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1.
J Biomed Mater Res A ; 110(4): 747-760, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34713570

RESUMEN

Recently, we have developed a hydroxyapatite (HAp)-hybridized double-network (DN) hydrogel (HAp/DN gel), which can robustly bond to the bone tissue in the living body. The purpose of this study is to clarify whether the HAp/DN gel surface can differentiate the bone marrow-derived mesenchymal stem cells (MSCs) to osteogenic cells. We used the MSCs which were harvested from the rabbit bone marrow and cultured on the polystyrene (PS) dish using the autogenous serum-supplemented medium. First, we confirmed the properties of MSCs by evaluating colony forming unit capacity, expression of MSC markers using flow cytometry, and multidifferential capacity. Secondly, polymerase chain reaction analysis demonstrated that the HAp/DN gel surface significantly enhanced mRNA expression of the eight osteogenic markers (TGF-ß1, BMP-2, Runx2, Col-1, ALP, OPN, BSP, and OCN) in the cultured MSCs at 7 days than the PS surfaces (p < 0.0001), while the DN gel and HAp surfaces provided no or only a slight effect on the expression of these markers except for Runx2. Additionally, the alkaline phosphatase activity was significantly higher in the cells cultured on the HAp/DN gel surface than in the other three material surfaces (p < 0.0001). Thirdly, when the HAp/DN gel plug was implanted into the rabbit bone marrow, MSC marker-positive cells were recruited in the tissue generated around the plug at 3 days, and Runx2 and OCN were highly expressed in these cells. In conclusion, this study demonstrated that the HAp/DN gel surface can differentiate the MSCs into osteogenic cells.


Asunto(s)
Durapatita , Células Madre Mesenquimatosas , Animales , Médula Ósea/metabolismo , Células de la Médula Ósea/metabolismo , Diferenciación Celular/genética , Células Cultivadas , Durapatita/química , Hidrogeles/metabolismo , Hidrogeles/farmacología , Osteogénesis/genética , Conejos
2.
BMJ Open ; 9(5): e025389, 2019 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-31122968

RESUMEN

INTRODUCTION: The phenomenon of population ageing is accompanied by increases in the number of elderly haemodialysis patients worldwide. The incidence of frailty is high in the haemodialysis population and is associated with poor clinical outcome. Although several interventions have been developed for use in general haemodialysis patients, the efficacy of such rehabilitation programmes in frail elderly patients on haemodialysis has not been elucidated. Here, we examined whether electrical muscle stimulation (EMS) would show beneficial effects in frail elderly patients on haemodialysis. METHODS AND ANALYSIS: This is a randomised, two-period, controlled crossover trial, which will enrol 20 patients. Haemodialysis patients aged ≥65 years and defined as frail (ie, Short Physical Performance Battery score 4-9), will be randomly assigned to either group 1 (EMS intervention beginning in treatment period I, followed by reallocation as controls in treatment period II after a 5-week washout period) or group 2 (opposite schedule) in a 1:1 ratio. The two intervention periods will last 5 weeks each with an intervening washout period of 5 weeks. In the EMS intervention group, the treatment will be applied to the skeletal muscle of the entire lower extremity for 5 weeks, three times/week for 30-40 min during haemodialysis. The primary outcome of this study is the change in quadriceps isometric strength after the interventions. The secondary outcomes are the changes in physical function, physical activity, difficulty in activities of daily living, body composition, cognitive function, depressive symptoms, quality of life, blood test results and the clinical safety and feasibility of EMS therapy. ETHICS AND DISSEMINATION: This study has been approved by the institutional review board/ethics committee of Kitasato University Allied Health Sciences. This study will be reported in peer reviewed publications and at conference presentations. TRIAL REGISTRATION NUMBER: UMIN000032501.


Asunto(s)
Terapia por Estimulación Eléctrica , Tolerancia al Ejercicio/fisiología , Anciano Frágil/psicología , Extremidad Inferior/fisiopatología , Músculo Esquelético/fisiopatología , Diálisis Renal , Actividades Cotidianas/psicología , Anciano , Anciano de 80 o más Años , Estudios Cruzados , Femenino , Humanos , Masculino , Calidad de Vida , Diálisis Renal/psicología
3.
J Neurol Surg A Cent Eur Neurosurg ; 80(1): 53-57, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29972856

