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1.
N Engl J Med ; 389(9): 795-807, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37646677

RESUMO

BACKGROUND: Among infants with isolated cleft palate, whether primary surgery at 6 months of age is more beneficial than surgery at 12 months of age with respect to speech outcomes, hearing outcomes, dentofacial development, and safety is unknown. METHODS: We randomly assigned infants with nonsyndromic isolated cleft palate, in a 1:1 ratio, to undergo standardized primary surgery at 6 months of age (6-month group) or at 12 months of age (12-month group) for closure of the cleft. Standardized assessments of quality-checked video and audio recordings at 1, 3, and 5 years of age were performed independently by speech and language therapists who were unaware of the trial-group assignments. The primary outcome was velopharyngeal insufficiency at 5 years of age, defined as a velopharyngeal composite summary score of at least 4 (scores range from 0 to 6, with higher scores indicating greater severity). Secondary outcomes included speech development, postoperative complications, hearing sensitivity, dentofacial development, and growth. RESULTS: We randomly assigned 558 infants at 23 centers across Europe and South America to undergo surgery at 6 months of age (281 infants) or at 12 months of age (277 infants). Speech recordings from 235 infants (83.6%) in the 6-month group and 226 (81.6%) in the 12-month group were analyzable. Insufficient velopharyngeal function at 5 years of age was observed in 21 of 235 infants (8.9%) in the 6-month group as compared with 34 of 226 (15.0%) in the 12-month group (risk ratio, 0.59; 95% confidence interval, 0.36 to 0.99; P = 0.04). Postoperative complications were infrequent and similar in the 6-month and 12-month groups. Four serious adverse events were reported (three in the 6-month group and one in the 12-month group) and had resolved at follow-up. CONCLUSIONS: Medically fit infants who underwent primary surgery for isolated cleft palate in adequately resourced settings at 6 months of age were less likely to have velopharyngeal insufficiency at the age of 5 years than those who had surgery at 12 months of age. (Funded by the National Institute of Dental and Craniofacial Research; TOPS ClinicalTrials.gov number, NCT00993551.).


Assuntos
Fissura Palatina , Insuficiência Velofaríngea , Pré-Escolar , Humanos , Lactente , Pessoal Técnico de Saúde , Fissura Palatina/complicações , Fissura Palatina/cirurgia , Europa (Continente) , Complicações Pós-Operatórias/epidemiologia , Insuficiência Velofaríngea/diagnóstico , Insuficiência Velofaríngea/etiologia , América do Sul , Técnicas de Diagnóstico por Cirurgia
2.
Cell Mol Life Sci ; 80(8): 216, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468729

RESUMO

During phagocytosis, endosomes both contribute with membrane to forming phagosomes and promote phagosome maturation. However, how these vesicles are delivered to the phagocytic cup and the phagosome has been unknown. Here, we show that Protrudin-mediated endoplasmic reticulum (ER)-endosome contact sites facilitate anterograde translocation of FYCO1 and VAMP7-positive late endosomes and lysosomes (LELys) to forming phagocytic cups in a retinal pigment epithelial-derived cell line (RPE1). Protrudin-dependent phagocytic cup formation required SYT7, which promotes fusion of LELys with the plasma membrane. RPE1 cells perform phagocytosis of dead cells (efferocytosis) that expose phosphatidylserine (PS) on their surface. Exogenous addition of apoptotic bodies increased the formation of phagocytic cups, which further increased when Protrudin was overexpressed. Overexpression of Protrudin also led to elevated uptake of silica beads coated with PS. Conversely, Protrudin depletion or abrogation of ER-endosome contact sites inhibited phagocytic cup formation resulting in reduced uptake of PS-coated beads. Thus, the Protrudin pathway delivers endosomes to facilitate formation of the phagocytic cup important for PS-dependent phagocytosis.


