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1.
Cells ; 13(13)2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38995001

RESUMO

BACKGROUND: Extravillous trophoblasts (EVTs) form stratified columns at the placenta-uterus interface. In the closest part to fetal structures, EVTs have a proliferative phenotype, whereas in the closest part to maternal structures, they present a migratory phenotype. During the placentation process, Connexin 40 (Cx40) participates in both the proliferation and migration of EVTs, which occurs under hypoxia. However, a possible interaction between hypoxia and Cx40 has not yet been established. METHODS: We developed two cellular models, one with "low Cx40" (Jeg-3), which reflected the expression of this protein found in migratory EVTs, and one with "high Cx40" (Jeg-3/hCx40), which reflected the expression of this protein in proliferative cells. We analyzed the migration and proliferation of these cells under normoxic and hypoxic conditions for 24 h. Jeg-3 cells under hypoxia increased their migratory capacity over their proliferative capacity. However, in Jeg-3/hCx40, the opposite effect was induced. On the other hand, hypoxia promoted gap junction (GJ) plaque formation between neighboring Jeg-3 cells. Similarly, the activation of a nitro oxide (NO)/cGMP/PKG-dependent pathway induced an increase in GJ-plaque formation in Jeg-3 cells. CONCLUSIONS: The expression patterns of Cx40 play a crucial role in shaping the responses of EVTs to hypoxia, thereby influencing their migratory or proliferative phenotype. Simultaneously, hypoxia triggers an increase in Cx40 gap junction (GJ) plaque formation through a pathway dependent on NO.


Assuntos
Hipóxia Celular , Movimento Celular , Proliferação de Células , Conexinas , Proteína alfa-5 de Junções Comunicantes , Junções Comunicantes , Trofoblastos , Trofoblastos/metabolismo , Humanos , Junções Comunicantes/metabolismo , Conexinas/metabolismo , Feminino , Gravidez , Linhagem Celular , Modelos Biológicos , Trofoblastos Extravilosos
2.
Int J Mol Sci ; 25(13)2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39000353

RESUMO

Connexins (Cxs) are transmembrane proteins that assemble into gap junction channels (GJCs) and hemichannels (HCs). Previous researches support the involvement of Rho GTPases and actin microfilaments in the trafficking of Cxs, formation of GJCs plaques, and regulation of channel activity. Nonetheless, it remains uncertain whether distinct types of Cxs HCs and GJCs respond differently to Rho GTPases or changes in actin polymerization/depolymerization dynamics. Our investigation revealed that inhibiting RhoA, a small GTPase that controls actin polymerization, or disrupting actin microfilaments with cytochalasin B (Cyto-B), resulted in reduced GJCs plaque size at appositional membranes and increased transport of HCs to non-appositional plasma membrane regions. Notably, these effects were consistent across different Cx types, since Cx26 and Cx43 exhibited similar responses, despite having distinct trafficking routes to the plasma membrane. Functional assessments showed that RhoA inhibition and actin depolymerization decreased the activity of Cx43 GJCs while significantly increasing HC activity. However, the functional status of GJCs and HCs composed of Cx26 remained unaffected. These results support the hypothesis that RhoA, through its control of the actin cytoskeleton, facilitates the transport of HCs to appositional cell membranes for GJCs formation while simultaneously limiting the positioning of free HCs at non-appositional cell membranes, independently of Cx type. This dynamic regulation promotes intercellular communications and reduces non-selective plasma membrane permeability through a Cx-type dependent mechanism, whereby the activity of Cx43 HCs and GJCs are differentially affected but Cx26 channels remain unchanged.