RESUMEN

BACKGROUND: It is very rare for a choroid plexus tumor to occur intraparenchymally in the absence of a relation to the choroid plexus. CLINICAL PRESENTATION: A case of cerebral intraparenchymal choroid plexus tumor in a 30-year-old woman presenting with left hemiparesis is described. Brain magnetic resonance imaging depicted a large cystic mass in the right frontal lobe. Tumor resection was performed by right frontal craniotomy. No connection with the choroid plexus was observed during the operation. Histologically, the tumor exhibited a glandular structure with a papillary pattern suggesting a neoplasm of epithelial origin. Immunohistochemical analyses revealed the tumor as an atypical choroid plexus papilloma. CONCLUSION: Immunohistochemical findings, especially regarding Kir7.1, are very important for the differential diagnosis of cerebral intraparenchymal choroid plexus tumors from metastatic tumors. The present case reveals that an atypical choroid plexus papilloma can occur intraparenchymally without an association with the choroid plexus. Intraparenchymal atypical choroid plexus papillomas may have previously been diagnosed incorrectly as metastatic adenocarcinomas of unknown origin.


Asunto(s)
Papiloma del Plexo Coroideo/diagnóstico , Papiloma del Plexo Coroideo/metabolismo , Adulto , Craneotomía , Diagnóstico Diferencial , Femenino , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/patología , Humanos , Imagen por Resonancia Magnética , Papiloma del Plexo Coroideo/cirugía , Canales de Potasio de Rectificación Interna/metabolismo
4.
Clin Cardiol ; 40(12): 1189-1196, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29247531

RESUMEN

In elderly patients with acute heart failure (AHF), clinical outcome is adversely affected by frailty. Although a number of potentially effective interventions for frailty have been reported, little is known about the effects of rehabilitation programs in frail elderly AHF patients. We postulated that addition of electrical muscle stimulation (EMS), which induces muscle contraction without requiring patient volition, to early rehabilitation would be efficacious in frail elderly AHF patients. The ACTIVE-EMS (Effects of Acute Phase Intensive Electrical Muscle Stimulation in Frail Elderly Patients With AHF; UMIN000019551) trial is a multicenter, randomized controlled trial that will enroll 80 patients from 3 hospitals in Japan. AHF patients age ≥ 75 years positive for frailty, defined as Short Physical Performance Battery score 4 to 9, will be randomly assigned to receive early rehabilitation program only or EMS add-on therapy for 2 weeks. The primary endpoint of the trial is the change in quadriceps isometric strength between baseline and 2 weeks, with changes in physical function and cognitive function, and clinical safety and feasibility of EMS therapy as secondary outcomes. ACTIVE-EMS is the first randomized trial to evaluate the clinical effectiveness of adding EMS therapy to early rehabilitation in frail elderly AHF patients. The results of this study will provide insight for the development of appropriate rehabilitation programs for this high-risk population.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Anciano Frágil/estadística & datos numéricos , Insuficiencia Cardíaca/rehabilitación , Actividad Motora/fisiología , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Salud Global , Insuficiencia Cardíaca/epidemiología , Humanos , Masculino , Prevalencia , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento
5.
Int Heart J ; 57(6): 676-681, 2016 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-27818472

RESUMEN

This study aimed to investigate whether a single session of neuromuscular electrical stimulation (NMES) can enhance vascular endothelial function and peripheral blood circulation in patients with acute myocardial infarction (AMI). Thirty-four male patients with AMI were alternately assigned to 2 groups, and received NMES with muscle contraction (NMES group, n = 17) or without muscle contraction (control group, n = 17) after admission. NMES was performed for quadriceps and gastrocnemius muscles of both legs for 30 minutes. We measured systolic blood pressure as a parameter of cardiovascular responses and the low-frequency component of blood pressure variability as an index of sympathetic activity. Reactive hyperemia peripheral arterial tonometry (RH-PAT) index and transcutaneous oxygen pressure in foot (Foot-tcPO2) were also measured as parameters of vascular endothelial function and peripheral blood circulation, respectively. All patients completed the study without severe adverse events. Systolic blood pressure and the low-frequency component increased significantly during the NMES session in both groups (P < 0.01 and P < 0.05, respectively). However, elevation from systolic blood pressure at rest was < 10 mmHg in both groups. In the NMES group, the RH-PAT index and Foot-tcPO2 increased significantly after NMES (P < 0.05 and P < 0.001, respectively). No significant changes were observed in these parameters throughout the session in the control group. In conclusion, a single session of NMES with muscle contraction enhanced vascular endothelial function, leading to improvement in peripheral blood circulation without inducing excessive cardiovascular and autonomic responses in patients with AMI (UMIN000014196).


