RESUMEN

The novel coronavirus (COVID-19) pneumonia has been classified as a category B and dealt with as a category A infectious disease by the National Health Commission of China, and also as a public health emergency of international concern by the World Health Organization. During the epidemic, unnecessary visits to hospitals may increase the risk of infection among patients and clinicians. Therefore, it is particularly important to provide some scientific medical guidance for patients with male diseases, which is also a current imperative for andrology management. And it also deserves the attention of clinical researchers whether COVID-19 pneumonia and its clinical treatments currently used may affect the male reproductive system.

Asunto(s)

Andrología , COVID-19/epidemiología , Enfermedades del Sistema Endocrino/terapia , Enfermedades Urogenitales Masculinas/terapia , China/epidemiología , Manejo de la Enfermedad , Humanos , Masculino

RESUMEN

OBJECTIVE: To investigate the clinical feasibility and effect of nerve-sparing robot-assisted laparoscopic radical cystectomy (NSRA-LSRC). METHODS: We retrospectively reviewed the clinical data on 12 cases of NSRA-LSRC performed from March 2016 to May 2018. The patients were aged 45 to 65 years old and all potent before surgery, with a mean IIEF-5 score of >17. The surgical procedure involved excision of the bladder and prostate and dissection of the pelvic lymph nodes, with preservation of the bilateral neurovascular bundles, internal accessory pudendal artery and pubic bladder complex. All the patients were advised to take PDE5I postoperatively and followed up for the sexual function with the IIEF-5 scores. RESULTS: Surgical procedures were completed successfully, all with negative surgical margins. Postoperative pathology confirmed invasive high-grade urothelial carcinoma or carcinoma in situ in all the cases, including 11 cases in stage T2N0M0 or below and 1 case in stage T3aN0M0. There were no serious intraoperative or postoperative complications, nor recurrence or metastasis during the follow-up period of 12－36 (20.7 ± 8.0) months. The IIEF-5 scores of the patients at 3, 6 and 12 months after operation were 10.9 ± 6.9, 12.3 ± 6.9 and 14.1 ± 8.0, respectively. At 12 months, satisfactory sexual intercourse was achieved with the help of potency-enhancing medicine in 5 cases (41.7%), penile erection insufficient for sexual intercourse in 3 cases (25%), and no erection in 4 cases (33.3%). CONCLUSIONS: Nerve-sparing robot-assisted laparoscopic radical cystectomy can maximally preserve the sexual function of the patients with urinary bladder carcinoma.

Asunto(s)

Cistectomía/métodos , Laparoscopía , Procedimientos Quirúrgicos Robotizados , Neoplasias de la Vejiga Urinaria/cirugía , Anciano , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Tratamientos Conservadores del Órgano , Erección Peniana , Estudios Retrospectivos

RESUMEN

Mobilization of hematopoietic stem cells (HSCs) from bone marrow (BM) to peripheral blood (PB) by cytokine granulocyte colony-stimulating factor (G-CSF) or the chemical antagonist of CXCR4, AMD3100, is important in the treatment of blood diseases. Due to clinical conditions of each application, there is a need for continued improvement of HSC mobilization regimens. Previous studies have shown that genetic ablation of the Rho GTPase Cdc42 in HSCs results in their mobilization without affecting survival. Here we rationally identified a Cdc42 activity-specific inhibitor (CASIN) that can bind to Cdc42 with submicromolar affinity and competitively interfere with guanine nucleotide exchange activity. CASIN inhibits intracellular Cdc42 activity specifically and transiently to induce murine hematopoietic stem/progenitor cell egress from the BM by suppressing actin polymerization, adhesion, and directional migration of stem/progenitor cells, conferring Cdc42 knockout phenotypes. We further show that, although, CASIN administration to mice mobilizes similar number of phenotypic HSCs as AMD3100, it produces HSCs with better long-term reconstitution potential than that by AMD3100. Our work validates a specific small molecule inhibitor for Cdc42, and demonstrates that signaling molecules downstream of cytokines and chemokines, such as Cdc42, constitute a useful target for long-term stem cell mobilization.

