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1.
Tissue Cell ; 39(2): 123-30, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17376496

RESUMEN

Retinoic acid is known to induce vertebrate stem cells to differentiate into a variety of cell types, including neurons. Although retinoic acid was reported to affect morphogenetic pattern specification in the hydrozoan Hydractinia (Müller, W.A., 1984. Retinoids and pattern formation in a hydroid. J. Embryol. Exp. Morph. 81, 253-271) and a retinoid RXR receptor was cloned in the jellyfish Tripedalia (Kostrouch, Z., Kostrouchova, M., Love, W., Jannini, E., Piatigorsky, J., Rall, J.E., 1998. Retinoic acid X receptor in the diploblast, Tripedalia cystophora. Proc. Natl. Acad. Sci. U.S.A. 95, 13442-13447), the cellular targets of retinoids were not investigated. We used Western immunoblotting and immunohistochemistry to investigate the presence and cellular distribution of a RXR-like receptor in the sea pansy Renilla koellikeri and in the staghorn coral Acropora millepora (Cnidaria, Anthozoa). Western blots revealed a 64 kDa protein from a sea pansy extract in a band that co-migrated with a RXR protein from the rat brain. Using antibodies raised against an epitope of human alpha RXR, we visualized putative ectodermal sensory cells in the polyp column of the adult sea pansy. Immunoreactivity was absent in staghorn coral larvae but present in the polyp column of adult colonies in the form of clusters of neuron-like cells in the basiectoderm near the ectoderm-mesoglea interface. These observations suggest that a RXR-like receptor is involved in epithelial nerve cell specification in adult anthozoans and that this role is conserved throughout evolution.


Asunto(s)
Antozoos/metabolismo , Neuronas/metabolismo , Receptores de Ácido Retinoico/metabolismo , Renilla/metabolismo , Animales , Western Blotting , Inmunohistoquímica , Neuronas/inmunología , Transporte de Proteínas , Ratas , Receptores de Ácido Retinoico/inmunología
2.
J Neurosci ; 22(9): RC220, 2002 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-11978861

RESUMEN

Transforming growth factor beta1 (TGF-beta1) induces long-term synaptic facilitation and long-term increases in excitability in Aplysia. Here we report that this growth factor has acute effects as well. Treatment of pleural-pedal ganglia with TGF-beta1 for 5 min activated mitogen-activated protein kinase (MAPK) and stimulated the phosphorylation of synapsin in a MAPK-dependent manner. This phosphorylation appeared to modulate synapsin distribution in cultured sensory neurons. Control neurons exhibited a punctate distribution of synapsin along neurites, which appeared to represent high concentration aggregates of synapsin. TGF-beta1-treated sensory neurons showed a significant reduction in the number of these puncta, an effect that was blocked by the MAP/ERK kinase inhibitor U0126. The functional consequence of TGF-beta1 was tested by examining its effects on synaptic transmission at the sensorimotor synapse. Application of TGF-beta1 reduced the magnitude of synaptic depression. This effect was dependent on MAPK, consistent with the hypothesis that TGF-1 mobilizes synaptic vesicles through the phosphorylation of synapsin.


Asunto(s)
Inhibición Neural/efectos de los fármacos , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo , Sinapsinas/metabolismo , Transmisión Sináptica/efectos de los fármacos , Factor de Crecimiento Transformador beta/farmacología , Animales , Aplysia , Butadienos/farmacología , Células Cultivadas , Estimulación Eléctrica , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Potenciales Postsinápticos Excitadores/fisiología , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/efectos de los fármacos , Ganglios de Invertebrados/metabolismo , Técnicas In Vitro , Sustancias Macromoleculares , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neuronas Motoras/citología , Neuronas Motoras/efectos de los fármacos , Neuronas Motoras/fisiología , Inhibición Neural/fisiología , Neuritas/metabolismo , Neuronas Aferentes/citología , Neuronas Aferentes/efectos de los fármacos , Neuronas Aferentes/metabolismo , Nitrilos/farmacología , Fosforilación/efectos de los fármacos , Transmisión Sináptica/fisiología , Vesículas Sinápticas/metabolismo , Factor de Crecimiento Transformador beta1
3.
J Biol Chem ; 276(31): 28913-9, 2001 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-11384986

RESUMEN

The endophilin family of proteins function in clathrin-mediated endocytosis. Here, we have identified and cloned the rat germinal center kinase-like kinase (rGLK), a member of the GCK (germinal center kinase) family of c-Jun N-terminal kinase (JNK) activating enzymes, as a novel endophilin I-binding partner. The interaction occurs both in vitro and in cells and is mediated by the Src homology 3 domain of endophilin I and a region of rGLK containing the endophilin consensus-binding sequence PPRPPPPR. Overlay analysis of rat brain extracts demonstrates that endophilin I is a major Src homology 3 domain-binding partner for rGLK. Overexpression of full-length endophilin I activates rGLK-mediated JNK activation, whereas N- and C-terminal fragments of endophilin I block JNK activation. Thus, endophilin I appears to have a novel function in JNK activation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Encéfalo/metabolismo , Secuencia de Consenso , Activación Enzimática , Biblioteca de Genes , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos , Datos de Secuencia Molecular , Proteínas Serina-Treonina Quinasas/química , Ratas , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Dominios Homologos src
4.
Comp Biochem Physiol B Biochem Mol Biol ; 126(3): 435-43, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11007186

