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1.
Ocul Immunol Inflamm ; : 1-7, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37505627

RESUMEN

OBJECTIVE: To analyze the effect of gentamicin in the irrigating solution on endophthalmitis caused by methicillin-resistant Staphylococcus epidermidis after phacoemulsification with intraocular lens implantation. METHODS: Fifteen rabbits were randomly assigned into three groups. During surgery, group A was irrigated with gentamicin-free solution and injected with 100 µL of normal saline postoperatively, group B was irrigated with 80 µg/mL gentamicin and injected with 100 µl of MRSE suspension, group C was irrigated with gentamicin-free solution and injected with 100 µl of MRSE suspension. At different times, corneal endothelial cell count (CEC), inflammation grading,B-scan ultrasonography and histological examination were analyzed. RESULTS: No endophthalmitis occurred in groups A and B. Group C developed severe endophthalmitis, with massive inflammatory exudation in the vitreous cavity. CONCLUSION: Irrigating solution containing gentamicin is favorable to reduce the incidence of MRSE endophthalmitis after phacoemulsification with IOL in rabbits.

2.
BMC Ophthalmol ; 22(1): 410, 2022 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-36274140

RESUMEN

OBJECTIVE: To evaluate the effect of gentamicin in surgical perfusion solution on endophthalmitis incidence after cataract surgery. METHODS: A retrospective analysis of endophthalmitis incidence was conducted in two groups of patients who underwent cataract surgery, with (Group B) or without gentamicin (Group A) in the surgical perfusion solution. Endophthalmitis incidence, the isolated pathogenic bacteria strains and their antibiotic sensitivity, and the drug-resistant genotype of the pathogens were examined. RESULTS: The incidence of endophthalmitis in patients of group A was 0.8‰. Thirteen pathogenic bacterial strains were isolated from the patient samples in group A, including 8 strains of Staphylococcus epidermidis, 1 Staphylococcus aureus, 1 Streptococcus pneumoniae, 1 Streptococcus bovis, 1 Enterococcus faecium and 1 Morganella sp. The incidence of endophthalmitis in group B patients was 0.2‰, which was significantly lower than that in group A (P<0.05). Five strains of pathogenic bacteria were successfully isolated, including 2 strains of Enterococcus faecium, 1 Enterococcus faecalis, 1 Staphylococcus epidermidis and 1 Staphylococcus aureus. There was no significant difference in the proportion of Staphylococcus strains in all isolated bacteria between the two groups (P > 0.05). However, the proportion of Enterococci isolated in group B samples was higher than that in group A (P < 0.05). There were more gentamicin-sensitive strains than levofloxacin-sensitive strains identified (P < 0.05). Interestingly, aminoglycoside-inactivating enzyme resistance gene was detected in Enterococcus strains. CONCLUSION: Our data suggest that gentamicin-containing perfusion solution can reduce the incidence of postoperative endophthalmitis in cataract patients. However, the selective pressure imposed by gentamicin may facilitate the development of aminoglycoside-resistant Enterococcos strains.


Asunto(s)
Catarata , Endoftalmitis , Infecciones Estafilocócicas , Humanos , Gentamicinas/farmacología , Levofloxacino/farmacología , Pruebas de Sensibilidad Microbiana , Estudios Retrospectivos , Endoftalmitis/epidemiología , Endoftalmitis/prevención & control , Endoftalmitis/tratamiento farmacológico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/prevención & control , Infecciones Estafilocócicas/tratamiento farmacológico , Aminoglicósidos/farmacología , Staphylococcus aureus , Bacterias , Catarata/tratamiento farmacológico , Perfusión
3.
Ocul Immunol Inflamm ; 30(7-8): 1568-1571, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34003704

RESUMEN

PURPOSE: To alert clinicians to an uncommon presentation of iris metastasis of esophageal carcinoma. We reported a 67-year-old man complained of blurred vision and ocular pain of his right eye for 1 month. He was diagnosed iridocyclitis of the right eye 2 weeks ago and he had a history of esophageal squamous cell carcinoma for 5 years with no regular treatment. Under slit-lamp microscopy, accumulating snowflakes-like deposits were found in the anterior chamber of the right eye. Ocular metastasis was then confirmed by atypical cells in the aqueous humor and positron emission tomography (PET-CT). METHODS: Retrospective review of a case note and review of literature. CONCLUSION: We presented a rare case of iris metastasis of esophageal carcinoma and highlighted the importance of maintaining suspicion for metastasis in any elderly patients with uveitis, since the diseases masquerading as uveitis are not only vision threatening but may be potentially fatal.


Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Humanos , Anciano , Neoplasias Esofágicas/diagnóstico , Tomografía Computarizada por Tomografía de Emisión de Positrones , Iris
4.
Front Oncol ; 11: 703318, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34235088

RESUMEN

ROS1 rearrangements have been identified as driver mutations, accounting for 1-2% of lung adenocarcinoma, but are extremely rare in case of lung squamous cell carcinoma. In this work, we report a lung squamous cell carcinoma in a patient with peripheral lung cancer radiological manifestation, harboring ROS1 rearrangement, with high sensitivity to crizotinib. Our findings suggest that clinicians should pay more attention toward the occurrence of ROS1 rearrangements and the application of crizotinib for lung squamous cell carcinoma treatment.

5.
Nat Med ; 26(9): 1468-1479, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32778827

RESUMEN

PD-1 blockade is highly effective in classical Hodgkin lymphomas (cHLs), which exhibit frequent copy-number gains of CD274 (PD-L1) and PDC1LG2 (PD-L2) on chromosome 9p24.1. However, in this largely MHC-class-I-negative tumor, the mechanism of action of anti-PD-1 therapy remains undefined. We utilized the complementary approaches of T cell receptor (TCR) sequencing and cytometry by time-of-flight analysis to obtain a peripheral immune signature of responsiveness to PD-1 blockade in 56 patients treated in the CheckMate 205 phase II clinical trial (NCT02181738). Anti-PD-1 therapy was most effective in patients with a diverse baseline TCR repertoire and an associated expansion of singleton clones during treatment. CD4+, but not CD8+, TCR diversity significantly increased during therapy, most strikingly in patients who had achieved complete responses. Additionally, patients who responded to therapy had an increased abundance of activated natural killer cells and a newly identified CD3-CD68+CD4+GrB+ subset. These studies highlight the roles of recently expanded, clonally diverse CD4+ T cells and innate effectors in the efficacy of PD-1 blockade in cHL.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Enfermedad de Hodgkin/tratamiento farmacológico , Células Asesinas Naturales/inmunología , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Antineoplásicos Inmunológicos/uso terapéutico , Linfocitos T CD4-Positivos/clasificación , Linfocitos T CD8-positivos/clasificación , Humanos , Activación de Linfocitos/inmunología , Nivolumab/uso terapéutico , Receptores de Antígenos de Linfocitos T/genética , Microambiente Tumoral/inmunología
6.
J Vis Exp ; (160)2020 06 05.
Artículo en Inglés | MEDLINE | ID: mdl-32568239

RESUMEN

Quantitatively determining the Chladni pattern of an elastic plate is of great interest in both physical science and engineering applications. In this paper, a method of measuring mode shapes of a vibrating plate based on an optical lever method is proposed. Three circular acrylic plates were employed in the measurement under different center harmonic excitations. Different from a traditional method, only an ordinary laser pen and a light screen made of ground glass are employed in this novel approach. The approach is as follows: the laser pen projects a beam to the vibrating plate perpendicularly, and then the beam is reflected to the light screen in the distance, on which a line segment made of the reflected spot is formed. Due to the principle of vision persistence, the light spot could be read as a bright straight line. The relationship between the slope of the mode shape, length of the light spot and the distance of the vibrating plate and the light screen can be obtained with algebraic operations. Then the mode shape can be determined by integrating the slope distribution with suitable boundary conditions. The full-field mode shapes of Chladni plate could also be determined further in such a simple way.


