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1.
Cells ; 13(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38607037

RESUMO

Zika virus (ZIKV) infection and pathogenesis are linked to the disruption of neurogenesis, congenital Zika syndrome and microcephaly by affecting neural progenitor cells. Nonstructural protein 5 (NS5) is the largest product encoded by ZIKV-RNA and is important for replication and immune evasion. Here, we studied the potential effects of NS5 on microtubules (MTs) and autophagy flux, together with the interplay of NS5 with histone deacetylase 6 (HDAC6). Fluorescence microscopy, biochemical cell-fractionation combined with the use of HDAC6 mutants, chemical inhibitors and RNA interference indicated that NS5 accumulates in nuclear structures and strongly promotes the acetylation of MTs that aberrantly reorganize in nested structures. Similarly, NS5 accumulates the p62 protein, an autophagic-flux marker. Therefore, NS5 alters events that are under the control of the autophagic tubulin-deacetylase HDAC6. HDAC6 appears to degrade NS5 by autophagy in a deacetylase- and BUZ domain-dependent manner and to control the cytoplasmic expression of NS5. Moreover, NS5 inhibits RNA-mediated RIG-I interferon (IFN) production, resulting in greater activity when autophagy is inhibited (i.e., effect correlated with NS5 stability). Therefore, it is conceivable that NS5 contributes to cell toxicity and pathogenesis, evading the IFN-immune response by overcoming HDAC6 functions. HDAC6 has emerged as an anti-ZIKV factor by targeting NS5.


Assuntos
Infecção por Zika virus , Zika virus , Humanos , Zika virus/fisiologia , Desacetilase 6 de Histona , Tubulina (Proteína) , Microtúbulos , RNA , Autofagia
2.
PLoS One ; 19(4): e0298159, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38630841

RESUMO

Snakes of the genus Boa are outstanding elements of the New World biota with a broad sociological influence on pop culture. Historically, several taxa have been recognized in the past 300 years, being mostly described in the early days of binomial nomenclature. As a rule, these taxa were recognized based on a suite of phenotypic characters mainly those from the external morphology. However, there is a huge disagreement with respect to the current taxonomy and available molecular phylogenies. In order to reconcile both lines of evidence, we investigate the phylogenetic reconstruction (using mitochondrial and nuclear genes) of the genus in parallel to the detailed study of some phenotypic systems from a geographically representative sample of the cis-Andean mainland Boa constrictor. We used cyt-b only (744bp) from 73 samples, and cyt-b, ND4, NTF3, and ODC partial sequences (in a total of 2305 bp) from 35 samples, comprising nine currently recognized taxa (species or subspecies), to infer phylogenetic relationships of boas. Topologies recovered along all the analyses and genetic distances obtained allied to a unique combination of morphological traits (colouration, pholidosis, meristic, morphometric, and male genitalia features) allowed us to recognize B. constrictor lato sensu, B. nebulosa, B. occidentalis, B. orophias and a distinct lineage from the eastern coast of Brazil, which we describe here as a new species, diagnosing it from the previously recognized taxa. Finally, we discuss the minimally necessary changes in the taxonomy of Boa constrictor complex; the value of some usually disregarded phenotypic character system; and we highlight the urgency of continuing environmental policy to preserve one of the most impacted Brazilian hotspots, the Atlantic Forest, which represents an ecoregion full of endemism.