Assuntos
Citoesqueleto de Actina , Conexina 26 , Conexina 43 , Junções Comunicantes , Proteína rhoA de Ligação ao GTP , Citoesqueleto de Actina/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Junções Comunicantes/metabolismo , Conexina 43/metabolismo , Conexina 26/metabolismo , Humanos , Animais , Membrana Celular/metabolismo , Actinas/metabolismo
3.
Biol Res ; 57(1): 31, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38783330

RESUMO

BACKGROUND: Members of the ß-subfamily of connexins contain an intracellular pocket surrounded by amino acid residues from the four transmembrane helices. The presence of this pocket has not previously been investigated in members of the α-, γ-, δ-, and ε-subfamilies. We studied connexin50 (Cx50) as a representative of the α-subfamily, because its structure has been determined and mutations of Cx50 are among the most common genetic causes of congenital cataracts. METHODS: To investigate the presence and function of the intracellular pocket in Cx50 we used molecular dynamics simulation, site-directed mutagenesis, gap junction tracer intercellular transfer, and hemichannel activity detected by electrophysiology and by permeation of charged molecules. RESULTS: Employing molecular dynamics, we determined the presence of the intracellular pocket in Cx50 hemichannels and identified the amino acids participating in its formation. We utilized site-directed mutagenesis to alter a salt-bridge interaction that supports the intracellular pocket and occurs between two residues highly conserved in the connexin family, R33 and E162. Substitution of opposite charges at either position decreased formation of gap junctional plaques and cell-cell communication and modestly reduced hemichannel currents. Simultaneous charge reversal at these positions produced plaque-forming non-functional gap junction channels with highly active hemichannels. CONCLUSIONS: These results show that interactions within the intracellular pocket influence both gap junction channel and hemichannel functions. Disruption of these interactions may be responsible for diseases associated with mutations at these positions.


Assuntos
Conexinas , Junções Comunicantes , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Conexinas/metabolismo , Conexinas/genética , Conexinas/química , Junções Comunicantes/metabolismo , Junções Comunicantes/fisiologia , Humanos , Animais , Mutação , Comunicação Celular/fisiologia
4.
Br J Pharmacol ; 181(16): 2905-2922, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38679932

RESUMO

BACKGROUND AND PURPOSE: ATP is highly accumulated in secretory vesicles and secreted upon exocytosis from neurons and endocrine cells. In adrenal chromaffin granules, intraluminal ATP reaches concentrations over 100 mM. However, how these large amounts of ATP contribute to exocytosis has not been investigated. EXPERIMENTAL APPROACH: Exocytotic events in bovine and mouse adrenal chromaffin cells were measured with single cell amperometry. Cytosolic Ca2+ measurements were carried out in Fluo-4 loaded cells. Submembrane Ca2+ was examined in PC12 cells transfected with a membrane-tethered Ca2+ indicator Lck-GCaMP3. ATP release was measured using the luciferin/luciferase assay. Knockdown of P2X7 receptors was induced with short interfering RNA (siRNA). Direct Ca2+ influx through this receptor was measured using a P2X7 receptor-GCamp6 construct. KEY RESULTS: ATP induced exocytosis in chromaffin cells, whereas the ectonucleotidase apyrase reduced the release events induced by the nicotinic agonist dimethylphenylpiperazinium (DMPP), high KCl, or ionomycin. The purinergic agonist BzATP also promoted a secretory response that was dependent on extracellular Ca2+. A740003, a P2X7 receptor antagonist, abolished secretory responses of these secretagogues. Exocytosis was also diminished in chromaffin cells when P2X7 receptors were silenced using siRNAs and in cells of P2X7 receptor knockout mice. In PC12 cells, DMPP induced ATP release, triggering Ca2+ influx through P2X7 receptors. Furthermore, BzATP, DMPP, and KCl allowed the formation of submembrane Ca2+ microdomains inhibited by A740003. CONCLUSION AND IMPLICATIONS: Autocrine activation of P2X7 receptors constitutes a crucial feedback system that amplifies the secretion of catecholamines in chromaffin cells by favouring submembrane Ca2+ microdomains.