Asunto(s)
Terapia por Estimulación Eléctrica , Endotelio Vascular/fisiopatología , Pierna/irrigación sanguínea , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/rehabilitación , Flujo Sanguíneo Regional/fisiología , Anciano , Hemodinámica/fisiología , Humanos , Masculino , Manometría , Persona de Mediana Edad , Contracción Muscular , Músculo Esquelético , Estudios Prospectivos
6.
J Electrocardiol ; 49(1): 99-101, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26744169

RESUMEN

Neuromuscular electrical stimulation (NMES) is one of the few exercise modes that have been confirmed to be effective for advanced heart failure patients. Previous clinical trials that verified the effects of NMES excluded patients with implantable cardioverter defibrillators (ICDs). We investigated whether NMES to leg muscles could be applied in heart failure patients implanted with ICDs. As a result, we found that NMES could be conducted without any instances of electromagnetic interference. NMES to leg muscles could be applied safely to ICD patients if the aforementioned common stimulation methods were used with sufficient monitoring during NMES.


Asunto(s)
Artefactos , Terapia por Estimulación Eléctrica , Electrocardiografía , Estimulación Eléctrica Transcutánea del Nervio , Contraindicaciones , Falla de Equipo , Análisis de Falla de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
Neurosci Lett ; 490(3): 185-90, 2011 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-21194556

RESUMEN

Leptin is an appetite-controlling peptide secreted from adipose tissue. Previously, we showed that the gene expression of acetoacetyl-CoA synthetase (AACS), the ketone body-utilizing enzyme for lipid synthesis, was suppressed by leptin deficiency-induced obesity in white adipose tissue. In this study, to clarify the effects of leptin on ketone body utilization in the central nervous system, we examined the effects of leptin signaling on AACS expression. In situ hybridization analysis of ob/ob and db/db mice revealed that AACS mRNA level was reduced by leptin deficiency in the arcuate nucleus (Arc) and ventromedial hypothalamic nucleus (VMH) in hypothalamus but not in other brain regions. Moreover, AACS mRNA level was increased by leptin treatment both in primary cultured neural cells and in N41 neural-like cells. In N41 cells, AACS level was decreased by AMPK inducer but increased by AMPK inhibitor. These results suggest that the up-regulation of AACS expression by leptin is due to the suppression of AMPK activity via neural leptin signaling and that the deficiency of this regulation may be responsible for neurological disorders in central appetite control.


Asunto(s)
Hipotálamo/citología , Cuerpos Cetónicos/metabolismo , Leptina/farmacología , Neuronas/efectos de los fármacos , Regulación hacia Arriba/efectos de los fármacos , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacología , Animales , Células Cultivadas , Coenzima A Ligasas/genética , Coenzima A Ligasas/metabolismo , Coenzima A Transferasas/genética , Coenzima A Transferasas/metabolismo , Inhibidores Enzimáticos/farmacología , Hipoglucemiantes/farmacología , Masculino , Ratones , Ratones Obesos , Neuronas/metabolismo , Pirazoles/farmacología , Pirimidinas/farmacología , ARN Mensajero/metabolismo , Receptores de Leptina/genética , Receptores de Leptina/metabolismo , Ribonucleótidos/farmacología , Factores de Tiempo
8.
J Bone Miner Metab ; 26(2): 143-51, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18301970

RESUMEN

We performed this study to clarify whether celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, prevents trabecular bone mass reduction by suppressing arthritis-related increase of bone resorption, and to discriminate differences in actions on bone among celecoxib, SC-58560 (a selective COX-1 inhibitor), and indomethacin. Eight-week-old DBA/1J male mice were divided into six groups as follows. Control untreated (Normal) and collagen-induced arthritic (CIA) mice were compared with four treatment groups: celecoxib was orally administered to CIA mice at doses of 0 (Vehicle), 16 (COX2L), and 75 (COX2H) mg/kg, in addition to two groups of mice treated with SC-58560 (COX1) or indomethacin (IND). Histomorphometry showed a significant decrease in tibial trabecular bone volume in arthritic mice, which was corrected by COX2H. The increased osteoclast surface and number in the Vehicle group were suppressed by COX2L, COX2H, and IND. The decreased bone formation rate in Vehicle was elevated by COX2H without statistical significance. A high ratio of mRNA expression of receptor activator of NF-kappaB ligand (RANKL)/osteoprotegerin (OPG) in Vehicle synovial tissue was suppressed by COX2L and COX2H. The increased expression of interleukin (IL)-6 mRNA in Vehicle was suppressed by COX2L, COX2H, and IND, although no difference in this expression was observed in bone marrow cells among all groups. In conclusion, in CIA mice, celecoxib suppresses arthritis-related increase in bone resorption at low and high doses and prevents trabecular bone mass reduction at high doses in association with suppression of osteoclast development in bone marrow through inhibition of RANKL/OPG ratio and IL-6 mRNA expression in inflammatory synovial tissue.


