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1.
Brachytherapy ; 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39174358

RESUMEN

OBJECTIVE: We utilized the National Cancer Database (NCDB) to evaluate trends and assess outcomes in radiation therapy (RT) boost modality and total dose among medically inoperable endometrial cancer (EC) patients with locoregional disease. METHODS: Patients with International Federation of Gynecology and Obstetrics (FIGO) stage I - IIIC2 inoperable EC treated with RT ± chemotherapy were analyzed. Practice patterns compared external beam RT (EBRT) versus high-dose-rate brachytherapy (BT) boost and total RT dose (palliative: ≤3000 cGy, definitive low dose [DLD]: 4500 - 6249 cGy, definitive high dose [DHD]: ≥6250 cGy) over time. Kaplan-Meier method evaluated overall survival (OS) and Cox proportional hazard modeling assessed variables associated with OS. RESULTS: NCDB included 1755 total cases, of which 1209 received a radiotherapy boost. From 2004 to 2019, boost modality rates differed with increasing utilization of BT consolidation and a decreasing rate of palliation. Predictors of a palliative dose were stage III disease, Black race, N2 disease, and poorly or undifferentiated grade. Multivariable analysis found BT boost was associated with lower mortality compared to EBRT (HR: 0.81, CI: 0.68-0.97; p = 0.019). Mortality rates were higher for palliation versus DHD. Additional factors associated with inferior survival were increasing age, worse Charlson-Deyo score, higher T stage, higher N stage, and moderately, poorly, or undifferentiated grade. CONCLUSIONS: Utilization of BT boost for locoregionally confined, medically inoperable EC has increased since 2004. Brachytherapy consolidation remains an effective RT modality for medically inoperable EC, associated with lower mortality compared to EBRT consolidation.

2.
Brachytherapy ; 23(5): 559-568, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39060143

RESUMEN

PURPOSE: We aim to investigate perioperative and subacute postoperative complications in patients undergoing LDR or HDR monotherapy for prostate cancer. We hypothesize a low rate of complications, and a favorable toxicity profile in patients treated with HDR compared to LDR. MATERIALS AND METHODS: A prospectively collected institutional database was queried for patients treated with HDR or LDR prostate monotherapy between 1998 and 2021. Toxicities were determined per CTCAE. Claims based billing codes were obtained to identify additional events. Events occurring within 4 months of treatment were defined as perioperative or subacute postoperative complications. RESULTS: 759 patients were identified, 446 received LDR with 125I, and 313 received HDR with 192Ir. HDR patients had higher risk features: 75.7% with Gleason score 7+ versus 2.4% of LDR, and 16% with initial PSA 10+ ng/mL versus 2.7% of LDR. Toxicities were mild with the most common being grade 1 GU frequency and nocturia at ∼50%. HDR patients had significantly less grade 2 dysuria (2.6% vs. 9.0%), frequency (4.8% vs. 9.4%), hematuria (1.0% vs. 5.2%), nocturia (3.8% vs. 9.4%), and urinary obstructive symptoms (7.3% vs. 11.2%), all statistically significant. 11 (1.4%) patients had infection requiring antibiotics: 8 (1.8%) from the LDR group and 3 (1%) from the HDR group. Cardiopulmonary events were low at <2% overall, without difference between HDR and LDR. CONCLUSIONS: Overall toxicity rates support the safety of prostate brachytherapy. HDR monotherapy is associated with significantly less perioperative and subacute postoperative GU events when compared to LDR monotherapy. Cardiopulmonary events were equally rare in both groups.