Assuntos
Trifosfato de Adenosina , Catecolaminas , Células Cromafins , Exocitose , Receptores Purinérgicos P2X7 , Animais , Receptores Purinérgicos P2X7/metabolismo , Células Cromafins/metabolismo , Células Cromafins/efeitos dos fármacos , Bovinos , Trifosfato de Adenosina/metabolismo , Camundongos , Catecolaminas/metabolismo , Exocitose/efeitos dos fármacos , Células PC12 , Ratos , Cálcio/metabolismo , Comunicação Autócrina , Camundongos Endogâmicos C57BL , Células Cultivadas , Masculino
5.
Heliyon ; 10(7): e27888, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38560181

RESUMO

Non-junctional connexin43 (Cx43) plasma membrane hemichannels have been implicated in several inflammatory diseases, particularly playing a role in ATP release that triggers activation of the inflammasome. Therapies targeting the blocking of the hemichannels to prevent the pathological release or uptake of ions and signalling molecules through its pores are of therapeutic interest. To date, there is no close-to-native, high-definition documentation of the impact of Cx43 hemichannel-mediated inflammation on cellular ultrastructure, neither is there a robust account of the ultrastructural changes that occur following treatment with selective Cx43 hemichannel blockers such as Xentry-Gap19 (XG19). A combination of same-sample correlative high-resolution three-dimensional fluorescence microscopy and soft X-ray tomography at cryogenic temperatures, enabled in the identification of novel 3D molecular interactions within the cellular milieu when comparing behaviour in healthy states and during the early onset or late stages under inflammatory conditions. Notably, our findings suggest that XG19 blockage of connexin hemichannels under pro-inflammatory conditions may be crucial in preventing the direct degradation of connexosomes by lysosomes, without affecting connexin protein translation and trafficking. We also delineated fine and gross cellular phenotypes, characteristic of inflammatory insult or road-to-recovery from inflammation, where XG19 could indirectly prevent and reverse inflammatory cytokine-induced mitochondrial swelling and cellular hypertrophy through its action on Cx43 hemichannels. Our findings suggest that XG19 might have prophylactic and therapeutic effects on the inflammatory response, in line with functional studies.

6.
BMC Public Health ; 24(1): 990, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594646

RESUMO

BACKGROUND: Despite multiple recommendations and strategies implemented at a national and international level, cigarette smoking, alcohol consumption, and cannabis use during pregnancy remains high in most countries. The objective of this study was to examine key stakeholders' perception of the treatment interventions adopted in Spain, to identify political, organizational and personal factors associated with successful implementation, and to propose strategies for improvement. METHODS: A qualitative study with a phenomenological approach was conducted in 2022. The target groups were: (1) clinical decision makers in the field of addiction science, (2) health professionals who carry out treatment interventions, and (3) pregnant individuals who use tobacco, alcohol or cannabis. Two focus groups and eight in-depth interviews were conducted, recorded, and transcribed. Exploratory analysis and inductive open coding was performed, codes were merged into categories, and subcategories were identified. RESULTS: The analysis resulted in 10 subcategories which were further merged into three main categories: (1) Degree of adoption and utility of treatment interventions implemented; (2) Needs and demands with respect to the organization of treatment interventions; and, (3) Personal barriers to and facilitators for treatment. Respondents reported that despite multiple national and regional cessation initiatives, treatment interventions were rarely adopted in clinical practice. Health care administrators demanded reliable records to quantify substance use for better planning of activities. Health care professionals advocated for additional time and training and both echoed the importance of integrating cessation interventions into routine prenatal care and creating in-house specialized units. The difficulty in quitting, lack of awareness of risk for foetus and child and the controversial advice were identified as barriers by pregnant individuals. CONCLUSIONS: Consistent with previous work, this study found that cessation strategies implemented by the health authorities are not effective if they are not accompanied by organizational and behavioral changes. The current study identifies a set of factors that could be pivotal in ensuring the success of treatment interventions targeting tobacco, alcohol and cannabis use among pregnant individuals.


Assuntos
Abandono do Hábito de Fumar , Feminino , Humanos , Gravidez , Tomada de Decisões , Etanol , Percepção , Cuidado Pré-Natal , Pesquisa Qualitativa , Abandono do Hábito de Fumar/métodos
7.
Toxicon ; 241: 107665, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38428752