Asunto(s)
Artritis Experimental/fisiopatología , Huesos/fisiopatología , Inhibidores de la Ciclooxigenasa 2/farmacología , Interleucina-6/genética , Osteoprotegerina/genética , Ligando RANK/genética , Membrana Sinovial/metabolismo , Aminoácidos/orina , Animales , Biomarcadores/metabolismo , Peso Corporal/efectos de los fármacos , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Huesos/efectos de los fármacos , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Interleucina-6/metabolismo , Masculino , Ratones , Tamaño de los Órganos/efectos de los fármacos , Osteocalcina/sangre , Osteoprotegerina/metabolismo , Ligando RANK/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Tibia/efectos de los fármacos , Tibia/fisiopatología
9.
Early Hum Dev ; 83(5): 285-91, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-16891065

RESUMEN

BACKGROUND: Currently, there are no nutritional indices to predict cognitive function in extremely low-birth-weight (ELBW) infants. OBJECTIVE: To assess the neonatal blood urea nitrogen (BUN) values in ELBW infants according to their cognitive function at the corrected age of 36 months. METHODS: This was a retrospective study that assessed the neonatal factors affecting the developmental outcome in two groups "developmental quotient (DQ)> or =80" and "DQ<80", the groups were divided based on the DQ at the corrected age of 36 months. Between 1996 and 1999, 178 ELBW infants born at <28 weeks of gestation were admitted to our neonatal intensive care unit (NICU), of these, 32 died. Of the surviving 146 infants, 37 infants without any exclusion criteria (that would affect the cognitive function and BUN) except the nutritional factor, were assessed. Area under the curve (AUC) of corrected BUN (CBUN: BUN x 0.5/serum creatinine) from 28 to 84 days of life was used as an index of protein intake. RESULTS: No significant differences were observed between the two groups with regard to the gestational age, birth weight, Z score of birth weight, and sex. However, compared to 15 infants with DQ<80, 22 infants with DQ> or =80 had significantly shorter duration of artificial ventilation and O(2) supplementation, a higher Apgar score at 5 min, and a higher AUC of CBUN. On multiple regression analysis, DQ> or =80 was observed to be significantly correlated with the AUC of CBUN (Odd's ratio 1.03, 95% confidence interval: 1.002-1.06). CONCLUSION: The CBUN level would provide an estimate of adequate protein intake and the subsequent development of an ELBW infant.


Asunto(s)
Nitrógeno de la Urea Sanguínea , Desarrollo Infantil/fisiología , Recien Nacido con Peso al Nacer Extremadamente Bajo/crecimiento & desarrollo , Peso al Nacer , Preescolar , Cognición/fisiología , Suplementos Dietéticos , Femenino , Edad Gestacional , Humanos , Recien Nacido con Peso al Nacer Extremadamente Bajo/metabolismo , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Masculino , Leche Humana/química , Estudios Retrospectivos
10.
J Bone Miner Res ; 19(11): 1813-20, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15476581

RESUMEN

UNLABELLED: We analyzed the effect of unloading by tail suspension on the anabolic action of intermittent PTH in the tibia of growing mice. Unloading alleviated the PTH-induced increase of bone formation and accelerated bone resorption, consequently reducing bone mass. Reduction of the PTH-induced anabolic actions on bone was associated with unloading, which was apparently related to suppression of c-fos mRNA expression in bone marrow. INTRODUCTION: The effects of intermittent parathyroid hormone (PTH) administration on unloading bone have not been well elucidated at the cellular and molecular levels. We tested the effects of PTH on unloaded tibias of tail-suspended mice. MATERIALS AND METHODS: Eighty male C57BL/6J mice, 8 weeks of age, were divided into four groups with loading or unloading and administration of PTH (40 microg/kg body weight) or vehicle five times per week. Mice were killed at 8 or 15 days, and both tibias were obtained. Bone histomorphometry of the trabecular bone in the proximal tibia, development of osteogenic cells, and mRNA expression of osteogenic molecules in bone marrow cells were assessed. RESULTS AND CONCLUSIONS: At 15 days of unloading, bone volume decreased in PTH-treated mice. The increase in the bone formation rate by PTH was depressed, and the osteoclast surface was thoroughly increased. The increase in alkaline phosphatase-positive colony-forming units-fibroblastic (CFU-f) colonies induced by PTH was maintained and that of TRACP+ multinucleated cells enhanced. The PTH-induced increase in c-fos mRNA was depressed, but the increases in Osterix and RANKL mRNA were maintained. Unloading promoted the PTH-associated osteoclastogenesis and seemed to delay the progression of osteogenic differentiation in association with reduction of the PTH-dependent increase of c-fos mRNA in bone marrow cells.