Assuntos
Retículo Endoplasmático , Fagocitose , Retículo Endoplasmático/metabolismo , Lisossomos/metabolismo , Fagossomos/metabolismo , Endossomos/metabolismo
3.
J Nat Prod ; 86(7): 1690-1697, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37411021

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen that causes a wide range of infections. Its resistance to ß-lactam antibiotics complicates treatment due to the limited number of antibiotics with activity against MRSA. To investigate development of alternative therapeutics, the mechanisms that mediate antibiotic resistance in MRSA need to be fully understood. In this study, MRSA cells were subjected to antibiotic stress from methicillin in combination with three cannabinoid compounds and analyzed using proteomics to assess the changes in physiology. Subjecting MRSA to nonlethal levels of methicillin resulted in an increased production of penicillin-binding protein 2 (PBP2). Exposure to cannabinoids showed antibiotic activity against MRSA, and differential proteomics revealed reduced levels of proteins involved in the energy production as well as PBP2 when used in combination with methicillin.


Assuntos
Canabinoides , Staphylococcus aureus Resistente à Meticilina , Humanos , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Meticilina/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/metabolismo , Proteômica , Canabinoides/química , Canabinoides/farmacologia
4.
Med Educ ; 56(6): 680-689, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35262226

RESUMO

BACKGROUND: Collaborative skills learning in the form of dyad learning compared with individual learning has been shown to lead to non-inferior skills retention and transfer. However, we have limited knowledge on which learning activities improve collaborative skills training and how the number of collaborators may impact skills transfer. We explored the effects of skills training individually, in dyads, triads or tetrads on learning activities during training and on subsequent skills transfer. METHODS: In a randomised, controlled study, participants completed a pre-post-transfer-test set-up in groups of one to four. Participants completed 2 hours of obstetric ultrasound training. In the dyad, triad and tetrad group participants took turns actively handling the ultrasound probe. All performances were rated by two blinded experts using the Objective Structured Assessment of Ultrasound Skills (OSAUS) scale and a Global Rating Scale (GRS). All training was video recorded, and learning activities were analysed using the Interactive-Constructive-Active-Passive (ICAP) framework. RESULTS: One hundred one participants completed the simulation-based training, and ninety-seven completed the transfer test. Performance scores improved significantly from pre- to post-test for all groups (p < 0.001, ηp2 = 0.55). However, group size did not affect transfer test performance on OSAUS scores (p = 0.13, ηp2 = 0.06) or GRS scores (p = 0.23, ηp2 = 0.05). ICAP analyses of training activities showed that time spent on non-learning and passive learning activities increased with group size (p < 0.001, ηp2 = 0.31), whereas time spent on constructive and interactive learning activities was constant between groups compared with singles (p < 0.001, ηp2 = 0.72). CONCLUSION: Collaborative skills learning in groups of up to four did not impair skills transfer despite less hands-on time. This may be explained by a compensatory shift towards constructive and interactive learning activities that outweigh the effect of shorter hands-on time.


Assuntos
Competência Clínica , Treinamento por Simulação , Avaliação Educacional , Humanos , Aprendizagem , Ultrassonografia
5.
Nature ; 520(7546): 234-8, 2015 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-25855459

RESUMO

The main organelles of the secretory and endocytic pathways--the endoplasmic reticulum (ER) and endosomes, respectively--are connected through contact sites whose numbers increase as endosomes mature. One function of such sites is to enable dephosphorylation of the cytosolic tails of endosomal signalling receptors by an ER-associated phosphatase, whereas others serve to negatively control the association of endosomes with the minus-end-directed microtubule motor dynein or mediate endosome fission. Cholesterol transfer and Ca(2+) exchange have been proposed as additional functions of such sites. However, the compositions, activities and regulations of ER-endosome contact sites remain incompletely understood. Here we show in human and rat cell lines that protrudin, an ER protein that promotes protrusion and neurite outgrowth, forms contact sites with late endosomes (LEs) via coincident detection of the small GTPase RAB7 and phosphatidylinositol 3-phosphate (PtdIns(3)P). These contact sites mediate transfer of the microtubule motor kinesin 1 from protrudin to the motor adaptor FYCO1 on LEs. Repeated LE-ER contacts promote microtubule-dependent translocation of LEs to the cell periphery and subsequent synaptotagmin-VII-dependent fusion with the plasma membrane. Such fusion induces outgrowth of protrusions and neurites, which requires the abilities of protrudin and FYCO1 to interact with LEs and kinesin 1. Thus, protrudin-containing ER-LE contact sites are platforms for kinesin-1 loading onto LEs, and kinesin-1-mediated translocation of LEs to the plasma membrane, fuelled by repeated ER contacts, promotes protrusion and neurite outgrowth.