RESUMEN

The L2-4,6 and L5 cells located in the left upper quadrant of the abdominal ganglion of Aplysia californica express the L5-67 and LUQ-1 genes, respectively, in a nonoverlapping manner. These cells send major neurites to the kidney and at least some of them were shown to innervate the renal pore closer muscle, and thereby control its function. By using in-situ hybridization and immunofluorescence, the presence of L5-67 and LUQ-1 mRNAs and peptides was studied in the kidney, with emphasis on the region of the renal pore. We detected immunoreactive materials in many small varicose nerve fibers running along the central epithelium in the inner parts of the kidney, and in neurites located within a large nerve associated with muscles inside the renal pore. Our observations represent the first direct evidence of the presence of gene products from LUQ cells at the renal pore, suggesting that they may be responsible for mediating LUQ cell signals. Furthermore, mRNAs coding for the L5-67 and LUQ-1 peptides were also found in the nerve structure inside the renal pore. Our report documents a striking example of neuropeptide mRNA targeting nerve terminals that are very distant from their cell bodies.


Asunto(s)
Aplysia/fisiología , Ganglios/fisiología , Regulación de la Expresión Génica/fisiología , Animales , ADN Complementario/análisis , ADN Complementario/genética , Técnica del Anticuerpo Fluorescente , Neuronas/fisiología
5.
Learn Mem ; 6(3): 317-30, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10492013

RESUMEN

Exogenous recombinant human transforming growth factor beta-1 (TGF-beta1) induced long-term facilitation of Aplysia sensory-motor synapses. In addition, 5-HT-induced facilitation was blocked by application of a soluble fragment of the extracellular portion of the TGF-beta1 type II receptor (TbetaR-II), which presumably acted by scavenging an endogenous TGF-beta1-like molecule. Because TbetaR-II is essential for transmembrane signaling by TGF-beta, we sought to determine whether Aplysia tissues contained TbetaR-II and specifically, whether neurons expressed the receptor. Western blot analysis of Aplysia tissue extracts demonstrated the presence of a TbetaR-II-immunoreactive protein in several tissue types. The expression and distribution of TbetaR-II-immunoreactive proteins in the central nervous system was examined by immunohistochemistry to elucidate sites that may be responsive to TGF-beta1 and thus may play a role in synaptic plasticity. Sensory neurons in the ventral-caudal cluster of the pleural ganglion were immunoreactive for TbetaR-II, as well as many neurons in the pedal, abdominal, buccal, and cerebral ganglia. Sensory neurons cultured in isolation and cocultured sensory and motor neurons were also immunoreactive. TGF-beta1 affected the biophysical properties of cultured sensory neurons, inducing an increase of excitability that persisted for at least 48 hr. Furthermore, exposure to TGF-beta1 resulted in a reduction in the firing threshold of sensory neurons. These results provide further support for the hypothesis that TGF-beta1 plays a role in long-term synaptic plasticity in Aplysia.


Asunto(s)
Aplysia/fisiología , Neuronas Aferentes/fisiología , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Factor de Crecimiento Transformador beta/fisiología , Animales , Western Blotting , Células Cultivadas , Electroforesis en Gel de Poliacrilamida , Electrofisiología , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/metabolismo , Inmunohistoquímica , Membranas/metabolismo , Neuronas Aferentes/metabolismo , Factor de Crecimiento Transformador beta/metabolismo
6.
J Neurosci ; 18(15): 5586-93, 1998 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-9671650

RESUMEN

Serotonin (5-HT) is involved in the control of various behaviors in Aplysia californica, including reproduction, feeding, locomotion, circadian rhythm, synaptic plasticity, and synaptic growth. The large variety of functions of 5-HT is mediated by different receptor subtypes that are coupled to different second-messenger systems. Here, we report the cloning of a cDNA coding for an Aplysia G-protein-coupled 5-HT receptor (5-HTap1). Its deduced amino acid sequence resembles those of the 5-HT1 receptor subfamily. When expressed in stable cell lines, 5-HTap1 exhibits high-affinity binding for the serotonergic radioligand [N-methyl-3H]lysergic acid diethylamide. This binding is competed by several 5-HT agonists and antagonists, and the pharmacological profile of inhibition has some similarities with those of 5-HT1 and 5-HT7 receptors. Application of 5-HT or its agonists 5-carboxamidotryptamine maleate and (+/-)-8-hydroxy-2-(di-n-propyl-amino) tetralin hydrobromide on cells transformed with 5-HTap1 produced a dose-dependent inhibition of forskolin-stimulated cAMP accumulation. 5-HTap1 is thus negatively coupled to adenylate cyclase. The production of antiserum against the 5-HTap1 receptor allowed us to examine its expression in animal tissues. The receptor protein is detected in every tissue examined, although it seems only weakly expressed in some samples. The receptor is also found in every ganglia of the nervous system, both in the sheath and in the neurons. 5-HTap1 mRNA is absent from the sheath, indicating that the protein observed there is probably located on the nerve terminals.


