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1.
J Physiol Pharmacol ; 75(2): 173-183, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38736264

RESUMEN

Quercetin is widely distributed in plants as a flavonol compound with multiple biological activities. It has been found that quercetin can regulate bone homeostasis through multiple pathways and targets. This study investigated the role and specific molecular mechanisms of quercetin in regulating osteoblast viability, proliferation, migration and osteogenic differentiation. A mouse model of traumatic fracture was established and then 100 mg/kg quercetin corn oil suspension was gavaged at the same time every day for 28 days. miR-6089 and E2F transcription factor 2 (E2F2) expression levels in mice were measured. Fracture healing in mice was observed. MC3T3-E1 cells were transfected with plasmids targeting miR-6089 and E2F2, and cell viability, proliferation, migration, apoptosis, and osteogenic differentiation were determined. The targeting relationship between miR-6089 and E2F2 was verified. In vivo experiments showed that quercetin significantly increased osteocalcin (OCN) expression (P<0.05) and promoted fracture healing in traumatic fracture (TF) mice. miR-6089 expression was down-regulated (P<0.05) and E2F2 expression was up-regulated (P<0.05) in TF mice. Quercetin promoted miR-6089 expression and inhibited E2F2 expression (both P<0.05). In vitro results showed that quercetin promoted miR-6089 expression and inhibited E2F2 expression in a dose-dependent manner (both P<0.05). Quercetin dose-dependently promoted MC3T3-E1 cell viability, proliferation, migration, and osteogenic differentiation, and inhibited MC3T3-E1 cell apoptosis (all P<0.05). Up-regulating miR-6089 further promoted MC3T3-E1 cell viability, proliferation, migration and osteogenic differentiation, and inhibited MC3T3-E1 cell apoptosis (all P<0.05). miR-6089 targeted and regulated E2F2 expression. Up-regulating E2F2 attenuated the promoting effect of up-regulated miR-6089 on MC3T3-E1 cell viability, proliferation, migration, osteogenic differentiation, and inhibition of apoptosis (all P<0.05). We conclude that quercetin enhances osteoblast viability, proliferation, migration, and osteogenic differentiation by modulating the miR-6089/E2F2 axis, thereby promoting fracture healing.


Asunto(s)
Factor de Transcripción E2F2 , Curación de Fractura , MicroARNs , Osteoblastos , Osteogénesis , Quercetina , Animales , Masculino , Ratones , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Factor de Transcripción E2F2/metabolismo , Factor de Transcripción E2F2/genética , Curación de Fractura/efectos de los fármacos , MicroARNs/genética , MicroARNs/metabolismo , Osteoblastos/efectos de los fármacos , Osteoblastos/metabolismo , Osteogénesis/efectos de los fármacos , Quercetina/farmacología
2.
J Vet Intern Med ; 27(1): 126-33, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23205923

RESUMEN

BACKGROUND: Cisplatin combined with a nonselective cyclooxygenase (cox) inhibitor has potent antitumor activity against transitional cell carcinoma (TCC) in dogs, but this treatment is limited by renal toxicosis. Cox-2 is expressed in TCC, but only in limited sites within the kidney. A cox-2 inhibitor could enhance the antitumor activity of cisplatin with potentially fewer adverse effects on the kidney. HYPOTHESIS: Cisplatin/cox-2 inhibitor treatment will have greater antitumor activity but no more renal toxicosis than cisplatin alone in dogs with TCC. ANIMALS: Forty-four dogs with naturally occurring urinary bladder TCC. METHODS: Dogs were randomized to receive cisplatin (60 mg/m(2) IV q21d), firocoxib (5 mg/kg PO q24h), or the combination. Tumor measurements were determined before and at 6-week intervals during treatment. Renal function was monitored by serum creatinine concentration, iohexol clearance, and urine specific gravity. Toxicoses were graded according to Veterinary Co-Operative Oncology Group (VCOG) criteria. RESULTS: The remission rate with cisplatin/firocoxib (57%) was significantly (P = .021) higher than that with cisplatin alone (13%). Renal and gastrointestinal toxicoses were common in dogs receiving cisplatin, but there were no significant differences between dogs receiving cisplatin or cisplatin/firocoxib. Firocoxib alone induced partial remission or stable disease in 20 and 33% of dogs, respectively. CONCLUSIONS: Firocoxib significantly enhanced the antitumor activity of cisplatin resulting in partial remission in more than half of the cases. The toxicoses inherent to cisplatin, however, were noted in dogs receiving this combination. Firocoxib had antitumor effects as a single agent and can be considered a palliative treatment for dogs with TCC.


