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1.
J Acoust Soc Am ; 153(4): 1960, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37092918

RESUMO

This paper describes a room response equalization technique based on an underdetermined multichannel inverse filtering (UMIF) and linearly constrained minimum variance (LCMV) approach. Not limited to the local control at the neighborhood of the measured control points, the proposed UMIF-LCMV system is capable of widening the effective equalization area of the reproduced sound field, with a large number of interpolated control points. Specifically, a constrained optimization problem is formulated to minimize the matching error at the interpolated control points while seeking precise matching at the measured control points. In practical implementation, only the frequency responses (FRs) associated with a limited number of control points need to be measured, whereas the FRs for the interpolated points are established by using a plane wave decomposition-based sensor interpolation technique. A two-stage procedure is developed to trim down plane wave components by using the least absolute shrinkage and selection operator (LASSO) algorithm and to obtain the complex amplitudes of the principal components. Simulations and objective and subjective experiments are conducted for a system comprising a linear loudspeaker array and a linear microphone array. The results have confirmed the efficacy of the proposed system in widening the effective listening area with only limited discrete measurements.

2.
Wilderness Environ Med ; 33(3): 304-310, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35843857

RESUMO

INTRODUCTION: This study compared the casualties and types of rescues conducted on the main climbing route (MCR) and accessory climbing routes (ACRs) in Yushan National Park (YSNP) between 2008 and 2019. METHODS: We collected the following information for all documented mountain rescue operations conducted on the MCRs and ACRs in YSNP between 2008 and 2019: accident location, casualty type, victim number, and type of rescue. The victims were categorized as to injury, illness, mortality, or no medical problem (NMP) groups according to their condition at the time of rescue. RESULTS: Two-hundred forty-four rescue operations involving 329 victims were conducted during the 12-y study period. Among them, 105 (32%) did not require medical treatment, 102 (31%) were injured, 82 (25%) were ill, and 40 (12%) were deceased. Of the 82 individuals with illness, 69 (84%) had acute altitude sickness. The accident and mortality rates on the ACRs were significantly higher than those on the MCR (P<0.001; χ2). The ACR incidents involved significantly higher percentages of helicopter-based rescues and victims in the NMP group (P<0.001). CONCLUSIONS: Acute altitude sickness accounted for most of the rescues. ACRs had higher injury and mortality rates and required more helicopter-based rescues for patients who did not have medical problems. This study may serve as a reference to reduce casualties and overuse of helicopters by educating tourists on the appropriate use of maps and the evaluation of trails in relation to weather conditions.


Assuntos
Resgate Aéreo , Doença da Altitude , Serviços Médicos de Emergência , Aeronaves , Doença da Altitude/epidemiologia , Doença da Altitude/terapia , Humanos , Parques Recreativos , Trabalho de Resgate , Estudos Retrospectivos
3.
Cells ; 9(9)2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32911838

RESUMO

Hepatitis B is the most prevalent viral hepatitis worldwide, affecting approximately one-third of the world's population. Among HBV factors, the surface protein is the most sensitive biomarker for viral infection, given that it is expressed at high levels in all viral infection phases. The large HBV surface protein (LHBs) contains the integral pre-S1 domain, which binds to the HBV receptor sodium taurocholate co transporting polypeptide on the hepatocyte to facilitate viral entry. The accumulation of viral LHBs and its prevalent pre-S mutants in chronic HBV carriers triggers a sustained endoplasmic reticulum (ER) overload response, leading to ER stress-mediated cell proliferation, metabolic switching and genomic instability, which are associated with pro-oncogenic effects. Ground glass hepatocytes identified in HBV-related hepatocellular carcinoma (HCC) patients harbor pre-S deletion variants that largely accumulate in the ER lumen due to mutation-induced protein misfolding and are associated with increased risks of cancer recurrence and metastasis. Moreover, in contrast to the major HBs, which is decreased in tumors to a greater extent than it is in peritumorous regions, LHBs is continuously expressed during tumorigenesis, indicating that LHBs serves as a promising biomarker for HCC in people with CHB. Continuing efforts to delineate the molecular mechanisms by which LHBs regulates pathological changes in CHB patients are important for establishing a correlation between LHBs biomarkers and HCC development.