Asunto(s)
Forma de la Célula/fisiología , Luz
8.
PLoS One ; 14(10): e0213482, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31600200

RESUMEN

Transforming growth factor­ß1 (TGF-ß1) is a versatile cytokine. It has context-dependent pro- and anti-cell proliferation functions. Activation of latent TGF-ß1 requires release of the growth factor from pro-complexes and is regulated through TGF-ß binding proteins. Two types of TGF-ß binding partners, latent TGF-ß-binding proteins (LTBPs) and leucine-rich-repeat-containing protein 32 (LRRC32), have been identified and their expression are cell specific. TGF-ß1 also plays important roles in acute myeloid leukemia (AML) cells. However, the expression of LTBPs and LRRC32 are lacking in myeloid lineage cells and the binding protein of TGF-ß1 in these cells are unknown. Here we show that a novel leucine-rich-repeat-containing protein family member, LRRC33, with high mRNA level in AML cells, to be the binding and regulating protein of TGF-ß1 in AML cells. Using two representative cell lines MV4-11 and AML193, we demonstrate that the protein expression of LRRC33 and TGF-ß1 are correlated. LRRC33 co-localizes and forms complex with latent TGF-ß1 protein on the cell surface and intracellularly in these cells. Similar as in other cell types, the activation of TGF-ß1 in MV4-11 and AML193 cells are also integrin dependent. We anticipate our study to be a starting point of more comprehensive research on LRRC33 as novel TGF-ß regulating protein and potential non-genomic based drug target for AML and other myeloid malignancy.


Asunto(s)
Proteínas de Unión a TGF-beta Latente/metabolismo , Leucemia Mieloide Aguda/metabolismo , Proteínas de Neoplasias/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Humanos , Proteínas de Unión a TGF-beta Latente/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Proteínas de Neoplasias/genética , Unión Proteica , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Factor de Crecimiento Transformador beta1/genética
10.
Cell ; 174(1): 156-171.e16, 2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-29909984

RESUMEN

Extracellular proTGF-ß is covalently linked to "milieu" molecules in the matrix or on cell surfaces and is latent until TGF-ß is released by integrins. Here, we show that LRRC33 on the surface of microglia functions as a milieu molecule and enables highly localized, integrin-αVß8-dependent TGF-ß activation. Lrrc33-/- mice lack CNS vascular abnormalities associated with deficiency in TGF-ß-activating integrins but have microglia with a reactive phenotype and after 2 months develop ascending paraparesis with loss of myelinated axons and death by 5 months. Whole bone marrow transplantation results in selective repopulation of Lrrc33-/- brains with WT microglia and halts disease progression. The phenotypes of WT and Lrrc33-/- microglia in the same brain suggest that there is little spreading of TGF-ß activated from one microglial cell to neighboring microglia. Our results suggest that interactions between integrin-bearing cells and cells bearing milieu molecule-associated TGF-ß provide localized and selective activation of TGF-ß.


Asunto(s)
Proteínas Portadoras/metabolismo , Microglía/metabolismo , Sistema Nervioso/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Animales , Axones/metabolismo , Trasplante de Médula Ósea , Encéfalo/metabolismo , Proteínas Portadoras/clasificación , Proteínas Portadoras/genética , Células Cultivadas , Integrinas/metabolismo , Estimación de Kaplan-Meier , Macrófagos/citología , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microglía/citología , Mutagénesis Sitio-Dirigida , Enfermedades Neurodegenerativas/mortalidad , Enfermedades Neurodegenerativas/patología , Enfermedades Neurodegenerativas/terapia , Filogenia , Unión Proteica , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Factor de Crecimiento Transformador beta/genética
11.
Technol Health Care ; 26(S1): 135-143, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29710746

RESUMEN

BACKGROUND: Laser therapy is reported to be clinically effective for improving microcirculation, rheological properties and blood lipid profiles despite the lack of certainty on the mechanism. OBJECTIVE: This study intends to provide methods to drop blood lipid level of hyperlipidemia samples by low-intensity laser irradiation therapy and provide reasoning of mechanism. METHODS: Twenty whole blood samples of high level of lipids profile are irradiated by 405 nm low-intensity laser at 12 J/cm2 twice a day for 3 days and compared with normal lipids profile group. Then whole blood sample are centrifuged to obtain result of erythrocyte for further interpretation. Multi-scan spectrum microplate reader is used to measure absorption spectrum and data is analyzed by software SPSS 14.0. RESULTS: Results show that after 405 nm low-intensity laser irradiation, whole blood samples of high lipid level statistically have higher absorbance peak value than normal samples while erythrocyte samples have lower absorbance peak value. CONCLUSIONS: From the divergence of absorption peak value change after low-intensity laser irradiation for whole blood sample and erythrocyte, we suspect that low level laser irradiation affects the enzymes activity of lipid metabolism, improves the cholesterol balance of plasma and cytoplasm in erythrocyte, and decreases aggregation of the erythrocyte.


