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1.
Disaster Med Public Health Prep ; 18: e94, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38812439

RESUMO

Terrorist attacks involving children raised concern regarding the preparedness to treat pediatric trauma patients during mass casualty incidents (MCIs). The purpose of this project was to assess the resources available in Milan to respond to MCIs as the 2016 Bastille Day attack in Nice. Literature and guidelines were reviewed and minimal standard requirements of care of pediatric trauma patients in MCIs were identified. The hospitals that took part in the study were asked to answer a survey regarding their resource availability. An overall surge capability of 40-44 pediatric trauma patients was identified, distributed based on age and severity, hospital resources, and expertise. The findings showed that adult and pediatric hospitals should work in synergy with pediatric trauma centers, or offer an alternative if there is none, and should be included in disaster plans for MCIs. Simulations exercises need to be carried out to evaluate and validate the results.


Assuntos
Planejamento em Desastres , Incidentes com Feridos em Massa , Terrorismo , Humanos , Incidentes com Feridos em Massa/estatística & dados numéricos , Itália , Planejamento em Desastres/métodos , Terrorismo/estatística & dados numéricos , Criança , Inquéritos e Questionários , Pediatria/métodos , Pediatria/estatística & dados numéricos , Pediatria/normas , Pré-Escolar , Adolescente , Capacidade de Resposta ante Emergências/estatística & dados numéricos
2.
Dev Cell ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38815583

RESUMO

Local mRNA translation in axons is critical for the spatiotemporal regulation of the axonal proteome. A wide variety of mRNAs are localized and translated in axons; however, how protein synthesis is regulated at specific subcellular sites in axons remains unclear. Here, we establish that the axonal endoplasmic reticulum (ER) supports axonal translation in developing rat hippocampal cultured neurons. Axonal ER tubule disruption impairs local translation and ribosome distribution. Using nanoscale resolution imaging, we find that ribosomes make frequent contacts with axonal ER tubules in a translation-dependent manner and are influenced by specific extrinsic cues. We identify P180/RRBP1 as an axonally distributed ribosome receptor that regulates local translation and binds to mRNAs enriched for axonal membrane proteins. Importantly, the impairment of axonal ER-ribosome interactions causes defects in axon morphology. Our results establish a role for the axonal ER in dynamically localizing mRNA translation, which is important for proper neuron development.

3.
Prehosp Disaster Med ; : 1-4, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38654669

RESUMO

This field report presents the planning and execution of a large-scale aeromedical refugee retrieval operation amid the on-going Russia-Ukraine crisis. The retrieval was coordinated by the Italian Department of Civil Protection and led by the Centrale Remota Operazioni Soccorso Sanitario (CROSS), a governmental facility overseeing medical assistance. An Airbus A320 was chosen for its capacity of 165 passengers, with one emergency stretcher maintaining maximum seating. The aircraft was equipped with an Advanced Life Support kit, and specific considerations for medical equipment compliance were made. Special cases, including patients with on-going chemotherapy and end-stage kidney disease, underwent fit-to-fly screening. The boarding process in Lublin, Poland involved triage and arrangements for passengers with gastroenteric symptoms. Notably, 22 passengers with recent episodes of illness were isolated. The successful operation, demonstrating the viability of evacuating vulnerable individuals via commercial airlines, underscores the importance of precise planning and coordination in crisis situations.

4.
Nat Cell Biol ; 26(3): 404-420, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38424271

RESUMO

γ-Tubulin ring complex (γ-TuRC) is the major microtubule-nucleating factor. After nucleation, microtubules can be released from γ-TuRC and stabilized by other proteins, such as CAMSAPs, but the biochemical cross-talk between minus-end regulation pathways is poorly understood. Here we reconstituted this process in vitro using purified components. We found that all CAMSAPs could bind to the minus ends of γ-TuRC-attached microtubules. CAMSAP2 and CAMSAP3, which decorate and stabilize growing minus ends but not the minus-end tracking protein CAMSAP1, induced microtubule release from γ-TuRC. CDK5RAP2, a γ-TuRC-interactor, and CLASP2, a regulator of microtubule growth, strongly stimulated γ-TuRC-dependent microtubule nucleation, but only CDK5RAP2 suppressed CAMSAP binding to γ-TuRC-anchored minus ends and their release. CDK5RAP2 also improved selectivity of γ-tubulin-containing complexes for 13- rather than 14-protofilament microtubules in microtubule-capping assays. Knockout and overexpression experiments in cells showed that CDK5RAP2 inhibits the formation of CAMSAP2-bound microtubules detached from the microtubule-organizing centre. We conclude that CAMSAPs can release newly nucleated microtubules from γ-TuRC, whereas nucleation-promoting factors can differentially regulate this process.