Assuntos
Boidae , Lepidópteros , Animais , Masculino , Filogenia , Boidae/genética , Mitocôndrias/genética , Brasil
3.
iScience ; 27(1): 108600, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38179062

RESUMO

Fleas transmit Yersinia pestis directly within the dermis of mammals to cause bubonic plague. Syringe-mediated inoculation is widely used to recapitulate bubonic plague and study Y. pestis pathogenesis. However, intradermal needle inoculation is tedious, error prone, and poses a significant safety risk for laboratorians. Microneedle arrays (MNAs) are micron-scale polymeric structures that deliver materials to the dermis, while minimizing the risk of needle sticks. We demonstrated that MNA inoculation is a viable strategy to recapitulate bubonic plague and study bacterial virulence by defining the parameters needed to establish a lethal infection in the mouse model and characterizing the course of infection using live-animal optical imaging. Using MNAs, we also demonstrated that Y. pestis must overcome calprotectin-mediated zinc restriction within the dermis and dermal delivery of an attenuated mutant has vaccine potential. Together, these data demonstrate that MNAs are a safe alternative to study Y. pestis pathogenesis in the laboratory.

4.
Genome ; 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38198661

RESUMO

Cells change shape, move, divide, and die to sculpt tissues. Common to all these cell behaviours are cell size changes, which have recently emerged as key contributors to tissue morphogenesis. Cells can change their mass-the number of macromolecules they contain-or their volume-the space they encompass. Changes in cell mass and volume occur through different molecular mechanisms and at different timescales, slow for changes in mass and rapid for changes in volume. Therefore, changes in cell mass and cell volume, which are often linked, contribute to the development and shaping of tissues in different ways. Here, we review the molecular mechanisms by which cells can control and alter their size, and we discuss how changes in cell mass and volume contribute to tissue morphogenesis. The role that cell size control plays in developing embryos is only starting to be elucidated. Research on the signals that control cell size will illuminate our understanding of the cellular and molecular mechanisms that drive tissue morphogenesis.

5.
Sci Transl Med ; 16(732): eadg7895, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38295187

RESUMO

A mutation in C9ORF72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Patients with ALS or FTD often develop autoimmunity and inflammation that precedes or coincides with the onset of neurological symptoms, but the underlying mechanisms are poorly understood. Here, we knocked out murine C9orf72 in seven hematopoietic progenitor compartments by conditional mutagenesis and found that myeloid lineage C9orf72 prevents splenomegaly, loss of tolerance, and premature mortality. Furthermore, we demonstrated that C9orf72 plays a role in lymphoid cells to prevent interleukin-17A (IL-17A) production and neutrophilia. Mass cytometry identified early and sustained elevation of the costimulatory molecule CD80 expressed on C9orf72-deficient mouse macrophages, monocytes, and microglia. Enrichment of CD80 was similarly observed in human spinal cord microglia from patients with C9ORF72-mediated ALS compared with non-ALS controls. Single-cell RNA sequencing of murine spinal cord, brain cortex, and spleen demonstrated coordinated induction of gene modules related to antigen processing and presentation and antiviral immunity in C9orf72-deficient endothelial cells, microglia, and macrophages. Mechanistically, C9ORF72 repressed the trafficking of CD80 to the cell surface in response to Toll-like receptor agonists, interferon-γ, and IL-17A. Deletion of Il17a in C9orf72-deficient mice prevented CD80 enrichment in the spinal cord, reduced neutrophilia, and reduced gut T helper type 17 cells. Last, systemic delivery of an IL-17A neutralizing antibody augmented motor performance and suppressed neuroinflammation in C9orf72-deficient mice. Altogether, we show that C9orf72 orchestrates myeloid costimulatory potency and provide support for IL-17A as a therapeutic target for neuroinflammation associated with ALS or FTD.


Assuntos
Esclerose Amiotrófica Lateral , Demência Frontotemporal , Animais , Humanos , Camundongos , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Proteína C9orf72/genética , Interleucina-17 , Doenças Neuroinflamatórias , Células Endoteliais/metabolismo
6.
J Cell Sci ; 137(5)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37970744

