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1.
Integr Med Res ; 12(2): 100950, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37192979

RESUMEN

Background: The effectiveness and safety of Huashibaidu granule (HSBD) in treating mild Corona Virus Disease 2019 (COVID-19) patients infected with SARS-CoV-2 remain to be identified. We aimed to evaluate the effectiveness of HSBD in mild COVID-19 patients. Methods: A prospective, non-randomized, controlled study in mild COVID-19 patients was conducted in Shanghai, from April 8 to May 6, 2022. The enrolled patients were diagnosed as mild COVID-19. Finally, 360 patients received HSBD, and 368 patients received TCM placebo (administered orally 20 g twice daily for 7 days). The primary endpoints were the negative conversion rate of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and the negative conversion time. Secondary endpoints included the hospitalized days and the improvement in the clinical condition. Results: The negative conversion rate of SARS-CoV-2 at 7 days posttreatment in the HSBD group was higher than that in the control group (95.28% vs. 82.61%, P < 0.001). The median negative conversion time in the HSBD group was markedly decreased by 2 days compared with the control group (3 [3-6] vs. 5 [4-7], P < 0.001). In addition, the median hospitalized day was shortened in the HSBD group by 1 day compared with the control group (6 [4-7] vs. 7 [5-9], P < 0.001). The clinical improvement rate (275/360 [76.39%]) in the HSBD group within 7 days was significantly higher than that (203/368 [55.16%]) in the control group (P < 0.001). The improvement of symptom scores in the HSBD group was higher than that in the control group (2 [1-4] vs. 1 [1-2], P < 0.001). No severe adverse events occurred. Conclusions: Our study suggested that HSBD effectively increased the negative conversion rate of SARS-CoV-2 and shortened the negative conversion time and hospitalized days in mild COVID-19 patients. Clinical trial registration: Chinese Clinical Trial Registry, ChiCTR2200058668.

3.
Neuroimage Clin ; 24: 102072, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31734529

RESUMEN

Epilepsy, including the type with focal onset, is increasingly viewed as a disorder of the brain network. Here we employed the functional connectivity (FC) metrics estimated from the resting state functional MRI (rsfMRI) to investigate the changes of brain network associated with focal epilepsy caused by single cerebral cavernous malformation (CCM). Eight CCM subjects and 21 age and gender matched controls were enrolled in the study. Seven of 8 CCM subjects underwent surgical resection of the CCM and became seizure free and 4 of the surgical subjects underwent a repeat rsfMRI study. We showed that there was both regional and global disruption of the FC values among the CCM subjects including decreased in homotopic FC (HFC) and global FC (GFC) in the regions of interest (ROIs) where the CCMs were located. There was also the disruption of the default mode network (DMN) especially the FC between the middle prefrontal cortex (MPFC) and the right lateral parietal cortex (LPR) among these individuals. We observed the trend of alleviation of these disruptions after the individual has become seizure free from the surgical resection of the CCM. Using a voxel-based approach, we found the disruption of the HFC and GFC in the brain tissue immediately adjacent to the CCM and the severity of the disruption appeared inversely proportional to the distance of the brain tissue to the lesion. Our findings confirm the disruption of normal brain networks from focal epilepsy, a process that may be reversible with successful surgical treatments rendering patients seizure free. Some voxel-based metrics may help identify the epileptogenic zone and guide the surgical resection.


Asunto(s)
Encéfalo/diagnóstico por imagen , Neoplasias del Sistema Nervioso Central/diagnóstico por imagen , Epilepsias Parciales/diagnóstico por imagen , Hemangioma Cavernoso del Sistema Nervioso Central/diagnóstico por imagen , Vías Nerviosas/diagnóstico por imagen , Adolescente , Adulto , Anciano , Encéfalo/fisiopatología , Encéfalo/cirugía , Estudios de Casos y Controles , Neoplasias del Sistema Nervioso Central/complicaciones , Neoplasias del Sistema Nervioso Central/fisiopatología , Neoplasias del Sistema Nervioso Central/cirugía , Epilepsia Refractaria/diagnóstico por imagen , Epilepsia Refractaria/etiología , Epilepsia Refractaria/fisiopatología , Epilepsia Refractaria/cirugía , Epilepsias Parciales/etiología , Epilepsias Parciales/fisiopatología , Epilepsias Parciales/cirugía , Femenino , Neuroimagen Funcional , Hemangioma Cavernoso del Sistema Nervioso Central/complicaciones , Hemangioma Cavernoso del Sistema Nervioso Central/fisiopatología , Hemangioma Cavernoso del Sistema Nervioso Central/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiopatología , Procedimientos Neuroquirúrgicos , Adulto Joven
4.
World Neurosurg ; 93: 120-6, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27283183