Assuntos
Proteínas Associadas aos Microtúbulos , Tubulina (Proteína) , Tubulina (Proteína)/metabolismo , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Centro Organizador dos Microtúbulos/metabolismo , Citoesqueleto/metabolismo
5.
Disaster Med Public Health Prep ; 17: e563, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38093634

RESUMO

On July 7, 2023, at 1:21 am, a fire was declared in a retirement home in Milan, Italy. The number of casualties (n = 87) according to the Simple Triage and Rapid Treatment (START) triage system was categorized as 65 green, 14 yellow, 2 red, and 6 black; 75% were women, and the mean age was 85.1 years (± 9). Most patients were unable to walk. A total of 30 basic life support (BLS) ambulances, 3 advanced cardiac life support (ACLS) teams on fast cars, 2 buses, and 1 coordination team were deployed. A scoop and run approach was adopted with patients being transported to 15 health care facilities. The event was terminated at 5:43 am. Though the local mass casualty incident (MCI) response plan was correctly applied, the evacuation of the building was difficult due to the age and comorbidities of the patients. START failed to correctly identify patients categorized as minor. Communication problems arose on site that led to the late evacuation of critical patients.


Assuntos
Planejamento em Desastres , Serviços Médicos de Emergência , Incidentes com Feridos em Massa , Humanos , Feminino , Idoso de 80 Anos ou mais , Masculino , Triagem , Casas de Saúde , Itália
6.
Prehosp Disaster Med ; 38(6): 725-734, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37997379

RESUMO

INTRODUCTION: Effective response to a mass-casualty incident (MCI) entails the activation of hospital MCI plans. Unfortunately, there are no tools available in the literature to support hospital responders in predicting the proper level of MCI plan activation. This manuscript describes the scientific-based approach used to develop, test, and validate the PEMAAF score (Proximity, Event, Multitude, Overcrowding, Temporary Ward Reduction Capacity, Time Shift Slot [Prossimità, Evento, Moltitudine, Affollamento, Accorpamento, Fascia Oraria], a tool able to predict the required level of hospital MCI plan activation and to facilitate a coordinated activation of a multi-hospital network. METHODS: Three study phases were performed within the Metropolitan City of Milan, Italy: (1) retrospective analysis of past MCI after action reports (AARs); (2) PEMAAF score development; and (3) PEMAAF score validation. The validation phase entailed a multi-step process including two retrospective analyses of past MCIs using the score, a focus group discussion (FGD), and a prospective simulation-based study. Sensitivity and specificity of the score were analyzed using a regression model, Spearman's Rho test, and receiver operating characteristic/ROC analysis curves. RESULTS: Results of the retrospective analysis and FGD were used to refine the PEMAAF score, which included six items-Proximity, Event, Multitude, Emergency Department (ED) Overcrowding, Temporary Ward Reduction Capacity, and Time Shift Slot-allowing for the identification of three priority levels (score of 5-6: green alert; score of 7-9: yellow alert; and score of 10-12: red alert). When prospectively analyzed, the PEMAAF score determined most frequent hospital MCI plan activation (>10) during night and holiday shifts, with a score of 11 being associated with a higher sensitivity system and a score of 12 with higher specificity. CONCLUSIONS: The PEMAAF score allowed for a balanced and adequately distributed response in case of MCI, prompting hospital MCI plan activation according to real needs, taking into consideration the whole hospital response network.


Assuntos
Planejamento em Desastres , Incidentes com Feridos em Massa , Humanos , Estudos Retrospectivos , Serviço Hospitalar de Emergência , Hospitais , Triagem
7.
Disaster Med Public Health Prep ; 17: e480, 2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37667885

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerging infectious disease pandemic developed in Lombardy (northern Italy) during the last week of February 2020 with a progressive increase of patients presenting with serious clinical findings. Despite the efforts of the Central Italian Government, regional resources were rapidly at capacity. The solution was to plan the medical evacuation (MEDEVAC) of 119 critically ill patients (median age 61 years) to in-patient intensive care units in other Italian regions (77) and Germany (42). Once surviving patients were deemed suitable, the repatriation process concluded the assignment. The aim of this report is to underline the importance of a rapid organization and coordination process between different nodes of an effective national and international network during an emerging infectious disease outbreak and draw lessons learned from similar published reports.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Pessoa de Meia-Idade , COVID-19/epidemiologia , Pandemias , Surtos de Doenças , Governo Federal
8.
Disaster Med Public Health Prep ; 17: e468, 2023 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-37477015