Asunto(s)
Braquiterapia , Complicaciones Posoperatorias , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/radioterapia , Neoplasias de la Próstata/cirugía , Braquiterapia/efectos adversos , Anciano , Complicaciones Posoperatorias/epidemiología , Persona de Mediana Edad , Radioisótopos de Yodo/uso terapéutico , Radioisótopos de Yodo/efectos adversos , Estudios Prospectivos
3.
SLAS Technol ; 23(5): 432-439, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30045649

RESUMEN

A robotic cloud laboratory driven by a state-of-the-art unified laboratory operating system integrates automated hardware, humans, and sensors. This lab of the future system enables researchers to transparently and collaboratively create, optimize, and organize biological experiments to achieve more reproducible results, perform around-the-clock experimentation, and more efficiently navigate the vast parameter space of biology.


Asunto(s)
Automatización de Laboratorios/instrumentación , Disciplinas de las Ciencias Biológicas/instrumentación , Nube Computacional , Humanos , Reproducibilidad de los Resultados
4.
Methods Mol Biol ; 1583: 85-95, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28205169

RESUMEN

Methods to quantify intracellular cholesterol are valuable for the study of its trafficking and storage in normal cells and in lysosomal storage disorders. Traditionally, cholesterol has been tracked using the small molecule, filipin. Filipin can be difficult to visualize and visualization can be cytotoxic as it requires UV illumination. Here we describe a method to measure cholesterol using a fluorescently labeled, mutant form of Perfringolysin O, a soluble protein toxin that binds cholesterol specifically. This approach has been used to measure the impact of NPC1 deficiency on lysosomal cholesterol levels and monitor the rescue of cholesterol export under conditions that reduce the thickness of the lysosomal glycocalyx.


Asunto(s)
Toxinas Bacterianas/química , Colesterol/metabolismo , Citometría de Flujo/métodos , Glicocálix/metabolismo , Proteínas Hemolisinas/química , Enfermedades por Almacenamiento Lisosomal/metabolismo , Lisosomas/metabolismo , Animales , Células CHO , Proteínas Portadoras/metabolismo , Cricetulus , Colorantes Fluorescentes/química , Glicocálix/patología , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular , Enfermedades por Almacenamiento Lisosomal/patología , Lisosomas/patología , Glicoproteínas de Membrana/metabolismo , Proteína Niemann-Pick C1
5.
Trends Endocrinol Metab ; 28(5): 319-339, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28237819

RESUMEN

Having healthy adipose tissue is essential for metabolic fitness. This is clear from the obesity epidemic, which is unveiling a myriad of comorbidities associated with excess adipose tissue including type 2 diabetes, cardiovascular disease, and cancer. Lipodystrophy also causes insulin resistance, emphasizing the importance of having a balanced amount of fat. In cells, the mechanistic target of rapamycin (mTOR) complexes 1 and 2 (mTORC1 and mTORC2, respectively) link nutrient and hormonal signaling with metabolism, and recent studies are shedding new light on their in vivo roles in adipocytes. In this review, we discuss how recent advances in adipose tissue and mTOR biology are converging to reveal new mechanisms that maintain healthy adipose tissue, and discuss ongoing mysteries of mTOR signaling, particularly for the less understood complex mTORC2.


Asunto(s)
Adipocitos/metabolismo , Lipodistrofia/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Animales , Humanos , Resistencia a la Insulina/genética , Resistencia a la Insulina/fisiología , Diana Mecanicista del Complejo 1 de la Rapamicina/fisiología , Diana Mecanicista del Complejo 2 de la Rapamicina/fisiología , Transducción de Señal/genética , Transducción de Señal/fisiología
6.
Cell Rep ; 18(1): 93-106, 2017 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-28052263

RESUMEN

Despite progress in our comprehension of the mechanisms regulating adipose tissue development, the nature of the factors that functionally characterize adipose precursors is still elusive. Defining the early steps regulating adipocyte development is needed for the generation of tools to control adipose tissue size and function. Here, we report the discovery of V-set and transmembrane domain containing 2A (VSTM2A) as a protein expressed and secreted by committed preadipocytes. VSTM2A expression is elevated in the early phases of adipogenesis in vitro and adipose tissue development in vivo. We show that VSTM2A-producing cells associate with the vasculature and express the common surface markers of adipocyte progenitors. Overexpression of VSTM2A induces adipogenesis, whereas its depletion impairs this process. VSTM2A controls preadipocyte determination at least in part by modulating BMP signaling and PPARγ2 activation. We propose a model in which VSTM2A is produced to preserve and amplify the adipogenic capability of adipose precursors.