Asunto(s)
4-Butirolactona/análogos & derivados , Antineoplásicos/uso terapéutico , Carcinoma de Células Transicionales/veterinaria , Cisplatino/uso terapéutico , Enfermedades de los Perros/tratamiento farmacológico , Sulfonas/uso terapéutico , Neoplasias de la Vejiga Urinaria/veterinaria , 4-Butirolactona/administración & dosificación , 4-Butirolactona/efectos adversos , 4-Butirolactona/uso terapéutico , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/efectos adversos , Carcinoma de Células Transicionales/tratamiento farmacológico , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Enfermedades de los Perros/inducido químicamente , Perros , Quimioterapia Combinada , Femenino , Enfermedades Gastrointestinales/inducido químicamente , Enfermedades Gastrointestinales/veterinaria , Masculino , Calidad de Vida , Sulfonas/administración & dosificación , Sulfonas/efectos adversos , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico
3.
Ir Med J ; 105(8): 271-4, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23155914

RESUMEN

Studies suggest older adults attending emergency departments(ED) benefit from specialist geriatric medicine evaluation. Findings from a pilot ED Geriatric Medicine(GM) liaison service in our 480-bed university hospital are presented. This is not a randomized controlled trial. Service comprised consultant geriatrician and senior trainee-led sessions during daytime working hours. Senior ED personnel selected appropriate patients. GM service also took over ED medical admissions aged 80, 1 in 9 days from General Internal Medicine(GIM). 49% of 284 patients (83.5 +/- 6.8 years) referred, were discharged from ED with appropriate follow-up. Inpatient analysis comprised 51% admitted to GIM, GM and specialist services as per on-call rota and 268 patients taken over from GIM. Patients under GM had shorter length of stay (p < 0.001). The findings suggest specialty specific geriatric medicine management of the older adult presenting to ED can improve service and patient outcomes.


Asunto(s)
Servicio de Urgencia en Hospital/organización & administración , Geriatría , Admisión del Paciente , Anciano , Anciano de 80 o más Años , Femenino , Evaluación Geriátrica , Humanos , Medicina Interna , Masculino
4.
Biomed Opt Express ; 3(8): 1947-54, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22876357

RESUMEN

Transbronchial needle aspiration (TBNA) is a procedure routinely performed to diagnose peripheral pulmonary lesions. However, TBNA is associated with a low diagnostic yield due to inappropriate needle placement. We have developed a flexible transbronchial optical frequency domain imaging (TB-OFDI) catheter that functions as a "smart needle" to confirm the needle placement within the target lesion prior to biopsy. The TB-OFDI smart needle consists of a flexible and removable OFDI catheter (430 µm dia.) that operates within a standard 21-gauge TBNA needle. The OFDI imaging core is based on an angle polished ball lens design with a working distance of 160 µm from the catheter sheath and a spot size of 25 µm. To demonstrate the potential of the TB-OFDI smart needle for transbronchial imaging, an inflated excised swine lung was imaged through a standard bronchoscope. Cross-sectional and longitudinal OFDI results reveal the detailed network of alveoli in the lung parenchyma suggesting that the TB-OFDI smart needle may be a useful tool for guiding biopsy acquisition to increase the diagnostic yield.