Assuntos
Carcinoma Hepatocelular/virologia , Vírus da Hepatite B/patogenicidade , Neoplasias Hepáticas/virologia , Carcinoma Hepatocelular/patologia , Estresse do Retículo Endoplasmático , Vírus da Hepatite B/metabolismo , Humanos , Neoplasias Hepáticas/patologia
4.
Small ; 15(30): e1901908, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31165563

RESUMO

MoS2 quantum dots (QDs)-based white-light-emitting diodes (QD-WLEDs) are designed, fabricated, and demonstrated. The highly luminescent, histidine-doped MoS2 QDs synthesized by microwave induced fragmentation of 2D MoS2 nanoflakes possess a wide distribution of available electronic states as inferred from the pronounced excitation-wavelength-dependent emission properties. Notably, the histidine-doped MoS2 QDs show a very strong emission intensity, which exceeds seven times of magnitude larger than that of pristine MoS2 QDs. The strongly enhanced emission is mainly attributed to nitrogen acceptor bound excitons and passivation of defects by histidine-doping, which can enhance the radiative recombination drastically. The enabled electroluminescence (EL) spectra of the QD-WLEDs with the main peak around 500 nm are found to be consistent with the photoluminescence spectra of the histidine-doped MoS2 QDs. The enhanced intensity of EL spectra with the current increase shows the stability of histidine-doped MoS2 based QD-WLEDs. The typical EL spectrum of the novel QD-WLEDs has a Commission Internationale de l'Eclairage chromaticity coordinate of (0.30, 0.36) exhibiting an intrinsic broadband white-light emission. The unprecedented and low-toxicity QD-WLEDs based on a single light-emitting material can serve as an excellent alternative for using transition metal dichalcogenides QDs as next generation optoelectronic devices.

5.
J Food Drug Anal ; 27(2): 483-493, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30987719

RESUMO

Oral cancer with high incidence rates is occurring in many countries including in India, Pakistan, Bangladesh, Sri Lanka and Taiwan. Smoking, alcoholism, and betel nut chewing are considered to be the main risk factors for oral cancer. Further, deaths from oral cancer have increased year by year. Although several oral cancer-associated biomarkers have been reported, very few useful biomarkers have been applied for early diagnosis. Therefore, the investigation of oral cancer-specific biomarkers is urgently needed. We previously investigated N-glycomes of oral cancer cells and patient plasma. We found that both mRNA levels of FUT8 and core-fucosylated glycoproteins increase in cases of oral cancer relative to normal cases. In this study we aim to discover novel core-fucosylated glycoprotein biomarkers for oral cancer diagnosis with glycoproteomic approaches. First, forty plasma samples obtained from the Human Bioinformation Bank of NCKUH were subjected to AAL (Aleuria aurantia lectin) affinity chromatography. Core-fucosylated proteins were collected and applied for LC-MS/MS followed by electrophoresis. Fourteen proteins were identified, and expression levels of proteins in plasma were verified by western blot. Expression levels of some glycoproteins were elevated in the oral cancer group, including ceruloplasmin, haptoglobin, and leucin-rich alpha-2-glycoprotein 1 (LRG1). However, levels of some glycoproteins decreased in the cancer group, including apolipoprotein A-I (apo A-I) and apolipoprotein A-IV (apo A-IV). Via ELISA analysis, we found that apo A-IV and apo A-IV/total protein ratios were decreased in plasma accompanied with cancer stages. The LRG1/total protein ratio was found to increase while plasma levels of LRG1 were not found to differ between the oral cancer plasma and normal groups. An ROC curve analysis reveals strong diagnosis performance when combining apo A-IV levels and LRG1/total protein ratios. Taken together, apo A-IV and LRG1, given their strong performance in detecting oral cancer, can serve as useful biomarkers and may be used as a useful tool for oral cancer screening and early diagnosis.


Assuntos
Biomarcadores Tumorais/sangue , Glicoproteínas/sangue , Neoplasias Bucais/sangue , Proteômica , Adulto , Biologia Computacional , Eletroforese em Gel de Poliacrilamida , Feminino , Humanos , Masculino , Espectrometria de Massas , Neoplasias Bucais/diagnóstico , Curva ROC
6.
iScience ; 11: 305-317, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30639852

RESUMO

Dynamic processes such as fusion, fission, and trafficking are important in the regulation of cellular organelles, with an abundant literature focused on mitochondria. Mitochondrial dynamics not only help shape its network within cells but also are involved in the modulation of respiration and integrity. Disruptions of mitochondrial dynamics are associated with neurodegenerative disorders. Although proteins that directly bind mitochondria to promote membrane fusion/fission have been studied intensively, machineries that regulate dynamic mitochondrial processes remain to be explored. We have identified an interaction between the mitochondrial fission GTPase Dnm1/DRP1 and the actin-regulatory protein Srv2/CAP at mitochondria. Deletion of Srv2 causes elongated-hyperfused mitochondria and reduces the reserved respiration capacity in yeast cells. Our results further demonstrate that the irregular network morphology in Δsrv2 cells derives from disrupted actin assembly at mitochondria. We suggest that Srv2 functions as a pro-fission factor in shaping mitochondrial dynamics and regulating activity through its actin-regulatory effects.