Asunto(s)
Adipogénesis , Linaje de la Célula , Proteínas de la Membrana/metabolismo , Receptores Inmunológicos/metabolismo , Células 3T3-L1 , Adipocitos/metabolismo , Tejido Adiposo Blanco/irrigación sanguínea , Tejido Adiposo Blanco/citología , Animales , Biomarcadores/metabolismo , Proteínas Morfogenéticas Óseas/metabolismo , Diferenciación Celular , Técnicas de Silenciamiento del Gen , Humanos , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Células 3T3 NIH , Neovascularización Fisiológica , PPAR gamma/metabolismo , Transducción de Señal
7.
Mol Metab ; 5(6): 422-432, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27257602

RESUMEN

OBJECTIVE: Normal adipose tissue growth and function is critical to maintaining metabolic homeostasis and its excess (e.g. obesity) or absence (e.g. lipodystrophy) is associated with severe metabolic disease. The goal of this study was to understand the mechanisms maintaining healthy adipose tissue growth and function. METHODS: Adipose tissue senses and responds to systemic changes in growth factor and nutrient availability; in cells mTORC1 regulates metabolism in response to growth factors and nutrients. Thus, mTORC1 is poised to be a critical intracellular regulator of adipocyte metabolism. Here, we investigate the role of mTORC1 in mature adipocytes by generating and characterizing mice in which the Adiponectin-Cre driver is used to delete floxed alleles of Raptor, which encodes an essential regulatory subunit of mTORC1. RESULTS: Raptor (Adipoq-cre) mice have normal white adipose tissue (WAT) mass for the first few weeks of life, but soon thereafter develop lipodystrophy associated with hepatomegaly, hepatic steatosis, and insulin intolerance. Raptor (Adipoq-cre) mice are also resistant to becoming obese when consuming a high fat diet (HFD). Resistance to obesity does not appear to be due to increased energy expenditure, but rather from failed adipose tissue expansion resulting in severe hepatomegaly associated with hyperphagia and defective dietary lipid absorption. Deleting Raptor in WAT also decreases C/EBPα expression and the expression of its downstream target adiponectin, providing one possible mechanism of mTORC1 function in WAT. CONCLUSIONS: mTORC1 activity in mature adipocytes is essential for maintaining normal adipose tissue growth and its selective loss in mature adipocytes leads to a progressive lipodystrophy disorder and systemic metabolic disease that shares many of the hallmarks of human congenital generalized lipodystrophy.

8.
Nat Commun ; 7: 11365, 2016 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-27098609

RESUMEN

Adipose tissue de novo lipogenesis (DNL) positively influences insulin sensitivity, is reduced in obesity, and predicts insulin resistance. Therefore, elucidating mechanisms controlling adipose tissue DNL could lead to therapies for type 2 diabetes. Here, we report that mechanistic target of rapamycin complex 2 (mTORC2) functions in white adipose tissue (WAT) to control expression of the lipogenic transcription factor ChREBPß. Conditionally deleting the essential mTORC2 subunit Rictor in mature adipocytes decreases ChREBPß expression, which reduces DNL in WAT, and impairs hepatic insulin sensitivity. Mechanistically, Rictor/mTORC2 promotes ChREBPß expression in part by controlling glucose uptake, but without impairing pan-AKT signalling. High-fat diet also rapidly decreases adipose tissue ChREBPß expression and insulin sensitivity in wild-type mice, and does not further exacerbate insulin resistance in adipose tissue Rictor knockout mice, implicating adipose tissue DNL as an early target in diet-induced insulin resistance. These data suggest mTORC2 functions in WAT as part of an extra-hepatic nutrient-sensing mechanism to control glucose homeostasis.


