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Aim: To review the indications for rectal mucosal/submucosal biopsy (RMSBx) used for diagnosing Hirschsprung's disease (HD) in pediatric patients. Methods: The medical records of all children between 1 and 15 years old assessed for chronic constipation between 2012 and 2022 were reviewed. Until the end of 2018, enema usage (E+) was a major indication for RMSBx. In 2019, laxative use for 3 months irrespective of enema use was added as an indication (L+). To determine the relevance of enema usage, L+ was subdivided by enema usage into (L+E+) and (L+E-) groups. The effect of changing the indications for RMSBx on the incidence of HD was investigated. Results: Of 562 eligible subjects, E+ = 410, L+ = 152; demographics are similar. RMSBx rate in E+ (E+RMSBx) was 36/410 (8.8%) and in L+ (L+RMSBx) was 42/152 (27.6%;) (P < .05). For L+RMSBx, 15/42 were L+E+ and 27/42 were L+E-. HD incidence in E+RMSBx was 8/36 (22.2%; E+HD) and in L+RMSBx was 13/42 (31.0%; L+HD) (p = ns). In L+RMSBx, HD incidence in L+E+ was 5/15 (33.3%; L+E+HD) and in L+E- was 8/27 (29.6%; L+E-HD) (P = ns). Differences in daily bowel motion frequency 6 months postoperatively were not statistically significant; E+HD (1.75/d) versus L+HD (2.03/d) and L+E+HD (1.60/day) versus L+E-HD (2.31/day). Unassisted voluntary defecation was confirmed 12 months postoperatively in 7/8 (87.5%) E+HD, 11/13 (84.6%) L+HD, 4/5 (80.0%) L+E+HD, and 7/8 (87.5%) L-E-HD; differences were not significant. Laxatives were still required in 2/8 (25.0%) E+HD, 3/13 (23.1%) L+HD, in 1/5 (20.0%) in L+E+HD, and 2/8 (25.0%) L+E-HD; differences were not significant. Conclusion: Incidence of HD was higher in L+HD, but not significantly different suggesting that indications for RMSBx have potential to influence incidence of HD and hint that the incidence of HD could actually be higher. Further assessment of additional indications is warranted to diagnose HD with greater accuracy.
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PURPOSE: Mid-shaft/proximal (msp) and penoscrotal/scrotal/perineal (pssp) hypospadias treated by urethroplasty (UP) terminating at the corona (UPC) or UP terminating at the tip of the glans (UPG) were compared. METHODS: UP performed at a single institute (n = 234) between 2003 and 2020 were grouped as: msp-UPC (n = 23), msp-UPG (n = 75), pssp-UPC (n = 81), and pssp-UPG (n = 55) to compare data obtained from medical records for post-UP complications (PUC; urethral stenosis, urethrocutaneous fistula, diverticulum formation, and bleeding; n = 234), post-UP uroflowmetry (PUF; average flow rate (Qave), maximum flow rate (Qmax), voiding time (VT), voided volume (VV) and urine flow curves) in 57 UP patients [msp-UPC (n = 5), msp-UPG (n = 12), pssp-UPC (n = 32), pssp-UPG (n = 8)] and 9 controls, and post-UPC esthetics (EST; n = 104). P < 0.05 was considered significant. RESULTS: Mean ages at UP (years) were: msp-UPC (3.1 ± 3.0), msp-UPG (3.3 ± 1.4), pssp-UPC (4.6 ± 2.4), and pssp-UPG (3.4 ± 1.4); p < 0.0001 by ANOVA test. Overall, there were significantly more PUC in pssp-UPG compared with pssp-UPC except for bleeding. Ages at PUF assessment were similar. Mean Qave (mL/s) for pssp-UPG (4.0 ± 1.0) was significantly less than pssp-UPC (5.9 ± 2.5; p < 0.05) and both were significantly less than controls (6.9 ± 1.8; p < 0.05, p < 0.01, respectively). Mean Qmax (mL/s) for pssp-UPC (11.4 ± 4.8) was significantly better than pssp-UPG (7.8 ± 2.3; p < 0.05) and for controls (14.9 ± 4.4) was significantly better than pssp-UPG (7.8 ± 2.3; p < 0.01). All VT (seconds) were similar to controls; all urine flow curves were normal. For EST in UPC (n = 104), 3 cases requested meatal advancement. CONCLUSIONS: UPC may be a valid option for treating pssp hypospadias because of significant differences in PUC/PUF and minimal EST issues compared with UPG. LEVEL OF EVIDENCE: Prognosis Study Level-â ¡.