RESUMO

The pods of Neltuma spp. have shown potential as a source of protein and energy in livestock. However, prolonged consumption of some of these species can lead to neurological symptoms in ruminants. This study aimed to determine the alkaloid content, as well as the in vitro and in vivo effects of an alkaloid-enriched extract (AEE) from N. alpataco pods. High performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) identified juliprosine and juliprosopine as primary alkaloids, with juliprosine being most abundant. AEE from N. alpataco demonstrated dose-dependent cytotoxicity on glioma cells after 48 h, with a 50% cytotoxic concentration (CC50) of 24.69 µg/mL. However, the release of LDH was observed only at the highest tested concentration, indicating cellular damage. Further examination through phase-contrast microscopy and dual acridine orange/ethidium bromide fluorescence staining revealed morphological changes consistent with an apoptotic mechanism of cell death, ultimately leading to secondary necrosis. Finally, the LD50 after intraperitoneal injection in mice was determined to be 12.98 mg/kg. Taken together, these findings demonstrated for the first time the in vivo and in vitro toxicity of the AEE from N. alpataco pods.


Assuntos
Alcaloides , Antineoplásicos , Prosopis , Camundongos , Animais , Alcaloides/química , Extratos Vegetais/farmacologia , Antineoplásicos/farmacologia , Apoptose
8.
Sci Rep ; 14(1): 6791, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514697

RESUMO

Extracellular vesicles (EVs) released from cells attract interest for their possible role in health and diseases. The detection and characterization of EVs is challenging due to the lack of specialized methodologies. Raman spectroscopy, however, has been suggested as a novel approach for biochemical analysis of EVs. To extract information from the spectra, a novel deep learning architecture is explored as a versatile variant of autoencoders. The proposed architecture considers the frequency range separately from the intensity of the spectra. This enables the model to adapt to the frequency range, rather than requiring that all spectra be pre-processed to the same frequency range as it was trained on. It is demonstrated that the proposed architecture accepts Raman spectra of EVs and lipoproteins from 13 biological sources and from two laboratories. High reconstruction accuracy is maintained despite large variances in frequency range and noise level. It is also shown that the architecture is able to cluster the biological nanoparticles by their Raman spectra and differentiate them by their origin without pre-processing of the spectra or supervision during learning. The model performs label-free differentiation, including separating EVs from activated vs. non-activated blood platelets and EVs/lipoproteins from prostate cancer patients versus non-cancer controls. The differentiation is evaluated by creating a neural network classifier that observes the features extracted by the model to classify the spectra according to their sample origin. The classification reveals a test sensitivity of 92.2 % and selectivity of 92.3 % over 769 measurements from two labs that have different measurement configurations.


Assuntos
Vesículas Extracelulares , Nanopartículas , Neoplasias da Próstata , Masculino , Humanos , Vesículas Extracelulares/química , Neoplasias da Próstata/diagnóstico , Lipoproteínas , Aprendizado de Máquina Supervisionado , Análise Espectral Raman/métodos
9.
Muscle Nerve ; 69(4): 472-476, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38299438

RESUMO

INTRODUCTION/AIMS: Limb-girdle muscular dystrophy R1 (LGMDR1) calpain 3-related usually presents as a recessively transmitted weakness of proximal limb-girdle muscles due to pathogenic variants in the CAPN3 gene. Pathogenic variants in this gene have also been found in patients with an autosomal dominantly inherited transmission pattern (LGMDD4). The mechanism underlying this difference in transmission patterns has not yet been elucidated. Camptocormia, progressive limb weakness, myalgia, back pain, and increased CK levels are common clinical features associated with dominant forms. The p.Lys254del pathogenic variant was associated with camptocormia in two LGMDD4 families. This study aimed to present carriers found in recessively transmitted LGMDR1 families bearing the p.Lys254del variant that do not show muscle weakness. METHODS: DNA sequencing was performed on exon 5 of CAPN3 in family members to establish the carrier status of the pathogenic variant. They were evaluated clinically and MRI was performed when available. RESULTS: Two families presented with the p.Lys254del pathogenic variant in a homozygous or compound heterozygous state. Family members carrying only the pathogenic variant in the heterozygous state did not demonstrate the myopathic characteristics described in dominant patients. Camptocormia and other severe clinical symptoms were not observed. DISCUSSION: We conclude that the p.Lys254del pathogenic variant per se cannot be solely responsible for camptocormia in dominant patients. Other undisclosed factors may regulate the phenotype associated with the dominant inheritance pattern in CAPN3 pathogenic variant carriers.