Asunto(s)
Tejido Adiposo Blanco/metabolismo , Proteínas Portadoras/genética , Hígado/metabolismo , Complejos Multiproteicos/genética , Proteínas Nucleares/genética , Obesidad/genética , Subunidades de Proteína/genética , Serina-Treonina Quinasas TOR/genética , Factores de Transcripción/genética , Adipocitos/metabolismo , Adipocitos/patología , Adipogénesis/genética , Tejido Adiposo Blanco/patología , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Proteínas Portadoras/metabolismo , Dieta Alta en Grasa/efectos adversos , Femenino , Eliminación de Gen , Regulación de la Expresión Génica , Glucosa/metabolismo , Resistencia a la Insulina/genética , Lipogénesis/genética , Hígado/patología , Masculino , Diana Mecanicista del Complejo 2 de la Rapamicina , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Complejos Multiproteicos/metabolismo , Proteínas Nucleares/metabolismo , Obesidad/etiología , Obesidad/metabolismo , Obesidad/patología , Subunidades de Proteína/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína Asociada al mTOR Insensible a la Rapamicina , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Factores de Transcripción/metabolismo
9.
Proc Natl Acad Sci U S A ; 112(48): 14876-81, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26578804

RESUMEN

Lysosomes are lined with a glycocalyx that protects the limiting membrane from the action of degradative enzymes. We tested the hypothesis that Niemann-Pick type C 1 (NPC1) protein aids the transfer of low density lipoprotein-derived cholesterol across this glycocalyx. A prediction of this model is that cells will be less dependent upon NPC1 if their glycocalyx is decreased in density. Lysosome cholesterol content was significantly lower after treatment of NPC1-deficient human fibroblasts with benzyl-2-acetamido-2-deoxy-α-D-galactopyranoside, an inhibitor of O-linked glycosylation. Direct biochemical measurement of cholesterol showed that lysosomes purified from NPC1-deficient fibroblasts contained at least 30% less cholesterol when O-linked glycosylation was blocked. As an independent means to modify protein glycosylation, we used Chinese hamster ovary ldl-D cells defective in UDP-Gal/UDP-GalNAc 4-epimerase in which N- and O-linked glycosylation can be controlled. CRISPR generated, NPC1-deficient ldl-D cells supplemented with galactose accumulated more cholesterol than those in which sugar addition was blocked. In the absence of galactose supplementation, NPC1-deficient ldl-D cells also transported more cholesterol from lysosomes to the endoplasmic reticulum, as monitored by an increase in cholesteryl [(14)C]-oleate levels. These experiments support a model in which NPC1 protein functions to transfer cholesterol past a lysosomal glycocalyx.


Asunto(s)
Colesterol/metabolismo , Fibroblastos/metabolismo , Glicocálix/metabolismo , Lisosomas/metabolismo , Glicoproteínas de Membrana/deficiencia , Animales , Transporte Biológico Activo/efectos de los fármacos , Transporte Biológico Activo/genética , Células CHO , Carbohidrato Epimerasas/genética , Carbohidrato Epimerasas/metabolismo , Proteínas Portadoras , Colesterol/genética , Cricetinae , Cricetulus , Fibroblastos/citología , Galactosa/análogos & derivados , Galactosa/farmacología , Glicocálix/genética , Glicosilación/efectos de los fármacos , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular , Lisosomas/genética , Proteína Niemann-Pick C1
10.
Elife ; 42015 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-25821985