RESUMO

OBJECTIVE: To describe the health-care resources implemented during the Italian Formula 1 Grand Prix (F1GP) and to calculate the patient presentation rate (PPR) based on both real data and a prediction model. METHODS: Observational and descriptive study conducted from September 9 to September 11, 2022, during the Italian F1GP hosted in Monza (Italy). Maurer's formula was applied to decide the number and type of health resources to be allocated. Patient presentation rate (PPR) was computed based on real data (PPR_real) and based on the Arbon formula (PPR_est). RESULTS: Of 336,000 attendees, n = 263 requested medical assistance with most of them receiving treatment at the advanced medical post, and n = 16 needing transport to the hospital. The PPR_real was 51 for Friday, 78 for Saturday, 134 for Sunday, and 263 when considering the whole event as a single event. The PPR_est resulted in 85 for Friday, 93 for Saturday, 97 for Sunday, and 221 for the total population. CONCLUSIONS: A careful organization of health-care resources could mitigate the impact of the Italian F1GP on local hospital facilities. The Arbon formula is an acceptable model to predict and estimate the number of patients requesting medical assistance, but further investigation needs to be conducted to implement the model and tailor it to broader categories of MGE.


Assuntos
Serviços Médicos de Emergência , Humanos , Eventos de Massa , Aglomeração , Aniversários e Eventos Especiais , Itália
9.
Sci Transl Med ; 15(697): eadf2281, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-37224228

RESUMO

Glioblastoma is the most aggressive primary brain tumor with an unmet need for more effective therapies. Here, we investigated combination therapies based on L19TNF, an antibody-cytokine fusion protein based on tumor necrosis factor that selectively localizes to cancer neovasculature. Using immunocompetent orthotopic glioma mouse models, we identified strong anti-glioma activity of L19TNF in combination with the alkylating agent CCNU, which cured the majority of tumor-bearing mice, whereas monotherapies only had limited efficacy. In situ and ex vivo immunophenotypic and molecular profiling in the mouse models revealed that L19TNF and CCNU induced tumor DNA damage and treatment-associated tumor necrosis. In addition, this combination also up-regulated tumor endothelial cell adhesion molecules, promoted the infiltration of immune cells into the tumor, induced immunostimulatory pathways, and decreased immunosuppression pathways. MHC immunopeptidomics demonstrated that L19TNF and CCNU increased antigen presentation on MHC class I molecules. The antitumor activity was T cell dependent and completely abrogated in immunodeficient mouse models. On the basis of these encouraging results, we translated this treatment combination to patients with glioblastoma. The clinical translation is ongoing but already shows objective responses in three of five patients in the first recurrent glioblastoma patient cohort treated with L19TNF in combination with CCNU (NCT04573192).


Assuntos
Glioblastoma , Animais , Camundongos , Glioblastoma/tratamento farmacológico , Linfócitos T , Recidiva Local de Neoplasia , Fator de Necrose Tumoral alfa , Modelos Animais de Doenças , Lomustina
10.
Clin Cancer Res ; 28(24): 5440-5454, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36215129

RESUMO

PURPOSE: Small molecule drug conjugates (SMDC) are modular anticancer prodrugs that include a tumor-targeting small organic ligand, a cleavable linker, and a potent cytotoxic agent. Most of the SMDC products that have been developed for clinical applications target internalizing tumor-associated antigens on the surface of tumor cells. We have recently described a novel non-internalizing small organic ligand (named OncoFAP) of fibroblast activation protein (FAP), a tumor-associated antigen highly expressed in the stroma of most solid human malignancies. EXPERIMENTAL DESIGN: In this article, we describe a new series of OncoFAP-Drug derivatives based on monomethyl auristatin E (MMAE; a potent cytotoxic tubulin poison) and dipeptide linkers that are selectively cleaved by FAP in the tumor microenvironment. RESULTS: The tumor-targeting potential of OncoFAP was confirmed in patients with cancer using nuclear medicine procedures. We used mass spectrometry methodologies to quantify the amount of prodrug delivered to tumors and normal organs, as well as the efficiency of the drug release process. Linkers previously exploited for anticancer drug conjugates were used as benchmark. We identified OncoFAP-Gly-Pro-MMAE as the best performing SMDC, which has now been prioritized for further clinical development. OncoFAP-Gly-Pro-MMAE selectively delivered more than 10% injected dose per gram of MMAE to FAP-positive tumors, with a tumor-to-kidney ratio of 16:1 at 24 hours post-injection. CONCLUSIONS: The FAP-specific drug conjugates described in this article promise to be efficacious for the targeting of human malignancies. The extracellular release of potent anticancer payloads mediates durable complete remission in difficult-to-treat animal models of cancer.


