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1.
Plant Cell ; 36(9): 3751-3769, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-38943676

RESUMEN

The cell wall shapes plant cell morphogenesis and affects the plasticity of organ growth. However, the way in which cell wall establishment is regulated by ethylene remains largely elusive. Here, by analyzing cell wall patterns, cell wall composition and gene expression in rice (Oryza sativa, L.) roots, we found that ethylene induces cell wall thickening and the expression of cell wall synthesis-related genes, including CELLULOSE SYNTHASE-LIKE C1, 2, 7, 9, 10 (OsCSLC1, 2, 7, 9, 10) and CELLULOSE SYNTHASE A3, 4, 7, 9 (OsCESA3, 4, 7, 9). Overexpression and mutant analyses revealed that OsCSLC2 and its homologs function in ethylene-mediated induction of xyloglucan biosynthesis mainly in the cell wall of root epidermal cells. Moreover, OsCESA-catalyzed cellulose deposition in the cell wall was enhanced by ethylene. OsCSLC-mediated xyloglucan biosynthesis likely plays an important role in restricting cell wall extension and cell elongation during the ethylene response in rice roots. Genetically, OsCSLC2 acts downstream of ETHYLENE-INSENSITIVE3-LIKE1 (OsEIL1)-mediated ethylene signaling, and OsCSLC1, 2, 7, 9 are directly activated by OsEIL1. Furthermore, the auxin signaling pathway is synergistically involved in these regulatory processes. These findings link plant hormone signaling with cell wall establishment, broadening our understanding of root growth plasticity in rice and other crops.


Asunto(s)
Pared Celular , Etilenos , Regulación de la Expresión Génica de las Plantas , Glucosiltransferasas , Oryza , Proteínas de Plantas , Raíces de Plantas , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/metabolismo , Pared Celular/metabolismo , Etilenos/metabolismo , Glucosiltransferasas/metabolismo , Glucosiltransferasas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Raíces de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Glucanos/metabolismo , Xilanos/metabolismo , Celulosa/metabolismo
2.
Genomics ; 112(6): 5254-5264, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32976976

RESUMEN

The NAC transcription factor participates in various biotic and abiotic stress responses and plays a critical role in plant development. Lignin is a water-insoluble dietary fiber, but it is second only to cellulose in abundance. Celery is the main source of dietary fiber, but its quality and production are limited by various abiotic stresses. Here, AgNAC1 containing the NAM domain was identified from celery. AgNAC1 was found to be a nuclear protein. Transgenic Arabidopsis thaliana plants hosting AgNAC1 have longer root lengths and stomatal axis lengths than the wide type (WT). The evidence from lignin determination and expression levels of lignin-related genes indicated that AgNAC1 plays a vital role in lignin biosynthesis. Furthermore, the results of the physiological characterization and the drought and salt treatments indicate that AgNAC1-overexpressing plants are significantly resistive to salt stress. Under drought and salt treatments, the AgNAC1 transgenic Arabidopsis thaliana plants presented increased superoxide dismutase (SOD) and peroxidase (POD) activities and decreased malondialdehyde (MDA) content and size of stomatal apertures relatively to the WT plants. The AgNAC1 served as a positive regulator in inducing the expression of stress-responsive genes. Overall, the overexpressing AgNAC1 enhanced the plants' resistance to salt stress and played a regulatory role in lignin accumulation.


Asunto(s)
Apium , Lignina/biosíntesis , Proteínas de Plantas/fisiología , Tolerancia a la Sal/genética , Factores de Transcripción/fisiología , Apium/genética , Arabidopsis/anatomía & histología , Arabidopsis/genética , Arabidopsis/metabolismo , Sequías , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/anatomía & histología , Plantas Modificadas Genéticamente/metabolismo , Homología de Secuencia , Factores de Transcripción/química , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
3.
BMC Infect Dis ; 13: 383, 2013 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-23961958

RESUMEN

BACKGROUND: To clarify the molecular mechanisms that participate in the severe hand, foot and mouth disease (HFMD) infected by Enterovirus 71 and to detect any related protein biomarkers, we performed proteomic analysis of protein extracts from 5 extremely severe HFMD children and 5 healthy children. METHODS: The protein profiles of them were compared using two-dimensional electrophoresis. Differentially expressed proteins were identified using mass spectrometry. Functional classifications of these proteins were based on the PANTHER. The interaction network of the differentially expressed protein was generated with Pathway Studio. RESULTS: A total of 38 differentially expressed proteins were identified. Functional classifications of these proteins indicated a series of altered cellular processes as a consequence of the severe HFMD. These results provided not only new insights into the pathogenesis of severe HFMD, but also implications of potential therapeutic designs. CONCLUSIONS: Our results suggested the possible pathways that could be the potential targets for novel therapy: viral protection, complement system and peroxide elimination.