RESUMEN

Most kinesins transport cargoes bound to their C-termini and use N-terminal motor domains to move along microtubules. We report here a novel function for KIF1C: it transports Rab6A-vesicles and can influence Golgi complex organization. These activities correlate with KIF1C's capacity to bind the Golgi protein Rab6A directly, both via its motor domain and C-terminus. Rab6A binding to the motor domain inhibits microtubule interaction in vitro and in cells, decreasing the amount of motile KIF1C. KIF1C depletion slows protein delivery to the cell surface, interferes with vesicle motility, and triggers Golgi fragmentation. KIF1C can protect Golgi membranes from fragmentation in cells lacking an intact microtubule network. Rescue of fragmentation requires sequences that enable KIF1C to bind Rab6A at both ends, but not KIF1C motor function. Rab6A binding to KIF1C's motor domain represents an entirely new mode of regulation for a kinesin motor, and likely has important consequences for KIF1C's cellular functions.


Asunto(s)
Aparato de Golgi/metabolismo , Cinesinas/química , Cinesinas/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Animales , Sitios de Unión , Chlorocebus aethiops , Aparato de Golgi/efectos de los fármacos , Células HEK293 , Células HeLa , Humanos , Ratones , Microtúbulos/efectos de los fármacos , Microtúbulos/metabolismo , Nocodazol/farmacología , Unión Proteica/efectos de los fármacos , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Transporte de Proteínas/efectos de los fármacos , Imagen de Lapso de Tiempo , Transfección , Células Vero
11.
Connect Tissue Res ; 55 Suppl 1: 48-52, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25158180

RESUMEN

Sea urchin's teeth from four families of order Echinoida and from orders Temnopleuroida, Arbacioida and Cidaroida were studied with synchrotron X-ray diffraction. The high and very high Mg calcite phases of the teeth, i.e. the first and second stage mineral constituents, respectively, have the same crystallographic orientations. The co-orientation of first and second stage mineral, which the authors attribute to epitaxy, extends across the phylogenic width of the extant regular sea urchins and demonstrates that this is a primitive character of this group. The range of compositions Δx for the two phases of Ca1-xMgxCO3 is about 0.20 or greater and is consistent with a common biomineralization process.


Asunto(s)
Carbonato de Calcio/química , Erizos de Mar/química , Diente/química , Animales , Procesamiento de Imagen Asistido por Computador , Erizos de Mar/ultraestructura , Diente/ultraestructura , Difracción de Rayos X
12.
Am J Pathol ; 179(3): 1338-46, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21855682

RESUMEN

Increased expression of the discoidin domain receptor 2 (DDR2) results from its interaction with collagen type II. This induces expression of matrix metalloproteinase (MMP)-13, leading to osteoarthritis (OA). To investigate the impact of the pericellular matrix of chondrocytes on DDR2, we generated a mouse model with inducible overexpression of DDR2 in cartilage. Conditional overexpression of DDR2 in mature mouse articular cartilage was controlled via the cartilage oligomeric matrix protein promoter using the Tet-Off-inducible system. Doxycycline was withdrawn at 1 month of age, and knee joints were examined at 2, 3, and 4 months of age. Microsurgery was performed on 3-month-old transgenic mice overexpressing DDR2 to destabilize the medial meniscus, and serial paraffin sections were examined at 2, 4, 8, and 12 weeks after surgery. DDR2 expression increased in the knee joints of transgenic mice. However, the increased DDR2 did not induce MMP-13 expression. No OA-like changes were observed in the transgenic mice at the age of 4 months. When transgenic mice were subjected to destabilizing of the medial meniscus, we observed accelerated progression to OA, which was associated with DDR2 activation. Therefore, conditionally overexpressing DDR2 in the mature articular cartilage of mouse knee joints requires activation to induce OA, and altered biomechanical stress can accelerate the onset of cartilage loss and progression to OA in transgenic mice.