Asunto(s)
Eritrocitos/efectos de la radiación , Hiperlipidemias/radioterapia , Terapia por Luz de Baja Intensidad/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Análisis Espectral
12.
BMC Ophthalmol ; 16: 116, 2016 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-27435453

RESUMEN

BACKGROUND: Vitamin D deficiency and vitamin D receptor gene polymorphisms are known to be significantly associated with high myopia. Whether this genetic variant may impact primary open-angle glaucoma is largely unknown. This study investigated whether vitamin D receptor gene polymorphisms are altered in primary open-angle glaucoma subjects carrying the risk allele, and whether vitamin D deficiency is an important factor in the development of glaucoma. METHODS: Seventy-three POAG patients and 71 age-matched controls from the Han population were enrolled. Serum levels of 1a, 25-Dihydroxyvitamin D3 were measured by enzyme-linked immunoabsorbent assay. Vitamin D receptor polymorphisms (Cdx-2, Fok I, Bsm I and Taq I) were analyzed using real-time polymerase-chain reaction high resolution melting analysis. RESULTS: Serum levels of 1a, 25-Dihydroxyvitamin in primary open-angle glaucoma patients were lower than in age-matched controls. Statistical analysis revealed a significant difference in the allelic frequencies of the BsmI and TaqI genotypes between primary open-angle glaucoma patients and age-matched controls, while other polymorphisms did not show any significant differences. CONCLUSIONS: Vitamin D deficiency and the presence of the BsmI 'B' allele and the TaqI 't' allele are relevant risk factors in the development of glaucoma. TRIAL REGISTRATION: Clinical Trials.gov: NCT02539745 . The study was registered retrospectively on August 3rd, 2015. The first participant was enrolled on July 4th, 2013.


Asunto(s)
Glaucoma de Ángulo Abierto/genética , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Deficiencia de Vitamina D/genética , Anciano , Alelos , Factor de Transcripción CDX2/genética , Estudios de Casos y Controles , Femenino , Frecuencia de los Genes , Genotipo , Glaucoma de Ángulo Abierto/sangre , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Vitamina D/análogos & derivados , Vitamina D/sangre , Deficiencia de Vitamina D/complicaciones
13.
Pharm Biol ; 54(2): 347-53, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25963228

RESUMEN

CONTEXT: Cryptoporus volvatus (Peck) Hubb grows wild in China, and its fruiting bodies have been used traditionally to treat asthma and bronchitis. OBJECTIVES: This study evaluates the anti-inflammatory effect of Cryptoporus polysaccharides (CP) extracted from fruiting bodies of C. volvatus on lipopolysaccharide (LPS)-induced pro-inflammatory factors and the signaling pathways involved in human alveolar epithelial cells. MATERIALS AND METHODS: To evaluate the effects of CP on LPS-induced pro-inflammatory factors, A549 cells were pre-incubated with CP 1, 10, and 100 µg/ml for 1 h and then stimulated with LPS 10 µg/ml for 24 h. The expression of pro-inflammatory factors monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), Toll-like receptor 2 (TLR2), and phosphorylation of ERK1/2, p38, and NF-κB p65 were measured by q-PCR, ELISA, and western blotting. RESULTS: CP decreased LPS-induced mRNA expression of MCP-1, TNF-α, and IL-1ß (IC50 = 83.3, 85.2, and 91.6 µg/ml, respectively) and their correspondent protein expression (IC50 = 88.6, 76.4, and 81.6 µg/ml, respectively). Investigation of potential mechanisms indicated that CP 100 µg/ml reduced LPS-induced expression of TLR2 mRNA (66.9%, p < 0.01) and protein (63.2%, p < 0.01) that was a result of the decreased pro-inflammatory factors. LPS induction increased the expression of TLR2 and the phosphorylation of p38 and ERK1/2, NF-kB p65 concomitantly. CP 100 µg/ml inhibited the LPS-induced phosphorylation of the signaling proteins (p < 0.05). CONCLUSIONS: This suggests that CP pretreatment down-regulates LPS-mediated inflammation in lung epithelial cells. This study further confirmed that CP is a potential anti-inflammatory drug for the treatment of airway inflammatory diseases.