Asunto(s)

Células Madre Hematopoyéticas/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Proteína de Unión al GTP cdc42/antagonistas & inhibidores , Animales , Bencilaminas , Médula Ósea/efectos de los fármacos , Médula Ósea/metabolismo , Movimiento Celular/efectos de los fármacos , Ciclamas , Citocinas/metabolismo , Factor Estimulante de Colonias de Granulocitos/metabolismo , Movilización de Célula Madre Hematopoyética/métodos , Trasplante de Células Madre Hematopoyéticas/métodos , Células Madre Hematopoyéticas/metabolismo , Compuestos Heterocíclicos/farmacología , Ratones , Ratones Endogámicos C57BL , Células Madre/efectos de los fármacos , Células Madre/metabolismo

Asunto(s)

Supervivencia de Injerto , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Acondicionamiento Pretrasplante , Animales , Biomarcadores , Diferenciación Celular , Expresión Génica , Técnicas de Inactivación de Genes , Marcación de Gen , Enfermedades Hematológicas/etiología , Enfermedades Hematológicas/metabolismo , Enfermedades Hematológicas/mortalidad , Enfermedades Hematológicas/terapia , Humanos , Inmunofenotipificación , Ratones , Modelos Animales , Acondicionamiento Pretrasplante/métodos

RESUMEN

The Ras family small GTPases regulate multiple cellular processes, including cell growth, survival, movement, and gene expression, and are intimately involved in cancer pathogenesis. Activation of these small GTPases is catalyzed by a special class of enzymes, termed guanine nucleotide exchange factors (GEFs). Herein, we developed a small molecule screening platform for identifying lead hits targeting a Ras GEF enzyme, SOS1. We employed an ensemble structure-based virtual screening approach in combination with a multiple tier high throughput experimental screen utilizing two complementary fluorescent guanine nucleotide exchange assays to identify small molecule inhibitors of GEF catalytic activity toward Ras. From a library of 350,000 compounds, we selected a set of 418 candidate compounds predicted to disrupt the GEF-Ras interaction, of which dual wavelength GDP dissociation and GTP-loading experimental screening identified two chemically distinct small molecule inhibitors. Subsequent biochemical validations indicate that they are capable of dose-dependently inhibiting GEF catalytic activity, binding to SOS1 with micromolar affinity, and disrupting GEF-Ras interaction. Mutagenesis studies in conjunction with structure-activity relationship studies mapped both compounds to different sites in the catalytic pocket, and both inhibited Ras signaling in cells. The unique screening platform established here for targeting Ras GEF enzymes could be broadly useful for identifying lead inhibitors for a variety of small GTPase-activating GEF reactions.

Asunto(s)

Inhibidores Enzimáticos , Proteínas Activadoras de ras GTPasa/antagonistas & inhibidores , Factores de Intercambio de Guanina Nucleótido ras/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Sistemas de Liberación de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/métodos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteínas Activadoras de ras GTPasa/genética , Proteínas Activadoras de ras GTPasa/metabolismo , Factores de Intercambio de Guanina Nucleótido ras/genética , Factores de Intercambio de Guanina Nucleótido ras/metabolismo

RESUMEN

Mild traumatic brain injury (MTBI) is defined as a mild brain trauma resulting in a short loss of consciousness and alteration of mental status. It may also occasionally develop persistent and progressive symptoms. It has been confirmed that MTBI causes changes of anatomic structures in central nervous system and biomarkers in the body fluid. However, there is no sufficient research on relevance among threshold for the brain injury, individual vulnerability and duration of disturbance of consciousness. Furthermore, there are no reliable diagnostic methods to establish whether a blow to the head is sufficient to cause the brain injury. This review provides references for biomarkers in cerebrospinal fluid and blood associated with TBI. It also provides application status and potential prospects for further assessment and diagnosis of MTBI.

Asunto(s)

Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Lesiones Encefálicas/sangre , Lesiones Encefálicas/líquido cefalorraquídeo , Conmoción Encefálica/complicaciones , Lesiones Encefálicas/diagnóstico , Lesiones Encefálicas/etiología , Progresión de la Enfermedad , Humanos

RESUMEN

Mild traumatic brain injury (MTBI) is defined as a mild brain trauma resulting in a short loss of consciousness and alteration of mental status. It may also occasionally develop persistent and progressive symptoms. It has been confirmed that MTBI causes changes of anatomic structures in central nervous system and biomarkers in the body fluid. However, there is no sufficient research on relevance among threshold for the brain injury, individual vulnerability and duration of disturbance of consciousness. Furthermore, there are no reliable diagnostic methods to establish whether a blow to the head is sufficient to cause the brain injury. This review provides references for biomarkers in cerebrospinal fluid and blood associated with TBI. It also provides application status and potential prospects for further assessment and diagnosis of MTBI.