Assuntos
Calpaína , Atrofia Muscular Espinal , Distrofia Muscular do Cíngulo dos Membros , Curvaturas da Coluna Vertebral , Humanos , Calpaína/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Debilidade Muscular , Família , Paresia , Mutação/genética , Proteínas Musculares/genética
10.
Rev. esp. enferm. dig ; 115(12): 682-685, Dic. 2023. ilus
Artigo em Inglês, Espanhol | IBECS | ID: ibc-228702

RESUMO

La trombosis venosa portal es una complicación infrecuente de los pacientes con cirrosis, que habitualmente aparece en las fases más avanzadas de la enfermedad. Aunque no disponemos de una evidencia sólida, la anticoagulación está indicada en algunos grupos de pacientes en los que la gravedad de la oclusión portal o en los que su especial situación de cara al trasplante requiere intentar la recanalización portal. Más allá de la recanalización, la anticoagulación parece tener un efecto beneficioso en la historia natural de la cirrosis, lo que plantea dudas sobre la oportunidad de su retirada una vez iniciada.(AU)


Assuntos
Humanos , Masculino , Feminino , Cirrose Hepática/complicações , Trombose Venosa/tratamento farmacológico , Hipertensão Portal , Anticoagulantes/administração & dosagem , Trombose Venosa/complicações , Fatores de Risco , Doenças do Sistema Digestório
11.
J Extracell Vesicles ; 12(11): e12376, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37942918

RESUMO

Extracellular vesicles (EVs) in blood plasma are recognized as potential biomarkers for disease. Although blood plasma is easily obtainable, analysis of EVs at the single particle level is still challenging due to the biological complexity of this body fluid. Besides EVs, plasma contains different types of lipoproteins particles (LPPs), that outnumber EVs by orders of magnitude and which partially overlap in biophysical properties such as size, density and molecular makeup. Consequently, during EV isolation LPPs are often co-isolated. Furthermore, physical EV-LPP complexes have been observed in purified EV preparations. Since co-isolation or association of LPPs can impact EV-based analysis and biomarker profiling, we investigated the presence and formation of EV-LPP complexes in biological samples by using label-free atomic force microscopy, cryo-electron tomography and synchronous Rayleigh and Raman scattering analysis of optically trapped particles and fluorescence-based high sensitivity single particle flow cytometry. Furthermore, we evaluated the impact on flow cytometric analysis in the presence of LPPs using in vitro spike-in experiments of purified tumour cell line-derived EVs in different classes of purified human LPPs. Based on orthogonal single-particle analysis techniques we demonstrate that EV-LPP complexes can form under physiological conditions. Furthermore, we show that in fluorescence-based flow cytometric EV analysis staining of LPPs, as well as EV-LPP associations, can influence quantitative and qualitative EV analysis. Lastly, we demonstrate that the colloidal matrix of the biofluid in which EVs reside impacts their buoyant density, size and/or refractive index (RI), which may have consequences for down-stream EV analysis and EV biomarker profiling.


Assuntos
Vesículas Extracelulares , Humanos , Vesículas Extracelulares/fisiologia , Imagem Individual de Molécula , Biomarcadores , Linhagem Celular Tumoral , Lipoproteínas LDL
12.
Aten. prim. (Barc., Ed. impr.) ; 55(11): 102732, Nov. 2023. tab
Artigo em Espanhol | IBECS | ID: ibc-227010