RESUMO

Embryos repair wounds rapidly, with no inflammation or scarring. Embryonic wound healing is driven by the collective movement of the cells around the lesion. The cells adjacent to the wound polarize the cytoskeletal protein actin and the molecular motor non-muscle myosin II, which accumulate at the wound edge forming a supracellular cable around the wound. Adherens junction proteins, including E-cadherin, are internalized from the wound edge and localize to former tricellular junctions at the wound margin, in a process necessary for cytoskeletal polarity. We found that the cells adjacent to wounds in the Drosophila embryonic epidermis polarized Talin, a core component of cell-extracellular matrix (ECM) adhesions, which preferentially accumulated at the wound edge. Integrin knockdown and inhibition of integrin binding delayed wound closure and reduced actin polarization and dynamics around the wound. Additionally, disrupting integrins caused a defect in E-cadherin reinforcement at tricellular junctions along the wound edge, suggesting crosstalk between integrin-based and cadherin-based adhesions. Our results show that cell-ECM adhesion contributes to embryonic wound repair and reveal an interplay between cell-cell and cell-ECM adhesion in the collective cell movements that drive rapid wound healing.


Assuntos
Actinas , Integrinas , Animais , Actinas/metabolismo , Integrinas/metabolismo , Caderinas/metabolismo , Movimento Celular/fisiologia , Junções Intercelulares/metabolismo , Drosophila/metabolismo , Cicatrização/fisiologia , Adesão Celular
7.
Mol Biol Cell ; 35(1): ar2, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37903240

RESUMO

The Hippo pathway is an evolutionarily conserved regulator of tissue growth. Multiple Hippo signaling components are regulated via proteolytic degradation. However, how these degradation mechanisms are themselves modulated remains unexplored. Kibra is a key upstream pathway activator that promotes its own ubiquitin-mediated degradation upon assembling a Hippo signaling complex. Here, we demonstrate that Hippo complex-dependent Kibra degradation is modulated by cortical tension. Using classical genetic, osmotic, and pharmacological manipulations of myosin activity and cortical tension, we show that increasing cortical tension leads to Kibra degradation, whereas decreasing cortical tension increases Kibra abundance. Our study also implicates Par-1 in regulating Kib abundance downstream of cortical tension. We demonstrate that Par-1 promotes ubiquitin-mediated Kib degradation in a Hippo complex-dependent manner and is required for tension-induced Kib degradation. Collectively, our results reveal a previously unknown molecular mechanism by which cortical tension affects Hippo signaling and provide novel insights into the role of mechanical forces in growth control.


Assuntos
Proteínas de Drosophila , Quinase 3 da Glicogênio Sintase , Via de Sinalização Hippo , Proteólise , Proteínas Supressoras de Tumor , Ubiquitina , Animais , Drosophila melanogaster , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Drosophila/metabolismo , Estresse Mecânico
8.
Transl Vis Sci Technol ; 12(11): 38, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-38032322

RESUMO

Purpose: Diabetic retinopathy (DR) is the leading cause of vision impairment in working-age adults. Automated screening can increase DR detection at early stages at relatively low costs. We developed and evaluated a cloud-based screening tool that uses artificial intelligence (AI), the LuxIA algorithm, to detect DR from a single fundus image. Methods: Color fundus images that were previously graded by expert readers were collected from the Canarian Health Service (Retisalud) and used to train LuxIA, a deep-learning-based algorithm for the detection of more than mild DR. The algorithm was deployed in the Discovery cloud platform to evaluate each test set. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve were computed using a bootstrapping method to evaluate the algorithm performance and compared through different publicly available datasets. A usability test was performed to assess the integration into a clinical tool. Results: Three separate datasets, Messidor-2, APTOS, and a holdout set from Retisalud were evaluated. Mean sensitivity and specificity with 95% confidence intervals (CIs) reached for these three datasets were 0.901 (0.901-0.902) and 0.955 (0.955-0.956), 0.995 (0.995-0.995) and 0.821 (0.821-0.823), and 0.911 (0.907-0.912) and 0.880 (0.879-0.880), respectively. The usability test confirmed the successful integration of LuxIA into Discovery. Conclusions: Clinical data were used to train the deep-learning-based algorithm LuxIA to an expert-level performance. The whole process (image uploading and analysis) was integrated into the cloud-based platform Discovery, allowing more patients to have access to expert-level screening tools. Translational Relevance: Using the cloud-based LuxIA tool as part of a screening program may give diabetic patients greater access to specialist-level decisions, without the need for consultation.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Comportamento de Utilização de Ferramentas , Adulto , Humanos , Inteligência Artificial , Retinopatia Diabética/diagnóstico , Computação em Nuvem , Algoritmos
9.
Int J Mol Sci ; 24(17)2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37685911