Assuntos
Retículo Endoplasmático/metabolismo , Endossomos/metabolismo , Neuritos/metabolismo , Animais , Sítios de Ligação , Transporte Biológico , Linhagem Celular , Membrana Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Células HeLa , Humanos , Cinesinas/metabolismo , Proteínas Associadas aos Microtúbulos , Microtúbulos/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Ratos , Sinaptotagminas/metabolismo , Fatores de Transcrição/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7
6.
Cleft Palate Craniofac J ; 57(3): 352-363, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31928085

RESUMO

OBJECTIVE: To compare speech outcome following different sequencing of hard and soft palate closure between arms and centers within trial 3 and compare results to peers without cleft palate. DESIGN: A prospective randomized clinical trial. SETTING: Two Norwegian and 2 British centers. PARTICIPANTS: One hundred thirty-six 5-year-olds with unilateral cleft lip and palate were randomized to either lip and soft palate closure at 3 to 4 months and hard palate closure at 12 months (arm A) or lip and hard palate closure at 3 to 4 months and soft palate closure at 12 months (arm D). MAIN OUTCOME MEASURES: A composite measure of velopharyngeal competence (VPC), overall assessment of VPC from connected speech (VPC-Rate). Percentage of consonants correct (PCC), active cleft speech characteristics (CSCs), subdivided by oral retracted and nonoral errors, and developmental speech characteristics (DSCs). RESULTS: Across the trial, 47% had VPC, with no statistically significant difference between arms within or across centers. Thirty-eight percent achieved a PCC score of >90%, with no difference between arms or centers. In one center, significantly more children in arm A produced ≥3 active CSCs (P < .05). Across centers, there was a statistically significant difference in active CSCs (arm D), oral retracted CSCs (arm D), and DSCs (arms A and D). CONCLUSIONS: Less than half of the 5-year-olds achieved VPC and around one-third achieved age-appropriate PCC scores. Cleft speech characteristics were more common in arm A, but outcomes varied within and across centers. Thus, outcome of the same surgical method can vary substantially across centers.


Assuntos
Fenda Labial , Fissura Palatina , Criança , Humanos , Estudos Prospectivos , Fala , Distúrbios da Fala , Resultado do Tratamento
7.
Acta Obstet Gynecol Scand ; 98(1): 86-94, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30218572

RESUMO

INTRODUCTION: The aim of this study was to examine the association between plasma hormone concentrations, cervical length, and preterm delivery in twin pregnancies, including the effect of progesterone treatment. MATERIAL AND METHODS: This study included 191 women pregnant with twins from a randomized placebo-controlled trial. A baseline blood sample was collected at 18-24 weeks before treatment with vaginal progesterone (n = 95) or placebo pessaries (n = 96), and 167 (87.4%) women had a second sample collected after 4-8 weeks of treatment. At baseline, 155 (81.2%) women had their cervical length measured. Progesterone, estradiol, and unconjugated estriol concentration was measured, and the association between hormone concentrations, cervical length, and gestational age at delivery was examined. Hormone concentrations were compared in the placebo and progesterone group. Statistical analysis included Spearman's rho, Mann-Whitney U test, Cuzick's test for trends, and linear regression analyses. RESULTS: A short cervical length was associated with preterm delivery. Cervical length and hormone concentrations were not associated (Spearman's rho; progesterone -.05, estradiol .04, estriol .08). Decreasing gestational age at delivery was associated with higher progesterone and estradiol concentrations at baseline (P trend; progesterone 0.04, estradiol 0.02) but not in the second sample or in the weekly change between samples. Progesterone treatment did not increase the progesterone concentration. CONCLUSIONS: Plasma concentrations of progesterone, estradiol, and unconjugated estriol at 18-24 weeks are not associated with cervical length or preterm delivery in twin pregnancies. Vaginal progesterone treatment does not increase the circulating progesterone concentration in twin pregnancies. Cervical length, but not hormone concentration, is predictive of preterm delivery in twin gestations.