7.
Immunol Cell Biol ; 95(4): 372-379, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27808085

RESUMO

The leukocyte adhesion cascade involves multiple events that efficiently localize circulating leukocytes into the injured sites to mediate inflammatory responses. From rolling to firm adhesion, the interactions between adhesion molecules have pivotal roles in increasing the avidity of leukocytes to endothelial cells. Thrombomodulin (TM), an essential anticoagulant protein in the vasculature, is also expressed on leukocytes. We previously demonstrated that Lewisy (Ley), a specific ligand of TM, is upregulated in inflamed endothelium and is involved in leukocyte adhesion. The current study aimed to investigate whether leukocyte-expressed TM promotes cell adhesion by interacting with Ley. Using human monocytic THP-1 cells as an in vitro cell model, we showed that TM increases THP-1 cell adhesion to inflamed endothelium as well as to Ley-immobilized surface. When THP-1 adhered to activated endothelium and Ley-immobilized surface, the TM distribution became polarized. Addition of soluble Ley to a suspension of THP-1 cells with TM expression triggered an increase in the level of phosphorylated p38 mitogen-activated protein kinase (MAPK), which enabled THP-1 to adhere firmly to intercellular adhesion molecule (ICAM)-1 by activating ß2 integrins. In vivo, macrophage infiltration and neointima formation following arterial ligation-induced vascular injury were higher in wild-type TM (TMflox/flox) than in myeloid-specific TM-deficient (LysMcre/TMflox/flox) mice. Taken together, these results suggest a novel function for TM as an adhesion molecule in monocytes, where it enhances cell adhesion by binding Ley, leading to ß2 integrin activation via p38 MAPK.


Assuntos
Células Endoteliais/imunologia , Inflamação/imunologia , Monócitos/imunologia , Neointima/imunologia , Trombomodulina/metabolismo , Animais , Antígenos CD18/metabolismo , Adesão Celular , Modelos Animais de Doenças , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Antígenos do Grupo Sanguíneo de Lewis/metabolismo , Ligantes , Camundongos , Camundongos Knockout , RNA Interferente Pequeno/genética , Transdução de Sinais , Células THP-1 , Trombomodulina/agonistas , Trombomodulina/genética , Regulação para Cima , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
8.
PLoS One ; 10(6): e0130389, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26076445

RESUMO

Molecules derived from cinnamon have demonstrated diverse pharmacological activities against infectious pathogens, diabetes and inflammatory diseases. This study aims to evaluate the effect of the cinnamon-derived molecule IND02 on the adhesion of leukocytes to host cells. The anti-inflammatory ability of IND02, a pentameric procyanidin type A polyphenol polymer isolated from cinnamon alcohol extract, was examined. Pretreatment with IND02 significantly reduced the attachment of THP-1 cells or neutrophils to TNF-α-activated HUVECs or E-selectin/ICAM-1, respectively. IND02 also reduced the binding of E-, L- and P-selectins with sialosides. Furthermore, IND02 could agglutinate human red blood cells (RBC), and the agglutination could be disrupted by sialylated glycoprotein. Our findings demonstrate that IND02, a cinnamon-derived compound, can interact with sialosides and block the binding of selectins and leukocytes with sialic acids.


Assuntos
Adesão Celular/efeitos dos fármacos , Cinnamomum zeylanicum/metabolismo , Agregação Eritrocítica/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Neutrófilos/metabolismo , Proantocianidinas/farmacologia , Aglutinação/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Linhagem Celular Tumoral , Medicamentos de Ervas Chinesas/farmacologia , Selectina E/metabolismo , Endotélio Vascular/metabolismo , Eritrócitos/efeitos dos fármacos , Humanos , Inflamação/tratamento farmacológico , Molécula 1 de Adesão Intercelular/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Orthomyxoviridae/metabolismo , Ligação Proteica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
9.
Yao Xue Xue Bao ; 50(2): 203-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25975029

RESUMO

A novel citrinin derivative, penicitrinol L (1), along with two known analogues, penidicitrinin B (2) and pennicitrinone A (3) were isolated from the marine-source fungus Penicillium citrinum. The structure of the new compound was elucidated by spectroscopic methods including one and two-dimensional NMR as well as high-resolution mass spectrometric analysis. Furthermore, compound 1 showed modest cytotoxic activity against HL-60 cell line and compound 3 showed weak cytotoxic activity against A375 cell line.