Asunto(s)
Adenilil Ciclasas/metabolismo , Aplysia/metabolismo , ADN Complementario/genética , Receptores de Serotonina/metabolismo , Inhibidores de Adenilato Ciclasa , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Unión Competitiva , Clonación Molecular , Inhibidores Enzimáticos/farmacología , Código Genético , Datos de Secuencia Molecular , Filogenia , Agonistas de Receptores de Serotonina/farmacología
7.
Gene ; 208(2): 271-7, 1998 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-9524280

RESUMEN

The L5-67 gene was first identified on the basis of its high expression level in the LUQ neurons, a group of four giant cells located in the left upper quadrant of the abdominal ganglion of Aplysia californica. Its mRNA and peptides were later shown to be present in these cells, as well as in about 100 other smaller neurons in the CNS. L5-67 propeptide and/or mature peptides are also present in peripheral organs, particularly in the kidney, which is the target of most LUQ processes. Using RT-PCR, we show the presence of an alternatively spliced L5-67 transcript arising from the exclusion of the fourth exon from the mature mRNA. This alternative splicing event occurs specifically in the kidney, although we could not identify the cells in which it takes place. Translation of this transcript generates a 52 amino acid (aa) propeptide in which the first N-terminal 45 aa are identical to the original L5-67 propeptide. The last seven C-terminal aa are unrelated to the previously characterized L5-67 peptides due to a change in the open reading frame.


Asunto(s)
Empalme Alternativo , Aplysia/genética , Ganglios de Invertebrados/metabolismo , Neuronas/metabolismo , Neuropéptidos/genética , Secuencia de Aminoácidos , Animales , Aplysia/metabolismo , Secuencia de Bases , Clonación Molecular , Exones , Biblioteca Genómica , Hibridación in Situ , Riñón/metabolismo , Datos de Secuencia Molecular , Sistema Nervioso/metabolismo , Neuropéptidos/biosíntesis , Neuropéptidos/química , Especificidad de Órganos , Reacción en Cadena de la Polimerasa , ARN Mensajero/análisis , ARN Mensajero/biosíntesis , Transcripción Genética
8.
J Radiol ; 73(10): 501-13, 1992 Oct.
Artículo en Francés | MEDLINE | ID: mdl-1294723

RESUMEN

Abdominal symptoms are among the most frequent complaints of patients with AIDS. Because precise diagnosis from symptoms alone is difficult, the contribution of radiologist is important to fill in evaluating the cause of various illnesses. The review describes common clinical symptoms and lists the most likely causes with discussing the most appropriate imaging evaluation. For diagnosis and treatment, the most frequent and characteristics radiographic findings are described.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/complicaciones , Enfermedades del Sistema Digestivo/etiología , Enfermedades del Sistema Digestivo/diagnóstico por imagen , Humanos , Radiografía , Ultrasonografía
9.
J Lab Clin Med ; 93(4): 528-34, 1979 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-372467

RESUMEN

We have modified and adapted two well-accepted cancer immunology research techniques to study blood leukocyte phenomena of MS patients. The LAI test of Halliday and Miller and the 3 molar potassium chloride (3M KCl) tumor antigen extraction technique of Dean and McCoy were adapted to extract from pooled MS whole blood an MSRM. The LAI test results of 53 of 58 MS patients (91%) were considered positive, but only three of 75 control subjects (4%) were positive when tested against the MSRM. This indicates that patients with MS had a greater specific reactivity to the MSRM than did the control subjects (healthy individuals and patients with disease other than MS). The specificity and reproducibility of this reaction were tested with materials prepared from various malignant diseases. Sensitized leukocytes showed consistently higher reactivity to antigen extracts prepared from corresponding types of tumors than to extracts prepared from tumors of other histological types. Our results indicate that (1) the LAI test is able to corroborate the neurological diagnosis of MS and (2) there is a blood constituent found only in the MS patient.


Asunto(s)
Técnicas Inmunológicas , Prueba de Inhibición de Adhesión Leucocitaria , Esclerosis Múltiple/diagnóstico , Especificidad de Anticuerpos , Humanos , Esclerosis Múltiple/sangre
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