Assuntos
Medida do Comprimento Cervical , Estriol/sangue , Complicações na Gravidez/sangue , Gravidez de Gêmeos/sangue , Progesterona/sangue , Progestinas/sangue , Adulto , Estriol/administração & dosagem , Feminino , Humanos , Gravidez , Complicações na Gravidez/tratamento farmacológico , Resultado da Gravidez , Nascimento Prematuro/prevenção & controle , Progesterona/administração & dosagem , Progestinas/administração & dosagem
8.
Clin Linguist Phon ; 31(7-9): 589-597, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28362219

RESUMO

Overall weighted or composite variables for perceptual auditory estimation of velopharyngeal closure or competence have been used in several studies for evaluation of velopharyngeal function during speech. The aim of the present study was to investigate the validity of a composite score (VPC-Sum) and of auditory perceptual ratings of velopharyngeal competence (VPC-Rate). Available VPC-Sum scores and judgments of associated variables (hypernasality, audible nasal air leakage, weak pressure consonants, and non-oral articulation) from 391 5-year olds with repaired cleft palate (the Scandcleft project) were used to investigate content validity, and 339 of these were compared with an overall judgment of velopharyngeal competence (VPC-Rate) on the same patients by the same listeners. Significant positive correlations were found between the VPC-Sum and each of the associated variables (Cronbachs alpha 0.55-0.87, P < 0.001), and a moderately significant positive correlation between VPC-Sum and VPC-Rate (Rho 0.698, P < 0.01). The latter classified cases well when VPC-Sum was dichotomized with 67% predicted velopharyngeal competence and 90% velopharyngeal incompetence. The validity of the VPC-Sum was good and the VPC-Rate a good predictor, suggesting possible use of both measures depending on the objective.


Assuntos
Percepção Auditiva , Faringe/cirurgia , Fala , Insuficiência Velofaríngea/fisiopatologia , Criança , Fissura Palatina , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes
9.
Biochem Soc Trans ; 44(2): 425-30, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27068950

RESUMO

Cellular membranes communicate extensively via contact sites that form between two membranes. Such sites allow exchange of specific ions, lipids or proteins between two compartments without content mixing, thereby preserving organellar architecture during the transfer process. Even though the molecular compositions of membrane contact sites are diverse, it is striking that several of these sites, including contact sites between the endoplasmic reticulum (ER) and endosomes, Golgi and the plasma membrane (PM), and contact sites between lysosomes and peroxisomes, contain phosphorylated derivatives of phosphatidylinositol known as phosphoinositides. In this mini-review we discuss the involvement and functions of phosphoinositides in membrane contact sites.


Assuntos
Membrana Celular/metabolismo , Membranas Intracelulares/metabolismo , Fosfatidilinositóis/metabolismo , Animais , Sítios de Ligação , Humanos , Organelas/metabolismo
10.
Biochem Soc Trans ; 44(2): 441-6, 2016 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-27068952

RESUMO

The endoplasmic reticulum (ER) makes abundant contacts with endosomes, and the numbers of contact sites increase as endosomes mature. It is already clear that such contact sites have diverse compositions and functions, but in this mini-review we will focus on two particular types of ER-endosome contact sites that regulate endosome positioning. Formation of ER-endosome contact sites that contain the cholesterol-binding protein oxysterol-binding protein-related protein 1L (ORP1L) is coordinated with loss of the minus-end-directed microtubule motor Dynein from endosomes. Conversely, formation of ER-endosome contact sites that contain the Kinesin-1-binding protein Protrudin results in transfer of the plus-end-directed microtubule motor Kinesin-1 from ER to endosomes. We discuss the possibility that formation of these two types of contact sites is coordinated as a 'gear-shift' mechanism for endosome motility, and we review evidence that Kinesin-1-mediated motility of late endosomes (LEs) to the cell periphery promotes outgrowth of neurites and other protrusions.