Assuntos
Citrinina/análogos & derivados , Penicillium/química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Citrinina/química , Citrinina/isolamento & purificação , Células HL-60 , Humanos , Espectroscopia de Ressonância Magnética
10.
PLoS One ; 10(3): e0120162, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25799278

RESUMO

Aberrant glycosylation changes normal cellular functions and represents a specific hallmark of cancer. Lewisy (Ley) carbohydrate upregulation has been reported in a variety of cancers, including oral squamous cell carcinoma (OSCC). A high level of Ley expression is related to poor prognosis of patients with oral cancer. However, it is unclear how Ley mediates oral cancer progression. In this study, the role of Ley in OSCC was explored. Our data showed that Ley was upregulated in HSC-3 and OC-2 OSCC cell lines. Particularly, glycosylation of epidermal growth factor receptor (EGFR) with Ley was found in OC-2 cells, and this modification was absent upon inhibition of Ley synthesis. The absence of Ley glycosylation of EGFR weakened phosphorylation of AKT and ERK in response to epidermal growth factor (EGF). Additionally, EGF-triggered cell migration was reduced, but cell proliferation was not affected. Ley modification stabilized EGFR upon ligand activation. Conversely, absence of Ley glycosylation accelerated EGFR degradation. In summary, these results indicate that increased expression of Ley in OSCC cells is able to promote cell migration by modifying EGFR which in turn stabilizes EGFR expression and downstream signaling. Targeting Ley on EGFR could have a potential therapeutic effect on oral cancer.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Movimento Celular , Receptores ErbB/metabolismo , Antígenos do Grupo Sanguíneo de Lewis/metabolismo , Neoplasias Bucais/metabolismo , Processamento de Proteína Pós-Traducional , Linhagem Celular Tumoral , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glicosilação , Humanos , Queratinócitos/metabolismo , Queratinócitos/fisiologia , Antígenos do Grupo Sanguíneo de Lewis/genética , Masculino , Proteínas Proto-Oncogênicas c-akt/metabolismo
11.
J Invest Dermatol ; 135(6): 1668-1675, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25651160

RESUMO

Keratinocyte-expressed thrombomodulin (TM) and the released soluble TM (sTM) have been demonstrated to promote wound healing. However, the effects of high glucose on TM expression in keratinocytes and the role of TM in diabetic ulcer remain unclear. In this study, we demonstrated that expressions of TM and Toll-like receptor 4 (TLR4) were both downregulated in high-glucose cultured human keratinocytes and in skin keratinocytes of diabetic patients. In addition, the wound-triggered upregulation of TM and sTM production was abolished in both high-glucose cultured human keratinocytes and streptozotocin-induced diabetic mouse skin. Furthermore, supplementation of recombinant sTM could increase TLR4 expression and promote cutaneous wound healing in both high-glucose cultured human keratinocytes and diabetic mice. However, in Tlr4-deleted mice, which exhibited delayed wound healing, the therapeutic benefit of recombinant sTM was abrogated. Moreover, our results showed that tumor necrosis factor-α (TNF-α) expression in keratinocytes was dose-dependently upregulated by glucose, and TNF-α treatment downregulated the expression of TM and TLR4. Taken together, high-glucose environment reduces the expression of TM and TLR4 in keratinocytes possibly through the action of TNF-α, and recombinant sTM can increase the TLR4 expression and promote wound healing under diabetic condition.