RESUMEN

BACKGROUND: Psammoma bodies (PBs) are whorled, laminated hyaline spherules containing calcium deposits. Intracranially, the presence of PBs is associated with variants of meningioma and pituitary lesions, as well as aging choroid plexus. Limited information exists on their presence in vascular malformation. RESULTS: In this report, we describe a case of an adolescent male with drug-resistant epilepsy that was surgically managed at our regional epilepsy center. The epileptogenic focus was determined to be emanating from an indolent right insular lesion. Histopathologic evaluation showed the abundance of intravascular and perivascular PBs. Immunohistochemical evaluation confirmed the vascular origin using vascular markers. The unusual presence of PBs in a vascular lesion was unanticipated. CONCLUSIONS: Based on our case, we present the clinicoradiologic characteristics, supplemented with intraoperative findings, for this unusual lesion. In addition, because of the unusual presence of PBs in vascular lesions, we provide the findings of a systematic literature review to show the association of PBs with intracranial vascular lesions.


Asunto(s)
Epilepsia Refractaria/etiología , Epilepsia Refractaria/patología , Hemangioma Cavernoso del Sistema Nervioso Central/complicaciones , Hemangioma Cavernoso del Sistema Nervioso Central/patología , Calcificación Vascular/complicaciones , Calcificación Vascular/patología , Adolescente , Diagnóstico Diferencial , Humanos , Masculino
5.
Science ; 347(6227): 1226-9, 2015 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-25766228

RESUMEN

China's Chang'E-3 (CE-3) spacecraft touched down on the northern Mare Imbrium of the lunar nearside (340.49°E, 44.12°N), a region not directly sampled before. We report preliminary results with data from the CE-3 lander descent camera and from the Yutu rover's camera and penetrating radar. After the landing at a young 450-meter crater rim, the Yutu rover drove 114 meters on the ejecta blanket and photographed the rough surface and the excavated boulders. The boulder contains a substantial amount of crystals, which are most likely plagioclase and/or other mafic silicate mineral aggregates similar to terrestrial dolerite. The Lunar Penetrating Radar detection and integrated geological interpretation have identified more than nine subsurface layers, suggesting that this region has experienced complex geological processes since the Imbrian and is compositionally distinct from the Apollo and Luna landing sites.

7.
J Biol Chem ; 284(34): 22878-87, 2009 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-19542230

RESUMEN

It is well established that CpG promotes pro-inflammatory cytokine and antibody production by B cells via the Toll-like receptor 9 (TLR9)-dependent pathway. However, scavenger receptors (SRs) are also capable of binding such pathogen-derived molecules, yet their contribution to CpG-induced signaling events has not yet been evaluated. Here we identified a novel TLR9-independent mechanism of CpG-induced signaling and immune function that is mediated by the scavenger B1 receptor (SR-B1). Specifically, we show that CpG/SR-B1 triggers calcium entry into primary B lymphocytes via phospholipase C gamma-1-mediated activation of TRPC3 channels and also B cell adhesion to vascular cell adhesion molecule-1. CpG-induced calcium signals and vascular cell adhesion molecule-1 adhesion are TLR9-independent and are mediated exclusively by SR-B1. Although pro-inflammatory cytokine and Ig production induced by CpG require TLR9 expression, we also found that SR-B1 negatively regulates TLR9-dependent production of interleukin-6, interleukin-10, and IgM. Thus, our results provide a novel perspective on the complexity of CpG signaling within B cells by demonstrating that SR-B1 is an alternative pathway for nucleic acid-induced signaling that provides feedback inhibition on specific TLR9-dependent responses of B cells. Consequently, these results have wide implications for understanding the mechanisms regulating immune tolerance to nucleic acids and pathogen-associated molecules.