Assuntos
Retículo Endoplasmático/metabolismo , Endossomos/metabolismo , Animais , Humanos , Proteínas de Membrana/metabolismo , Fosfatidilinositóis/metabolismo
11.
Reprod Biomed Online ; 32(6): 563-83, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27151490

RESUMO

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age and is the most common cause of anovulatory infertility. The treatment approaches to ovulation induction vary in efficacy, treatment duration and patient friendliness. The aim was to determine the most efficient, evidence-based method to achieve mono-ovulation in women diagnosed with PCOS. Publications in English providing information on treatment, efficacy and complication rates were included until September 2015. Systematic reviews, meta-analyses and randomized controlled trials were favoured over cohort and retrospective studies. Clomiphene citrate is recommended as primary treatment for PCOS-related infertility. It induces ovulation in three out of four patients, the risk of multiple pregnancies is modest and the treatment is simple and inexpensive. Gonadotrophins are highly efficient in a low-dose step-up regimen. Ovulation rates are improved by lifestyle interventions in overweight women. Metformin may improve the menstrual cycle within 1-3 months, but does not improve the live birth rate. Letrozole is effective for ovulation induction, but is an off-label drug in many countries. Ovulation induction in women with PCOS should be individualized with regard to weight, treatment efficacy and patient preferences with the aim of achieving mono-ovulation and subsequently the birth of a singleton baby.


Assuntos
Indução da Ovulação/métodos , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/terapia , Adulto , Anovulação/tratamento farmacológico , Peso Corporal , Clomifeno/uso terapêutico , Feminino , Fármacos para a Fertilidade Feminina/uso terapêutico , Gonadotropinas/sangue , Humanos , Infertilidade Feminina/tratamento farmacológico , Letrozol , Estilo de Vida , Metformina/química , Metformina/uso terapêutico , Nitrilas/química , Sobrepeso , Ovulação , Segurança do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto , Técnicas de Reprodução Assistida , Estudos Retrospectivos , Triazóis/química
12.
EMBO Rep ; 14(1): 57-64, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23154468

RESUMO

Although phosphatidylinositol 5-phosphate (PtdIns5P) is present in many cell types and its biogenesis is increased by diverse stimuli, its precise cellular function remains elusive. Here we show that PtdIns5P levels increase when cells are stimulated to move and we find PtdIns5P to promote cell migration in tissue culture and in a Drosophila in vivo model. First, class III phosphatidylinositol 3-kinase, which produces PtdIns3P, was shown to be involved in migration of fibroblasts. In a cell migration screen for proteins containing PtdIns3P-binding motifs, we identified the phosphoinositide 5-kinase PIKfyve and the phosphoinositide 3-phosphatase MTMR3, which together constitute a phosphoinositide loop that produces PtdIns5P via PtdIns(3,5)P(2). The ability of PtdIns5P to stimulate cell migration was demonstrated directly with exogenous PtdIns5P and a PtdIns5P-producing bacterial enzyme. Thus, the identified phosphoinositide loop defines a new role for PtdIns5P in cell migration.


Assuntos
Movimento Celular/fisiologia , Drosophila melanogaster/metabolismo , Fibroblastos/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/biossíntese , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Classe III de Fosfatidilinositol 3-Quinases/genética , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Drosophila melanogaster/genética , Fibroblastos/citologia , Regulação da Expressão Gênica , Humanos , Fosfatidilinositol 3-Quinases/genética , Fosfatos de Fosfatidilinositol/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Tirosina Fosfatases não Receptoras/antagonistas & inibidores , Proteínas Tirosina Fosfatases não Receptoras/genética , RNA Interferente Pequeno/genética , Transdução de Sinais
13.
Traffic ; 13(11): 1547-63, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22816767

RESUMO

Phosphatidylinositol 3-phosphate (PtdIns3P) orchestrates endosomal cargo transport, fusion and motility by recruiting FYVE or PX domain-containing effector proteins to endosomal membranes. In an attempt to discover novel PtdIns3P effectors involved in the termination of growth factor receptor signalling, we performed an siRNA screen for epidermal growth factor (EGF) degradation, targeting FYVE and PX domain proteins in the human proteome. This screen identified several potential regulators of EGF degradation, including HRS (used as positive control), PX kinase, MTMR4 and Phafin2/PLEKHF2. As Phafin2 has not previously been shown to be required for EGF receptor (EGFR) degradation, we performed further functional studies on this protein. Loss of Phafin2 was found to decrease early endosome size, whereas overexpression of Phafin2 resulted in enlarged endosomes. Moreover, both the EGFR and the fluid-phase marker dextran were retained in abnormally small endosomes in Phafin2-depleted cells. In yeast two-hybrid analysis we identified Phafin2 as a novel interactor of the endosomal-tethering protein EEA1, and Phafin2 colocalized strongly with EEA1 in microdomains of the endosome membrane. Our results suggest that Phafin2 controls receptor trafficking and fluid-phase transport through early endosomes by facilitating endosome fusion in concert with EEA1.