Asunto(s)

Humanos , Biomarcadores/líquido cefalorraquídeo , Conmoción Encefálica/complicaciones , Lesiones Encefálicas/etiología , Progresión de la Enfermedad

RESUMEN

The G-protein-mediated Rho guanine nucleotide exchange factor (GEF)-Rho GTPase signaling axis has been implicated in human pathophysiology and is a potential therapeutic target. By virtual screening of chemicals that fit into a surface groove of the DH-PH domain of LARG, a G-protein-regulated Rho GEF involved in RhoA activation, and subsequent validations in biochemical assays, we have identified a class of chemical inhibitors represented by Y16 that are active in specifically inhibiting LARG binding to RhoA. Y16 binds to the junction site of the DH-PH domains of LARG with a ∼80 nM K(d) and suppresses LARG catalyzed RhoA activation dose dependently. It is active in blocking the interaction of LARG and related G-protein-coupled Rho GEFs with RhoA without a detectable effect on other DBL family Rho GEFs, Rho effectors, or a RhoGAP. In cells, Y16 selectively inhibits serum-induced RhoA activity and RhoA-mediated signaling, effects that can be rescued by a constitutively active RhoA or ROCK mutant. By suppressing RhoA activity, Y16 inhibits mammary sphere formation of MCF7 breast cancer cells but does not affect the nontransforming MCF10A cells. Significantly, Y16 works synergistically with Rhosin/G04, a Rho GTPase activation site inhibitor, in inhibiting LARG-RhoA interaction, RhoA activation, and RhoA-mediated signaling functions. Thus, our studies show that Rho GEFs can serve as selective targets of small chemicals and present a strategy of dual inhibition of the enzyme-substrate pair of GEF-RhoA at their binding interface that leads to enhanced efficacy and specificity.

Asunto(s)

Factores de Intercambio de Guanina Nucleótido/antagonistas & inhibidores , Secuencia de Aminoácidos , División Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Humanos , Invasividad Neoplásica/prevención & control , Homología de Secuencia de Aminoácido

RESUMEN

OBJECTIVE: To explore the applicability of magnetic resonance diffusion tensor imaging (DTI) for diagnosis of pyramidal tract damage in rats. METHODS: Marmarou's model was set up, followed by DTI scanning at 3, 12, 24 and 72 h post trauma to acquire the dispersion parameter of bilateral pyramidal tracts. Moreover, axonal varicosities per square millimeter and the percentage of positive area of axons demonstrated by beta-amyloid precursor protein (beta-APP) immunostaining were obtained, as well as the mean density and sum density of neurofilament (NF) 68 immunostaining. RESULTS: Axial diffusivity (AD), fraction anisotropy (FA) and relative anisotropy (RA) in the pyramidal tract were significantly and continuously reduced and reached to the bottom at 72h post trauma (P < 0.05) in accord with the gradient of axonal damage verified by beta-APP and NF68 immunostaining. Furthermore, the changes of AD, FA and RA showed a significant negative correlation with the beta-APP immunohistochemical results. CONCLUSION: DTI has important value for early diagnosis in pyramidal tract damage.

Asunto(s)

Lesiones Encefálicas/diagnóstico , Encéfalo/patología , Imagen de Difusión por Resonancia Magnética/métodos , Tractos Piramidales/patología , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Anisotropía , Axones/patología , Encéfalo/metabolismo , Lesiones Encefálicas/metabolismo , Lesiones Encefálicas/patología , Modelos Animales de Enfermedad , Procesamiento de Imagen Asistido por Computador , Masculino , Proteínas de Neurofilamentos/metabolismo , Tractos Piramidales/metabolismo , Ratas , Ratas Sprague-Dawley , Índice de Severidad de la Enfermedad , Factores de Tiempo

RESUMEN

Rho GTPases have been implicated in diverse cellular functions and are potential therapeutic targets in inflammation, cancer, and neurologic diseases. Virtual screening of compounds that fit into surface grooves of RhoA known to be critical for guanine nucleotide exchange factor (GEF) interaction produced chemical candidates with minimized docking energy. Subsequent screening for inhibitory activity of RhoA binding to the Rho-GEF, LARG, identified a Rho-specific inhibitor as a lead compound capable of blocking RhoA-LARG interaction and RhoA activation by LARG specifically and dose dependently. A microscale thermophoresis analysis was applied to directly quantify the binding interaction of the lead inhibitor with RhoA target. The lead inhibitor highlights the principle that rational targeting of subfamily members of Rho GTPases is feasible and potentially useful in future drug design effort.