Asunto(s)
Linfocitos B/metabolismo , Fosfatos de Dinucleósidos/fisiología , Receptores Depuradores de Clase B/metabolismo , Transducción de Señal , Animales , Anticuerpos/metabolismo , Linfocitos B/efectos de los fármacos , Calcio/metabolismo , Células Cultivadas , Fosfatos de Dinucleósidos/farmacología , Electrofisiología , Humanos , Interleucina-10 , Ratones , Ratones Endogámicos C57BL , Técnicas de Placa-Clamp , Fosfolipasa C gamma/antagonistas & inhibidores , Fosfolipasa C gamma/metabolismo , Receptores Depuradores de Clase B/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Canales Catiónicos TRPC/genética , Canales Catiónicos TRPC/fisiología , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/fisiología
8.
J Immunol ; 182(2): 1021-32, 2009 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-19124745

RESUMEN

The highly homologous proteins ezrin, radixin, and moesin link proteins to the actin cytoskeleton. The two family members expressed in T cells, ezrin and moesin, are implicated in promoting T cell activation and polarity. To elucidate the contributions of ezrin and moesin, we conducted a systematic analysis of their function during T cell activation. In response to TCR engagement, ezrin and moesin were phosphorylated in parallel at the regulatory threonine, and both proteins ultimately localized to the distal pole complex (DPC). However, ezrin exhibited unique behaviors, including tyrosine phosphorylation and transient localization to the immunological synapse before movement to the DPC. To ask whether these differences reflect unique requirements for ezrin vs moesin in T cell signaling, we generated mice with conditional deletion of ezrin in mature T cells. Ezrin-/- T cells exhibited normal immunological synapse organization based upon localization of protein kinase C-theta, talin, and phospho-ZAP70. DPC localization of CD43 and RhoGDP dissociation inhibitor, as well as the novel DPC protein Src homology region 2 domain-containing phosphatase-1, was also unaffected. However, recruitment of three novel DPC proteins, ezrin binding protein of 50 kDa, Csk binding protein, and the p85 subunit of PI3K was partially perturbed. Biochemical analysis of ezrin-/- T cells or T cells suppressed for moesin using small interfering RNA showed intact early TCR signaling, but diminished levels of IL-2. The defects in IL-2 production were more pronounced in T cells deficient for both ezrin and moesin. These cells also exhibited diminished phospholipase C-gamma1 phosphorylation and calcium flux. We conclude that despite their unique movement and phosphorylation patterns, ezrin and moesin function together to promote T cell activation.


Asunto(s)
Proteínas del Citoesqueleto/fisiología , Activación de Linfocitos/inmunología , Proteínas de Microfilamentos/fisiología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Línea Celular , Células Cultivadas , Proteínas del Citoesqueleto/deficiencia , Proteínas del Citoesqueleto/genética , Humanos , Sinapsis Inmunológicas/genética , Células Jurkat , Activación de Linfocitos/genética , Proteínas de la Membrana/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Proteínas de Microfilamentos/deficiencia , Proteínas de Microfilamentos/genética , Receptores de Antígenos de Linfocitos T/fisiología , Transducción de Señal/inmunología
9.
Mol Cell Biol ; 27(17): 5986-6000, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17591693