Asunto(s)
Cartílago Articular/metabolismo , Metaloproteinasa 13 de la Matriz/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores Mitogénicos/metabolismo , Rodilla de Cuadrúpedos/metabolismo , Animales , Colágeno Tipo II/metabolismo , Colágeno Tipo IV , Receptores con Dominio Discoidina , Doxiciclina/farmacología , Inmunohistoquímica , Ratones , Ratones Transgénicos , Osteoartritis de la Rodilla/etiología , Osteoartritis de la Rodilla/metabolismo , ARN Mensajero/metabolismo , Transgenes
13.
J Am Chem Soc ; 132(44): 15496-8, 2010 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-20958035

RESUMEN

Scandium trifluoride maintains a cubic ReO(3) type structure down to at least 10 K, although the pressure at which its cubic to rhombohedral phase transition occurs drops from >0.5 GPa at ∼300 K to 0.1-0.2 GPa at 50 K. At low temperatures it shows strong negative thermal expansion (NTE) (60-110 K, α(l) ≈ -14 ppm K(-1)). On heating, its coefficient of thermal expansion (CTE) smoothly increases, leading to a room temperature CTE that is similar to that of ZrW(2)O(8) and positive thermal expansion above ∼1100 K. While the cubic ReO(3) structure type is often used as a simple illustration of how negative thermal expansion can arise from the thermally induced rocking of rigid structural units, ScF(3) is the first material with this structure to provide a clear experimental illustration of this mechanism for NTE.

14.
Arthritis Rheum ; 62(9): 2736-44, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20518074

RESUMEN

OBJECTIVE: To investigate whether the reduction of discoidin domain receptor 2 (DDR-2), a cell membrane tyrosine kinase receptor for native type II collagen, attenuates the progression of articular cartilage degeneration in mouse models of osteoarthritis (OA). METHODS: Double-heterozygous (type XI collagen-deficient [Col11a1(+/-)] and Ddr2-deficient [Ddr2(+/-)]) mutant mice were generated. Knee joints of Ddr2(+/-) mice were subjected to microsurgical destabilization of the medial meniscus. Conditions of the articular cartilage from the knee joints of the double-heterozygous mutant and surgically treated mice were examined by histology, evaluated using a modified Mankin scoring system, and characterized by immunohistochemistry. RESULTS: The rate of progressive degeneration in knee joints was dramatically reduced in the double-heterozygous mutant mice compared with that in the type XI collagen-deficient mice. The progression in the double-heterozygous mutant mice was delayed by ∼6 months. Following surgical destabilization of the medial meniscus, the progressive degeneration toward OA was dramatically delayed in the Ddr2(+/-) mice compared with that in their wild-type littermates. The articular cartilage damage present in the knee joints of the mice was directly correlated with the expression profiles of DDR-2 and matrix metalloproteinase 13. CONCLUSION: Reduction of DDR-2 expression attenuates the articular cartilage degeneration of knee joints induced either by type XI collagen deficiency or by surgical destabilization of the medial meniscus.


Asunto(s)
Osteoartritis/patología , Proteínas Tirosina Quinasas Receptoras/genética , Receptores Mitogénicos/genética , Animales , Cartílago Articular/metabolismo , Cartílago Articular/patología , Colágeno Tipo XI/deficiencia , Colágeno Tipo XI/genética , Receptores con Dominio Discoidina , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Técnica del Anticuerpo Fluorescente Indirecta , Técnicas para Inmunoenzimas , Meniscos Tibiales/cirugía , Ratones , Ratones Noqueados , Osteoartritis/genética , Osteoartritis/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores Mitogénicos/metabolismo , Rodilla de Cuadrúpedos/metabolismo , Rodilla de Cuadrúpedos/patología , Rodilla de Cuadrúpedos/cirugía
15.
Histol Histopathol ; 25(5): 599-608, 2010 05.
Artículo en Inglés | MEDLINE | ID: mdl-20238298