Asunto(s)

Diseño de Fármacos , Evaluación Preclínica de Medicamentos/métodos , Inhibidores Enzimáticos/farmacología , Proteínas de Unión al GTP rho/antagonistas & inhibidores , Programas Informáticos , Proteína de Unión al GTP rhoA/metabolismo

RESUMEN

Rho GTPases have been implicated in diverse cellular functions and are potential therapeutic targets. By virtual screening, we have identified a Rho-specific inhibitor, Rhosin. Rhosin contains two aromatic rings tethered by a linker, and it binds to the surface area sandwiching Trp58 of RhoA with a submicromolar Kd and effectively inhibits GEF-catalyzed RhoA activation. In cells, Rhosin specifically inhibited RhoA activity and RhoA-mediated cellular function without affecting Cdc42 or Rac1 signaling activities. By suppressing RhoA or RhoC activity, Rhosin could inhibit mammary sphere formation by breast cancer cells, suppress invasion of mammary epithelial cells, and induce neurite outgrowth of PC12 cells in synergy with NGF. Thus, the rational designed RhoA subfamily-specific small molecule inhibitor is useful for studying the physiological and pathologic roles of Rho GTPase.

Asunto(s)

Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Compuestos Orgánicos/farmacología , Proteínas de Unión al GTP rho/antagonistas & inhibidores , Animales , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Modelos Moleculares , Peso Molecular , Compuestos Orgánicos/síntesis química , Compuestos Orgánicos/química , Ratas , Relación Estructura-Actividad , Proteínas de Unión al GTP rho/metabolismo

RESUMEN

OBJECTIVE@#To explore the applicability of magnetic resonance diffusion tensor imaging (DTI) for diagnosis of pyramidal tract damage in rats.@*METHODS@#Marmarou's model was set up, followed by DTI scanning at 3, 12, 24 and 72 h post trauma to acquire the dispersion parameter of bilateral pyramidal tracts. Moreover, axonal varicosities per square millimeter and the percentage of positive area of axons demonstrated by beta-amyloid precursor protein (beta-APP) immunostaining were obtained, as well as the mean density and sum density of neurofilament (NF) 68 immunostaining.@*RESULTS@#Axial diffusivity (AD), fraction anisotropy (FA) and relative anisotropy (RA) in the pyramidal tract were significantly and continuously reduced and reached to the bottom at 72h post trauma (P < 0.05) in accord with the gradient of axonal damage verified by beta-APP and NF68 immunostaining. Furthermore, the changes of AD, FA and RA showed a significant negative correlation with the beta-APP immunohistochemical results.@*CONCLUSION@#DTI has important value for early diagnosis in pyramidal tract damage.

Asunto(s)

Animales , Masculino , Ratas , Precursor de Proteína beta-Amiloide/metabolismo , Anisotropía , Axones/patología , Encéfalo/patología , Lesiones Encefálicas/patología , Imagen de Difusión por Resonancia Magnética/métodos , Modelos Animales de Enfermedad , Procesamiento de Imagen Asistido por Computador , Proteínas de Neurofilamentos/metabolismo , Tractos Piramidales/patología , Ratas Sprague-Dawley , Índice de Severidad de la Enfermedad , Factores de Tiempo

RESUMEN

Epithelial invagination is a common feature of embryogenesis. An example of invagination morphogenesis occurs during development of the early eye when the lens placode forms the lens pit. This morphogenesis is accompanied by a columnar-to-conical cell shape change (apical constriction or AC) and is known to be dependent on the cytoskeletal protein Shroom3. Because Shroom3-induced AC can be Rock1/2 dependent, we hypothesized that during lens invagination, RhoA, Rock and a RhoA guanine nucleotide exchange factor (RhoA-GEF) would also be required. In this study, we show that Rock activity is required for lens pit invagination and that RhoA activity is required for Shroom3-induced AC. We demonstrate that RhoA, when activated and targeted apically, is sufficient to induce AC and that RhoA plays a key role in Shroom3 apical localization. Furthermore, we identify Trio as a RhoA-GEF required for Shroom3-dependent AC in MDCK cells and in the lens pit. Collectively, these data indicate that a Trio-RhoA-Shroom3 pathway is required for AC during lens pit invagination.