RESUMEN

T-cell-receptor (TCR)-mediated integrin activation is required for T-cell-antigen-presenting cell conjugation and adhesion to extracellular matrix components. While it has been demonstrated that the actin cytoskeleton and its regulators play an essential role in this process, no mechanism has been established which directly links TCR-induced actin polymerization to the activation of integrins. Here, we demonstrate that TCR stimulation results in WAVE2-ARP2/3-dependent F-actin nucleation and the formation of a complex containing WAVE2, ARP2/3, vinculin, and talin. The verprolin-connecting-acidic (VCA) domain of WAVE2 mediates the formation of the ARP2/3-vinculin-talin signaling complex and talin recruitment to the immunological synapse (IS). Interestingly, although vinculin is not required for F-actin or integrin accumulation at the IS, it is required for the recruitment of talin. In addition, RNA interference of either WAVE2 or vinculin inhibits activation-dependent induction of high-affinity integrin binding to VCAM-1. Overall, these findings demonstrate a mechanism in which signals from the TCR produce WAVE2-ARP2/3-mediated de novo actin polymerization, leading to integrin clustering and high-affinity binding through the recruitment of vinculin and talin.


Asunto(s)
Integrina beta1/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Talina/metabolismo , Vinculina/metabolismo , Familia de Proteínas del Síndrome de Wiskott-Aldrich/metabolismo , Complejo 2-3 Proteico Relacionado con la Actina/genética , Complejo 2-3 Proteico Relacionado con la Actina/metabolismo , Actinas/metabolismo , Antígenos CD18/genética , Antígenos CD18/metabolismo , Calcio/metabolismo , Línea Celular , Citoesqueleto/metabolismo , Humanos , Sistema Inmunológico/fisiología , Integrina beta1/genética , Células Jurkat , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Complejos Multiproteicos , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas c-vav/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Transducción de Señal/fisiología , Familia de Proteínas del Síndrome de Wiskott-Aldrich/genética , Proteína de Unión al GTP cdc42/metabolismo , Proteína de Unión al GTP rac1/metabolismo
10.
Immunity ; 24(6): 741-752, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16782030

RESUMEN

HS1, the leukocyte-specific homolog of cortactin, regulates F-actin in vitro and is phosphorylated in response to TCR ligation, but its role in lymphocyte activation has not been addressed. We demonstrate that HS1-deficient T cells fail to accumulate F-actin at the immune synapse (IS) and, upon TCR ligation, form actin-rich structures that are disordered and unstable. Early TCR activation events are intact in these cells, but Ca2+ influx and IL-2 gene transcription are defective. Importantly, HS1 tyrosine phosphorylation is required for its targeting to the IS and for its function in regulating actin dynamics and IL-2 promoter activity. Phosphorylation also links HS1 to multiple signaling proteins, including Lck, PLCgamma1, and Vav1, and is essential for the stable recruitment of Vav1 to the IS. Taken together, our studies show that HS1 is indispensable for signaling events leading to actin assembly and IL-2 production during T cell activation.


Asunto(s)
Actinas/metabolismo , Proteínas Sanguíneas/metabolismo , Interleucina-2/genética , Linfocitos T/inmunología , Actinas/análisis , Proteínas Adaptadoras Transductoras de Señales , Animales , Proteínas Sanguíneas/análisis , Proteínas Sanguíneas/genética , Calcio/metabolismo , Células Cultivadas , Humanos , Activación de Linfocitos/genética , Ratones , Ratones Mutantes , Fosfolipasa C gamma/metabolismo , Fosforilación , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-vav/metabolismo , Receptores de Antígenos de Linfocitos T/agonistas , Receptores de Antígenos de Linfocitos T/metabolismo , Transcripción Genética , Tirosina/metabolismo
11.
J Immunol ; 176(4): 2229-37, 2006 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-16455979

RESUMEN

Developing thymocytes are positively selected if they respond to self-MHC-peptide complexes, yet mature T cells are not activated by those same self-complexes. To avoid autoimmunity, positive selection must be followed by a period of maturation when the cellular response to TCR signals is altered. The mechanisms that mediate this postselection developmental tuning remain largely unknown. Specifically, it is unknown whether developmental tuning is a preprogrammed outcome of positive selection or if it is sensitive to ongoing interactions between the thymocyte and the thymic stroma. We probed the requirement for MHC class II-TCR interactions in postselection maturation by studying single positive (SP) CD4 thymocytes from K14/A(beta)(b) mice, in which CD4 T cells cannot interact with MHC class II in the thymic medulla. We report here that SP CD4 thymocytes must receive MHC class II signals to avoid hyperactive responses to TCR signals. This hyperactivity correlates with decreased expression of CD5; however, developmental tuning can occur independently of CD5, correlating instead with differences in the distribution of Lck. Thus, the maturation of postselection SP CD4 thymocytes is an active process mediated by ongoing interactions between the T cell and MHC class II molecules. This represents a novel mechanism by which the thymic medulla prevents autoreactivity.