Assuntos
Complicações do Diabetes/metabolismo , Diabetes Mellitus Experimental/metabolismo , Trombomodulina/fisiologia , Receptor 4 Toll-Like/metabolismo , Cicatrização , Animais , Linhagem Celular Tumoral , Deleção de Genes , Regulação da Expressão Gênica , Glucose/química , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Recombinantes/metabolismo , Pele/metabolismo , Estreptozocina/química , Fator de Necrose Tumoral alfa/metabolismo
12.
Hu Li Za Zhi ; 62(1): 50-7, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-25631184

RESUMO

BACKGROUND: Obesity is a worldwide epidemic that threats the health and body image of those who suffer from this condition. While bariatric surgery has been shown to effectively assist patients to achieve weight loss goals and to improve body image, related research on this intervention is lacking in Taiwan. PURPOSE: The purpose of this research is to investigate the effect of bariatric surgery on body image in obese patients. METHODS: This study used a longitudinal design. Data was collected from 2 hospitals located in northern and southern Taiwan. A total of 56 obese patients who had undergone bariatric surgery enrolled as participants, and the completion rate was 93.3%. Participants responded to a validated body image questionnaire immediately prior to and 3 months after bariatric surgery, with data used to assess the effects of the surgery. SPSS 20.0 software for windows was used for data analysis. RESULTS: Participant scores for body image were low on the questionnaire administered prior to surgery, with a significant negative correlation identified between body mass index (BMI) and the value of appearance (r = -.36, p < .01). After bariatric surgery, the average EWL was 42.08%, which effectively achieved expected weight loss goals. Variables including overall body image, appearance evaluation, orientation, and body satisfaction of participants were significantly improved. Only the variable of muscle tension did not improve significantly. Postoperative body image did not correlate with either BMI or EWL. CONCLUSIONS: Three months after the bariatric surgery, the body image, appearance evaluation, and physical appearance satisfaction of participants had significantly improved. However, there was no improvement in muscle tension scores. In order to improve the post-surgery body image of patients, we recommend that healthcare workers provide patients with proper expectations of bariatric surgery and teach patients appropriate muscle-tension exercises. This paper reports the relation between bariatric surgery and body image. The results provide evidence for clinical and future research in this field.


Assuntos
Cirurgia Bariátrica , Imagem Corporal , Obesidade/cirurgia , Adulto , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Redução de Peso
13.
Arterioscler Thromb Vasc Biol ; 33(10): 2366-73, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23950139

RESUMO

OBJECTIVE: The N-terminal lectin-like domain (domain 1 [D1]) of thrombomodulin (TM) is known to have an anti-inflammatory function. We previously showed that recombinant TM domain 1 (rTMD1) interacts with a carbohydrate molecule, Lewis Y (Le(y)), which is found to be expressed on adhesion molecules and involved in cell adhesion. Here, we tested the effect of rTMD1/Le(y) interaction on leukocyte recruitment in inflammation. APPROACH AND RESULTS: The expression of Le(y) on the surface of human umbilical vein endothelial cells was increased by tumor necrosis factor-α stimulation. Direct binding of rTMD1 to Le(y) on the cell surface was observed. rTMD1 inhibited Le(y)-mediated leukocyte adhesion on the Le(y)-immobilized flow chamber and activated endothelium under a shear flow. The following leukocyte transmigration to endothelium was also reduced by rTMD1 through binding Le(y). In vivo, treatment of rTMD1 reduced leukocyte recruitment to the inflammatory sites in carotid ligation injury and thioglycollate-induced peritonitis. rTMD1 administration in apolipoprotein E-deficient mice effectively suppressed atherosclerotic plaque formation and macrophage infiltration in atherosclerotic lesions. Increased Le(y) expression, as well as administered rTMD1, was observed in inflamed vessels. CONCLUSIONS: rTMD1 suppresses vascular inflammation by inhibiting leukocyte recruitment to endothelium through attenuating Le(y)-mediated adhesion and further protects against atherosclerosis progression. The present study provides a mechanism showing that rTMD1 can inhibit inflammation by binding to its carbohydrate ligand Le(y).


Assuntos
Anti-Inflamatórios/administração & dosagem , Aterosclerose/prevenção & controle , Quimiotaxia de Leucócito/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Antígenos do Grupo Sanguíneo de Lewis/metabolismo , Neutrófilos/efeitos dos fármacos , Trombomodulina/administração & dosagem , Vasculite/prevenção & controle , Animais , Anti-Inflamatórios/metabolismo , Apolipoproteínas E/deficiência , Apolipoproteínas E/genética , Aterosclerose/imunologia , Aterosclerose/metabolismo , Aterosclerose/patologia , Lesões das Artérias Carótidas/imunologia , Lesões das Artérias Carótidas/metabolismo , Lesões das Artérias Carótidas/patologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Técnicas de Cocultura , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Células Endoteliais/imunologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/imunologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Antígenos do Grupo Sanguíneo de Lewis/imunologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/imunologia , Neutrófilos/metabolismo , Placa Aterosclerótica , Estrutura Terciária de Proteína , Proteínas Recombinantes/administração & dosagem , Trombomodulina/metabolismo , Migração Transendotelial e Transepitelial/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Vasculite/imunologia , Vasculite/metabolismo , Vasculite/patologia
14.
J Invest Dermatol ; 133(6): 1638-45, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23321922