Asunto(s)

Forma de la Célula/fisiología , Células Epiteliales/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Cristalino/embriología , Proteínas de Microfilamentos/metabolismo , Morfogénesis/fisiología , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal/fisiología , Proteínas de Unión al GTP rho/metabolismo , Animales , Línea Celular , Embrión de Pollo , Crioultramicrotomía , Perros , Electroporación , Técnica del Anticuerpo Fluorescente , Ratones , Análisis de Regresión , Quinasas Asociadas a rho/metabolismo , Proteína de Unión al GTP rhoA

RESUMEN

Traumatic brain injury (TBI) is a highly complex multi-factorial disorder. Animal models of TBI are used to elucidate primary and secondary injury mechanisms and pathophysiological changes and to provide the diagnostic and therapeutical basis for TBI. The choices of animal models depend upon the research objectives. However, various animal models have limitations. The models only can duplicate the pivotal injury mechanisms or a certain important pathophysiological course. The characteristics of human TBI can not fully be reflected by using these models. In the review, animal models of traumatic brain injury are classified as dynamic direct brain injury, indirect dynamic brain injury and combined neuro-traumatic models. Several common models are described for consideration.

Asunto(s)

Lesiones Encefálicas/fisiopatología , Encéfalo/fisiopatología , Modelos Animales de Enfermedad , Traumatismos Cerrados de la Cabeza/fisiopatología , Traumatismos Penetrantes de la Cabeza/fisiopatología , Animales , Fenómenos Biomecánicos , Encéfalo/patología , Lesiones Encefálicas/patología , Lesión Axonal Difusa/patología , Lesión Axonal Difusa/fisiopatología , Medicina Legal , Traumatismos Cerrados de la Cabeza/patología , Traumatismos Penetrantes de la Cabeza/patología , Humanos , Ratones , Ratas , Reproducibilidad de los Resultados

RESUMEN

BACKGROUND: Cdc42 and Rac1, members of the Rho family of small GTPases, play critical roles in actin cytoskeleton regulation. We have shown previously that Rac1 is involved in regulation of platelet secretion and aggregation. However, the role of Cdc42 in platelet activation remains controversial. This study was undertaken to better understand the role of Cdc42 in platelet activation. METHODOLOGY/PRINCIPAL FINDINGS: We utilized the Mx-cre;Cdc42(lox/lox) inducible mice with transient Cdc42 deletion to investigate the involvement of Cdc42 in platelet function. The Cdc42-deficient mice exhibited a significantly reduced platelet count than the matching Cdc42(+/+) mice. Platelets isolated from Cdc42(-/-), as compared to Cdc42(+/+), mice exhibited (a) diminished phosphorylation of PAK1/2, an effector molecule of Cdc42, (b) inhibition of filopodia formation on immobilized CRP or fibrinogen, (c) inhibition of CRP- or thrombin-induced secretion of ATP and release of P-selectin, (d) inhibition of CRP, collagen or thrombin induced platelet aggregation, and (e) minimal phosphorylation of Akt upon stimulation with CRP or thrombin. The bleeding times were significantly prolonged in Cdc42(-/-) mice compared with Cdc42(+/+) mice. CONCLUSION/SIGNIFICANCE: Our data demonstrate that Cdc42 is required for platelet filopodia formation, secretion and aggregation and therefore plays a critical role in platelet mediated hemostasis and thrombosis.

Asunto(s)

Plaquetas/metabolismo , Marcación de Gen , Agregación Plaquetaria , Glicoproteínas de Membrana Plaquetaria/metabolismo , Seudópodos/metabolismo , Proteína de Unión al GTP cdc42/deficiencia , Animales , Tiempo de Sangría , Plaquetas/efectos de los fármacos , Plaquetas/enzimología , Médula Ósea/efectos de los fármacos , Médula Ósea/metabolismo , Proteínas Portadoras/farmacología , Activación Enzimática/efectos de los fármacos , Fibrinógeno/farmacología , Eliminación de Gen , Ratones , Péptidos/farmacología , Agregación Plaquetaria/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Seudópodos/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Trombina/farmacología , Trombocitopenia/metabolismo , Trombocitopenia/patología , Proteína de Unión al GTP cdc42/metabolismo , Quinasas p21 Activadas/metabolismo