Asunto(s)
Diferenciación Celular , Regulación de la Expresión Génica , Antígenos de Histocompatibilidad Clase II/metabolismo , Timo/citología , Timo/metabolismo , Animales , Antígenos CD4/metabolismo , Antígenos CD5/metabolismo , Movimiento Celular , Proliferación Celular , Células Cultivadas , Antígenos de Histocompatibilidad Clase II/inmunología , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/metabolismo , Ratones , Ratones Noqueados , Receptores de Antígenos de Linfocitos T/metabolismo , Timo/inmunología
12.
Curr Biol ; 16(1): 24-34, 2006 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-16401421

RESUMEN

BACKGROUND: The engagement of the T cell receptor results in actin cytoskeletal reorganization at the immune synapse (IS) and the triggering of biochemical signaling cascades leading to gene regulation and, ultimately, cellular activation. Recent studies have identified the WAVE family of proteins as critical mediators of Rac1-induced actin reorganization in other cell types. However, whether these proteins participate in actin reorganization at the IS or signaling pathways in T cells has not been investigated. RESULTS: By using a combination of biochemical, genetic, and cell biology approaches, we provide evidence that WAVE2 is recruited to the IS, is biochemically modified, and is required for actin reorganization and beta-integrin-mediated adhesion after TCR crosslinking. Moreover, we show that WAVE2 regulates calcium entry at a point distal to PLCgamma1 activation and IP(3)-mediated store release. CONCLUSIONS: These data reveal a role for WAVE2 in regulating multiple pathways leading to T cell activation. In particular, this work shows that WAVE2 is a key component of the actin regulatory machinery in T cells and that it also participates in linking intracellular calcium store depletion to calcium release-activated calcium (CRAC) channel activation.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Canales de Calcio/metabolismo , Calcio/metabolismo , Linfocitos T/inmunología , Familia de Proteínas del Síndrome de Wiskott-Aldrich/fisiología , Citoesqueleto de Actina/ultraestructura , Espacio Extracelular/fisiología , Regulación de la Expresión Génica , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Células Jurkat , Activación de Linfocitos , Factores de Transcripción NFATC/genética , Factores de Transcripción NFATC/metabolismo , Fosfolipasa C gamma/metabolismo , Seudópodos/metabolismo , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Transducción de Señal , Linfocitos T/enzimología , Linfocitos T/ultraestructura , Transcripción Genética , Familia de Proteínas del Síndrome de Wiskott-Aldrich/genética
13.
Am J Physiol Cell Physiol ; 290(3): C873-82, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16251477

RESUMEN

Arachidonic acid (AA) is a substrate for a variety of proinflammatory mediators, which are generated by cyclooxygenases (COXs), lipoxygenases (LOXs), and cytochrome P-450 (CYP450) enzymes. COX (e.g., PGs and prostacyclins) and LOX (e.g., leukotrienes) products have well-established proinflammatory roles; however, little is known about the functions of CYP450 products in leukocytes. We previously found that mechanical strain generated by subjecting lymphocytes to hypotonic challenge triggered AA production and that two CYP450 products of AA, 5,6-epoxyeicosatrienoic acid (5,6-EET) and 20-hydroxyeicosatetraenoic acid (20-HETE), as well as a product of LOX, 5-(S)-hydroperoxyeicosatetrenoic acid (5-HPETE), induced Ca(2+) entry into primary B cells. The main goal of the present studies, therefore, was to define the biophysically properties of eicosanoid-activated channels responsible for Ca(2+) entry and the physiological consequences of activating these channels, including their role in mechanical signaling. We found that 5,6-EET, 20-HETE, and 5-HPETE each activated distinct Ca(2+)-permeant nonselective cation channels (NSCCs) in primary B cells. These NSCCs each regulate plasma membrane potential and B-cell adhesion to integrin ligands ICAM-1 and VCAM-1. Thus our data demonstrate that proinflammatory mediators produced in response to osmotic and/or physical stress play a direct role in regulating the B-cell membrane potential and their adhesion to specific ECM proteins. These results not only have important implications for understanding normal mechanisms of B-cell activation, differentiation, and trafficking but also point to novel targets for modulating the pathogenesis of B-cell-mediated inflammatory diseases.