RESUMO

The membrane glycoprotein thrombomodulin (TM) has been implicated in keratinocyte differentiation and wound healing, but its specific function remains undetermined. The epidermis-specific TM knockout mice were generated to investigate the function of TM in these biological processes. Primary cultured keratinocytes obtained from TM(lox/lox); K5-Cre mice, in which TM expression was abrogated, underwent abnormal differentiation in response to calcium induction. Poor epidermal differentiation, as evidenced by downregulation of the terminal differentiation markers loricrin and filaggrin, was observed in TM(lox/lox); K5-Cre mice. Silencing TM expression in human epithelial cells impaired calcium-induced extracellular signal-regulated kinase pathway activation and subsequent keratinocyte differentiation. Compared with wild-type mice, the cell spreading area and wound closure rate were lower in keratinocytes from TM(lox/lox); K5-Cre mice. In addition, the lower density of neovascularization and smaller area of hyperproliferative epithelium contributed to slower wound healing in TM(lox/lox); K5-Cre mice than in wild-type mice. Local administration of recombinant TM (rTM) accelerated healing rates in the TM-null skin. These data suggest that TM has a critical role in skin differentiation and wound healing. Furthermore, rTM may hold therapeutic potential for the treatment of nonhealing chronic wounds.


Assuntos
Queratinócitos/citologia , Queratinócitos/fisiologia , Trombomodulina/genética , Trombomodulina/metabolismo , Cicatrização/fisiologia , Animais , Cálcio/metabolismo , Diferenciação Celular/fisiologia , Linhagem Celular , Movimento Celular/fisiologia , Células Epidérmicas , Epiderme/fisiologia , Proteínas Filagrinas , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Knockout , Neovascularização Fisiológica/fisiologia , Fosforilação/fisiologia , Cultura Primária de Células
15.
Am J Pathol ; 176(6): 3050-61, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20395446

RESUMO

Podocalyxin was initially identified in glomerular podocytes to critically maintain the structural and functional integrity of the glomerular ultrafiltrative apparatus. Lately, it has emerged as a malignant marker in tumors arising from a variety of tissue origins. By immunohistochemistry, we identified that 9.6% of renal cell carcinoma patients overexpress this protein. This subset of patients had significantly shorter disease-specific and overall survivals, and, importantly, we established podocalyxin overexpression as an independent prognostic factor for latent distant metastasis with multivariate analysis. Podocalyxin down-regulation by small interfering RNA led to defective migration in model renal tubular cells, which was corrected by re-expression of podocalyxin. The activity of the small GTPase Rac1, a well-characterized modulator of cell migration, was diminished by podocalyxin knock-down. Conversely, podocalyxin overexpression in human embryonic kidney cells up-regulated Rac1 activity, which depended on a complex formed by podocalyxin, ERM-binding phosphoprotein 50, ezrin, and ARHGEF7, a Rac1 activator. Therefore, podocalyxin can serve as a biomarker to identify renal cell carcinoma patients with higher metastatic potential for more aggressive intervention at earlier clinical stages.


Assuntos
Carcinoma de Células Renais/patologia , Proteínas do Citoesqueleto/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Complexos Multiproteicos/metabolismo , Fosfoproteínas/metabolismo , Sialoglicoproteínas/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Adulto , Idoso , Animais , Carcinoma de Células Renais/metabolismo , Adesão Celular/fisiologia , Linhagem Celular , Movimento Celular/fisiologia , Proteínas do Citoesqueleto/genética , Cães , Ativação Enzimática , Feminino , Técnicas de Silenciamento de Genes , Fatores de Troca do Nucleotídeo Guanina/genética , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Fosfoproteínas/genética , Fatores de Troca de Nucleotídeo Guanina Rho , Sialoglicoproteínas/genética , Trocadores de Sódio-Hidrogênio/genética , Proteínas rac1 de Ligação ao GTP/genética
16.
Circ Res ; 104(6): 733-41, 2009 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-19197075