5.
J Vet Intern Med ; 25(6): 1385-90, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22092632

RESUMEN

BACKGROUND: Transitional cell carcinoma (TCC) of the urinary bladder of dogs can be a difficult cancer to treat, and effective therapies are limited. Vinblastine has been used in humans with TCC and has potent anti-proliferative effects against canine TCC cells in vitro. OBJECTIVES: To determine the antitumor activity and toxicoses of vinblastine in dogs with urinary bladder TCC. ANIMALS: Animals selected were 28 privately owned dogs that presented to the Purdue University Veterinary Teaching Hospital (PUVTH) with measurable, histologically confirmed TCC. METHODS: Prospective clinical trial: The starting vinblastine dosage was 3.0 mg/m(2) i.v. every 2 weeks. Treatment continued until cancer progression or unacceptable toxicoses occurred. Complete evaluations (physical exam, complete blood count [CBC], serum biochemical profile, urinalysis, thoracic radiography, abdominal ultrasound [US]) were performed at 8-week intervals. Urinary tract US with bladder tumor mapping was performed monthly. Toxicoses were graded according to Veterinary Co-Operative Oncology Group (VCOG) criteria. RESULTS: Tumor responses included 10 (36%) partial remission, 14 (50%) stable disease, and 4 (14%) progressive disease. The median progression free interval was 122 days (range, 28-399 days). The median survival time was 147 days (range, 28-476 days) from 1st vinblastine treatment to death and 299 days (range, 43-921 days) from diagnosis to death. The majority of dogs (27 of 28) did not have clinically relevant adverse effects. Seventeen of 28 (61%) dogs required dosage reductions because of neutropenia. CONCLUSION AND CLINICAL IMPORTANCE: Vinblastine has antitumor activity against TCC in dogs and can be considered another treatment option for this cancer.


Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Carcinoma de Células Transicionales/veterinaria , Enfermedades de los Perros/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/veterinaria , Vinblastina/uso terapéutico , Animales , Carcinoma de Células Transicionales/tratamiento farmacológico , Línea Celular Tumoral , Perros , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico
6.
Ir J Med Sci ; 180(1): 41-5, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20665122

RESUMEN

BACKGROUND: Stroke can affect a person's ability to drive, an important means of transportation in the developed world. AIMS: To determine percentage of patients and factors associated with return to driving post-stroke in a service with emphasis on driver assessment. METHODS: Retrospective study of patients discharged from the Stroke Service of our 470-bed teaching hospital from 1998 to 2002. RESULTS: Of 72 drivers pre-stroke, 54% recalled a driving assessment and 68% returned to driving. Younger patients (58.6 ± 12.0 vs. 66.5 ± 10.5, p = 0.008) with lower Modified Rankin Score (median 1 vs. 2, p = 0.0001) and normal cognition (55 vs. 43%, p = 0.45) were more likely to resume driving. More patients who were assessed returned to driving than those who were not (74 vs. 61%, p = 0.31). CONCLUSIONS: A relatively high level of return to driving can be achieved post-stroke with a pro-active approach to driver assessment and rehabilitation. A structured assessment and referral programme should be offered where appropriate.


Asunto(s)
Conducción de Automóvil , Rehabilitación de Accidente Cerebrovascular , Adulto , Anciano , Anciano de 80 o más Años , Conducción de Automóvil/estadística & datos numéricos , Femenino , Humanos , Irlanda , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
7.
Opt Express ; 18(8): 7642-9, 2010 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-20588604

RESUMEN

We report a novel fiber probe based Raman detection system on a microfluidic platform where a split Raman probe is directly embedded into a polydimethylsiloxane (PDMS) chip. In contrast to previous Raman detection schemes in microfluidics, probe based detection offers reduced background and portability. Compared to conventional backscattering probe designs, the split fiber probe we used in this system, results in a reduced size and offers flexibility to modify the collection geometry to minimize the background generated by the fibers. Also our microfluidic chip design enables us to obtain an alignment free system. As a proof of concept we demonstrate the sensitivity of the device for urea detection at relevant human physiological levels with a low acquisition time. The development of this system on a microfluidic platform means portable, lab on a chip devices for biological analyte detection and environmental sensing using Raman spectroscopy are now within reach.


Asunto(s)
Microfluídica/instrumentación , Microfluídica/métodos , Fibras Ópticas , Espectrometría Raman/instrumentación , Espectrometría Raman/métodos , Etanol/análisis , Límite de Detección , Reología , Factores de Tiempo , Urea/análisis
8.
Case Rep Med ; 2010: 549258, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21209814

RESUMEN

WE DESCRIBE AN UNUSUAL COMPLICATION OF A COMMON DISEASE: stroke presenting in a man recently diagnosed with polymyalgia rheumatica. Initial inflammatory markers were misleading. We discuss pitfalls in diagnosis, and approach to management.