Assuntos
Endossomos/metabolismo , Receptores ErbB/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Motivos de Aminoácidos , Endocitose , Endossomos/ultraestrutura , Fator de Crescimento Epidérmico/metabolismo , Células HeLa , Ensaios de Triagem em Larga Escala , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Tamanho das Organelas , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/química , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Proteólise , Proteoma/química , Proteoma/metabolismo , RNA Interferente Pequeno , Técnicas do Sistema de Duplo-Híbrido , Regulação para Cima , Proteínas de Transporte Vesicular/química , Proteínas de Transporte Vesicular/genética
14.
Nat Commun ; 15(1): 1277, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341434

RESUMO

Overexpression of the transmembrane matrix metalloproteinase MT1-MMP/MMP14 promotes cancer cell invasion. Here we show that MT1-MMP-positive cancer cells turn MT1-MMP-negative cells invasive by transferring a soluble catalytic ectodomain of MT1-MMP. Surprisingly, this effect depends on the presence of TKS4 and TKS5 in the donor cell, adaptor proteins previously implicated in invadopodia formation. In endosomes of the donor cell, TKS4/5 promote ADAM-mediated cleavage of MT1-MMP by bridging the two proteases, and cleavage is stimulated by the low intraluminal pH of endosomes. The bridging depends on the PX domains of TKS4/5, which coincidently interact with the cytosolic tail of MT1-MMP and endosomal phosphatidylinositol 3-phosphate. MT1-MMP recruits TKS4/5 into multivesicular endosomes for their subsequent co-secretion in extracellular vesicles, together with the enzymatically active ectodomain. The shed ectodomain converts non-invasive recipient cells into an invasive phenotype. Thus, TKS4/5 promote intercellular transfer of cancer cell invasiveness by facilitating ADAM-mediated shedding of MT1-MMP in acidic endosomes.


Assuntos
Metaloproteinase 14 da Matriz , Neoplasias , Humanos , Metaloproteinase 14 da Matriz/genética , Metaloproteinase 14 da Matriz/metabolismo , Peptídeo Hidrolases/metabolismo , Neoplasias/genética , Endossomos/metabolismo , Invasividade Neoplásica , Linhagem Celular Tumoral
15.
Traffic ; 12(9): 1211-26, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21564451

RESUMO

Ligand-mediated lysosomal degradation of growth factor receptors, mediated by the endosomal sorting complex required for transport (ESCRT) machinery, is a mechanism that attenuates the cellular response to growth factors. In this article, we present a novel regulatory mechanism that involves ligand-mediated degradation of a key component of the sorting machinery itself. We have investigated the endosomal localization of subunits of the four ESCRTs-Hrs (ESCRT-0), Tsg101 (ESCRT-I), EAP30/Vps22 (ESCRT-II) and charged multivesicular body protein 3/Vps24 (ESCRT-III). All the components were detected on the limiting membrane of multivesicular endosomes (MVEs). Surprisingly, however, Tsg101 and other ESCRT-I subunits were also detected within intraluminal vesicles (ILVs) of MVEs. Tsg101 was sequestered along with cargo during endosomal sorting into ILVs and further degraded in lysosomes. Importantly, ESCRT-mediated downregulation of two distinct cargoes, epidermal growth factor receptor (EGFR) and connexin43, mutually made cells refractory to degradation of the other cargo. Our observations indicate that the degradation of a key ESCRT component along with cargo represents a novel feedback control of endosomal sorting by preventing collateral degradation of cell surface receptors following stimulation of one specific pathway.