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Hipospadias , Procedimientos de Cirugía Plástica , Masculino , Humanos , Lactante , Hipospadias/cirugía , Hipospadias/complicaciones , Resultado del Tratamiento , Procedimientos Quirúrgicos Urológicos Masculinos , Uretra/cirugía , EstéticaRESUMEN
While human milk is considered the optimal source of nutrition for infants for the first six and twelve months of age, with continued benefit of breastfeeding with complementary foods, a safe alternative, nutritionally adequate to support infant growth and development, is necessary. In the United States, the Food and Drug Administration (FDA) establishes the requirements necessary to demonstrate the safety of infant formula within the framework of the Federal Food, Drug, and Cosmetic Act. FDA's Center for Food Safety and Applied Nutrition/Office of Food Additive Safety evaluates the safety and lawfulness of individual ingredients used in infant formula, whereas the Office of Nutrition and Food Labeling oversees the safety of infant formula. Most infant formula ingredients are either from sources with history of safe consumption by infants or are like components in human milk. Information demonstrating the regulatory status of all ingredients is required in submissions for new infant formulas, and ingredient manufacturers often use the Generally Recognized as Safe (GRAS) Notification program to establish ingredient regulatory status. We provide an overview of ingredients used in infant formula evaluated through the GRAS Notification program to highlight trends and discuss the data and information used to reach these GRAS conclusions.
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Aditivos Alimentarios , Fórmulas Infantiles , Lactante , Humanos , Estados Unidos , Inocuidad de los Alimentos , Etiquetado de Alimentos , Estado Nutricional , United States Food and Drug AdministrationRESUMEN
Nitric oxide and reactive oxygen species regulate bone remodeling, which occurs via bone formation and resorption by osteoblasts and osteoclasts, respectively. Recently, we found that 8-nitro-cGMP, a second messenger of nitric oxide and reactive oxygen species, promotes osteoclastogenesis. Here, we investigated the formation and function of 8-nitro-cGMP in osteoblasts. Mouse calvarial osteoblasts were found to produce 8-nitro-cGMP, which was augmented by tumor necrosis factor-α (10â ng/ml) and interleukin-1ß (1â ng/ml). These cytokines suppressed osteoblastic differentiation in a NO synthase activity-dependent manner. Exogenous 8-nitro-cGMP (30â µmol/L) suppressed expression of osteoblastic phenotypes, including mineralization, in clear contrast to the enhancement of mineralization by osteoblasts induced by 8-bromo-cGMP, a cell membrane-permeable analog of cGMP. It is known that reactive sulfur species denitrates and degrades 8-nitro-cGMP. Mitochondrial cysteinyl-tRNA synthetase plays a crucial role in the endogenous production of RSS. The expression of osteoblastic phenotypes was suppressed by not only exogenous 8-nitro-cGMP but also by silencing of the Cars2 gene, indicating a role of endogenous 8-nitro-cGMP in suppressing the expression of osteoblastic phenotypes. These results suggest that 8-nitro-cGMP is a negative regulator of osteoblastic differentiation.
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BACKGROUND: While thrombosis is a well-known complication of coronavirus disease 2019 (COVID-19) infection, reports on intestinal necrosis due to intestinal ischemia caused by thrombosis are extremely rare. We herein report a case of intestinal necrosis due to multiple thrombosis in a COVID-19 patient. CASE PRESENTATION: The patient was a 64-year-old man. He was admitted to hospital after being diagnosed with COVID-19, the severity was classified as moderate II. Nasal High Flow™ management was conducted along with treatment with tocilizumab, remdesivir, and dexamethasone. Heparin was also administered due to high D-dimer values. As abdominal pain appeared from the 6th day of hospitalization, contrast-enhanced CT was performed, which confirmed multiple thrombosis in the aorta. However, no obvious intestinal ischemia was found. On the 10th day of hospitalization, the patient's abdominal pain was exacerbated. Upon re-evaluation by CT, he was diagnosed with perforative peritonitis due to ileal ischemic necrosis and emergency surgery was performed. Intraoperative examination revealed perforation due to necrosis at multiple sites in the ileum; thus, partial ileectomy was carried out. Pathological findings also revealed discontinuous multiple intestinal necrosis due to the frequent occurrence of thrombosis. Following surgery, the patient recuperated and was discharged after ventilator management and multimodal therapy at the ICU. CONCLUSIONS: Thrombosis due to COVID-19 complications is rare in the intestinal tract, but also occur. Its initial symptoms might not be captured by CT images, therefore caution is required.