RESUMEN

Rho GTPases including RhoA, Rac1, and Cdc42 are a class of intracellular signaling proteins critical for the regulation of cytoskeleton organization, adhesion, and migration. Molecular mechanisms of mammalian cell migration were first revealed in fibroblasts where RhoA, Rac1, and Cdc42 facilitate in the multistep process including establishment and maintenance of polarity, formation of actin-rich protrusions, remodeling of adhesive contacts, and generation of force. In hematopoietic stem/progenitor cells, Rho GTPases relay signals from chemokines and cytokines such as SDF-1α and SCF to the actin and microtubule cytoskeleton through effector kinases and/or adaptor molecules that affect adhesion or transcription. Comprehensive use of murine conditional gene knockout technology combined with biochemical approaches in recent studies allows for physiologically relevant investigations of the involvement of Rho GTPases in hematopoietic stem/progenitor cell migration, providing important mechanisms for the stem/progenitor maintenance.

Asunto(s)

Citoesqueleto/fisiología , Células Madre Hematopoyéticas , Neuropéptidos/fisiología , Transducción de Señal , Proteína de Unión al GTP cdc42/fisiología , Proteínas de Unión al GTP rac/fisiología , Proteínas de Unión al GTP rho/fisiología , Actinas/fisiología , Animales , Adhesión Celular/fisiología , Línea Celular , Ensayos de Migración Celular , Movimiento Celular , Células Endoteliales/citología , Células Endoteliales/fisiología , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/fisiología , Inmunoprecipitación , Ratones , Ratones Noqueados , Transducción de Señal/fisiología , Proteína de Unión al GTP rac1 , Proteína de Unión al GTP rhoA

RESUMEN

Adult hematopoietic progenitor cells (HPCs) are maintained by highly coordinated signals in the bone marrow. The molecular mechanisms linking intracellular signaling network of HPCs with their microenvironment remain poorly defined. The Rho family GTPase Rac1/Rac2 has previously been implicated in cell functions involved in HPC maintenance, including adhesion, migration, homing, and mobilization. In the present studies we have identified R-Ras, a member of the Ras family, as a key signal mediator required for Rac1/Rac2 activation. We found that whereas Rac1 activity is up-regulated upon stem cell factor, integrin, or CXCL12 stimulation, R-Ras activity is inversely up-regulated. Expression of a constitutively active R-Ras mutant resulted in down-regulation of Rac1-activity whereas deletion of R-Ras led to an increase in Rac1/Rac2 activity and signaling. R-Ras(-/-) HPCs displayed a constitutively assembled cortical actin structure and showed increased directional migration. Rac1/Rac2 inhibition reversed the migration phenotype of R-Ras(-/-) HPCs, similar to that by expressing an R-Ras active mutant. Furthermore, R-Ras(-/-) mice showed enhanced responsiveness to G-CSF for HPC mobilization and exhibited decreased bone marrow homing. Transplantation experiments indicate that the R-Ras deficiency-induced HPC mobilization is a HPC intrinsic property. These results indicate that R-Ras is a critical regulator of Rac signaling required for HPC migration, homing, and mobilization.

Asunto(s)

Movimiento Celular/fisiología , Células Madre Hematopoyéticas/enzimología , Neuropéptidos/metabolismo , Transducción de Señal/fisiología , Proteínas de Unión al GTP rac/metabolismo , Proteínas ras/metabolismo , Actinas/genética , Actinas/metabolismo , Células Madre Adultas/citología , Células Madre Adultas/enzimología , Animales , Activación Enzimática/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Movilización de Célula Madre Hematopoyética , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/citología , Ratones , Ratones Noqueados , Mutación , Neuropéptidos/genética , Trasplante Homólogo , Regulación hacia Arriba/fisiología , Proteínas de Unión al GTP rac/genética , Proteína de Unión al GTP rac1 , Proteínas ras/genética , Proteína RCA2 de Unión a GTP