Asunto(s)
Células de la Médula Ósea/citología , Hormona Paratiroidea/farmacología , Fragmentos de Péptidos/farmacología , Proteínas Proto-Oncogénicas c-fos/metabolismo , ARN Mensajero/metabolismo , Tibia/efectos de los fármacos , Fosfatasa Alcalina/metabolismo , Animales , Peso Corporal , Células de la Médula Ósea/metabolismo , Huesos , Proteínas Portadoras/metabolismo , Diferenciación Celular , Cartilla de ADN/química , ADN Complementario/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Ligando RANK , ARN/metabolismo , Receptor Activador del Factor Nuclear kappa-B , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción Sp7 , Células Madre , Tibia/metabolismo , Factores de Tiempo , Factores de Transcripción/metabolismo
11.
J Bone Miner Metab ; 22(5): 404-14, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15316861

RESUMEN

The relationship between bone turnover and bone tissue and material properties was examined in ovariectomized (OVX) rats treated with risedronate in combination with or without vitamin K2. Seventy female rats, 18 weeks of age, were assigned to 7 groups (n=10): sham-operated + vehicle control; OVX + vehicle control; OVX + risedronate 0.1, 0.5, or 2.5 mg/kg/day po; OVX + vitamin K2 approximately 30 mg/kg/day po; OVX + vitamin K2 (approximately 30 mg/kg/day) and risedronate (0.5 mg/kg/day). Treatments were given daily for 9 months. To assess bone turnover, we measured serum osteocalcin and urinary deoxypyridinoline at 0, 3, and 9 months. To assess vertebral and femoral tissue and material properties, bone mass, bone mineral density (BMD by DXA), trabecular bone structure (vertebra: 3D-microCT), cortical bone structure (femur: histomorphometry), biomechanical properties, and mineral properties (mineral-to-matrix and carbonate-to-phosphate ratios by Fourier transform infrared microspectroscopy) were measured ex vivo at 9 months. Ovariectomy increased bone turnover and induced significant loss of bone mass/density, structure, mineral properties (mineral-to-matrix ratio), and strength. Risedronate produced dose-dependent inhibition of the ovariectomy-induced increase in turnover and loss of bone mass/density, structure, mineral-to-matrix ratio, and strength, with a lowest effective dose of 0.1-0.5 mg/kg/day. High-dose risedronate (2.5 mg/kg/day) did not induce increases in any parameter above that of sham control. Vitamin K2 had no effects. In the OVX groups, urinary deoxypyridinoline at 3 and 9 months correlated significantly with vertebral BMD, trabecular bone volume, ultimate load, stiffness, and mineral-to-matrix ratio, and with femoral BMD, cortical area, and ultimate load. These results support the concept that changes in bone tissue and material properties can result directly from changes in bone turnover. Different effects among different drugs on material properties, including mineral-to-matrix ratio, may reflect differences in the relative rate and magnitude of osteoclastic bone resorption and osteoblastic primary bone mineralization.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Matriz Ósea/efectos de los fármacos , Ácido Etidrónico/análogos & derivados , Ácido Etidrónico/farmacología , Vértebras Lumbares/efectos de los fármacos , Vitamina K 2/farmacología , Absorciometría de Fotón , Aminoácidos/orina , Animales , Fenómenos Biomecánicos , Peso Corporal/efectos de los fármacos , Matriz Ósea/metabolismo , Femenino , Fémur/efectos de los fármacos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/metabolismo , Osteocalcina/sangre , Osteocalcina/efectos de los fármacos , Ovariectomía , Ratas , Ratas Sprague-Dawley , Ácido Risedrónico , Espectroscopía Infrarroja por Transformada de Fourier , Tomografía Computarizada por Rayos X
12.
Bone ; 34(6): 940-8, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15193540