RESUMO

Vascular calcification is a major risk factor for cardiovascular morbidity and mortality. To develop appropriate prevention and/or therapeutic strategies for vascular calcification, it is important to understand the origins of the cells that participate in this process. In this report, we used the SM22-Cre recombinase and Rosa26-LacZ alleles to genetically trace cells derived from smooth muscle. We found that smooth muscle cells (SMCs) gave rise to osteochondrogenic precursor- and chondrocyte-like cells in calcified blood vessels of matrix Gla protein deficient (MGP(-/-)) mice. This lineage reprogramming of SMCs occurred before calcium deposition and was associated with an early onset of Runx2/Cbfa1 expression and the downregulation of myocardin and Msx2. There was no change in the constitutive expression of Sox9 or bone morphogenetic protein 2. Osterix, Wnt3a, and Wnt7a mRNAs were not detected in either calcified MGP(-/-) or noncalcified wild-type (MGP(+/+)) vessels. Finally, mechanistic studies in vitro suggest that Erk signaling might be required for SMC transdifferentiation under calcifying conditions. These results provide strong support for the hypothesis that adult SMCs can transdifferentiate and that SMC transdifferentiation is an important process driving vascular calcification and the appearance of skeletal elements in calcified vascular lesions.


Assuntos
Artérias/metabolismo , Calcinose/metabolismo , Condrócitos/metabolismo , Miócitos de Músculo Liso/metabolismo , Células-Tronco/metabolismo , Doenças Vasculares/metabolismo , Animais , Artérias/patologia , Proteína Morfogenética Óssea 2/genética , Proteína Morfogenética Óssea 2/metabolismo , Calcinose/genética , Calcinose/patologia , Desdiferenciação Celular/genética , Condrócitos/patologia , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação para Baixo/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Knockout , Camundongos Mutantes , Miócitos de Músculo Liso/patologia , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Fator de Transcrição Sp7 , Células-Tronco/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Doenças Vasculares/genética , Doenças Vasculares/patologia , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteína Wnt3 , Proteína Wnt3A
17.
Mol Biol Cell ; 18(5): 1710-22, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17332505

RESUMO

Podocalyxin/Gp135 was recently demonstrated to participate in the formation of a preapical complex to set up initial polarity in MDCK cells, a function presumably depending on the apical targeting of Gp135. We show that correct apical sorting of Gp135 depends on a bipartite signal composed of an extracellular O-glycosylation-rich region and the intracellular PDZ domain-binding motif. The function of this PDZ-binding motif could be substituted with a fusion construct of Gp135 with Ezrin-binding phosphoprotein 50 (EBP50). In accordance with this observation, EBP50 binds to newly synthesized Gp135 at the Golgi apparatus and facilitates oligomerization and sorting of Gp135 into a clustering complex. A defective connection between Gp135 and EBP50 or EBP50 knockdown results in a delayed exit from the detergent-resistant microdomain, failure of oligomerization, and basolateral missorting of Gp135. Furthermore, the basolaterally missorted EBP50-binding defective mutant of Gp135 was rapidly retrieved via a PKC-dependent mechanism. According to these findings, we propose a model by which a highly negative charged transmembrane protein could be packed into an apical sorting platform with the aid of its cytoplasmic partner EBP50.


Assuntos
Sialoglicoproteínas/metabolismo , Motivos de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/genética , Polaridade Celular , Células Cultivadas , Proteínas do Citoesqueleto/metabolismo , Cães , Endocitose , Glicosilação , Microdomínios da Membrana/metabolismo , Modelos Biológicos , Mutação , Proteína Quinase C/metabolismo , Sinais Direcionadores de Proteínas/genética , Estrutura Terciária de Proteína , RNA Interferente Pequeno/genética , Sialoglicoproteínas/química , Sialoglicoproteínas/genética , Transdução de Sinais
18.
Histochem Cell Biol ; 127(4): 399-414, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17180683