Asunto(s)
Antiinflamatorios/farmacología , Coriolaceae/química , Citocinas/genética , Células Epiteliales/efectos de los fármacos , Polisacáridos Fúngicos/farmacología , Alveolos Pulmonares/efectos de los fármacos , Receptor Toll-Like 2/metabolismo , Antiinflamatorios/aislamiento & purificación , Western Blotting , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citocinas/inmunología , Relación Dosis-Respuesta a Droga , Células Epiteliales/inmunología , Polisacáridos Fúngicos/aislamiento & purificación , Humanos , Lipopolisacáridos/farmacología , Alveolos Pulmonares/citología , Alveolos Pulmonares/inmunología , Transducción de Señal , Factores de Tiempo
14.
J Photochem Photobiol B ; 153: 13-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26386623

RESUMEN

Systemic PDT (SPDT) approach is developed to treat a variety of hematological diseases, including cancers and blood-borne infections. We evaluated the efficacy of an SPDT method for treating leukemia using a Brown Norway myeloid leukemia (BNML) rat model with the LT12 cells engineered to express GFP. The survival times of animals receiving SPDT at 5 (early-SPDT) and 10 (mid-SPDT) days post-LT12 injection were prolonged by 2 days, the rats in the late-SPDT group (15 days) exhibited a 6-day increase in life span (p<0.05). The percentages of GFP-LT12 cells in the bone marrow of the late-SPDT rats decreased from 61.6% to 56.5% on day 17. Likewise, there was a decrease in the serum expression levels of IL-1ß, IL-10, TNF-α, and IFN-γ in the late-SPDT rats (p<0.05). Our findings indicate that SPDT could be an effective method for the treatment of leukemia, and that antitumor immunity may play a key role in this process.


Asunto(s)
Leucemia Mieloide Aguda/tratamiento farmacológico , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Línea Celular Tumoral , Citocinas/sangre , Modelos Animales de Enfermedad , Células HEK293 , Hematoporfirinas/uso terapéutico , Humanos , Láseres de Semiconductores , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Masculino , Ratas , Ratas Endogámicas BN , Trasplante Homólogo
15.
PLoS One ; 10(4): e0124941, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25919138

RESUMEN

Intrinsically disordered sequences within bacterial adhesins bind to E-strands in the ß-sheets of multiple FNI modules of fibronectin (FN) by anti-parallel ß-strand addition, also called tandem ß-zipper formation. The FUD segment of SfbI of Streptococcus pyogenes and Bbk32 segment of BBK32 of Borrelia burgdorferi, despite being imbedded in different adhesins from different bacteria, target the same 2-5,8-9 FNI modules, 2-5,8-9 FNI, in the N-terminal 70-kDa region (FN70K) of FN. To facilitate further comparisons, FUD, Bbk32, two other polypeptides based on SfbI that target 1-5 FNI (HADD) and 2-5 FNI (FRD), and mutant Bbk32 (ΔBbk32) were produced with fluorochromes placed just outside of the binding sequences. Unlabeled FUD competed ~ 1000-fold better for binding of labeled Bbk32 to FN than unlabeled Bbk32 competed for binding of labeled FUD to FN. Binding kinetics were determined by fluorescence polarization in a stopped-flow apparatus. On-rates for FUD, Bbk32, HADD, and FRD were similar, and all bound more rapidly to FN70K fragment than to full length FN. In stopped-flow displacement and size exclusion chromatographic assays, however, k off for FUD or HADD to FN70K or FN was considerably lower compared to k off of FRD or Bbk32. FUD and Bbk32 differ in the spacing between sequences that interact with 3FNI and 4FNI or with 5FNI and 8FNI. ΔBbk32, in which 2 residues were removed from Bbk32 to make the spacing more like FUD, had a k off intermediate between that of Bbk32 and FUD. These results indicate a "folding-after-binding" process after initial association of certain polypeptide sequences to FN that results in formation of a stable complex and is a function of number of FNI modules engaged by the polypeptide, spacing of engagement sites, and perhaps flexibility within the polypeptide-FN complex. We suggest that contributions of SfbI and BBK32 adhesins to bacterial pathogenicity may be determined in part by stability of adhesin-FN complexes.