RESUMO

Objetivo: Explorar la opinión de distintos actores clave, en relación con los requisitos que deberían cumplir las intervenciones de cesación de consumo de tabaco, alcohol y/o cannabis durante el embarazo para que puedan ser implementadas y resulten aceptables y útiles. Diseño: Estudio cualitativo con aproximación fenomenológica. Sitio: Se realizó en España en 2022. Participantes: Gestores, profesionales sanitarios, embarazadas consumidoras de tabaco, alcohol y/o cannabis y sus parejas también consumidoras. Métodos: Los datos se recogieron mediante grupos focales y entrevistas en profundidad, hasta alcanzar la saturación del discurso y se transcribieron de manera exacta. Se realizó un análisis exploratorio y codificación abierta inductiva, se fusionaron los códigos en categorías y se identificaron subcategorías. Resultados: Se identificaron cuatro categorías y 18 subcategorías. Los resultados apuntan a que las intervenciones deberían de ser multicomponente. Entre las intervenciones más aceptadas por parte de las mujeres embarazadas y sus parejas, las consultas específicas de cesación, la información, el apoyo de un igual (aunque no precisan de qué manera) y los incentivos económicos. Entre otras opciones a considerar, la cooximetría, propuesta por gestores para obtener un registro objetivo. Conclusiones: Se extrae que esta intervención debe realizarse a nivel de la atención prenatal realizada en atención primaria. Existen dudas respecto de la frecuencia, fin y seguimiento de esta intervención multicomponente, así como a la posibilidad de incorporar a las parejas.(AU)


Objective: To explore the opinion of different key stakeholders regarding the requirements that tobacco, alcohol and/or cannabis cessation interventions should meet to be implemented and to be acceptable and useful during pregnancy. Design: A qualitative study with phenomenological approach. Site: The study was conducted in Spain in 2022. Participants: Decision makers, health professionals, pregnant women using tobacco, alcohol and/or cannabis and their partners who are also users. Methods: Data were collected through focus groups and in-depth interviews, until discourse saturation was reached and accurately transcribed. Exploratory analysis and inductive open coding were conducted, codes were merged into categories and subcategories were identified. Results: Four categories and 18 subcategories were identified. The results suggest that interventions should be multicomponent. Among the interventions most accepted by pregnant women and their partners were specific cessation consultations, information, peer support (although they did not specify how) and financial incentives. Among other options to consider, co-oximetry, proposed by managers to obtain an objective register. Conclusions: The conclusion is that this intervention should be carried out at the level of prenatal care in primary care. There are doubts regarding the frequency, purpose, and follow-up of this multicomponent intervention, as well as the possibility of incorporating couples.(AU)


Assuntos
Humanos , Feminino , Gravidez , Gestantes , Abandono do Uso de Tabaco , Uso de Tabaco , Fumar Tabaco , Fumar Maconha/efeitos adversos , Consumo de Bebidas Alcoólicas , Pesquisa Qualitativa , Nicotiana , Cannabis , Abuso de Maconha , Uso da Maconha , Espanha , Grupos Focais , Inquéritos e Questionários , Transtornos Relacionados ao Uso de Substâncias
13.
Aten Primaria ; 55(11): 102732, 2023 Aug 11.
Artigo em Espanhol | MEDLINE | ID: mdl-37573833

RESUMO

OBJECTIVE: To explore the opinion of different key stakeholders regarding the requirements that tobacco, alcohol and/or cannabis cessation interventions should meet to be implemented and to be acceptable and useful during pregnancy. DESIGN: A qualitative study with phenomenological approach. SITE: The study was conducted in Spain in 2022. PARTICIPANTS: Decision makers, health professionals, pregnant women using tobacco, alcohol and/or cannabis and their partners who are also users. METHODS: Data were collected through focus groups and in-depth interviews, until discourse saturation was reached and accurately transcribed. Exploratory analysis and inductive open coding were conducted, codes were merged into categories and subcategories were identified. RESULTS: Four categories and 18 subcategories were identified. The results suggest that interventions should be multicomponent. Among the interventions most accepted by pregnant women and their partners were specific cessation consultations, information, peer support (although they did not specify how) and financial incentives. Among other options to consider, co-oximetry, proposed by managers to obtain an objective register. CONCLUSIONS: The conclusion is that this intervention should be carried out at the level of prenatal care in primary care. There are doubts regarding the frequency, purpose, and follow-up of this multicomponent intervention, as well as the possibility of incorporating couples.