Asunto(s)
Linfocitos B/citología , Linfocitos B/metabolismo , Eicosanoides/farmacología , Molécula 1 de Adhesión Intercelular/metabolismo , Canales Iónicos/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo , Linfocitos B/efectos de los fármacos , Calcio/metabolismo , Adhesión Celular/efectos de los fármacos , Ligandos , Potenciales de la Membrana , Unión Proteica/efectos de los fármacos
14.
J Immunol ; 175(8): 4981-9, 2005 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-16210600

RESUMEN

We previously characterized the initial steps in the activation of novel (calcium-permeant) nonselective cation channels (NSCCs) and calcium release-activated calcium channels in primary murine B lymphocytes. Phospholipase C products, namely diacylglycerol and d-myo-inositol 1,4,5-trisphosphate, were identified as proximal intracellular agonists of these respective channels following mechanical stimulation of B cells. However, neither the distal steps in NSCC activation nor the contribution of these channels to sustained mechanical signaling were defined in these previous studies. In this study, single cell measurements of intracellular Ca(2+) were used to define the mechanisms of NSCC activation and demonstrate a requirement for arachidonic acid liberated from diacylglycerol. Several arachidonic acid-derived derivatives were identified that trigger Ca(2+) entry into B cells, including the lipoxygenase product 5-hydroperoxyeicosatetranenoic acid and the cytochrome P450 hydroxylase product 20-hydroxyeicosatetraenoic; however, the cytochrome P450 epoxygenase product 5,6-epoxyeicosatrienoic acid is primarily responsible for hypotonicity-induced responses. In addition to regulating calcium entry, our data suggest that eicosanoid-activated NSCCs have a separate and direct role in regulating the avidity of integrins on B cells for extracellular matrix proteins, including ICAM-1 and VCAM-1. Thus, in addition to defining a novel osmotically activated signal transduction pathway in B cells, our results have broad implications for understanding how inflammatory mediators dynamically and rapidly regulate B cell adhesion and trafficking.


Asunto(s)
Ácidos Araquidónicos/fisiología , Linfocitos B/fisiología , Señalización del Calcio/fisiología , Mediadores de Inflamación/fisiología , Integrinas/metabolismo , Animales , Calcio/metabolismo , Células Cultivadas , Medios de Cultivo , Diglicéridos/fisiología , Eicosanoides/fisiología , Ratones , Presión Osmótica , Receptores de Antígenos de Linfocitos B/fisiología
15.
J Neurosci Res ; 81(6): 817-26, 2005 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-16041798