Asunto(s)
Fibronectinas/química , Fibronectinas/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Unión Competitiva , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Fluorometría , Cinética , Ligandos , Datos de Secuencia Molecular , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Péptidos/química , Péptidos/metabolismo , Unión Proteica , Estabilidad Proteica , Estructura Secundaria de Proteína , Solubilidad
16.
Crit Rev Biochem Mol Biol ; 51(4): 213-27, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-27185500

RESUMEN

Fibronectin is a large vertebrate glycoprotein that is found in soluble and insoluble forms and involved in diverse processes. Protomeric fibronectin is a dimer of subunits, each of which comprises 29-31 modules - 12 type I, two type II and 15-17 type III. Plasma fibronectin is secreted by hepatocytes and circulates in a compact conformation before it binds to cell surfaces, converts to an extended conformation and is assembled into fibronectin fibrils. Here we review biophysical and structural studies that have shed light on how plasma fibronectin transitions from the compact to the extended conformation. The three types of modules each have a well-organized secondary and tertiary structure as defined by NMR and crystallography and have been likened to "beads on a string". There are flexible sequences in the N-terminal tail, between the fifth and sixth type I modules, between the first two and last two of the type III modules, and at the C-terminus. Several specific module-module interactions have been identified that likely maintain the compact quaternary structure of circulating fibronectin. The quaternary structure is perturbed in response to binding events, including binding of fibronectin to the surface of vertebrate cells for fibril assembly and to bacterial adhesins.


Asunto(s)
Fibronectinas/sangre , Fibronectinas/química , Animales , Fibronectinas/metabolismo , Humanos , Conformación Proteica
17.
J Biol Chem ; 290(8): 4866-4876, 2015 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-25525266

RESUMEN

SFS is a non-anchored protein of Streptococcus equi subspecies equi that causes upper respiratory infection in horses. SFS has been shown to bind to fibronectin (FN) and block interaction of FN with type I collagen. We have characterized interactions of a recombinant 60-mer polypeptide, R1R2, with FN. R1R2 contains two copies of collagen-like 19-residue repeats. Experiments utilizing various FN fragments and epitope-mapped anti-FN monoclonal antibodies located the binding site to (8-9)FNI modules of the gelatin-binding domain. Fluorescence polarization and competitive enzyme-linked assays demonstrated that R1R2 binds preferentially to compact dimeric FN rather than monomeric constructs containing (8-9)FNI or a large dimeric FN construct that is constitutively in an extended conformation. In contrast to bacterial peptides that bind (2-5)FNI in addition to (8-9)FNI, R1R2 did not cause conformational extension of FN as assessed by a conformationally sensitive antibody. Equilibrium and stopped-flow binding assays and size exclusion chromatography were compatible with a two-step binding reaction in which each of the repeats of R1R2 interacts with one of the subunits of dimeric FN, resulting in a stable complex with a slow koff. In addition to not binding to type I collagen, the R1R2·FN complex incorporated less efficiently into extracellular matrix than free FN. Thus, R1R2 binds to FN utilizing features of compact soluble FN and in doing so interferes with the organization of the extracellular matrix. A similar bivalent binding strategy may underlie the collagen-FN interaction.


Asunto(s)
Proteínas Bacterianas/química , Fibronectinas/química , Streptococcus equi/química , Proteínas Bacterianas/genética , Fibronectinas/genética , Estructura Terciaria de Proteína , Streptococcus equi/genética
18.
Artículo en Inglés | MEDLINE | ID: mdl-25467970

RESUMEN

In response to endothelial cell activation, arachidonic acid can be converted by cytochrome P450 (CYP) epoxygenases to epoxyeicosatrienoic acids (EETs), which have potent vasodilator and anti-inflammatory properties. In this study, we investigated the effects of exogenous EETs on cigarette smoke extract (CSE)-induced inflammation in human bronchial epithelial cells (NCI-H292). We found that CSE inhibited the expression of CYP2C8 and mildly stimulated the expression of epoxide hydrolase 2 (EPHX2) but did not change the expression of CYP2J2. Treatment with 11,12-EET or 14,15-EET attenuated the CSE-induced release of interleukin (IL)-8 by inhibiting the phosphorylation of p38 mitogen-activated protein kinases (MAPKs). Our results demonstrated that CSE may reduce the anti-inflammatory ability of epithelial cells themselves by lowering the EET level. EETs from pulmonary epithelial cells may play a critical protective role on epithelial cell injury.