15.
Proc Natl Acad Sci U S A ; 120(31): e2307898120, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37487087

RESUMO

Cells of vertebrate and invertebrate organisms express proteins specialized in membrane channel-based cell-cell communication that are absent in unicellular organisms. We recently described the prediction of some members of the large-pore channel family in kinetoplastids, consisting of proteins called unnexins, which share several structural features with innexin and pannexin proteins. Here, we demonstrated that the unnexin1 protein (Unx1) is delivered to the cell membrane, displaying a topology consisting of four transmembrane domains with C and N termini on the cytoplasmic side and form large-pore channels that are permeable to small molecules. Low extracellular Ca2+/Mg2+ levels or extracellular alkalinization, but not mechanical stretching, increases channel activity. The Unx1 channel mediates the influx of Ca2+ and does not form intercellular dye coupling between HeLa Unx1 transfected cells. Unx1 channel function was further evidenced by its ability to mediate ionic currents when expressed in Xenopus oocytes. Downregulation of Unx1 mRNA with morpholine contains Trypanosoma cruzi invasion. Phylogenetic analysis revealed the presence of Unx1 homologs in other protozoan parasites, suggesting a conserved function for these channel parasites in other protists. Our data demonstrate that Unx1 forms large-pore membrane channels, which may serve as a diffusional pathway for ions and small molecules that are likely to be metabolic substrates or waste products, and signaling autocrine and paracrine molecules that could be involved in cell invasion. As morpholinos-induced downregulation of Unx1 reduces the infectivity of trypomastigotes, the Unx1 channels might be an attractive target for developing trypanocide drugs.


Assuntos
Subunidades Proteicas , Filogenia , Membrana Celular , Citoplasma , Morfolinos
16.
Rev Esp Enferm Dig ; 115(12): 682-685, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37522304

RESUMO

Portal vein thrombosis is an uncommon complication in patients with cirrhosis, typically manifesting in the advanced stages of the disease. Although robust evidence is lacking, anticoagulation is indicated in specific patient subgroups, either those with severe portal occlusion or those requiring attempted portal recanalization due to their unique transplant situation. Beyond recanalization, anticoagulation appears to exert a beneficial effect on the natural history of cirrhosis, which raises uncertainties about the appropriateness of discontinuing it once initiated.


Assuntos
Anticoagulantes , Trombose Venosa , Humanos , Anticoagulantes/uso terapêutico , Veia Porta , Trombose Venosa/diagnóstico por imagem , Trombose Venosa/tratamento farmacológico , Trombose Venosa/etiologia , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Resultado do Tratamento
17.
Biomolecules ; 13(6)2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-37371467

RESUMO

Pannexin-1 (Panx1) hemichannel is a non-selective transmembrane channel that may play important roles in intercellular signaling by allowing the permeation of ions and metabolites, such as ATP. Although recent evidence shows that the Panx1 hemichannel is involved in controlling excitatory synaptic transmission, the role of Panx1 in inhibitory transmission remains unknown. Here, we studied the contribution of Panx1 to the GABAergic synaptic efficacy onto CA1 pyramidal neurons (PyNs) by using patch-clamp recordings and pharmacological approaches in wild-type and Panx1 knock-out (Panx1-KO) mice. We reported that blockage of the Panx1 hemichannel with the mimetic peptide 10Panx1 increases the synaptic level of endocannabinoids (eCB) and the activation of cannabinoid receptors type 1 (CB1Rs), which results in a decrease in hippocampal GABAergic efficacy, shifting excitation/inhibition (E/I) balance toward excitation and facilitating the induction of long-term potentiation. Our finding provides important insight unveiling that Panx1 can strongly influence the overall neuronal excitability and play a key role in shaping synaptic changes affecting the amplitude and direction of plasticity, as well as learning and memory processes.


Assuntos
Hipocampo , Proteínas do Tecido Nervoso , Plasticidade Neuronal , Células Piramidais , Animais , Camundongos , Conexinas/genética , Conexinas/metabolismo , Hipocampo/metabolismo , Potenciação de Longa Duração/fisiologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Plasticidade Neuronal/genética , Plasticidade Neuronal/fisiologia , Células Piramidais/metabolismo , Células Piramidais/fisiologia , Transmissão Sináptica
18.
J Endourol ; 37(8): 935-939, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37337653

