ABSTRACT
Introduction: In mammals, sn-1-diacylglycerol lipases (DAGL) generate 2-arachidonoylglycerol (2-AG) that, as the major endocannabinoid, modulates synaptic neurotransmission by acting on CB1 cannabinoid receptors (CB1R). Even though the insect genome codes for inaE, which is a DAGL ortholog (dDAGL), its products and their functions remain unknown particularly because insects lack chordate-type cannabinoid receptors. Materials and Methods: Gain-of-function and loss-of-function genetic manipulations were carried out in Drosophila melanogaster, including the generation of both dDAGL-deficient and mammalian CB1R-overexpressing flies. Neuroanatomy, dietary manipulations coupled with targeted mass spectrometry determination of arachidonic acid and 2-linoleoyl glycerol (2-LG) production, behavioral assays, and signal transduction profiling for Akt and Erk kinases were employed. Findings from Drosophilae were validated by a CB1R-binding assay for 2-LG in mammalian cortical homogenates with functionality confirmed in neurons using high-throughput real-time imaging in vitro. Results: In this study, we show that dDAGL is primarily expressed in the brain and nerve cord of Drosophila during larval development and in adult with 2-LG being its chief product as defined by dietary precursor availability. Overexpression of the human CB1R in the ventral nerve cord compromised the mobility of adult Drosophilae. The causality of 2-LG signaling to CB1R-induced behavioral impairments was shown by inaE inactivation normalizing defunct motor coordination. The 2-LG-induced activation of transgenic CB1Rs affected both Akt and Erk kinase cascades by paradoxical signaling. Data from Drosophila models were substantiated by showing 2-LG-mediated displacement of [3H]CP 55,940 in mouse cortical homogenates and reduced neurite extension and growth cone collapsing responses in cultured mouse neurons. Conclusions: Overall, these results suggest that 2-LG is an endocannabinoid-like signal lipid produced by dDAGL in Drosophila.
Subject(s)
Drosophila melanogaster , Lipoprotein Lipase , Animals , Drosophila melanogaster/genetics , Gain of Function Mutation , Glycerol , Lipoprotein Lipase/genetics , Mice , Receptors, Cannabinoid , Signal Transduction/geneticsABSTRACT
This research deals with the presence of depressive symptoms in adolescents aged 11-17 years at the Salesian College "Rosenthal de la Puente" of Magdalena del Mar, Lima, Peru, during the month of March 2016. Method: This is an observational, descriptive, and with a prospective cross- sectional design, the instrument used was the Children's Depression Inventory (CDI) and also on the same tab where inventory was personal data were recorded. Study Population and Sample: sample chosen for convenience, and is made up of 320 students (267 male adolescents and 53 adolescent women). Results: 79.375 per cent of depressive symptoms was found. For grades of 20.62 per cent depressive symptoms one no depressive symptoms; 25.63 per cent of the total one with mild depressive symptoms; 26.25 per cent one with moderate symptoms and severe symptoms 27.50 per cent. Objective: Main Objective: To determine the presence of depressive symptoms in high school students of a college of Magdalena Sea in the month of March 2016. Specific objectives: Determine the level of depressive symptoms present in the adolescent population. Identify the distribution by age and sex of depressive symptoms.
La presente investigación trata sobre la presencia de síntomas depresivos en adolescentes de 11 a 17 años en el colegio salesiano "Rosenthal de la Puente" del distrito de Magdalena del Mar, en Lima, Perú, durante el mes de Marzo del año 2016. Método: Es un estudio de tipo observacional, descriptivo, y con un diseño transversal prospectivo, el instrumento que se utilizó fue el Children's Depression Inventory (CDI) y se consignaron los datos personales. Población de Estudio y Muestra: muestra elegida por conveniencia, y conformada por 320 alumnos (267 adolescentes varones y 53 adolescentes mujeres) Resultados: Se encontró un 79.375 por ciento de sintomatología depresiva. En cuanto a los grados de sintomatología depresiva un 20.62 por ciento no presenta sintomatología depresiva; un 25.63 por ciento del total presentan sintomatología depresiva leve; un 26.25 por ciento presentan sintomatología moderada y un 27.50 por ciento sintomatología severa. Objetivos: Objetivo Principal: Determinar la presencia de síntomas depresivos en alumnos de secundaria de un colegio de Magdalena del mar en el mes de Marzo del año 2016. Objetivos específicos: Determinar el grado de los síntomas depresivos presentes en la población de adolescentes. Identificar la distribución por edad y sexo de los síntomas depresivos.