Asunto(s)
Enterovirus Humano A/aislamiento & purificación , Enfermedad de Boca, Mano y Pie/sangre , Proteoma/análisis , Proteínas Sanguíneas/análisis , Western Blotting , Electroforesis en Gel Bidimensional , Humanos , Mapas de Interacción de Proteínas , Proteómica , Reproducibilidad de los Resultados , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
4.
Zhong Yao Cai ; 36(6): 994-8, 2013 Jun.
Artículo en Zh | MEDLINE | ID: mdl-24380288

RESUMEN

OBJECTIVE: To optimize the extraction process and macroporous resin for purification of Timosaponin B II from Anemarrhena asphodeloides. METHODS: Orthogonal design L9 (34) was employed to optimize the circumfluence extraction conditions by taking the extraction yield of Timosaponin B II as index. The absorption-desorption characteristics of eight kinds of macroporous resins were evaluated, then the best resin was chosen to optimize the purification process conditions. RESULTS: The optimum extraction conditions were as follows: the herb was extracted for 2 times (2 hours each time) with 8.5-fold 50% ethanol at the first time and 6-fold 50% ethanol at the second time. HPD100 resin showed a good property for the absorption-desorption of Timosaponin B II. The optimum technological conditions of HPD100 resin were as follows:the solution concentration was 0.23 mg/mL, the amount of saturated adsorption at 4/5 body volumn (BV) resin, the HPD100 resin was washed with 3 BV water and 6 BV 20% ethanol solution to remove the impurity, then the Timosaponin B II was desorbed by 5 BV ethanol solution. The purity of Timosaponin B II was about 50%. CONCLUSION: The optimized extraction process and purification is stable, efficient and suitable for industrial production.


Asunto(s)
Anemarrhena/química , Resinas Sintéticas/química , Saponinas/aislamiento & purificación , Esteroides/aislamiento & purificación , Absorción , Cromatografía Líquida de Alta Presión , Etanol/química , Plantas Medicinales/química , Rizoma/química , Saponinas/química , Esteroides/química , Tecnología Farmacéutica/métodos , Factores de Tiempo
5.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 34(4): 359-63, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22954118

RESUMEN

OBJECTIVE: To explore the podocyte injury in patients with diabetic nephropathy (DN) and analyze its relationship with glucose regulated protein 78 (GRP78) and proteinuria. METHODS: The clinical data of 48 patients diagnosed as DN by renal biopsy were reviewed. All patients were divided into two groups according to proteinuria (>3.5 g/d, n=31 and 3.5 g/d, n=17). The density of podocytes was illustrated by immunohistochemistry staining of Wilms tumor-1 (WT-1), and the immunofluorescence double-staining results of synaptopodin and GRP78 in podocytes were detected. RESULTS: The podocyte dentistry of urine protein > 3.5 g/d group was significantly lower than that of urine protein>3.5 g/d group urine protein<3.5 g/d group(P=0.003), and it was negatively correlated with proteinuria (P=0.005). The expressions of synaptopodin and GRP78 in podocytes were also negatively correlated with proteinuria (P=0.004 and P=0.001). CONCLUSION: The podocyte injury is aggravated with increased proteinuria in DN patients, along with the decrease of the adaptive ability of endoplasmic reticulum to stress.