Asunto(s)
Ácido 8,11,14-Eicosatrienoico/farmacología , Antiinflamatorios/farmacología , Bronquios/citología , Células Epiteliales/efectos de los fármacos , Interleucina-8/genética , Fumar/efectos adversos , Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Bronquios/efectos de los fármacos , Línea Celular , Citocromo P-450 CYP2J2 , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Células Epiteliales/citología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-8/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Vasodilatadores/farmacología
19.
J Biol Chem ; 289(32): 22490-9, 2014 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-24962582

RESUMEN

BBK32 is a fibronectin (FN)-binding protein expressed on the cell surface of Borrelia burgdorferi, the causative agent of Lyme disease. There is conflicting information about where and how BBK32 interacts with FN. We have characterized interactions of a recombinant 86-mer polypeptide, "Bbk32," comprising the unstructured FN-binding region of BBK32. Competitive enzyme-linked assays utilizing various FN fragments and epitope-mapped anti-FN monoclonal antibodies showed that Bbk32 binding involves both the fibrin-binding and the gelatin-binding domains of the 70-kDa N-terminal region (FN70K). Crystallographic and NMR analyses of smaller Bbk32 peptides complexed, respectively, with (2-3)FNI and (8-9)FNI, demonstrated that binding occurs by ß-strand addition. Isothermal titration calorimetry indicated that Bbk32 binds to isolated FN70K more tightly than to intact FN. In a competitive enzyme-linked binding assay, complex formation with Bbk32 enhanced binding of FN with mAbIII-10 to the (10)FNIII module. Thus, Bbk32 binds to multiple FN type 1 modules of the FN70K region by a tandem ß-zipper mechanism, and in doing so increases accessibility of FNIII modules that interact with other ligands. The similarity in the FN-binding mechanism of BBK32 and previously studied streptococcal proteins suggests that the binding and associated conformational change of FN play a role in infection.


Asunto(s)
Proteínas Bacterianas/metabolismo , Borrelia burgdorferi/metabolismo , Fibronectinas/química , Fibronectinas/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Borrelia burgdorferi/genética , Borrelia burgdorferi/patogenicidad , Cristalografía por Rayos X , Epítopos/química , Epítopos/metabolismo , Fibronectinas/inmunología , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Unión Proteica , Conformación Proteica , Dominios y Motivos de Interacción de Proteínas
20.
Lasers Med Sci ; 29(3): 1043-50, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24158722

RESUMEN

Asthma is a complex chronic inflammatory disease of the airways that involves the activation of many inflammatory and other types of cells. We investigated the effect of low-level laser therapy (LLLT) on allergic asthma in rats and compared its effect with that of the glucocorticoid budesonide. Asthma was induced by challenge and repeated exposure to ovalbumin. Asthmatic rats were then treated with LLLT or budesonide suspension. LLLT at 8 J/cm(2) once daily for 21 days could relieve pathological damage and airway inflammation in asthmatic rats. LLLT could decrease the total numbers of cells and eosinophils in bronchoalveolar lavage fluid. LLLT could reduce levels of IL-4 and increase IFN-γ levels in bronchoalveolar lavage fluid and serum, meanwhile reduce serum IgE levels. Flow cytometry assay showed that LLLT can regulate the Th1/Th2 imbalance of asthmatic rats. LLLT had a similar effect to that of budesonide. These findings suggest that the mechanism of LLLT treatment of asthma is by adjustment of Th1/Th2 imbalance. Thus, LLLT could take over some of the effects of budesonide for the treatment of asthma, thereby reducing some of the side effects of budesonide.


Asunto(s)
Asma/radioterapia , Láseres de Semiconductores/uso terapéutico , Terapia por Luz de Baja Intensidad , Animales , Asma/sangre , Asma/inmunología , Inmunoglobulina E/sangre , Interferón gamma/sangre , Interleucina-4/sangre , Masculino , Ratas Wistar , Células TH1/inmunología , Células Th2/inmunología , Resultado del Tratamiento
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