RESUMO

HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Citoesqueleto , Microtúbulos , Citoesqueleto de Actina , Filamentos Intermediários
10.
Proc Natl Acad Sci U S A ; 120(39): e2305756120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37722062

RESUMO

Mutations in RNA/DNA-binding proteins cause amyotrophic lateral sclerosis (ALS), but the underlying disease mechanisms remain unclear. Here, we report that a set of ALS-associated proteins, namely FUS, EWSR1, TAF15, and MATR3, impact the expression of genes encoding the major histocompatibility complex II (MHC II) antigen presentation pathway. Both subunits of the MHC II heterodimer, HLA-DR, are down-regulated in ALS gene knockouts/knockdown in HeLa and human microglial cells, due to loss of the MHC II transcription factor CIITA. Importantly, hematopoietic progenitor cells (HPCs) derived from human embryonic stem cells bearing the FUSR495X mutation and HPCs derived from C9ORF72 ALS patient induced pluripotent stem cells also exhibit disrupted MHC II expression. Given that HPCs give rise to numerous immune cells, our data raise the possibility that loss of the MHC II pathway results in global failure of the immune system to protect motor neurons from damage that leads to ALS.


Assuntos
Esclerose Amiotrófica Lateral , Humanos , Esclerose Amiotrófica Lateral/genética , Apresentação de Antígeno/genética , Genes MHC da Classe II , Complexo Principal de Histocompatibilidade , Neurônios Motores , Proteínas de Ligação a RNA/genética , Proteínas Associadas à Matriz Nuclear
11.
Elife ; 122023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37534876

RESUMO

Background: Although there are several efficacious vaccines against COVID-19, vaccination rates in many regions around the world remain insufficient to prevent continued high disease burden and emergence of viral variants. Repurposing of existing therapeutics that prevent or mitigate severe COVID-19 could help to address these challenges. The objective of this study was to determine whether prior use of bisphosphonates is associated with reduced incidence and/or severity of COVID-19. Methods: A retrospective cohort study utilizing payer-complete health insurance claims data from 8,239,790 patients with continuous medical and prescription insurance January 1, 2019 to June 30, 2020 was performed. The primary exposure of interest was use of any bisphosphonate from January 1, 2019 to February 29, 2020. Bisphosphonate users were identified as patients having at least one bisphosphonate claim during this period, who were then 1:1 propensity score-matched to bisphosphonate non-users by age, gender, insurance type, primary-care-provider visit in 2019, and comorbidity burden. Main outcomes of interest included: (a) any testing for SARS-CoV-2 infection; (b) COVID-19 diagnosis; and (c) hospitalization with a COVID-19 diagnosis between March 1, 2020 and June 30, 2020. Multiple sensitivity analyses were also performed to assess core study outcomes amongst more restrictive matches between BP users/non-users, as well as assessing the relationship between BP-use and other respiratory infections (pneumonia, acute bronchitis) both during the same study period as well as before the COVID outbreak. Results: A total of 7,906,603 patients for whom continuous medical and prescription insurance information was available were selected. A total of 450,366 bisphosphonate users were identified and 1:1 propensity score-matched to bisphosphonate non-users. Bisphosphonate users had lower odds ratios (OR) of testing for SARS-CoV-2 infection (OR = 0.22; 95%CI:0.21-0.23; p<0.001), COVID-19 diagnosis (OR = 0.23; 95%CI:0.22-0.24; p<0.001), and COVID-19-related hospitalization (OR = 0.26; 95%CI:0.24-0.29; p<0.001). Sensitivity analyses yielded results consistent with the primary analysis. Bisphosphonate-use was also associated with decreased odds of acute bronchitis (OR = 0.23; 95%CI:0.22-0.23; p<0.001) or pneumonia (OR = 0.32; 95%CI:0.31-0.34; p<0.001) in 2019, suggesting that bisphosphonates may protect against respiratory infections by a variety of pathogens, including but not limited to SARS-CoV-2. Conclusions: Prior bisphosphonate-use was associated with dramatically reduced odds of SARS-CoV-2 testing, COVID-19 diagnosis, and COVID-19-related hospitalizations. Prospective clinical trials will be required to establish a causal role for bisphosphonate-use in COVID-19-related outcomes. Funding: This study was supported by NIH grants, AR068383 and AI155865, a grant from MassCPR (to UHvA) and a CRI Irvington postdoctoral fellowship, CRI2453 (to PH).