Subject(s)
Male , Female , Humans , Adolescent , Symptom Assessment , Depression/diagnosis , Psychology, Adolescent , Observational Studies as Topic , Prospective Studies , Cross-Sectional StudiesABSTRACT
L1- and NCAM-type cell adhesion molecules represent distinct protein families that function as specific receptors for different axon guidance cues. However, both L1 and NCAM proteins promote axonal growth by inducing neuronal tyrosine kinase activity and are coexpressed in subsets of axon tracts in arthropods and vertebrates. We have studied the functional requirements for the Drosophila L1- and NCAM-type proteins, Neuroglian (Nrg) and Fasciclin II (FasII), during postembryonic sensory axon guidance. The rescue of the Neuroglian loss-of-function (LOF) phenotype by transgenically expressed L1- and NCAM-type proteins demonstrates a functional interchangeability between these proteins in Drosophila photoreceptor pioneer axons, where both proteins are normally coexpressed. In contrast, the ectopic expression of Fasciclin II in mechanosensory neurons causes a strong enhancement of the axonal misguidance phenotype. Moreover, our findings demonstrate that this functionally redundant specificity to mediate axon guidance has been conserved in their vertebrate homologs, L1-CAM and NCAM.
Subject(s)
Cell Adhesion Molecules, Neuronal/genetics , Drosophila/embryology , Growth Cones/metabolism , Nervous System/embryology , Neurons, Afferent/metabolism , Animals , Cell Adhesion Molecules, Neuronal/metabolism , Cell Communication/genetics , Drosophila/genetics , Drosophila/metabolism , Drosophila Proteins , Eye/cytology , Eye/embryology , Eye/metabolism , Gene Expression Regulation, Developmental/genetics , Growth Cones/ultrastructure , Mechanoreceptors/cytology , Mechanoreceptors/embryology , Mechanoreceptors/metabolism , Nervous System/cytology , Nervous System/metabolism , Neural Cell Adhesion Molecule L1/genetics , Neural Cell Adhesion Molecule L1/metabolism , Neural Cell Adhesion Molecules/genetics , Neural Cell Adhesion Molecules/metabolism , Neurons, Afferent/cytology , Phenotype , Photoreceptor Cells, Invertebrate/cytology , Photoreceptor Cells, Invertebrate/embryology , Photoreceptor Cells, Invertebrate/metabolism , Transgenes/genetics , Wings, Animal/cytology , Wings, Animal/embryologyABSTRACT
To further investigate the role of the Drosophila cell adhesion molecules (CAMs), we have developed an in vitro assay that allows us to test the contribution individual CAMs make to promote outgrowth of specific Drosophila neurons. The extension of primary cultured neurons on a substrate of purified recombinant CAM is measured. We show that both FasciclinII and Neuroglian are able to promote outgrowth of FasciclinII or Neuroglian expressing neurons, respectively. Furthermore, this growth promotion activity is provided when the CAMs are presented both in a substrate bound or soluble form. We also show that the signal provided by the CAMs acts via the Heartless fibroblast growth factor receptor (FGFR) as outgrowth is reduced to basal levels in the presence of an FGFR inhibitor or if Heartless function is missing from the neurons.
Subject(s)
Cell Adhesion Molecules, Neuronal/metabolism , Cell Differentiation/physiology , Drosophila Proteins/physiology , Nervous System/embryology , Neurites/metabolism , Protein-Tyrosine Kinases/physiology , Receptors, Fibroblast Growth Factor/physiology , Animals , Biological Assay/methods , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cell Adhesion Molecules, Neuronal/pharmacology , Cell Differentiation/drug effects , Cells, Cultured , Drosophila Proteins/antagonists & inhibitors , Drosophila Proteins/genetics , Drosophila melanogaster , Humans , Molecular Sequence Data , Nervous System/cytology , Nervous System/metabolism , Neurites/drug effects , Neurites/ultrastructure , Phylogeny , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/genetics , Pyrimidines/pharmacology , Receptors, Fibroblast Growth Factor/antagonists & inhibitors , Receptors, Fibroblast Growth Factor/genetics , Sequence Homology, Nucleic Acid , Signal Transduction/physiologyABSTRACT
Neural cell adhesion molecules (CAMs) are important players during neurogenesis and neurite outgrowth as well as axonal fasciculation and pathfinding. Some of these developmental processes entail the activation of cellular signaling cascades. Pharmacological and genetic evidence indicates that the neurite outgrowth-promoting activity of L1-type CAMs is at least in part mediated by the stimulation of neuronal receptor tyrosine kinases (RTKs), especially FGF and EGF receptors. It has long been suspected that neural CAMs might physically interact with RTKs, but their activation by specific cell adhesion events has not been directly demonstrated. Here we report that gain-of-function conditions of the Drosophila L1-type CAM Neuroglian result in profound sensory axon pathfinding defects in the developing Drosophila wing. This phenotype can be suppressed by decreasing the normal gene dosage of the Drosophila EGF receptor gene. Furthermore, in Drosophila S2 cells, cell adhesion mediated by human L1-CAM results in the specific activation of human EGF tyrosine kinase at cell contact sites and EGF receptors engage in a physical interaction with L1-CAM molecules. Thus L1-type CAMs are able to promote the adhesion-dependent activation of EGF receptor signaling in vitro and in vivo.