Asunto(s)
Nefropatías Diabéticas/patología , Proteínas de Choque Térmico/metabolismo , Podocitos/patología , Proteinuria/etiología , Adulto , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/metabolismo , Chaperón BiP del Retículo Endoplásmico , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
Zhong Yao Cai ; 34(4): 623-7, 2011 Apr.
Artículo en Zh | MEDLINE | ID: mdl-21809551

RESUMEN

OBJECTIVE: To optimize the process for purification of geniposide in the extract fluid of Gardenia jasminoides with macroporous absorption resin. METHODS: By comparing the content and transfer ratio of geniposide during the process of purification, we optimized the process for purification of geniposide. RESULTS: The optimal process for purification of geniposide with D301R macroporous absorption resin included the diameter height ratio 1:7.5, the concentration of the extract fluid of Gardenia jasminoides 2:1, the flow rate 1BV/h (1BV represented one column volume), the sample volume 1/3BV. We loaded the sample and left it for 2 hours, afterwards, rinsed the macroporous absorption resin using 2BV water until the solution became colourless. Then we rinsed the macroporous absorption resin with 20% alcohol,and the volume of elution solvent was 2BV. We collected 20% alcohol elution solvent and recycle alcohol using rotating evaporation and dried the rest solution in a vacuum to get the light yellow powder which was the purified geniposide. CONCLUSION: This process is simple and affordable, can be used to refine and purify geniposide in the extract fluid of Gardenia jasminoides Ellis. It provides a guidance for industrial production basis.


Asunto(s)
Gardenia/química , Iridoides/aislamiento & purificación , Resinas Sintéticas/química , Tecnología Farmacéutica/métodos , Absorción , Cromatografía Líquida de Alta Presión/métodos , Frutas/química , Iridoides/análisis , Reproducibilidad de los Resultados , Solventes
7.
Am J Physiol Lung Cell Mol Physiol ; 299(6): L794-807, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20870746

RESUMEN

Surfactant protein A (SP-A) plays an important role in the maintenance of lung lipid homeostasis. Previously, an SP-A receptor, P63 (CKAP4), on type II pneumocyte plasma membranes (PM) was identified by chemical cross-linking techniques. An antibody to P63 blocked the specific binding of SP-A to pneumocytes and the ability of SP-A to regulate surfactant secretion. The current report shows that another biological activity of SP-A, the stimulation of surfactant uptake by pneumocytes, is inhibited by P63 antibody. cAMP exposure resulted in enrichment of P63 on the cell surface as shown by stimulation of SP-A binding, enhanced association of labeled P63 antibody with type II cells, and promotion of SP-A-mediated liposome uptake, all of which were inhibited by competing P63 antibody. Incubation of A549 and type II cells with SP-A also increased P63 localization on the PM. The phosphatidylinositol 3-kinase (PI3-kinase) signaling pathway was explored as a mechanism for the transport of this endoplasmic reticulum (ER)-resident protein to the PM. Treatment with LY-294002, an inhibitor of the PI3-kinase pathway, prevented the SP-A-induced PM enrichment of P63. Exposure of pneumocytes to SP-A or cAMP activated Akt (PKB). Blocking either PI3-kinase or Akt altered SP-A-mediated lipid turnover. The data demonstrate an important role for the PI3-kinase-Akt pathway in intracellular transport of P63. The results add to the growing body of evidence that P63 is critical for SP-A receptor-mediated interactions with type II pneumocytes and the resultant regulation of surfactant turnover.


Asunto(s)
Células Epiteliales Alveolares/metabolismo , Proteínas de la Membrana/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Proteína A Asociada a Surfactante Pulmonar/metabolismo , Receptores de Superficie Celular/metabolismo , Transducción de Señal/fisiología , Células Epiteliales Alveolares/citología , Animales , Membrana Celular/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Activación Enzimática , Inhibidores Enzimáticos/metabolismo , Humanos , Liposomas/química , Liposomas/metabolismo , Proteínas de la Membrana/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Receptores de Superficie Celular/genética
8.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 31(3): 362-4, 2009 Jun.
Artículo en Zh | MEDLINE | ID: mdl-19621526

RESUMEN

OBJECTIVE: To explore the effect of low-flux polysulphone membranes on the serum levels of inflammatory cytokines, hyper-sensitivity C reactive protein (hsCRP), lipoprotein (a) [Lp (a)], and beta2 microglobulin (beta 2MG) in hemodialysis patients. METHODS: The blood samples and dialysate samples were collected at pre-dialysis, 120 minutes later during the session, and post-dialysis in 27 stable hemodialysis patients. Variables determined included serum Lp (a), hsCRP, interleukin (IL)-1 beta, IL-6, and beta 2MG. The endotoxin levels were also detected. RESULTS: There were no significant changes either in endotoxin level of dialysate or in all variables tested during one session (P > 0.05). CONCLUSION: Low-flux polysulphone membrane has no effects on serum Lp (a), hsCRP, IL-1 beta, IL-6, and beta 2MG during one session in hemodialysis patients.