Assuntos
Antineoplásicos , Imunoconjugados , Pró-Fármacos , Animais , Humanos , Imunoconjugados/química , Linhagem Celular Tumoral , Ligantes , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Pró-Fármacos/uso terapêutico , Antígenos de Neoplasias , Fibroblastos/metabolismo
11.
Development ; 149(16)2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35980365

RESUMO

In embryos of most animal species, the zygotic centrosome is assembled by the centriole derived from the sperm cell and pericentriolar proteins present in the oocyte. This zygotic centrosome acts as a microtubule organizing center (MTOC) to assemble the sperm aster and mitotic spindle. As MTOC formation has been studied mainly in adult cells, very little is known about the formation of the zygotic MTOC. Here, we show that zebrafish (Danio rerio) embryos lacking either maternal or paternal Cfap53, a centriolar satellite protein, arrest during the first cell cycle. Although Cfap53 is dispensable for sperm aster function, it aids proper formation of the mitotic spindle. During cell division, Cfap53 colocalizes with γ-tubulin and with other centrosomal and centriolar satellite proteins at the MTOC. Furthermore, we find that γ-tubulin localization at the MTOC is impaired in the absence of Cfap53. Based on these results, we propose a model in which Cfap53 deposited in the oocyte and the sperm participates in the organization of the zygotic MTOC to allow mitotic spindle formation.


Assuntos
Centríolos , Centro Organizador dos Microtúbulos , Animais , Centríolos/metabolismo , Centrossomo/metabolismo , Masculino , Centro Organizador dos Microtúbulos/metabolismo , Sêmen/metabolismo , Tubulina (Proteína)/metabolismo , Peixe-Zebra/metabolismo
12.
Anal Chem ; 94(30): 10715-10721, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35820828

RESUMO

Nuclear medicine plays a key role in modern diagnosis and cancer therapy. The development of tumor-targeting radionuclide conjugates (also named small molecule-radio conjugates (SMRCs)) represents a significant improvement over the clinical use of metabolic radiotracers (e.g., [18F]-fluorodeoxyglucose) for imaging and over the application of biocidal external beam radiations for therapy. During the discovery of SMRCs, molecular candidates must be carefully evaluated typically by performing biodistribution assays in preclinical tumor models. Quantification methodologies based on radioactive counts are typically demanding due to safety concerns, availability of radioactive materials, and infrastructures. In this article, we report the development of a mass spectrometry (MS)-based method for the detection and quantification of small molecule-metal conjugates (SMMCs) as cold surrogates of SMRCs. We applied this methodology for the evaluation of the biodistribution of a particular class of tumor-targeting drug candidates based on natLu, natGa, and natF and directed against fibroblast activation protein (FAP). The reliability of the liquid chromatography-MS (LC-MS) analysis was validated by a direct comparison of MS-based and radioactivity-based biodistribution data. The results show that MS biodistribution of stable isotope metal conjugates is an orthogonal tool for the preclinical characterization of different classes of radiopharmaceuticals.


Assuntos
Neoplasias , Compostos Radiofarmacêuticos , Humanos , Espectrometria de Massas , Metais , Radioisótopos , Reprodutibilidade dos Testes , Distribuição Tecidual
13.
Disaster Med Public Health Prep ; 17: e194, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35361295

RESUMO

OBJECTIVES: In mass casualty scenarios, patients with apparent hemodynamic and respiratory stability might have occult life-threatening injuries. These patients could benefit from more accurate triage methods. This study assessed the impact of point-of-care ultrasound on the accuracy of secondary triage conducted at an advanced medical post to enhance the detection of patients who, despite their apparent clinically stable condition, could benefit from earlier evacuation to definitive care or immediate life-saving treatment. METHODS: A mass casualty simulated event consisting of a bomb blast in a remote area was conducted with 10 simulated casualties classified as YELLOW at the primary triage scene; patients were evaluated by 4 physicians at an advanced medical post. Three patients had, respectively, hemoperitoneum, pneumothorax, and hemothorax. Only 2 physicians had sonographic information. RESULTS: All 4 physicians were able to suspect hemoperitoneum as a possible critical condition to be managed first, but only physicians with additional sonographic information accurately detected pneumothorax and hemothorax, thus deciding to immediately evacuate or treat.