9.
Opt Express ; 17(4): 2375-84, 2009 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-19219141

RESUMEN

Common-path optical coherence tomography (CPOCT) is known to reduce group velocity dispersion and polarization mismatch between the reference and the sample arm as both arms share the same physical path. Existing implementations of CPOCT typically require one to incorporate an additional cover glass within the beam path of the sample arm to provide a reference signal. In this paper, we aim to further reduce this step by directly making use of the back-reflected signal, arising from a conical lens-tip fiber, as a reference signal. The conical lens, which is directly manufactured onto the optical fiber tip via a simple selective-chemical etching process, fulfils two functions acting as both the imaging lens and the self-aligning reference plane. We use a Fourier-domain OCT system to demonstrate the feasibility of this technique upon biological tissue. An in-fiber CPOCT technique may prove potentially useful in endoscopic OCT imaging.


Asunto(s)
Endoscopía , Tecnología de Fibra Óptica/instrumentación , Aumento de la Imagen/instrumentación , Tomografía de Coherencia Óptica/instrumentación , Transductores , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Neurology ; 70(20): 1883-90, 2008 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-18474843

RESUMEN

OBJECTIVE: To document neurologic, oncologic, and serologic associations of patients in whom voltage-gated potassium channel (VGKC) autoantibodies were detected in the course of serologic evaluation for neuronal, glial, and muscle autoantibodies. METHODS: Indirect immunofluorescence screening of sera from 130,000 patients performed on a service basis for markers of paraneoplastic neurologic autoimmunity identified 80 patients whose IgG bound to the synapse-rich molecular layer of mouse cerebellar cortex in a pattern consistent with VGKC immunoreactivity. Antibody specificity was confirmed in all cases by immunoprecipitation of detergent-solubilized brain synaptic proteins complexed with (125)I-alpha-dendrotoxin. RESULTS: Clinical information was available for 72 patients: 51% women, median age at symptom onset 65 years, and median follow-up period 14 months. Neurologic manifestations were acute to subacute in onset in 71% and multifocal in 46%; 71% had cognitive impairment, 58% seizures, 33% dysautonomia, 29% myoclonus, 26% dyssomnia, 25% peripheral nerve dysfunction, 21% extrapyramidal dysfunction, and 19% brainstem/cranial nerve dysfunction. Creutzfeldt-Jakob disease was a common misdiagnosis (14%). Neoplasms encountered (confirmed histologically in 33%) included 18 carcinomas, 5 adenomas, 1 thymoma, and 3 hematologic malignancies. Hyponatremia was documented in 36%, other organ-specific autoantibodies in 49%, and a co-existing autoimmune disorder in 33% (including thyroiditis 21%, type 1 diabetes mellitus 11%). Benefit was reported for 34 of 38 patients (89%) receiving immunotherapy and was marked in 50%. CONCLUSIONS: The spectrum of neurologic manifestations and neoplasms associated with voltage-gated potassium channel (VGKC) autoimmunity is broader than previously recognized. Evaluation for VGKC antibodies is recommended in the comprehensive autoimmune serologic testing of subacute idiopathic neurologic disorders.


Asunto(s)
Autoanticuerpos/sangre , Síndromes Paraneoplásicos/inmunología , Enfermedades del Sistema Nervioso Periférico/inmunología , Canales de Potasio de la Superfamilia Shaker/inmunología , Adenoma/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades del Sistema Nervioso Autónomo/etiología , Enfermedades del Sistema Nervioso Autónomo/inmunología , Enfermedades de los Ganglios Basales/etiología , Enfermedades de los Ganglios Basales/inmunología , Niño , Enfermedades de los Nervios Craneales/etiología , Enfermedades de los Nervios Craneales/inmunología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Neoplasias Hematológicas/complicaciones , Humanos , Canal de Potasio Kv.1.1/inmunología , Canal de Potasio Kv.1.2/inmunología , Canal de Potasio Kv1.6 , Masculino , Persona de Mediana Edad , Mioclonía/etiología , Mioclonía/inmunología , Síndromes Paraneoplásicos/complicaciones , Enfermedades del Sistema Nervioso Periférico/etiología , Timoma/complicaciones , Neoplasias del Timo/complicaciones
11.
Ir J Med Sci ; 176(2): 75-9, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17447105