The COVID-19 pandemic challenged the world to rapidly develop strategies to combat the virus responsible for the disease. While several effective vaccines and new drugs have since become available, these therapies are not always easy to access and take time to generate and distribute. To address these challenges, researchers have tried to find ways to repurpose existing medications that are already commonly used and known to be safe. One potential candidate are bisphosphonates, a family of drugs used to reduce bone loss in patients with osteoporosis. Bisphosphonates have been shown to boost the immune response to viral infections, and it has been observed that patients prescribed these drugs are less likely to develop or die from pneumonia. But whether bisphosphonates are effective against COVID-19 had not been fully explored. To investigate, Thompson, Wang et al. analyzed insurance claims data from about 8 million patients between January 2019 and June 2020, including around 450,000 individuals that had filled a prescription for bisphosphonates. Patients prescribed bisphosphonates were then compared to non-users that were similar in terms of their gender, age, the type of health insurance they had, their access to healthcare, and other health comorbidities. The study revealed that bisphosphonate users were around three to five times less likely to be tested for, diagnosed with, or hospitalized for COVID-19 during the first four months of the pandemic. They were also less commonly diagnosed with other respiratory infections in 2019, like bronchitis or pneumonia. Although the results suggest that bisphosphonates provide some protection against COVID-19, they cannot directly prove it. Verifying that bisphosphonates can treat or prevent COVID-19 and/or other respiratory infections requires more studies that follow patients in real-time rather than studying previously collected data. If such studies confirm the link, bisphosphonates could be a helpful tool to protect against COVID-19 or other virus outbreaks. The drugs are widely available, safe, and affordable, and therefore may provide an alternative for patients who cannot access other medications or vaccines.


Assuntos
Bronquite , COVID-19 , Infecções Respiratórias , Humanos , COVID-19/epidemiologia , Difosfonatos/uso terapêutico , Teste para COVID-19 , SARS-CoV-2 , Estudos Retrospectivos , Vacinas contra COVID-19 , Estudos Prospectivos , Infecções Respiratórias/tratamento farmacológico , Bronquite/tratamento farmacológico
12.
Dev Cell ; 58(14): 1299-1313.e5, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37295436

RESUMO

Heart development begins with the formation of a tube as cardiac progenitors migrate from opposite sides of the embryo. Abnormal cardiac progenitor movements cause congenital heart defects. However, the mechanisms of cell migration during early heart development remain poorly understood. Using quantitative microscopy, we found that in Drosophila embryos, cardiac progenitors (cardioblasts) migrated through a sequence of forward and backward steps. Cardioblast steps were associated with oscillatory non-muscle myosin II waves that induced periodic shape changes and were necessary for timely heart tube formation. Mathematical modeling predicted that forward cardioblast migration required a stiff boundary at the trailing edge. Consistent with this, we found a supracellular actin cable at the trailing edge of the cardioblasts that limited the amplitude of the backward steps, thus biasing the direction of cell movement. Our results indicate that periodic shape changes coupled with a polarized actin cable produce asymmetrical forces that promote cardioblast migration.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Proteínas de Drosophila/fisiologia , Actinas , Coração , Miosinas , Morfogênese , Drosophila melanogaster
13.
Surg Neurol Int ; 14: 145, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37151461