Assuntos
Serviços Médicos de Emergência , Incidentes com Feridos em Massa , Pneumotórax , Humanos , Triagem/métodos , Serviços Médicos de Emergência/métodos , Projetos Piloto , Hemoperitônio , Hemotórax/diagnóstico por imagem , Hemotórax/etiologia , Sistemas Automatizados de Assistência Junto ao Leito
14.
J Biol Chem ; 298(4): 101786, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35247383

RESUMO

Crumbs proteins are evolutionarily conserved transmembrane proteins with essential roles in promoting the formation of the apical domain in epithelial cells. The short intracellular tail of Crumbs proteins are known to interact with several proteins, including the scaffolding protein PALS1 (protein associated with LIN7, Stardust in Drosophila). PALS1 in turn binds to a second scaffolding protein PATJ (PALS1-associated tight junction protein) to form the core Crumbs/PALS1/PATJ complex. While essential roles in epithelial organization have been shown for Crumbs proteins in Drosophila and mammalian systems, the three Caenorhabditis elegans crumbs genes are dispensable for epithelial polarization and development. Here, we investigated the presence and function of PALS1 and PATJ orthologs in C. elegans. We identified MAGU-2 as the C. elegans ortholog of PALS1 and show that MAGU-2 interacts with all three Crumbs proteins and localizes to the apical membrane domain of intestinal epithelial cells in a Crumbs-dependent fashion. Similar to crumbs mutants, magu-2 deletion showed no epithelial polarity defects. We also identified MPZ-1 as a candidate ortholog of PATJ based on the physical interaction with MAGU-2 and sequence similarity with PATJ proteins. However, MPZ-1 is not broadly expressed in epithelial tissues and, therefore, not likely a core component of the C. elegans Crumbs complex. Finally, we show overexpression of the Crumbs proteins EAT-20 or CRB-3 can lead to apical membrane expansion in the intestine. Our results shed light on the composition of the C. elegans Crumbs complex and indicate that the role of Crumbs proteins in promoting apical domain formation is conserved.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Polaridade Celular/genética , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Epitélio/metabolismo
15.
Disaster Med Public Health Prep ; 16(2): 829-834, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33583481

RESUMO

On January 25, 2018 a 5-car train derailed in Pioltello, 10 kilometers North-East of Milano City. A standardized post-hoc form was distributed to the hospitals involved in the management of the victims and allowed for an evaluation of the response to the incident.The management of the incident by EMS (Emergency Medical System) was effective in terms of organization of the scene and distribution of the patients, although the time for the first severe patient to reach the closest appropriate hospital was very long (2 hours). This can be partially explained by the extrication time.None of the alerted hospitals exceeded their capacity, as patients were distributed carefully among the hospitals. The overall outcome was quite satisfactory; no deaths were reported except for those on scene. Some responding hospitals reported that there was an over-activation based on the services ultimately needed. However this is common in MCIs, as an over-activation is preferable to an under-estimation. To address this concern, as more data are available, activation should be scaled down based on a plan established prior to it; this mechanism of scaling down seems to have failed in this event.It is of note that the highest performing hospitals underwent recently to an educational program on MCI management.


Assuntos
Planejamento em Desastres , Serviços Médicos de Emergência , Incidentes com Feridos em Massa , Serviço Hospitalar de Emergência , Hospitais , Humanos , Triagem
16.
Cell Rep ; 36(2): 109371, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34260930

RESUMO

Axons and dendrites are long extensions of neurons that contain arrays of noncentrosomal microtubules. Calmodulin-regulated spectrin-associated proteins (CAMSAPs) bind to and stabilize free microtubule minus ends and are critical for proper neuronal development and function. Previous studies have shown that the microtubule-severing ATPase katanin interacts with CAMSAPs and limits the length of CAMSAP-decorated microtubule stretches. However, how CAMSAP and microtubule minus end dynamics are regulated in neurons is poorly understood. Here, we show that the neuron-enriched protein WDR47 interacts with CAMSAPs and is critical for axon and dendrite development. We find that WDR47 accumulates at CAMSAP2-decorated microtubules, is essential for maintaining CAMSAP2 stretches, and protects minus ends from katanin-mediated severing. We propose a model where WDR47 protects CAMSAP2 at microtubule minus ends from katanin activity to ensure proper stabilization of the neuronal microtubule network.