RESUMEN

BACKGROUND: In 2002, a survey of stroke management was conducted in our institution benchmarked against the UK National Stroke Audit 2002. The conclusion was that management of stroke patients lacked organised and specialised care. The introduction of a stroke care pathway was recommended. AIMS: This audit assessed the clinical impact of implementation of a stroke care pathway by the general medical teams in an acute teaching hospital. METHODS: A random sample of 48/131 patients were surveyed in 2002 compared to 55 consecutive patients admitted with stroke in 2005. RESULTS: Despite introduction of a stroke care pathway, marked deficits persisted in acute management including delays in brain imaging and aspirin administration, assessment of acute parameters and interdisciplinary care. CONCLUSIONS: Optimal care of stroke patients cannot be achieved by introducing a stroke care pathway alone. We recommend the urgent establishment of a stroke unit with a specialist consultant-led multidisciplinary stroke team.


Asunto(s)
Vías Clínicas , Hospitales de Enseñanza/normas , Auditoría Médica , Grupo de Atención al Paciente/normas , Accidente Cerebrovascular/terapia , Anciano , Benchmarking , Femenino , Humanos , Irlanda , Masculino , Rehabilitación de Accidente Cerebrovascular
12.
Ir J Med Sci ; 174(3): 28-31, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16285335

RESUMEN

BACKGROUND: Patient falls are a common complication of hospitalisation. Use of restraints in patients who are perceived to be at risk for falling may lead to injury and even death. AIMS: To determine the frequency of falls and fall-related injuries and the contribution of restraints in a hospital population. METHODS: We analysed incident reports of falls for a single year from a large teaching hospital. Results The fall rate per 10,000 patient days was 13.2 (95%CI 11.6-14.8). Fall rate increased dramatically with increased age. Eighty-two (30.7%) falls resulted in injury, of which 6 (7.3%) were serious. Injuries occurred in 71/247 (29%) unrestrained falls and in 11/20 (55%) falls in patients who were restrained. Injuries were more severe in falls with restraints in place (p < 0.0001). CONCLUSIONS: Restraint use is associated with increased severity of injury in hospital patients who fall.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Hospitales de Enseñanza/estadística & datos numéricos , Restricción Física/estadística & datos numéricos , Accidentes por Caídas/prevención & control , Enfermedad Aguda , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Lechos , Diseño de Equipo , Femenino , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Masculino , Persona de Mediana Edad , Restricción Física/efectos adversos , Restricción Física/instrumentación , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo
13.
Ir J Med Sci ; 174(1): 49-54, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15868890

RESUMEN

BACKGROUND: When worn external Hip Protectors (EHP) reduce hip fracture but poor compliance results in reduced efficacy. AIMS: We determined the compliance with EHP therapy among a group of elderly people attending a day hospital. METHODS: Forty-five patients or their care-givers were interviewed a mean (sd) 334 (150) days after they had been given EHP. RESULTS: There were 12 men and 33 women with mean age of 80 (7) years. Only ten (22%) were still wearing EHP properly. Those who were compliant were given their EHP more recently than those who were not (277 (118) days vs 403 (159), p = 0.0062) and were more likely to feel safer when wearing them (p = 00.017, chi2= 5.68). Reasons for non-compliance included exclusive outdoor wear, discomfort and inconvenience. CONCLUSIONS: Hip protector compliance was poor in this small study of elderly individuals attending a day hospital. Better patient education may improve compliance though this needs to be determined.


Asunto(s)
Centros de Día , Fracturas de Cadera/prevención & control , Cooperación del Paciente/estadística & datos numéricos , Equipos de Seguridad/estadística & datos numéricos , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Centros de Día/estadística & datos numéricos , Femenino , Hospitales/estadística & datos numéricos , Humanos , Entrevistas como Asunto , Masculino , Cooperación del Paciente/psicología , Estudios Prospectivos , Diseño de Prótesis , Factores de Tiempo
15.
J Clin Neurosci ; 8(5): 404-6, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11535004

RESUMEN

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leucoencephalopathy (CADASIL) is a recently described cause of stroke or stroke-like episodes. It is caused by mutations in the Notch3 gene on chromosome 19p. We sought to demonstrate mutations of the Notch3 gene in Australian patients suspected of having CADASIL. Patients from several families were referred to the study. A diagnosis was determined clinically and by neuroimaging. Those suspected of having CADASIL had sequencing of exons 3 and 4 of the Notch3 gene. Eight patients, two of whom were siblings, were suspected of having CADASIL. Five patients (including the siblings) had mutations. Because of strong clustering of Notch3 mutations in CADASIL, this has potential as a reliable test for the disease in Australian patients.