RESUMO

Background: Plasma cell neoplasms are characterized by the neoplastic proliferation of a single clone of plasma cells. Solitary plasmacytomas most often occur in bone, but they can also be found in soft tissues. Case Description: A 53-year-old male presented with localized sacral pain and urinary incontinence. His radiographic studies showed a solitary sacral plasmacytoma (i.e., involving the bone). He was successfully managed with high-dose dexamethasone and microwave ablation (MWA). Conclusion: Plasmacytomas of bone can be occasionally successfully managed with MWA, adjuvant cytoreduction therapy, and high doses of dexamethasone.

14.
Materials (Basel) ; 16(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37176271

RESUMO

NO2 is one of the main greenhouse gases, which is mainly generated by the combustion of fossil fuels. In addition to its contribution to global warming, this gas is also directly dangerous to humans. The present work reports the structural and gas sensing properties of the CaCu3Ti4O12 compound prepared by the sol-gel technique. Rietveld refinement confirmed the formation of the pseudo-cubic CaCu3Ti4O12 compound, with less than 4 wt% of the secondary phases. The microstructural and elemental composition analysis were carried out using scanning electron microscopy and X-ray energy dispersive spectroscopy, respectively, while the elemental oxidation states of the samples were determined by X-ray photoelectron spectroscopy. The gas sensing response of the samples was performed for different concentrations of NO2, H2, CO, C2H2 and C2H4 at temperatures between 100 and 300 °C. The materials exhibited selectivity for NO2, showing a greater sensor signal at 250 °C, which was correlated with the highest concentration of nitrite and nitrate species on the CCTO surface using DRIFT spectroscopy.

15.
Curr Biol ; 33(13): 2587-2601.e5, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37244252

RESUMO

Collective cell movements contribute to tissue development and repair and spread metastatic disease. In epithelia, cohesive cell movements require reorganization of adherens junctions and the actomyosin cytoskeleton. However, the mechanisms that coordinate cell-cell adhesion and cytoskeletal remodeling during collective cell migration in vivo are unclear. We investigated the mechanisms of collective cell migration during epidermal wound healing in Drosophila embryos. Upon wounding, the cells adjacent to the wound internalize cell-cell adhesion molecules and polarize actin and the motor protein non-muscle myosin II to form a supracellular cable around the wound that coordinates cell movements. The cable anchors at former tricellular junctions (TCJs) along the wound edge, and TCJs are reinforced during wound closure. We found that the small GTPase Rap1 was necessary and sufficient for rapid wound repair. Rap1 promoted myosin polarization to the wound edge and E-cadherin accumulation at TCJs. Using embryos expressing a mutant form of the Rap1 effector Canoe/Afadin that cannot bind Rap1, we found that Rap1 signals through Canoe for adherens junction remodeling, but not for actomyosin cable assembly. Instead, Rap1 was necessary and sufficient for RhoA/Rho1 activation at the wound edge. The RhoGEF Ephexin localized to the wound edge in a Rap1-dependent manner, and Ephexin was necessary for myosin polarization and rapid wound repair, but not for E-cadherin redistribution. Together, our data show that Rap1 coordinates the molecular rearrangements that drive embryonic wound healing, promoting actomyosin cable assembly through Ephexin-Rho1, and E-cadherin redistribution through Canoe, thus enabling rapid collective cell migration in vivo.


