integrins/metabolism , Mesangial Cells/metabolism , Mesangial Cells/pathology , Mice , Models, Biological , NIH 3T3 Cells , Oligopeptides/genetics , Oligopeptides/metabolism , Pyruvaldehyde/chemistry , Pyruvaldehyde/pharmacology , Rats , Receptor for Advanced Glycation End Products/antagonists & inhibitors , Receptor for Advanced Glycation End Products/genetics , Signal Transduction
20.
Gesundheitswesen ; 79(3): 164-173, 2017 Mar.
Article in German | MEDLINE | ID: mdl-27056714

ABSTRACT

Aim of the study: The use of physical therapy in German children and adolescents has so far solely been analyzed on the basis of health insurance data, which can neither consider case history nor social factors. Using the KiGGS-baseline survey it is possible to examine the use of physical therapy on the basis of parental reported health problems and social factors. Methodology: Identifiable determinants for the use of physical therapy in the last 12 months in the KiGGS-baseline survey were examined bivariate and multivariate in logistic regression models with mutual adjustment. The following determinants were considered: social factors, somatic disorders and psychological abnormalities. The proportion of the use of physical therapy, which can be explained by these determinants, was estimated using population-attributable risk fraction. Results: The frequency of the use of physical therapy in the last 12 months in the 0 to 17-year-olds in the KiGGS-baseline survey was 6,4% with higher use during infancy and adolescence. The socio-economic status of parents was not associated with the use of physical therapy. A migration background decreased the probability of the use of physical therapy, for example, among children aged 0 to 2 years (ORadjusted: 0,5 [95% CI: 0,2-1,0]). In those with scoliosis, the use of physical therapy was almost twice as frequent in infancy as in adolescence (58,4 vs. 34,4%). A maximum of 15% of all children and adolescents with back pain reported the use of physical therapy. When ADHD was diagnosed at preschool age, the probability of using physical therapy was increased (ORadjusted: 5,1 [95% CI: 1,4-18,6]). The health problems, which were assessed in the KiGGS-baseline survey and considered for this analysis could explain 37% of the use of physical therapy in the 0 to 2-year-olds. In the other age groups, 59 to 62% could be explained. Conclusion: Comparison of the KiGGS-baseline survey with health insurance data shows similar frequencies and patterns of the use of physical therapy and can therefore be used for the analysis of healthcare questions on the use of physical therapy. The data point to potential deficits in treatment in population segments and for some conditions. An examination of these hypotheses based on analyses of health insurance data seems to be reasonable.


Subject(s)
Disabled Persons/rehabilitation , Health Care Costs/statistics & numerical data , National Health Programs/economics , National Health Programs/statistics & numerical data , Physical Therapy Modalities/statistics & numerical data , Utilization Review , Adolescent , Adolescent Health/statistics & numerical data , Age Distribution , Child , Child Health/statistics & numerical data , Child, Preschool , Female , Germany/epidemiology , Health Care Surveys , Humans , Infant , Infant, Newborn , Male , Prescriptions/statistics & numerical data , Sex Distribution , Young Adult
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