RESUMEN

This study is to investigate the possible role of high temperature requirement A 1 (HtrA1) in the articular cartilage degeneration. Paraffin sections were prepared from the knee and temporomandibular (TM) joints of four mouse OA models; two of the models had a genetic mutation (type IX collagen-deficient and type XI collagen-haploinsufficient) and two were surgically induced (destabilization of the medial meniscus of knee joint and discectomy of TM joint). The HtrA1 protein expression profiles of the prepared sections were examined by immunohistostaining. The level of HtrA1 mRNA in the articular cartilage taken from the knee joints of one of the genetically mutated OA models was determined by real-time PCR. Double immunohistostaining was used to examine the expression of co-localization of HtrA1 with type VI collagen and HtrA1 with discoidin domain receptor 2 (Ddr2) in the articular cartilage of knee joints from the genetically mutated OA model. The expression of HtrA1 was found to be increased in the knee and TM joints of these four models at early stages of the disease. An examination of the knee joint of a mutant mouse indicated an 8-fold increase in the level of HtrA1 mRNA, when compared to the levels observed in the knee joints of its wild-type littermates. Pericellular type VI collagen was not present in chondrocytes expressing HtrA1. Meanwhile, the expression of HtrA1 was associated with the expression of Ddr2 in the chondrocytes. Results indicate that HtrA1 may disrupt the pericellular matrix network, resulting in alteration of chondrocyte metabolisms. This eventually leads to OA.


Asunto(s)
Artritis Experimental/enzimología , Artritis Experimental/etiología , Cartílago Articular/enzimología , Osteoartritis/enzimología , Osteoartritis/etiología , Serina Endopeptidasas/metabolismo , Animales , Artritis Experimental/genética , Artritis Experimental/patología , Secuencia de Bases , Cartílago Articular/patología , Condrocitos/metabolismo , Colágeno Tipo IX/deficiencia , Colágeno Tipo IX/genética , Colágeno Tipo IX/metabolismo , Colágeno Tipo XI/deficiencia , Colágeno Tipo XI/genética , Colágeno Tipo XI/metabolismo , Cartilla de ADN/genética , Receptores con Dominio Discoidina , Perfilación de la Expresión Génica , Serina Peptidasa A1 que Requiere Temperaturas Altas , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Osteoartritis/genética , Osteoartritis/patología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores Mitogénicos/metabolismo , Serina Endopeptidasas/genética
16.
J Bacteriol ; 191(24): 7456-65, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19837801

RESUMEN

The Escherichia coli chromosome encodes seven demonstrated type 2 toxin-antitoxin (TA) systems: cassettes of two or three cotranscribed genes, one encoding a stable toxin protein that can cause cell stasis or death, another encoding a labile antitoxin protein, and sometimes a third regulatory protein. We demonstrate that the yafNO genes constitute an additional chromosomal type 2 TA system that is upregulated during the SOS DNA damage response. The yafNOP genes are part of the dinB operon, of which dinB underlies stress-induced mutagenesis mechanisms. yafN was identified as a putative antitoxin by homology to known antitoxins, implicating yafO (and/or yafP) as a putative toxin. Using phage-mediated cotransduction assays for linkage disruption, we show first that yafN is an essential gene and second that it is essential only when yafO is present. Third, yafP is not a necessary part of either the toxin or the antitoxin. Fourth, although DinB is required, the yafNOP genes are not required for stress-induced mutagenesis in the Escherichia coli Lac assay. These results imply that yafN encodes an antitoxin that protects cells against a yafO-encoded toxin and show a protein-based TA system upregulated by the SOS response.