Assuntos
Actomiosina , Proteínas de Drosophila , Animais , Actomiosina/metabolismo , Adesão Celular , Drosophila melanogaster/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Movimento Celular/fisiologia , Miosinas/metabolismo , Junções Aderentes/metabolismo , Caderinas/genética , Caderinas/metabolismo
16.
Curr Top Dev Biol ; 154: 99-129, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37100525

RESUMO

Actin networks are central to shaping and moving cells during animal development. Various spatial cues activate conserved signal transduction pathways to polarize actin network assembly at sub-cellular locations and to elicit specific physical changes. Actomyosin networks contract and Arp2/3 networks expand, and to affect whole cells and tissues they do so within higher-order systems. At the scale of tissues, actomyosin networks of epithelial cells can be coupled via adherens junctions to form supracellular networks. Arp2/3 networks typically integrate with distinct actin assemblies, forming expansive composites which act in conjunction with contractile actomyosin networks for whole-cell effects. This review explores these concepts using examples from Drosophila development. First, we discuss the polarized assembly of supracellular actomyosin cables which constrict and reshape epithelial tissues during embryonic wound healing, germ band extension, and mesoderm invagination, but which also form physical borders between tissue compartments at parasegment boundaries and during dorsal closure. Second, we review how locally induced Arp2/3 networks act in opposition to actomyosin structures during myoblast cell-cell fusion and cortical compartmentalization of the syncytial embryo, and how Arp2/3 and actomyosin networks also cooperate for the single cell migration of hemocytes and the collective migration of border cells. Overall, these examples show how the polarized deployment and higher-order interactions of actin networks organize developmental cell biology.


Assuntos
Actinas , Proteínas de Drosophila , Animais , Actinas/metabolismo , Drosophila , Actomiosina/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Contração Muscular , Drosophila melanogaster
17.
Int J Mol Sci ; 24(8)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37108826

RESUMO

The transactive response DNA-binding protein (TARDBP/TDP-43) is known to stabilize the anti-HIV-1 factor, histone deacetylase 6 (HDAC6). TDP-43 has been reported to determine cell permissivity to HIV-1 fusion and infection acting on tubulin-deacetylase HDAC6. Here, we studied the functional involvement of TDP-43 in the late stages of the HIV-1 viral cycle. The overexpression of TDP-43, in virus-producing cells, stabilized HDAC6 (i.e., mRNA and protein) and triggered the autophagic clearance of HIV-1 Pr55Gag and Vif proteins. These events inhibited viral particle production and impaired virion infectiveness, observing a reduction in the amount of Pr55Gag and Vif proteins incorporated into virions. A nuclear localization signal (NLS)-TDP-43 mutant was not able to control HIV-1 viral production and infection. Likewise, specific TDP-43-knockdown reduced HDAC6 expression (i.e., mRNA and protein) and increased the expression level of HIV-1 Vif and Pr55Gag proteins and α-tubulin acetylation. Thus, TDP-43 silencing favored virion production and enhanced virus infectious capacity, thereby increasing the amount of Vif and Pr55Gag proteins incorporated into virions. Noteworthy, there was a direct relationship between the content of Vif and Pr55Gag proteins in virions and their infection capacity. Therefore, for TDP-43, the TDP-43/HDAC6 axis could be considered a key factor to control HIV-1 viral production and virus infectiveness.


Assuntos
Proteínas de Ligação a DNA , Produtos do Gene gag , Produtos do Gene gag/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Processamento de Proteína Pós-Traducional , RNA Mensageiro/metabolismo
18.
Front Cardiovasc Med ; 10: 1124181, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36950285

RESUMO

Acute type A dissection presenting with cerebral malperfusion has high morbidity and mortality. Given the complexity of underlying vascular involvement, it is a challenging clinical scenario. Many of these patients are not deemed surgical candidates. If surgery is considered, it often requires complex aortic arch and neck vessel reconstruction. We present a 48-year-old male with an acute type A aortic dissection that presented with paraplegia and decreased level of consciousness. A Computed Tomography showed occlusion of both common carotid arteries. He was successfully treated with a multi-site perfusion strategy and a Hybrid Frozen Elephant Trunk graft to achieve fast restoration of the cerebral circulation and minimize brain ischemia and permanent neurological damage. From this case, we learn that aggressive arch and neck vessel reconstruction supported by multi-site perfusion could help improve mortality and neurological outcomes in selected patients.