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Surface pressure (π)-area (A) isotherms were studied to analyze the interactions between a hydrophilic ionic liquid (IL) (ethyl(2-hydroxyethyl)dimethylammonium methanesulfonate) and a pure dipalmitoylphosphatidylcholine (DPPC) film or a DPPC-cholesterol mixed film. When the hydrophilic IL was added to an underlayer solution, the isotherm shifted toward higher areas. Intriguingly, when the hydrophilic IL was added, the packing of the film materials became loose and the elastic modulus decreased, resulting in increased flexibility. This phenomenon was most evident under a cholesterol mole fraction of 0.2. This composition resembles that of cell membranes, which typically comprise phospholipids and cholesterol, suggesting that this hydrophilic IL may be able to interact significantly with biological membranes.
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1,2-Dipalmitoilfosfatidilcolina/química , Colesterol/química , Interacciones Hidrofóbicas e Hidrofílicas , Líquidos Iónicos/química , Fosfolípidos/química , Membrana Celular/química , Polarización de Fluorescencia , Docilidad , Presión , Soluciones , Propiedades de SuperficieRESUMEN
In this study, we synthesize hydrophilic amine-based protic ionic liquids (PILs) with hydroxy groups in a cation and different anions. Subsequently, we evaluate the kinetic friction coefficients of iron oxide in aqueous solutions of the PILs under different sliding conditions. Ditriethanolamine malate, triethanolamine lactate, triethanolamine methoxyacetate, and triethanolamine acetate are used as PIL samples in this study. Among them, ditriethanolamine malate exhibits the lowest kinetic friction coefficient. As the number of sliding cycles increases, the excellent lubrication capability remains. Subsequently, we characterize the adsorption of the PILs on an iron oxide surface to investigate the lubrication behavior on the basis of quartz crystal microbalance with dissipation monitoring and force curve data. We expect hydrophilic PILs to be excellent water-soluble lubricants and additives for use in metal surface treatments.
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Aminas/química , Aniones/química , Interacciones Hidrofóbicas e Hidrofílicas , Líquidos Iónicos/síntesis química , Lubricantes/síntesis química , Lubrificación , Tecnicas de Microbalanza del Cristal de Cuarzo , Adsorción , Compuestos Férricos/química , Líquidos Iónicos/química , Solubilidad , Soluciones , AguaRESUMEN
We synthesized hydrophilic amine-based protic ionic liquids (PILs) with hydroxy groups in their cations and anions, and characterized their adsorption at a solid (iron-based substrate) / aqueous solution interface. The IL samples employed in this study were triethanolamine lactate, diethanolamine lactate, and monoethanolamine lactate. Quartz crystal microbalance with dissipation monitoring (QCM-D) measurements revealed that the adsorption mass of the hydrophilic PILs was larger than that of the comparative materials, including a non-IL sample (1,2,6-hexanetriol) and an OH-free sample in the cations (triethylamine lactate). Additionally, an increase in the number of hydroxy groups in the cations resulted in an increased adsorption mass. Force curve measurements by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements proved the high adsorption density of the hydrophilic PILs on the iron-based substrate. A decreased kinetic friction coefficient was also observed in the hydrophilic PIL systems. Moreover, hydrophilic PILs are expected to have potential applications as water-soluble lubricants and additives for metal surface treatments.