Asunto(s)
Membranas Artificiales , Polímeros , Diálisis Renal , Sulfonas , Adulto , Anciano , Proteína C-Reactiva/metabolismo , Femenino , Humanos , Interleucina-1beta/sangre , Interleucina-6/sangre , Lipoproteína(a)/sangre , Masculino , Persona de Mediana Edad , Microglobulina beta-2/sangre
9.
Sci Total Environ ; 655: 1279-1287, 2019 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-30577120

RESUMEN

Suspended microbes gradually lost advantages in practical applications of PAHs and heavy metals bioremediation. Therefore this study investigated the effect of immobilization on phenanthrene degradation by Bacillus sp. P1 in the presence of different Cd(II) concentrations. Condensed Bacillus sp. P1 was immobilized with polyvinyl alcohol and sodium alginate and PVA-SA-cell cryogel beads were prepared. The results indicated that the use of gel beads increased the number of adsorption sites thus accelerating phenanthrene degradation. In addition, changes in detoxification indices, including superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), were determined to elucidate the immobilization mechanisms related to cells protection from Cd(II) when degrading phenanthrene. By protecting the gel membrane, oxidative damage was minimized, while SOD activity increased from 55.72 to 81.33 U/mgprot as Cd(II) increased from 0 to 200 mg/L but later dropped to 44.29 U/mgprot as Cd(II) increased to 300 mg/L for the non-immobilized system. On the other hand, the SOD activity kept increasing from 52.23 to 473.35 U/mgprot for the immobilized system exposed to Cd(II) concentration between 0 and 300 mg/L. For CAT and GSH, immobilization only slowed down the depletion process without any change on the variation trends. The changes in surface properties and physiological responses of microbes caused the differences of immobilization effect on phenanthrene biodegradation in the presence of Cd(II), which is a novel finding.


Asunto(s)
Bacillus/metabolismo , Cadmio/metabolismo , Contaminantes Ambientales/metabolismo , Fenantrenos/metabolismo , Adsorción , Alginatos/química , Inactivación Metabólica , Alcohol Polivinílico/química
10.
Sci Rep ; 7: 45630, 2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28422128

RESUMEN

Epidemiology and etiology of hand, foot, and mouth disease (HFMD) based on large sample size or evaluation of detection for more enterovirus serotypes are not well investigated in Chongqing of China. 45,616 suspect HFMD patients were prospectively enrolled among whom 21,615 were laboratory confirmed HFMD cases over a 5-year period (January 2011 to December 2015). Their epidemiological, clinical, and laboratory data were extracted and stratified by month, age, sex, disease severity, and enterovirus serotype. Subsequently 292 non-EV-A71/CV-A16 HFMD confirmed cases were randomly selected in three consecutive outbreaks to detect CV-A6 and CV-A10, using RT-PCR. Results showed that the HFMD epidemic peaked in early summer and autumn. The median age of onset was 2.45 years with a male-to-female ratio of 1.54:1, and with children under 5 years of age accounting for 92.54% of all confirmed cases. EV-A71 and CV-A16 infection accounted for only 36.05% (7793/21615) of total confirmed cases while EV-A71 accounted for 59.64% (232/389) of severe cases. Importantly, the proportion of EV-A71 infection generally increased with age which showed rapid growth in severe cases. CV-A6 and CV-A10 were tested positive in Chongqing, but CV-A6 had greater positive rates of 62.33% while CV-A10 had 4.79% in non-EV-A71/CV-A16 HFMD confirmed cases.


Asunto(s)
Brotes de Enfermedades , Enterovirus/clasificación , Enterovirus/aislamiento & purificación , Enfermedad de Boca, Mano y Pie/epidemiología , Serogrupo , Distribución por Edad , China/epidemiología , Enfermedad de Boca, Mano y Pie/patología , Enfermedad de Boca, Mano y Pie/virología , Humanos , Estudios Prospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estaciones del Año , Distribución por Sexo
12.
PLoS One ; 7(5): e38341, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22675455

RESUMEN

Environmentally Degradable Parameter ((Ed)K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept (Ed)K was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated (Ed)K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the (Ed)K values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of (Ed)K for each material. The (Ed)K values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the (Ed)K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment.