19.
Science ; 379(6639): eabm5658, 2023 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-36996219

RESUMO

It is known that interactions between nociceptors and dendritic cells (DCs) can modulate immune responses in barrier tissues. However, our understanding of the underlying communication frameworks remains rudimentary. Here, we show that nociceptors control DCs in three molecularly distinct ways. First, nociceptors release the calcitonin gene-related peptide that imparts a distinct transcriptional profile on steady-state DCs characterized by expression of pro-interleukin-1ß and other genes implicated in DC sentinel functions. Second, nociceptor activation induces contact-dependent calcium fluxes and membrane depolarization in DCs and enhances their production of proinflammatory cytokines when stimulated. Finally, nociceptor-derived chemokine CCL2 contributes to the orchestration of DC-dependent local inflammation and the induction of adaptive responses against skin-acquired antigens. Thus, the combined actions of nociceptor-derived chemokines, neuropeptides, and electrical activity fine-tune DC responses in barrier tissues.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina , Quimiocina CCL2 , Células Dendríticas , Interleucina-1beta , Neuroimunomodulação , Nociceptores , Pele , Quimiocina CCL2/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/microbiologia , Nociceptores/metabolismo , Transdução de Sinais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Cálcio/metabolismo , Masculino , Feminino , Animais , Camundongos , Camundongos Endogâmicos C57BL , Pele/imunologia , Pele/microbiologia , Inflamação/imunologia , Inflamação/microbiologia
20.
J Clin Med ; 12(4)2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36835816

RESUMO

Mortality and re-admission rates for decompensated acute heart failure (AHF) is increasing overall and risk stratification might be challenging. We sought to evaluate the prognostic role of systemic venous ultrasonography in patients hospitalized for AHF. We prospectively recruited 74 AHF patients with a NT-proBNP level above 500 pg/mL. Then, multi-organ ultrasound assessments (lung, inferior vena cava (IVC), pulsed-wave Doppler (PW-Doppler) of hepatic, portal, intra-renal and femoral veins) were performed at admission, discharge, and follow-up (for 90 days). We also calculated the Venous Excess Ultrasound System (VExUS), a new score of systemic congestion based on IVC dilatation and pulsed-wave Doppler morphology of hepatic, portal and intra-renal veins. An intra-renal monophasic pattern (area under the curve (AUC) 0.923, sensitivity (Sn) 90%, specificity (Sp) 81%, positive predictive value (PPV) 43%, and negative predictive value (NPV) 98%), a portal pulsatility > 50% (AUC 0.749, Sn 80%, Sp 69%, PPV 30%, NPV 96%) and a VExUS score of 3 corresponding to severe congestion (AUC 0.885, Sn 80%, Sp 75%, PPV 33%, and NPV 96%) predicted death during hospitalization. An IVC above 2 cm (AUC 0.758, Sn 93.l% and Sp 58.3) and the presence of an intra-renal monophasic pattern (AUC 0. 834, sensitivity 0.917, specificity 67.4%) in the follow-up visit predicted AHF-related re-admission. Additional scans during hospitalization or the calculation of a VExUS score probably adds unnecessary complexity to the assessment of AHF patients. In conclusion, VExUS score does not contribute to the guidance of therapy or the prediction of complications, compared with the presence of an IVC greater than 2 cm, a venous monophasic intra-renal pattern or a pulsatility > 50% of the portal vein in AHF patients. Early and multidisciplinary follow-up visits remain necessary for the improvement of the prognosis of this highly prevalent disease.

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