Asunto(s)
Demencia por Múltiples Infartos/genética , Proteínas Proto-Oncogénicas/genética , Receptores de Superficie Celular , Anciano , Australia , Demencia por Múltiples Infartos/diagnóstico por imagen , Exones , Genotipo , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Mutación Puntual , Radiografía , Receptor Notch3 , Receptores Notch
16.
J Biol Chem ; 276(47): 44193-202, 2001 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-11559703

RESUMEN

In Caenorhabditis elegans, fem-1, fem-2, and fem-3 play pivotal roles in sex determination. Recently, a mammalian homologue of the C. elegans sex-determining protein FEM-1, F1Aalpha, has been described. Although there is little evidence to link F1Aalpha to sex determination, F1Aalpha and FEM-1 both promote apoptosis in mammalian cells. Here we report the identification and characterization of a human homologue of the C. elegans sex-determining protein FEM-2, hFEM-2. Similar to FEM-2, hFEM-2 exhibited PP2C phosphatase activity and associated with FEM-3. hFEM-2 shows striking similarity (79% amino acid identity) to rat Ca(2+)/calmodulin (CaM)-dependent protein kinase phosphatase (rCaMKPase). hFEM-2 and FEM-2, but not PP2Calpha, were demonstrated to dephosphorylate CaM kinase II efficiently in vitro, suggesting that hFEM-2 and FEM-2 are specific phosphatases for CaM kinase. Furthermore, hFEM-2 and FEM-2 associated with F1Aalpha and FEM-1 respectively. Overexpression of hFEM-2, FEM-2, or rCaMKPase all mediated apoptosis in mammalian cells. The catalytically active, but not the inactive, forms of hFEM-2 induced caspase-dependent apoptosis, which was blocked by Bcl-XL or a dominant negative mutant of caspase-9. Taken together, our data suggest that hFEM-2 and rCaMKPase are mammalian homologues of FEM-2 and they are evolutionarily conserved CaM kinase phosphatases that may have a role in apoptosis signaling.


Asunto(s)
Apoptosis , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Proteínas del Helminto/metabolismo , Fosfoproteínas Fosfatasas , Secuencia de Aminoácidos , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Línea Celular , Proteínas del Helminto/química , Humanos , Ratones , Datos de Secuencia Molecular , Fosforilación , Homología de Secuencia de Aminoácido
17.
J Biol Chem ; 276(4): 2802-7, 2001 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-11060313

RESUMEN

A novel Bax-associating protein, named MAP-1 (Modulator of Apoptosis), has been identified in a yeast two-hybrid screen. MAP-1 contains a BH3-like (BH: Bcl-2 homology) motif and mediates caspase-dependent apoptosis in mammalian cells when overexpressed. MAP-1 homodimerizes and associates with the proapoptotic Bax and the prosurvival Bcl-2 and Bcl-X(L) of the Bcl-2 family in vitro and in vivo in mammalian cells. Mutagenesis analyses revealed that the BH3-like domain in MAP-1 is not required for its association with Bcl-X(L) but is required for association with Bax and for mediating apoptosis. Interestingly, in contrast to other Bax-associating proteins such as Bcl-X(L) and Bid, which require the BH3 and BH1 domains of Bax, respectively, for binding, the binding of MAP-1 to Bax appears to require all three BH domains (BH1, BH2, and BH3) of Bax, because point mutation of the critical amino acid in any one of these domains is sufficient to abolish its binding to MAP-1. These data suggest that MAP-1 mediates apoptosis through a mechanism that involves binding to Bax.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Apoptosis , Proteínas Portadoras/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis , Sitios de Unión , Proteínas Portadoras/genética , Caspasas/metabolismo , Secuencia Conservada , Dimerización , Humanos , Ratones , Datos de Secuencia Molecular , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Homología de Secuencia de Aminoácido , Proteína X Asociada a bcl-2
18.
J Biol Chem ; 275(24): 17925-8, 2000 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-10764728