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Aminas/química , Adsorción , Aniones , Cationes , Etanolamina/química , Etanolaminas/química , Interacciones Hidrofóbicas e Hidrofílicas , Hidroxilación , Lubricantes , Solubilidad , Soluciones , AguaRESUMEN
Neutrophils are one of the most abundant leukocytes in the sites of lesion of inflammatory diseases such as periodontitis and rheumatoid arthritis. These diseases are accompanied by bone loss, which worsens the quality of life of the patients. However, the role of neutrophils in the inflammatory bone loss has not been fully investigated. In the present study, we found that human neutrophils enhanced osteoclast differentiation from mouse bone marrow cells co-cultured with mouse osteoblasts in the presence of active vitamin D3. The enhanced osteoclast differentiation was significantly suppressed by elastatinal, a synthetic inhibitor of neutrophil elastase. Also, we found that human neutrophils degraded human recombinant osteoprotegerin (OPG), a decoy receptor for nuclear factor κB (RANK) ligand (RANKL), the essential osteoclast differentiation-inducing factor, expressed by osteoblasts. Degradation of OPG by neutrophils was suppressed by human α1-protease inhibitor, the major endogenous inhibitor of neutrophil elastase. Recombinant human neutrophil elastase degraded human OPG in its death domain-like region. These results indicated that the degradation of OPG by elastase contributed at least in part to the enhanced osteoclast differentiation by neutrophils. There is a possibility that neutrophils play an important role in inflammatory bone loss.
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Osteoclastos , Osteoprotegerina , Animales , Proteínas Portadoras , Diferenciación Celular , Glicoproteínas/metabolismo , Humanos , Glicoproteínas de Membrana , Ratones , Neutrófilos/metabolismo , Osteoclastos/metabolismo , Elastasa Pancreática , Calidad de Vida , Ligando RANK , Receptor Activador del Factor Nuclear kappa-B , Receptores Citoplasmáticos y NuclearesRESUMEN
Osteocytes regulate bone remodeling, especially in response to mechanical loading and unloading of bone, with nitric oxide reported to play an important role in that process. In the present study, we found that 8-nitroguanosine 3',5'-cyclic monophosphate (8-nitro-cGMP), a second messenger of nitric oxide in various types of cells, was produced by osteocytes in bone tissue as well as cultured osteocytic Ocy454 cells. The amount of 8-nitro-cGMP in Ocy454 cells increased during incubation with parathyroid hormone or prostaglandin E2, both of which are known to upregulate receptor activator of nuclear factor-κB ligand (RANKL) mRNA expression in osteocytes. On the other hand, exogenous 8-nitro-cGMP did not have effects on either the presence or absence of these bioactive substances. Furthermore, neither an inhibitor of nitric oxide synthase nor 8-bromo-cGMP, a cell-permeable analog of cGMP, showed remarkable effects on mRNA expression of sclerostin or RANKL. These results indicate that neither nitric oxide nor its downstream compounds, including 8-nitro-cGMP, alone are sufficient for induction of functional changes in osteocytes.
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GMP Cíclico/análogos & derivados , Dinoprostona/farmacología , Osteocitos/metabolismo , Hormona Paratiroidea/farmacología , Regulación hacia Arriba , Proteínas Adaptadoras Transductoras de Señales , Animales , Línea Celular , GMP Cíclico/biosíntesis , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Fémur/citología , Glicoproteínas/genética , Glicoproteínas/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Masculino , Ratones Endogámicos C57BL , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Ligando RANK/genética , Ligando RANK/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
In endochondral ossification, growth of bones occurs at their growth plate cartilage. While it is known that nitric oxide (NO) synthases are required for proliferation of chondrocytes in growth plate cartilage and growth of bones, the precise mechanism by which NO facilitates these process has not been clarified yet. C-type natriuretic peptide (CNP) also positively regulate elongation of bones through expansion of the growth plate cartilage. Both NO and CNP are known to use cGMP as the second messenger. Recently, 8-nitro-cGMP was identified as a signaling molecule produced in the presence of NO in various types of cells. Here, we found that 8-nitro-cGMP is produced in proliferating chondrocytes in the growth plates, which was enhanced by CNP, in bones cultured ex vivo. In addition, 8-nitro-cGMP promoted bone growth with expansion of the proliferating zone as well as increase in the number of proliferating cells in the growth plates. 8-Nitro-cGMP also promoted the proliferation of chondrocytes in vitro. On the other hand, 8-bromo-cGMP enhanced the growth of bones with expansion of hypertrophic zone of the growth plates without affecting either the width of proliferating zone or proliferation of chondrocytes. These results indicate that 8-nitro-cGMP formed in growth plate cartilage accelerates chondrocyte proliferation and bone growth as a downstream molecule of NO.