RESUMEN

BACKGROUND: Experimental analyses have identified strain-dependent factors that regulate susceptibility to anaphylaxis in mice. We assessed the susceptibility of the widely used 129SvEvBrd (also known as 129S5) mouse strain to IgE/mast cell-mediated anaphylaxis as compared to BALB/c. Mice were subjected to passive and oral Ovalbumin [OVA]-induced active anaphylaxis. Tissue mast cell, plasma histamine, total IgE and OVA-specific IgE levels and susceptibility to histamine i.v infusion were assessed. Bone marrow mast cell (BMMC)s were examined for FcεRI, c-kit, degranulation efficiency, proliferation, apoptosis and cytokine profile. RESULTS: 129S5 mice had significantly increased susceptibility to passive and oral OVA-induced active anaphylaxis. Increased susceptibility to anaphylaxis was associated with increased homeostatic mast cell levels but not OVA-specific IgE or IgG1 levels. In vitro analyses of BMMCs revealed no difference in FcεRI and c-Kit expression, however, 129S5 BMMCs possessed greater proliferative capacity and reduced caspase-3-mediated apoptosis. IgE-BMMC degranulation assays demonstrated no difference in degranulation efficiency. Furthermore, 129S5 mice possessed increased sensitivity to histamine-induced hypothermia. CONCLUSIONS: We conclude that 129S5 mice have increased susceptibility to anaphylaxis as compared to BALB/c strain and their increased susceptibility was associated with altered mast cell proliferation and homeostatic tissue levels and responsiveness to histamine. Given the wide spread usage of the 129SvEvBrd strain of mice in experimental gene targeting methodology, these data have important implications for studying IgE-reactions in mouse systems.

Asunto(s)

Anafilaxia/inmunología , Inmunoglobulina E/inmunología , Mastocitos/inmunología , Ovalbúmina/inmunología , Anafilaxia/etiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/inmunología , Temperatura Corporal/efectos de los fármacos , Temperatura Corporal/inmunología , Degranulación de la Célula/inmunología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Citometría de Flujo , Histamina/administración & dosificación , Histamina/inmunología , Inmunoglobulina G/inmunología , Interleucina-3/farmacología , Masculino , Mastocitos/metabolismo , Mastocitos/fisiología , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos BALB C , Ovalbúmina/administración & dosificación , Proteínas Proto-Oncogénicas c-kit/metabolismo , Receptores de IgE/metabolismo

RESUMEN

Traumatic brain injury (TBI) is a highly complex multi-factorial disorder. Animal models of TBI are used to elucidate primary and secondary injury mechanisms and pathophysiological changes and to provide the diagnostic and therapeutical basis for TBI. The choices of animal models depend upon the research objectives. However, various animal models have limitations. The models only can duplicate the pivotal injury mechanisms or a certain important pathophysiological course. The characteristics of human TBI can not fully be reflected by using these models. In the review, animal models of traumatic brain injury are classified as dynamic direct brain injury, indirect dynamic brain injury and combined neuro-traumatic models. Several common models are described for consideration.

Asunto(s)

Animales , Humanos , Ratones , Ratas , Fenómenos Biomecánicos , Encéfalo/fisiopatología , Lesiones Encefálicas/fisiopatología , Lesión Axonal Difusa/fisiopatología , Modelos Animales de Enfermedad , Medicina Legal , Traumatismos Cerrados de la Cabeza/fisiopatología , Traumatismos Penetrantes de la Cabeza/fisiopatología , Reproducibilidad de los Resultados

RESUMEN

OBJECTIVE: To provide objective proof on diagnosis of electrical current mark in electrocution, the environmental scanning electron microscopy and energy dispersive X-ray microanalyser (ESEM-EDX) were adopted to study the microscopic morphological characteristics and elemental composition of electrical current mark. METHODS: Morphological characteristics of electrical current marks, the elemental composition and morphology of metal particles were studied with ESEM-EDX. RESULTS: The electroporation and metal melted beads could be found in the electrical current marks and skin around them. The metal melted beads mainly composed of common metal such as iron, copper, aluminum and some uncommon metal including gold, titanium and barium. CONCLUSION: ESEM-EDX can be applied in forensic diagnosis of electrocution.

Asunto(s)

Traumatismos por Electricidad/diagnóstico , Microanálisis por Sonda Electrónica/métodos , Microscopía Electrónica de Rastreo/métodos , Piel/patología , Autopsia , Traumatismos por Electricidad/patología , Medicina Legal/métodos , Humanos , Metales Pesados/análisis , Piel/química , Piel/lesiones , Oligoelementos/análisis , Rayos X