Assuntos
Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Endossomos/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Retroalimentação Fisiológica , Linhagem Celular , Meios de Cultura Livres de Soro , Vesículas Citoplasmáticas/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Humanos , Lisossomos/metabolismo , Transporte Proteico/fisiologia , RNA Interferente Pequeno/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
Sci Rep ; 13(1): 22982, 2023 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-38151514

RESUMO

The ability of cells to move and migrate is required during development, but also in the adult in processes such as wound healing and immune responses. In addition, cancer cells exploit the cells' ability to migrate and invade to spread into nearby tissue and eventually metastasize. The majority of cancer deaths are caused by metastasis and the process of cell migration is therefore intensively studied. A common way to study cell migration is to observe cells through an optical microscope and record their movements over time. However, segmenting and tracking moving cells in phase contrast time-lapse video sequences is a challenging task. Several tools to track the velocity of migrating cells have been developed. Unfortunately, most of the automated tools are made for fluorescence images even though unlabelled cells are often preferred to avoid phototoxicity. Consequently, researchers are constrained with laborious manual tracking tools using ImageJ or similar software. We have therefore developed a freely available, user-friendly, automated tracking tool called CellTraxx. This software makes it easy to measure the velocity and directness of migrating cells in phase contrast images. Here, we demonstrate that our tool efficiently recognizes and tracks unlabelled cells of different morphologies and sizes (HeLa, RPE1, MDA-MB-231, HT1080, U2OS, PC-3) in several types of cell migration assays (random migration, wound healing and cells embedded in collagen). We also provide a detailed protocol and download instructions for CellTraxx.


Assuntos
Software , Cicatrização , Adulto , Humanos , Movimento Celular/fisiologia , Células HeLa , Cicatrização/fisiologia , Ensaios de Migração Celular/métodos , Rastreamento de Células/métodos , Processamento de Imagem Assistida por Computador/métodos
17.
Carcinogenesis ; 33(5): 1031-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22436610

RESUMO

The oncoprotein ErbB3 is overexpressed in several human cancers, for example in pancreatic adenocarcinoma and in ovarian cancers, and ErbB3-containing heterodimers have been demonstrated to be potent signaling units in carcinogenesis. This especially applies to ErbB2-ErbB3 and epidermal growth factor receptor (EGFR)-ErbB3 heterodimers providing anti-apoptotic signaling. Relatively little is understood about the signaling of EGFR-ErbB3 heterodimers and especially about mechanisms involved in downregulation of ErbB3 from the plasma membrane. This is in contrast to EGFR homodimers, for which trafficking has been extensively characterized. In the present study, we have investigated mechanisms involved in endocytosis of ErbB3 in porcine aortic endothelial cells stably expressing either ErbB3 only or stably expressing ErbB3 and EGFR. Our data show that ErbB3 is endocytosed in the absence of added ligand, independently of its tyrosine phosphorylation state and in a clathrin-dependent manner. Functional EGFR-ErbB3 heterodimers were observed to be formed, and dimerization with ErbB3 was observed to negatively affect endocytosis of the EGFR.


Assuntos
Clatrina/metabolismo , Proteínas Oncogênicas/metabolismo , Receptor ErbB-3/metabolismo , Animais , Apoptose/fisiologia , Membrana Celular/metabolismo , Dimerização , Endocitose , Células Endoteliais/metabolismo , Receptores ErbB/metabolismo , Células HeLa , Hemeproteínas/metabolismo , Humanos , Ligantes , Fosforilação , Receptor ErbB-2/metabolismo , Transdução de Sinais/fisiologia , Suínos , Células Tumorais Cultivadas
18.
Exp Cell Res ; 317(13): 1804-16, 2011 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21635887

RESUMO

CIN85 has been demonstrated to interact with a number of proteins involved in endocytosis and intracellular sorting. However, the exact functional role of CIN85 in endocytosis remains unclear. We have investigated whether CIN85 plays a role in EGF-induced EGF receptor (EGFR) internalization, as previously suggested, or whether CIN85 is rather involved in endosomal sorting of the EGFR. When over-expressing a dominant negative interfering CIN85 mutant consisting of three SH3 domains only, we found that internalization of EGF was inhibited. However, when knocking down CIN85 by RNAi, the EGF-EGFR uptake appeared similar to in control cells. Furthermore, in CIN85 depleted cells, EGF-induced ubiquitination of the EGFR was decreased, and degradation of EGF-EGFR complexes was delayed. Our data further demonstrated that depletion of CIN85 increased the recycling of EGF, suggesting that CIN85 plays a role in endosomal sorting of the ubiquitinated EGFR. Our data also demonstrated that CIN85 was constitutively associated with Hrs, and this strengthens the hypothesis of a functional role of CIN85 in endosomal EGFR sorting.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Endossomos/metabolismo , Receptores ErbB/metabolismo , Ubiquitinação , Células Cultivadas , Fator de Crescimento Epidérmico/metabolismo , Células HeLa , Humanos , Proteínas Recombinantes/metabolismo
19.
Exp Cell Res ; 316(20): 3368-78, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20643123