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Desarrollo Óseo/efectos de los fármacos , Cartílago/efectos de los fármacos , Condrocitos/efectos de los fármacos , GMP Cíclico/análogos & derivados , Placa de Crecimiento/efectos de los fármacos , Tibia/efectos de los fármacos , Animales , Cartílago/citología , Cartílago/crecimiento & desarrollo , Cartílago/metabolismo , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Condrocitos/citología , Condrocitos/metabolismo , GMP Cíclico/farmacología , Feto , Placa de Crecimiento/citología , Placa de Crecimiento/crecimiento & desarrollo , Placa de Crecimiento/metabolismo , Ratones , Ratones Endogámicos ICR , Péptido Natriurético Tipo-C/farmacología , Óxido Nítrico/metabolismo , Cultivo Primario de Células , Tibia/citología , Tibia/crecimiento & desarrollo , Tibia/metabolismo , Técnicas de Cultivo de TejidosRESUMEN
Dietary exposure assessment using food-consumption data and ingredient-use level is essential for assessing the safety of food ingredients. Dietary exposure estimates are compared with safe intake levels, such as the acceptable daily intake (ADI). The ADI is estimated by applying a safety factor to an experimentally determined no-observed-adverse-effect level of a test substance. Two food ingredients classified as emulsifiers, carboxymethylcellulose (CMC) and polysorbate 80 (P80), received attention recently due to their putative adverse effects on gut microbiota. Because no published dietary exposure estimates for commonly used emulsifiers exist for the US population, the current investigation focused on the estimation of dietary exposure to seven emulsifiers: CMC, P80, lecithin, mono- and diglycerides (MDGs), stearoyl lactylates, sucrose esters, and polyglycerol polyricinoleate. Using maximum-use levels obtained from publicly available sources, dietary exposures to these emulsifiers were estimated for the US population (aged 2 years and older) for two time periods (1999-2002 and 2003-10) using 1- and 2-day food-consumption data from the National Health and Nutrition Examination Survey, and 10-14-day food-consumption data from NPD Group, Inc.'s National Eating Trends - Nutrient Intake Database. Our analyses indicated that among the emulsifiers assessed, lecithin and MDGs have the highest mean exposures at about 60 and about 80 mg kg-1 bw day-1, respectively, whereas the exposure to CMC is half to one-third that of lecithin or MDGs; and the exposure to P80 is approximately half that of CMC. The review of available safety information such as ADIs established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), in light of our updated dietary exposure estimates for these seven emulsifiers, did not raise safety concerns at the current specified levels of use. Additionally, by examining two time periods (1999-2002, 2003-10), it was concluded that there is no evidence that exposure levels to emulsifiers have substantially increased.
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Dieta/efectos adversos , Emulsionantes/análisis , Aditivos Alimentarios/análisis , Inocuidad de los Alimentos , Humanos , Encuestas Nutricionales , Medición de Riesgo , Estados UnidosRESUMEN
Osteoarthritis is a degenerative joint disease caused by excessive death of chondrocytes and loss of the extracellular matrix (ECM) in articular cartilage. We previously reported that reactive oxygen species (ROS) generated by the NADPH oxidase (NOX) isoform NOX-2 are involved in chondrocyte death induced by interleukin-1ß (IL-1ß). In this study, we investigate the role of NOX-2 in the production and degradation of ECM by chondrocytes. Although IL-1ß lowered the mRNA expression of type II collagen (Col2a1) and aggrecan (Acan) in mouse chondrocyte-like ATDC5 cells, RNA silencing of Nox2 did not change the mRNA expression of these major components of the ECM of cartilage. Hence, NOX-2 is not involved in the IL-1ß-induced suppression of ECM production. On the other hand, the NOX inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), the ROS scavenger N-acetylcysteine and an antisense oligodeoxynucleotide for Nox2 prevented the loss of proteoglycan induced by IL-1ß in highly differentiated ATDC5 cells. Furthermore, AEBSF did not affect the expression of hyaluronidase-1 and -2, whereas it suppressed hyaluronidase activity in culture medium. IL-1ß-induced intra- and extracellular acidification was also suppressed by AEBSF, as was the antisense oligodeoxynucleotide for Nox2. Since hyaluronidase activity is known to be higher under acidic conditions, NOX-2 probably contributes to ECM loss by the activation of hyaluronidase through acidification.