Asunto(s)
Polímeros/metabolismo , Algoritmos , Biodegradación Ambiental , Reactores Biológicos , Dióxido de Carbono/metabolismo , Polietileno/metabolismo , Suelo/química , Almidón/metabolismo
13.
Shanghai Kou Qiang Yi Xue ; 21(2): 130-3, 2012 Apr.
Artículo en Zh | MEDLINE | ID: mdl-22610318

RESUMEN

PURPOSE: To study the influence of TiO2 and methacrylic acid on self-cleaning and antimicrobial properties of denture base resin. METHODS: TiO2 (2%, 4%, 6%) and methacrylic acid were respectively added into two makers' denture base resins. The self-cleaning property was assayed with measuring the decomposition of methylthioninium chloride. The antimicrobial property was tested with the pellicle-sticking method. The data were analysed by SPSS 12.0 software package for two-way ANOVA. RESULTS: The self-cleaning and antimicrobial properties of samples were improved as TiO2 increased. Methacrylic acid had no significant influence on self-cleaning and antimicrobial properties of the samples. The decomposition ratio and antimicrobial ratio of MTi4% (Rijin) were 53.96% and 71.42%, respectively. CONCLUSION: Methacrylic acid coupled TiO2/PMMA denture base resin enjoys good self-cleaning and antimicrobial properties.


Asunto(s)
Bases para Dentadura , Polimetil Metacrilato , Antiinfecciosos , Metacrilatos
14.
Chin Med J (Engl) ; 124(21): 3490-4, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22340164

RESUMEN

BACKGROUND: Cyclosporine is effective in treating nephrotic syndrome (NS) with idiopathic membranous nephropathy (IMN) in adults. But high relapse rate remains a major concern. The way to manipulate cyclosporine is inconclusive. The aim of this study was to introduce the way how to titrate the cyclosporine to maintain complete remission without relapse. METHODS: Patients with biopsy-proven IMN with NS treated with cyclosporine for at least 1 month from 1996 to 2011 at Peking Union Medical College Hospital were reviewed. RESULTS: Mean age of the 51 eligible patients was 52 years, with 39 men. Mean proteinuria was (7.47 ± 3.14) g/d, serum albumin (24.50 ± 6.29) g/L, and serum creatinine (82.62 ± 21.18) mmol/L. Cyclosporine was commenced at a mean dose of (3.46 ± 0.63) mg×kg(-1)×d(-1). Oral prednisone (0.40 ± 0.29) mg×kg(-1)×d(-1) was given concomitantly in 38 patients. Cyclosporine was administered for a median of 16 months (range 1 - 93 months) and stopped in non-responders by month six. By month 3 (n = 47), the number in complete remission (CR) and partial remission (PR) was 3 and 24, which shifted to 12 and 17 by month 6 (n = 41). Male gender, heavy proteinuria, low serum albumin level, and high serum creatinine level were significant determinants in poor response by month six (P < 0.05 in all variables compared with responders). There was a significant reversible serum creatinine increase within 25% during month 3 to 12 (P < 0.05 in all variables compared with baseline value). Eleven patients maintained cyclosporine for more than 24 months with a cyclosporine dose of (1.04 ± 1.06) mg×kg(-1)×d(-1). Nine patients were in CR. Renal function, systolic and diastolic blood pressure remained stable. Renal impairment (> 30% rise of serum creatinine), secondary infection, hypertension, gingival hyperplasia and liver impairment occurred in 6, 4, 10, 4, and 1 patients, respectively. CONCLUSIONS: The observation time for cyclosporine to effectively induce CR of NS in IMN adults should be at least six months. Long-term and low-dose of cyclosporine therapy is safe and effective to maintain CR in those responders.