RESUMEN

Prostaglandin E(2) (PGE(2)) is essential for fracture healing. Systemic administration of EP4 ligands such as PGE(2) and other synthetic EP4 agonists appears to transduce anabolic signals by binding to receptor EP4. Therefore, the present study was designed to test whether administration of EP4 agonist accelerates the healing of drill-hole injury in the femoral diaphysis. After surgery, a total of 128 Wistar rats, at the age of 12 weeks, were assigned to basal control (n = 8), and three groups with respective doses of 0 (vehicle control), 10 (low-dose), and 30 (high-dose) microg/kg body weight of the agent were subcutaneously injected twice a day. Femoral specimens were obtained at 0, 5, 7, 14, 21, and 28 days. In EP4 agonist-treated groups, the total bone volume of the regenerating bone in the defect did not significantly differ, but the regenerated cortical bone volume measured by histomorphometry and cortical bone mineral content (Ct. BMC) by pQCT dose-dependently increased at 14 and 21 days compared to the control. In the high-dose group, the value of osteoclast surface significantly increased compared with that in the control at 14 days. Expression levels of osteocalcin and TRAP mRNAs in the injured tissue increased at 14 days. Expression levels of EP4, BMP-2, and RANKL mRNAs increased at 7 days in the high-dose group. The bone mineral values of the lumbar bone at 28 days, measured by DXA, did not differ in the three groups. These data indicated that systemic administration of EP4 agonist ONO-4819.CD accelerated cortical bone healing after drill-hole injury by upregulating the local turnover of the regenerating bone.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Fémur/efectos de los fármacos , Fémur/lesiones , Heptanoatos/farmacología , Receptores de Prostaglandina E/agonistas , Regulación hacia Arriba/efectos de los fármacos , Animales , Regeneración Ósea/fisiología , Remodelación Ósea/efectos de los fármacos , Remodelación Ósea/fisiología , Fémur/fisiología , Masculino , Ratas , Ratas Wistar , Receptores de Prostaglandina E/fisiología , Subtipo EP4 de Receptores de Prostaglandina E , Regulación hacia Arriba/fisiología
13.
J Biol Chem ; 279(17): 17205-16, 2004 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-14963045

RESUMEN

The CagA protein of Helicobacter pylori, which is injected from the bacteria into bacteria-attached gastric epithelial cells, is associated with gastric carcinoma. CagA is tyrosine-phosphorylated by Src family kinases, binds the SH2 domain-containing SHP-2 phosphatase in a tyrosine phosphorylation-dependent manner, and deregulates its enzymatic activity. We established AGS human gastric epithelial cells that inducibly express wild-type or a phosphorylation-resistant CagA, in which tyrosine residues constituting the EPIYA motifs were substituted with alanines. Upon induction, wild-type CagA, but not the mutant CagA, elicited strong elongation of cell shape, termed the "hummingbird" phenotype. Time-lapse video microscopic analysis revealed that the CagA-expressing cells exhibited a marked increase in cell motility with successive rounds of elongation-contraction processes. Inhibition of CagA phosphorylation by an Src kinase inhibitor, PP2, or knockdown of SHP-2 expression by small interference RNA (siRNA) abolished the CagA-mediated hummingbird phenotype. The morphogenetic activity of CagA also required Erk MAPK but was independent of Ras or Grb2. In AGS cells, CagA prolonged duration of Erk activation in response to serum stimulation. Conversely, inhibition of SHP-2 expression by siRNA abolished the sustained Erk activation. Thus, SHP-2 acts as a positive regulator of Erk activity in AGS cells. These results indicate that SHP-2 is involved in the Ras-independent modification of Erk signals that is necessary for the morphogenetic activity of CagA. Our work therefore suggests a key role of SHP-2 in the pathological activity of H. pylori virulence factor CagA.


Asunto(s)
Antígenos Bacterianos/fisiología , Proteínas Bacterianas/fisiología , Helicobacter pylori/metabolismo , Proteínas Tirosina Fosfatasas/metabolismo , Animales , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Células COS , Línea Celular , ADN Complementario/metabolismo , Activación Enzimática , Vectores Genéticos , Humanos , Immunoblotting , Péptidos y Proteínas de Señalización Intracelular , Microscopía por Video , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fenotipo , Fosforilación , Pruebas de Precipitina , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Proteínas Tirosina Fosfatasas con Dominio SH2 , Estómago/microbiología , Estómago/patología , Factores de Tiempo , Transfección , Tirosina/química , Tirosina/metabolismo , Proteínas ras/metabolismo
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