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Condrocitos/metabolismo , Matriz Extracelular/metabolismo , Interleucina-1beta/farmacología , NADPH Oxidasas/metabolismo , Acetilcisteína/farmacología , Ácidos/metabolismo , Agrecanos/genética , Agrecanos/metabolismo , Células Cultivadas , Condrocitos/efectos de los fármacos , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Medios de Cultivo/farmacología , Inhibidores Enzimáticos/farmacología , Matriz Extracelular/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ácido Hialurónico/metabolismo , Hialuronoglucosaminidasa/metabolismo , Concentración de Iones de Hidrógeno , Proteoglicanos/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Sulfonas/farmacologíaRESUMEN
It is known that diabetes aggravates alveolar bone loss associated with periodontitis. While insulin depletion increases the blood concentration of ketone bodies, i.e., acetoacetate and ß-hydroxybutyrate, their roles in bone metabolism have not been much studied until today. We investigated the effects of acetoacetate and ß-hydroxybutyrate on mineralization of extracellular matrix in cultures of mouse osteoblastic MC3T3-E1 cells and primary mouse osteoblasts in the presence and absence of bone morphogenetic protein-2. Acetoacetate potentiated alkaline phosphatase activity in MC3T3-E1 cells in a concentration-dependent manner, ranging from physiological to pathological concentrations (0.05-5 mmol/L). In contrast, ß-hydroxybutyrate lowered it in the same experimental settings. Mineralization in cultures of these cells was also up-regulated by acetoacetate and down-regulated by ß-hydroxybutyrate. Similar results were obtained in cultures of mouse primary osteoblasts. Neither alkaline phosphatase mRNA nor its protein expression in MC3T3-E1 cells was affected by acetoacetate or ß-hydroxybutyrate, indicating that these ketone bodies control the enzyme activity of alkaline phosphatase in osteoblasts and hence their mineralization bi-directionally. Finally, either gene silencing of monocarboxylate transporter-1, a major transmembrate transporter for ketone bodies, nullified the effects of ketone bodies on alkaline phosphatase activity in MC3T3-E1 cells. Collectively, we found that ketone bodies bidirectionally modulates osteoblast functions, which suggests that ketone bodies are important endogenous factors that regulate bone metabolism in both physiological and pathological situations.
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Ácido 3-Hidroxibutírico/metabolismo , Acetoacetatos/metabolismo , Fosfatasa Alcalina/metabolismo , Calcificación Fisiológica , Cuerpos Cetónicos/metabolismo , Osteoblastos/metabolismo , Animales , Línea Celular , Células Cultivadas , Ratones , Osteoblastos/citologíaRESUMEN
Bropirimine is a synthetic agonist for toll-like receptor 7 (TLR7). In this study, we investigated the effects of bropirimine on differentiation and bone-resorbing activity of osteoclasts in vitro. Bropirimine inhibited osteoclast differentiation of mouse bone marrow-derived macrophages (BMMs) induced by receptor activator of nuclear factor κB ligand (RANKL) in a concentration-dependent manner. Furthermore, it suppressed the mRNA expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), a master transcription factor for osteoclast differentiation, without affecting BMM viability. Bropirimine also inhibited osteoclast differentiation induced in co-cultures of mouse bone marrow cells (BMCs) and mouse osteoblastic UAMS-32 cells in the presence of activated vitamin D3. Bropirimine partially suppressed the expression of RANKL mRNA in UAMS-32 cells induced by activated vitamin D3. Finally, the anti-interferon-ß (IFN-ß) antibody restored RANKL-dependent differentiation of BMMs into osteoclasts suppressed by bropirimine. These results suggest that bropirimine inhibits differentiation of osteoclast precursor cells into osteoclasts via TLR7-mediated production of IFN-ß.
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Citosina/análogos & derivados , Interferón beta/biosíntesis , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Animales , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Línea Celular , Técnicas de Cocultivo , Citosina/farmacología , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , Glicoproteínas de Membrana/agonistas , Ratones , Ratones Endogámicos C57BL , Osteoclastos/inmunología , Ligando RANK/genética , Ligando RANK/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor Toll-Like 7/agonistasRESUMEN
Geminin is a dual-function protein unique to multicellular animals with roles in modulating gene expression and preventing DNA re-replication. Here, we show that geminin is essential at the beginning of mammalian development to prevent DNA re-replication in pluripotent cells, exemplified by embryonic stem cells, as they undergo self-renewal and differentiation. Embryonic stem cells, embryonic fibroblasts, and immortalized fibroblasts were characterized before and after geminin was depleted either by gene ablation or siRNA. Depletion of geminin under conditions that promote either self-renewal or differentiation rapidly induced DNA re-replication, followed by DNA damage, then a DNA damage response, and finally apoptosis. Once differentiation had occurred, geminin was no longer essential for viability, although it continued to contribute to preventing DNA re-replication induced DNA damage. No relationship was detected between expression of geminin and genes associated with either pluripotency or differentiation. Thus, the primary role of geminin at the beginning of mammalian development is to prevent DNA re-replication-dependent apoptosis, a role previously believed essential only in cancer cells. These results suggest that regulation of gene expression by geminin occurs only after pluripotent cells differentiate into cells in which geminin is not essential for viability.