Asunto(s)
Toxinas Bacterianas/antagonistas & inhibidores , Toxinas Bacterianas/toxicidad , Proteínas de Escherichia coli/metabolismo , Escherichia coli/fisiología , Respuesta SOS en Genética , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Proteínas de Escherichia coli/genética , Eliminación de Gen , Genes Esenciales , Viabilidad Microbiana
17.
Glycobiology ; 19(6): 655-64, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19261593

RESUMEN

Poly-N-acetyllactosamine (polyLacNAc) is a linear carbohydrate polymer composed of alternating N-acetylglucosamine and galactose residues involved in cellular functions ranging from differentiation to metastasis. PolyLacNAc also serves as a scaffold on which other oligosaccharides such as sialyl Lewis X are displayed. The polymerization of the alternating N-acetylglucosamine and galactose residues is catalyzed by the successive action of UDP-GlcNAc:betaGal beta-1,3-N-acetylglucosaminyltransferase 1 (B3GNT1) and UDP-Gal:betaGlcNAc beta-1,4-galactosyltransferase, polypeptide 1 (B4GALT1), respectively. The functional association between these two glycosyltransferases led us to investigate whether the enzymes also associate physically. We show that B3GNT1 and B4GALT1 colocalize by immunofluorescence microscopy, interact by coimmunoprecipitation, and affect each other's subcellular localization when one of the two proteins is artificially retained in the endoplasmic reticulum. These results demonstrate that B3GNT1 and B4GALT1 physically associate in vitro and in cultured cells, providing insight into possible mechanisms for regulation of polyLacNAc production.


Asunto(s)
Galactosiltransferasas/metabolismo , N-Acetilglucosaminiltransferasas/metabolismo , Polisacáridos/biosíntesis , Red trans-Golgi/enzimología , Animales , Células HeLa , Humanos , Transporte de Proteínas
18.
Rev Sci Instrum ; 79(8): 085105, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19044378

RESUMEN

A new dedicated high-resolution high-throughput powder diffraction beamline has been built, fully commissioned, and opened to general users at the Advanced Photon Source. The optical design and commissioning results are presented. Beamline performance was examined using a mixture of the NIST Si and Al(2)O(3) standard reference materials, as well as the LaB6 line-shape standard. Instrumental resolution as high as 1.7 x 10(-4) (DeltaQQ) was observed.

19.
J Synchrotron Radiat ; 15(Pt 5): 427-32, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18728312

RESUMEN

A dedicated high-resolution high-throughput X-ray powder diffraction beamline has been constructed at the Advanced Photon Source (APS). In order to achieve the goals of both high resolution and high throughput in a powder instrument, a multi-analyzer detector system is required. The design and performance of the 12-analyzer detector system installed on the powder diffractometer at the 11-BM beamline of APS are presented.


Asunto(s)
Difracción de Rayos X/métodos , Diseño de Equipo/métodos , Difracción de Polvo/métodos , Sincrotrones/instrumentación , Difracción de Rayos X/instrumentación
20.
J Synchrotron Radiat ; 15(Pt 5): 477-88, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18728319

RESUMEN

A GE Revolution 41RT flat-panel detector (GE 41RT) from GE Healthcare (GE) has been in operation at the Advanced Photon Source for over two years. The detector has an active area of 41 cm x 41 cm with 200 microm x 200 microm pixel size. The nominal working photon energy is around 80 keV. The physical set-up and utility software of the detector system are discussed in this article. The linearity of the detector response was measured at 80.7 keV. The memory effect of the detector element, called lag, was also measured at different exposure times and gain settings. The modulation transfer function was measured in terms of the line-spread function using a 25 microm x 1 cm tungsten slit. The background (dark) signal, the signal that the detector will carry without exposure to X-rays, was measured at three different gain settings and with exposure times of 1 ms to 15 s. The radial geometric flatness of the sensor panel was measured using the diffraction pattern from a CeO(2) powder standard. The large active area and fast data-capturing rate, i.e. 8 frames s(-1) in radiography mode, 30 frames s(-1) in fluoroscopy mode, make the GE 41RT one of a kind and very versatile in synchrotron diffraction. The loading behavior of a Cu/Nb multilayer material is used to demonstrate the use of the detector in a strain-stress experiment. Data from the measurement of various samples, amorphous SiO(2) in particular, are presented to show the detector effectiveness in pair distribution function measurements.

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