Assuntos
Katanina , Proteínas Associadas aos Microtúbulos , Microtúbulos , Neurônios , Neuroproteção , Animais , Feminino , Humanos , Axônios/metabolismo , Chlorocebus aethiops , Células COS , Dendritos/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Katanina/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Neurônios/metabolismo , Ligação Proteica , Ratos Wistar
18.
Curr Biol ; 31(11): 2334-2346.e9, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33857431

RESUMO

Epithelial tubes are essential components of metazoan organ systems that control the flow of fluids and the exchange of materials between body compartments and the outside environment. The size and shape of the central lumen confer important characteristics to tubular organs and need to be carefully controlled. Here, we identify the small coiled-coil protein BBLN-1 as a regulator of lumen morphology in the C. elegans intestine. Loss of BBLN-1 causes the formation of bubble-shaped invaginations of the apical membrane into the cytoplasm of intestinal cells and abnormal aggregation of the subapical intermediate filament (IF) network. BBLN-1 interacts with IF proteins and localizes to the IF network in an IF-dependent manner. The appearance of invaginations is a result of the abnormal IF aggregation, indicating a direct role for the IF network in maintaining lumen homeostasis. Finally, we identify bublin (BBLN) as the mammalian ortholog of BBLN-1. When expressed in the C. elegans intestine, BBLN recapitulates the localization pattern of BBLN-1 and can compensate for the loss of BBLN-1 in early larvae. In mouse intestinal organoids, BBLN localizes subapically, together with the IF protein keratin 8. Our results therefore may have implications for understanding the role of IFs in regulating epithelial tube morphology in mammals.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Filamentos Intermediários , Filamentos Intermediários , Intestinos , Camundongos
19.
EMBO J ; 40(10): e106798, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33835529

RESUMO

Axon formation critically relies on local microtubule remodeling and marks the first step in establishing neuronal polarity. However, the function of the microtubule-organizing centrosomes during the onset of axon formation is still under debate. Here, we demonstrate that centrosomes play an essential role in controlling axon formation in human-induced pluripotent stem cell (iPSC)-derived neurons. Depleting centrioles, the core components of centrosomes, in unpolarized human neuronal stem cells results in various axon developmental defects at later stages, including immature action potential firing, mislocalization of axonal microtubule-associated Trim46 proteins, suppressed expression of growth cone proteins, and affected growth cone morphologies. Live-cell imaging of microtubules reveals that centriole loss impairs axonal microtubule reorganization toward the unique parallel plus-end out microtubule bundles during early development. We propose that centrosomes mediate microtubule remodeling during early axon development in human iPSC-derived neurons, thereby laying the foundation for further axon development and function.


Assuntos
Axônios/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Microtúbulos/metabolismo , Centrossomo/metabolismo , Humanos , Neurônios/metabolismo
20.
Dev Cell ; 56(4): 494-508.e7, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33571451

RESUMO

Neurons depend on proper localization of neurotrophic receptors in their distal processes for their function. The Trk family of neurotrophin receptors controls neuronal survival, differentiation, and remodeling and are well known to function as retrograde signal carriers transported from the distal axon toward the cell body. However, the mechanism driving anterograde trafficking of Trk receptors into the axon is not well established. We used microfluidic compartmental devices and inducible secretion assay to systematically investigate the retrograde and anterograde trafficking routes of TrkB receptor along the axon in rat hippocampal neurons. We show that newly synthesized TrkB receptors traffic through the secretory pathway and are directly delivered into axon. We found that these TrkB carriers associate and are regulated by Rab6. Furthermore, the combined activity of kinesin-1 and kinesin-3 is needed for the formation of axon-bound TrkB secretory carriers and their effective entry and processive anterograde transport beyond the proximal axon.


Assuntos
Axônios/metabolismo , Cinesinas/metabolismo , Receptor trkB/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Animais , Transporte Axonal , Endocitose , Células HEK293 , Humanos , Ratos Wistar , Via Secretória
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