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Apoptosis/fisiología , Diferenciación Celular/fisiología , Replicación del ADN/fisiología , Células Madre Embrionarias/fisiología , Geminina/fisiología , Células Madre Pluripotentes/fisiología , Animales , Supervivencia Celular/fisiología , Células Cultivadas , Geminina/deficiencia , Ratones , Ratones TransgénicosRESUMEN
Geminin is a protein involved in both DNA replication and cell fate acquisition. Although it is essential for mammalian preimplantation development, its role remains unclear. In one study, ablation of the geminin gene (Gmnn) in mouse preimplantation embryos resulted in apoptosis, suggesting that geminin prevents DNA re-replication, whereas in another study it resulted in differentiation of blastomeres into trophoblast giant cells (TGCs), suggesting that geminin regulates trophoblast specification and differentiation. Other studies concluded that trophoblast differentiation into TGCs is regulated by fibroblast growth factor-4 (FGF4), and that geminin is required to maintain endocycles. Here we show that ablation of Gmnn in trophoblast stem cells (TSCs) proliferating in the presence of FGF4 closely mimics the events triggered by FGF4 deprivation: arrest of cell proliferation, formation of giant cells, excessive DNA replication in the absence of DNA damage and apoptosis, and changes in gene expression that include loss of Chk1 with up-regulation of p57 and p21. Moreover, FGF4 deprivation of TSCs reduces geminin to a basal level that is required for maintaining endocycles in TGCs. Thus, geminin acts both like a component of the FGF4 signal transduction pathway that governs trophoblast proliferation and differentiation, and geminin is required to maintain endocycles.
Asunto(s)
Factor 4 de Crecimiento de Fibroblastos/metabolismo , Geminina/metabolismo , Células Gigantes/metabolismo , Trofoblastos/metabolismo , Animales , Apoptosis/genética , Diferenciación Celular , Proliferación Celular , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/biosíntesis , Inhibidor p57 de las Quinasas Dependientes de la Ciclina/biosíntesis , Daño del ADN/genética , Replicación del ADN/genética , Embrión de Mamíferos/embriología , Embrión de Mamíferos/metabolismo , Factor 4 de Crecimiento de Fibroblastos/genética , Geminina/genética , Regulación del Desarrollo de la Expresión Génica , Células Gigantes/citología , Ratones , Ratones Transgénicos , Proteínas Quinasas/deficiencia , Proteínas Quinasas/genética , Interferencia de ARN , ARN Interferente Pequeño , Transducción de Señal , Células Madre/citología , Células Madre/metabolismo , Trofoblastos/citología , Regulación hacia ArribaRESUMEN
It has been suggested that during mouse preimplantation development, the zygotically expressed transcription factor TEAD4 is essential for specification of the trophectoderm lineage required for producing a blastocyst. Here we show that blastocysts can form without TEAD4 but that TEAD4 is required to prevent oxidative stress when blastocoel formation is accompanied by increased oxidative phosphorylation that leads to the production of reactive oxygen species (ROS). Both two-cell and eight-cell Tead4(-/-) embryos developed into blastocysts when cultured under conditions that alleviate oxidative stress, and Tead4(-/-) blastocysts that formed under these conditions expressed trophectoderm-associated genes. Therefore, TEAD4 is not required for specification of the trophectoderm lineage. Once the trophectoderm was specified, Tead4 was not essential for either proliferation or differentiation of trophoblast cells in culture. However, ablation of Tead4 in trophoblast cells resulted in reduced mitochondrial membrane potential. Moreover, Tead4 suppressed ROS in embryos and embryonic fibroblasts. Finally, ectopically expressed TEAD4 protein could localize to the mitochondria as well as to the nucleus, a property not shared by other members of the TEAD family. These results reveal that TEAD4 plays a crucial role in maintaining energy homeostasis during preimplantation development.