RESUMO

Purpose: On February 6, 2018, the European Atomic Energy Community reduced the annual equivalent dose limit for the lens from 150 to 20 mSv/year, because of its association with cataracts at low radiation doses. Our aim was to estimate the radiation doses received by the lens during endourologic procedures that require fluoroscopy. Materials and Methods: Multicenter study including prospective data of annual eye dosimeters between 2017 and 2020. Four endourologists used an eye dosimeter in endourologic procedures that require fluoroscopy (ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy). Surgeons 1 and 2 wore leaded glasses; surgeon 1 also used the as low as reasonably achievable (ALARA) protocol. Descriptive statistical analysis using SPSS 25.0 was conducted. Results: Surgeons 1, 2, 3, and 4 performed a median of 159, 586, 102, and 129 endourologic procedures per year, respectively, for a total of 641, 2340, 413, and 350 procedures between 2017 and 2020. The median annual dose of lens radiation exposure was 0.16, 1.18, 3.79, and 1.42 mSv per year, respectively, which corresponds to 0.001, 0.009, 0.024, and 0.012 mSv per procedure. The two surgeons who used leaded glasses registered a lower radiation dose per procedure (0.001 vs 0.027). Similarly, the urologist who used the ALARA protocol registered the lowest lens radiation dose compared with the three surgeons who did not use it (0.001 vs 0.023). Conclusions: The endourologists who participated in this study effectively comply with current guidelines on radiation exposure to the lens. Registered eye lens radiation does not seem to be related to the number of procedures but rather to the use of leaded glasses and the ALARA protocol.


Assuntos
Cristalino , Exposição Ocupacional , Exposição à Radiação , Humanos , Estudos Prospectivos , Doses de Radiação , Fluoroscopia/efeitos adversos , Estudos Multicêntricos como Assunto
19.
Rev Esp Enferm Dig ; 115(5): 223-224, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37114390

RESUMO

Gastrointestinal (GI) Endoscopy is a basic competence for the management of gastrointestinal diseases. However, it should not be regarded as an independent training technique. Rather it is a part of a continuous and accredited process that requires clinical knowledge from the gastroenterologist to keep skills up-to-date in a constantly evolving medical subspecialty. Thus, the only official accredited way for training in GI endoscopy is through the Specialized Health Training program in the Management of the Digestive Diseases administered by the Spanish Ministry of Health.


Assuntos
Gastroenterologistas , Gastroenteropatias , Humanos , Endoscopia Gastrointestinal/métodos , Currículo , Gastroenteropatias/diagnóstico por imagem , Gastroenteropatias/terapia , Competência Clínica
20.
Acta Otolaryngol ; 143(3): 242-249, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36943799

RESUMO

BACKGROUND: Cisplatin appears to enter the cochlear cells through the organic cation transporter 2 (OCT2). There is recent evidence that multidrug and toxin extrusion protein 1 (MATE1) is involved in cisplatin-induced nephrotoxicity. Its presence and role in the ear are unknown. AIMS/OBJECTIVES: Evaluate the presence and localization of MATE1, and determine the localization of OCT2, in the cochlea. Evaluate cisplatin uptake with regard to MATE1 and OCT2 expression. MATERIAL AND METHODS: Murine cochlear explants and paraffin-embedded cochleae were evaluated with immunohistochemistry for OCT2 and MATE1. Explant cultures were also treated with Texas Red cisplatin to determine their cellular uptake. RESULTS: MATE1 is present in the cochlea. Most intense labeling of MATE1 and OCT2 was seen in the outer hair cells (OHCs) and pillar cells, respectively. Both transporters were observed in the spiral ganglion neurons and stria vascularis. Expression levels of OCT2 and MATE1 decreased following cisplatin exposure. Texas Red cisplatin staining was strong in OHCs and pillar cells. CONCLUSIONS AND SIGNIFICANCE: To the best of our knowledge, this is the first study demonstrating the presence and localization of MATE1 in the cochlea. OCT2 labeling was seen in pillar cells. Consistently, OHCs and pillar cells uptake Texas Red cisplatin.


Assuntos
Cisplatino , Ototoxicidade , Camundongos , Animais , Cisplatino/toxicidade , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Cóclea/metabolismo
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