RESUMEN

Although prostaglandin E2 (PGE2) has been shown to be critical to hippocampal synaptic signaling and neuronal survival, it is still not clear which subtypes of PGE2 receptors (EPs) are expressed and how these EPs are regulated in the hippocampus. To address these questions, the expression of the EPs was profiled in the hippocampus. Messenger RNAs and proteins of the four receptors, EP 1-4, were detected both in the hippocampus and in the neocortex. EP 2 and EP 3 appeared in greater abundance, whereas EP 1 and EP 4 were barely detectable. EP 1, EP 2 and EP 4 were mainly colocalized with synaptophysin, suggesting the presence of EP 1, EP 2, and EP 4 in presynaptic terminals. It appeared that interleukin-1 beta increased the expression of EP 2 and EP 4 mRNAs. A blockade of synaptic transmission with either tetrodotoxin or MK-801 plus 6,7-dinitroquinoxaline-2,3-dione (DNQX) for 6 hr increased EP 3 and EP 4 mRNA, whereas high K(+) (90 mM) or 4-aminopyridine enhanced EP 2 and EP 4. The EP 1 level did not change significantly under these conditions. The expressions of EP 2, EP 4, and EP 3 were further elevated or reduced in neurons treated with high K(+) for 24 hr. However, mRNA of EP 3 was down-regulated in neurons treated with tetrodotoxin or MK-801 plus DNQX for 24 hr. In addition, both EP 2 and EP 4 mRNAs were up-regulated within 4 hr after high-frequency stimulation associated with long-term potentiation induction in hippocampal slices. Our results indicate that the four EPs are heterogeneously expressed in the hippocampus, and their expression is differentially regulated by neuronal activities, suggesting that EPs may actively participate in hippocampal synaptic transmission and plasticity.


Asunto(s)
Hipocampo/metabolismo , Receptores de Prostaglandina E/metabolismo , Animales , Células Cultivadas , Regulación de la Expresión Génica/fisiología , Hipocampo/citología , Hipocampo/fisiología , Immunoblotting , Inmunohistoquímica , Potenciación a Largo Plazo/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Neuronas , ARN/biosíntesis , Ratas , Ratas Sprague-Dawley , Receptores Acoplados a Proteínas G/fisiología , Receptores de Prostaglandina E/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Membranas Sinápticas/fisiología
16.
J Neurosci Res ; 77(4): 525-31, 2004 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-15264222

RESUMEN

Platelet-activating factor (PAF) is a potent phospholipid messenger in the nervous system that participates in synaptic plasticity and in pathologic processes, including neurodegeneration. Oxidative stress plays important roles in neuronal cell death. To define the interaction between PAF and oxidative radicals in neuronal death, we studied the effects of PAF in the presence of oxidative radicals in primary neurons in culture. Exogenous PAF (50 microM) caused PAF receptor-independent injury to neurons. A nonneurotoxic PAF concentration (500 nM) potentiated neuronal death caused by hydrogen peroxide as determined by lactate dehydrogenase (LDH) assay, Hoechst staining, and TUNEL analysis, but it did not potentiate neuronal death caused by menadione, a superoxide donor, or by the nitric oxide donors 3-morpholino-sydnonimine (SIN-1) and sodium nitroprusside (SNP). This potentiation of the hydrogen peroxide effect was selectively blocked by a PAF membrane-receptor antagonist, BN52021 (5 microM). The neurotoxic effect of PAF and hydrogen peroxide was also completely blocked by ebselen and partially decreased by pretreatment with (S)-3,5-dihydroxyphenylglycine (DHPG), a group I metabotropic glutamate receptor (mGluR) agonist. This study suggests that PAF-receptor antagonists may be useful for neuroprotection. A similar effect might also be obtained with group I mGluR agonists, probably by way of a different underlying mechanism.


Asunto(s)
Muerte Celular/fisiología , Degeneración Nerviosa/metabolismo , Estrés Oxidativo/fisiología , Factor de Activación Plaquetaria/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Animales , Antioxidantes/farmacología , Azoles/farmacología , Muerte Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Células Cultivadas , Diterpenos/farmacología , Agonistas de Aminoácidos Excitadores/farmacología , Radicales Libres/metabolismo , Ginkgólidos , Peróxido de Hidrógeno/farmacología , Isoindoles , L-Lactato Deshidrogenasa/metabolismo , Lactonas/farmacología , Degeneración Nerviosa/fisiopatología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacología , Donantes de Óxido Nítrico , Compuestos de Organoselenio/farmacología , Estrés Oxidativo/efectos de los fármacos , Factor de Activación Plaquetaria/antagonistas & inhibidores , Factor de Activación Plaquetaria/farmacología , Glicoproteínas de Membrana Plaquetaria/antagonistas & inhibidores , Glicoproteínas de Membrana Plaquetaria/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Receptores Acoplados a Proteínas G/metabolismo , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Vitamina K 3/farmacología
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