RESUMEN

Sex-specific elimination of cells by apoptosis plays a role in sex determination in Caenorhabditis elegans. Recently, a mammalian pro-apoptotic protein named F1Aalpha has been identified. F1Aalpha shares extensive homology throughout the entire protein with the C. elegans protein, FEM-1, which is essential for achieving all aspects of the male phenotype in the nematode. In this report, the role of FEM-1 in apoptosis was investigated. Overexpression of FEM-1 induces caspase-dependent apoptosis in mammalian cells. FEM-1 is cleaved in vitro by the C. elegans caspase, CED-3, generating an N-terminal cleavage product that corresponds to the minimal effector domain for apoptosis. Furthermore, CED-4 associates with FEM-1 in vitro and in vivo in mammalian cells and potentiates FEM-1-mediated apoptosis. Similarly, Apaf-1, the mammalian homologue of CED-4 was found to associate with F1Aalpha. These data suggest that FEM-1 and F1Aalpha may mediate apoptosis by communicating directly with the core machinery of apoptosis.


Asunto(s)
Apoptosis , Proteínas de Caenorhabditis elegans , Caenorhabditis elegans/metabolismo , Proteínas de Unión al Calcio/metabolismo , Caspasas , Proteínas de Ciclo Celular/metabolismo , Cisteína Endopeptidasas/metabolismo , Proteínas del Helminto/metabolismo , Animales , Línea Celular , Humanos , Cinética , Masculino , Unión Proteica , Homología de Secuencia de Aminoácido
19.
J Biol Chem ; 274(34): 23687-90, 1999 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-10446124

RESUMEN

Upon activation of the Fas apoptotic signaling pathway, Bid, a "BH3 domain-only" pro-apoptotic molecule, is cleaved by caspase-8 into a 6.5-kDa N-terminal and a 15-kDa BH3 domain-containing C-terminal fragment, referred to as t(n)-Bid and t(c)-Bid, respectively. t(c)-Bid is a more potent inducer of apoptosis than full-length Bid, suggesting that the N-terminal region of Bid has an inhibitory effect on its pro-apoptotic activity. Here, we report the identification of a novel BH3-like motif (amino acid residues 35-43) in t(n)-Bid. Although Bid does not homodimerize, t(n)-Bid is able to associate avidly with t(c)-Bid. Site-directed mutagenesis revealed that both the novel BH3-like and BH3 domains are necessary for direct binding between t(n)-Bid and t(c)-Bid. While full-length Bid does not associate with t(n)-Bid, substitution of Leu(35), a critical residue in mediating t(n)-Bid/t(c)-Bid interaction, with Ala in full-length Bid is sufficient to establish Bid/t(n)-Bid interaction. Interestingly, the L35A Bid mutant is as effective as t(c)-Bid in inducing apoptosis and binding Bcl-X(L). We propose that the intramolecular interaction involving the BH3-like and BH3 domains serves to regulate the pro-apoptotic potential of Bid.


Asunto(s)
Apoptosis , Proteínas Portadoras/química , Secuencia de Aminoácidos , Proteína Proapoptótica que Interacciona Mediante Dominios BH3 , Proteínas Portadoras/fisiología , Relación Estructura-Actividad
20.
Clin Lab Haematol ; 20(4): 239-44, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9777271

RESUMEN

Carnosine and anserine, the bioactive peptides found in most meats and fish, were tested for their ability to modulate neutrophil and U937 cell function, specifically with respect to respiratory burst, interleukin-1 beta production and apoptosis. Both peptides increased the respiratory burst and interleukin-1 beta production of human neutrophils but not of U937 cells. They suppressed apoptosis of human neutrophils but enhanced apoptosis of U937 cells as assessed by DNA strand breaks. These results suggest that carnosine and anserine have the capacity to modulate the immune response at least in human neutrophils.


Asunto(s)
Anserina/farmacología , Carnosina/farmacología , Neutrófilos/fisiología , Apoptosis/efectos de los fármacos , Humanos , Interleucina-1/biosíntesis , Neutrófilos/efectos de los fármacos , Estallido Respiratorio/efectos de los fármacos , Superóxidos/metabolismo , Células U937/efectos de los fármacos
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