Asunto(s)
Ciclosporina/uso terapéutico , Glomerulonefritis Membranosa/tratamiento farmacológico , Inmunosupresores/uso terapéutico , Síndrome Nefrótico/tratamiento farmacológico , Adulto , Anciano , Ciclosporina/efectos adversos , Femenino , Humanos , Inmunosupresores/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
15.
Am J Physiol Lung Cell Mol Physiol ; 294(2): L325-33, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18083768

RESUMEN

Previous studies with the isolated perfused rat lung showed that both clathrin- and actin-mediated pathways are responsible for endocytosis of dipalmitoylphosphatidylcholine (DPPC)-labeled liposomes by granular pneumocytes in the intact lung. Using surfactant protein-A (SP-A) gene-targeted mice, we examined the uptake of [(3)H]DPPC liposomes by isolated mouse lungs under basal and secretagogue-stimulated conditions. Unilamellar liposomes composed of [(3)H]DPPC: phosphatidylcholine:cholesterol:egg phosphatidylglycerol (10:5:3:2 mol fraction) were instilled into the trachea of anesthetized mice, and the lungs were perfused (2 h). Uptake was calculated as percentage of instilled disintegrations per minute in the postlavaged lung. Amantadine, an inhibitor of clathrin and, thus, receptor-mediated endocytosis via clathrin-coated pits, decreased basal [(3)H]DPPC uptake by 70% in SP-A +/+ but only by 20% in SP-A -/- lung, data compatible with an SP-A/receptor-regulated lipid clearance pathway in the SP-A +/+ mice. The nonclathrin, actin-dependent process was low in the SP-A +/+ lung but accounted for 55% of liposome endocytosis in the SP-A -/- mouse. With secretagogue (8-bromoadenosine 3',5'-cyclic monophosphate) treatment, both clathrin- and actin-dependent lipid clearance were elevated in the SP-A +/+ lungs while neither pathway responded in the SP-A -/- lungs. Binding of iodinated SP-A to type II cells isolated from both genotypes of mice was similar indicating a normal SP-A receptor status in the SP-A -/- lung. Inclusion of SP-A with instilled liposomes served to "rescue" the SP-A -/- lungs by reestablishing secretagogue-dependent enhancement of liposome uptake. These data are compatible with a major role for receptor-mediated endocytosis of DPPC by granular pneumocytes, a process critically dependent on SP-A.


Asunto(s)
Marcación de Gen , Proteína A Asociada a Surfactante Pulmonar/deficiencia , Proteína A Asociada a Surfactante Pulmonar/metabolismo , Surfactantes Pulmonares/metabolismo , 1,2-Dipalmitoilfosfatidilcolina/metabolismo , Actinas/metabolismo , Animales , Separación Celular , Células Cultivadas , Colina/metabolismo , Clatrina/metabolismo , Citocalasina D/farmacología , Técnicas In Vitro , Radioisótopos de Yodo , Liposomas , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Perfusión , Unión Proteica/efectos de los fármacos , Alveolos Pulmonares/efectos de los fármacos , Alveolos Pulmonares/metabolismo , Tritio
16.
Am J Physiol Lung Cell Mol Physiol ; 285(5): L1055-65, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12882765

RESUMEN

Surfactant secretion by lung type II cells occurs when lamellar bodies (LBs) fuse with the plasma membrane and surfactant is released into the alveolar lumen. Surfactant protein A (SP-A) blocks secretagogue-stimulated phospholipid (PL) release, even in the presence of surfactant-like lipid. The mechanism of action is not clear. We have shown previously that an antibody to LB membranes (MAb 3C9) can be used to measure LB membrane trafficking. Although the ATP-stimulated secretion of PL was blocked by SP-A, the cell association of iodinated MAb 3C9 was not altered, indicating no effect on LB movement. FM1-43 is a hydrophobic dye used to monitor the formation of fusion pores. After secretagogue exposure, the threefold enhancement of the number of FM1-43 fluorescent LBs (per 100 cells) was not altered by the presence of SP-A. Finally, there was no evidence of a large PL pool retained on the cell surface through interaction with SP-A. Thus SP-A exposure does not affect these stages in the surfactant secretory pathway of type II cells.


Asunto(s)
Pulmón/metabolismo , Proteína A Asociada a Surfactante Pulmonar/metabolismo , Proteína A Asociada a Surfactante Pulmonar/farmacología , Proteínas Asociadas a Surfactante Pulmonar/metabolismo , Adenosina Trifosfato/farmacología , Animales , Productos Biológicos/farmacología , Líquido del Lavado Bronquioalveolar/química , Membrana Celular/fisiología , Células Cultivadas , Cinética , Liposomas/farmacología , Pulmón/efectos de los fármacos , Masculino , Fosfolípidos/metabolismo , Fosfolípidos/farmacología , Alveolos Pulmonares/efectos de los fármacos , Alveolos Pulmonares/fisiología , Ratas , Ratas Sprague-Dawley
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