RESUMO

The mammalian class III phosphatidylinositol 3-kinase (PI3K-III) complex regulates fundamental cellular functions, including growth factor receptor degradation, cytokinesis and autophagy. Recent studies suggest the existence of distinct PI3K-III sub-complexes that can potentially confer functional specificity. While a substantial body of work has focused on the roles of individual PI3K-III subunits in autophagy, functional studies on their contribution to endocytic receptor downregulation and cytokinesis are limited. We therefore sought to elucidate the specific nature of the PI3K-III complexes involved in these two processes. High-content microscopy-based assays combined with siRNA-mediated depletion of individual subunits indicated that a specific sub-complex containing VPS15, VPS34, Beclin 1, UVRAG and BIF-1 regulates both receptor degradation and cytokinesis, whereas ATG14L, a PI3K-III subunit involved in autophagy, is not required. The unanticipated role of UVRAG and BIF-1 in cytokinesis was supported by a strong localisation of these proteins to the midbody. Importantly, while the tumour suppressive functions of Beclin 1, UVRAG and BIF-1 have previously been ascribed to their roles in autophagy, these results open the possibility that they may also contribute to tumour suppression via downregulation of mitogenic signalling by growth factor receptors or preclusion of aneuploidy by ensuring faithful completion of cell division.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Citocinese/fisiologia , Endocitose/fisiologia , Proteínas de Membrana/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína VPS15 de Distribuição Vacuolar/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Proteínas Reguladoras de Apoptose/genética , Aurora Quinases , Proteínas Relacionadas à Autofagia , Proteína Beclina-1 , Classe III de Fosfatidilinositol 3-Quinases/genética , Estruturas Citoplasmáticas/metabolismo , Regulação para Baixo/fisiologia , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Células HeLa , Humanos , Proteínas de Membrana/genética , Modelos Biológicos , Complexos Multiproteicos/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno/genética , Proteínas Supressoras de Tumor/genética , Proteína VPS15 de Distribuição Vacuolar/genética
20.
Micromachines (Basel) ; 12(5)2021 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067628

RESUMO

Pyrolytic carbon microelectrodes (PCMEs) are a promising alternative to their conventional metallic counterparts for various applications. Thus, methods for the simple and inexpensive patterning of PCMEs are highly sought after. Here, we demonstrate the fabrication of PCMEs through the selective pyrolysis of SU-8 photoresist by irradiation with a low-power, 806 nm, continuous wave, semiconductor-diode laser. The SU-8 was modified by adding Pro-Jet 800NP (FujiFilm) in order to ensure absorbance in the 800 nm range. The SU-8 precursor with absorber was successfully converted into pyrolytic carbon upon laser irradiation, which was not possible without an absorber. We demonstrated that the local laser pyrolysis (LLP) process in an inert nitrogen atmosphere with higher laser power and lower scan speed resulted in higher electrical conductance. The maximum conductivity achieved for a laser-pyrolyzed line was 14.2 ± 3.3 S/cm, with a line width and thickness of 28.3 ± 2.9 µm and 6.0 ± 1.0 µm, respectively, while the narrowest conductive line was just 13.5 ± 0.4 µm wide and 4.9 ± 0.5 µm thick. The LLP process seemed to be self-limiting, as multiple repetitive laser scans did not alter the properties of the carbonized lines. The direct laser writing of adjacent lines with an insulating gap down to ≤5 µm was achieved. Finally, multiple lines were seamlessly joined and intersected, enabling the writing of more complex designs with branching electrodes and the porosity of the carbon lines could be controlled by the scan speed.

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