RESUMO

Podocalyxin (PC) was initially identified as a major sialoprotein on the apical surface of glomerular podocytes to perform the filtration barrier function. Later, it was reported to be expressed in endothelial cells, megakaryotes/platelets, and hemangioblasts, the common progenitor cells of the hematopoietic and endothelial cells. Recently, increasing numbers of reports have indicated that PC is not merely a molecule restricted at renal glomerulus, angiogenic or hematopoietic system. To further elucidate the expression pattern and address the possible physiological role of PC in adult mammals, we conducted an extensive study by immunohistochemistry and immunofluorescence staining on various tissues of healthy adult beagle dogs. By combinatory usage of two different anti-podocalyxin antibodies recognizing distinct epitopes in PC, we have demonstrated that (1) PC is expressed in renal tubules, mesothelium, myocardium, striated muscles in tongue, esophagus and extraocular region, myoepithelial cells in esophagus and salivary glands, neurons, and ependyma, etc.; (2) there are at least three forms of PC proteins, depending upon the accessibility of two different PC antibodies, expressed in different organs/systems; and (3) a particular form of PC is distributed in a vesicle-like compartment in certain organs/systems, such as the central nervous system.


Assuntos
Biomarcadores/análise , Glomérulos Renais/química , Podócitos/química , Sialoglicoproteínas/análise , Animais , Western Blotting , Células da Medula Óssea/química , Linhagem Celular , Linhagem Celular Tumoral , Sistema Digestório/química , Cães , Sistema Endócrino/química , Olho/química , Feminino , Genitália Feminina/química , Genitália Masculina/química , Humanos , Sistema Imunitário/química , Imuno-Histoquímica , Glomérulos Renais/citologia , Masculino , Miocárdio/química , Sistema Nervoso/química , Podócitos/citologia , Sistema Urinário/química
19.
J Am Soc Nephrol ; 16(6): 1612-22, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15814834

RESUMO

GP135 is an apical membrane protein expressed in polarized MDCK epithelial cells. When cultured in three-dimensional collagen gel, MDCK cells form branching tubules in response to hepatocyte growth factor stimulation in a manner that simulates the embryonic renal development. During this process, GP135 displays transient loss of membranous localization but reappears at the cell surface when nascent lumen emerges from the developing tubules. Despite being used for decades as the canonical hallmark of apical surface, the molecular identity and the significance of the dynamic expression of GP135 during the tubulogenic process remain elusive. For exploring the function of GP135, the full-length cDNA encoding GP135 was obtained. Sequence alignments and features analysis confirm GP135 as a canine homolog of podocalyxin, confirming the finding of an earlier independent study. Immunohistochemical assays on canine kidney sections identified both glomerular and tubular distribution of GP135 along the nephron. Mutant MDCK cells expressing siRNA targeted at two regions of GP135 show defects in hepatocyte growth factor-induced tubulogenesis. Re-expression of full-length and an O-linked glycosylation abbreviated construct of GP135 could recapitulate the tubulogenesis process lacking in siRNA knockdown cells; however, a deletion construct devoid of the cytoplasmic domain failed to rescue the phenotype. In summary, the data identify the MDCK apical domain marker GP135 as a tubular form of podocalyxin and provide evidence for its importance in renal tubulogenesis.


Assuntos
Túbulos Renais/fisiologia , Sialoglicoproteínas/fisiologia , Animais , Linhagem Celular , Clonagem Molecular , DNA Complementar , Cães , Células Epiteliais , Glicoproteínas de Membrana/fisiologia , Camundongos
20.
FEBS Lett ; 577(1-2): 67-74, 2004 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-15527763

RESUMO

Solamargine (SM), isolated from Solanum incanum herb, displayed a superior cytotoxicity in four human lung cancer cell lines. The half-inhibitory concentrations (IC50), of the cell viability assay for H441, H520, H661 and H69 cells were 3, 6.7, 7.2 and 5.8 microM, respectively. SM-induced apoptosis of these cells by PS externalization in a dose-dependent manner and increased sub-G1 fraction were observed. Quenching of the expression of tumor necrosis factor receptors (TNFRs) during the progress of human lung carcinogenesis has been previously reported. SM may induce cell apoptosis via modulating the expression of TNFRs and their subsequent TRADD/FADD signal cascades. Subsequently, SM treatment increased the binding activities of TNF-alpha and TNF-beta to the lung cancers, and the intrinsic TNFs-resistant cancer cells became susceptible to TNF-alpha and -beta. In addition, SM caused release of cytochrome c, downregulation of anti-apoptotic Bcl-2 and Bcl-xL, increase of caspase-3 activity, and DNA fragmentation. Thus, SM could modulate the expressions of TNFRs and Bcl-2, and might be a potential anticancer agent for TNFs and Bcl-2 related resistance of human lung cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Divisão Celular/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Alcaloides de Solanáceas/farmacologia , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral/genética
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